tree-wide: fix assorted typos all over the place
[safe/jmp/linux-2.6] / fs / ocfs2 / alloc.c
index 85a05f1..7c7198a 100644 (file)
@@ -27,6 +27,8 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/highmem.h>
+#include <linux/swap.h>
+#include <linux/quotaops.h>
 
 #define MLOG_MASK_PREFIX ML_DISK_ALLOC
 #include <cluster/masklog.h>
@@ -34,6 +36,8 @@
 #include "ocfs2.h"
 
 #include "alloc.h"
+#include "aops.h"
+#include "blockcheck.h"
 #include "dlmglue.h"
 #include "extent_map.h"
 #include "inode.h"
 #include "file.h"
 #include "super.h"
 #include "uptodate.h"
+#include "xattr.h"
+#include "refcounttree.h"
 
 #include "buffer_head_io.h"
 
-static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc);
+enum ocfs2_contig_type {
+       CONTIG_NONE = 0,
+       CONTIG_LEFT,
+       CONTIG_RIGHT,
+       CONTIG_LEFTRIGHT,
+};
 
+static enum ocfs2_contig_type
+       ocfs2_extent_rec_contig(struct super_block *sb,
+                               struct ocfs2_extent_rec *ext,
+                               struct ocfs2_extent_rec *insert_rec);
 /*
- * Structures which describe a path through a btree, and functions to
- * manipulate them.
+ * Operations for a specific extent tree type.
  *
- * The idea here is to be as generic as possible with the tree
- * manipulation code.
+ * To implement an on-disk btree (extent tree) type in ocfs2, add
+ * an ocfs2_extent_tree_operations structure and the matching
+ * ocfs2_init_<thingy>_extent_tree() function.  That's pretty much it
+ * for the allocation portion of the extent tree.
+ */
+struct ocfs2_extent_tree_operations {
+       /*
+        * last_eb_blk is the block number of the right most leaf extent
+        * block.  Most on-disk structures containing an extent tree store
+        * this value for fast access.  The ->eo_set_last_eb_blk() and
+        * ->eo_get_last_eb_blk() operations access this value.  They are
+        *  both required.
+        */
+       void (*eo_set_last_eb_blk)(struct ocfs2_extent_tree *et,
+                                  u64 blkno);
+       u64 (*eo_get_last_eb_blk)(struct ocfs2_extent_tree *et);
+
+       /*
+        * The on-disk structure usually keeps track of how many total
+        * clusters are stored in this extent tree.  This function updates
+        * that value.  new_clusters is the delta, and must be
+        * added to the total.  Required.
+        */
+       void (*eo_update_clusters)(struct ocfs2_extent_tree *et,
+                                  u32 new_clusters);
+
+       /*
+        * If this extent tree is supported by an extent map, insert
+        * a record into the map.
+        */
+       void (*eo_extent_map_insert)(struct ocfs2_extent_tree *et,
+                                    struct ocfs2_extent_rec *rec);
+
+       /*
+        * If this extent tree is supported by an extent map, truncate the
+        * map to clusters,
+        */
+       void (*eo_extent_map_truncate)(struct ocfs2_extent_tree *et,
+                                      u32 clusters);
+
+       /*
+        * If ->eo_insert_check() exists, it is called before rec is
+        * inserted into the extent tree.  It is optional.
+        */
+       int (*eo_insert_check)(struct ocfs2_extent_tree *et,
+                              struct ocfs2_extent_rec *rec);
+       int (*eo_sanity_check)(struct ocfs2_extent_tree *et);
+
+       /*
+        * --------------------------------------------------------------
+        * The remaining are internal to ocfs2_extent_tree and don't have
+        * accessor functions
+        */
+
+       /*
+        * ->eo_fill_root_el() takes et->et_object and sets et->et_root_el.
+        * It is required.
+        */
+       void (*eo_fill_root_el)(struct ocfs2_extent_tree *et);
+
+       /*
+        * ->eo_fill_max_leaf_clusters sets et->et_max_leaf_clusters if
+        * it exists.  If it does not, et->et_max_leaf_clusters is set
+        * to 0 (unlimited).  Optional.
+        */
+       void (*eo_fill_max_leaf_clusters)(struct ocfs2_extent_tree *et);
+
+       /*
+        * ->eo_extent_contig test whether the 2 ocfs2_extent_rec
+        * are contiguous or not. Optional. Don't need to set it if use
+        * ocfs2_extent_rec as the tree leaf.
+        */
+       enum ocfs2_contig_type
+               (*eo_extent_contig)(struct ocfs2_extent_tree *et,
+                                   struct ocfs2_extent_rec *ext,
+                                   struct ocfs2_extent_rec *insert_rec);
+};
+
+
+/*
+ * Pre-declare ocfs2_dinode_et_ops so we can use it as a sanity check
+ * in the methods.
  */
-struct ocfs2_path_item {
-       struct buffer_head              *bh;
-       struct ocfs2_extent_list        *el;
+static u64 ocfs2_dinode_get_last_eb_blk(struct ocfs2_extent_tree *et);
+static void ocfs2_dinode_set_last_eb_blk(struct ocfs2_extent_tree *et,
+                                        u64 blkno);
+static void ocfs2_dinode_update_clusters(struct ocfs2_extent_tree *et,
+                                        u32 clusters);
+static void ocfs2_dinode_extent_map_insert(struct ocfs2_extent_tree *et,
+                                          struct ocfs2_extent_rec *rec);
+static void ocfs2_dinode_extent_map_truncate(struct ocfs2_extent_tree *et,
+                                            u32 clusters);
+static int ocfs2_dinode_insert_check(struct ocfs2_extent_tree *et,
+                                    struct ocfs2_extent_rec *rec);
+static int ocfs2_dinode_sanity_check(struct ocfs2_extent_tree *et);
+static void ocfs2_dinode_fill_root_el(struct ocfs2_extent_tree *et);
+static struct ocfs2_extent_tree_operations ocfs2_dinode_et_ops = {
+       .eo_set_last_eb_blk     = ocfs2_dinode_set_last_eb_blk,
+       .eo_get_last_eb_blk     = ocfs2_dinode_get_last_eb_blk,
+       .eo_update_clusters     = ocfs2_dinode_update_clusters,
+       .eo_extent_map_insert   = ocfs2_dinode_extent_map_insert,
+       .eo_extent_map_truncate = ocfs2_dinode_extent_map_truncate,
+       .eo_insert_check        = ocfs2_dinode_insert_check,
+       .eo_sanity_check        = ocfs2_dinode_sanity_check,
+       .eo_fill_root_el        = ocfs2_dinode_fill_root_el,
+};
+
+static void ocfs2_dinode_set_last_eb_blk(struct ocfs2_extent_tree *et,
+                                        u64 blkno)
+{
+       struct ocfs2_dinode *di = et->et_object;
+
+       BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
+       di->i_last_eb_blk = cpu_to_le64(blkno);
+}
+
+static u64 ocfs2_dinode_get_last_eb_blk(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_dinode *di = et->et_object;
+
+       BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
+       return le64_to_cpu(di->i_last_eb_blk);
+}
+
+static void ocfs2_dinode_update_clusters(struct ocfs2_extent_tree *et,
+                                        u32 clusters)
+{
+       struct ocfs2_inode_info *oi = cache_info_to_inode(et->et_ci);
+       struct ocfs2_dinode *di = et->et_object;
+
+       le32_add_cpu(&di->i_clusters, clusters);
+       spin_lock(&oi->ip_lock);
+       oi->ip_clusters = le32_to_cpu(di->i_clusters);
+       spin_unlock(&oi->ip_lock);
+}
+
+static void ocfs2_dinode_extent_map_insert(struct ocfs2_extent_tree *et,
+                                          struct ocfs2_extent_rec *rec)
+{
+       struct inode *inode = &cache_info_to_inode(et->et_ci)->vfs_inode;
+
+       ocfs2_extent_map_insert_rec(inode, rec);
+}
+
+static void ocfs2_dinode_extent_map_truncate(struct ocfs2_extent_tree *et,
+                                            u32 clusters)
+{
+       struct inode *inode = &cache_info_to_inode(et->et_ci)->vfs_inode;
+
+       ocfs2_extent_map_trunc(inode, clusters);
+}
+
+static int ocfs2_dinode_insert_check(struct ocfs2_extent_tree *et,
+                                    struct ocfs2_extent_rec *rec)
+{
+       struct ocfs2_inode_info *oi = cache_info_to_inode(et->et_ci);
+       struct ocfs2_super *osb = OCFS2_SB(oi->vfs_inode.i_sb);
+
+       BUG_ON(oi->ip_dyn_features & OCFS2_INLINE_DATA_FL);
+       mlog_bug_on_msg(!ocfs2_sparse_alloc(osb) &&
+                       (oi->ip_clusters != le32_to_cpu(rec->e_cpos)),
+                       "Device %s, asking for sparse allocation: inode %llu, "
+                       "cpos %u, clusters %u\n",
+                       osb->dev_str,
+                       (unsigned long long)oi->ip_blkno,
+                       rec->e_cpos, oi->ip_clusters);
+
+       return 0;
+}
+
+static int ocfs2_dinode_sanity_check(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_dinode *di = et->et_object;
+
+       BUG_ON(et->et_ops != &ocfs2_dinode_et_ops);
+       BUG_ON(!OCFS2_IS_VALID_DINODE(di));
+
+       return 0;
+}
+
+static void ocfs2_dinode_fill_root_el(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_dinode *di = et->et_object;
+
+       et->et_root_el = &di->id2.i_list;
+}
+
+
+static void ocfs2_xattr_value_fill_root_el(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_xattr_value_buf *vb = et->et_object;
+
+       et->et_root_el = &vb->vb_xv->xr_list;
+}
+
+static void ocfs2_xattr_value_set_last_eb_blk(struct ocfs2_extent_tree *et,
+                                             u64 blkno)
+{
+       struct ocfs2_xattr_value_buf *vb = et->et_object;
+
+       vb->vb_xv->xr_last_eb_blk = cpu_to_le64(blkno);
+}
+
+static u64 ocfs2_xattr_value_get_last_eb_blk(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_xattr_value_buf *vb = et->et_object;
+
+       return le64_to_cpu(vb->vb_xv->xr_last_eb_blk);
+}
+
+static void ocfs2_xattr_value_update_clusters(struct ocfs2_extent_tree *et,
+                                             u32 clusters)
+{
+       struct ocfs2_xattr_value_buf *vb = et->et_object;
+
+       le32_add_cpu(&vb->vb_xv->xr_clusters, clusters);
+}
+
+static struct ocfs2_extent_tree_operations ocfs2_xattr_value_et_ops = {
+       .eo_set_last_eb_blk     = ocfs2_xattr_value_set_last_eb_blk,
+       .eo_get_last_eb_blk     = ocfs2_xattr_value_get_last_eb_blk,
+       .eo_update_clusters     = ocfs2_xattr_value_update_clusters,
+       .eo_fill_root_el        = ocfs2_xattr_value_fill_root_el,
+};
+
+static void ocfs2_xattr_tree_fill_root_el(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_xattr_block *xb = et->et_object;
+
+       et->et_root_el = &xb->xb_attrs.xb_root.xt_list;
+}
+
+static void ocfs2_xattr_tree_fill_max_leaf_clusters(struct ocfs2_extent_tree *et)
+{
+       struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
+       et->et_max_leaf_clusters =
+               ocfs2_clusters_for_bytes(sb, OCFS2_MAX_XATTR_TREE_LEAF_SIZE);
+}
+
+static void ocfs2_xattr_tree_set_last_eb_blk(struct ocfs2_extent_tree *et,
+                                            u64 blkno)
+{
+       struct ocfs2_xattr_block *xb = et->et_object;
+       struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;
+
+       xt->xt_last_eb_blk = cpu_to_le64(blkno);
+}
+
+static u64 ocfs2_xattr_tree_get_last_eb_blk(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_xattr_block *xb = et->et_object;
+       struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;
+
+       return le64_to_cpu(xt->xt_last_eb_blk);
+}
+
+static void ocfs2_xattr_tree_update_clusters(struct ocfs2_extent_tree *et,
+                                            u32 clusters)
+{
+       struct ocfs2_xattr_block *xb = et->et_object;
+
+       le32_add_cpu(&xb->xb_attrs.xb_root.xt_clusters, clusters);
+}
+
+static struct ocfs2_extent_tree_operations ocfs2_xattr_tree_et_ops = {
+       .eo_set_last_eb_blk     = ocfs2_xattr_tree_set_last_eb_blk,
+       .eo_get_last_eb_blk     = ocfs2_xattr_tree_get_last_eb_blk,
+       .eo_update_clusters     = ocfs2_xattr_tree_update_clusters,
+       .eo_fill_root_el        = ocfs2_xattr_tree_fill_root_el,
+       .eo_fill_max_leaf_clusters = ocfs2_xattr_tree_fill_max_leaf_clusters,
+};
+
+static void ocfs2_dx_root_set_last_eb_blk(struct ocfs2_extent_tree *et,
+                                         u64 blkno)
+{
+       struct ocfs2_dx_root_block *dx_root = et->et_object;
+
+       dx_root->dr_last_eb_blk = cpu_to_le64(blkno);
+}
+
+static u64 ocfs2_dx_root_get_last_eb_blk(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_dx_root_block *dx_root = et->et_object;
+
+       return le64_to_cpu(dx_root->dr_last_eb_blk);
+}
+
+static void ocfs2_dx_root_update_clusters(struct ocfs2_extent_tree *et,
+                                         u32 clusters)
+{
+       struct ocfs2_dx_root_block *dx_root = et->et_object;
+
+       le32_add_cpu(&dx_root->dr_clusters, clusters);
+}
+
+static int ocfs2_dx_root_sanity_check(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_dx_root_block *dx_root = et->et_object;
+
+       BUG_ON(!OCFS2_IS_VALID_DX_ROOT(dx_root));
+
+       return 0;
+}
+
+static void ocfs2_dx_root_fill_root_el(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_dx_root_block *dx_root = et->et_object;
+
+       et->et_root_el = &dx_root->dr_list;
+}
+
+static struct ocfs2_extent_tree_operations ocfs2_dx_root_et_ops = {
+       .eo_set_last_eb_blk     = ocfs2_dx_root_set_last_eb_blk,
+       .eo_get_last_eb_blk     = ocfs2_dx_root_get_last_eb_blk,
+       .eo_update_clusters     = ocfs2_dx_root_update_clusters,
+       .eo_sanity_check        = ocfs2_dx_root_sanity_check,
+       .eo_fill_root_el        = ocfs2_dx_root_fill_root_el,
 };
 
-#define OCFS2_MAX_PATH_DEPTH   5
+static void ocfs2_refcount_tree_fill_root_el(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_refcount_block *rb = et->et_object;
+
+       et->et_root_el = &rb->rf_list;
+}
+
+static void ocfs2_refcount_tree_set_last_eb_blk(struct ocfs2_extent_tree *et,
+                                               u64 blkno)
+{
+       struct ocfs2_refcount_block *rb = et->et_object;
+
+       rb->rf_last_eb_blk = cpu_to_le64(blkno);
+}
+
+static u64 ocfs2_refcount_tree_get_last_eb_blk(struct ocfs2_extent_tree *et)
+{
+       struct ocfs2_refcount_block *rb = et->et_object;
+
+       return le64_to_cpu(rb->rf_last_eb_blk);
+}
+
+static void ocfs2_refcount_tree_update_clusters(struct ocfs2_extent_tree *et,
+                                               u32 clusters)
+{
+       struct ocfs2_refcount_block *rb = et->et_object;
+
+       le32_add_cpu(&rb->rf_clusters, clusters);
+}
+
+static enum ocfs2_contig_type
+ocfs2_refcount_tree_extent_contig(struct ocfs2_extent_tree *et,
+                                 struct ocfs2_extent_rec *ext,
+                                 struct ocfs2_extent_rec *insert_rec)
+{
+       return CONTIG_NONE;
+}
 
-struct ocfs2_path {
-       int                     p_tree_depth;
-       struct ocfs2_path_item  p_node[OCFS2_MAX_PATH_DEPTH];
+static struct ocfs2_extent_tree_operations ocfs2_refcount_tree_et_ops = {
+       .eo_set_last_eb_blk     = ocfs2_refcount_tree_set_last_eb_blk,
+       .eo_get_last_eb_blk     = ocfs2_refcount_tree_get_last_eb_blk,
+       .eo_update_clusters     = ocfs2_refcount_tree_update_clusters,
+       .eo_fill_root_el        = ocfs2_refcount_tree_fill_root_el,
+       .eo_extent_contig       = ocfs2_refcount_tree_extent_contig,
 };
 
-#define path_root_bh(_path) ((_path)->p_node[0].bh)
-#define path_root_el(_path) ((_path)->p_node[0].el)
-#define path_leaf_bh(_path) ((_path)->p_node[(_path)->p_tree_depth].bh)
-#define path_leaf_el(_path) ((_path)->p_node[(_path)->p_tree_depth].el)
-#define path_num_items(_path) ((_path)->p_tree_depth + 1)
+static void __ocfs2_init_extent_tree(struct ocfs2_extent_tree *et,
+                                    struct ocfs2_caching_info *ci,
+                                    struct buffer_head *bh,
+                                    ocfs2_journal_access_func access,
+                                    void *obj,
+                                    struct ocfs2_extent_tree_operations *ops)
+{
+       et->et_ops = ops;
+       et->et_root_bh = bh;
+       et->et_ci = ci;
+       et->et_root_journal_access = access;
+       if (!obj)
+               obj = (void *)bh->b_data;
+       et->et_object = obj;
+
+       et->et_ops->eo_fill_root_el(et);
+       if (!et->et_ops->eo_fill_max_leaf_clusters)
+               et->et_max_leaf_clusters = 0;
+       else
+               et->et_ops->eo_fill_max_leaf_clusters(et);
+}
+
+void ocfs2_init_dinode_extent_tree(struct ocfs2_extent_tree *et,
+                                  struct ocfs2_caching_info *ci,
+                                  struct buffer_head *bh)
+{
+       __ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_di,
+                                NULL, &ocfs2_dinode_et_ops);
+}
+
+void ocfs2_init_xattr_tree_extent_tree(struct ocfs2_extent_tree *et,
+                                      struct ocfs2_caching_info *ci,
+                                      struct buffer_head *bh)
+{
+       __ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_xb,
+                                NULL, &ocfs2_xattr_tree_et_ops);
+}
+
+void ocfs2_init_xattr_value_extent_tree(struct ocfs2_extent_tree *et,
+                                       struct ocfs2_caching_info *ci,
+                                       struct ocfs2_xattr_value_buf *vb)
+{
+       __ocfs2_init_extent_tree(et, ci, vb->vb_bh, vb->vb_access, vb,
+                                &ocfs2_xattr_value_et_ops);
+}
+
+void ocfs2_init_dx_root_extent_tree(struct ocfs2_extent_tree *et,
+                                   struct ocfs2_caching_info *ci,
+                                   struct buffer_head *bh)
+{
+       __ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_dr,
+                                NULL, &ocfs2_dx_root_et_ops);
+}
+
+void ocfs2_init_refcount_extent_tree(struct ocfs2_extent_tree *et,
+                                    struct ocfs2_caching_info *ci,
+                                    struct buffer_head *bh)
+{
+       __ocfs2_init_extent_tree(et, ci, bh, ocfs2_journal_access_rb,
+                                NULL, &ocfs2_refcount_tree_et_ops);
+}
+
+static inline void ocfs2_et_set_last_eb_blk(struct ocfs2_extent_tree *et,
+                                           u64 new_last_eb_blk)
+{
+       et->et_ops->eo_set_last_eb_blk(et, new_last_eb_blk);
+}
+
+static inline u64 ocfs2_et_get_last_eb_blk(struct ocfs2_extent_tree *et)
+{
+       return et->et_ops->eo_get_last_eb_blk(et);
+}
+
+static inline void ocfs2_et_update_clusters(struct ocfs2_extent_tree *et,
+                                           u32 clusters)
+{
+       et->et_ops->eo_update_clusters(et, clusters);
+}
+
+static inline void ocfs2_et_extent_map_insert(struct ocfs2_extent_tree *et,
+                                             struct ocfs2_extent_rec *rec)
+{
+       if (et->et_ops->eo_extent_map_insert)
+               et->et_ops->eo_extent_map_insert(et, rec);
+}
+
+static inline void ocfs2_et_extent_map_truncate(struct ocfs2_extent_tree *et,
+                                               u32 clusters)
+{
+       if (et->et_ops->eo_extent_map_truncate)
+               et->et_ops->eo_extent_map_truncate(et, clusters);
+}
+
+static inline int ocfs2_et_root_journal_access(handle_t *handle,
+                                              struct ocfs2_extent_tree *et,
+                                              int type)
+{
+       return et->et_root_journal_access(handle, et->et_ci, et->et_root_bh,
+                                         type);
+}
+
+static inline enum ocfs2_contig_type
+       ocfs2_et_extent_contig(struct ocfs2_extent_tree *et,
+                              struct ocfs2_extent_rec *rec,
+                              struct ocfs2_extent_rec *insert_rec)
+{
+       if (et->et_ops->eo_extent_contig)
+               return et->et_ops->eo_extent_contig(et, rec, insert_rec);
+
+       return ocfs2_extent_rec_contig(
+                               ocfs2_metadata_cache_get_super(et->et_ci),
+                               rec, insert_rec);
+}
+
+static inline int ocfs2_et_insert_check(struct ocfs2_extent_tree *et,
+                                       struct ocfs2_extent_rec *rec)
+{
+       int ret = 0;
+
+       if (et->et_ops->eo_insert_check)
+               ret = et->et_ops->eo_insert_check(et, rec);
+       return ret;
+}
+
+static inline int ocfs2_et_sanity_check(struct ocfs2_extent_tree *et)
+{
+       int ret = 0;
+
+       if (et->et_ops->eo_sanity_check)
+               ret = et->et_ops->eo_sanity_check(et);
+       return ret;
+}
 
+static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc);
+static int ocfs2_cache_extent_block_free(struct ocfs2_cached_dealloc_ctxt *ctxt,
+                                        struct ocfs2_extent_block *eb);
+static void ocfs2_adjust_rightmost_records(handle_t *handle,
+                                          struct ocfs2_extent_tree *et,
+                                          struct ocfs2_path *path,
+                                          struct ocfs2_extent_rec *insert_rec);
 /*
  * Reset the actual path elements so that we can re-use the structure
  * to build another path. Generally, this involves freeing the buffer
  * heads.
  */
-static void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root)
+void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root)
 {
        int i, start = 0, depth = 0;
        struct ocfs2_path_item *node;
@@ -102,11 +600,13 @@ static void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root)
         */
        if (keep_root)
                depth = le16_to_cpu(path_root_el(path)->l_tree_depth);
+       else
+               path_root_access(path) = NULL;
 
        path->p_tree_depth = depth;
 }
 
-static void ocfs2_free_path(struct ocfs2_path *path)
+void ocfs2_free_path(struct ocfs2_path *path)
 {
        if (path) {
                ocfs2_reinit_path(path, 0);
@@ -115,6 +615,32 @@ static void ocfs2_free_path(struct ocfs2_path *path)
 }
 
 /*
+ * All the elements of src into dest. After this call, src could be freed
+ * without affecting dest.
+ *
+ * Both paths should have the same root. Any non-root elements of dest
+ * will be freed.
+ */
+static void ocfs2_cp_path(struct ocfs2_path *dest, struct ocfs2_path *src)
+{
+       int i;
+
+       BUG_ON(path_root_bh(dest) != path_root_bh(src));
+       BUG_ON(path_root_el(dest) != path_root_el(src));
+       BUG_ON(path_root_access(dest) != path_root_access(src));
+
+       ocfs2_reinit_path(dest, 1);
+
+       for(i = 1; i < OCFS2_MAX_PATH_DEPTH; i++) {
+               dest->p_node[i].bh = src->p_node[i].bh;
+               dest->p_node[i].el = src->p_node[i].el;
+
+               if (dest->p_node[i].bh)
+                       get_bh(dest->p_node[i].bh);
+       }
+}
+
+/*
  * Make the *dest path the same as src and re-initialize src path to
  * have a root only.
  */
@@ -123,6 +649,7 @@ static void ocfs2_mv_path(struct ocfs2_path *dest, struct ocfs2_path *src)
        int i;
 
        BUG_ON(path_root_bh(dest) != path_root_bh(src));
+       BUG_ON(path_root_access(dest) != path_root_access(src));
 
        for(i = 1; i < OCFS2_MAX_PATH_DEPTH; i++) {
                brelse(dest->p_node[i].bh);
@@ -158,7 +685,8 @@ static inline void ocfs2_path_insert_eb(struct ocfs2_path *path, int index,
 }
 
 static struct ocfs2_path *ocfs2_new_path(struct buffer_head *root_bh,
-                                        struct ocfs2_extent_list *root_el)
+                                        struct ocfs2_extent_list *root_el,
+                                        ocfs2_journal_access_func access)
 {
        struct ocfs2_path *path;
 
@@ -170,27 +698,54 @@ static struct ocfs2_path *ocfs2_new_path(struct buffer_head *root_bh,
                get_bh(root_bh);
                path_root_bh(path) = root_bh;
                path_root_el(path) = root_el;
+               path_root_access(path) = access;
        }
 
        return path;
 }
 
+struct ocfs2_path *ocfs2_new_path_from_path(struct ocfs2_path *path)
+{
+       return ocfs2_new_path(path_root_bh(path), path_root_el(path),
+                             path_root_access(path));
+}
+
+struct ocfs2_path *ocfs2_new_path_from_et(struct ocfs2_extent_tree *et)
+{
+       return ocfs2_new_path(et->et_root_bh, et->et_root_el,
+                             et->et_root_journal_access);
+}
+
 /*
- * Allocate and initialize a new path based on a disk inode tree.
+ * Journal the buffer at depth idx.  All idx>0 are extent_blocks,
+ * otherwise it's the root_access function.
+ *
+ * I don't like the way this function's name looks next to
+ * ocfs2_journal_access_path(), but I don't have a better one.
  */
-static struct ocfs2_path *ocfs2_new_inode_path(struct buffer_head *di_bh)
+int ocfs2_path_bh_journal_access(handle_t *handle,
+                                struct ocfs2_caching_info *ci,
+                                struct ocfs2_path *path,
+                                int idx)
 {
-       struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
-       struct ocfs2_extent_list *el = &di->id2.i_list;
+       ocfs2_journal_access_func access = path_root_access(path);
+
+       if (!access)
+               access = ocfs2_journal_access;
+
+       if (idx)
+               access = ocfs2_journal_access_eb;
 
-       return ocfs2_new_path(di_bh, el);
+       return access(handle, ci, path->p_node[idx].bh,
+                     OCFS2_JOURNAL_ACCESS_WRITE);
 }
 
 /*
  * Convenience function to journal all components in a path.
  */
-static int ocfs2_journal_access_path(struct inode *inode, handle_t *handle,
-                                    struct ocfs2_path *path)
+int ocfs2_journal_access_path(struct ocfs2_caching_info *ci,
+                             handle_t *handle,
+                             struct ocfs2_path *path)
 {
        int i, ret = 0;
 
@@ -198,8 +753,7 @@ static int ocfs2_journal_access_path(struct inode *inode, handle_t *handle,
                goto out;
 
        for(i = 0; i < path_num_items(path); i++) {
-               ret = ocfs2_journal_access(handle, inode, path->p_node[i].bh,
-                                          OCFS2_JOURNAL_ACCESS_WRITE);
+               ret = ocfs2_path_bh_journal_access(handle, ci, path, i);
                if (ret < 0) {
                        mlog_errno(ret);
                        goto out;
@@ -210,42 +764,85 @@ out:
        return ret;
 }
 
-enum ocfs2_contig_type {
-       CONTIG_NONE = 0,
-       CONTIG_LEFT,
-       CONTIG_RIGHT
-};
-
-static int ocfs2_block_extent_contig(struct super_block *sb,
-                                    struct ocfs2_extent_rec *ext,
-                                    u64 blkno)
+/*
+ * Return the index of the extent record which contains cluster #v_cluster.
+ * -1 is returned if it was not found.
+ *
+ * Should work fine on interior and exterior nodes.
+ */
+int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster)
 {
-       return blkno == (le64_to_cpu(ext->e_blkno) +
-                        ocfs2_clusters_to_blocks(sb,
-                                                 le32_to_cpu(ext->e_clusters)));
+       int ret = -1;
+       int i;
+       struct ocfs2_extent_rec *rec;
+       u32 rec_end, rec_start, clusters;
+
+       for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
+               rec = &el->l_recs[i];
+
+               rec_start = le32_to_cpu(rec->e_cpos);
+               clusters = ocfs2_rec_clusters(el, rec);
+
+               rec_end = rec_start + clusters;
+
+               if (v_cluster >= rec_start && v_cluster < rec_end) {
+                       ret = i;
+                       break;
+               }
+       }
+
+       return ret;
+}
+
+/*
+ * NOTE: ocfs2_block_extent_contig(), ocfs2_extents_adjacent() and
+ * ocfs2_extent_rec_contig only work properly against leaf nodes!
+ */
+static int ocfs2_block_extent_contig(struct super_block *sb,
+                                    struct ocfs2_extent_rec *ext,
+                                    u64 blkno)
+{
+       u64 blk_end = le64_to_cpu(ext->e_blkno);
+
+       blk_end += ocfs2_clusters_to_blocks(sb,
+                                   le16_to_cpu(ext->e_leaf_clusters));
+
+       return blkno == blk_end;
 }
 
 static int ocfs2_extents_adjacent(struct ocfs2_extent_rec *left,
                                  struct ocfs2_extent_rec *right)
 {
-       return (le32_to_cpu(left->e_cpos) + le32_to_cpu(left->e_clusters) ==
-               le32_to_cpu(right->e_cpos));
+       u32 left_range;
+
+       left_range = le32_to_cpu(left->e_cpos) +
+               le16_to_cpu(left->e_leaf_clusters);
+
+       return (left_range == le32_to_cpu(right->e_cpos));
 }
 
 static enum ocfs2_contig_type
-       ocfs2_extent_contig(struct inode *inode,
-                           struct ocfs2_extent_rec *ext,
-                           struct ocfs2_extent_rec *insert_rec)
+       ocfs2_extent_rec_contig(struct super_block *sb,
+                               struct ocfs2_extent_rec *ext,
+                               struct ocfs2_extent_rec *insert_rec)
 {
        u64 blkno = le64_to_cpu(insert_rec->e_blkno);
 
+       /*
+        * Refuse to coalesce extent records with different flag
+        * fields - we don't want to mix unwritten extents with user
+        * data.
+        */
+       if (ext->e_flags != insert_rec->e_flags)
+               return CONTIG_NONE;
+
        if (ocfs2_extents_adjacent(ext, insert_rec) &&
-           ocfs2_block_extent_contig(inode->i_sb, ext, blkno))
+           ocfs2_block_extent_contig(sb, ext, blkno))
                        return CONTIG_RIGHT;
 
        blkno = le64_to_cpu(ext->e_blkno);
        if (ocfs2_extents_adjacent(insert_rec, ext) &&
-           ocfs2_block_extent_contig(inode->i_sb, insert_rec, blkno))
+           ocfs2_block_extent_contig(sb, insert_rec, blkno))
                return CONTIG_LEFT;
 
        return CONTIG_NONE;
@@ -263,52 +860,133 @@ enum ocfs2_append_type {
        APPEND_TAIL,
 };
 
+enum ocfs2_split_type {
+       SPLIT_NONE = 0,
+       SPLIT_LEFT,
+       SPLIT_RIGHT,
+};
+
 struct ocfs2_insert_type {
+       enum ocfs2_split_type   ins_split;
        enum ocfs2_append_type  ins_appending;
        enum ocfs2_contig_type  ins_contig;
        int                     ins_contig_index;
-       int                     ins_free_records;
        int                     ins_tree_depth;
 };
 
+struct ocfs2_merge_ctxt {
+       enum ocfs2_contig_type  c_contig_type;
+       int                     c_has_empty_extent;
+       int                     c_split_covers_rec;
+};
+
+static int ocfs2_validate_extent_block(struct super_block *sb,
+                                      struct buffer_head *bh)
+{
+       int rc;
+       struct ocfs2_extent_block *eb =
+               (struct ocfs2_extent_block *)bh->b_data;
+
+       mlog(0, "Validating extent block %llu\n",
+            (unsigned long long)bh->b_blocknr);
+
+       BUG_ON(!buffer_uptodate(bh));
+
+       /*
+        * If the ecc fails, we return the error but otherwise
+        * leave the filesystem running.  We know any error is
+        * local to this block.
+        */
+       rc = ocfs2_validate_meta_ecc(sb, bh->b_data, &eb->h_check);
+       if (rc) {
+               mlog(ML_ERROR, "Checksum failed for extent block %llu\n",
+                    (unsigned long long)bh->b_blocknr);
+               return rc;
+       }
+
+       /*
+        * Errors after here are fatal.
+        */
+
+       if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+               ocfs2_error(sb,
+                           "Extent block #%llu has bad signature %.*s",
+                           (unsigned long long)bh->b_blocknr, 7,
+                           eb->h_signature);
+               return -EINVAL;
+       }
+
+       if (le64_to_cpu(eb->h_blkno) != bh->b_blocknr) {
+               ocfs2_error(sb,
+                           "Extent block #%llu has an invalid h_blkno "
+                           "of %llu",
+                           (unsigned long long)bh->b_blocknr,
+                           (unsigned long long)le64_to_cpu(eb->h_blkno));
+               return -EINVAL;
+       }
+
+       if (le32_to_cpu(eb->h_fs_generation) != OCFS2_SB(sb)->fs_generation) {
+               ocfs2_error(sb,
+                           "Extent block #%llu has an invalid "
+                           "h_fs_generation of #%u",
+                           (unsigned long long)bh->b_blocknr,
+                           le32_to_cpu(eb->h_fs_generation));
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+int ocfs2_read_extent_block(struct ocfs2_caching_info *ci, u64 eb_blkno,
+                           struct buffer_head **bh)
+{
+       int rc;
+       struct buffer_head *tmp = *bh;
+
+       rc = ocfs2_read_block(ci, eb_blkno, &tmp,
+                             ocfs2_validate_extent_block);
+
+       /* If ocfs2_read_block() got us a new bh, pass it up. */
+       if (!rc && !*bh)
+               *bh = tmp;
+
+       return rc;
+}
+
+
 /*
  * How many free extents have we got before we need more meta data?
  */
 int ocfs2_num_free_extents(struct ocfs2_super *osb,
-                          struct inode *inode,
-                          struct ocfs2_dinode *fe)
+                          struct ocfs2_extent_tree *et)
 {
        int retval;
-       struct ocfs2_extent_list *el;
+       struct ocfs2_extent_list *el = NULL;
        struct ocfs2_extent_block *eb;
        struct buffer_head *eb_bh = NULL;
+       u64 last_eb_blk = 0;
 
        mlog_entry_void();
 
-       if (!OCFS2_IS_VALID_DINODE(fe)) {
-               OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
-               retval = -EIO;
-               goto bail;
-       }
+       el = et->et_root_el;
+       last_eb_blk = ocfs2_et_get_last_eb_blk(et);
 
-       if (fe->i_last_eb_blk) {
-               retval = ocfs2_read_block(osb, le64_to_cpu(fe->i_last_eb_blk),
-                                         &eb_bh, OCFS2_BH_CACHED, inode);
+       if (last_eb_blk) {
+               retval = ocfs2_read_extent_block(et->et_ci, last_eb_blk,
+                                                &eb_bh);
                if (retval < 0) {
                        mlog_errno(retval);
                        goto bail;
                }
                eb = (struct ocfs2_extent_block *) eb_bh->b_data;
                el = &eb->h_list;
-       } else
-               el = &fe->id2.i_list;
+       }
 
        BUG_ON(el->l_tree_depth != 0);
 
        retval = le16_to_cpu(el->l_count) - le16_to_cpu(el->l_next_free_rec);
 bail:
-       if (eb_bh)
-               brelse(eb_bh);
+       brelse(eb_bh);
 
        mlog_exit(retval);
        return retval;
@@ -319,9 +997,8 @@ bail:
  * sets h_signature, h_blkno, h_suballoc_bit, h_suballoc_slot, and
  * l_count for you
  */
-static int ocfs2_create_new_meta_bhs(struct ocfs2_super *osb,
-                                    handle_t *handle,
-                                    struct inode *inode,
+static int ocfs2_create_new_meta_bhs(handle_t *handle,
+                                    struct ocfs2_extent_tree *et,
                                     int wanted,
                                     struct ocfs2_alloc_context *meta_ac,
                                     struct buffer_head *bhs[])
@@ -330,6 +1007,8 @@ static int ocfs2_create_new_meta_bhs(struct ocfs2_super *osb,
        u16 suballoc_bit_start;
        u32 num_got;
        u64 first_blkno;
+       struct ocfs2_super *osb =
+               OCFS2_SB(ocfs2_metadata_cache_get_super(et->et_ci));
        struct ocfs2_extent_block *eb;
 
        mlog_entry_void();
@@ -355,10 +1034,11 @@ static int ocfs2_create_new_meta_bhs(struct ocfs2_super *osb,
                                mlog_errno(status);
                                goto bail;
                        }
-                       ocfs2_set_new_buffer_uptodate(inode, bhs[i]);
+                       ocfs2_set_new_buffer_uptodate(et->et_ci, bhs[i]);
 
-                       status = ocfs2_journal_access(handle, inode, bhs[i],
-                                                     OCFS2_JOURNAL_ACCESS_CREATE);
+                       status = ocfs2_journal_access_eb(handle, et->et_ci,
+                                                        bhs[i],
+                                                        OCFS2_JOURNAL_ACCESS_CREATE);
                        if (status < 0) {
                                mlog_errno(status);
                                goto bail;
@@ -370,13 +1050,7 @@ static int ocfs2_create_new_meta_bhs(struct ocfs2_super *osb,
                        strcpy(eb->h_signature, OCFS2_EXTENT_BLOCK_SIGNATURE);
                        eb->h_blkno = cpu_to_le64(first_blkno);
                        eb->h_fs_generation = cpu_to_le32(osb->fs_generation);
-
-#ifndef OCFS2_USE_ALL_METADATA_SUBALLOCATORS
-                       /* we always use slot zero's suballocator */
-                       eb->h_suballoc_slot = 0;
-#else
                        eb->h_suballoc_slot = cpu_to_le16(osb->slot_num);
-#endif
                        eb->h_suballoc_bit = cpu_to_le16(suballoc_bit_start);
                        eb->h_list.l_count =
                                cpu_to_le16(ocfs2_extent_recs_per_eb(osb->sb));
@@ -400,8 +1074,7 @@ static int ocfs2_create_new_meta_bhs(struct ocfs2_super *osb,
 bail:
        if (status < 0) {
                for(i = 0; i < wanted; i++) {
-                       if (bhs[i])
-                               brelse(bhs[i]);
+                       brelse(bhs[i]);
                        bhs[i] = NULL;
                }
        }
@@ -428,55 +1101,118 @@ static inline u32 ocfs2_sum_rightmost_rec(struct ocfs2_extent_list  *el)
        i = le16_to_cpu(el->l_next_free_rec) - 1;
 
        return le32_to_cpu(el->l_recs[i].e_cpos) +
-               le32_to_cpu(el->l_recs[i].e_clusters);
+               ocfs2_rec_clusters(el, &el->l_recs[i]);
+}
+
+/*
+ * Change range of the branches in the right most path according to the leaf
+ * extent block's rightmost record.
+ */
+static int ocfs2_adjust_rightmost_branch(handle_t *handle,
+                                        struct ocfs2_extent_tree *et)
+{
+       int status;
+       struct ocfs2_path *path = NULL;
+       struct ocfs2_extent_list *el;
+       struct ocfs2_extent_rec *rec;
+
+       path = ocfs2_new_path_from_et(et);
+       if (!path) {
+               status = -ENOMEM;
+               return status;
+       }
+
+       status = ocfs2_find_path(et->et_ci, path, UINT_MAX);
+       if (status < 0) {
+               mlog_errno(status);
+               goto out;
+       }
+
+       status = ocfs2_extend_trans(handle, path_num_items(path) +
+                                   handle->h_buffer_credits);
+       if (status < 0) {
+               mlog_errno(status);
+               goto out;
+       }
+
+       status = ocfs2_journal_access_path(et->et_ci, handle, path);
+       if (status < 0) {
+               mlog_errno(status);
+               goto out;
+       }
+
+       el = path_leaf_el(path);
+       rec = &el->l_recs[le32_to_cpu(el->l_next_free_rec) - 1];
+
+       ocfs2_adjust_rightmost_records(handle, et, path, rec);
+
+out:
+       ocfs2_free_path(path);
+       return status;
 }
 
 /*
  * Add an entire tree branch to our inode. eb_bh is the extent block
- * to start at, if we don't want to start the branch at the dinode
+ * to start at, if we don't want to start the branch at the root
  * structure.
  *
  * last_eb_bh is required as we have to update it's next_leaf pointer
  * for the new last extent block.
  *
  * the new branch will be 'empty' in the sense that every block will
- * contain a single record with e_clusters == 0.
+ * contain a single record with cluster count == 0.
  */
-static int ocfs2_add_branch(struct ocfs2_super *osb,
-                           handle_t *handle,
-                           struct inode *inode,
-                           struct buffer_head *fe_bh,
+static int ocfs2_add_branch(handle_t *handle,
+                           struct ocfs2_extent_tree *et,
                            struct buffer_head *eb_bh,
-                           struct buffer_head *last_eb_bh,
+                           struct buffer_head **last_eb_bh,
                            struct ocfs2_alloc_context *meta_ac)
 {
        int status, new_blocks, i;
        u64 next_blkno, new_last_eb_blk;
        struct buffer_head *bh;
        struct buffer_head **new_eb_bhs = NULL;
-       struct ocfs2_dinode *fe;
        struct ocfs2_extent_block *eb;
        struct ocfs2_extent_list  *eb_el;
        struct ocfs2_extent_list  *el;
-       u32 new_cpos;
+       u32 new_cpos, root_end;
 
        mlog_entry_void();
 
-       BUG_ON(!last_eb_bh);
-
-       fe = (struct ocfs2_dinode *) fe_bh->b_data;
+       BUG_ON(!last_eb_bh || !*last_eb_bh);
 
        if (eb_bh) {
                eb = (struct ocfs2_extent_block *) eb_bh->b_data;
                el = &eb->h_list;
        } else
-               el = &fe->id2.i_list;
+               el = et->et_root_el;
 
        /* we never add a branch to a leaf. */
        BUG_ON(!el->l_tree_depth);
 
        new_blocks = le16_to_cpu(el->l_tree_depth);
 
+       eb = (struct ocfs2_extent_block *)(*last_eb_bh)->b_data;
+       new_cpos = ocfs2_sum_rightmost_rec(&eb->h_list);
+       root_end = ocfs2_sum_rightmost_rec(et->et_root_el);
+
+       /*
+        * If there is a gap before the root end and the real end
+        * of the righmost leaf block, we need to remove the gap
+        * between new_cpos and root_end first so that the tree
+        * is consistent after we add a new branch(it will start
+        * from new_cpos).
+        */
+       if (root_end > new_cpos) {
+               mlog(0, "adjust the cluster end from %u to %u\n",
+                    root_end, new_cpos);
+               status = ocfs2_adjust_rightmost_branch(handle, et);
+               if (status) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+       }
+
        /* allocate the number of new eb blocks we need */
        new_eb_bhs = kcalloc(new_blocks, sizeof(struct buffer_head *),
                             GFP_KERNEL);
@@ -486,16 +1222,13 @@ static int ocfs2_add_branch(struct ocfs2_super *osb,
                goto bail;
        }
 
-       status = ocfs2_create_new_meta_bhs(osb, handle, inode, new_blocks,
+       status = ocfs2_create_new_meta_bhs(handle, et, new_blocks,
                                           meta_ac, new_eb_bhs);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
 
-       eb = (struct ocfs2_extent_block *)last_eb_bh->b_data;
-       new_cpos = ocfs2_sum_rightmost_rec(&eb->h_list);
-
        /* Note: new_eb_bhs[new_blocks - 1] is the guy which will be
         * linked with the rest of the tree.
         * conversly, new_eb_bhs[0] is the new bottommost leaf.
@@ -507,15 +1240,12 @@ static int ocfs2_add_branch(struct ocfs2_super *osb,
        for(i = 0; i < new_blocks; i++) {
                bh = new_eb_bhs[i];
                eb = (struct ocfs2_extent_block *) bh->b_data;
-               if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
-                       OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
-                       status = -EIO;
-                       goto bail;
-               }
+               /* ocfs2_create_new_meta_bhs() should create it right! */
+               BUG_ON(!OCFS2_IS_VALID_EXTENT_BLOCK(eb));
                eb_el = &eb->h_list;
 
-               status = ocfs2_journal_access(handle, inode, bh,
-                                             OCFS2_JOURNAL_ACCESS_CREATE);
+               status = ocfs2_journal_access_eb(handle, et->et_ci, bh,
+                                                OCFS2_JOURNAL_ACCESS_CREATE);
                if (status < 0) {
                        mlog_errno(status);
                        goto bail;
@@ -530,7 +1260,12 @@ static int ocfs2_add_branch(struct ocfs2_super *osb,
                 */
                eb_el->l_recs[0].e_cpos = cpu_to_le32(new_cpos);
                eb_el->l_recs[0].e_blkno = cpu_to_le64(next_blkno);
-               eb_el->l_recs[0].e_clusters = cpu_to_le32(0);
+               /*
+                * eb_el isn't always an interior node, but even leaf
+                * nodes want a zero'd flags and reserved field so
+                * this gets the whole 32 bits regardless of use.
+                */
+               eb_el->l_recs[0].e_int_clusters = cpu_to_le32(0);
                if (!eb_el->l_tree_depth)
                        new_last_eb_blk = le64_to_cpu(eb->h_blkno);
 
@@ -549,21 +1284,21 @@ static int ocfs2_add_branch(struct ocfs2_super *osb,
         * journal_dirty erroring as it won't unless we've aborted the
         * handle (in which case we would never be here) so reserving
         * the write with journal_access is all we need to do. */
-       status = ocfs2_journal_access(handle, inode, last_eb_bh,
-                                     OCFS2_JOURNAL_ACCESS_WRITE);
+       status = ocfs2_journal_access_eb(handle, et->et_ci, *last_eb_bh,
+                                        OCFS2_JOURNAL_ACCESS_WRITE);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
-       status = ocfs2_journal_access(handle, inode, fe_bh,
-                                     OCFS2_JOURNAL_ACCESS_WRITE);
+       status = ocfs2_et_root_journal_access(handle, et,
+                                             OCFS2_JOURNAL_ACCESS_WRITE);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
        if (eb_bh) {
-               status = ocfs2_journal_access(handle, inode, eb_bh,
-                                             OCFS2_JOURNAL_ACCESS_WRITE);
+               status = ocfs2_journal_access_eb(handle, et->et_ci, eb_bh,
+                                                OCFS2_JOURNAL_ACCESS_WRITE);
                if (status < 0) {
                        mlog_errno(status);
                        goto bail;
@@ -571,24 +1306,24 @@ static int ocfs2_add_branch(struct ocfs2_super *osb,
        }
 
        /* Link the new branch into the rest of the tree (el will
-        * either be on the fe, or the extent block passed in. */
+        * either be on the root_bh, or the extent block passed in. */
        i = le16_to_cpu(el->l_next_free_rec);
        el->l_recs[i].e_blkno = cpu_to_le64(next_blkno);
        el->l_recs[i].e_cpos = cpu_to_le32(new_cpos);
-       el->l_recs[i].e_clusters = 0;
+       el->l_recs[i].e_int_clusters = 0;
        le16_add_cpu(&el->l_next_free_rec, 1);
 
        /* fe needs a new last extent block pointer, as does the
         * next_leaf on the previously last-extent-block. */
-       fe->i_last_eb_blk = cpu_to_le64(new_last_eb_blk);
+       ocfs2_et_set_last_eb_blk(et, new_last_eb_blk);
 
-       eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+       eb = (struct ocfs2_extent_block *) (*last_eb_bh)->b_data;
        eb->h_next_leaf_blk = cpu_to_le64(new_last_eb_blk);
 
-       status = ocfs2_journal_dirty(handle, last_eb_bh);
+       status = ocfs2_journal_dirty(handle, *last_eb_bh);
        if (status < 0)
                mlog_errno(status);
-       status = ocfs2_journal_dirty(handle, fe_bh);
+       status = ocfs2_journal_dirty(handle, et->et_root_bh);
        if (status < 0)
                mlog_errno(status);
        if (eb_bh) {
@@ -597,12 +1332,19 @@ static int ocfs2_add_branch(struct ocfs2_super *osb,
                        mlog_errno(status);
        }
 
+       /*
+        * Some callers want to track the rightmost leaf so pass it
+        * back here.
+        */
+       brelse(*last_eb_bh);
+       get_bh(new_eb_bhs[0]);
+       *last_eb_bh = new_eb_bhs[0];
+
        status = 0;
 bail:
        if (new_eb_bhs) {
                for (i = 0; i < new_blocks; i++)
-                       if (new_eb_bhs[i])
-                               brelse(new_eb_bhs[i]);
+                       brelse(new_eb_bhs[i]);
                kfree(new_eb_bhs);
        }
 
@@ -615,24 +1357,21 @@ bail:
  * returns back the new extent block so you can add a branch to it
  * after this call.
  */
-static int ocfs2_shift_tree_depth(struct ocfs2_super *osb,
-                                 handle_t *handle,
-                                 struct inode *inode,
-                                 struct buffer_head *fe_bh,
+static int ocfs2_shift_tree_depth(handle_t *handle,
+                                 struct ocfs2_extent_tree *et,
                                  struct ocfs2_alloc_context *meta_ac,
                                  struct buffer_head **ret_new_eb_bh)
 {
        int status, i;
        u32 new_clusters;
        struct buffer_head *new_eb_bh = NULL;
-       struct ocfs2_dinode *fe;
        struct ocfs2_extent_block *eb;
-       struct ocfs2_extent_list  *fe_el;
+       struct ocfs2_extent_list  *root_el;
        struct ocfs2_extent_list  *eb_el;
 
        mlog_entry_void();
 
-       status = ocfs2_create_new_meta_bhs(osb, handle, inode, 1, meta_ac,
+       status = ocfs2_create_new_meta_bhs(handle, et, 1, meta_ac,
                                           &new_eb_bh);
        if (status < 0) {
                mlog_errno(status);
@@ -640,31 +1379,24 @@ static int ocfs2_shift_tree_depth(struct ocfs2_super *osb,
        }
 
        eb = (struct ocfs2_extent_block *) new_eb_bh->b_data;
-       if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
-               OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
-               status = -EIO;
-               goto bail;
-       }
+       /* ocfs2_create_new_meta_bhs() should create it right! */
+       BUG_ON(!OCFS2_IS_VALID_EXTENT_BLOCK(eb));
 
        eb_el = &eb->h_list;
-       fe = (struct ocfs2_dinode *) fe_bh->b_data;
-       fe_el = &fe->id2.i_list;
+       root_el = et->et_root_el;
 
-       status = ocfs2_journal_access(handle, inode, new_eb_bh,
-                                     OCFS2_JOURNAL_ACCESS_CREATE);
+       status = ocfs2_journal_access_eb(handle, et->et_ci, new_eb_bh,
+                                        OCFS2_JOURNAL_ACCESS_CREATE);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
 
-       /* copy the fe data into the new extent block */
-       eb_el->l_tree_depth = fe_el->l_tree_depth;
-       eb_el->l_next_free_rec = fe_el->l_next_free_rec;
-       for(i = 0; i < le16_to_cpu(fe_el->l_next_free_rec); i++) {
-               eb_el->l_recs[i].e_cpos = fe_el->l_recs[i].e_cpos;
-               eb_el->l_recs[i].e_clusters = fe_el->l_recs[i].e_clusters;
-               eb_el->l_recs[i].e_blkno = fe_el->l_recs[i].e_blkno;
-       }
+       /* copy the root extent list data into the new extent block */
+       eb_el->l_tree_depth = root_el->l_tree_depth;
+       eb_el->l_next_free_rec = root_el->l_next_free_rec;
+       for (i = 0; i < le16_to_cpu(root_el->l_next_free_rec); i++)
+               eb_el->l_recs[i] = root_el->l_recs[i];
 
        status = ocfs2_journal_dirty(handle, new_eb_bh);
        if (status < 0) {
@@ -672,8 +1404,8 @@ static int ocfs2_shift_tree_depth(struct ocfs2_super *osb,
                goto bail;
        }
 
-       status = ocfs2_journal_access(handle, inode, fe_bh,
-                                     OCFS2_JOURNAL_ACCESS_WRITE);
+       status = ocfs2_et_root_journal_access(handle, et,
+                                             OCFS2_JOURNAL_ACCESS_WRITE);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
@@ -681,24 +1413,21 @@ static int ocfs2_shift_tree_depth(struct ocfs2_super *osb,
 
        new_clusters = ocfs2_sum_rightmost_rec(eb_el);
 
-       /* update fe now */
-       le16_add_cpu(&fe_el->l_tree_depth, 1);
-       fe_el->l_recs[0].e_cpos = 0;
-       fe_el->l_recs[0].e_blkno = eb->h_blkno;
-       fe_el->l_recs[0].e_clusters = cpu_to_le32(new_clusters);
-       for(i = 1; i < le16_to_cpu(fe_el->l_next_free_rec); i++) {
-               fe_el->l_recs[i].e_cpos = 0;
-               fe_el->l_recs[i].e_clusters = 0;
-               fe_el->l_recs[i].e_blkno = 0;
-       }
-       fe_el->l_next_free_rec = cpu_to_le16(1);
+       /* update root_bh now */
+       le16_add_cpu(&root_el->l_tree_depth, 1);
+       root_el->l_recs[0].e_cpos = 0;
+       root_el->l_recs[0].e_blkno = eb->h_blkno;
+       root_el->l_recs[0].e_int_clusters = cpu_to_le32(new_clusters);
+       for (i = 1; i < le16_to_cpu(root_el->l_next_free_rec); i++)
+               memset(&root_el->l_recs[i], 0, sizeof(struct ocfs2_extent_rec));
+       root_el->l_next_free_rec = cpu_to_le16(1);
 
        /* If this is our 1st tree depth shift, then last_eb_blk
         * becomes the allocated extent block */
-       if (fe_el->l_tree_depth == cpu_to_le16(1))
-               fe->i_last_eb_blk = eb->h_blkno;
+       if (root_el->l_tree_depth == cpu_to_le16(1))
+               ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));
 
-       status = ocfs2_journal_dirty(handle, fe_bh);
+       status = ocfs2_journal_dirty(handle, et->et_root_bh);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
@@ -708,8 +1437,7 @@ static int ocfs2_shift_tree_depth(struct ocfs2_super *osb,
        new_eb_bh = NULL;
        status = 0;
 bail:
-       if (new_eb_bh)
-               brelse(new_eb_bh);
+       brelse(new_eb_bh);
 
        mlog_exit(status);
        return status;
@@ -724,22 +1452,19 @@ bail:
  * 1) a lowest extent block is found, then we pass it back in
  *    *lowest_eb_bh and return '0'
  *
- * 2) the search fails to find anything, but the dinode has room. We
+ * 2) the search fails to find anything, but the root_el has room. We
  *    pass NULL back in *lowest_eb_bh, but still return '0'
  *
- * 3) the search fails to find anything AND the dinode is full, in
+ * 3) the search fails to find anything AND the root_el is full, in
  *    which case we return > 0
  *
  * return status < 0 indicates an error.
  */
-static int ocfs2_find_branch_target(struct ocfs2_super *osb,
-                                   struct inode *inode,
-                                   struct buffer_head *fe_bh,
+static int ocfs2_find_branch_target(struct ocfs2_extent_tree *et,
                                    struct buffer_head **target_bh)
 {
        int status = 0, i;
        u64 blkno;
-       struct ocfs2_dinode *fe;
        struct ocfs2_extent_block *eb;
        struct ocfs2_extent_list  *el;
        struct buffer_head *bh = NULL;
@@ -749,52 +1474,44 @@ static int ocfs2_find_branch_target(struct ocfs2_super *osb,
 
        *target_bh = NULL;
 
-       fe = (struct ocfs2_dinode *) fe_bh->b_data;
-       el = &fe->id2.i_list;
+       el = et->et_root_el;
 
        while(le16_to_cpu(el->l_tree_depth) > 1) {
                if (le16_to_cpu(el->l_next_free_rec) == 0) {
-                       ocfs2_error(inode->i_sb, "Dinode %llu has empty "
+                       ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
+                                   "Owner %llu has empty "
                                    "extent list (next_free_rec == 0)",
-                                   (unsigned long long)OCFS2_I(inode)->ip_blkno);
+                                   (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci));
                        status = -EIO;
                        goto bail;
                }
                i = le16_to_cpu(el->l_next_free_rec) - 1;
                blkno = le64_to_cpu(el->l_recs[i].e_blkno);
                if (!blkno) {
-                       ocfs2_error(inode->i_sb, "Dinode %llu has extent "
+                       ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
+                                   "Owner %llu has extent "
                                    "list where extent # %d has no physical "
                                    "block start",
-                                   (unsigned long long)OCFS2_I(inode)->ip_blkno, i);
+                                   (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci), i);
                        status = -EIO;
                        goto bail;
                }
 
-               if (bh) {
-                       brelse(bh);
-                       bh = NULL;
-               }
+               brelse(bh);
+               bh = NULL;
 
-               status = ocfs2_read_block(osb, blkno, &bh, OCFS2_BH_CACHED,
-                                         inode);
+               status = ocfs2_read_extent_block(et->et_ci, blkno, &bh);
                if (status < 0) {
                        mlog_errno(status);
                        goto bail;
                }
 
                eb = (struct ocfs2_extent_block *) bh->b_data;
-               if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
-                       OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
-                       status = -EIO;
-                       goto bail;
-               }
                el = &eb->h_list;
 
                if (le16_to_cpu(el->l_next_free_rec) <
                    le16_to_cpu(el->l_count)) {
-                       if (lowest_bh)
-                               brelse(lowest_bh);
+                       brelse(lowest_bh);
                        lowest_bh = bh;
                        get_bh(lowest_bh);
                }
@@ -802,22 +1519,94 @@ static int ocfs2_find_branch_target(struct ocfs2_super *osb,
 
        /* If we didn't find one and the fe doesn't have any room,
         * then return '1' */
-       if (!lowest_bh
-           && (fe->id2.i_list.l_next_free_rec == fe->id2.i_list.l_count))
+       el = et->et_root_el;
+       if (!lowest_bh && (el->l_next_free_rec == el->l_count))
                status = 1;
 
        *target_bh = lowest_bh;
 bail:
-       if (bh)
-               brelse(bh);
+       brelse(bh);
 
        mlog_exit(status);
        return status;
 }
 
-static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
+/*
+ * Grow a b-tree so that it has more records.
+ *
+ * We might shift the tree depth in which case existing paths should
+ * be considered invalid.
+ *
+ * Tree depth after the grow is returned via *final_depth.
+ *
+ * *last_eb_bh will be updated by ocfs2_add_branch().
+ */
+static int ocfs2_grow_tree(handle_t *handle, struct ocfs2_extent_tree *et,
+                          int *final_depth, struct buffer_head **last_eb_bh,
+                          struct ocfs2_alloc_context *meta_ac)
 {
-       return !rec->e_clusters;
+       int ret, shift;
+       struct ocfs2_extent_list *el = et->et_root_el;
+       int depth = le16_to_cpu(el->l_tree_depth);
+       struct buffer_head *bh = NULL;
+
+       BUG_ON(meta_ac == NULL);
+
+       shift = ocfs2_find_branch_target(et, &bh);
+       if (shift < 0) {
+               ret = shift;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       /* We traveled all the way to the bottom of the allocation tree
+        * and didn't find room for any more extents - we need to add
+        * another tree level */
+       if (shift) {
+               BUG_ON(bh);
+               mlog(0, "need to shift tree depth (current = %d)\n", depth);
+
+               /* ocfs2_shift_tree_depth will return us a buffer with
+                * the new extent block (so we can pass that to
+                * ocfs2_add_branch). */
+               ret = ocfs2_shift_tree_depth(handle, et, meta_ac, &bh);
+               if (ret < 0) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+               depth++;
+               if (depth == 1) {
+                       /*
+                        * Special case: we have room now if we shifted from
+                        * tree_depth 0, so no more work needs to be done.
+                        *
+                        * We won't be calling add_branch, so pass
+                        * back *last_eb_bh as the new leaf. At depth
+                        * zero, it should always be null so there's
+                        * no reason to brelse.
+                        */
+                       BUG_ON(*last_eb_bh);
+                       get_bh(bh);
+                       *last_eb_bh = bh;
+                       goto out;
+               }
+       }
+
+       /* call ocfs2_add_branch to add the final part of the tree with
+        * the new data. */
+       mlog(0, "add branch. bh = %p\n", bh);
+       ret = ocfs2_add_branch(handle, et, bh, last_eb_bh,
+                              meta_ac);
+       if (ret < 0) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+out:
+       if (final_depth)
+               *final_depth = depth;
+       brelse(bh);
+       return ret;
 }
 
 /*
@@ -851,8 +1640,7 @@ static void ocfs2_rotate_leaf(struct ocfs2_extent_list *el,
        BUG_ON(!next_free);
 
        /* The tree code before us didn't allow enough room in the leaf. */
-       if (el->l_next_free_rec == el->l_count && !has_empty)
-               BUG();
+       BUG_ON(el->l_next_free_rec == el->l_count && !has_empty);
 
        /*
         * The easiest way to approach this is to just remove the
@@ -917,6 +1705,22 @@ static void ocfs2_rotate_leaf(struct ocfs2_extent_list *el,
 
 }
 
+static void ocfs2_remove_empty_extent(struct ocfs2_extent_list *el)
+{
+       int size, num_recs = le16_to_cpu(el->l_next_free_rec);
+
+       BUG_ON(num_recs == 0);
+
+       if (ocfs2_is_empty_extent(&el->l_recs[0])) {
+               num_recs--;
+               size = num_recs * sizeof(struct ocfs2_extent_rec);
+               memmove(&el->l_recs[0], &el->l_recs[1], size);
+               memset(&el->l_recs[num_recs], 0,
+                      sizeof(struct ocfs2_extent_rec));
+               el->l_next_free_rec = cpu_to_le16(num_recs);
+       }
+}
+
 /*
  * Create an empty extent record .
  *
@@ -928,6 +1732,8 @@ static void ocfs2_create_empty_extent(struct ocfs2_extent_list *el)
 {
        int next_free = le16_to_cpu(el->l_next_free_rec);
 
+       BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
+
        if (next_free == 0)
                goto set_and_inc;
 
@@ -959,7 +1765,7 @@ set_and_inc:
  *
  * The array index of the subtree root is passed back.
  */
-static int ocfs2_find_subtree_root(struct inode *inode,
+static int ocfs2_find_subtree_root(struct ocfs2_extent_tree *et,
                                   struct ocfs2_path *left,
                                   struct ocfs2_path *right)
 {
@@ -977,10 +1783,10 @@ static int ocfs2_find_subtree_root(struct inode *inode,
                 * The caller didn't pass two adjacent paths.
                 */
                mlog_bug_on_msg(i > left->p_tree_depth,
-                               "Inode %lu, left depth %u, right depth %u\n"
+                               "Owner %llu, left depth %u, right depth %u\n"
                                "left leaf blk %llu, right leaf blk %llu\n",
-                               inode->i_ino, left->p_tree_depth,
-                               right->p_tree_depth,
+                               (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                               left->p_tree_depth, right->p_tree_depth,
                                (unsigned long long)path_leaf_bh(left)->b_blocknr,
                                (unsigned long long)path_leaf_bh(right)->b_blocknr);
        } while (left->p_node[i].bh->b_blocknr ==
@@ -997,7 +1803,7 @@ typedef void (path_insert_t)(void *, struct buffer_head *);
  * This code can be called with a cpos larger than the tree, in which
  * case it will return the rightmost path.
  */
-static int __ocfs2_find_path(struct inode *inode,
+static int __ocfs2_find_path(struct ocfs2_caching_info *ci,
                             struct ocfs2_extent_list *root_el, u32 cpos,
                             path_insert_t *func, void *data)
 {
@@ -1008,15 +1814,14 @@ static int __ocfs2_find_path(struct inode *inode,
        struct ocfs2_extent_block *eb;
        struct ocfs2_extent_list *el;
        struct ocfs2_extent_rec *rec;
-       struct ocfs2_inode_info *oi = OCFS2_I(inode);
 
        el = root_el;
        while (el->l_tree_depth) {
                if (le16_to_cpu(el->l_next_free_rec) == 0) {
-                       ocfs2_error(inode->i_sb,
-                                   "Inode %llu has empty extent list at "
+                       ocfs2_error(ocfs2_metadata_cache_get_super(ci),
+                                   "Owner %llu has empty extent list at "
                                    "depth %u\n",
-                                   (unsigned long long)oi->ip_blkno,
+                                   (unsigned long long)ocfs2_metadata_cache_owner(ci),
                                    le16_to_cpu(el->l_tree_depth));
                        ret = -EROFS;
                        goto out;
@@ -1032,17 +1837,17 @@ static int __ocfs2_find_path(struct inode *inode,
                         * rightmost record.
                         */
                        range = le32_to_cpu(rec->e_cpos) +
-                               le32_to_cpu(rec->e_clusters);
+                               ocfs2_rec_clusters(el, rec);
                        if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
                            break;
                }
 
                blkno = le64_to_cpu(el->l_recs[i].e_blkno);
                if (blkno == 0) {
-                       ocfs2_error(inode->i_sb,
-                                   "Inode %llu has bad blkno in extent list "
+                       ocfs2_error(ocfs2_metadata_cache_get_super(ci),
+                                   "Owner %llu has bad blkno in extent list "
                                    "at depth %u (index %d)\n",
-                                   (unsigned long long)oi->ip_blkno,
+                                   (unsigned long long)ocfs2_metadata_cache_owner(ci),
                                    le16_to_cpu(el->l_tree_depth), i);
                        ret = -EROFS;
                        goto out;
@@ -1050,8 +1855,7 @@ static int __ocfs2_find_path(struct inode *inode,
 
                brelse(bh);
                bh = NULL;
-               ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno,
-                                      &bh, OCFS2_BH_CACHED, inode);
+               ret = ocfs2_read_extent_block(ci, blkno, &bh);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
@@ -1059,18 +1863,13 @@ static int __ocfs2_find_path(struct inode *inode,
 
                eb = (struct ocfs2_extent_block *) bh->b_data;
                el = &eb->h_list;
-               if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
-                       OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
-                       ret = -EIO;
-                       goto out;
-               }
 
                if (le16_to_cpu(el->l_next_free_rec) >
                    le16_to_cpu(el->l_count)) {
-                       ocfs2_error(inode->i_sb,
-                                   "Inode %llu has bad count in extent list "
+                       ocfs2_error(ocfs2_metadata_cache_get_super(ci),
+                                   "Owner %llu has bad count in extent list "
                                    "at block %llu (next free=%u, count=%u)\n",
-                                   (unsigned long long)oi->ip_blkno,
+                                   (unsigned long long)ocfs2_metadata_cache_owner(ci),
                                    (unsigned long long)bh->b_blocknr,
                                    le16_to_cpu(el->l_next_free_rec),
                                    le16_to_cpu(el->l_count));
@@ -1114,14 +1913,14 @@ static void find_path_ins(void *data, struct buffer_head *bh)
        ocfs2_path_insert_eb(fp->path, fp->index, bh);
        fp->index++;
 }
-static int ocfs2_find_path(struct inode *inode, struct ocfs2_path *path,
-                          u32 cpos)
+int ocfs2_find_path(struct ocfs2_caching_info *ci,
+                   struct ocfs2_path *path, u32 cpos)
 {
        struct find_path_data data;
 
        data.index = 1;
        data.path = path;
-       return __ocfs2_find_path(inode, path_root_el(path), cpos,
+       return __ocfs2_find_path(ci, path_root_el(path), cpos,
                                 find_path_ins, &data);
 }
 
@@ -1146,13 +1945,14 @@ static void find_leaf_ins(void *data, struct buffer_head *bh)
  *
  * This function doesn't handle non btree extent lists.
  */
-int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
-                   u32 cpos, struct buffer_head **leaf_bh)
+int ocfs2_find_leaf(struct ocfs2_caching_info *ci,
+                   struct ocfs2_extent_list *root_el, u32 cpos,
+                   struct buffer_head **leaf_bh)
 {
        int ret;
        struct buffer_head *bh = NULL;
 
-       ret = __ocfs2_find_path(inode, root_el, cpos, find_leaf_ins, &bh);
+       ret = __ocfs2_find_path(ci, root_el, cpos, find_leaf_ins, &bh);
        if (ret) {
                mlog_errno(ret);
                goto out;
@@ -1192,22 +1992,27 @@ static void ocfs2_adjust_adjacent_records(struct ocfs2_extent_rec *left_rec,
         * immediately to their right.
         */
        left_clusters = le32_to_cpu(right_child_el->l_recs[0].e_cpos);
+       if (!ocfs2_rec_clusters(right_child_el, &right_child_el->l_recs[0])) {
+               BUG_ON(right_child_el->l_tree_depth);
+               BUG_ON(le16_to_cpu(right_child_el->l_next_free_rec) <= 1);
+               left_clusters = le32_to_cpu(right_child_el->l_recs[1].e_cpos);
+       }
        left_clusters -= le32_to_cpu(left_rec->e_cpos);
-       left_rec->e_clusters = cpu_to_le32(left_clusters);
+       left_rec->e_int_clusters = cpu_to_le32(left_clusters);
 
        /*
         * Calculate the rightmost cluster count boundary before
-        * moving cpos - we will need to adjust e_clusters after
+        * moving cpos - we will need to adjust clusters after
         * updating e_cpos to keep the same highest cluster count.
         */
        right_end = le32_to_cpu(right_rec->e_cpos);
-       right_end += le32_to_cpu(right_rec->e_clusters);
+       right_end += le32_to_cpu(right_rec->e_int_clusters);
 
        right_rec->e_cpos = left_rec->e_cpos;
        le32_add_cpu(&right_rec->e_cpos, left_clusters);
 
        right_end -= le32_to_cpu(right_rec->e_cpos);
-       right_rec->e_clusters = cpu_to_le32(right_end);
+       right_rec->e_int_clusters = cpu_to_le32(right_end);
 }
 
 /*
@@ -1250,8 +2055,10 @@ static void ocfs2_adjust_root_records(struct ocfs2_extent_list *root_el,
  *   - When our insert into the right path leaf is at the leftmost edge
  *     and requires an update of the path immediately to it's left. This
  *     can occur at the end of some types of rotation and appending inserts.
+ *   - When we've adjusted the last extent record in the left path leaf and the
+ *     1st extent record in the right path leaf during cross extent block merge.
  */
-static void ocfs2_complete_edge_insert(struct inode *inode, handle_t *handle,
+static void ocfs2_complete_edge_insert(handle_t *handle,
                                       struct ocfs2_path *left_path,
                                       struct ocfs2_path *right_path,
                                       int subtree_index)
@@ -1329,8 +2136,8 @@ static void ocfs2_complete_edge_insert(struct inode *inode, handle_t *handle,
                mlog_errno(ret);
 }
 
-static int ocfs2_rotate_subtree_right(struct inode *inode,
-                                     handle_t *handle,
+static int ocfs2_rotate_subtree_right(handle_t *handle,
+                                     struct ocfs2_extent_tree *et,
                                      struct ocfs2_path *left_path,
                                      struct ocfs2_path *right_path,
                                      int subtree_index)
@@ -1346,10 +2153,10 @@ static int ocfs2_rotate_subtree_right(struct inode *inode,
        left_el = path_leaf_el(left_path);
 
        if (left_el->l_next_free_rec != left_el->l_count) {
-               ocfs2_error(inode->i_sb,
+               ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
                            "Inode %llu has non-full interior leaf node %llu"
                            "(next free = %u)",
-                           (unsigned long long)OCFS2_I(inode)->ip_blkno,
+                           (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
                            (unsigned long long)left_leaf_bh->b_blocknr,
                            le16_to_cpu(left_el->l_next_free_rec));
                return -EROFS;
@@ -1365,25 +2172,23 @@ static int ocfs2_rotate_subtree_right(struct inode *inode,
        root_bh = left_path->p_node[subtree_index].bh;
        BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
 
-       ret = ocfs2_journal_access(handle, inode, root_bh,
-                                  OCFS2_JOURNAL_ACCESS_WRITE);
+       ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
+                                          subtree_index);
        if (ret) {
                mlog_errno(ret);
                goto out;
        }
 
        for(i = subtree_index + 1; i < path_num_items(right_path); i++) {
-               ret = ocfs2_journal_access(handle, inode,
-                                          right_path->p_node[i].bh,
-                                          OCFS2_JOURNAL_ACCESS_WRITE);
+               ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                  right_path, i);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
                }
 
-               ret = ocfs2_journal_access(handle, inode,
-                                          left_path->p_node[i].bh,
-                                          OCFS2_JOURNAL_ACCESS_WRITE);
+               ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                  left_path, i);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
@@ -1396,7 +2201,7 @@ static int ocfs2_rotate_subtree_right(struct inode *inode,
        /* This is a code error, not a disk corruption. */
        mlog_bug_on_msg(!right_el->l_next_free_rec, "Inode %llu: Rotate fails "
                        "because rightmost leaf block %llu is empty\n",
-                       (unsigned long long)OCFS2_I(inode)->ip_blkno,
+                       (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
                        (unsigned long long)right_leaf_bh->b_blocknr);
 
        ocfs2_create_empty_extent(right_el);
@@ -1430,8 +2235,8 @@ static int ocfs2_rotate_subtree_right(struct inode *inode,
                goto out;
        }
 
-       ocfs2_complete_edge_insert(inode, handle, left_path, right_path,
-                               subtree_index);
+       ocfs2_complete_edge_insert(handle, left_path, right_path,
+                                  subtree_index);
 
 out:
        return ret;
@@ -1450,6 +2255,8 @@ static int ocfs2_find_cpos_for_left_leaf(struct super_block *sb,
        u64 blkno;
        struct ocfs2_extent_list *el;
 
+       BUG_ON(path->p_tree_depth == 0);
+
        *cpos = 0;
 
        blkno = path_leaf_bh(path)->b_blocknr;
@@ -1484,7 +2291,9 @@ static int ocfs2_find_cpos_for_left_leaf(struct super_block *sb,
                                }
 
                                *cpos = le32_to_cpu(el->l_recs[j - 1].e_cpos);
-                               *cpos = *cpos + le32_to_cpu(el->l_recs[j - 1].e_clusters) - 1;
+                               *cpos = *cpos + ocfs2_rec_clusters(el,
+                                                          &el->l_recs[j - 1]);
+                               *cpos = *cpos - 1;
                                goto out;
                        }
                }
@@ -1508,13 +2317,27 @@ out:
        return ret;
 }
 
+/*
+ * Extend the transaction by enough credits to complete the rotation,
+ * and still leave at least the original number of credits allocated
+ * to this transaction.
+ */
 static int ocfs2_extend_rotate_transaction(handle_t *handle, int subtree_depth,
+                                          int op_credits,
                                           struct ocfs2_path *path)
 {
-       int credits = (path->p_tree_depth - subtree_depth) * 2 + 1;
+       int ret;
+       int credits = (path->p_tree_depth - subtree_depth) * 2 + 1 + op_credits;
+
+       if (handle->h_buffer_credits < credits) {
+               ret = ocfs2_extend_trans(handle,
+                                        credits - handle->h_buffer_credits);
+               if (ret)
+                       return ret;
 
-       if (handle->h_buffer_credits < credits)
-               return ocfs2_extend_trans(handle, credits);
+               if (unlikely(handle->h_buffer_credits < credits))
+                       return ocfs2_extend_trans(handle, credits);
+       }
 
        return 0;
 }
@@ -1545,6 +2368,29 @@ static int ocfs2_rotate_requires_path_adjustment(struct ocfs2_path *left_path,
        return 0;
 }
 
+static int ocfs2_leftmost_rec_contains(struct ocfs2_extent_list *el, u32 cpos)
+{
+       int next_free = le16_to_cpu(el->l_next_free_rec);
+       unsigned int range;
+       struct ocfs2_extent_rec *rec;
+
+       if (next_free == 0)
+               return 0;
+
+       rec = &el->l_recs[0];
+       if (ocfs2_is_empty_extent(rec)) {
+               /* Empty list. */
+               if (next_free == 1)
+                       return 0;
+               rec = &el->l_recs[1];
+       }
+
+       range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
+       if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
+               return 1;
+       return 0;
+}
+
 /*
  * Rotate all the records in a btree right one record, starting at insert_cpos.
  *
@@ -1552,7 +2398,7 @@ static int ocfs2_rotate_requires_path_adjustment(struct ocfs2_path *left_path,
  *
  * The array is assumed to be large enough to hold an entire path (tree depth).
  *
- * Upon succesful return from this function:
+ * Upon successful return from this function:
  *
  * - The 'right_path' array will contain a path to the leaf block
  *   whose range contains e_cpos.
@@ -1561,27 +2407,28 @@ static int ocfs2_rotate_requires_path_adjustment(struct ocfs2_path *left_path,
  *   *ret_left_path will contain a valid path which can be passed to
  *   ocfs2_insert_path().
  */
-static int ocfs2_rotate_tree_right(struct inode *inode,
-                                  handle_t *handle,
+static int ocfs2_rotate_tree_right(handle_t *handle,
+                                  struct ocfs2_extent_tree *et,
+                                  enum ocfs2_split_type split,
                                   u32 insert_cpos,
                                   struct ocfs2_path *right_path,
                                   struct ocfs2_path **ret_left_path)
 {
-       int ret, start;
+       int ret, start, orig_credits = handle->h_buffer_credits;
        u32 cpos;
        struct ocfs2_path *left_path = NULL;
+       struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
 
        *ret_left_path = NULL;
 
-       left_path = ocfs2_new_path(path_root_bh(right_path),
-                                  path_root_el(right_path));
+       left_path = ocfs2_new_path_from_path(right_path);
        if (!left_path) {
                ret = -ENOMEM;
                mlog_errno(ret);
                goto out;
        }
 
-       ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, right_path, &cpos);
+       ret = ocfs2_find_cpos_for_left_leaf(sb, right_path, &cpos);
        if (ret) {
                mlog_errno(ret);
                goto out;
@@ -1619,7 +2466,7 @@ static int ocfs2_rotate_tree_right(struct inode *inode,
                mlog(0, "Rotating a tree: ins. cpos: %u, left path cpos: %u\n",
                     insert_cpos, cpos);
 
-               ret = ocfs2_find_path(inode, left_path, cpos);
+               ret = ocfs2_find_path(et->et_ci, left_path, cpos);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
@@ -1627,16 +2474,17 @@ static int ocfs2_rotate_tree_right(struct inode *inode,
 
                mlog_bug_on_msg(path_leaf_bh(left_path) ==
                                path_leaf_bh(right_path),
-                               "Inode %lu: error during insert of %u "
+                               "Owner %llu: error during insert of %u "
                                "(left path cpos %u) results in two identical "
                                "paths ending at %llu\n",
-                               inode->i_ino, insert_cpos, cpos,
+                               (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                               insert_cpos, cpos,
                                (unsigned long long)
                                path_leaf_bh(left_path)->b_blocknr);
 
-               if (ocfs2_rotate_requires_path_adjustment(left_path,
+               if (split == SPLIT_NONE &&
+                   ocfs2_rotate_requires_path_adjustment(left_path,
                                                          insert_cpos)) {
-                       mlog(0, "Path adjustment required\n");
 
                        /*
                         * We've rotated the tree as much as we
@@ -1656,7 +2504,7 @@ static int ocfs2_rotate_tree_right(struct inode *inode,
                        goto out_ret_path;
                }
 
-               start = ocfs2_find_subtree_root(inode, left_path, right_path);
+               start = ocfs2_find_subtree_root(et, left_path, right_path);
 
                mlog(0, "Subtree root at index %d (blk %llu, depth %d)\n",
                     start,
@@ -1664,19 +2512,37 @@ static int ocfs2_rotate_tree_right(struct inode *inode,
                     right_path->p_tree_depth);
 
                ret = ocfs2_extend_rotate_transaction(handle, start,
-                                                     right_path);
+                                                     orig_credits, right_path);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
                }
 
-               ret = ocfs2_rotate_subtree_right(inode, handle, left_path,
+               ret = ocfs2_rotate_subtree_right(handle, et, left_path,
                                                 right_path, start);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
                }
 
+               if (split != SPLIT_NONE &&
+                   ocfs2_leftmost_rec_contains(path_leaf_el(right_path),
+                                               insert_cpos)) {
+                       /*
+                        * A rotate moves the rightmost left leaf
+                        * record over to the leftmost right leaf
+                        * slot. If we're doing an extent split
+                        * instead of a real insert, then we have to
+                        * check that the extent to be split wasn't
+                        * just moved over. If it was, then we can
+                        * exit here, passing left_path back -
+                        * ocfs2_split_extent() is smart enough to
+                        * search both leaves.
+                        */
+                       *ret_left_path = left_path;
+                       goto out_ret_path;
+               }
+
                /*
                 * There is no need to re-read the next right path
                 * as we know that it'll be our current left
@@ -1684,8 +2550,7 @@ static int ocfs2_rotate_tree_right(struct inode *inode,
                 */
                ocfs2_mv_path(right_path, left_path);
 
-               ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, right_path,
-                                                   &cpos);
+               ret = ocfs2_find_cpos_for_left_leaf(sb, right_path, &cpos);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
@@ -1699,1547 +2564,4838 @@ out_ret_path:
        return ret;
 }
 
-/*
- * Do the final bits of extent record insertion at the target leaf
- * list. If this leaf is part of an allocation tree, it is assumed
- * that the tree above has been prepared.
- */
-static void ocfs2_insert_at_leaf(struct ocfs2_extent_rec *insert_rec,
-                                struct ocfs2_extent_list *el,
-                                struct ocfs2_insert_type *insert,
-                                struct inode *inode)
+static int ocfs2_update_edge_lengths(handle_t *handle,
+                                    struct ocfs2_extent_tree *et,
+                                    int subtree_index, struct ocfs2_path *path)
 {
-       int i = insert->ins_contig_index;
-       unsigned int range;
+       int i, idx, ret;
        struct ocfs2_extent_rec *rec;
-
-       BUG_ON(el->l_tree_depth);
+       struct ocfs2_extent_list *el;
+       struct ocfs2_extent_block *eb;
+       u32 range;
 
        /*
-        * Contiguous insert - either left or right.
+        * In normal tree rotation process, we will never touch the
+        * tree branch above subtree_index and ocfs2_extend_rotate_transaction
+        * doesn't reserve the credits for them either.
+        *
+        * But we do have a special case here which will update the rightmost
+        * records for all the bh in the path.
+        * So we have to allocate extra credits and access them.
         */
-       if (insert->ins_contig != CONTIG_NONE) {
-               rec = &el->l_recs[i];
-               if (insert->ins_contig == CONTIG_LEFT) {
-                       rec->e_blkno = insert_rec->e_blkno;
-                       rec->e_cpos = insert_rec->e_cpos;
-               }
-               le32_add_cpu(&rec->e_clusters,
-                            le32_to_cpu(insert_rec->e_clusters));
-               return;
+       ret = ocfs2_extend_trans(handle,
+                                handle->h_buffer_credits + subtree_index);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
        }
 
-       /*
-        * Handle insert into an empty leaf.
-        */
-       if (le16_to_cpu(el->l_next_free_rec) == 0 ||
-           ((le16_to_cpu(el->l_next_free_rec) == 1) &&
-            ocfs2_is_empty_extent(&el->l_recs[0]))) {
-               el->l_recs[0] = *insert_rec;
-               el->l_next_free_rec = cpu_to_le16(1);
-               return;
+       ret = ocfs2_journal_access_path(et->et_ci, handle, path);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
        }
 
-       /*
-        * Appending insert.
-        */
-       if (insert->ins_appending == APPEND_TAIL) {
-               i = le16_to_cpu(el->l_next_free_rec) - 1;
-               rec = &el->l_recs[i];
-               range = le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters);
-               BUG_ON(le32_to_cpu(insert_rec->e_cpos) < range);
+       /* Path should always be rightmost. */
+       eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
+       BUG_ON(eb->h_next_leaf_blk != 0ULL);
 
-               mlog_bug_on_msg(le16_to_cpu(el->l_next_free_rec) >=
-                               le16_to_cpu(el->l_count),
-                               "inode %lu, depth %u, count %u, next free %u, "
-                               "rec.cpos %u, rec.clusters %u, "
-                               "insert.cpos %u, insert.clusters %u\n",
-                               inode->i_ino,
-                               le16_to_cpu(el->l_tree_depth),
-                               le16_to_cpu(el->l_count),
-                               le16_to_cpu(el->l_next_free_rec),
-                               le32_to_cpu(el->l_recs[i].e_cpos),
-                               le32_to_cpu(el->l_recs[i].e_clusters),
-                               le32_to_cpu(insert_rec->e_cpos),
-                               le32_to_cpu(insert_rec->e_clusters));
-               i++;
-               el->l_recs[i] = *insert_rec;
-               le16_add_cpu(&el->l_next_free_rec, 1);
-               return;
-       }
+       el = &eb->h_list;
+       BUG_ON(le16_to_cpu(el->l_next_free_rec) == 0);
+       idx = le16_to_cpu(el->l_next_free_rec) - 1;
+       rec = &el->l_recs[idx];
+       range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
 
-       /*
-        * Ok, we have to rotate.
-        *
-        * At this point, it is safe to assume that inserting into an
-        * empty leaf and appending to a leaf have both been handled
-        * above.
-        *
-        * This leaf needs to have space, either by the empty 1st
-        * extent record, or by virtue of an l_next_rec < l_count.
-        */
-       ocfs2_rotate_leaf(el, insert_rec);
+       for (i = 0; i < path->p_tree_depth; i++) {
+               el = path->p_node[i].el;
+               idx = le16_to_cpu(el->l_next_free_rec) - 1;
+               rec = &el->l_recs[idx];
+
+               rec->e_int_clusters = cpu_to_le32(range);
+               le32_add_cpu(&rec->e_int_clusters, -le32_to_cpu(rec->e_cpos));
+
+               ocfs2_journal_dirty(handle, path->p_node[i].bh);
+       }
+out:
+       return ret;
 }
 
-static inline void ocfs2_update_dinode_clusters(struct inode *inode,
-                                               struct ocfs2_dinode *di,
-                                               u32 clusters)
+static void ocfs2_unlink_path(handle_t *handle,
+                             struct ocfs2_extent_tree *et,
+                             struct ocfs2_cached_dealloc_ctxt *dealloc,
+                             struct ocfs2_path *path, int unlink_start)
 {
-       le32_add_cpu(&di->i_clusters, clusters);
-       spin_lock(&OCFS2_I(inode)->ip_lock);
-       OCFS2_I(inode)->ip_clusters = le32_to_cpu(di->i_clusters);
-       spin_unlock(&OCFS2_I(inode)->ip_lock);
+       int ret, i;
+       struct ocfs2_extent_block *eb;
+       struct ocfs2_extent_list *el;
+       struct buffer_head *bh;
+
+       for(i = unlink_start; i < path_num_items(path); i++) {
+               bh = path->p_node[i].bh;
+
+               eb = (struct ocfs2_extent_block *)bh->b_data;
+               /*
+                * Not all nodes might have had their final count
+                * decremented by the caller - handle this here.
+                */
+               el = &eb->h_list;
+               if (le16_to_cpu(el->l_next_free_rec) > 1) {
+                       mlog(ML_ERROR,
+                            "Inode %llu, attempted to remove extent block "
+                            "%llu with %u records\n",
+                            (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                            (unsigned long long)le64_to_cpu(eb->h_blkno),
+                            le16_to_cpu(el->l_next_free_rec));
+
+                       ocfs2_journal_dirty(handle, bh);
+                       ocfs2_remove_from_cache(et->et_ci, bh);
+                       continue;
+               }
+
+               el->l_next_free_rec = 0;
+               memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
+
+               ocfs2_journal_dirty(handle, bh);
+
+               ret = ocfs2_cache_extent_block_free(dealloc, eb);
+               if (ret)
+                       mlog_errno(ret);
+
+               ocfs2_remove_from_cache(et->et_ci, bh);
+       }
 }
 
-static int ocfs2_append_rec_to_path(struct inode *inode, handle_t *handle,
-                                   struct ocfs2_extent_rec *insert_rec,
-                                   struct ocfs2_path *right_path,
-                                   struct ocfs2_path **ret_left_path)
+static void ocfs2_unlink_subtree(handle_t *handle,
+                                struct ocfs2_extent_tree *et,
+                                struct ocfs2_path *left_path,
+                                struct ocfs2_path *right_path,
+                                int subtree_index,
+                                struct ocfs2_cached_dealloc_ctxt *dealloc)
 {
-       int ret, i, next_free;
-       struct buffer_head *bh;
+       int i;
+       struct buffer_head *root_bh = left_path->p_node[subtree_index].bh;
+       struct ocfs2_extent_list *root_el = left_path->p_node[subtree_index].el;
        struct ocfs2_extent_list *el;
-       struct ocfs2_path *left_path = NULL;
+       struct ocfs2_extent_block *eb;
 
-       *ret_left_path = NULL;
+       el = path_leaf_el(left_path);
 
-       /*
-        * If our appending insert is at the leftmost edge of a leaf,
-        * then we might need to update the rightmost records of the
-        * neighboring path.
-        */
-       el = path_leaf_el(right_path);
-       next_free = le16_to_cpu(el->l_next_free_rec);
-       if (next_free == 0 ||
-           (next_free == 1 && ocfs2_is_empty_extent(&el->l_recs[0]))) {
-               u32 left_cpos;
+       eb = (struct ocfs2_extent_block *)right_path->p_node[subtree_index + 1].bh->b_data;
 
-               ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, right_path,
-                                                   &left_cpos);
-               if (ret) {
-                       mlog_errno(ret);
-                       goto out;
-               }
+       for(i = 1; i < le16_to_cpu(root_el->l_next_free_rec); i++)
+               if (root_el->l_recs[i].e_blkno == eb->h_blkno)
+                       break;
 
-               mlog(0, "Append may need a left path update. cpos: %u, "
-                    "left_cpos: %u\n", le32_to_cpu(insert_rec->e_cpos),
-                    left_cpos);
+       BUG_ON(i >= le16_to_cpu(root_el->l_next_free_rec));
+
+       memset(&root_el->l_recs[i], 0, sizeof(struct ocfs2_extent_rec));
+       le16_add_cpu(&root_el->l_next_free_rec, -1);
+
+       eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
+       eb->h_next_leaf_blk = 0;
+
+       ocfs2_journal_dirty(handle, root_bh);
+       ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
+
+       ocfs2_unlink_path(handle, et, dealloc, right_path,
+                         subtree_index + 1);
+}
+
+static int ocfs2_rotate_subtree_left(handle_t *handle,
+                                    struct ocfs2_extent_tree *et,
+                                    struct ocfs2_path *left_path,
+                                    struct ocfs2_path *right_path,
+                                    int subtree_index,
+                                    struct ocfs2_cached_dealloc_ctxt *dealloc,
+                                    int *deleted)
+{
+       int ret, i, del_right_subtree = 0, right_has_empty = 0;
+       struct buffer_head *root_bh, *et_root_bh = path_root_bh(right_path);
+       struct ocfs2_extent_list *right_leaf_el, *left_leaf_el;
+       struct ocfs2_extent_block *eb;
+
+       *deleted = 0;
+
+       right_leaf_el = path_leaf_el(right_path);
+       left_leaf_el = path_leaf_el(left_path);
+       root_bh = left_path->p_node[subtree_index].bh;
+       BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
+
+       if (!ocfs2_is_empty_extent(&left_leaf_el->l_recs[0]))
+               return 0;
 
+       eb = (struct ocfs2_extent_block *)path_leaf_bh(right_path)->b_data;
+       if (ocfs2_is_empty_extent(&right_leaf_el->l_recs[0])) {
                /*
-                * No need to worry if the append is already in the
-                * leftmost leaf.
+                * It's legal for us to proceed if the right leaf is
+                * the rightmost one and it has an empty extent. There
+                * are two cases to handle - whether the leaf will be
+                * empty after removal or not. If the leaf isn't empty
+                * then just remove the empty extent up front. The
+                * next block will handle empty leaves by flagging
+                * them for unlink.
+                *
+                * Non rightmost leaves will throw -EAGAIN and the
+                * caller can manually move the subtree and retry.
                 */
-               if (left_cpos) {
-                       left_path = ocfs2_new_path(path_root_bh(right_path),
-                                                  path_root_el(right_path));
-                       if (!left_path) {
-                               ret = -ENOMEM;
-                               mlog_errno(ret);
-                               goto out;
-                       }
 
-                       ret = ocfs2_find_path(inode, left_path, left_cpos);
+               if (eb->h_next_leaf_blk != 0ULL)
+                       return -EAGAIN;
+
+               if (le16_to_cpu(right_leaf_el->l_next_free_rec) > 1) {
+                       ret = ocfs2_journal_access_eb(handle, et->et_ci,
+                                                     path_leaf_bh(right_path),
+                                                     OCFS2_JOURNAL_ACCESS_WRITE);
                        if (ret) {
                                mlog_errno(ret);
                                goto out;
                        }
 
-                       /*
-                        * ocfs2_insert_path() will pass the left_path to the
-                        * journal for us.
-                        */
-               }
-       }
-
-       ret = ocfs2_journal_access_path(inode, handle, right_path);
-       if (ret) {
-               mlog_errno(ret);
-               goto out;
+                       ocfs2_remove_empty_extent(right_leaf_el);
+               } else
+                       right_has_empty = 1;
        }
 
-       el = path_root_el(right_path);
-       bh = path_root_bh(right_path);
-       i = 0;
-       while (1) {
-               next_free = le16_to_cpu(el->l_next_free_rec);
-               if (next_free == 0) {
-                       ocfs2_error(inode->i_sb,
-                                   "Dinode %llu has a bad extent list",
-                                   (unsigned long long)OCFS2_I(inode)->ip_blkno);
-                       ret = -EIO;
+       if (eb->h_next_leaf_blk == 0ULL &&
+           le16_to_cpu(right_leaf_el->l_next_free_rec) == 1) {
+               /*
+                * We have to update i_last_eb_blk during the meta
+                * data delete.
+                */
+               ret = ocfs2_et_root_journal_access(handle, et,
+                                                  OCFS2_JOURNAL_ACCESS_WRITE);
+               if (ret) {
+                       mlog_errno(ret);
                        goto out;
                }
 
-               el->l_recs[next_free - 1].e_clusters = insert_rec->e_cpos;
-               le32_add_cpu(&el->l_recs[next_free - 1].e_clusters,
-                            le32_to_cpu(insert_rec->e_clusters));
-               le32_add_cpu(&el->l_recs[next_free - 1].e_clusters,
-                           -le32_to_cpu(el->l_recs[next_free - 1].e_cpos));
-
-               ret = ocfs2_journal_dirty(handle, bh);
-               if (ret)
-                       mlog_errno(ret);
-
-               if (++i >= right_path->p_tree_depth)
-                       break;
-
-               bh = right_path->p_node[i].bh;
-               el = right_path->p_node[i].el;
+               del_right_subtree = 1;
        }
 
-       *ret_left_path = left_path;
-       ret = 0;
-out:
-       if (ret != 0)
-               ocfs2_free_path(left_path);
-
-       return ret;
-}
-
-/*
- * This function only does inserts on an allocation b-tree. For dinode
- * lists, ocfs2_insert_at_leaf() is called directly.
- *
- * right_path is the path we want to do the actual insert
- * in. left_path should only be passed in if we need to update that
- * portion of the tree after an edge insert.
- */
-static int ocfs2_insert_path(struct inode *inode,
-                            handle_t *handle,
-                            struct ocfs2_path *left_path,
-                            struct ocfs2_path *right_path,
-                            struct ocfs2_extent_rec *insert_rec,
-                            struct ocfs2_insert_type *insert)
-{
-       int ret, subtree_index;
-       struct buffer_head *leaf_bh = path_leaf_bh(right_path);
-       struct ocfs2_extent_list *el;
-
        /*
-        * Pass both paths to the journal. The majority of inserts
-        * will be touching all components anyway.
+        * Getting here with an empty extent in the right path implies
+        * that it's the rightmost path and will be deleted.
         */
-       ret = ocfs2_journal_access_path(inode, handle, right_path);
-       if (ret < 0) {
+       BUG_ON(right_has_empty && !del_right_subtree);
+
+       ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
+                                          subtree_index);
+       if (ret) {
                mlog_errno(ret);
                goto out;
        }
 
-       if (left_path) {
-               int credits = handle->h_buffer_credits;
-
-               /*
-                * There's a chance that left_path got passed back to
-                * us without being accounted for in the
-                * journal. Extend our transaction here to be sure we
-                * can change those blocks.
-                */
-               credits += left_path->p_tree_depth;
-
-               ret = ocfs2_extend_trans(handle, credits);
-               if (ret < 0) {
+       for(i = subtree_index + 1; i < path_num_items(right_path); i++) {
+               ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                  right_path, i);
+               if (ret) {
                        mlog_errno(ret);
                        goto out;
                }
 
-               ret = ocfs2_journal_access_path(inode, handle, left_path);
-               if (ret < 0) {
+               ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                  left_path, i);
+               if (ret) {
                        mlog_errno(ret);
                        goto out;
                }
        }
 
-       el = path_leaf_el(right_path);
+       if (!right_has_empty) {
+               /*
+                * Only do this if we're moving a real
+                * record. Otherwise, the action is delayed until
+                * after removal of the right path in which case we
+                * can do a simple shift to remove the empty extent.
+                */
+               ocfs2_rotate_leaf(left_leaf_el, &right_leaf_el->l_recs[0]);
+               memset(&right_leaf_el->l_recs[0], 0,
+                      sizeof(struct ocfs2_extent_rec));
+       }
+       if (eb->h_next_leaf_blk == 0ULL) {
+               /*
+                * Move recs over to get rid of empty extent, decrease
+                * next_free. This is allowed to remove the last
+                * extent in our leaf (setting l_next_free_rec to
+                * zero) - the delete code below won't care.
+                */
+               ocfs2_remove_empty_extent(right_leaf_el);
+       }
 
-       ocfs2_insert_at_leaf(insert_rec, el, insert, inode);
-       ret = ocfs2_journal_dirty(handle, leaf_bh);
+       ret = ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
+       if (ret)
+               mlog_errno(ret);
+       ret = ocfs2_journal_dirty(handle, path_leaf_bh(right_path));
        if (ret)
                mlog_errno(ret);
 
-       if (left_path) {
+       if (del_right_subtree) {
+               ocfs2_unlink_subtree(handle, et, left_path, right_path,
+                                    subtree_index, dealloc);
+               ret = ocfs2_update_edge_lengths(handle, et, subtree_index,
+                                               left_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
+               ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));
+
                /*
-                * The rotate code has indicated that we need to fix
-                * up portions of the tree after the insert.
-                *
-                * XXX: Should we extend the transaction here?
+                * Removal of the extent in the left leaf was skipped
+                * above so we could delete the right path
+                * 1st.
                 */
-               subtree_index = ocfs2_find_subtree_root(inode, left_path,
-                                                       right_path);
-               ocfs2_complete_edge_insert(inode, handle, left_path,
-                                          right_path, subtree_index);
-       }
+               if (right_has_empty)
+                       ocfs2_remove_empty_extent(left_leaf_el);
+
+               ret = ocfs2_journal_dirty(handle, et_root_bh);
+               if (ret)
+                       mlog_errno(ret);
+
+               *deleted = 1;
+       } else
+               ocfs2_complete_edge_insert(handle, left_path, right_path,
+                                          subtree_index);
 
-       ret = 0;
 out:
        return ret;
 }
 
-static int ocfs2_do_insert_extent(struct inode *inode,
-                                 handle_t *handle,
-                                 struct buffer_head *di_bh,
-                                 struct ocfs2_extent_rec *insert_rec,
-                                 struct ocfs2_insert_type *type)
+/*
+ * Given a full path, determine what cpos value would return us a path
+ * containing the leaf immediately to the right of the current one.
+ *
+ * Will return zero if the path passed in is already the rightmost path.
+ *
+ * This looks similar, but is subtly different to
+ * ocfs2_find_cpos_for_left_leaf().
+ */
+static int ocfs2_find_cpos_for_right_leaf(struct super_block *sb,
+                                         struct ocfs2_path *path, u32 *cpos)
 {
-       int ret, rotate = 0;
-       u32 cpos;
-       struct ocfs2_path *right_path = NULL;
-       struct ocfs2_path *left_path = NULL;
-       struct ocfs2_dinode *di;
-       struct ocfs2_extent_list *el;
+       int i, j, ret = 0;
+       u64 blkno;
+       struct ocfs2_extent_list *el;
+
+       *cpos = 0;
+
+       if (path->p_tree_depth == 0)
+               return 0;
+
+       blkno = path_leaf_bh(path)->b_blocknr;
+
+       /* Start at the tree node just above the leaf and work our way up. */
+       i = path->p_tree_depth - 1;
+       while (i >= 0) {
+               int next_free;
+
+               el = path->p_node[i].el;
+
+               /*
+                * Find the extent record just after the one in our
+                * path.
+                */
+               next_free = le16_to_cpu(el->l_next_free_rec);
+               for(j = 0; j < le16_to_cpu(el->l_next_free_rec); j++) {
+                       if (le64_to_cpu(el->l_recs[j].e_blkno) == blkno) {
+                               if (j == (next_free - 1)) {
+                                       if (i == 0) {
+                                               /*
+                                                * We've determined that the
+                                                * path specified is already
+                                                * the rightmost one - return a
+                                                * cpos of zero.
+                                                */
+                                               goto out;
+                                       }
+                                       /*
+                                        * The rightmost record points to our
+                                        * leaf - we need to travel up the
+                                        * tree one level.
+                                        */
+                                       goto next_node;
+                               }
+
+                               *cpos = le32_to_cpu(el->l_recs[j + 1].e_cpos);
+                               goto out;
+                       }
+               }
+
+               /*
+                * If we got here, we never found a valid node where
+                * the tree indicated one should be.
+                */
+               ocfs2_error(sb,
+                           "Invalid extent tree at extent block %llu\n",
+                           (unsigned long long)blkno);
+               ret = -EROFS;
+               goto out;
+
+next_node:
+               blkno = path->p_node[i].bh->b_blocknr;
+               i--;
+       }
+
+out:
+       return ret;
+}
+
+static int ocfs2_rotate_rightmost_leaf_left(handle_t *handle,
+                                           struct ocfs2_extent_tree *et,
+                                           struct ocfs2_path *path)
+{
+       int ret;
+       struct buffer_head *bh = path_leaf_bh(path);
+       struct ocfs2_extent_list *el = path_leaf_el(path);
 
-       di = (struct ocfs2_dinode *) di_bh->b_data;
-       el = &di->id2.i_list;
+       if (!ocfs2_is_empty_extent(&el->l_recs[0]))
+               return 0;
 
-       ret = ocfs2_journal_access(handle, inode, di_bh,
-                                  OCFS2_JOURNAL_ACCESS_WRITE);
+       ret = ocfs2_path_bh_journal_access(handle, et->et_ci, path,
+                                          path_num_items(path) - 1);
        if (ret) {
                mlog_errno(ret);
                goto out;
        }
 
-       if (le16_to_cpu(el->l_tree_depth) == 0) {
-               ocfs2_insert_at_leaf(insert_rec, el, type, inode);
-               goto out_update_clusters;
+       ocfs2_remove_empty_extent(el);
+
+       ret = ocfs2_journal_dirty(handle, bh);
+       if (ret)
+               mlog_errno(ret);
+
+out:
+       return ret;
+}
+
+static int __ocfs2_rotate_tree_left(handle_t *handle,
+                                   struct ocfs2_extent_tree *et,
+                                   int orig_credits,
+                                   struct ocfs2_path *path,
+                                   struct ocfs2_cached_dealloc_ctxt *dealloc,
+                                   struct ocfs2_path **empty_extent_path)
+{
+       int ret, subtree_root, deleted;
+       u32 right_cpos;
+       struct ocfs2_path *left_path = NULL;
+       struct ocfs2_path *right_path = NULL;
+       struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
+
+       BUG_ON(!ocfs2_is_empty_extent(&(path_leaf_el(path)->l_recs[0])));
+
+       *empty_extent_path = NULL;
+
+       ret = ocfs2_find_cpos_for_right_leaf(sb, path, &right_cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
        }
 
-       right_path = ocfs2_new_inode_path(di_bh);
-       if (!right_path) {
+       left_path = ocfs2_new_path_from_path(path);
+       if (!left_path) {
                ret = -ENOMEM;
                mlog_errno(ret);
                goto out;
        }
 
-       /*
-        * Determine the path to start with. Rotations need the
-        * rightmost path, everything else can go directly to the
-        * target leaf.
-        */
-       cpos = le32_to_cpu(insert_rec->e_cpos);
-       if (type->ins_appending == APPEND_NONE &&
-           type->ins_contig == CONTIG_NONE) {
-               rotate = 1;
-               cpos = UINT_MAX;
-       }
+       ocfs2_cp_path(left_path, path);
 
-       ret = ocfs2_find_path(inode, right_path, cpos);
-       if (ret) {
+       right_path = ocfs2_new_path_from_path(path);
+       if (!right_path) {
+               ret = -ENOMEM;
                mlog_errno(ret);
                goto out;
        }
 
-       /*
-        * Rotations and appends need special treatment - they modify
-        * parts of the tree's above them.
-        *
-        * Both might pass back a path immediate to the left of the
-        * one being inserted to. This will be cause
-        * ocfs2_insert_path() to modify the rightmost records of
-        * left_path to account for an edge insert.
-        *
-        * XXX: When modifying this code, keep in mind that an insert
-        * can wind up skipping both of these two special cases...
-        */
-       if (rotate) {
-               ret = ocfs2_rotate_tree_right(inode, handle,
-                                             le32_to_cpu(insert_rec->e_cpos),
-                                             right_path, &left_path);
+       while (right_cpos) {
+               ret = ocfs2_find_path(et->et_ci, right_path, right_cpos);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
                }
-       } else if (type->ins_appending == APPEND_TAIL
-                  && type->ins_contig != CONTIG_LEFT) {
-               ret = ocfs2_append_rec_to_path(inode, handle, insert_rec,
-                                              right_path, &left_path);
+
+               subtree_root = ocfs2_find_subtree_root(et, left_path,
+                                                      right_path);
+
+               mlog(0, "Subtree root at index %d (blk %llu, depth %d)\n",
+                    subtree_root,
+                    (unsigned long long)
+                    right_path->p_node[subtree_root].bh->b_blocknr,
+                    right_path->p_tree_depth);
+
+               ret = ocfs2_extend_rotate_transaction(handle, subtree_root,
+                                                     orig_credits, left_path);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
                }
-       }
 
-       ret = ocfs2_insert_path(inode, handle, left_path, right_path,
-                               insert_rec, type);
-       if (ret) {
-               mlog_errno(ret);
-               goto out;
-       }
+               /*
+                * Caller might still want to make changes to the
+                * tree root, so re-add it to the journal here.
+                */
+               ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                  left_path, 0);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-out_update_clusters:
-       ocfs2_update_dinode_clusters(inode, di,
-                                    le32_to_cpu(insert_rec->e_clusters));
+               ret = ocfs2_rotate_subtree_left(handle, et, left_path,
+                                               right_path, subtree_root,
+                                               dealloc, &deleted);
+               if (ret == -EAGAIN) {
+                       /*
+                        * The rotation has to temporarily stop due to
+                        * the right subtree having an empty
+                        * extent. Pass it back to the caller for a
+                        * fixup.
+                        */
+                       *empty_extent_path = right_path;
+                       right_path = NULL;
+                       goto out;
+               }
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       ret = ocfs2_journal_dirty(handle, di_bh);
-       if (ret)
-               mlog_errno(ret);
+               /*
+                * The subtree rotate might have removed records on
+                * the rightmost edge. If so, then rotation is
+                * complete.
+                */
+               if (deleted)
+                       break;
+
+               ocfs2_mv_path(left_path, right_path);
+
+               ret = ocfs2_find_cpos_for_right_leaf(sb, left_path,
+                                                    &right_cpos);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       }
 
 out:
-       ocfs2_free_path(left_path);
        ocfs2_free_path(right_path);
+       ocfs2_free_path(left_path);
 
        return ret;
 }
 
-static void ocfs2_figure_contig_type(struct inode *inode,
-                                    struct ocfs2_insert_type *insert,
-                                    struct ocfs2_extent_list *el,
-                                    struct ocfs2_extent_rec *insert_rec)
+static int ocfs2_remove_rightmost_path(handle_t *handle,
+                               struct ocfs2_extent_tree *et,
+                               struct ocfs2_path *path,
+                               struct ocfs2_cached_dealloc_ctxt *dealloc)
 {
-       int i;
-       enum ocfs2_contig_type contig_type = CONTIG_NONE;
+       int ret, subtree_index;
+       u32 cpos;
+       struct ocfs2_path *left_path = NULL;
+       struct ocfs2_extent_block *eb;
+       struct ocfs2_extent_list *el;
 
-       for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
-               contig_type = ocfs2_extent_contig(inode, &el->l_recs[i],
-                                                 insert_rec);
-               if (contig_type != CONTIG_NONE) {
-                       insert->ins_contig_index = i;
-                       break;
-               }
+
+       ret = ocfs2_et_sanity_check(et);
+       if (ret)
+               goto out;
+       /*
+        * There's two ways we handle this depending on
+        * whether path is the only existing one.
+        */
+       ret = ocfs2_extend_rotate_transaction(handle, 0,
+                                             handle->h_buffer_credits,
+                                             path);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
        }
-       insert->ins_contig = contig_type;
-}
 
-/*
- * This should only be called against the righmost leaf extent list.
- *
- * ocfs2_figure_appending_type() will figure out whether we'll have to
- * insert at the tail of the rightmost leaf.
- *
- * This should also work against the dinode list for tree's with 0
- * depth. If we consider the dinode list to be the rightmost leaf node
- * then the logic here makes sense.
- */
-static void ocfs2_figure_appending_type(struct ocfs2_insert_type *insert,
-                                       struct ocfs2_extent_list *el,
-                                       struct ocfs2_extent_rec *insert_rec)
-{
-       int i;
-       u32 cpos = le32_to_cpu(insert_rec->e_cpos);
-       struct ocfs2_extent_rec *rec;
+       ret = ocfs2_journal_access_path(et->et_ci, handle, path);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
 
-       insert->ins_appending = APPEND_NONE;
+       ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
+                                           path, &cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
 
-       BUG_ON(el->l_tree_depth);
+       if (cpos) {
+               /*
+                * We have a path to the left of this one - it needs
+                * an update too.
+                */
+               left_path = ocfs2_new_path_from_path(path);
+               if (!left_path) {
+                       ret = -ENOMEM;
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       if (!el->l_next_free_rec)
-               goto set_tail_append;
+               ret = ocfs2_find_path(et->et_ci, left_path, cpos);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       if (ocfs2_is_empty_extent(&el->l_recs[0])) {
-               /* Were all records empty? */
-               if (le16_to_cpu(el->l_next_free_rec) == 1)
-                       goto set_tail_append;
-       }
+               ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       i = le16_to_cpu(el->l_next_free_rec) - 1;
-       rec = &el->l_recs[i];
+               subtree_index = ocfs2_find_subtree_root(et, left_path, path);
 
-       if (cpos >= (le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)))
-               goto set_tail_append;
+               ocfs2_unlink_subtree(handle, et, left_path, path,
+                                    subtree_index, dealloc);
+               ret = ocfs2_update_edge_lengths(handle, et, subtree_index,
+                                               left_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       return;
+               eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
+               ocfs2_et_set_last_eb_blk(et, le64_to_cpu(eb->h_blkno));
+       } else {
+               /*
+                * 'path' is also the leftmost path which
+                * means it must be the only one. This gets
+                * handled differently because we want to
+                * revert the root back to having extents
+                * in-line.
+                */
+               ocfs2_unlink_path(handle, et, dealloc, path, 1);
 
-set_tail_append:
-       insert->ins_appending = APPEND_TAIL;
+               el = et->et_root_el;
+               el->l_tree_depth = 0;
+               el->l_next_free_rec = 0;
+               memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
+
+               ocfs2_et_set_last_eb_blk(et, 0);
+       }
+
+       ocfs2_journal_dirty(handle, path_root_bh(path));
+
+out:
+       ocfs2_free_path(left_path);
+       return ret;
 }
 
 /*
- * Helper function called at the begining of an insert.
+ * Left rotation of btree records.
  *
- * This computes a few things that are commonly used in the process of
- * inserting into the btree:
- *   - Whether the new extent is contiguous with an existing one.
- *   - The current tree depth.
- *   - Whether the insert is an appending one.
- *   - The total # of free records in the tree.
+ * In many ways, this is (unsurprisingly) the opposite of right
+ * rotation. We start at some non-rightmost path containing an empty
+ * extent in the leaf block. The code works its way to the rightmost
+ * path by rotating records to the left in every subtree.
  *
- * All of the information is stored on the ocfs2_insert_type
- * structure.
+ * This is used by any code which reduces the number of extent records
+ * in a leaf. After removal, an empty record should be placed in the
+ * leftmost list position.
+ *
+ * This won't handle a length update of the rightmost path records if
+ * the rightmost tree leaf record is removed so the caller is
+ * responsible for detecting and correcting that.
  */
-static int ocfs2_figure_insert_type(struct inode *inode,
-                                   struct buffer_head *di_bh,
-                                   struct buffer_head **last_eb_bh,
-                                   struct ocfs2_extent_rec *insert_rec,
-                                   struct ocfs2_insert_type *insert)
+static int ocfs2_rotate_tree_left(handle_t *handle,
+                                 struct ocfs2_extent_tree *et,
+                                 struct ocfs2_path *path,
+                                 struct ocfs2_cached_dealloc_ctxt *dealloc)
 {
-       int ret;
-       struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
+       int ret, orig_credits = handle->h_buffer_credits;
+       struct ocfs2_path *tmp_path = NULL, *restart_path = NULL;
        struct ocfs2_extent_block *eb;
        struct ocfs2_extent_list *el;
-       struct ocfs2_path *path = NULL;
-       struct buffer_head *bh = NULL;
 
-       el = &di->id2.i_list;
-       insert->ins_tree_depth = le16_to_cpu(el->l_tree_depth);
+       el = path_leaf_el(path);
+       if (!ocfs2_is_empty_extent(&el->l_recs[0]))
+               return 0;
 
-       if (el->l_tree_depth) {
+       if (path->p_tree_depth == 0) {
+rightmost_no_delete:
                /*
-                * If we have tree depth, we read in the
-                * rightmost extent block ahead of time as
-                * ocfs2_figure_insert_type() and ocfs2_add_branch()
-                * may want it later.
+                * Inline extents. This is trivially handled, so do
+                * it up front.
                 */
-               ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
-                                      le64_to_cpu(di->i_last_eb_blk), &bh,
-                                      OCFS2_BH_CACHED, inode);
-               if (ret) {
-                       mlog_exit(ret);
-                       goto out;
-               }
-               eb = (struct ocfs2_extent_block *) bh->b_data;
-               el = &eb->h_list;
+               ret = ocfs2_rotate_rightmost_leaf_left(handle, et, path);
+               if (ret)
+                       mlog_errno(ret);
+               goto out;
        }
 
        /*
-        * Unless we have a contiguous insert, we'll need to know if
-        * there is room left in our allocation tree for another
-        * extent record.
+        * Handle rightmost branch now. There's several cases:
+        *  1) simple rotation leaving records in there. That's trivial.
+        *  2) rotation requiring a branch delete - there's no more
+        *     records left. Two cases of this:
+        *     a) There are branches to the left.
+        *     b) This is also the leftmost (the only) branch.
         *
-        * XXX: This test is simplistic, we can search for empty
-        * extent records too.
+        *  1) is handled via ocfs2_rotate_rightmost_leaf_left()
+        *  2a) we need the left branch so that we can update it with the unlink
+        *  2b) we need to bring the root back to inline extents.
         */
-       insert->ins_free_records = le16_to_cpu(el->l_count) -
-               le16_to_cpu(el->l_next_free_rec);
 
-       if (!insert->ins_tree_depth) {
-               ocfs2_figure_contig_type(inode, insert, el, insert_rec);
-               ocfs2_figure_appending_type(insert, el, insert_rec);
-               return 0;
-       }
+       eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
+       el = &eb->h_list;
+       if (eb->h_next_leaf_blk == 0) {
+               /*
+                * This gets a bit tricky if we're going to delete the
+                * rightmost path. Get the other cases out of the way
+                * 1st.
+                */
+               if (le16_to_cpu(el->l_next_free_rec) > 1)
+                       goto rightmost_no_delete;
 
-       path = ocfs2_new_inode_path(di_bh);
-       if (!path) {
-               ret = -ENOMEM;
-               mlog_errno(ret);
+               if (le16_to_cpu(el->l_next_free_rec) == 0) {
+                       ret = -EIO;
+                       ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
+                                   "Owner %llu has empty extent block at %llu",
+                                   (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                                   (unsigned long long)le64_to_cpu(eb->h_blkno));
+                       goto out;
+               }
+
+               /*
+                * XXX: The caller can not trust "path" any more after
+                * this as it will have been deleted. What do we do?
+                *
+                * In theory the rotate-for-merge code will never get
+                * here because it'll always ask for a rotate in a
+                * nonempty list.
+                */
+
+               ret = ocfs2_remove_rightmost_path(handle, et, path,
+                                                 dealloc);
+               if (ret)
+                       mlog_errno(ret);
                goto out;
        }
 
        /*
-        * In the case that we're inserting past what the tree
-        * currently accounts for, ocfs2_find_path() will return for
-        * us the rightmost tree path. This is accounted for below in
-        * the appending code.
+        * Now we can loop, remembering the path we get from -EAGAIN
+        * and restarting from there.
         */
-       ret = ocfs2_find_path(inode, path, le32_to_cpu(insert_rec->e_cpos));
-       if (ret) {
+try_rotate:
+       ret = __ocfs2_rotate_tree_left(handle, et, orig_credits, path,
+                                      dealloc, &restart_path);
+       if (ret && ret != -EAGAIN) {
                mlog_errno(ret);
                goto out;
        }
 
-       el = path_leaf_el(path);
+       while (ret == -EAGAIN) {
+               tmp_path = restart_path;
+               restart_path = NULL;
 
-       /*
-        * Now that we have the path, there's two things we want to determine:
-        * 1) Contiguousness (also set contig_index if this is so)
-        *
-        * 2) Are we doing an append? We can trivially break this up
-         *     into two types of appends: simple record append, or a
-         *     rotate inside the tail leaf.
-        */
-       ocfs2_figure_contig_type(inode, insert, el, insert_rec);
+               ret = __ocfs2_rotate_tree_left(handle, et, orig_credits,
+                                              tmp_path, dealloc,
+                                              &restart_path);
+               if (ret && ret != -EAGAIN) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       /*
-        * The insert code isn't quite ready to deal with all cases of
-        * left contiguousness. Specifically, if it's an insert into
-        * the 1st record in a leaf, it will require the adjustment of
-        * e_clusters on the last record of the path directly to it's
-        * left. For now, just catch that case and fool the layers
-        * above us. This works just fine for tree_depth == 0, which
-        * is why we allow that above.
-        */
-       if (insert->ins_contig == CONTIG_LEFT &&
-           insert->ins_contig_index == 0)
-               insert->ins_contig = CONTIG_NONE;
+               ocfs2_free_path(tmp_path);
+               tmp_path = NULL;
 
-       /*
-        * Ok, so we can simply compare against last_eb to figure out
-        * whether the path doesn't exist. This will only happen in
-        * the case that we're doing a tail append, so maybe we can
-        * take advantage of that information somehow.
-        */
-       if (le64_to_cpu(di->i_last_eb_blk) == path_leaf_bh(path)->b_blocknr) {
-               /*
-                * Ok, ocfs2_find_path() returned us the rightmost
-                * tree path. This might be an appending insert. There are
-                * two cases:
-                *    1) We're doing a true append at the tail:
-                *      -This might even be off the end of the leaf
-                *    2) We're "appending" by rotating in the tail
-                */
-               ocfs2_figure_appending_type(insert, el, insert_rec);
+               if (ret == 0)
+                       goto try_rotate;
        }
 
 out:
-       ocfs2_free_path(path);
-
-       if (ret == 0)
-               *last_eb_bh = bh;
-       else
-               brelse(bh);
+       ocfs2_free_path(tmp_path);
+       ocfs2_free_path(restart_path);
        return ret;
 }
 
-/*
- * Insert an extent into an inode btree.
- *
- * The caller needs to update fe->i_clusters
- */
-int ocfs2_insert_extent(struct ocfs2_super *osb,
-                       handle_t *handle,
-                       struct inode *inode,
-                       struct buffer_head *fe_bh,
-                       u32 cpos,
-                       u64 start_blk,
-                       u32 new_clusters,
-                       struct ocfs2_alloc_context *meta_ac)
+static void ocfs2_cleanup_merge(struct ocfs2_extent_list *el,
+                               int index)
 {
-       int status, shift;
-       struct buffer_head *last_eb_bh = NULL;
-       struct buffer_head *bh = NULL;
-       struct ocfs2_insert_type insert = {0, };
-       struct ocfs2_extent_rec rec;
+       struct ocfs2_extent_rec *rec = &el->l_recs[index];
+       unsigned int size;
 
-       mlog(0, "add %u clusters at position %u to inode %llu\n",
-            new_clusters, cpos, (unsigned long long)OCFS2_I(inode)->ip_blkno);
+       if (rec->e_leaf_clusters == 0) {
+               /*
+                * We consumed all of the merged-from record. An empty
+                * extent cannot exist anywhere but the 1st array
+                * position, so move things over if the merged-from
+                * record doesn't occupy that position.
+                *
+                * This creates a new empty extent so the caller
+                * should be smart enough to have removed any existing
+                * ones.
+                */
+               if (index > 0) {
+                       BUG_ON(ocfs2_is_empty_extent(&el->l_recs[0]));
+                       size = index * sizeof(struct ocfs2_extent_rec);
+                       memmove(&el->l_recs[1], &el->l_recs[0], size);
+               }
 
-       mlog_bug_on_msg(!ocfs2_sparse_alloc(osb) &&
-                       (OCFS2_I(inode)->ip_clusters != cpos),
-                       "Device %s, asking for sparse allocation: inode %llu, "
-                       "cpos %u, clusters %u\n",
-                       osb->dev_str,
-                       (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos,
-                       OCFS2_I(inode)->ip_clusters);
+               /*
+                * Always memset - the caller doesn't check whether it
+                * created an empty extent, so there could be junk in
+                * the other fields.
+                */
+               memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
+       }
+}
 
-       rec.e_cpos = cpu_to_le32(cpos);
-       rec.e_blkno = cpu_to_le64(start_blk);
-       rec.e_clusters = cpu_to_le32(new_clusters);
+static int ocfs2_get_right_path(struct ocfs2_extent_tree *et,
+                               struct ocfs2_path *left_path,
+                               struct ocfs2_path **ret_right_path)
+{
+       int ret;
+       u32 right_cpos;
+       struct ocfs2_path *right_path = NULL;
+       struct ocfs2_extent_list *left_el;
 
-       status = ocfs2_figure_insert_type(inode, fe_bh, &last_eb_bh, &rec,
-                                         &insert);
-       if (status < 0) {
-               mlog_errno(status);
-               goto bail;
-       }
+       *ret_right_path = NULL;
 
-       mlog(0, "Insert.appending: %u, Insert.Contig: %u, "
-            "Insert.contig_index: %d, Insert.free_records: %d, "
-            "Insert.tree_depth: %d\n",
-            insert.ins_appending, insert.ins_contig, insert.ins_contig_index,
-            insert.ins_free_records, insert.ins_tree_depth);
+       /* This function shouldn't be called for non-trees. */
+       BUG_ON(left_path->p_tree_depth == 0);
 
-       /*
-        * Avoid growing the tree unless we're out of records and the
-        * insert type requres one.
-        */
-       if (insert.ins_contig != CONTIG_NONE || insert.ins_free_records)
-               goto out_add;
+       left_el = path_leaf_el(left_path);
+       BUG_ON(left_el->l_next_free_rec != left_el->l_count);
 
-       shift = ocfs2_find_branch_target(osb, inode, fe_bh, &bh);
-       if (shift < 0) {
-               status = shift;
-               mlog_errno(status);
-               goto bail;
+       ret = ocfs2_find_cpos_for_right_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
+                                            left_path, &right_cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
        }
 
-       /* We traveled all the way to the bottom of the allocation tree
-        * and didn't find room for any more extents - we need to add
-        * another tree level */
-       if (shift) {
-               BUG_ON(bh);
-               mlog(0, "need to shift tree depth "
-                    "(current = %d)\n", insert.ins_tree_depth);
+       /* This function shouldn't be called for the rightmost leaf. */
+       BUG_ON(right_cpos == 0);
 
-               /* ocfs2_shift_tree_depth will return us a buffer with
-                * the new extent block (so we can pass that to
-                * ocfs2_add_branch). */
-               status = ocfs2_shift_tree_depth(osb, handle, inode, fe_bh,
-                                               meta_ac, &bh);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
-               }
-               insert.ins_tree_depth++;
-               /* Special case: we have room now if we shifted from
-                * tree_depth 0 */
-               if (insert.ins_tree_depth == 1)
-                       goto out_add;
+       right_path = ocfs2_new_path_from_path(left_path);
+       if (!right_path) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
        }
 
-       /* call ocfs2_add_branch to add the final part of the tree with
-        * the new data. */
-       mlog(0, "add branch. bh = %p\n", bh);
-       status = ocfs2_add_branch(osb, handle, inode, fe_bh, bh, last_eb_bh,
-                                 meta_ac);
-       if (status < 0) {
-               mlog_errno(status);
-               goto bail;
+       ret = ocfs2_find_path(et->et_ci, right_path, right_cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
        }
 
-out_add:
-       /* Finally, we can add clusters. This might rotate the tree for us. */
-       status = ocfs2_do_insert_extent(inode, handle, fe_bh, &rec, &insert);
-       if (status < 0)
-               mlog_errno(status);
-
-bail:
-       if (bh)
-               brelse(bh);
-
-       if (last_eb_bh)
-               brelse(last_eb_bh);
-
-       mlog_exit(status);
-       return status;
+       *ret_right_path = right_path;
+out:
+       if (ret)
+               ocfs2_free_path(right_path);
+       return ret;
 }
 
-static inline int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb)
+/*
+ * Remove split_rec clusters from the record at index and merge them
+ * onto the beginning of the record "next" to it.
+ * For index < l_count - 1, the next means the extent rec at index + 1.
+ * For index == l_count - 1, the "next" means the 1st extent rec of the
+ * next extent block.
+ */
+static int ocfs2_merge_rec_right(struct ocfs2_path *left_path,
+                                handle_t *handle,
+                                struct ocfs2_extent_tree *et,
+                                struct ocfs2_extent_rec *split_rec,
+                                int index)
 {
-       struct buffer_head *tl_bh = osb->osb_tl_bh;
-       struct ocfs2_dinode *di;
-       struct ocfs2_truncate_log *tl;
-
-       di = (struct ocfs2_dinode *) tl_bh->b_data;
-       tl = &di->id2.i_dealloc;
+       int ret, next_free, i;
+       unsigned int split_clusters = le16_to_cpu(split_rec->e_leaf_clusters);
+       struct ocfs2_extent_rec *left_rec;
+       struct ocfs2_extent_rec *right_rec;
+       struct ocfs2_extent_list *right_el;
+       struct ocfs2_path *right_path = NULL;
+       int subtree_index = 0;
+       struct ocfs2_extent_list *el = path_leaf_el(left_path);
+       struct buffer_head *bh = path_leaf_bh(left_path);
+       struct buffer_head *root_bh = NULL;
+
+       BUG_ON(index >= le16_to_cpu(el->l_next_free_rec));
+       left_rec = &el->l_recs[index];
+
+       if (index == le16_to_cpu(el->l_next_free_rec) - 1 &&
+           le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count)) {
+               /* we meet with a cross extent block merge. */
+               ret = ocfs2_get_right_path(et, left_path, &right_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       mlog_bug_on_msg(le16_to_cpu(tl->tl_used) > le16_to_cpu(tl->tl_count),
-                       "slot %d, invalid truncate log parameters: used = "
-                       "%u, count = %u\n", osb->slot_num,
-                       le16_to_cpu(tl->tl_used), le16_to_cpu(tl->tl_count));
-       return le16_to_cpu(tl->tl_used) == le16_to_cpu(tl->tl_count);
-}
+               right_el = path_leaf_el(right_path);
+               next_free = le16_to_cpu(right_el->l_next_free_rec);
+               BUG_ON(next_free <= 0);
+               right_rec = &right_el->l_recs[0];
+               if (ocfs2_is_empty_extent(right_rec)) {
+                       BUG_ON(next_free <= 1);
+                       right_rec = &right_el->l_recs[1];
+               }
 
-static int ocfs2_truncate_log_can_coalesce(struct ocfs2_truncate_log *tl,
-                                          unsigned int new_start)
-{
-       unsigned int tail_index;
-       unsigned int current_tail;
+               BUG_ON(le32_to_cpu(left_rec->e_cpos) +
+                      le16_to_cpu(left_rec->e_leaf_clusters) !=
+                      le32_to_cpu(right_rec->e_cpos));
 
-       /* No records, nothing to coalesce */
-       if (!le16_to_cpu(tl->tl_used))
-               return 0;
+               subtree_index = ocfs2_find_subtree_root(et, left_path,
+                                                       right_path);
 
-       tail_index = le16_to_cpu(tl->tl_used) - 1;
-       current_tail = le32_to_cpu(tl->tl_recs[tail_index].t_start);
-       current_tail += le32_to_cpu(tl->tl_recs[tail_index].t_clusters);
+               ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
+                                                     handle->h_buffer_credits,
+                                                     right_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       return current_tail == new_start;
-}
+               root_bh = left_path->p_node[subtree_index].bh;
+               BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
 
-static int ocfs2_truncate_log_append(struct ocfs2_super *osb,
-                                    handle_t *handle,
-                                    u64 start_blk,
-                                    unsigned int num_clusters)
-{
-       int status, index;
-       unsigned int start_cluster, tl_count;
-       struct inode *tl_inode = osb->osb_tl_inode;
-       struct buffer_head *tl_bh = osb->osb_tl_bh;
-       struct ocfs2_dinode *di;
-       struct ocfs2_truncate_log *tl;
+               ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
+                                                  subtree_index);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       mlog_entry("start_blk = %llu, num_clusters = %u\n",
-                  (unsigned long long)start_blk, num_clusters);
+               for (i = subtree_index + 1;
+                    i < path_num_items(right_path); i++) {
+                       ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                          right_path, i);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
 
-       BUG_ON(mutex_trylock(&tl_inode->i_mutex));
+                       ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                          left_path, i);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
+               }
 
-       start_cluster = ocfs2_blocks_to_clusters(osb->sb, start_blk);
+       } else {
+               BUG_ON(index == le16_to_cpu(el->l_next_free_rec) - 1);
+               right_rec = &el->l_recs[index + 1];
+       }
 
-       di = (struct ocfs2_dinode *) tl_bh->b_data;
-       tl = &di->id2.i_dealloc;
-       if (!OCFS2_IS_VALID_DINODE(di)) {
-               OCFS2_RO_ON_INVALID_DINODE(osb->sb, di);
-               status = -EIO;
-               goto bail;
+       ret = ocfs2_path_bh_journal_access(handle, et->et_ci, left_path,
+                                          path_num_items(left_path) - 1);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
        }
 
-       tl_count = le16_to_cpu(tl->tl_count);
-       mlog_bug_on_msg(tl_count > ocfs2_truncate_recs_per_inode(osb->sb) ||
-                       tl_count == 0,
-                       "Truncate record count on #%llu invalid "
-                       "wanted %u, actual %u\n",
-                       (unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
-                       ocfs2_truncate_recs_per_inode(osb->sb),
-                       le16_to_cpu(tl->tl_count));
+       le16_add_cpu(&left_rec->e_leaf_clusters, -split_clusters);
 
-       /* Caller should have known to flush before calling us. */
-       index = le16_to_cpu(tl->tl_used);
-       if (index >= tl_count) {
-               status = -ENOSPC;
-               mlog_errno(status);
-               goto bail;
-       }
+       le32_add_cpu(&right_rec->e_cpos, -split_clusters);
+       le64_add_cpu(&right_rec->e_blkno,
+                    -ocfs2_clusters_to_blocks(ocfs2_metadata_cache_get_super(et->et_ci),
+                                              split_clusters));
+       le16_add_cpu(&right_rec->e_leaf_clusters, split_clusters);
 
-       status = ocfs2_journal_access(handle, tl_inode, tl_bh,
-                                     OCFS2_JOURNAL_ACCESS_WRITE);
-       if (status < 0) {
-               mlog_errno(status);
-               goto bail;
+       ocfs2_cleanup_merge(el, index);
+
+       ret = ocfs2_journal_dirty(handle, bh);
+       if (ret)
+               mlog_errno(ret);
+
+       if (right_path) {
+               ret = ocfs2_journal_dirty(handle, path_leaf_bh(right_path));
+               if (ret)
+                       mlog_errno(ret);
+
+               ocfs2_complete_edge_insert(handle, left_path, right_path,
+                                          subtree_index);
        }
+out:
+       if (right_path)
+               ocfs2_free_path(right_path);
+       return ret;
+}
 
-       mlog(0, "Log truncate of %u clusters starting at cluster %u to "
-            "%llu (index = %d)\n", num_clusters, start_cluster,
-            (unsigned long long)OCFS2_I(tl_inode)->ip_blkno, index);
+static int ocfs2_get_left_path(struct ocfs2_extent_tree *et,
+                              struct ocfs2_path *right_path,
+                              struct ocfs2_path **ret_left_path)
+{
+       int ret;
+       u32 left_cpos;
+       struct ocfs2_path *left_path = NULL;
 
-       if (ocfs2_truncate_log_can_coalesce(tl, start_cluster)) {
-               /*
-                * Move index back to the record we are coalescing with.
-                * ocfs2_truncate_log_can_coalesce() guarantees nonzero
-                */
-               index--;
+       *ret_left_path = NULL;
 
-               num_clusters += le32_to_cpu(tl->tl_recs[index].t_clusters);
-               mlog(0, "Coalesce with index %u (start = %u, clusters = %u)\n",
-                    index, le32_to_cpu(tl->tl_recs[index].t_start),
-                    num_clusters);
-       } else {
-               tl->tl_recs[index].t_start = cpu_to_le32(start_cluster);
-               tl->tl_used = cpu_to_le16(index + 1);
+       /* This function shouldn't be called for non-trees. */
+       BUG_ON(right_path->p_tree_depth == 0);
+
+       ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
+                                           right_path, &left_cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
        }
-       tl->tl_recs[index].t_clusters = cpu_to_le32(num_clusters);
 
-       status = ocfs2_journal_dirty(handle, tl_bh);
-       if (status < 0) {
-               mlog_errno(status);
-               goto bail;
+       /* This function shouldn't be called for the leftmost leaf. */
+       BUG_ON(left_cpos == 0);
+
+       left_path = ocfs2_new_path_from_path(right_path);
+       if (!left_path) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
        }
 
-bail:
-       mlog_exit(status);
-       return status;
+       ret = ocfs2_find_path(et->et_ci, left_path, left_cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       *ret_left_path = left_path;
+out:
+       if (ret)
+               ocfs2_free_path(left_path);
+       return ret;
 }
 
-static int ocfs2_replay_truncate_records(struct ocfs2_super *osb,
-                                        handle_t *handle,
-                                        struct inode *data_alloc_inode,
-                                        struct buffer_head *data_alloc_bh)
+/*
+ * Remove split_rec clusters from the record at index and merge them
+ * onto the tail of the record "before" it.
+ * For index > 0, the "before" means the extent rec at index - 1.
+ *
+ * For index == 0, the "before" means the last record of the previous
+ * extent block. And there is also a situation that we may need to
+ * remove the rightmost leaf extent block in the right_path and change
+ * the right path to indicate the new rightmost path.
+ */
+static int ocfs2_merge_rec_left(struct ocfs2_path *right_path,
+                               handle_t *handle,
+                               struct ocfs2_extent_tree *et,
+                               struct ocfs2_extent_rec *split_rec,
+                               struct ocfs2_cached_dealloc_ctxt *dealloc,
+                               int index)
 {
-       int status = 0;
-       int i;
-       unsigned int num_clusters;
-       u64 start_blk;
-       struct ocfs2_truncate_rec rec;
-       struct ocfs2_dinode *di;
-       struct ocfs2_truncate_log *tl;
-       struct inode *tl_inode = osb->osb_tl_inode;
-       struct buffer_head *tl_bh = osb->osb_tl_bh;
-
-       mlog_entry_void();
-
-       di = (struct ocfs2_dinode *) tl_bh->b_data;
-       tl = &di->id2.i_dealloc;
-       i = le16_to_cpu(tl->tl_used) - 1;
-       while (i >= 0) {
-               /* Caller has given us at least enough credits to
-                * update the truncate log dinode */
-               status = ocfs2_journal_access(handle, tl_inode, tl_bh,
-                                             OCFS2_JOURNAL_ACCESS_WRITE);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
-               }
+       int ret, i, subtree_index = 0, has_empty_extent = 0;
+       unsigned int split_clusters = le16_to_cpu(split_rec->e_leaf_clusters);
+       struct ocfs2_extent_rec *left_rec;
+       struct ocfs2_extent_rec *right_rec;
+       struct ocfs2_extent_list *el = path_leaf_el(right_path);
+       struct buffer_head *bh = path_leaf_bh(right_path);
+       struct buffer_head *root_bh = NULL;
+       struct ocfs2_path *left_path = NULL;
+       struct ocfs2_extent_list *left_el;
 
-               tl->tl_used = cpu_to_le16(i);
+       BUG_ON(index < 0);
 
-               status = ocfs2_journal_dirty(handle, tl_bh);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
+       right_rec = &el->l_recs[index];
+       if (index == 0) {
+               /* we meet with a cross extent block merge. */
+               ret = ocfs2_get_left_path(et, right_path, &left_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
                }
 
-               /* TODO: Perhaps we can calculate the bulk of the
-                * credits up front rather than extending like
-                * this. */
-               status = ocfs2_extend_trans(handle,
-                                           OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
-               }
+               left_el = path_leaf_el(left_path);
+               BUG_ON(le16_to_cpu(left_el->l_next_free_rec) !=
+                      le16_to_cpu(left_el->l_count));
 
-               rec = tl->tl_recs[i];
-               start_blk = ocfs2_clusters_to_blocks(data_alloc_inode->i_sb,
-                                                   le32_to_cpu(rec.t_start));
-               num_clusters = le32_to_cpu(rec.t_clusters);
+               left_rec = &left_el->l_recs[
+                               le16_to_cpu(left_el->l_next_free_rec) - 1];
+               BUG_ON(le32_to_cpu(left_rec->e_cpos) +
+                      le16_to_cpu(left_rec->e_leaf_clusters) !=
+                      le32_to_cpu(split_rec->e_cpos));
 
-               /* if start_blk is not set, we ignore the record as
-                * invalid. */
-               if (start_blk) {
-                       mlog(0, "free record %d, start = %u, clusters = %u\n",
-                            i, le32_to_cpu(rec.t_start), num_clusters);
+               subtree_index = ocfs2_find_subtree_root(et, left_path,
+                                                       right_path);
 
-                       status = ocfs2_free_clusters(handle, data_alloc_inode,
-                                                    data_alloc_bh, start_blk,
-                                                    num_clusters);
-                       if (status < 0) {
-                               mlog_errno(status);
-                               goto bail;
-                       }
+               ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
+                                                     handle->h_buffer_credits,
+                                                     left_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
                }
-               i--;
-       }
-
-bail:
-       mlog_exit(status);
-       return status;
-}
 
-/* Expects you to already be holding tl_inode->i_mutex */
-static int __ocfs2_flush_truncate_log(struct ocfs2_super *osb)
-{
-       int status;
-       unsigned int num_to_flush;
-       handle_t *handle;
-       struct inode *tl_inode = osb->osb_tl_inode;
-       struct inode *data_alloc_inode = NULL;
-       struct buffer_head *tl_bh = osb->osb_tl_bh;
-       struct buffer_head *data_alloc_bh = NULL;
-       struct ocfs2_dinode *di;
-       struct ocfs2_truncate_log *tl;
+               root_bh = left_path->p_node[subtree_index].bh;
+               BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
 
-       mlog_entry_void();
+               ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
+                                                  subtree_index);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-       BUG_ON(mutex_trylock(&tl_inode->i_mutex));
+               for (i = subtree_index + 1;
+                    i < path_num_items(right_path); i++) {
+                       ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                          right_path, i);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
 
-       di = (struct ocfs2_dinode *) tl_bh->b_data;
-       tl = &di->id2.i_dealloc;
-       if (!OCFS2_IS_VALID_DINODE(di)) {
-               OCFS2_RO_ON_INVALID_DINODE(osb->sb, di);
-               status = -EIO;
-               goto out;
+                       ret = ocfs2_path_bh_journal_access(handle, et->et_ci,
+                                                          left_path, i);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
+               }
+       } else {
+               left_rec = &el->l_recs[index - 1];
+               if (ocfs2_is_empty_extent(&el->l_recs[0]))
+                       has_empty_extent = 1;
        }
 
-       num_to_flush = le16_to_cpu(tl->tl_used);
-       mlog(0, "Flush %u records from truncate log #%llu\n",
-            num_to_flush, (unsigned long long)OCFS2_I(tl_inode)->ip_blkno);
-       if (!num_to_flush) {
-               status = 0;
+       ret = ocfs2_path_bh_journal_access(handle, et->et_ci, right_path,
+                                          path_num_items(right_path) - 1);
+       if (ret) {
+               mlog_errno(ret);
                goto out;
        }
 
-       data_alloc_inode = ocfs2_get_system_file_inode(osb,
-                                                      GLOBAL_BITMAP_SYSTEM_INODE,
-                                                      OCFS2_INVALID_SLOT);
-       if (!data_alloc_inode) {
-               status = -EINVAL;
-               mlog(ML_ERROR, "Could not get bitmap inode!\n");
-               goto out;
-       }
+       if (has_empty_extent && index == 1) {
+               /*
+                * The easy case - we can just plop the record right in.
+                */
+               *left_rec = *split_rec;
 
-       mutex_lock(&data_alloc_inode->i_mutex);
+               has_empty_extent = 0;
+       } else
+               le16_add_cpu(&left_rec->e_leaf_clusters, split_clusters);
 
-       status = ocfs2_meta_lock(data_alloc_inode, &data_alloc_bh, 1);
-       if (status < 0) {
-               mlog_errno(status);
-               goto out_mutex;
-       }
+       le32_add_cpu(&right_rec->e_cpos, split_clusters);
+       le64_add_cpu(&right_rec->e_blkno,
+                    ocfs2_clusters_to_blocks(ocfs2_metadata_cache_get_super(et->et_ci),
+                                             split_clusters));
+       le16_add_cpu(&right_rec->e_leaf_clusters, -split_clusters);
 
-       handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
-       if (IS_ERR(handle)) {
-               status = PTR_ERR(handle);
-               mlog_errno(status);
-               goto out_unlock;
-       }
+       ocfs2_cleanup_merge(el, index);
 
-       status = ocfs2_replay_truncate_records(osb, handle, data_alloc_inode,
-                                              data_alloc_bh);
-       if (status < 0)
-               mlog_errno(status);
+       ret = ocfs2_journal_dirty(handle, bh);
+       if (ret)
+               mlog_errno(ret);
 
-       ocfs2_commit_trans(osb, handle);
+       if (left_path) {
+               ret = ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
+               if (ret)
+                       mlog_errno(ret);
 
-out_unlock:
-       brelse(data_alloc_bh);
-       ocfs2_meta_unlock(data_alloc_inode, 1);
+               /*
+                * In the situation that the right_rec is empty and the extent
+                * block is empty also,  ocfs2_complete_edge_insert can't handle
+                * it and we need to delete the right extent block.
+                */
+               if (le16_to_cpu(right_rec->e_leaf_clusters) == 0 &&
+                   le16_to_cpu(el->l_next_free_rec) == 1) {
 
-out_mutex:
-       mutex_unlock(&data_alloc_inode->i_mutex);
-       iput(data_alloc_inode);
+                       ret = ocfs2_remove_rightmost_path(handle, et,
+                                                         right_path,
+                                                         dealloc);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
 
+                       /* Now the rightmost extent block has been deleted.
+                        * So we use the new rightmost path.
+                        */
+                       ocfs2_mv_path(right_path, left_path);
+                       left_path = NULL;
+               } else
+                       ocfs2_complete_edge_insert(handle, left_path,
+                                                  right_path, subtree_index);
+       }
 out:
-       mlog_exit(status);
-       return status;
+       if (left_path)
+               ocfs2_free_path(left_path);
+       return ret;
 }
 
-int ocfs2_flush_truncate_log(struct ocfs2_super *osb)
+static int ocfs2_try_to_merge_extent(handle_t *handle,
+                                    struct ocfs2_extent_tree *et,
+                                    struct ocfs2_path *path,
+                                    int split_index,
+                                    struct ocfs2_extent_rec *split_rec,
+                                    struct ocfs2_cached_dealloc_ctxt *dealloc,
+                                    struct ocfs2_merge_ctxt *ctxt)
 {
-       int status;
-       struct inode *tl_inode = osb->osb_tl_inode;
+       int ret = 0;
+       struct ocfs2_extent_list *el = path_leaf_el(path);
+       struct ocfs2_extent_rec *rec = &el->l_recs[split_index];
 
-       mutex_lock(&tl_inode->i_mutex);
-       status = __ocfs2_flush_truncate_log(osb);
-       mutex_unlock(&tl_inode->i_mutex);
+       BUG_ON(ctxt->c_contig_type == CONTIG_NONE);
 
-       return status;
-}
+       if (ctxt->c_split_covers_rec && ctxt->c_has_empty_extent) {
+               /*
+                * The merge code will need to create an empty
+                * extent to take the place of the newly
+                * emptied slot. Remove any pre-existing empty
+                * extents - having more than one in a leaf is
+                * illegal.
+                */
+               ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+               split_index--;
+               rec = &el->l_recs[split_index];
+       }
 
-static void ocfs2_truncate_log_worker(struct work_struct *work)
-{
+       if (ctxt->c_contig_type == CONTIG_LEFTRIGHT) {
+               /*
+                * Left-right contig implies this.
+                */
+               BUG_ON(!ctxt->c_split_covers_rec);
+
+               /*
+                * Since the leftright insert always covers the entire
+                * extent, this call will delete the insert record
+                * entirely, resulting in an empty extent record added to
+                * the extent block.
+                *
+                * Since the adding of an empty extent shifts
+                * everything back to the right, there's no need to
+                * update split_index here.
+                *
+                * When the split_index is zero, we need to merge it to the
+                * prevoius extent block. It is more efficient and easier
+                * if we do merge_right first and merge_left later.
+                */
+               ret = ocfs2_merge_rec_right(path, handle, et, split_rec,
+                                           split_index);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               /*
+                * We can only get this from logic error above.
+                */
+               BUG_ON(!ocfs2_is_empty_extent(&el->l_recs[0]));
+
+               /* The merge left us with an empty extent, remove it. */
+               ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               rec = &el->l_recs[split_index];
+
+               /*
+                * Note that we don't pass split_rec here on purpose -
+                * we've merged it into the rec already.
+                */
+               ret = ocfs2_merge_rec_left(path, handle, et, rec,
+                                          dealloc, split_index);
+
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
+               /*
+                * Error from this last rotate is not critical, so
+                * print but don't bubble it up.
+                */
+               if (ret)
+                       mlog_errno(ret);
+               ret = 0;
+       } else {
+               /*
+                * Merge a record to the left or right.
+                *
+                * 'contig_type' is relative to the existing record,
+                * so for example, if we're "right contig", it's to
+                * the record on the left (hence the left merge).
+                */
+               if (ctxt->c_contig_type == CONTIG_RIGHT) {
+                       ret = ocfs2_merge_rec_left(path, handle, et,
+                                                  split_rec, dealloc,
+                                                  split_index);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
+               } else {
+                       ret = ocfs2_merge_rec_right(path, handle,
+                                                   et, split_rec,
+                                                   split_index);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
+               }
+
+               if (ctxt->c_split_covers_rec) {
+                       /*
+                        * The merge may have left an empty extent in
+                        * our leaf. Try to rotate it away.
+                        */
+                       ret = ocfs2_rotate_tree_left(handle, et, path,
+                                                    dealloc);
+                       if (ret)
+                               mlog_errno(ret);
+                       ret = 0;
+               }
+       }
+
+out:
+       return ret;
+}
+
+static void ocfs2_subtract_from_rec(struct super_block *sb,
+                                   enum ocfs2_split_type split,
+                                   struct ocfs2_extent_rec *rec,
+                                   struct ocfs2_extent_rec *split_rec)
+{
+       u64 len_blocks;
+
+       len_blocks = ocfs2_clusters_to_blocks(sb,
+                               le16_to_cpu(split_rec->e_leaf_clusters));
+
+       if (split == SPLIT_LEFT) {
+               /*
+                * Region is on the left edge of the existing
+                * record.
+                */
+               le32_add_cpu(&rec->e_cpos,
+                            le16_to_cpu(split_rec->e_leaf_clusters));
+               le64_add_cpu(&rec->e_blkno, len_blocks);
+               le16_add_cpu(&rec->e_leaf_clusters,
+                            -le16_to_cpu(split_rec->e_leaf_clusters));
+       } else {
+               /*
+                * Region is on the right edge of the existing
+                * record.
+                */
+               le16_add_cpu(&rec->e_leaf_clusters,
+                            -le16_to_cpu(split_rec->e_leaf_clusters));
+       }
+}
+
+/*
+ * Do the final bits of extent record insertion at the target leaf
+ * list. If this leaf is part of an allocation tree, it is assumed
+ * that the tree above has been prepared.
+ */
+static void ocfs2_insert_at_leaf(struct ocfs2_extent_tree *et,
+                                struct ocfs2_extent_rec *insert_rec,
+                                struct ocfs2_extent_list *el,
+                                struct ocfs2_insert_type *insert)
+{
+       int i = insert->ins_contig_index;
+       unsigned int range;
+       struct ocfs2_extent_rec *rec;
+
+       BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
+
+       if (insert->ins_split != SPLIT_NONE) {
+               i = ocfs2_search_extent_list(el, le32_to_cpu(insert_rec->e_cpos));
+               BUG_ON(i == -1);
+               rec = &el->l_recs[i];
+               ocfs2_subtract_from_rec(ocfs2_metadata_cache_get_super(et->et_ci),
+                                       insert->ins_split, rec,
+                                       insert_rec);
+               goto rotate;
+       }
+
+       /*
+        * Contiguous insert - either left or right.
+        */
+       if (insert->ins_contig != CONTIG_NONE) {
+               rec = &el->l_recs[i];
+               if (insert->ins_contig == CONTIG_LEFT) {
+                       rec->e_blkno = insert_rec->e_blkno;
+                       rec->e_cpos = insert_rec->e_cpos;
+               }
+               le16_add_cpu(&rec->e_leaf_clusters,
+                            le16_to_cpu(insert_rec->e_leaf_clusters));
+               return;
+       }
+
+       /*
+        * Handle insert into an empty leaf.
+        */
+       if (le16_to_cpu(el->l_next_free_rec) == 0 ||
+           ((le16_to_cpu(el->l_next_free_rec) == 1) &&
+            ocfs2_is_empty_extent(&el->l_recs[0]))) {
+               el->l_recs[0] = *insert_rec;
+               el->l_next_free_rec = cpu_to_le16(1);
+               return;
+       }
+
+       /*
+        * Appending insert.
+        */
+       if (insert->ins_appending == APPEND_TAIL) {
+               i = le16_to_cpu(el->l_next_free_rec) - 1;
+               rec = &el->l_recs[i];
+               range = le32_to_cpu(rec->e_cpos)
+                       + le16_to_cpu(rec->e_leaf_clusters);
+               BUG_ON(le32_to_cpu(insert_rec->e_cpos) < range);
+
+               mlog_bug_on_msg(le16_to_cpu(el->l_next_free_rec) >=
+                               le16_to_cpu(el->l_count),
+                               "owner %llu, depth %u, count %u, next free %u, "
+                               "rec.cpos %u, rec.clusters %u, "
+                               "insert.cpos %u, insert.clusters %u\n",
+                               ocfs2_metadata_cache_owner(et->et_ci),
+                               le16_to_cpu(el->l_tree_depth),
+                               le16_to_cpu(el->l_count),
+                               le16_to_cpu(el->l_next_free_rec),
+                               le32_to_cpu(el->l_recs[i].e_cpos),
+                               le16_to_cpu(el->l_recs[i].e_leaf_clusters),
+                               le32_to_cpu(insert_rec->e_cpos),
+                               le16_to_cpu(insert_rec->e_leaf_clusters));
+               i++;
+               el->l_recs[i] = *insert_rec;
+               le16_add_cpu(&el->l_next_free_rec, 1);
+               return;
+       }
+
+rotate:
+       /*
+        * Ok, we have to rotate.
+        *
+        * At this point, it is safe to assume that inserting into an
+        * empty leaf and appending to a leaf have both been handled
+        * above.
+        *
+        * This leaf needs to have space, either by the empty 1st
+        * extent record, or by virtue of an l_next_rec < l_count.
+        */
+       ocfs2_rotate_leaf(el, insert_rec);
+}
+
+static void ocfs2_adjust_rightmost_records(handle_t *handle,
+                                          struct ocfs2_extent_tree *et,
+                                          struct ocfs2_path *path,
+                                          struct ocfs2_extent_rec *insert_rec)
+{
+       int ret, i, next_free;
+       struct buffer_head *bh;
+       struct ocfs2_extent_list *el;
+       struct ocfs2_extent_rec *rec;
+
+       /*
+        * Update everything except the leaf block.
+        */
+       for (i = 0; i < path->p_tree_depth; i++) {
+               bh = path->p_node[i].bh;
+               el = path->p_node[i].el;
+
+               next_free = le16_to_cpu(el->l_next_free_rec);
+               if (next_free == 0) {
+                       ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
+                                   "Owner %llu has a bad extent list",
+                                   (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci));
+                       ret = -EIO;
+                       return;
+               }
+
+               rec = &el->l_recs[next_free - 1];
+
+               rec->e_int_clusters = insert_rec->e_cpos;
+               le32_add_cpu(&rec->e_int_clusters,
+                            le16_to_cpu(insert_rec->e_leaf_clusters));
+               le32_add_cpu(&rec->e_int_clusters,
+                            -le32_to_cpu(rec->e_cpos));
+
+               ret = ocfs2_journal_dirty(handle, bh);
+               if (ret)
+                       mlog_errno(ret);
+
+       }
+}
+
+static int ocfs2_append_rec_to_path(handle_t *handle,
+                                   struct ocfs2_extent_tree *et,
+                                   struct ocfs2_extent_rec *insert_rec,
+                                   struct ocfs2_path *right_path,
+                                   struct ocfs2_path **ret_left_path)
+{
+       int ret, next_free;
+       struct ocfs2_extent_list *el;
+       struct ocfs2_path *left_path = NULL;
+
+       *ret_left_path = NULL;
+
+       /*
+        * This shouldn't happen for non-trees. The extent rec cluster
+        * count manipulation below only works for interior nodes.
+        */
+       BUG_ON(right_path->p_tree_depth == 0);
+
+       /*
+        * If our appending insert is at the leftmost edge of a leaf,
+        * then we might need to update the rightmost records of the
+        * neighboring path.
+        */
+       el = path_leaf_el(right_path);
+       next_free = le16_to_cpu(el->l_next_free_rec);
+       if (next_free == 0 ||
+           (next_free == 1 && ocfs2_is_empty_extent(&el->l_recs[0]))) {
+               u32 left_cpos;
+
+               ret = ocfs2_find_cpos_for_left_leaf(ocfs2_metadata_cache_get_super(et->et_ci),
+                                                   right_path, &left_cpos);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               mlog(0, "Append may need a left path update. cpos: %u, "
+                    "left_cpos: %u\n", le32_to_cpu(insert_rec->e_cpos),
+                    left_cpos);
+
+               /*
+                * No need to worry if the append is already in the
+                * leftmost leaf.
+                */
+               if (left_cpos) {
+                       left_path = ocfs2_new_path_from_path(right_path);
+                       if (!left_path) {
+                               ret = -ENOMEM;
+                               mlog_errno(ret);
+                               goto out;
+                       }
+
+                       ret = ocfs2_find_path(et->et_ci, left_path,
+                                             left_cpos);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
+
+                       /*
+                        * ocfs2_insert_path() will pass the left_path to the
+                        * journal for us.
+                        */
+               }
+       }
+
+       ret = ocfs2_journal_access_path(et->et_ci, handle, right_path);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ocfs2_adjust_rightmost_records(handle, et, right_path, insert_rec);
+
+       *ret_left_path = left_path;
+       ret = 0;
+out:
+       if (ret != 0)
+               ocfs2_free_path(left_path);
+
+       return ret;
+}
+
+static void ocfs2_split_record(struct ocfs2_extent_tree *et,
+                              struct ocfs2_path *left_path,
+                              struct ocfs2_path *right_path,
+                              struct ocfs2_extent_rec *split_rec,
+                              enum ocfs2_split_type split)
+{
+       int index;
+       u32 cpos = le32_to_cpu(split_rec->e_cpos);
+       struct ocfs2_extent_list *left_el = NULL, *right_el, *insert_el, *el;
+       struct ocfs2_extent_rec *rec, *tmprec;
+
+       right_el = path_leaf_el(right_path);
+       if (left_path)
+               left_el = path_leaf_el(left_path);
+
+       el = right_el;
+       insert_el = right_el;
+       index = ocfs2_search_extent_list(el, cpos);
+       if (index != -1) {
+               if (index == 0 && left_path) {
+                       BUG_ON(ocfs2_is_empty_extent(&el->l_recs[0]));
+
+                       /*
+                        * This typically means that the record
+                        * started in the left path but moved to the
+                        * right as a result of rotation. We either
+                        * move the existing record to the left, or we
+                        * do the later insert there.
+                        *
+                        * In this case, the left path should always
+                        * exist as the rotate code will have passed
+                        * it back for a post-insert update.
+                        */
+
+                       if (split == SPLIT_LEFT) {
+                               /*
+                                * It's a left split. Since we know
+                                * that the rotate code gave us an
+                                * empty extent in the left path, we
+                                * can just do the insert there.
+                                */
+                               insert_el = left_el;
+                       } else {
+                               /*
+                                * Right split - we have to move the
+                                * existing record over to the left
+                                * leaf. The insert will be into the
+                                * newly created empty extent in the
+                                * right leaf.
+                                */
+                               tmprec = &right_el->l_recs[index];
+                               ocfs2_rotate_leaf(left_el, tmprec);
+                               el = left_el;
+
+                               memset(tmprec, 0, sizeof(*tmprec));
+                               index = ocfs2_search_extent_list(left_el, cpos);
+                               BUG_ON(index == -1);
+                       }
+               }
+       } else {
+               BUG_ON(!left_path);
+               BUG_ON(!ocfs2_is_empty_extent(&left_el->l_recs[0]));
+               /*
+                * Left path is easy - we can just allow the insert to
+                * happen.
+                */
+               el = left_el;
+               insert_el = left_el;
+               index = ocfs2_search_extent_list(el, cpos);
+               BUG_ON(index == -1);
+       }
+
+       rec = &el->l_recs[index];
+       ocfs2_subtract_from_rec(ocfs2_metadata_cache_get_super(et->et_ci),
+                               split, rec, split_rec);
+       ocfs2_rotate_leaf(insert_el, split_rec);
+}
+
+/*
+ * This function only does inserts on an allocation b-tree. For tree
+ * depth = 0, ocfs2_insert_at_leaf() is called directly.
+ *
+ * right_path is the path we want to do the actual insert
+ * in. left_path should only be passed in if we need to update that
+ * portion of the tree after an edge insert.
+ */
+static int ocfs2_insert_path(handle_t *handle,
+                            struct ocfs2_extent_tree *et,
+                            struct ocfs2_path *left_path,
+                            struct ocfs2_path *right_path,
+                            struct ocfs2_extent_rec *insert_rec,
+                            struct ocfs2_insert_type *insert)
+{
+       int ret, subtree_index;
+       struct buffer_head *leaf_bh = path_leaf_bh(right_path);
+
+       if (left_path) {
+               int credits = handle->h_buffer_credits;
+
+               /*
+                * There's a chance that left_path got passed back to
+                * us without being accounted for in the
+                * journal. Extend our transaction here to be sure we
+                * can change those blocks.
+                */
+               credits += left_path->p_tree_depth;
+
+               ret = ocfs2_extend_trans(handle, credits);
+               if (ret < 0) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
+               if (ret < 0) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       }
+
+       /*
+        * Pass both paths to the journal. The majority of inserts
+        * will be touching all components anyway.
+        */
+       ret = ocfs2_journal_access_path(et->et_ci, handle, right_path);
+       if (ret < 0) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       if (insert->ins_split != SPLIT_NONE) {
+               /*
+                * We could call ocfs2_insert_at_leaf() for some types
+                * of splits, but it's easier to just let one separate
+                * function sort it all out.
+                */
+               ocfs2_split_record(et, left_path, right_path,
+                                  insert_rec, insert->ins_split);
+
+               /*
+                * Split might have modified either leaf and we don't
+                * have a guarantee that the later edge insert will
+                * dirty this for us.
+                */
+               if (left_path)
+                       ret = ocfs2_journal_dirty(handle,
+                                                 path_leaf_bh(left_path));
+                       if (ret)
+                               mlog_errno(ret);
+       } else
+               ocfs2_insert_at_leaf(et, insert_rec, path_leaf_el(right_path),
+                                    insert);
+
+       ret = ocfs2_journal_dirty(handle, leaf_bh);
+       if (ret)
+               mlog_errno(ret);
+
+       if (left_path) {
+               /*
+                * The rotate code has indicated that we need to fix
+                * up portions of the tree after the insert.
+                *
+                * XXX: Should we extend the transaction here?
+                */
+               subtree_index = ocfs2_find_subtree_root(et, left_path,
+                                                       right_path);
+               ocfs2_complete_edge_insert(handle, left_path, right_path,
+                                          subtree_index);
+       }
+
+       ret = 0;
+out:
+       return ret;
+}
+
+static int ocfs2_do_insert_extent(handle_t *handle,
+                                 struct ocfs2_extent_tree *et,
+                                 struct ocfs2_extent_rec *insert_rec,
+                                 struct ocfs2_insert_type *type)
+{
+       int ret, rotate = 0;
+       u32 cpos;
+       struct ocfs2_path *right_path = NULL;
+       struct ocfs2_path *left_path = NULL;
+       struct ocfs2_extent_list *el;
+
+       el = et->et_root_el;
+
+       ret = ocfs2_et_root_journal_access(handle, et,
+                                          OCFS2_JOURNAL_ACCESS_WRITE);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       if (le16_to_cpu(el->l_tree_depth) == 0) {
+               ocfs2_insert_at_leaf(et, insert_rec, el, type);
+               goto out_update_clusters;
+       }
+
+       right_path = ocfs2_new_path_from_et(et);
+       if (!right_path) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       /*
+        * Determine the path to start with. Rotations need the
+        * rightmost path, everything else can go directly to the
+        * target leaf.
+        */
+       cpos = le32_to_cpu(insert_rec->e_cpos);
+       if (type->ins_appending == APPEND_NONE &&
+           type->ins_contig == CONTIG_NONE) {
+               rotate = 1;
+               cpos = UINT_MAX;
+       }
+
+       ret = ocfs2_find_path(et->et_ci, right_path, cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       /*
+        * Rotations and appends need special treatment - they modify
+        * parts of the tree's above them.
+        *
+        * Both might pass back a path immediate to the left of the
+        * one being inserted to. This will be cause
+        * ocfs2_insert_path() to modify the rightmost records of
+        * left_path to account for an edge insert.
+        *
+        * XXX: When modifying this code, keep in mind that an insert
+        * can wind up skipping both of these two special cases...
+        */
+       if (rotate) {
+               ret = ocfs2_rotate_tree_right(handle, et, type->ins_split,
+                                             le32_to_cpu(insert_rec->e_cpos),
+                                             right_path, &left_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               /*
+                * ocfs2_rotate_tree_right() might have extended the
+                * transaction without re-journaling our tree root.
+                */
+               ret = ocfs2_et_root_journal_access(handle, et,
+                                                  OCFS2_JOURNAL_ACCESS_WRITE);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       } else if (type->ins_appending == APPEND_TAIL
+                  && type->ins_contig != CONTIG_LEFT) {
+               ret = ocfs2_append_rec_to_path(handle, et, insert_rec,
+                                              right_path, &left_path);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       }
+
+       ret = ocfs2_insert_path(handle, et, left_path, right_path,
+                               insert_rec, type);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+out_update_clusters:
+       if (type->ins_split == SPLIT_NONE)
+               ocfs2_et_update_clusters(et,
+                                        le16_to_cpu(insert_rec->e_leaf_clusters));
+
+       ret = ocfs2_journal_dirty(handle, et->et_root_bh);
+       if (ret)
+               mlog_errno(ret);
+
+out:
+       ocfs2_free_path(left_path);
+       ocfs2_free_path(right_path);
+
+       return ret;
+}
+
+static enum ocfs2_contig_type
+ocfs2_figure_merge_contig_type(struct ocfs2_extent_tree *et,
+                              struct ocfs2_path *path,
+                              struct ocfs2_extent_list *el, int index,
+                              struct ocfs2_extent_rec *split_rec)
+{
+       int status;
+       enum ocfs2_contig_type ret = CONTIG_NONE;
+       u32 left_cpos, right_cpos;
+       struct ocfs2_extent_rec *rec = NULL;
+       struct ocfs2_extent_list *new_el;
+       struct ocfs2_path *left_path = NULL, *right_path = NULL;
+       struct buffer_head *bh;
+       struct ocfs2_extent_block *eb;
+       struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
+
+       if (index > 0) {
+               rec = &el->l_recs[index - 1];
+       } else if (path->p_tree_depth > 0) {
+               status = ocfs2_find_cpos_for_left_leaf(sb, path, &left_cpos);
+               if (status)
+                       goto out;
+
+               if (left_cpos != 0) {
+                       left_path = ocfs2_new_path_from_path(path);
+                       if (!left_path)
+                               goto out;
+
+                       status = ocfs2_find_path(et->et_ci, left_path,
+                                                left_cpos);
+                       if (status)
+                               goto out;
+
+                       new_el = path_leaf_el(left_path);
+
+                       if (le16_to_cpu(new_el->l_next_free_rec) !=
+                           le16_to_cpu(new_el->l_count)) {
+                               bh = path_leaf_bh(left_path);
+                               eb = (struct ocfs2_extent_block *)bh->b_data;
+                               ocfs2_error(sb,
+                                           "Extent block #%llu has an "
+                                           "invalid l_next_free_rec of "
+                                           "%d.  It should have "
+                                           "matched the l_count of %d",
+                                           (unsigned long long)le64_to_cpu(eb->h_blkno),
+                                           le16_to_cpu(new_el->l_next_free_rec),
+                                           le16_to_cpu(new_el->l_count));
+                               status = -EINVAL;
+                               goto out;
+                       }
+                       rec = &new_el->l_recs[
+                               le16_to_cpu(new_el->l_next_free_rec) - 1];
+               }
+       }
+
+       /*
+        * We're careful to check for an empty extent record here -
+        * the merge code will know what to do if it sees one.
+        */
+       if (rec) {
+               if (index == 1 && ocfs2_is_empty_extent(rec)) {
+                       if (split_rec->e_cpos == el->l_recs[index].e_cpos)
+                               ret = CONTIG_RIGHT;
+               } else {
+                       ret = ocfs2_et_extent_contig(et, rec, split_rec);
+               }
+       }
+
+       rec = NULL;
+       if (index < (le16_to_cpu(el->l_next_free_rec) - 1))
+               rec = &el->l_recs[index + 1];
+       else if (le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count) &&
+                path->p_tree_depth > 0) {
+               status = ocfs2_find_cpos_for_right_leaf(sb, path, &right_cpos);
+               if (status)
+                       goto out;
+
+               if (right_cpos == 0)
+                       goto out;
+
+               right_path = ocfs2_new_path_from_path(path);
+               if (!right_path)
+                       goto out;
+
+               status = ocfs2_find_path(et->et_ci, right_path, right_cpos);
+               if (status)
+                       goto out;
+
+               new_el = path_leaf_el(right_path);
+               rec = &new_el->l_recs[0];
+               if (ocfs2_is_empty_extent(rec)) {
+                       if (le16_to_cpu(new_el->l_next_free_rec) <= 1) {
+                               bh = path_leaf_bh(right_path);
+                               eb = (struct ocfs2_extent_block *)bh->b_data;
+                               ocfs2_error(sb,
+                                           "Extent block #%llu has an "
+                                           "invalid l_next_free_rec of %d",
+                                           (unsigned long long)le64_to_cpu(eb->h_blkno),
+                                           le16_to_cpu(new_el->l_next_free_rec));
+                               status = -EINVAL;
+                               goto out;
+                       }
+                       rec = &new_el->l_recs[1];
+               }
+       }
+
+       if (rec) {
+               enum ocfs2_contig_type contig_type;
+
+               contig_type = ocfs2_et_extent_contig(et, rec, split_rec);
+
+               if (contig_type == CONTIG_LEFT && ret == CONTIG_RIGHT)
+                       ret = CONTIG_LEFTRIGHT;
+               else if (ret == CONTIG_NONE)
+                       ret = contig_type;
+       }
+
+out:
+       if (left_path)
+               ocfs2_free_path(left_path);
+       if (right_path)
+               ocfs2_free_path(right_path);
+
+       return ret;
+}
+
+static void ocfs2_figure_contig_type(struct ocfs2_extent_tree *et,
+                                    struct ocfs2_insert_type *insert,
+                                    struct ocfs2_extent_list *el,
+                                    struct ocfs2_extent_rec *insert_rec)
+{
+       int i;
+       enum ocfs2_contig_type contig_type = CONTIG_NONE;
+
+       BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
+
+       for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
+               contig_type = ocfs2_et_extent_contig(et, &el->l_recs[i],
+                                                    insert_rec);
+               if (contig_type != CONTIG_NONE) {
+                       insert->ins_contig_index = i;
+                       break;
+               }
+       }
+       insert->ins_contig = contig_type;
+
+       if (insert->ins_contig != CONTIG_NONE) {
+               struct ocfs2_extent_rec *rec =
+                               &el->l_recs[insert->ins_contig_index];
+               unsigned int len = le16_to_cpu(rec->e_leaf_clusters) +
+                                  le16_to_cpu(insert_rec->e_leaf_clusters);
+
+               /*
+                * Caller might want us to limit the size of extents, don't
+                * calculate contiguousness if we might exceed that limit.
+                */
+               if (et->et_max_leaf_clusters &&
+                   (len > et->et_max_leaf_clusters))
+                       insert->ins_contig = CONTIG_NONE;
+       }
+}
+
+/*
+ * This should only be called against the righmost leaf extent list.
+ *
+ * ocfs2_figure_appending_type() will figure out whether we'll have to
+ * insert at the tail of the rightmost leaf.
+ *
+ * This should also work against the root extent list for tree's with 0
+ * depth. If we consider the root extent list to be the rightmost leaf node
+ * then the logic here makes sense.
+ */
+static void ocfs2_figure_appending_type(struct ocfs2_insert_type *insert,
+                                       struct ocfs2_extent_list *el,
+                                       struct ocfs2_extent_rec *insert_rec)
+{
+       int i;
+       u32 cpos = le32_to_cpu(insert_rec->e_cpos);
+       struct ocfs2_extent_rec *rec;
+
+       insert->ins_appending = APPEND_NONE;
+
+       BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
+
+       if (!el->l_next_free_rec)
+               goto set_tail_append;
+
+       if (ocfs2_is_empty_extent(&el->l_recs[0])) {
+               /* Were all records empty? */
+               if (le16_to_cpu(el->l_next_free_rec) == 1)
+                       goto set_tail_append;
+       }
+
+       i = le16_to_cpu(el->l_next_free_rec) - 1;
+       rec = &el->l_recs[i];
+
+       if (cpos >=
+           (le32_to_cpu(rec->e_cpos) + le16_to_cpu(rec->e_leaf_clusters)))
+               goto set_tail_append;
+
+       return;
+
+set_tail_append:
+       insert->ins_appending = APPEND_TAIL;
+}
+
+/*
+ * Helper function called at the begining of an insert.
+ *
+ * This computes a few things that are commonly used in the process of
+ * inserting into the btree:
+ *   - Whether the new extent is contiguous with an existing one.
+ *   - The current tree depth.
+ *   - Whether the insert is an appending one.
+ *   - The total # of free records in the tree.
+ *
+ * All of the information is stored on the ocfs2_insert_type
+ * structure.
+ */
+static int ocfs2_figure_insert_type(struct ocfs2_extent_tree *et,
+                                   struct buffer_head **last_eb_bh,
+                                   struct ocfs2_extent_rec *insert_rec,
+                                   int *free_records,
+                                   struct ocfs2_insert_type *insert)
+{
+       int ret;
+       struct ocfs2_extent_block *eb;
+       struct ocfs2_extent_list *el;
+       struct ocfs2_path *path = NULL;
+       struct buffer_head *bh = NULL;
+
+       insert->ins_split = SPLIT_NONE;
+
+       el = et->et_root_el;
+       insert->ins_tree_depth = le16_to_cpu(el->l_tree_depth);
+
+       if (el->l_tree_depth) {
+               /*
+                * If we have tree depth, we read in the
+                * rightmost extent block ahead of time as
+                * ocfs2_figure_insert_type() and ocfs2_add_branch()
+                * may want it later.
+                */
+               ret = ocfs2_read_extent_block(et->et_ci,
+                                             ocfs2_et_get_last_eb_blk(et),
+                                             &bh);
+               if (ret) {
+                       mlog_exit(ret);
+                       goto out;
+               }
+               eb = (struct ocfs2_extent_block *) bh->b_data;
+               el = &eb->h_list;
+       }
+
+       /*
+        * Unless we have a contiguous insert, we'll need to know if
+        * there is room left in our allocation tree for another
+        * extent record.
+        *
+        * XXX: This test is simplistic, we can search for empty
+        * extent records too.
+        */
+       *free_records = le16_to_cpu(el->l_count) -
+               le16_to_cpu(el->l_next_free_rec);
+
+       if (!insert->ins_tree_depth) {
+               ocfs2_figure_contig_type(et, insert, el, insert_rec);
+               ocfs2_figure_appending_type(insert, el, insert_rec);
+               return 0;
+       }
+
+       path = ocfs2_new_path_from_et(et);
+       if (!path) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       /*
+        * In the case that we're inserting past what the tree
+        * currently accounts for, ocfs2_find_path() will return for
+        * us the rightmost tree path. This is accounted for below in
+        * the appending code.
+        */
+       ret = ocfs2_find_path(et->et_ci, path, le32_to_cpu(insert_rec->e_cpos));
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       el = path_leaf_el(path);
+
+       /*
+        * Now that we have the path, there's two things we want to determine:
+        * 1) Contiguousness (also set contig_index if this is so)
+        *
+        * 2) Are we doing an append? We can trivially break this up
+         *     into two types of appends: simple record append, or a
+         *     rotate inside the tail leaf.
+        */
+       ocfs2_figure_contig_type(et, insert, el, insert_rec);
+
+       /*
+        * The insert code isn't quite ready to deal with all cases of
+        * left contiguousness. Specifically, if it's an insert into
+        * the 1st record in a leaf, it will require the adjustment of
+        * cluster count on the last record of the path directly to it's
+        * left. For now, just catch that case and fool the layers
+        * above us. This works just fine for tree_depth == 0, which
+        * is why we allow that above.
+        */
+       if (insert->ins_contig == CONTIG_LEFT &&
+           insert->ins_contig_index == 0)
+               insert->ins_contig = CONTIG_NONE;
+
+       /*
+        * Ok, so we can simply compare against last_eb to figure out
+        * whether the path doesn't exist. This will only happen in
+        * the case that we're doing a tail append, so maybe we can
+        * take advantage of that information somehow.
+        */
+       if (ocfs2_et_get_last_eb_blk(et) ==
+           path_leaf_bh(path)->b_blocknr) {
+               /*
+                * Ok, ocfs2_find_path() returned us the rightmost
+                * tree path. This might be an appending insert. There are
+                * two cases:
+                *    1) We're doing a true append at the tail:
+                *      -This might even be off the end of the leaf
+                *    2) We're "appending" by rotating in the tail
+                */
+               ocfs2_figure_appending_type(insert, el, insert_rec);
+       }
+
+out:
+       ocfs2_free_path(path);
+
+       if (ret == 0)
+               *last_eb_bh = bh;
+       else
+               brelse(bh);
+       return ret;
+}
+
+/*
+ * Insert an extent into a btree.
+ *
+ * The caller needs to update the owning btree's cluster count.
+ */
+int ocfs2_insert_extent(handle_t *handle,
+                       struct ocfs2_extent_tree *et,
+                       u32 cpos,
+                       u64 start_blk,
+                       u32 new_clusters,
+                       u8 flags,
+                       struct ocfs2_alloc_context *meta_ac)
+{
+       int status;
+       int uninitialized_var(free_records);
+       struct buffer_head *last_eb_bh = NULL;
+       struct ocfs2_insert_type insert = {0, };
+       struct ocfs2_extent_rec rec;
+
+       mlog(0, "add %u clusters at position %u to owner %llu\n",
+            new_clusters, cpos,
+            (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci));
+
+       memset(&rec, 0, sizeof(rec));
+       rec.e_cpos = cpu_to_le32(cpos);
+       rec.e_blkno = cpu_to_le64(start_blk);
+       rec.e_leaf_clusters = cpu_to_le16(new_clusters);
+       rec.e_flags = flags;
+       status = ocfs2_et_insert_check(et, &rec);
+       if (status) {
+               mlog_errno(status);
+               goto bail;
+       }
+
+       status = ocfs2_figure_insert_type(et, &last_eb_bh, &rec,
+                                         &free_records, &insert);
+       if (status < 0) {
+               mlog_errno(status);
+               goto bail;
+       }
+
+       mlog(0, "Insert.appending: %u, Insert.Contig: %u, "
+            "Insert.contig_index: %d, Insert.free_records: %d, "
+            "Insert.tree_depth: %d\n",
+            insert.ins_appending, insert.ins_contig, insert.ins_contig_index,
+            free_records, insert.ins_tree_depth);
+
+       if (insert.ins_contig == CONTIG_NONE && free_records == 0) {
+               status = ocfs2_grow_tree(handle, et,
+                                        &insert.ins_tree_depth, &last_eb_bh,
+                                        meta_ac);
+               if (status) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+       }
+
+       /* Finally, we can add clusters. This might rotate the tree for us. */
+       status = ocfs2_do_insert_extent(handle, et, &rec, &insert);
+       if (status < 0)
+               mlog_errno(status);
+       else
+               ocfs2_et_extent_map_insert(et, &rec);
+
+bail:
+       brelse(last_eb_bh);
+
+       mlog_exit(status);
+       return status;
+}
+
+/*
+ * Allcate and add clusters into the extent b-tree.
+ * The new clusters(clusters_to_add) will be inserted at logical_offset.
+ * The extent b-tree's root is specified by et, and
+ * it is not limited to the file storage. Any extent tree can use this
+ * function if it implements the proper ocfs2_extent_tree.
+ */
+int ocfs2_add_clusters_in_btree(handle_t *handle,
+                               struct ocfs2_extent_tree *et,
+                               u32 *logical_offset,
+                               u32 clusters_to_add,
+                               int mark_unwritten,
+                               struct ocfs2_alloc_context *data_ac,
+                               struct ocfs2_alloc_context *meta_ac,
+                               enum ocfs2_alloc_restarted *reason_ret)
+{
+       int status = 0;
+       int free_extents;
+       enum ocfs2_alloc_restarted reason = RESTART_NONE;
+       u32 bit_off, num_bits;
+       u64 block;
+       u8 flags = 0;
+       struct ocfs2_super *osb =
+               OCFS2_SB(ocfs2_metadata_cache_get_super(et->et_ci));
+
+       BUG_ON(!clusters_to_add);
+
+       if (mark_unwritten)
+               flags = OCFS2_EXT_UNWRITTEN;
+
+       free_extents = ocfs2_num_free_extents(osb, et);
+       if (free_extents < 0) {
+               status = free_extents;
+               mlog_errno(status);
+               goto leave;
+       }
+
+       /* there are two cases which could cause us to EAGAIN in the
+        * we-need-more-metadata case:
+        * 1) we haven't reserved *any*
+        * 2) we are so fragmented, we've needed to add metadata too
+        *    many times. */
+       if (!free_extents && !meta_ac) {
+               mlog(0, "we haven't reserved any metadata!\n");
+               status = -EAGAIN;
+               reason = RESTART_META;
+               goto leave;
+       } else if ((!free_extents)
+                  && (ocfs2_alloc_context_bits_left(meta_ac)
+                      < ocfs2_extend_meta_needed(et->et_root_el))) {
+               mlog(0, "filesystem is really fragmented...\n");
+               status = -EAGAIN;
+               reason = RESTART_META;
+               goto leave;
+       }
+
+       status = __ocfs2_claim_clusters(osb, handle, data_ac, 1,
+                                       clusters_to_add, &bit_off, &num_bits);
+       if (status < 0) {
+               if (status != -ENOSPC)
+                       mlog_errno(status);
+               goto leave;
+       }
+
+       BUG_ON(num_bits > clusters_to_add);
+
+       /* reserve our write early -- insert_extent may update the tree root */
+       status = ocfs2_et_root_journal_access(handle, et,
+                                             OCFS2_JOURNAL_ACCESS_WRITE);
+       if (status < 0) {
+               mlog_errno(status);
+               goto leave;
+       }
+
+       block = ocfs2_clusters_to_blocks(osb->sb, bit_off);
+       mlog(0, "Allocating %u clusters at block %u for owner %llu\n",
+            num_bits, bit_off,
+            (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci));
+       status = ocfs2_insert_extent(handle, et, *logical_offset, block,
+                                    num_bits, flags, meta_ac);
+       if (status < 0) {
+               mlog_errno(status);
+               goto leave;
+       }
+
+       status = ocfs2_journal_dirty(handle, et->et_root_bh);
+       if (status < 0) {
+               mlog_errno(status);
+               goto leave;
+       }
+
+       clusters_to_add -= num_bits;
+       *logical_offset += num_bits;
+
+       if (clusters_to_add) {
+               mlog(0, "need to alloc once more, wanted = %u\n",
+                    clusters_to_add);
+               status = -EAGAIN;
+               reason = RESTART_TRANS;
+       }
+
+leave:
+       mlog_exit(status);
+       if (reason_ret)
+               *reason_ret = reason;
+       return status;
+}
+
+static void ocfs2_make_right_split_rec(struct super_block *sb,
+                                      struct ocfs2_extent_rec *split_rec,
+                                      u32 cpos,
+                                      struct ocfs2_extent_rec *rec)
+{
+       u32 rec_cpos = le32_to_cpu(rec->e_cpos);
+       u32 rec_range = rec_cpos + le16_to_cpu(rec->e_leaf_clusters);
+
+       memset(split_rec, 0, sizeof(struct ocfs2_extent_rec));
+
+       split_rec->e_cpos = cpu_to_le32(cpos);
+       split_rec->e_leaf_clusters = cpu_to_le16(rec_range - cpos);
+
+       split_rec->e_blkno = rec->e_blkno;
+       le64_add_cpu(&split_rec->e_blkno,
+                    ocfs2_clusters_to_blocks(sb, cpos - rec_cpos));
+
+       split_rec->e_flags = rec->e_flags;
+}
+
+static int ocfs2_split_and_insert(handle_t *handle,
+                                 struct ocfs2_extent_tree *et,
+                                 struct ocfs2_path *path,
+                                 struct buffer_head **last_eb_bh,
+                                 int split_index,
+                                 struct ocfs2_extent_rec *orig_split_rec,
+                                 struct ocfs2_alloc_context *meta_ac)
+{
+       int ret = 0, depth;
+       unsigned int insert_range, rec_range, do_leftright = 0;
+       struct ocfs2_extent_rec tmprec;
+       struct ocfs2_extent_list *rightmost_el;
+       struct ocfs2_extent_rec rec;
+       struct ocfs2_extent_rec split_rec = *orig_split_rec;
+       struct ocfs2_insert_type insert;
+       struct ocfs2_extent_block *eb;
+
+leftright:
+       /*
+        * Store a copy of the record on the stack - it might move
+        * around as the tree is manipulated below.
+        */
+       rec = path_leaf_el(path)->l_recs[split_index];
+
+       rightmost_el = et->et_root_el;
+
+       depth = le16_to_cpu(rightmost_el->l_tree_depth);
+       if (depth) {
+               BUG_ON(!(*last_eb_bh));
+               eb = (struct ocfs2_extent_block *) (*last_eb_bh)->b_data;
+               rightmost_el = &eb->h_list;
+       }
+
+       if (le16_to_cpu(rightmost_el->l_next_free_rec) ==
+           le16_to_cpu(rightmost_el->l_count)) {
+               ret = ocfs2_grow_tree(handle, et,
+                                     &depth, last_eb_bh, meta_ac);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       }
+
+       memset(&insert, 0, sizeof(struct ocfs2_insert_type));
+       insert.ins_appending = APPEND_NONE;
+       insert.ins_contig = CONTIG_NONE;
+       insert.ins_tree_depth = depth;
+
+       insert_range = le32_to_cpu(split_rec.e_cpos) +
+               le16_to_cpu(split_rec.e_leaf_clusters);
+       rec_range = le32_to_cpu(rec.e_cpos) +
+               le16_to_cpu(rec.e_leaf_clusters);
+
+       if (split_rec.e_cpos == rec.e_cpos) {
+               insert.ins_split = SPLIT_LEFT;
+       } else if (insert_range == rec_range) {
+               insert.ins_split = SPLIT_RIGHT;
+       } else {
+               /*
+                * Left/right split. We fake this as a right split
+                * first and then make a second pass as a left split.
+                */
+               insert.ins_split = SPLIT_RIGHT;
+
+               ocfs2_make_right_split_rec(ocfs2_metadata_cache_get_super(et->et_ci),
+                                          &tmprec, insert_range, &rec);
+
+               split_rec = tmprec;
+
+               BUG_ON(do_leftright);
+               do_leftright = 1;
+       }
+
+       ret = ocfs2_do_insert_extent(handle, et, &split_rec, &insert);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       if (do_leftright == 1) {
+               u32 cpos;
+               struct ocfs2_extent_list *el;
+
+               do_leftright++;
+               split_rec = *orig_split_rec;
+
+               ocfs2_reinit_path(path, 1);
+
+               cpos = le32_to_cpu(split_rec.e_cpos);
+               ret = ocfs2_find_path(et->et_ci, path, cpos);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               el = path_leaf_el(path);
+               split_index = ocfs2_search_extent_list(el, cpos);
+               goto leftright;
+       }
+out:
+
+       return ret;
+}
+
+static int ocfs2_replace_extent_rec(handle_t *handle,
+                                   struct ocfs2_extent_tree *et,
+                                   struct ocfs2_path *path,
+                                   struct ocfs2_extent_list *el,
+                                   int split_index,
+                                   struct ocfs2_extent_rec *split_rec)
+{
+       int ret;
+
+       ret = ocfs2_path_bh_journal_access(handle, et->et_ci, path,
+                                          path_num_items(path) - 1);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       el->l_recs[split_index] = *split_rec;
+
+       ocfs2_journal_dirty(handle, path_leaf_bh(path));
+out:
+       return ret;
+}
+
+/*
+ * Split part or all of the extent record at split_index in the leaf
+ * pointed to by path. Merge with the contiguous extent record if needed.
+ *
+ * Care is taken to handle contiguousness so as to not grow the tree.
+ *
+ * meta_ac is not strictly necessary - we only truly need it if growth
+ * of the tree is required. All other cases will degrade into a less
+ * optimal tree layout.
+ *
+ * last_eb_bh should be the rightmost leaf block for any extent
+ * btree. Since a split may grow the tree or a merge might shrink it,
+ * the caller cannot trust the contents of that buffer after this call.
+ *
+ * This code is optimized for readability - several passes might be
+ * made over certain portions of the tree. All of those blocks will
+ * have been brought into cache (and pinned via the journal), so the
+ * extra overhead is not expressed in terms of disk reads.
+ */
+int ocfs2_split_extent(handle_t *handle,
+                      struct ocfs2_extent_tree *et,
+                      struct ocfs2_path *path,
+                      int split_index,
+                      struct ocfs2_extent_rec *split_rec,
+                      struct ocfs2_alloc_context *meta_ac,
+                      struct ocfs2_cached_dealloc_ctxt *dealloc)
+{
+       int ret = 0;
+       struct ocfs2_extent_list *el = path_leaf_el(path);
+       struct buffer_head *last_eb_bh = NULL;
+       struct ocfs2_extent_rec *rec = &el->l_recs[split_index];
+       struct ocfs2_merge_ctxt ctxt;
+       struct ocfs2_extent_list *rightmost_el;
+
+       if (le32_to_cpu(rec->e_cpos) > le32_to_cpu(split_rec->e_cpos) ||
+           ((le32_to_cpu(rec->e_cpos) + le16_to_cpu(rec->e_leaf_clusters)) <
+            (le32_to_cpu(split_rec->e_cpos) + le16_to_cpu(split_rec->e_leaf_clusters)))) {
+               ret = -EIO;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ctxt.c_contig_type = ocfs2_figure_merge_contig_type(et, path, el,
+                                                           split_index,
+                                                           split_rec);
+
+       /*
+        * The core merge / split code wants to know how much room is
+        * left in this allocation tree, so we pass the
+        * rightmost extent list.
+        */
+       if (path->p_tree_depth) {
+               struct ocfs2_extent_block *eb;
+
+               ret = ocfs2_read_extent_block(et->et_ci,
+                                             ocfs2_et_get_last_eb_blk(et),
+                                             &last_eb_bh);
+               if (ret) {
+                       mlog_exit(ret);
+                       goto out;
+               }
+
+               eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+               rightmost_el = &eb->h_list;
+       } else
+               rightmost_el = path_root_el(path);
+
+       if (rec->e_cpos == split_rec->e_cpos &&
+           rec->e_leaf_clusters == split_rec->e_leaf_clusters)
+               ctxt.c_split_covers_rec = 1;
+       else
+               ctxt.c_split_covers_rec = 0;
+
+       ctxt.c_has_empty_extent = ocfs2_is_empty_extent(&el->l_recs[0]);
+
+       mlog(0, "index: %d, contig: %u, has_empty: %u, split_covers: %u\n",
+            split_index, ctxt.c_contig_type, ctxt.c_has_empty_extent,
+            ctxt.c_split_covers_rec);
+
+       if (ctxt.c_contig_type == CONTIG_NONE) {
+               if (ctxt.c_split_covers_rec)
+                       ret = ocfs2_replace_extent_rec(handle, et, path, el,
+                                                      split_index, split_rec);
+               else
+                       ret = ocfs2_split_and_insert(handle, et, path,
+                                                    &last_eb_bh, split_index,
+                                                    split_rec, meta_ac);
+               if (ret)
+                       mlog_errno(ret);
+       } else {
+               ret = ocfs2_try_to_merge_extent(handle, et, path,
+                                               split_index, split_rec,
+                                               dealloc, &ctxt);
+               if (ret)
+                       mlog_errno(ret);
+       }
+
+out:
+       brelse(last_eb_bh);
+       return ret;
+}
+
+/*
+ * Change the flags of the already-existing extent at cpos for len clusters.
+ *
+ * new_flags: the flags we want to set.
+ * clear_flags: the flags we want to clear.
+ * phys: the new physical offset we want this new extent starts from.
+ *
+ * If the existing extent is larger than the request, initiate a
+ * split. An attempt will be made at merging with adjacent extents.
+ *
+ * The caller is responsible for passing down meta_ac if we'll need it.
+ */
+int ocfs2_change_extent_flag(handle_t *handle,
+                            struct ocfs2_extent_tree *et,
+                            u32 cpos, u32 len, u32 phys,
+                            struct ocfs2_alloc_context *meta_ac,
+                            struct ocfs2_cached_dealloc_ctxt *dealloc,
+                            int new_flags, int clear_flags)
+{
+       int ret, index;
+       struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
+       u64 start_blkno = ocfs2_clusters_to_blocks(sb, phys);
+       struct ocfs2_extent_rec split_rec;
+       struct ocfs2_path *left_path = NULL;
+       struct ocfs2_extent_list *el;
+       struct ocfs2_extent_rec *rec;
+
+       left_path = ocfs2_new_path_from_et(et);
+       if (!left_path) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ret = ocfs2_find_path(et->et_ci, left_path, cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+       el = path_leaf_el(left_path);
+
+       index = ocfs2_search_extent_list(el, cpos);
+       if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
+               ocfs2_error(sb,
+                           "Owner %llu has an extent at cpos %u which can no "
+                           "longer be found.\n",
+                            (unsigned long long)
+                            ocfs2_metadata_cache_owner(et->et_ci), cpos);
+               ret = -EROFS;
+               goto out;
+       }
+
+       ret = -EIO;
+       rec = &el->l_recs[index];
+       if (new_flags && (rec->e_flags & new_flags)) {
+               mlog(ML_ERROR, "Owner %llu tried to set %d flags on an "
+                    "extent that already had them",
+                    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                    new_flags);
+               goto out;
+       }
+
+       if (clear_flags && !(rec->e_flags & clear_flags)) {
+               mlog(ML_ERROR, "Owner %llu tried to clear %d flags on an "
+                    "extent that didn't have them",
+                    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                    clear_flags);
+               goto out;
+       }
+
+       memset(&split_rec, 0, sizeof(struct ocfs2_extent_rec));
+       split_rec.e_cpos = cpu_to_le32(cpos);
+       split_rec.e_leaf_clusters = cpu_to_le16(len);
+       split_rec.e_blkno = cpu_to_le64(start_blkno);
+       split_rec.e_flags = rec->e_flags;
+       if (new_flags)
+               split_rec.e_flags |= new_flags;
+       if (clear_flags)
+               split_rec.e_flags &= ~clear_flags;
+
+       ret = ocfs2_split_extent(handle, et, left_path,
+                                index, &split_rec, meta_ac,
+                                dealloc);
+       if (ret)
+               mlog_errno(ret);
+
+out:
+       ocfs2_free_path(left_path);
+       return ret;
+
+}
+
+/*
+ * Mark the already-existing extent at cpos as written for len clusters.
+ * This removes the unwritten extent flag.
+ *
+ * If the existing extent is larger than the request, initiate a
+ * split. An attempt will be made at merging with adjacent extents.
+ *
+ * The caller is responsible for passing down meta_ac if we'll need it.
+ */
+int ocfs2_mark_extent_written(struct inode *inode,
+                             struct ocfs2_extent_tree *et,
+                             handle_t *handle, u32 cpos, u32 len, u32 phys,
+                             struct ocfs2_alloc_context *meta_ac,
+                             struct ocfs2_cached_dealloc_ctxt *dealloc)
+{
+       int ret;
+
+       mlog(0, "Inode %lu cpos %u, len %u, phys clusters %u\n",
+            inode->i_ino, cpos, len, phys);
+
+       if (!ocfs2_writes_unwritten_extents(OCFS2_SB(inode->i_sb))) {
+               ocfs2_error(inode->i_sb, "Inode %llu has unwritten extents "
+                           "that are being written to, but the feature bit "
+                           "is not set in the super block.",
+                           (unsigned long long)OCFS2_I(inode)->ip_blkno);
+               ret = -EROFS;
+               goto out;
+       }
+
+       /*
+        * XXX: This should be fixed up so that we just re-insert the
+        * next extent records.
+        */
+       ocfs2_et_extent_map_truncate(et, 0);
+
+       ret = ocfs2_change_extent_flag(handle, et, cpos,
+                                      len, phys, meta_ac, dealloc,
+                                      0, OCFS2_EXT_UNWRITTEN);
+       if (ret)
+               mlog_errno(ret);
+
+out:
+       return ret;
+}
+
+static int ocfs2_split_tree(handle_t *handle, struct ocfs2_extent_tree *et,
+                           struct ocfs2_path *path,
+                           int index, u32 new_range,
+                           struct ocfs2_alloc_context *meta_ac)
+{
+       int ret, depth, credits = handle->h_buffer_credits;
+       struct buffer_head *last_eb_bh = NULL;
+       struct ocfs2_extent_block *eb;
+       struct ocfs2_extent_list *rightmost_el, *el;
+       struct ocfs2_extent_rec split_rec;
+       struct ocfs2_extent_rec *rec;
+       struct ocfs2_insert_type insert;
+
+       /*
+        * Setup the record to split before we grow the tree.
+        */
+       el = path_leaf_el(path);
+       rec = &el->l_recs[index];
+       ocfs2_make_right_split_rec(ocfs2_metadata_cache_get_super(et->et_ci),
+                                  &split_rec, new_range, rec);
+
+       depth = path->p_tree_depth;
+       if (depth > 0) {
+               ret = ocfs2_read_extent_block(et->et_ci,
+                                             ocfs2_et_get_last_eb_blk(et),
+                                             &last_eb_bh);
+               if (ret < 0) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+               rightmost_el = &eb->h_list;
+       } else
+               rightmost_el = path_leaf_el(path);
+
+       credits += path->p_tree_depth +
+                  ocfs2_extend_meta_needed(et->et_root_el);
+       ret = ocfs2_extend_trans(handle, credits);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       if (le16_to_cpu(rightmost_el->l_next_free_rec) ==
+           le16_to_cpu(rightmost_el->l_count)) {
+               ret = ocfs2_grow_tree(handle, et, &depth, &last_eb_bh,
+                                     meta_ac);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       }
+
+       memset(&insert, 0, sizeof(struct ocfs2_insert_type));
+       insert.ins_appending = APPEND_NONE;
+       insert.ins_contig = CONTIG_NONE;
+       insert.ins_split = SPLIT_RIGHT;
+       insert.ins_tree_depth = depth;
+
+       ret = ocfs2_do_insert_extent(handle, et, &split_rec, &insert);
+       if (ret)
+               mlog_errno(ret);
+
+out:
+       brelse(last_eb_bh);
+       return ret;
+}
+
+static int ocfs2_truncate_rec(handle_t *handle,
+                             struct ocfs2_extent_tree *et,
+                             struct ocfs2_path *path, int index,
+                             struct ocfs2_cached_dealloc_ctxt *dealloc,
+                             u32 cpos, u32 len)
+{
+       int ret;
+       u32 left_cpos, rec_range, trunc_range;
+       int wants_rotate = 0, is_rightmost_tree_rec = 0;
+       struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci);
+       struct ocfs2_path *left_path = NULL;
+       struct ocfs2_extent_list *el = path_leaf_el(path);
+       struct ocfs2_extent_rec *rec;
+       struct ocfs2_extent_block *eb;
+
+       if (ocfs2_is_empty_extent(&el->l_recs[0]) && index > 0) {
+               ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               index--;
+       }
+
+       if (index == (le16_to_cpu(el->l_next_free_rec) - 1) &&
+           path->p_tree_depth) {
+               /*
+                * Check whether this is the rightmost tree record. If
+                * we remove all of this record or part of its right
+                * edge then an update of the record lengths above it
+                * will be required.
+                */
+               eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
+               if (eb->h_next_leaf_blk == 0)
+                       is_rightmost_tree_rec = 1;
+       }
+
+       rec = &el->l_recs[index];
+       if (index == 0 && path->p_tree_depth &&
+           le32_to_cpu(rec->e_cpos) == cpos) {
+               /*
+                * Changing the leftmost offset (via partial or whole
+                * record truncate) of an interior (or rightmost) path
+                * means we have to update the subtree that is formed
+                * by this leaf and the one to it's left.
+                *
+                * There are two cases we can skip:
+                *   1) Path is the leftmost one in our btree.
+                *   2) The leaf is rightmost and will be empty after
+                *      we remove the extent record - the rotate code
+                *      knows how to update the newly formed edge.
+                */
+
+               ret = ocfs2_find_cpos_for_left_leaf(sb, path, &left_cpos);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               if (left_cpos && le16_to_cpu(el->l_next_free_rec) > 1) {
+                       left_path = ocfs2_new_path_from_path(path);
+                       if (!left_path) {
+                               ret = -ENOMEM;
+                               mlog_errno(ret);
+                               goto out;
+                       }
+
+                       ret = ocfs2_find_path(et->et_ci, left_path,
+                                             left_cpos);
+                       if (ret) {
+                               mlog_errno(ret);
+                               goto out;
+                       }
+               }
+       }
+
+       ret = ocfs2_extend_rotate_transaction(handle, 0,
+                                             handle->h_buffer_credits,
+                                             path);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ret = ocfs2_journal_access_path(et->et_ci, handle, path);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ret = ocfs2_journal_access_path(et->et_ci, handle, left_path);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       rec_range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
+       trunc_range = cpos + len;
+
+       if (le32_to_cpu(rec->e_cpos) == cpos && rec_range == trunc_range) {
+               int next_free;
+
+               memset(rec, 0, sizeof(*rec));
+               ocfs2_cleanup_merge(el, index);
+               wants_rotate = 1;
+
+               next_free = le16_to_cpu(el->l_next_free_rec);
+               if (is_rightmost_tree_rec && next_free > 1) {
+                       /*
+                        * We skip the edge update if this path will
+                        * be deleted by the rotate code.
+                        */
+                       rec = &el->l_recs[next_free - 1];
+                       ocfs2_adjust_rightmost_records(handle, et, path,
+                                                      rec);
+               }
+       } else if (le32_to_cpu(rec->e_cpos) == cpos) {
+               /* Remove leftmost portion of the record. */
+               le32_add_cpu(&rec->e_cpos, len);
+               le64_add_cpu(&rec->e_blkno, ocfs2_clusters_to_blocks(sb, len));
+               le16_add_cpu(&rec->e_leaf_clusters, -len);
+       } else if (rec_range == trunc_range) {
+               /* Remove rightmost portion of the record */
+               le16_add_cpu(&rec->e_leaf_clusters, -len);
+               if (is_rightmost_tree_rec)
+                       ocfs2_adjust_rightmost_records(handle, et, path, rec);
+       } else {
+               /* Caller should have trapped this. */
+               mlog(ML_ERROR, "Owner %llu: Invalid record truncate: (%u, %u) "
+                    "(%u, %u)\n",
+                    (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                    le32_to_cpu(rec->e_cpos),
+                    le16_to_cpu(rec->e_leaf_clusters), cpos, len);
+               BUG();
+       }
+
+       if (left_path) {
+               int subtree_index;
+
+               subtree_index = ocfs2_find_subtree_root(et, left_path, path);
+               ocfs2_complete_edge_insert(handle, left_path, path,
+                                          subtree_index);
+       }
+
+       ocfs2_journal_dirty(handle, path_leaf_bh(path));
+
+       ret = ocfs2_rotate_tree_left(handle, et, path, dealloc);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+out:
+       ocfs2_free_path(left_path);
+       return ret;
+}
+
+int ocfs2_remove_extent(handle_t *handle,
+                       struct ocfs2_extent_tree *et,
+                       u32 cpos, u32 len,
+                       struct ocfs2_alloc_context *meta_ac,
+                       struct ocfs2_cached_dealloc_ctxt *dealloc)
+{
+       int ret, index;
+       u32 rec_range, trunc_range;
+       struct ocfs2_extent_rec *rec;
+       struct ocfs2_extent_list *el;
+       struct ocfs2_path *path = NULL;
+
+       /*
+        * XXX: Why are we truncating to 0 instead of wherever this
+        * affects us?
+        */
+       ocfs2_et_extent_map_truncate(et, 0);
+
+       path = ocfs2_new_path_from_et(et);
+       if (!path) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ret = ocfs2_find_path(et->et_ci, path, cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       el = path_leaf_el(path);
+       index = ocfs2_search_extent_list(el, cpos);
+       if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
+               ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
+                           "Owner %llu has an extent at cpos %u which can no "
+                           "longer be found.\n",
+                           (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                           cpos);
+               ret = -EROFS;
+               goto out;
+       }
+
+       /*
+        * We have 3 cases of extent removal:
+        *   1) Range covers the entire extent rec
+        *   2) Range begins or ends on one edge of the extent rec
+        *   3) Range is in the middle of the extent rec (no shared edges)
+        *
+        * For case 1 we remove the extent rec and left rotate to
+        * fill the hole.
+        *
+        * For case 2 we just shrink the existing extent rec, with a
+        * tree update if the shrinking edge is also the edge of an
+        * extent block.
+        *
+        * For case 3 we do a right split to turn the extent rec into
+        * something case 2 can handle.
+        */
+       rec = &el->l_recs[index];
+       rec_range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
+       trunc_range = cpos + len;
+
+       BUG_ON(cpos < le32_to_cpu(rec->e_cpos) || trunc_range > rec_range);
+
+       mlog(0, "Owner %llu, remove (cpos %u, len %u). Existing index %d "
+            "(cpos %u, len %u)\n",
+            (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+            cpos, len, index,
+            le32_to_cpu(rec->e_cpos), ocfs2_rec_clusters(el, rec));
+
+       if (le32_to_cpu(rec->e_cpos) == cpos || rec_range == trunc_range) {
+               ret = ocfs2_truncate_rec(handle, et, path, index, dealloc,
+                                        cpos, len);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       } else {
+               ret = ocfs2_split_tree(handle, et, path, index,
+                                      trunc_range, meta_ac);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               /*
+                * The split could have manipulated the tree enough to
+                * move the record location, so we have to look for it again.
+                */
+               ocfs2_reinit_path(path, 1);
+
+               ret = ocfs2_find_path(et->et_ci, path, cpos);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               el = path_leaf_el(path);
+               index = ocfs2_search_extent_list(el, cpos);
+               if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
+                       ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
+                                   "Owner %llu: split at cpos %u lost record.",
+                                   (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                                   cpos);
+                       ret = -EROFS;
+                       goto out;
+               }
+
+               /*
+                * Double check our values here. If anything is fishy,
+                * it's easier to catch it at the top level.
+                */
+               rec = &el->l_recs[index];
+               rec_range = le32_to_cpu(rec->e_cpos) +
+                       ocfs2_rec_clusters(el, rec);
+               if (rec_range != trunc_range) {
+                       ocfs2_error(ocfs2_metadata_cache_get_super(et->et_ci),
+                                   "Owner %llu: error after split at cpos %u"
+                                   "trunc len %u, existing record is (%u,%u)",
+                                   (unsigned long long)ocfs2_metadata_cache_owner(et->et_ci),
+                                   cpos, len, le32_to_cpu(rec->e_cpos),
+                                   ocfs2_rec_clusters(el, rec));
+                       ret = -EROFS;
+                       goto out;
+               }
+
+               ret = ocfs2_truncate_rec(handle, et, path, index, dealloc,
+                                        cpos, len);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       }
+
+out:
+       ocfs2_free_path(path);
+       return ret;
+}
+
+int ocfs2_remove_btree_range(struct inode *inode,
+                            struct ocfs2_extent_tree *et,
+                            u32 cpos, u32 phys_cpos, u32 len,
+                            struct ocfs2_cached_dealloc_ctxt *dealloc)
+{
+       int ret;
+       u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+       struct inode *tl_inode = osb->osb_tl_inode;
+       handle_t *handle;
+       struct ocfs2_alloc_context *meta_ac = NULL;
+
+       ret = ocfs2_lock_allocators(inode, et, 0, 1, NULL, &meta_ac);
+       if (ret) {
+               mlog_errno(ret);
+               return ret;
+       }
+
+       mutex_lock(&tl_inode->i_mutex);
+
+       if (ocfs2_truncate_log_needs_flush(osb)) {
+               ret = __ocfs2_flush_truncate_log(osb);
+               if (ret < 0) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+       }
+
+       handle = ocfs2_start_trans(osb, ocfs2_remove_extent_credits(osb->sb));
+       if (IS_ERR(handle)) {
+               ret = PTR_ERR(handle);
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ret = ocfs2_et_root_journal_access(handle, et,
+                                          OCFS2_JOURNAL_ACCESS_WRITE);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       vfs_dq_free_space_nodirty(inode,
+                                 ocfs2_clusters_to_bytes(inode->i_sb, len));
+
+       ret = ocfs2_remove_extent(handle, et, cpos, len, meta_ac, dealloc);
+       if (ret) {
+               mlog_errno(ret);
+               goto out_commit;
+       }
+
+       ocfs2_et_update_clusters(et, -len);
+
+       ret = ocfs2_journal_dirty(handle, et->et_root_bh);
+       if (ret) {
+               mlog_errno(ret);
+               goto out_commit;
+       }
+
+       ret = ocfs2_truncate_log_append(osb, handle, phys_blkno, len);
+       if (ret)
+               mlog_errno(ret);
+
+out_commit:
+       ocfs2_commit_trans(osb, handle);
+out:
+       mutex_unlock(&tl_inode->i_mutex);
+
+       if (meta_ac)
+               ocfs2_free_alloc_context(meta_ac);
+
+       return ret;
+}
+
+int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb)
+{
+       struct buffer_head *tl_bh = osb->osb_tl_bh;
+       struct ocfs2_dinode *di;
+       struct ocfs2_truncate_log *tl;
+
+       di = (struct ocfs2_dinode *) tl_bh->b_data;
+       tl = &di->id2.i_dealloc;
+
+       mlog_bug_on_msg(le16_to_cpu(tl->tl_used) > le16_to_cpu(tl->tl_count),
+                       "slot %d, invalid truncate log parameters: used = "
+                       "%u, count = %u\n", osb->slot_num,
+                       le16_to_cpu(tl->tl_used), le16_to_cpu(tl->tl_count));
+       return le16_to_cpu(tl->tl_used) == le16_to_cpu(tl->tl_count);
+}
+
+static int ocfs2_truncate_log_can_coalesce(struct ocfs2_truncate_log *tl,
+                                          unsigned int new_start)
+{
+       unsigned int tail_index;
+       unsigned int current_tail;
+
+       /* No records, nothing to coalesce */
+       if (!le16_to_cpu(tl->tl_used))
+               return 0;
+
+       tail_index = le16_to_cpu(tl->tl_used) - 1;
+       current_tail = le32_to_cpu(tl->tl_recs[tail_index].t_start);
+       current_tail += le32_to_cpu(tl->tl_recs[tail_index].t_clusters);
+
+       return current_tail == new_start;
+}
+
+int ocfs2_truncate_log_append(struct ocfs2_super *osb,
+                             handle_t *handle,
+                             u64 start_blk,
+                             unsigned int num_clusters)
+{
+       int status, index;
+       unsigned int start_cluster, tl_count;
+       struct inode *tl_inode = osb->osb_tl_inode;
+       struct buffer_head *tl_bh = osb->osb_tl_bh;
+       struct ocfs2_dinode *di;
+       struct ocfs2_truncate_log *tl;
+
+       mlog_entry("start_blk = %llu, num_clusters = %u\n",
+                  (unsigned long long)start_blk, num_clusters);
+
+       BUG_ON(mutex_trylock(&tl_inode->i_mutex));
+
+       start_cluster = ocfs2_blocks_to_clusters(osb->sb, start_blk);
+
+       di = (struct ocfs2_dinode *) tl_bh->b_data;
+
+       /* tl_bh is loaded from ocfs2_truncate_log_init().  It's validated
+        * by the underlying call to ocfs2_read_inode_block(), so any
+        * corruption is a code bug */
+       BUG_ON(!OCFS2_IS_VALID_DINODE(di));
+
+       tl = &di->id2.i_dealloc;
+       tl_count = le16_to_cpu(tl->tl_count);
+       mlog_bug_on_msg(tl_count > ocfs2_truncate_recs_per_inode(osb->sb) ||
+                       tl_count == 0,
+                       "Truncate record count on #%llu invalid "
+                       "wanted %u, actual %u\n",
+                       (unsigned long long)OCFS2_I(tl_inode)->ip_blkno,
+                       ocfs2_truncate_recs_per_inode(osb->sb),
+                       le16_to_cpu(tl->tl_count));
+
+       /* Caller should have known to flush before calling us. */
+       index = le16_to_cpu(tl->tl_used);
+       if (index >= tl_count) {
+               status = -ENOSPC;
+               mlog_errno(status);
+               goto bail;
+       }
+
+       status = ocfs2_journal_access_di(handle, INODE_CACHE(tl_inode), tl_bh,
+                                        OCFS2_JOURNAL_ACCESS_WRITE);
+       if (status < 0) {
+               mlog_errno(status);
+               goto bail;
+       }
+
+       mlog(0, "Log truncate of %u clusters starting at cluster %u to "
+            "%llu (index = %d)\n", num_clusters, start_cluster,
+            (unsigned long long)OCFS2_I(tl_inode)->ip_blkno, index);
+
+       if (ocfs2_truncate_log_can_coalesce(tl, start_cluster)) {
+               /*
+                * Move index back to the record we are coalescing with.
+                * ocfs2_truncate_log_can_coalesce() guarantees nonzero
+                */
+               index--;
+
+               num_clusters += le32_to_cpu(tl->tl_recs[index].t_clusters);
+               mlog(0, "Coalesce with index %u (start = %u, clusters = %u)\n",
+                    index, le32_to_cpu(tl->tl_recs[index].t_start),
+                    num_clusters);
+       } else {
+               tl->tl_recs[index].t_start = cpu_to_le32(start_cluster);
+               tl->tl_used = cpu_to_le16(index + 1);
+       }
+       tl->tl_recs[index].t_clusters = cpu_to_le32(num_clusters);
+
+       status = ocfs2_journal_dirty(handle, tl_bh);
+       if (status < 0) {
+               mlog_errno(status);
+               goto bail;
+       }
+
+bail:
+       mlog_exit(status);
+       return status;
+}
+
+static int ocfs2_replay_truncate_records(struct ocfs2_super *osb,
+                                        handle_t *handle,
+                                        struct inode *data_alloc_inode,
+                                        struct buffer_head *data_alloc_bh)
+{
+       int status = 0;
+       int i;
+       unsigned int num_clusters;
+       u64 start_blk;
+       struct ocfs2_truncate_rec rec;
+       struct ocfs2_dinode *di;
+       struct ocfs2_truncate_log *tl;
+       struct inode *tl_inode = osb->osb_tl_inode;
+       struct buffer_head *tl_bh = osb->osb_tl_bh;
+
+       mlog_entry_void();
+
+       di = (struct ocfs2_dinode *) tl_bh->b_data;
+       tl = &di->id2.i_dealloc;
+       i = le16_to_cpu(tl->tl_used) - 1;
+       while (i >= 0) {
+               /* Caller has given us at least enough credits to
+                * update the truncate log dinode */
+               status = ocfs2_journal_access_di(handle, INODE_CACHE(tl_inode), tl_bh,
+                                                OCFS2_JOURNAL_ACCESS_WRITE);
+               if (status < 0) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+
+               tl->tl_used = cpu_to_le16(i);
+
+               status = ocfs2_journal_dirty(handle, tl_bh);
+               if (status < 0) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+
+               /* TODO: Perhaps we can calculate the bulk of the
+                * credits up front rather than extending like
+                * this. */
+               status = ocfs2_extend_trans(handle,
+                                           OCFS2_TRUNCATE_LOG_FLUSH_ONE_REC);
+               if (status < 0) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+
+               rec = tl->tl_recs[i];
+               start_blk = ocfs2_clusters_to_blocks(data_alloc_inode->i_sb,
+                                                   le32_to_cpu(rec.t_start));
+               num_clusters = le32_to_cpu(rec.t_clusters);
+
+               /* if start_blk is not set, we ignore the record as
+                * invalid. */
+               if (start_blk) {
+                       mlog(0, "free record %d, start = %u, clusters = %u\n",
+                            i, le32_to_cpu(rec.t_start), num_clusters);
+
+                       status = ocfs2_free_clusters(handle, data_alloc_inode,
+                                                    data_alloc_bh, start_blk,
+                                                    num_clusters);
+                       if (status < 0) {
+                               mlog_errno(status);
+                               goto bail;
+                       }
+               }
+               i--;
+       }
+
+bail:
+       mlog_exit(status);
+       return status;
+}
+
+/* Expects you to already be holding tl_inode->i_mutex */
+int __ocfs2_flush_truncate_log(struct ocfs2_super *osb)
+{
+       int status;
+       unsigned int num_to_flush;
+       handle_t *handle;
+       struct inode *tl_inode = osb->osb_tl_inode;
+       struct inode *data_alloc_inode = NULL;
+       struct buffer_head *tl_bh = osb->osb_tl_bh;
+       struct buffer_head *data_alloc_bh = NULL;
+       struct ocfs2_dinode *di;
+       struct ocfs2_truncate_log *tl;
+
+       mlog_entry_void();
+
+       BUG_ON(mutex_trylock(&tl_inode->i_mutex));
+
+       di = (struct ocfs2_dinode *) tl_bh->b_data;
+
+       /* tl_bh is loaded from ocfs2_truncate_log_init().  It's validated
+        * by the underlying call to ocfs2_read_inode_block(), so any
+        * corruption is a code bug */
+       BUG_ON(!OCFS2_IS_VALID_DINODE(di));
+
+       tl = &di->id2.i_dealloc;
+       num_to_flush = le16_to_cpu(tl->tl_used);
+       mlog(0, "Flush %u records from truncate log #%llu\n",
+            num_to_flush, (unsigned long long)OCFS2_I(tl_inode)->ip_blkno);
+       if (!num_to_flush) {
+               status = 0;
+               goto out;
+       }
+
+       data_alloc_inode = ocfs2_get_system_file_inode(osb,
+                                                      GLOBAL_BITMAP_SYSTEM_INODE,
+                                                      OCFS2_INVALID_SLOT);
+       if (!data_alloc_inode) {
+               status = -EINVAL;
+               mlog(ML_ERROR, "Could not get bitmap inode!\n");
+               goto out;
+       }
+
+       mutex_lock(&data_alloc_inode->i_mutex);
+
+       status = ocfs2_inode_lock(data_alloc_inode, &data_alloc_bh, 1);
+       if (status < 0) {
+               mlog_errno(status);
+               goto out_mutex;
+       }
+
+       handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
+       if (IS_ERR(handle)) {
+               status = PTR_ERR(handle);
+               mlog_errno(status);
+               goto out_unlock;
+       }
+
+       status = ocfs2_replay_truncate_records(osb, handle, data_alloc_inode,
+                                              data_alloc_bh);
+       if (status < 0)
+               mlog_errno(status);
+
+       ocfs2_commit_trans(osb, handle);
+
+out_unlock:
+       brelse(data_alloc_bh);
+       ocfs2_inode_unlock(data_alloc_inode, 1);
+
+out_mutex:
+       mutex_unlock(&data_alloc_inode->i_mutex);
+       iput(data_alloc_inode);
+
+out:
+       mlog_exit(status);
+       return status;
+}
+
+int ocfs2_flush_truncate_log(struct ocfs2_super *osb)
+{
+       int status;
+       struct inode *tl_inode = osb->osb_tl_inode;
+
+       mutex_lock(&tl_inode->i_mutex);
+       status = __ocfs2_flush_truncate_log(osb);
+       mutex_unlock(&tl_inode->i_mutex);
+
+       return status;
+}
+
+static void ocfs2_truncate_log_worker(struct work_struct *work)
+{
+       int status;
+       struct ocfs2_super *osb =
+               container_of(work, struct ocfs2_super,
+                            osb_truncate_log_wq.work);
+
+       mlog_entry_void();
+
+       status = ocfs2_flush_truncate_log(osb);
+       if (status < 0)
+               mlog_errno(status);
+       else
+               ocfs2_init_inode_steal_slot(osb);
+
+       mlog_exit(status);
+}
+
+#define OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL (2 * HZ)
+void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
+                                      int cancel)
+{
+       if (osb->osb_tl_inode) {
+               /* We want to push off log flushes while truncates are
+                * still running. */
+               if (cancel)
+                       cancel_delayed_work(&osb->osb_truncate_log_wq);
+
+               queue_delayed_work(ocfs2_wq, &osb->osb_truncate_log_wq,
+                                  OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL);
+       }
+}
+
+static int ocfs2_get_truncate_log_info(struct ocfs2_super *osb,
+                                      int slot_num,
+                                      struct inode **tl_inode,
+                                      struct buffer_head **tl_bh)
+{
+       int status;
+       struct inode *inode = NULL;
+       struct buffer_head *bh = NULL;
+
+       inode = ocfs2_get_system_file_inode(osb,
+                                          TRUNCATE_LOG_SYSTEM_INODE,
+                                          slot_num);
+       if (!inode) {
+               status = -EINVAL;
+               mlog(ML_ERROR, "Could not get load truncate log inode!\n");
+               goto bail;
+       }
+
+       status = ocfs2_read_inode_block(inode, &bh);
+       if (status < 0) {
+               iput(inode);
+               mlog_errno(status);
+               goto bail;
+       }
+
+       *tl_inode = inode;
+       *tl_bh    = bh;
+bail:
+       mlog_exit(status);
+       return status;
+}
+
+/* called during the 1st stage of node recovery. we stamp a clean
+ * truncate log and pass back a copy for processing later. if the
+ * truncate log does not require processing, a *tl_copy is set to
+ * NULL. */
+int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
+                                     int slot_num,
+                                     struct ocfs2_dinode **tl_copy)
+{
        int status;
-       struct ocfs2_super *osb =
-               container_of(work, struct ocfs2_super,
-                            osb_truncate_log_wq.work);
+       struct inode *tl_inode = NULL;
+       struct buffer_head *tl_bh = NULL;
+       struct ocfs2_dinode *di;
+       struct ocfs2_truncate_log *tl;
+
+       *tl_copy = NULL;
+
+       mlog(0, "recover truncate log from slot %d\n", slot_num);
+
+       status = ocfs2_get_truncate_log_info(osb, slot_num, &tl_inode, &tl_bh);
+       if (status < 0) {
+               mlog_errno(status);
+               goto bail;
+       }
+
+       di = (struct ocfs2_dinode *) tl_bh->b_data;
+
+       /* tl_bh is loaded from ocfs2_get_truncate_log_info().  It's
+        * validated by the underlying call to ocfs2_read_inode_block(),
+        * so any corruption is a code bug */
+       BUG_ON(!OCFS2_IS_VALID_DINODE(di));
+
+       tl = &di->id2.i_dealloc;
+       if (le16_to_cpu(tl->tl_used)) {
+               mlog(0, "We'll have %u logs to recover\n",
+                    le16_to_cpu(tl->tl_used));
+
+               *tl_copy = kmalloc(tl_bh->b_size, GFP_KERNEL);
+               if (!(*tl_copy)) {
+                       status = -ENOMEM;
+                       mlog_errno(status);
+                       goto bail;
+               }
+
+               /* Assuming the write-out below goes well, this copy
+                * will be passed back to recovery for processing. */
+               memcpy(*tl_copy, tl_bh->b_data, tl_bh->b_size);
+
+               /* All we need to do to clear the truncate log is set
+                * tl_used. */
+               tl->tl_used = 0;
+
+               ocfs2_compute_meta_ecc(osb->sb, tl_bh->b_data, &di->i_check);
+               status = ocfs2_write_block(osb, tl_bh, INODE_CACHE(tl_inode));
+               if (status < 0) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+       }
+
+bail:
+       if (tl_inode)
+               iput(tl_inode);
+       brelse(tl_bh);
+
+       if (status < 0 && (*tl_copy)) {
+               kfree(*tl_copy);
+               *tl_copy = NULL;
+       }
+
+       mlog_exit(status);
+       return status;
+}
+
+int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
+                                        struct ocfs2_dinode *tl_copy)
+{
+       int status = 0;
+       int i;
+       unsigned int clusters, num_recs, start_cluster;
+       u64 start_blk;
+       handle_t *handle;
+       struct inode *tl_inode = osb->osb_tl_inode;
+       struct ocfs2_truncate_log *tl;
+
+       mlog_entry_void();
+
+       if (OCFS2_I(tl_inode)->ip_blkno == le64_to_cpu(tl_copy->i_blkno)) {
+               mlog(ML_ERROR, "Asked to recover my own truncate log!\n");
+               return -EINVAL;
+       }
+
+       tl = &tl_copy->id2.i_dealloc;
+       num_recs = le16_to_cpu(tl->tl_used);
+       mlog(0, "cleanup %u records from %llu\n", num_recs,
+            (unsigned long long)le64_to_cpu(tl_copy->i_blkno));
+
+       mutex_lock(&tl_inode->i_mutex);
+       for(i = 0; i < num_recs; i++) {
+               if (ocfs2_truncate_log_needs_flush(osb)) {
+                       status = __ocfs2_flush_truncate_log(osb);
+                       if (status < 0) {
+                               mlog_errno(status);
+                               goto bail_up;
+                       }
+               }
+
+               handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
+               if (IS_ERR(handle)) {
+                       status = PTR_ERR(handle);
+                       mlog_errno(status);
+                       goto bail_up;
+               }
+
+               clusters = le32_to_cpu(tl->tl_recs[i].t_clusters);
+               start_cluster = le32_to_cpu(tl->tl_recs[i].t_start);
+               start_blk = ocfs2_clusters_to_blocks(osb->sb, start_cluster);
+
+               status = ocfs2_truncate_log_append(osb, handle,
+                                                  start_blk, clusters);
+               ocfs2_commit_trans(osb, handle);
+               if (status < 0) {
+                       mlog_errno(status);
+                       goto bail_up;
+               }
+       }
+
+bail_up:
+       mutex_unlock(&tl_inode->i_mutex);
+
+       mlog_exit(status);
+       return status;
+}
+
+void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb)
+{
+       int status;
+       struct inode *tl_inode = osb->osb_tl_inode;
+
+       mlog_entry_void();
+
+       if (tl_inode) {
+               cancel_delayed_work(&osb->osb_truncate_log_wq);
+               flush_workqueue(ocfs2_wq);
+
+               status = ocfs2_flush_truncate_log(osb);
+               if (status < 0)
+                       mlog_errno(status);
+
+               brelse(osb->osb_tl_bh);
+               iput(osb->osb_tl_inode);
+       }
+
+       mlog_exit_void();
+}
+
+int ocfs2_truncate_log_init(struct ocfs2_super *osb)
+{
+       int status;
+       struct inode *tl_inode = NULL;
+       struct buffer_head *tl_bh = NULL;
+
+       mlog_entry_void();
+
+       status = ocfs2_get_truncate_log_info(osb,
+                                            osb->slot_num,
+                                            &tl_inode,
+                                            &tl_bh);
+       if (status < 0)
+               mlog_errno(status);
+
+       /* ocfs2_truncate_log_shutdown keys on the existence of
+        * osb->osb_tl_inode so we don't set any of the osb variables
+        * until we're sure all is well. */
+       INIT_DELAYED_WORK(&osb->osb_truncate_log_wq,
+                         ocfs2_truncate_log_worker);
+       osb->osb_tl_bh    = tl_bh;
+       osb->osb_tl_inode = tl_inode;
+
+       mlog_exit(status);
+       return status;
+}
+
+/*
+ * Delayed de-allocation of suballocator blocks.
+ *
+ * Some sets of block de-allocations might involve multiple suballocator inodes.
+ *
+ * The locking for this can get extremely complicated, especially when
+ * the suballocator inodes to delete from aren't known until deep
+ * within an unrelated codepath.
+ *
+ * ocfs2_extent_block structures are a good example of this - an inode
+ * btree could have been grown by any number of nodes each allocating
+ * out of their own suballoc inode.
+ *
+ * These structures allow the delay of block de-allocation until a
+ * later time, when locking of multiple cluster inodes won't cause
+ * deadlock.
+ */
+
+/*
+ * Describe a single bit freed from a suballocator.  For the block
+ * suballocators, it represents one block.  For the global cluster
+ * allocator, it represents some clusters and free_bit indicates
+ * clusters number.
+ */
+struct ocfs2_cached_block_free {
+       struct ocfs2_cached_block_free          *free_next;
+       u64                                     free_blk;
+       unsigned int                            free_bit;
+};
+
+struct ocfs2_per_slot_free_list {
+       struct ocfs2_per_slot_free_list         *f_next_suballocator;
+       int                                     f_inode_type;
+       int                                     f_slot;
+       struct ocfs2_cached_block_free          *f_first;
+};
+
+static int ocfs2_free_cached_blocks(struct ocfs2_super *osb,
+                                   int sysfile_type,
+                                   int slot,
+                                   struct ocfs2_cached_block_free *head)
+{
+       int ret;
+       u64 bg_blkno;
+       handle_t *handle;
+       struct inode *inode;
+       struct buffer_head *di_bh = NULL;
+       struct ocfs2_cached_block_free *tmp;
+
+       inode = ocfs2_get_system_file_inode(osb, sysfile_type, slot);
+       if (!inode) {
+               ret = -EINVAL;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       mutex_lock(&inode->i_mutex);
+
+       ret = ocfs2_inode_lock(inode, &di_bh, 1);
+       if (ret) {
+               mlog_errno(ret);
+               goto out_mutex;
+       }
+
+       handle = ocfs2_start_trans(osb, OCFS2_SUBALLOC_FREE);
+       if (IS_ERR(handle)) {
+               ret = PTR_ERR(handle);
+               mlog_errno(ret);
+               goto out_unlock;
+       }
+
+       while (head) {
+               bg_blkno = ocfs2_which_suballoc_group(head->free_blk,
+                                                     head->free_bit);
+               mlog(0, "Free bit: (bit %u, blkno %llu)\n",
+                    head->free_bit, (unsigned long long)head->free_blk);
+
+               ret = ocfs2_free_suballoc_bits(handle, inode, di_bh,
+                                              head->free_bit, bg_blkno, 1);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out_journal;
+               }
+
+               ret = ocfs2_extend_trans(handle, OCFS2_SUBALLOC_FREE);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out_journal;
+               }
+
+               tmp = head;
+               head = head->free_next;
+               kfree(tmp);
+       }
+
+out_journal:
+       ocfs2_commit_trans(osb, handle);
+
+out_unlock:
+       ocfs2_inode_unlock(inode, 1);
+       brelse(di_bh);
+out_mutex:
+       mutex_unlock(&inode->i_mutex);
+       iput(inode);
+out:
+       while(head) {
+               /* Premature exit may have left some dangling items. */
+               tmp = head;
+               head = head->free_next;
+               kfree(tmp);
+       }
+
+       return ret;
+}
+
+int ocfs2_cache_cluster_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
+                               u64 blkno, unsigned int bit)
+{
+       int ret = 0;
+       struct ocfs2_cached_block_free *item;
+
+       item = kmalloc(sizeof(*item), GFP_NOFS);
+       if (item == NULL) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               return ret;
+       }
+
+       mlog(0, "Insert clusters: (bit %u, blk %llu)\n",
+            bit, (unsigned long long)blkno);
+
+       item->free_blk = blkno;
+       item->free_bit = bit;
+       item->free_next = ctxt->c_global_allocator;
+
+       ctxt->c_global_allocator = item;
+       return ret;
+}
+
+static int ocfs2_free_cached_clusters(struct ocfs2_super *osb,
+                                     struct ocfs2_cached_block_free *head)
+{
+       struct ocfs2_cached_block_free *tmp;
+       struct inode *tl_inode = osb->osb_tl_inode;
+       handle_t *handle;
+       int ret = 0;
+
+       mutex_lock(&tl_inode->i_mutex);
+
+       while (head) {
+               if (ocfs2_truncate_log_needs_flush(osb)) {
+                       ret = __ocfs2_flush_truncate_log(osb);
+                       if (ret < 0) {
+                               mlog_errno(ret);
+                               break;
+                       }
+               }
+
+               handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
+               if (IS_ERR(handle)) {
+                       ret = PTR_ERR(handle);
+                       mlog_errno(ret);
+                       break;
+               }
+
+               ret = ocfs2_truncate_log_append(osb, handle, head->free_blk,
+                                               head->free_bit);
+
+               ocfs2_commit_trans(osb, handle);
+               tmp = head;
+               head = head->free_next;
+               kfree(tmp);
+
+               if (ret < 0) {
+                       mlog_errno(ret);
+                       break;
+               }
+       }
 
-       mlog_entry_void();
+       mutex_unlock(&tl_inode->i_mutex);
 
-       status = ocfs2_flush_truncate_log(osb);
-       if (status < 0)
-               mlog_errno(status);
+       while (head) {
+               /* Premature exit may have left some dangling items. */
+               tmp = head;
+               head = head->free_next;
+               kfree(tmp);
+       }
 
-       mlog_exit(status);
+       return ret;
 }
 
-#define OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL (2 * HZ)
-void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
-                                      int cancel)
+int ocfs2_run_deallocs(struct ocfs2_super *osb,
+                      struct ocfs2_cached_dealloc_ctxt *ctxt)
 {
-       if (osb->osb_tl_inode) {
-               /* We want to push off log flushes while truncates are
-                * still running. */
-               if (cancel)
-                       cancel_delayed_work(&osb->osb_truncate_log_wq);
+       int ret = 0, ret2;
+       struct ocfs2_per_slot_free_list *fl;
 
-               queue_delayed_work(ocfs2_wq, &osb->osb_truncate_log_wq,
-                                  OCFS2_TRUNCATE_LOG_FLUSH_INTERVAL);
+       if (!ctxt)
+               return 0;
+
+       while (ctxt->c_first_suballocator) {
+               fl = ctxt->c_first_suballocator;
+
+               if (fl->f_first) {
+                       mlog(0, "Free items: (type %u, slot %d)\n",
+                            fl->f_inode_type, fl->f_slot);
+                       ret2 = ocfs2_free_cached_blocks(osb,
+                                                       fl->f_inode_type,
+                                                       fl->f_slot,
+                                                       fl->f_first);
+                       if (ret2)
+                               mlog_errno(ret2);
+                       if (!ret)
+                               ret = ret2;
+               }
+
+               ctxt->c_first_suballocator = fl->f_next_suballocator;
+               kfree(fl);
+       }
+
+       if (ctxt->c_global_allocator) {
+               ret2 = ocfs2_free_cached_clusters(osb,
+                                                 ctxt->c_global_allocator);
+               if (ret2)
+                       mlog_errno(ret2);
+               if (!ret)
+                       ret = ret2;
+
+               ctxt->c_global_allocator = NULL;
+       }
+
+       return ret;
+}
+
+static struct ocfs2_per_slot_free_list *
+ocfs2_find_per_slot_free_list(int type,
+                             int slot,
+                             struct ocfs2_cached_dealloc_ctxt *ctxt)
+{
+       struct ocfs2_per_slot_free_list *fl = ctxt->c_first_suballocator;
+
+       while (fl) {
+               if (fl->f_inode_type == type && fl->f_slot == slot)
+                       return fl;
+
+               fl = fl->f_next_suballocator;
+       }
+
+       fl = kmalloc(sizeof(*fl), GFP_NOFS);
+       if (fl) {
+               fl->f_inode_type = type;
+               fl->f_slot = slot;
+               fl->f_first = NULL;
+               fl->f_next_suballocator = ctxt->c_first_suballocator;
+
+               ctxt->c_first_suballocator = fl;
        }
+       return fl;
 }
 
-static int ocfs2_get_truncate_log_info(struct ocfs2_super *osb,
-                                      int slot_num,
-                                      struct inode **tl_inode,
-                                      struct buffer_head **tl_bh)
+int ocfs2_cache_block_dealloc(struct ocfs2_cached_dealloc_ctxt *ctxt,
+                             int type, int slot, u64 blkno,
+                             unsigned int bit)
 {
-       int status;
-       struct inode *inode = NULL;
+       int ret;
+       struct ocfs2_per_slot_free_list *fl;
+       struct ocfs2_cached_block_free *item;
+
+       fl = ocfs2_find_per_slot_free_list(type, slot, ctxt);
+       if (fl == NULL) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       item = kmalloc(sizeof(*item), GFP_NOFS);
+       if (item == NULL) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
+               goto out;
+       }
+
+       mlog(0, "Insert: (type %d, slot %u, bit %u, blk %llu)\n",
+            type, slot, bit, (unsigned long long)blkno);
+
+       item->free_blk = blkno;
+       item->free_bit = bit;
+       item->free_next = fl->f_first;
+
+       fl->f_first = item;
+
+       ret = 0;
+out:
+       return ret;
+}
+
+static int ocfs2_cache_extent_block_free(struct ocfs2_cached_dealloc_ctxt *ctxt,
+                                        struct ocfs2_extent_block *eb)
+{
+       return ocfs2_cache_block_dealloc(ctxt, EXTENT_ALLOC_SYSTEM_INODE,
+                                        le16_to_cpu(eb->h_suballoc_slot),
+                                        le64_to_cpu(eb->h_blkno),
+                                        le16_to_cpu(eb->h_suballoc_bit));
+}
+
+/* This function will figure out whether the currently last extent
+ * block will be deleted, and if it will, what the new last extent
+ * block will be so we can update his h_next_leaf_blk field, as well
+ * as the dinodes i_last_eb_blk */
+static int ocfs2_find_new_last_ext_blk(struct inode *inode,
+                                      unsigned int clusters_to_del,
+                                      struct ocfs2_path *path,
+                                      struct buffer_head **new_last_eb)
+{
+       int next_free, ret = 0;
+       u32 cpos;
+       struct ocfs2_extent_rec *rec;
+       struct ocfs2_extent_block *eb;
+       struct ocfs2_extent_list *el;
        struct buffer_head *bh = NULL;
 
-       inode = ocfs2_get_system_file_inode(osb,
-                                          TRUNCATE_LOG_SYSTEM_INODE,
-                                          slot_num);
-       if (!inode) {
-               status = -EINVAL;
-               mlog(ML_ERROR, "Could not get load truncate log inode!\n");
-               goto bail;
+       *new_last_eb = NULL;
+
+       /* we have no tree, so of course, no last_eb. */
+       if (!path->p_tree_depth)
+               goto out;
+
+       /* trunc to zero special case - this makes tree_depth = 0
+        * regardless of what it is.  */
+       if (OCFS2_I(inode)->ip_clusters == clusters_to_del)
+               goto out;
+
+       el = path_leaf_el(path);
+       BUG_ON(!el->l_next_free_rec);
+
+       /*
+        * Make sure that this extent list will actually be empty
+        * after we clear away the data. We can shortcut out if
+        * there's more than one non-empty extent in the
+        * list. Otherwise, a check of the remaining extent is
+        * necessary.
+        */
+       next_free = le16_to_cpu(el->l_next_free_rec);
+       rec = NULL;
+       if (ocfs2_is_empty_extent(&el->l_recs[0])) {
+               if (next_free > 2)
+                       goto out;
+
+               /* We may have a valid extent in index 1, check it. */
+               if (next_free == 2)
+                       rec = &el->l_recs[1];
+
+               /*
+                * Fall through - no more nonempty extents, so we want
+                * to delete this leaf.
+                */
+       } else {
+               if (next_free > 1)
+                       goto out;
+
+               rec = &el->l_recs[0];
        }
 
-       status = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno, &bh,
-                                 OCFS2_BH_CACHED, inode);
-       if (status < 0) {
-               iput(inode);
-               mlog_errno(status);
-               goto bail;
+       if (rec) {
+               /*
+                * Check it we'll only be trimming off the end of this
+                * cluster.
+                */
+               if (le16_to_cpu(rec->e_leaf_clusters) > clusters_to_del)
+                       goto out;
        }
 
-       *tl_inode = inode;
-       *tl_bh    = bh;
-bail:
-       mlog_exit(status);
-       return status;
+       ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, path, &cpos);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ret = ocfs2_find_leaf(INODE_CACHE(inode), path_root_el(path), cpos, &bh);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       eb = (struct ocfs2_extent_block *) bh->b_data;
+       el = &eb->h_list;
+
+       /* ocfs2_find_leaf() gets the eb from ocfs2_read_extent_block().
+        * Any corruption is a code bug. */
+       BUG_ON(!OCFS2_IS_VALID_EXTENT_BLOCK(eb));
+
+       *new_last_eb = bh;
+       get_bh(*new_last_eb);
+       mlog(0, "returning block %llu, (cpos: %u)\n",
+            (unsigned long long)le64_to_cpu(eb->h_blkno), cpos);
+out:
+       brelse(bh);
+
+       return ret;
 }
 
-/* called during the 1st stage of node recovery. we stamp a clean
- * truncate log and pass back a copy for processing later. if the
- * truncate log does not require processing, a *tl_copy is set to
- * NULL. */
-int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb,
-                                     int slot_num,
-                                     struct ocfs2_dinode **tl_copy)
+/*
+ * Trim some clusters off the rightmost edge of a tree. Only called
+ * during truncate.
+ *
+ * The caller needs to:
+ *   - start journaling of each path component.
+ *   - compute and fully set up any new last ext block
+ */
+static int ocfs2_trim_tree(struct inode *inode, struct ocfs2_path *path,
+                          handle_t *handle, struct ocfs2_truncate_context *tc,
+                          u32 clusters_to_del, u64 *delete_start, u8 *flags)
 {
-       int status;
-       struct inode *tl_inode = NULL;
-       struct buffer_head *tl_bh = NULL;
-       struct ocfs2_dinode *di;
-       struct ocfs2_truncate_log *tl;
+       int ret, i, index = path->p_tree_depth;
+       u32 new_edge = 0;
+       u64 deleted_eb = 0;
+       struct buffer_head *bh;
+       struct ocfs2_extent_list *el;
+       struct ocfs2_extent_rec *rec;
 
-       *tl_copy = NULL;
+       *delete_start = 0;
+       *flags = 0;
+
+       while (index >= 0) {
+               bh = path->p_node[index].bh;
+               el = path->p_node[index].el;
+
+               mlog(0, "traveling tree (index = %d, block = %llu)\n",
+                    index,  (unsigned long long)bh->b_blocknr);
+
+               BUG_ON(le16_to_cpu(el->l_next_free_rec) == 0);
+
+               if (index !=
+                   (path->p_tree_depth - le16_to_cpu(el->l_tree_depth))) {
+                       ocfs2_error(inode->i_sb,
+                                   "Inode %lu has invalid ext. block %llu",
+                                   inode->i_ino,
+                                   (unsigned long long)bh->b_blocknr);
+                       ret = -EROFS;
+                       goto out;
+               }
+
+find_tail_record:
+               i = le16_to_cpu(el->l_next_free_rec) - 1;
+               rec = &el->l_recs[i];
+
+               mlog(0, "Extent list before: record %d: (%u, %u, %llu), "
+                    "next = %u\n", i, le32_to_cpu(rec->e_cpos),
+                    ocfs2_rec_clusters(el, rec),
+                    (unsigned long long)le64_to_cpu(rec->e_blkno),
+                    le16_to_cpu(el->l_next_free_rec));
+
+               BUG_ON(ocfs2_rec_clusters(el, rec) < clusters_to_del);
+
+               if (le16_to_cpu(el->l_tree_depth) == 0) {
+                       /*
+                        * If the leaf block contains a single empty
+                        * extent and no records, we can just remove
+                        * the block.
+                        */
+                       if (i == 0 && ocfs2_is_empty_extent(rec)) {
+                               memset(rec, 0,
+                                      sizeof(struct ocfs2_extent_rec));
+                               el->l_next_free_rec = cpu_to_le16(0);
+
+                               goto delete;
+                       }
+
+                       /*
+                        * Remove any empty extents by shifting things
+                        * left. That should make life much easier on
+                        * the code below. This condition is rare
+                        * enough that we shouldn't see a performance
+                        * hit.
+                        */
+                       if (ocfs2_is_empty_extent(&el->l_recs[0])) {
+                               le16_add_cpu(&el->l_next_free_rec, -1);
+
+                               for(i = 0;
+                                   i < le16_to_cpu(el->l_next_free_rec); i++)
+                                       el->l_recs[i] = el->l_recs[i + 1];
+
+                               memset(&el->l_recs[i], 0,
+                                      sizeof(struct ocfs2_extent_rec));
+
+                               /*
+                                * We've modified our extent list. The
+                                * simplest way to handle this change
+                                * is to being the search from the
+                                * start again.
+                                */
+                               goto find_tail_record;
+                       }
+
+                       le16_add_cpu(&rec->e_leaf_clusters, -clusters_to_del);
+
+                       /*
+                        * We'll use "new_edge" on our way back up the
+                        * tree to know what our rightmost cpos is.
+                        */
+                       new_edge = le16_to_cpu(rec->e_leaf_clusters);
+                       new_edge += le32_to_cpu(rec->e_cpos);
+
+                       /*
+                        * The caller will use this to delete data blocks.
+                        */
+                       *delete_start = le64_to_cpu(rec->e_blkno)
+                               + ocfs2_clusters_to_blocks(inode->i_sb,
+                                       le16_to_cpu(rec->e_leaf_clusters));
+                       *flags = rec->e_flags;
+
+                       /*
+                        * If it's now empty, remove this record.
+                        */
+                       if (le16_to_cpu(rec->e_leaf_clusters) == 0) {
+                               memset(rec, 0,
+                                      sizeof(struct ocfs2_extent_rec));
+                               le16_add_cpu(&el->l_next_free_rec, -1);
+                       }
+               } else {
+                       if (le64_to_cpu(rec->e_blkno) == deleted_eb) {
+                               memset(rec, 0,
+                                      sizeof(struct ocfs2_extent_rec));
+                               le16_add_cpu(&el->l_next_free_rec, -1);
+
+                               goto delete;
+                       }
+
+                       /* Can this actually happen? */
+                       if (le16_to_cpu(el->l_next_free_rec) == 0)
+                               goto delete;
+
+                       /*
+                        * We never actually deleted any clusters
+                        * because our leaf was empty. There's no
+                        * reason to adjust the rightmost edge then.
+                        */
+                       if (new_edge == 0)
+                               goto delete;
+
+                       rec->e_int_clusters = cpu_to_le32(new_edge);
+                       le32_add_cpu(&rec->e_int_clusters,
+                                    -le32_to_cpu(rec->e_cpos));
+
+                        /*
+                         * A deleted child record should have been
+                         * caught above.
+                         */
+                        BUG_ON(le32_to_cpu(rec->e_int_clusters) == 0);
+               }
+
+delete:
+               ret = ocfs2_journal_dirty(handle, bh);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               mlog(0, "extent list container %llu, after: record %d: "
+                    "(%u, %u, %llu), next = %u.\n",
+                    (unsigned long long)bh->b_blocknr, i,
+                    le32_to_cpu(rec->e_cpos), ocfs2_rec_clusters(el, rec),
+                    (unsigned long long)le64_to_cpu(rec->e_blkno),
+                    le16_to_cpu(el->l_next_free_rec));
+
+               /*
+                * We must be careful to only attempt delete of an
+                * extent block (and not the root inode block).
+                */
+               if (index > 0 && le16_to_cpu(el->l_next_free_rec) == 0) {
+                       struct ocfs2_extent_block *eb =
+                               (struct ocfs2_extent_block *)bh->b_data;
+
+                       /*
+                        * Save this for use when processing the
+                        * parent block.
+                        */
+                       deleted_eb = le64_to_cpu(eb->h_blkno);
+
+                       mlog(0, "deleting this extent block.\n");
+
+                       ocfs2_remove_from_cache(INODE_CACHE(inode), bh);
+
+                       BUG_ON(ocfs2_rec_clusters(el, &el->l_recs[0]));
+                       BUG_ON(le32_to_cpu(el->l_recs[0].e_cpos));
+                       BUG_ON(le64_to_cpu(el->l_recs[0].e_blkno));
+
+                       ret = ocfs2_cache_extent_block_free(&tc->tc_dealloc, eb);
+                       /* An error here is not fatal. */
+                       if (ret < 0)
+                               mlog_errno(ret);
+               } else {
+                       deleted_eb = 0;
+               }
+
+               index--;
+       }
+
+       ret = 0;
+out:
+       return ret;
+}
+
+static int ocfs2_do_truncate(struct ocfs2_super *osb,
+                            unsigned int clusters_to_del,
+                            struct inode *inode,
+                            struct buffer_head *fe_bh,
+                            handle_t *handle,
+                            struct ocfs2_truncate_context *tc,
+                            struct ocfs2_path *path,
+                            struct ocfs2_alloc_context *meta_ac)
+{
+       int status;
+       struct ocfs2_dinode *fe;
+       struct ocfs2_extent_block *last_eb = NULL;
+       struct ocfs2_extent_list *el;
+       struct buffer_head *last_eb_bh = NULL;
+       u64 delete_blk = 0;
+       u8 rec_flags;
 
-       mlog(0, "recover truncate log from slot %d\n", slot_num);
+       fe = (struct ocfs2_dinode *) fe_bh->b_data;
 
-       status = ocfs2_get_truncate_log_info(osb, slot_num, &tl_inode, &tl_bh);
+       status = ocfs2_find_new_last_ext_blk(inode, clusters_to_del,
+                                            path, &last_eb_bh);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
 
-       di = (struct ocfs2_dinode *) tl_bh->b_data;
-       tl = &di->id2.i_dealloc;
-       if (!OCFS2_IS_VALID_DINODE(di)) {
-               OCFS2_RO_ON_INVALID_DINODE(tl_inode->i_sb, di);
-               status = -EIO;
+       /*
+        * Each component will be touched, so we might as well journal
+        * here to avoid having to handle errors later.
+        */
+       status = ocfs2_journal_access_path(INODE_CACHE(inode), handle, path);
+       if (status < 0) {
+               mlog_errno(status);
                goto bail;
        }
 
-       if (le16_to_cpu(tl->tl_used)) {
-               mlog(0, "We'll have %u logs to recover\n",
-                    le16_to_cpu(tl->tl_used));
-
-               *tl_copy = kmalloc(tl_bh->b_size, GFP_KERNEL);
-               if (!(*tl_copy)) {
-                       status = -ENOMEM;
+       if (last_eb_bh) {
+               status = ocfs2_journal_access_eb(handle, INODE_CACHE(inode), last_eb_bh,
+                                                OCFS2_JOURNAL_ACCESS_WRITE);
+               if (status < 0) {
                        mlog_errno(status);
                        goto bail;
                }
 
-               /* Assuming the write-out below goes well, this copy
-                * will be passed back to recovery for processing. */
-               memcpy(*tl_copy, tl_bh->b_data, tl_bh->b_size);
+               last_eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+       }
 
-               /* All we need to do to clear the truncate log is set
-                * tl_used. */
-               tl->tl_used = 0;
+       el = &(fe->id2.i_list);
+
+       /*
+        * Lower levels depend on this never happening, but it's best
+        * to check it up here before changing the tree.
+        */
+       if (el->l_tree_depth && el->l_recs[0].e_int_clusters == 0) {
+               ocfs2_error(inode->i_sb,
+                           "Inode %lu has an empty extent record, depth %u\n",
+                           inode->i_ino, le16_to_cpu(el->l_tree_depth));
+               status = -EROFS;
+               goto bail;
+       }
+
+       vfs_dq_free_space_nodirty(inode,
+                       ocfs2_clusters_to_bytes(osb->sb, clusters_to_del));
+       spin_lock(&OCFS2_I(inode)->ip_lock);
+       OCFS2_I(inode)->ip_clusters = le32_to_cpu(fe->i_clusters) -
+                                     clusters_to_del;
+       spin_unlock(&OCFS2_I(inode)->ip_lock);
+       le32_add_cpu(&fe->i_clusters, -clusters_to_del);
+       inode->i_blocks = ocfs2_inode_sector_count(inode);
+
+       status = ocfs2_trim_tree(inode, path, handle, tc,
+                                clusters_to_del, &delete_blk, &rec_flags);
+       if (status) {
+               mlog_errno(status);
+               goto bail;
+       }
+
+       if (le32_to_cpu(fe->i_clusters) == 0) {
+               /* trunc to zero is a special case. */
+               el->l_tree_depth = 0;
+               fe->i_last_eb_blk = 0;
+       } else if (last_eb)
+               fe->i_last_eb_blk = last_eb->h_blkno;
 
-               status = ocfs2_write_block(osb, tl_bh, tl_inode);
+       status = ocfs2_journal_dirty(handle, fe_bh);
+       if (status < 0) {
+               mlog_errno(status);
+               goto bail;
+       }
+
+       if (last_eb) {
+               /* If there will be a new last extent block, then by
+                * definition, there cannot be any leaves to the right of
+                * him. */
+               last_eb->h_next_leaf_blk = 0;
+               status = ocfs2_journal_dirty(handle, last_eb_bh);
                if (status < 0) {
                        mlog_errno(status);
                        goto bail;
                }
        }
 
-bail:
-       if (tl_inode)
-               iput(tl_inode);
-       if (tl_bh)
-               brelse(tl_bh);
-
-       if (status < 0 && (*tl_copy)) {
-               kfree(*tl_copy);
-               *tl_copy = NULL;
+       if (delete_blk) {
+               if (rec_flags & OCFS2_EXT_REFCOUNTED)
+                       status = ocfs2_decrease_refcount(inode, handle,
+                                       ocfs2_blocks_to_clusters(osb->sb,
+                                                                delete_blk),
+                                       clusters_to_del, meta_ac,
+                                       &tc->tc_dealloc, 1);
+               else
+                       status = ocfs2_truncate_log_append(osb, handle,
+                                                          delete_blk,
+                                                          clusters_to_del);
+               if (status < 0) {
+                       mlog_errno(status);
+                       goto bail;
+               }
        }
-
+       status = 0;
+bail:
+       brelse(last_eb_bh);
        mlog_exit(status);
        return status;
 }
 
-int ocfs2_complete_truncate_log_recovery(struct ocfs2_super *osb,
-                                        struct ocfs2_dinode *tl_copy)
+static int ocfs2_zero_func(handle_t *handle, struct buffer_head *bh)
 {
-       int status = 0;
-       int i;
-       unsigned int clusters, num_recs, start_cluster;
-       u64 start_blk;
-       handle_t *handle;
-       struct inode *tl_inode = osb->osb_tl_inode;
-       struct ocfs2_truncate_log *tl;
+       set_buffer_uptodate(bh);
+       mark_buffer_dirty(bh);
+       return 0;
+}
 
-       mlog_entry_void();
+void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle,
+                             unsigned int from, unsigned int to,
+                             struct page *page, int zero, u64 *phys)
+{
+       int ret, partial = 0;
 
-       if (OCFS2_I(tl_inode)->ip_blkno == le64_to_cpu(tl_copy->i_blkno)) {
-               mlog(ML_ERROR, "Asked to recover my own truncate log!\n");
-               return -EINVAL;
+       ret = ocfs2_map_page_blocks(page, phys, inode, from, to, 0);
+       if (ret)
+               mlog_errno(ret);
+
+       if (zero)
+               zero_user_segment(page, from, to);
+
+       /*
+        * Need to set the buffers we zero'd into uptodate
+        * here if they aren't - ocfs2_map_page_blocks()
+        * might've skipped some
+        */
+       ret = walk_page_buffers(handle, page_buffers(page),
+                               from, to, &partial,
+                               ocfs2_zero_func);
+       if (ret < 0)
+               mlog_errno(ret);
+       else if (ocfs2_should_order_data(inode)) {
+               ret = ocfs2_jbd2_file_inode(handle, inode);
+               if (ret < 0)
+                       mlog_errno(ret);
        }
 
-       tl = &tl_copy->id2.i_dealloc;
-       num_recs = le16_to_cpu(tl->tl_used);
-       mlog(0, "cleanup %u records from %llu\n", num_recs,
-            (unsigned long long)tl_copy->i_blkno);
+       if (!partial)
+               SetPageUptodate(page);
 
-       mutex_lock(&tl_inode->i_mutex);
-       for(i = 0; i < num_recs; i++) {
-               if (ocfs2_truncate_log_needs_flush(osb)) {
-                       status = __ocfs2_flush_truncate_log(osb);
-                       if (status < 0) {
-                               mlog_errno(status);
-                               goto bail_up;
-                       }
-               }
+       flush_dcache_page(page);
+}
 
-               handle = ocfs2_start_trans(osb, OCFS2_TRUNCATE_LOG_UPDATE);
-               if (IS_ERR(handle)) {
-                       status = PTR_ERR(handle);
-                       mlog_errno(status);
-                       goto bail_up;
-               }
+static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t start,
+                                    loff_t end, struct page **pages,
+                                    int numpages, u64 phys, handle_t *handle)
+{
+       int i;
+       struct page *page;
+       unsigned int from, to = PAGE_CACHE_SIZE;
+       struct super_block *sb = inode->i_sb;
 
-               clusters = le32_to_cpu(tl->tl_recs[i].t_clusters);
-               start_cluster = le32_to_cpu(tl->tl_recs[i].t_start);
-               start_blk = ocfs2_clusters_to_blocks(osb->sb, start_cluster);
+       BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb)));
 
-               status = ocfs2_truncate_log_append(osb, handle,
-                                                  start_blk, clusters);
-               ocfs2_commit_trans(osb, handle);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail_up;
-               }
-       }
+       if (numpages == 0)
+               goto out;
 
-bail_up:
-       mutex_unlock(&tl_inode->i_mutex);
+       to = PAGE_CACHE_SIZE;
+       for(i = 0; i < numpages; i++) {
+               page = pages[i];
 
-       mlog_exit(status);
-       return status;
+               from = start & (PAGE_CACHE_SIZE - 1);
+               if ((end >> PAGE_CACHE_SHIFT) == page->index)
+                       to = end & (PAGE_CACHE_SIZE - 1);
+
+               BUG_ON(from > PAGE_CACHE_SIZE);
+               BUG_ON(to > PAGE_CACHE_SIZE);
+
+               ocfs2_map_and_dirty_page(inode, handle, from, to, page, 1,
+                                        &phys);
+
+               start = (page->index + 1) << PAGE_CACHE_SHIFT;
+       }
+out:
+       if (pages)
+               ocfs2_unlock_and_free_pages(pages, numpages);
 }
 
-void ocfs2_truncate_log_shutdown(struct ocfs2_super *osb)
+int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end,
+                    struct page **pages, int *num)
 {
-       int status;
-       struct inode *tl_inode = osb->osb_tl_inode;
+       int numpages, ret = 0;
+       struct address_space *mapping = inode->i_mapping;
+       unsigned long index;
+       loff_t last_page_bytes;
 
-       mlog_entry_void();
+       BUG_ON(start > end);
 
-       if (tl_inode) {
-               cancel_delayed_work(&osb->osb_truncate_log_wq);
-               flush_workqueue(ocfs2_wq);
+       numpages = 0;
+       last_page_bytes = PAGE_ALIGN(end);
+       index = start >> PAGE_CACHE_SHIFT;
+       do {
+               pages[numpages] = grab_cache_page(mapping, index);
+               if (!pages[numpages]) {
+                       ret = -ENOMEM;
+                       mlog_errno(ret);
+                       goto out;
+               }
 
-               status = ocfs2_flush_truncate_log(osb);
-               if (status < 0)
-                       mlog_errno(status);
+               numpages++;
+               index++;
+       } while (index < (last_page_bytes >> PAGE_CACHE_SHIFT));
 
-               brelse(osb->osb_tl_bh);
-               iput(osb->osb_tl_inode);
+out:
+       if (ret != 0) {
+               if (pages)
+                       ocfs2_unlock_and_free_pages(pages, numpages);
+               numpages = 0;
        }
 
-       mlog_exit_void();
+       *num = numpages;
+
+       return ret;
 }
 
-int ocfs2_truncate_log_init(struct ocfs2_super *osb)
+static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end,
+                               struct page **pages, int *num)
 {
-       int status;
-       struct inode *tl_inode = NULL;
-       struct buffer_head *tl_bh = NULL;
-
-       mlog_entry_void();
-
-       status = ocfs2_get_truncate_log_info(osb,
-                                            osb->slot_num,
-                                            &tl_inode,
-                                            &tl_bh);
-       if (status < 0)
-               mlog_errno(status);
+       struct super_block *sb = inode->i_sb;
 
-       /* ocfs2_truncate_log_shutdown keys on the existence of
-        * osb->osb_tl_inode so we don't set any of the osb variables
-        * until we're sure all is well. */
-       INIT_DELAYED_WORK(&osb->osb_truncate_log_wq,
-                         ocfs2_truncate_log_worker);
-       osb->osb_tl_bh    = tl_bh;
-       osb->osb_tl_inode = tl_inode;
+       BUG_ON(start >> OCFS2_SB(sb)->s_clustersize_bits !=
+              (end - 1) >> OCFS2_SB(sb)->s_clustersize_bits);
 
-       mlog_exit(status);
-       return status;
+       return ocfs2_grab_pages(inode, start, end, pages, num);
 }
 
-/* This function will figure out whether the currently last extent
- * block will be deleted, and if it will, what the new last extent
- * block will be so we can update his h_next_leaf_blk field, as well
- * as the dinodes i_last_eb_blk */
-static int ocfs2_find_new_last_ext_blk(struct inode *inode,
-                                      u32 new_i_clusters,
-                                      struct ocfs2_path *path,
-                                      struct buffer_head **new_last_eb)
+/*
+ * Zero the area past i_size but still within an allocated
+ * cluster. This avoids exposing nonzero data on subsequent file
+ * extends.
+ *
+ * We need to call this before i_size is updated on the inode because
+ * otherwise block_write_full_page() will skip writeout of pages past
+ * i_size. The new_i_size parameter is passed for this reason.
+ */
+int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
+                                 u64 range_start, u64 range_end)
 {
-       int ret = 0;
-       u32 cpos;
-       struct ocfs2_extent_block *eb;
-       struct ocfs2_extent_list *el;
-       struct buffer_head *bh = NULL;
-
-       *new_last_eb = NULL;
+       int ret = 0, numpages;
+       struct page **pages = NULL;
+       u64 phys;
+       unsigned int ext_flags;
+       struct super_block *sb = inode->i_sb;
 
-       /* we have no tree, so of course, no last_eb. */
-       if (!path->p_tree_depth)
-               goto out;
+       /*
+        * File systems which don't support sparse files zero on every
+        * extend.
+        */
+       if (!ocfs2_sparse_alloc(OCFS2_SB(sb)))
+               return 0;
 
-       /* trunc to zero special case - this makes tree_depth = 0
-        * regardless of what it is.  */
-       if (!new_i_clusters)
+       pages = kcalloc(ocfs2_pages_per_cluster(sb),
+                       sizeof(struct page *), GFP_NOFS);
+       if (pages == NULL) {
+               ret = -ENOMEM;
+               mlog_errno(ret);
                goto out;
+       }
 
-       el = path_leaf_el(path);
-       BUG_ON(!el->l_next_free_rec);
-
-       /* Make sure that this guy will actually be empty after we
-        * clear away the data. */
-       if (ocfs2_is_empty_extent(&el->l_recs[0])) {
-               if (le16_to_cpu(el->l_next_free_rec) > 1 &&
-                   le32_to_cpu(el->l_recs[1].e_cpos) < new_i_clusters)
-                       goto out;
-       } else if (le32_to_cpu(el->l_recs[0].e_cpos) < new_i_clusters)
+       if (range_start == range_end)
                goto out;
 
-       ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, path, &cpos);
+       ret = ocfs2_extent_map_get_blocks(inode,
+                                         range_start >> sb->s_blocksize_bits,
+                                         &phys, NULL, &ext_flags);
        if (ret) {
                mlog_errno(ret);
                goto out;
        }
 
-       ret = ocfs2_find_leaf(inode, path_root_el(path), cpos, &bh);
+       /*
+        * Tail is a hole, or is marked unwritten. In either case, we
+        * can count on read and write to return/push zero's.
+        */
+       if (phys == 0 || ext_flags & OCFS2_EXT_UNWRITTEN)
+               goto out;
+
+       ret = ocfs2_grab_eof_pages(inode, range_start, range_end, pages,
+                                  &numpages);
        if (ret) {
                mlog_errno(ret);
                goto out;
        }
 
-       eb = (struct ocfs2_extent_block *) bh->b_data;
-       el = &eb->h_list;
-       if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
-               OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
-               ret = -EROFS;
-               goto out;
-       }
+       ocfs2_zero_cluster_pages(inode, range_start, range_end, pages,
+                                numpages, phys, handle);
+
+       /*
+        * Initiate writeout of the pages we zero'd here. We don't
+        * wait on them - the truncate_inode_pages() call later will
+        * do that for us.
+        */
+       ret = do_sync_mapping_range(inode->i_mapping, range_start,
+                                   range_end - 1, SYNC_FILE_RANGE_WRITE);
+       if (ret)
+               mlog_errno(ret);
 
-       *new_last_eb = bh;
-       get_bh(*new_last_eb);
-       mlog(0, "returning block %llu, (cpos: %u)\n",
-            (unsigned long long)le64_to_cpu(eb->h_blkno), cpos);
 out:
-       brelse(bh);
+       if (pages)
+               kfree(pages);
+
+       return ret;
+}
 
-       return ret;
+static void ocfs2_zero_dinode_id2_with_xattr(struct inode *inode,
+                                            struct ocfs2_dinode *di)
+{
+       unsigned int blocksize = 1 << inode->i_sb->s_blocksize_bits;
+       unsigned int xattrsize = le16_to_cpu(di->i_xattr_inline_size);
+
+       if (le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_XATTR_FL)
+               memset(&di->id2, 0, blocksize -
+                                   offsetof(struct ocfs2_dinode, id2) -
+                                   xattrsize);
+       else
+               memset(&di->id2, 0, blocksize -
+                                   offsetof(struct ocfs2_dinode, id2));
 }
 
-static int ocfs2_do_truncate(struct ocfs2_super *osb,
-                            unsigned int clusters_to_del,
-                            struct inode *inode,
-                            struct buffer_head *fe_bh,
-                            handle_t *handle,
-                            struct ocfs2_truncate_context *tc,
-                            struct ocfs2_path *path)
+void ocfs2_dinode_new_extent_list(struct inode *inode,
+                                 struct ocfs2_dinode *di)
 {
-       int status, i, index;
-       struct ocfs2_dinode *fe;
-       struct ocfs2_extent_block *eb;
-       struct ocfs2_extent_block *last_eb = NULL;
-       struct ocfs2_extent_list *el;
-       struct buffer_head *eb_bh = NULL;
-       struct buffer_head *last_eb_bh = NULL;
-       u64 delete_blk = 0;
+       ocfs2_zero_dinode_id2_with_xattr(inode, di);
+       di->id2.i_list.l_tree_depth = 0;
+       di->id2.i_list.l_next_free_rec = 0;
+       di->id2.i_list.l_count = cpu_to_le16(
+               ocfs2_extent_recs_per_inode_with_xattr(inode->i_sb, di));
+}
 
-       fe = (struct ocfs2_dinode *) fe_bh->b_data;
+void ocfs2_set_inode_data_inline(struct inode *inode, struct ocfs2_dinode *di)
+{
+       struct ocfs2_inode_info *oi = OCFS2_I(inode);
+       struct ocfs2_inline_data *idata = &di->id2.i_data;
 
-       status = ocfs2_find_new_last_ext_blk(inode,
-                                            le32_to_cpu(fe->i_clusters) -
-                                            clusters_to_del,
-                                            path, &last_eb_bh);
-       if (status < 0) {
-               mlog_errno(status);
-               goto bail;
-       }
+       spin_lock(&oi->ip_lock);
+       oi->ip_dyn_features |= OCFS2_INLINE_DATA_FL;
+       di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
+       spin_unlock(&oi->ip_lock);
 
        /*
-        * Each component will be touched, so we might as well journal
-        * here to avoid having to handle errors later.
+        * We clear the entire i_data structure here so that all
+        * fields can be properly initialized.
         */
-       for (i = 0; i < path_num_items(path); i++) {
-               status = ocfs2_journal_access(handle, inode,
-                                             path->p_node[i].bh,
-                                             OCFS2_JOURNAL_ACCESS_WRITE);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
-               }
-       }
+       ocfs2_zero_dinode_id2_with_xattr(inode, di);
 
-       if (last_eb_bh) {
-               status = ocfs2_journal_access(handle, inode, last_eb_bh,
-                                             OCFS2_JOURNAL_ACCESS_WRITE);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
+       idata->id_count = cpu_to_le16(
+                       ocfs2_max_inline_data_with_xattr(inode->i_sb, di));
+}
+
+int ocfs2_convert_inline_data_to_extents(struct inode *inode,
+                                        struct buffer_head *di_bh)
+{
+       int ret, i, has_data, num_pages = 0;
+       handle_t *handle;
+       u64 uninitialized_var(block);
+       struct ocfs2_inode_info *oi = OCFS2_I(inode);
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+       struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
+       struct ocfs2_alloc_context *data_ac = NULL;
+       struct page **pages = NULL;
+       loff_t end = osb->s_clustersize;
+       struct ocfs2_extent_tree et;
+       int did_quota = 0;
+
+       has_data = i_size_read(inode) ? 1 : 0;
+
+       if (has_data) {
+               pages = kcalloc(ocfs2_pages_per_cluster(osb->sb),
+                               sizeof(struct page *), GFP_NOFS);
+               if (pages == NULL) {
+                       ret = -ENOMEM;
+                       mlog_errno(ret);
+                       goto out;
                }
 
-               last_eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
+               ret = ocfs2_reserve_clusters(osb, 1, &data_ac);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
        }
 
-       el = &(fe->id2.i_list);
-
-       /*
-        * Lower levels depend on this never happening, but it's best
-        * to check it up here before changing the tree.
-        */
-       if (el->l_tree_depth && ocfs2_is_empty_extent(&el->l_recs[0])) {
-               ocfs2_error(inode->i_sb,
-                           "Inode %lu has an empty extent record, depth %u\n",
-                           inode->i_ino, le16_to_cpu(el->l_tree_depth));
-               goto bail;
+       handle = ocfs2_start_trans(osb,
+                                  ocfs2_inline_to_extents_credits(osb->sb));
+       if (IS_ERR(handle)) {
+               ret = PTR_ERR(handle);
+               mlog_errno(ret);
+               goto out_unlock;
        }
 
-       spin_lock(&OCFS2_I(inode)->ip_lock);
-       OCFS2_I(inode)->ip_clusters = le32_to_cpu(fe->i_clusters) -
-                                     clusters_to_del;
-       spin_unlock(&OCFS2_I(inode)->ip_lock);
-       le32_add_cpu(&fe->i_clusters, -clusters_to_del);
+       ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
+                                     OCFS2_JOURNAL_ACCESS_WRITE);
+       if (ret) {
+               mlog_errno(ret);
+               goto out_commit;
+       }
 
-       i = le16_to_cpu(el->l_next_free_rec) - 1;
+       if (has_data) {
+               u32 bit_off, num;
+               unsigned int page_end;
+               u64 phys;
 
-       BUG_ON(le32_to_cpu(el->l_recs[i].e_clusters) < clusters_to_del);
-       le32_add_cpu(&el->l_recs[i].e_clusters, -clusters_to_del);
-       /* tree depth zero, we can just delete the clusters, otherwise
-        * we need to record the offset of the next level extent block
-        * as we may overwrite it. */
-       if (!el->l_tree_depth) {
-               delete_blk = le64_to_cpu(el->l_recs[i].e_blkno)
-                       + ocfs2_clusters_to_blocks(osb->sb,
-                                       le32_to_cpu(el->l_recs[i].e_clusters));
-
-               if (!el->l_recs[i].e_clusters) {
-                       /* if we deleted the whole extent record, then clear
-                        * out the other fields and update the extent
-                        * list.
-                        */
-                       el->l_recs[i].e_cpos = 0;
-                       el->l_recs[i].e_blkno = 0;
-                       BUG_ON(!el->l_next_free_rec);
-                       le16_add_cpu(&el->l_next_free_rec, -1);
+               if (vfs_dq_alloc_space_nodirty(inode,
+                                      ocfs2_clusters_to_bytes(osb->sb, 1))) {
+                       ret = -EDQUOT;
+                       goto out_commit;
+               }
+               did_quota = 1;
 
-                       /*
-                        * The leftmost record might be an empty extent -
-                        * delete it here too.
-                        */
-                       if (i == 1 && ocfs2_is_empty_extent(&el->l_recs[0])) {
-                               el->l_recs[0].e_cpos = 0;
-                               el->l_recs[0].e_blkno = 0;
-                               el->l_next_free_rec = 0;
-                       }
+               ret = ocfs2_claim_clusters(osb, handle, data_ac, 1, &bit_off,
+                                          &num);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out_commit;
                }
-       }
 
-       if (le32_to_cpu(fe->i_clusters) == 0) {
-               /* trunc to zero is a special case. */
-               el->l_tree_depth = 0;
-               fe->i_last_eb_blk = 0;
-       } else if (last_eb)
-               fe->i_last_eb_blk = last_eb->h_blkno;
+               /*
+                * Save two copies, one for insert, and one that can
+                * be changed by ocfs2_map_and_dirty_page() below.
+                */
+               block = phys = ocfs2_clusters_to_blocks(inode->i_sb, bit_off);
 
-       status = ocfs2_journal_dirty(handle, fe_bh);
-       if (status < 0) {
-               mlog_errno(status);
-               goto bail;
-       }
+               /*
+                * Non sparse file systems zero on extend, so no need
+                * to do that now.
+                */
+               if (!ocfs2_sparse_alloc(osb) &&
+                   PAGE_CACHE_SIZE < osb->s_clustersize)
+                       end = PAGE_CACHE_SIZE;
 
-       if (last_eb) {
-               /* If there will be a new last extent block, then by
-                * definition, there cannot be any leaves to the right of
-                * him. */
-               last_eb->h_next_leaf_blk = 0;
-               status = ocfs2_journal_dirty(handle, last_eb_bh);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
+               ret = ocfs2_grab_eof_pages(inode, 0, end, pages, &num_pages);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out_commit;
                }
-       }
 
-       index = 1;
-       /* if our tree depth > 0, update all the tree blocks below us. */
-       while (index <= path->p_tree_depth) {
-               eb_bh = path->p_node[index].bh;
-               eb = (struct ocfs2_extent_block *)eb_bh->b_data;
-               el = path->p_node[index].el;
+               /*
+                * This should populate the 1st page for us and mark
+                * it up to date.
+                */
+               ret = ocfs2_read_inline_data(inode, pages[0], di_bh);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out_commit;
+               }
 
-               mlog(0, "traveling tree (index = %d, extent block: %llu)\n",
-                    index,  (unsigned long long)eb_bh->b_blocknr);
+               page_end = PAGE_CACHE_SIZE;
+               if (PAGE_CACHE_SIZE > osb->s_clustersize)
+                       page_end = osb->s_clustersize;
 
-               BUG_ON(le16_to_cpu(el->l_next_free_rec) == 0);
-               if (index !=
-                   (path->p_tree_depth - le16_to_cpu(el->l_tree_depth))) {
-                       ocfs2_error(inode->i_sb,
-                                   "Inode %lu has invalid ext. block %llu\n",
-                                   inode->i_ino,
-                                   (unsigned long long)eb_bh->b_blocknr);
-                       goto bail;
-               }
+               for (i = 0; i < num_pages; i++)
+                       ocfs2_map_and_dirty_page(inode, handle, 0, page_end,
+                                                pages[i], i > 0, &phys);
+       }
 
-               i = le16_to_cpu(el->l_next_free_rec) - 1;
+       spin_lock(&oi->ip_lock);
+       oi->ip_dyn_features &= ~OCFS2_INLINE_DATA_FL;
+       di->i_dyn_features = cpu_to_le16(oi->ip_dyn_features);
+       spin_unlock(&oi->ip_lock);
 
-               mlog(0, "extent block %llu, before: record %d: "
-                    "(%u, %u, %llu), next = %u\n",
-                    (unsigned long long)le64_to_cpu(eb->h_blkno), i,
-                    le32_to_cpu(el->l_recs[i].e_cpos),
-                    le32_to_cpu(el->l_recs[i].e_clusters),
-                    (unsigned long long)le64_to_cpu(el->l_recs[i].e_blkno),
-                    le16_to_cpu(el->l_next_free_rec));
+       ocfs2_dinode_new_extent_list(inode, di);
 
-               BUG_ON(le32_to_cpu(el->l_recs[i].e_clusters) < clusters_to_del);
-               le32_add_cpu(&el->l_recs[i].e_clusters, -clusters_to_del);
-
-               /* bottom-most block requires us to delete data.*/
-               if (!el->l_tree_depth)
-                       delete_blk = le64_to_cpu(el->l_recs[i].e_blkno)
-                               + ocfs2_clusters_to_blocks(osb->sb,
-                                       le32_to_cpu(el->l_recs[i].e_clusters));
-               if (!el->l_recs[i].e_clusters) {
-                       el->l_recs[i].e_cpos = 0;
-                       el->l_recs[i].e_blkno = 0;
-                       BUG_ON(!el->l_next_free_rec);
-                       le16_add_cpu(&el->l_next_free_rec, -1);
-               }
-               if (i == 1 && ocfs2_is_empty_extent(&el->l_recs[0])) {
-                       el->l_recs[0].e_cpos = 0;
-                       el->l_recs[0].e_blkno = 0;
-                       el->l_next_free_rec = 0;
-               }
-
-               mlog(0, "extent block %llu, after: record %d: "
-                    "(%u, %u, %llu), next = %u\n",
-                    (unsigned long long)le64_to_cpu(eb->h_blkno), i,
-                    le32_to_cpu(el->l_recs[i].e_cpos),
-                    le32_to_cpu(el->l_recs[i].e_clusters),
-                    (unsigned long long)le64_to_cpu(el->l_recs[i].e_blkno),
-                    le16_to_cpu(el->l_next_free_rec));
+       ocfs2_journal_dirty(handle, di_bh);
 
-               status = ocfs2_journal_dirty(handle, eb_bh);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
+       if (has_data) {
+               /*
+                * An error at this point should be extremely rare. If
+                * this proves to be false, we could always re-build
+                * the in-inode data from our pages.
+                */
+               ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), di_bh);
+               ret = ocfs2_insert_extent(handle, &et, 0, block, 1, 0, NULL);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out_commit;
                }
 
-               if (!el->l_next_free_rec) {
-                       mlog(0, "deleting this extent block.\n");
+               inode->i_blocks = ocfs2_inode_sector_count(inode);
+       }
 
-                       ocfs2_remove_from_cache(inode, eb_bh);
+out_commit:
+       if (ret < 0 && did_quota)
+               vfs_dq_free_space_nodirty(inode,
+                                         ocfs2_clusters_to_bytes(osb->sb, 1));
 
-                       BUG_ON(el->l_recs[0].e_clusters);
-                       BUG_ON(el->l_recs[0].e_cpos);
-                       BUG_ON(el->l_recs[0].e_blkno);
+       ocfs2_commit_trans(osb, handle);
 
-                       /*
-                        * We need to remove this extent block from
-                        * the list above it.
-                        *
-                        * Since we've passed it already in this loop,
-                        * no need to worry about journaling.
-                        */
-                       el = path->p_node[index - 1].el;
-                       i = le16_to_cpu(el->l_next_free_rec) - 1;
-                       BUG_ON(i < 0);
-                       el->l_recs[i].e_cpos = 0;
-                       el->l_recs[i].e_clusters = 0;
-                       el->l_recs[i].e_blkno = 0;
-                       le16_add_cpu(&el->l_next_free_rec, -1);
-
-                       if (eb->h_suballoc_slot == 0) {
-                               /*
-                                * This code only understands how to
-                                * lock the suballocator in slot 0,
-                                * which is fine because allocation is
-                                * only ever done out of that
-                                * suballocator too. A future version
-                                * might change that however, so avoid
-                                * a free if we don't know how to
-                                * handle it. This way an fs incompat
-                                * bit will not be necessary.
-                                */
-                               status = ocfs2_free_extent_block(handle,
-                                                                tc->tc_ext_alloc_inode,
-                                                                tc->tc_ext_alloc_bh,
-                                                                eb);
-                               if (status < 0) {
-                                       mlog_errno(status);
-                                       goto bail;
-                               }
-                       }
-               }
-               index++;
-       }
+out_unlock:
+       if (data_ac)
+               ocfs2_free_alloc_context(data_ac);
 
-       BUG_ON(!delete_blk);
-       status = ocfs2_truncate_log_append(osb, handle, delete_blk,
-                                          clusters_to_del);
-       if (status < 0) {
-               mlog_errno(status);
-               goto bail;
+out:
+       if (pages) {
+               ocfs2_unlock_and_free_pages(pages, num_pages);
+               kfree(pages);
        }
-       status = 0;
-bail:
 
-       mlog_exit(status);
-       return status;
+       return ret;
 }
 
 /*
@@ -3255,29 +7411,45 @@ int ocfs2_commit_truncate(struct ocfs2_super *osb,
 {
        int status, i, credits, tl_sem = 0;
        u32 clusters_to_del, new_highest_cpos, range;
+       u64 blkno = 0;
        struct ocfs2_extent_list *el;
        handle_t *handle = NULL;
        struct inode *tl_inode = osb->osb_tl_inode;
        struct ocfs2_path *path = NULL;
+       struct ocfs2_dinode *di = (struct ocfs2_dinode *)fe_bh->b_data;
+       struct ocfs2_alloc_context *meta_ac = NULL;
+       struct ocfs2_refcount_tree *ref_tree = NULL;
 
        mlog_entry_void();
 
-       down_write(&OCFS2_I(inode)->ip_alloc_sem);
-
        new_highest_cpos = ocfs2_clusters_for_bytes(osb->sb,
                                                     i_size_read(inode));
 
-       path = ocfs2_new_inode_path(fe_bh);
+       path = ocfs2_new_path(fe_bh, &di->id2.i_list,
+                             ocfs2_journal_access_di);
        if (!path) {
                status = -ENOMEM;
                mlog_errno(status);
                goto bail;
        }
+
+       ocfs2_extent_map_trunc(inode, new_highest_cpos);
+
 start:
        /*
+        * Check that we still have allocation to delete.
+        */
+       if (OCFS2_I(inode)->ip_clusters == 0) {
+               status = 0;
+               goto bail;
+       }
+
+       credits = 0;
+
+       /*
         * Truncate always works against the rightmost tree branch.
         */
-       status = ocfs2_find_path(inode, path, UINT_MAX);
+       status = ocfs2_find_path(INODE_CACHE(inode), path, UINT_MAX);
        if (status) {
                mlog_errno(status);
                goto bail;
@@ -3298,17 +7470,31 @@ start:
         * - no record needs to be removed (truncate has completed)
         */
        el = path_leaf_el(path);
+       if (le16_to_cpu(el->l_next_free_rec) == 0) {
+               ocfs2_error(inode->i_sb,
+                           "Inode %llu has empty extent block at %llu\n",
+                           (unsigned long long)OCFS2_I(inode)->ip_blkno,
+                           (unsigned long long)path_leaf_bh(path)->b_blocknr);
+               status = -EROFS;
+               goto bail;
+       }
+
        i = le16_to_cpu(el->l_next_free_rec) - 1;
        range = le32_to_cpu(el->l_recs[i].e_cpos) +
-               le32_to_cpu(el->l_recs[i].e_clusters);
+               ocfs2_rec_clusters(el, &el->l_recs[i]);
        if (i == 0 && ocfs2_is_empty_extent(&el->l_recs[i])) {
                clusters_to_del = 0;
        } else if (le32_to_cpu(el->l_recs[i].e_cpos) >= new_highest_cpos) {
-               clusters_to_del = le32_to_cpu(el->l_recs[i].e_clusters);
+               clusters_to_del = ocfs2_rec_clusters(el, &el->l_recs[i]);
+               blkno = le64_to_cpu(el->l_recs[i].e_blkno);
        } else if (range > new_highest_cpos) {
-               clusters_to_del = (le32_to_cpu(el->l_recs[i].e_clusters) +
+               clusters_to_del = (ocfs2_rec_clusters(el, &el->l_recs[i]) +
                                   le32_to_cpu(el->l_recs[i].e_cpos)) -
                                  new_highest_cpos;
+               blkno = le64_to_cpu(el->l_recs[i].e_blkno) +
+                       ocfs2_clusters_to_blocks(inode->i_sb,
+                               ocfs2_rec_clusters(el, &el->l_recs[i]) -
+                               clusters_to_del);
        } else {
                status = 0;
                goto bail;
@@ -3317,7 +7503,28 @@ start:
        mlog(0, "clusters_to_del = %u in this pass, tail blk=%llu\n",
             clusters_to_del, (unsigned long long)path_leaf_bh(path)->b_blocknr);
 
-       BUG_ON(clusters_to_del == 0);
+       if (el->l_recs[i].e_flags & OCFS2_EXT_REFCOUNTED && clusters_to_del) {
+               BUG_ON(!(OCFS2_I(inode)->ip_dyn_features &
+                        OCFS2_HAS_REFCOUNT_FL));
+
+               status = ocfs2_lock_refcount_tree(osb,
+                                               le64_to_cpu(di->i_refcount_loc),
+                                               1, &ref_tree, NULL);
+               if (status) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+
+               status = ocfs2_prepare_refcount_change_for_del(inode, fe_bh,
+                                                              blkno,
+                                                              clusters_to_del,
+                                                              &credits,
+                                                              &meta_ac);
+               if (status < 0) {
+                       mlog_errno(status);
+                       goto bail;
+               }
+       }
 
        mutex_lock(&tl_inode->i_mutex);
        tl_sem = 1;
@@ -3332,7 +7539,7 @@ start:
                }
        }
 
-       credits = ocfs2_calc_tree_trunc_credits(osb->sb, clusters_to_del,
+       credits += ocfs2_calc_tree_trunc_credits(osb->sb, clusters_to_del,
                                                (struct ocfs2_dinode *)fe_bh->b_data,
                                                el);
        handle = ocfs2_start_trans(osb, credits);
@@ -3344,7 +7551,7 @@ start:
        }
 
        status = ocfs2_do_truncate(osb, clusters_to_del, inode, fe_bh, handle,
-                                  tc, path);
+                                  tc, path, meta_ac);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
@@ -3358,13 +7565,23 @@ start:
 
        ocfs2_reinit_path(path, 1);
 
+       if (meta_ac) {
+               ocfs2_free_alloc_context(meta_ac);
+               meta_ac = NULL;
+       }
+
+       if (ref_tree) {
+               ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
+               ref_tree = NULL;
+       }
+
        /*
-        * Only loop if we still have allocation.
+        * The check above will catch the case where we've truncated
+        * away all allocation.
         */
-       if (OCFS2_I(inode)->ip_clusters)
-               goto start;
+       goto start;
+
 bail:
-       up_write(&OCFS2_I(inode)->ip_alloc_sem);
 
        ocfs2_schedule_truncate_log_flush(osb, 1);
 
@@ -3374,6 +7591,14 @@ bail:
        if (handle)
                ocfs2_commit_trans(osb, handle);
 
+       if (meta_ac)
+               ocfs2_free_alloc_context(meta_ac);
+
+       if (ref_tree)
+               ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
+
+       ocfs2_run_deallocs(osb, &tc->tc_dealloc);
+
        ocfs2_free_path(path);
 
        /* This will drop the ext_alloc cluster lock for us */
@@ -3384,23 +7609,18 @@ bail:
 }
 
 /*
- * Expects the inode to already be locked. This will figure out which
- * inodes need to be locked and will put them on the returned truncate
- * context.
+ * Expects the inode to already be locked.
  */
 int ocfs2_prepare_truncate(struct ocfs2_super *osb,
                           struct inode *inode,
                           struct buffer_head *fe_bh,
                           struct ocfs2_truncate_context **tc)
 {
-       int status, metadata_delete, i;
+       int status;
        unsigned int new_i_clusters;
        struct ocfs2_dinode *fe;
        struct ocfs2_extent_block *eb;
-       struct ocfs2_extent_list *el;
        struct buffer_head *last_eb_bh = NULL;
-       struct inode *ext_alloc_inode = NULL;
-       struct buffer_head *ext_alloc_bh = NULL;
 
        mlog_entry_void();
 
@@ -3411,24 +7631,8 @@ int ocfs2_prepare_truncate(struct ocfs2_super *osb,
        fe = (struct ocfs2_dinode *) fe_bh->b_data;
 
        mlog(0, "fe->i_clusters = %u, new_i_clusters = %u, fe->i_size ="
-            "%llu\n", fe->i_clusters, new_i_clusters,
-            (unsigned long long)fe->i_size);
-
-       if (!ocfs2_sparse_alloc(osb) &&
-           le32_to_cpu(fe->i_clusters) <= new_i_clusters) {
-               ocfs2_error(inode->i_sb, "Dinode %llu has cluster count "
-                           "%u and size %llu whereas struct inode has "
-                           "cluster count %u and size %llu which caused an "
-                           "invalid truncate to %u clusters.",
-                           (unsigned long long)le64_to_cpu(fe->i_blkno),
-                           le32_to_cpu(fe->i_clusters),
-                           (unsigned long long)le64_to_cpu(fe->i_size),
-                           OCFS2_I(inode)->ip_clusters, i_size_read(inode),
-                           new_i_clusters);
-               mlog_meta_lvb(ML_ERROR, &OCFS2_I(inode)->ip_meta_lockres);
-               status = -EIO;
-               goto bail;
-       }
+            "%llu\n", le32_to_cpu(fe->i_clusters), new_i_clusters,
+            (unsigned long long)le64_to_cpu(fe->i_size));
 
        *tc = kzalloc(sizeof(struct ocfs2_truncate_context), GFP_KERNEL);
        if (!(*tc)) {
@@ -3436,63 +7640,21 @@ int ocfs2_prepare_truncate(struct ocfs2_super *osb,
                mlog_errno(status);
                goto bail;
        }
+       ocfs2_init_dealloc_ctxt(&(*tc)->tc_dealloc);
 
-       metadata_delete = 0;
        if (fe->id2.i_list.l_tree_depth) {
-               /* If we have a tree, then the truncate may result in
-                * metadata deletes. Figure this out from the
-                * rightmost leaf block.*/
-               status = ocfs2_read_block(osb, le64_to_cpu(fe->i_last_eb_blk),
-                                         &last_eb_bh, OCFS2_BH_CACHED, inode);
+               status = ocfs2_read_extent_block(INODE_CACHE(inode),
+                                                le64_to_cpu(fe->i_last_eb_blk),
+                                                &last_eb_bh);
                if (status < 0) {
                        mlog_errno(status);
                        goto bail;
                }
                eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
-               if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
-                       OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
-
-                       brelse(last_eb_bh);
-                       status = -EIO;
-                       goto bail;
-               }
-               el = &(eb->h_list);
-
-               i = 0;
-               if (ocfs2_is_empty_extent(&el->l_recs[0]))
-                       i = 1;
-               /*
-                * XXX: Should we check that next_free_rec contains
-                * the extent?
-                */
-               if (le32_to_cpu(el->l_recs[i].e_cpos) >= new_i_clusters)
-                       metadata_delete = 1;
        }
 
        (*tc)->tc_last_eb_bh = last_eb_bh;
 
-       if (metadata_delete) {
-               mlog(0, "Will have to delete metadata for this trunc. "
-                    "locking allocator.\n");
-               ext_alloc_inode = ocfs2_get_system_file_inode(osb, EXTENT_ALLOC_SYSTEM_INODE, 0);
-               if (!ext_alloc_inode) {
-                       status = -ENOMEM;
-                       mlog_errno(status);
-                       goto bail;
-               }
-
-               mutex_lock(&ext_alloc_inode->i_mutex);
-               (*tc)->tc_ext_alloc_inode = ext_alloc_inode;
-
-               status = ocfs2_meta_lock(ext_alloc_inode, &ext_alloc_bh, 1);
-               if (status < 0) {
-                       mlog_errno(status);
-                       goto bail;
-               }
-               (*tc)->tc_ext_alloc_bh = ext_alloc_bh;
-               (*tc)->tc_ext_alloc_locked = 1;
-       }
-
        status = 0;
 bail:
        if (status < 0) {
@@ -3504,21 +7666,92 @@ bail:
        return status;
 }
 
-static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc)
+/*
+ * 'start' is inclusive, 'end' is not.
+ */
+int ocfs2_truncate_inline(struct inode *inode, struct buffer_head *di_bh,
+                         unsigned int start, unsigned int end, int trunc)
 {
-       if (tc->tc_ext_alloc_inode) {
-               if (tc->tc_ext_alloc_locked)
-                       ocfs2_meta_unlock(tc->tc_ext_alloc_inode, 1);
+       int ret;
+       unsigned int numbytes;
+       handle_t *handle;
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+       struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
+       struct ocfs2_inline_data *idata = &di->id2.i_data;
+
+       if (end > i_size_read(inode))
+               end = i_size_read(inode);
+
+       BUG_ON(start >= end);
 
-               mutex_unlock(&tc->tc_ext_alloc_inode->i_mutex);
-               iput(tc->tc_ext_alloc_inode);
+       if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) ||
+           !(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL) ||
+           !ocfs2_supports_inline_data(osb)) {
+               ocfs2_error(inode->i_sb,
+                           "Inline data flags for inode %llu don't agree! "
+                           "Disk: 0x%x, Memory: 0x%x, Superblock: 0x%x\n",
+                           (unsigned long long)OCFS2_I(inode)->ip_blkno,
+                           le16_to_cpu(di->i_dyn_features),
+                           OCFS2_I(inode)->ip_dyn_features,
+                           osb->s_feature_incompat);
+               ret = -EROFS;
+               goto out;
+       }
+
+       handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
+       if (IS_ERR(handle)) {
+               ret = PTR_ERR(handle);
+               mlog_errno(ret);
+               goto out;
+       }
+
+       ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
+                                     OCFS2_JOURNAL_ACCESS_WRITE);
+       if (ret) {
+               mlog_errno(ret);
+               goto out_commit;
+       }
+
+       numbytes = end - start;
+       memset(idata->id_data + start, 0, numbytes);
+
+       /*
+        * No need to worry about the data page here - it's been
+        * truncated already and inline data doesn't need it for
+        * pushing zero's to disk, so we'll let readpage pick it up
+        * later.
+        */
+       if (trunc) {
+               i_size_write(inode, start);
+               di->i_size = cpu_to_le64(start);
        }
 
-       if (tc->tc_ext_alloc_bh)
-               brelse(tc->tc_ext_alloc_bh);
+       inode->i_blocks = ocfs2_inode_sector_count(inode);
+       inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+       di->i_ctime = di->i_mtime = cpu_to_le64(inode->i_ctime.tv_sec);
+       di->i_ctime_nsec = di->i_mtime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
+
+       ocfs2_journal_dirty(handle, di_bh);
+
+out_commit:
+       ocfs2_commit_trans(osb, handle);
+
+out:
+       return ret;
+}
+
+static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc)
+{
+       /*
+        * The caller is responsible for completing deallocation
+        * before freeing the context.
+        */
+       if (tc->tc_dealloc.c_first_suballocator != NULL)
+               mlog(ML_NOTICE,
+                    "Truncate completion has non-empty dealloc context\n");
 
-       if (tc->tc_last_eb_bh)
-               brelse(tc->tc_last_eb_bh);
+       brelse(tc->tc_last_eb_bh);
 
        kfree(tc);
 }