fs: symlink write_begin allocation context fix
[safe/jmp/linux-2.6] / fs / ext4 / extents.c
index e06e937..ea2ce3c 100644 (file)
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/time.h>
-#include <linux/ext4_jbd2.h>
-#include <linux/jbd.h>
-#include <linux/smp_lock.h>
+#include <linux/jbd2.h>
 #include <linux/highuid.h>
 #include <linux/pagemap.h>
 #include <linux/quotaops.h>
 #include <linux/string.h>
 #include <linux/slab.h>
-#include <linux/ext4_fs_extents.h>
+#include <linux/falloc.h>
 #include <asm/uaccess.h>
+#include <linux/fiemap.h>
+#include "ext4_jbd2.h"
+#include "ext4_extents.h"
 
 
 /*
  * ext_pblock:
  * combine low and high parts of physical block number into ext4_fsblk_t
  */
-static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
+static ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
 {
        ext4_fsblk_t block;
 
-       block = le32_to_cpu(ex->ee_start);
-       if (sizeof(ext4_fsblk_t) > 4)
-               block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1;
+       block = le32_to_cpu(ex->ee_start_lo);
+       block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1;
        return block;
 }
 
@@ -62,13 +62,12 @@ static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
  * idx_pblock:
  * combine low and high parts of a leaf physical block number into ext4_fsblk_t
  */
-static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
+ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
 {
        ext4_fsblk_t block;
 
-       block = le32_to_cpu(ix->ei_leaf);
-       if (sizeof(ext4_fsblk_t) > 4)
-               block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1;
+       block = le32_to_cpu(ix->ei_leaf_lo);
+       block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1;
        return block;
 }
 
@@ -77,11 +76,10 @@ static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
  * stores a large physical block number into an extent struct,
  * breaking it into parts
  */
-static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
+void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
 {
-       ex->ee_start = cpu_to_le32((unsigned long) (pb & 0xffffffff));
-       if (sizeof(ext4_fsblk_t) > 4)
-               ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
+       ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
+       ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
 }
 
 /*
@@ -89,54 +87,22 @@ static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb
  * stores a large physical block number into an index struct,
  * breaking it into parts
  */
-static inline void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
+static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
 {
-       ix->ei_leaf = cpu_to_le32((unsigned long) (pb & 0xffffffff));
-       if (sizeof(ext4_fsblk_t) > 4)
-               ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
+       ix->ei_leaf_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
+       ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
 }
 
-static int ext4_ext_check_header(const char *function, struct inode *inode,
-                               struct ext4_extent_header *eh)
-{
-       const char *error_msg = NULL;
-
-       if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
-               error_msg = "invalid magic";
-               goto corrupted;
-       }
-       if (unlikely(eh->eh_max == 0)) {
-               error_msg = "invalid eh_max";
-               goto corrupted;
-       }
-       if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
-               error_msg = "invalid eh_entries";
-               goto corrupted;
-       }
-       return 0;
-
-corrupted:
-       ext4_error(inode->i_sb, function,
-                       "bad header in inode #%lu: %s - magic %x, "
-                       "entries %u, max %u, depth %u",
-                       inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
-                       le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
-                       le16_to_cpu(eh->eh_depth));
-
-       return -EIO;
-}
-
-static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed)
+static int ext4_ext_journal_restart(handle_t *handle, int needed)
 {
        int err;
 
        if (handle->h_buffer_credits > needed)
-               return handle;
-       if (!ext4_journal_extend(handle, needed))
-               return handle;
-       err = ext4_journal_restart(handle, needed);
-
-       return handle;
+               return 0;
+       err = ext4_journal_extend(handle, needed);
+       if (err <= 0)
+               return err;
+       return ext4_journal_restart(handle, needed);
 }
 
 /*
@@ -178,10 +144,11 @@ static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
 
 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
                              struct ext4_ext_path *path,
-                             ext4_fsblk_t block)
+                             ext4_lblk_t block)
 {
        struct ext4_inode_info *ei = EXT4_I(inode);
        ext4_fsblk_t bg_start;
+       ext4_fsblk_t last_block;
        ext4_grpblk_t colour;
        int depth;
 
@@ -190,7 +157,8 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
                depth = path->p_depth;
 
                /* try to predict block placement */
-               if ((ex = path[depth].p_ext))
+               ex = path[depth].p_ext;
+               if (ex)
                        return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block));
 
                /* it looks like index is empty;
@@ -202,77 +170,179 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
        /* OK. use inode's group */
        bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) +
                le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block);
-       colour = (current->pid % 16) *
+       last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
+
+       if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
+               colour = (current->pid % 16) *
                        (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
+       else
+               colour = (current->pid % 16) * ((last_block - bg_start) / 16);
        return bg_start + colour + block;
 }
 
+/*
+ * Allocation for a meta data block
+ */
 static ext4_fsblk_t
-ext4_ext_new_block(handle_t *handle, struct inode *inode,
+ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
                        struct ext4_ext_path *path,
                        struct ext4_extent *ex, int *err)
 {
        ext4_fsblk_t goal, newblock;
 
        goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
-       newblock = ext4_new_block(handle, inode, goal, err);
+       newblock = ext4_new_meta_block(handle, inode, goal, err);
        return newblock;
 }
 
-static inline int ext4_ext_space_block(struct inode *inode)
+static int ext4_ext_space_block(struct inode *inode)
 {
        int size;
 
        size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
                        / sizeof(struct ext4_extent);
-#ifdef AGRESSIVE_TEST
+#ifdef AGGRESSIVE_TEST
        if (size > 6)
                size = 6;
 #endif
        return size;
 }
 
-static inline int ext4_ext_space_block_idx(struct inode *inode)
+static int ext4_ext_space_block_idx(struct inode *inode)
 {
        int size;
 
        size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
                        / sizeof(struct ext4_extent_idx);
-#ifdef AGRESSIVE_TEST
+#ifdef AGGRESSIVE_TEST
        if (size > 5)
                size = 5;
 #endif
        return size;
 }
 
-static inline int ext4_ext_space_root(struct inode *inode)
+static int ext4_ext_space_root(struct inode *inode)
 {
        int size;
 
        size = sizeof(EXT4_I(inode)->i_data);
        size -= sizeof(struct ext4_extent_header);
        size /= sizeof(struct ext4_extent);
-#ifdef AGRESSIVE_TEST
+#ifdef AGGRESSIVE_TEST
        if (size > 3)
                size = 3;
 #endif
        return size;
 }
 
-static inline int ext4_ext_space_root_idx(struct inode *inode)
+static int ext4_ext_space_root_idx(struct inode *inode)
 {
        int size;
 
        size = sizeof(EXT4_I(inode)->i_data);
        size -= sizeof(struct ext4_extent_header);
        size /= sizeof(struct ext4_extent_idx);
-#ifdef AGRESSIVE_TEST
+#ifdef AGGRESSIVE_TEST
        if (size > 4)
                size = 4;
 #endif
        return size;
 }
 
+/*
+ * Calculate the number of metadata blocks needed
+ * to allocate @blocks
+ * Worse case is one block per extent
+ */
+int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
+{
+       int lcap, icap, rcap, leafs, idxs, num;
+       int newextents = blocks;
+
+       rcap = ext4_ext_space_root_idx(inode);
+       lcap = ext4_ext_space_block(inode);
+       icap = ext4_ext_space_block_idx(inode);
+
+       /* number of new leaf blocks needed */
+       num = leafs = (newextents + lcap - 1) / lcap;
+
+       /*
+        * Worse case, we need separate index block(s)
+        * to link all new leaf blocks
+        */
+       idxs = (leafs + icap - 1) / icap;
+       do {
+               num += idxs;
+               idxs = (idxs + icap - 1) / icap;
+       } while (idxs > rcap);
+
+       return num;
+}
+
+static int
+ext4_ext_max_entries(struct inode *inode, int depth)
+{
+       int max;
+
+       if (depth == ext_depth(inode)) {
+               if (depth == 0)
+                       max = ext4_ext_space_root(inode);
+               else
+                       max = ext4_ext_space_root_idx(inode);
+       } else {
+               if (depth == 0)
+                       max = ext4_ext_space_block(inode);
+               else
+                       max = ext4_ext_space_block_idx(inode);
+       }
+
+       return max;
+}
+
+static int __ext4_ext_check_header(const char *function, struct inode *inode,
+                                       struct ext4_extent_header *eh,
+                                       int depth)
+{
+       const char *error_msg;
+       int max = 0;
+
+       if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
+               error_msg = "invalid magic";
+               goto corrupted;
+       }
+       if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
+               error_msg = "unexpected eh_depth";
+               goto corrupted;
+       }
+       if (unlikely(eh->eh_max == 0)) {
+               error_msg = "invalid eh_max";
+               goto corrupted;
+       }
+       max = ext4_ext_max_entries(inode, depth);
+       if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
+               error_msg = "too large eh_max";
+               goto corrupted;
+       }
+       if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
+               error_msg = "invalid eh_entries";
+               goto corrupted;
+       }
+       return 0;
+
+corrupted:
+       ext4_error(inode->i_sb, function,
+                       "bad header in inode #%lu: %s - magic %x, "
+                       "entries %u, max %u(%u), depth %u(%u)",
+                       inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
+                       le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
+                       max, le16_to_cpu(eh->eh_depth), depth);
+
+       return -EIO;
+}
+
+#define ext4_ext_check_header(inode, eh, depth)        \
+       __ext4_ext_check_header(__func__, inode, eh, depth)
+
 #ifdef EXT_DEBUG
 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 {
@@ -281,12 +351,12 @@ static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
        ext_debug("path:");
        for (k = 0; k <= l; k++, path++) {
                if (path->p_idx) {
-                 ext_debug("  %d->"E3FSBLK, le32_to_cpu(path->p_idx->ei_block),
+                 ext_debug("  %d->%llu", le32_to_cpu(path->p_idx->ei_block),
                            idx_pblock(path->p_idx));
                } else if (path->p_ext) {
-                       ext_debug("  %d:%d:"E3FSBLK" ",
+                       ext_debug("  %d:%d:%llu ",
                                  le32_to_cpu(path->p_ext->ee_block),
-                                 le16_to_cpu(path->p_ext->ee_len),
+                                 ext4_ext_get_actual_len(path->p_ext),
                                  ext_pblock(path->p_ext));
                } else
                        ext_debug("  []");
@@ -308,17 +378,17 @@ static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
        ex = EXT_FIRST_EXTENT(eh);
 
        for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
-               ext_debug("%d:%d:"E3FSBLK" ", le32_to_cpu(ex->ee_block),
-                         le16_to_cpu(ex->ee_len), ext_pblock(ex));
+               ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block),
+                         ext4_ext_get_actual_len(ex), ext_pblock(ex));
        }
        ext_debug("\n");
 }
 #else
-#define ext4_ext_show_path(inode,path)
-#define ext4_ext_show_leaf(inode,path)
+#define ext4_ext_show_path(inode, path)
+#define ext4_ext_show_leaf(inode, path)
 #endif
 
-static void ext4_ext_drop_refs(struct ext4_ext_path *path)
+void ext4_ext_drop_refs(struct ext4_ext_path *path)
 {
        int depth = path->p_depth;
        int i;
@@ -333,34 +403,34 @@ static void ext4_ext_drop_refs(struct ext4_ext_path *path)
 /*
  * ext4_ext_binsearch_idx:
  * binary search for the closest index of the given block
+ * the header must be checked before calling this
  */
 static void
-ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block)
+ext4_ext_binsearch_idx(struct inode *inode,
+                       struct ext4_ext_path *path, ext4_lblk_t block)
 {
        struct ext4_extent_header *eh = path->p_hdr;
        struct ext4_extent_idx *r, *l, *m;
 
-       BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
-       BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
-       BUG_ON(le16_to_cpu(eh->eh_entries) <= 0);
 
-       ext_debug("binsearch for %d(idx):  ", block);
+       ext_debug("binsearch for %u(idx):  ", block);
 
        l = EXT_FIRST_INDEX(eh) + 1;
-       r = EXT_FIRST_INDEX(eh) + le16_to_cpu(eh->eh_entries) - 1;
+       r = EXT_LAST_INDEX(eh);
        while (l <= r) {
                m = l + (r - l) / 2;
                if (block < le32_to_cpu(m->ei_block))
                        r = m - 1;
                else
                        l = m + 1;
-               ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ei_block,
-                               m, m->ei_block, r, r->ei_block);
+               ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
+                               m, le32_to_cpu(m->ei_block),
+                               r, le32_to_cpu(r->ei_block));
        }
 
        path->p_idx = l - 1;
        ext_debug("  -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
-                 idx_block(path->p_idx));
+                 idx_pblock(path->p_idx));
 
 #ifdef CHECK_BINSEARCH
        {
@@ -371,14 +441,15 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc
                for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
                  if (k != 0 &&
                      le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
-                               printk("k=%d, ix=0x%p, first=0x%p\n", k,
-                                       ix, EXT_FIRST_INDEX(eh));
-                               printk("%u <= %u\n",
+                               printk(KERN_DEBUG "k=%d, ix=0x%p, "
+                                      "first=0x%p\n", k,
+                                      ix, EXT_FIRST_INDEX(eh));
+                               printk(KERN_DEBUG "%u <= %u\n",
                                       le32_to_cpu(ix->ei_block),
                                       le32_to_cpu(ix[-1].ei_block));
                        }
                        BUG_ON(k && le32_to_cpu(ix->ei_block)
-                                          <= le32_to_cpu(ix[-1].ei_block));
+                                          <= le32_to_cpu(ix[-1].ei_block));
                        if (block < le32_to_cpu(ix->ei_block))
                                break;
                        chix = ix;
@@ -392,16 +463,15 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc
 /*
  * ext4_ext_binsearch:
  * binary search for closest extent of the given block
+ * the header must be checked before calling this
  */
 static void
-ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
+ext4_ext_binsearch(struct inode *inode,
+               struct ext4_ext_path *path, ext4_lblk_t block)
 {
        struct ext4_extent_header *eh = path->p_hdr;
        struct ext4_extent *r, *l, *m;
 
-       BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
-       BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
-
        if (eh->eh_entries == 0) {
                /*
                 * this leaf is empty:
@@ -410,10 +480,10 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
                return;
        }
 
-       ext_debug("binsearch for %d:  ", block);
+       ext_debug("binsearch for %u:  ", block);
 
        l = EXT_FIRST_EXTENT(eh) + 1;
-       r = EXT_FIRST_EXTENT(eh) + le16_to_cpu(eh->eh_entries) - 1;
+       r = EXT_LAST_EXTENT(eh);
 
        while (l <= r) {
                m = l + (r - l) / 2;
@@ -421,15 +491,16 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
                        r = m - 1;
                else
                        l = m + 1;
-               ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ee_block,
-                               m, m->ee_block, r, r->ee_block);
+               ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
+                               m, le32_to_cpu(m->ee_block),
+                               r, le32_to_cpu(r->ee_block));
        }
 
        path->p_ext = l - 1;
-       ext_debug("  -> %d:"E3FSBLK":%d ",
-                       le32_to_cpu(path->p_ext->ee_block),
-                       ext_pblock(path->p_ext),
-                       le16_to_cpu(path->p_ext->ee_len));
+       ext_debug("  -> %d:%llu:%d ",
+                       le32_to_cpu(path->p_ext->ee_block),
+                       ext_pblock(path->p_ext),
+                       ext4_ext_get_actual_len(path->p_ext));
 
 #ifdef CHECK_BINSEARCH
        {
@@ -439,7 +510,7 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
                chex = ex = EXT_FIRST_EXTENT(eh);
                for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
                        BUG_ON(k && le32_to_cpu(ex->ee_block)
-                                         <= le32_to_cpu(ex[-1].ee_block));
+                                         <= le32_to_cpu(ex[-1].ee_block));
                        if (block < le32_to_cpu(ex->ee_block))
                                break;
                        chex = ex;
@@ -465,34 +536,36 @@ int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
 }
 
 struct ext4_ext_path *
-ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
+ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
+                                       struct ext4_ext_path *path)
 {
        struct ext4_extent_header *eh;
        struct buffer_head *bh;
        short int depth, i, ppos = 0, alloc = 0;
 
        eh = ext_inode_hdr(inode);
-       BUG_ON(eh == NULL);
-       if (ext4_ext_check_header(__FUNCTION__, inode, eh))
+       depth = ext_depth(inode);
+       if (ext4_ext_check_header(inode, eh, depth))
                return ERR_PTR(-EIO);
 
-       i = depth = ext_depth(inode);
 
        /* account possible depth increase */
        if (!path) {
-               path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 2),
+               path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
                                GFP_NOFS);
                if (!path)
                        return ERR_PTR(-ENOMEM);
                alloc = 1;
        }
-       memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1));
        path[0].p_hdr = eh;
+       path[0].p_bh = NULL;
 
+       i = depth;
        /* walk through the tree */
        while (i) {
                ext_debug("depth %d: num %d, max %d\n",
                          ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+
                ext4_ext_binsearch_idx(inode, path + ppos, block);
                path[ppos].p_block = idx_pblock(path[ppos].p_idx);
                path[ppos].p_depth = i;
@@ -509,20 +582,19 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
                path[ppos].p_hdr = eh;
                i--;
 
-               if (ext4_ext_check_header(__FUNCTION__, inode, eh))
+               if (ext4_ext_check_header(inode, eh, i))
                        goto err;
        }
 
        path[ppos].p_depth = i;
-       path[ppos].p_hdr = eh;
        path[ppos].p_ext = NULL;
        path[ppos].p_idx = NULL;
 
-       if (ext4_ext_check_header(__FUNCTION__, inode, eh))
-               goto err;
-
        /* find extent */
        ext4_ext_binsearch(inode, path + ppos, block);
+       /* if not an empty leaf */
+       if (path[ppos].p_ext)
+               path[ppos].p_block = ext_pblock(path[ppos].p_ext);
 
        ext4_ext_show_path(inode, path);
 
@@ -547,7 +619,8 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
        struct ext4_extent_idx *ix;
        int len, err;
 
-       if ((err = ext4_ext_get_access(handle, inode, curp)))
+       err = ext4_ext_get_access(handle, inode, curp);
+       if (err)
                return err;
 
        BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block));
@@ -557,7 +630,7 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
                if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
                        len = (len - 1) * sizeof(struct ext4_extent_idx);
                        len = len < 0 ? 0 : len;
-                       ext_debug("insert new index %d after: %d. "
+                       ext_debug("insert new index %d after: %llu. "
                                        "move %d from 0x%p to 0x%p\n",
                                        logical, ptr, len,
                                        (curp->p_idx + 1), (curp->p_idx + 2));
@@ -568,7 +641,7 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
                /* insert before */
                len = len * sizeof(struct ext4_extent_idx);
                len = len < 0 ? 0 : len;
-               ext_debug("insert new index %d before: %d. "
+               ext_debug("insert new index %d before: %llu. "
                                "move %d from 0x%p to 0x%p\n",
                                logical, ptr, len,
                                curp->p_idx, (curp->p_idx + 1));
@@ -578,10 +651,10 @@ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
 
        ix->ei_block = cpu_to_le32(logical);
        ext4_idx_store_pblock(ix, ptr);
-       curp->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(curp->p_hdr->eh_entries)+1);
+       le16_add_cpu(&curp->p_hdr->eh_entries, 1);
 
        BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries)
-                            > le16_to_cpu(curp->p_hdr->eh_max));
+                            > le16_to_cpu(curp->p_hdr->eh_max));
        BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr));
 
        err = ext4_ext_dirty(handle, inode, curp);
@@ -625,12 +698,12 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                border = path[depth].p_ext[1].ee_block;
                ext_debug("leaf will be split."
                                " next leaf starts at %d\n",
-                                 le32_to_cpu(border));
+                                 le32_to_cpu(border));
        } else {
                border = newext->ee_block;
                ext_debug("leaf will be added."
                                " next leaf starts at %d\n",
-                               le32_to_cpu(border));
+                               le32_to_cpu(border));
        }
 
        /*
@@ -645,15 +718,15 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
         * We need this to handle errors and free blocks
         * upon them.
         */
-       ablocks = kmalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
+       ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
        if (!ablocks)
                return -ENOMEM;
-       memset(ablocks, 0, sizeof(ext4_fsblk_t) * depth);
 
        /* allocate all needed blocks */
        ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
        for (a = 0; a < depth - at; a++) {
-               newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
+               newblock = ext4_ext_new_meta_block(handle, inode, path,
+                                                  newext, &err);
                if (newblock == 0)
                        goto cleanup;
                ablocks[a] = newblock;
@@ -669,7 +742,8 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        }
        lock_buffer(bh);
 
-       if ((err = ext4_journal_get_create_access(handle, bh)))
+       err = ext4_journal_get_create_access(handle, bh);
+       if (err)
                goto cleanup;
 
        neh = ext_block_hdr(bh);
@@ -687,10 +761,10 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        path[depth].p_ext++;
        while (path[depth].p_ext <=
                        EXT_MAX_EXTENT(path[depth].p_hdr)) {
-               ext_debug("move %d:"E3FSBLK":%d in new leaf "E3FSBLK"\n",
-                               le32_to_cpu(path[depth].p_ext->ee_block),
-                               ext_pblock(path[depth].p_ext),
-                               le16_to_cpu(path[depth].p_ext->ee_len),
+               ext_debug("move %d:%llu:%d in new leaf %llu\n",
+                               le32_to_cpu(path[depth].p_ext->ee_block),
+                               ext_pblock(path[depth].p_ext),
+                               ext4_ext_get_actual_len(path[depth].p_ext),
                                newblock);
                /*memmove(ex++, path[depth].p_ext++,
                                sizeof(struct ext4_extent));
@@ -700,24 +774,26 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        }
        if (m) {
                memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m);
-               neh->eh_entries = cpu_to_le16(le16_to_cpu(neh->eh_entries)+m);
+               le16_add_cpu(&neh->eh_entries, m);
        }
 
        set_buffer_uptodate(bh);
        unlock_buffer(bh);
 
-       if ((err = ext4_journal_dirty_metadata(handle, bh)))
+       err = ext4_journal_dirty_metadata(handle, bh);
+       if (err)
                goto cleanup;
        brelse(bh);
        bh = NULL;
 
        /* correct old leaf */
        if (m) {
-               if ((err = ext4_ext_get_access(handle, inode, path + depth)))
+               err = ext4_ext_get_access(handle, inode, path + depth);
+               if (err)
                        goto cleanup;
-               path[depth].p_hdr->eh_entries =
-                    cpu_to_le16(le16_to_cpu(path[depth].p_hdr->eh_entries)-m);
-               if ((err = ext4_ext_dirty(handle, inode, path + depth)))
+               le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
+               err = ext4_ext_dirty(handle, inode, path + depth);
+               if (err)
                        goto cleanup;
 
        }
@@ -733,14 +809,15 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        while (k--) {
                oldblock = newblock;
                newblock = ablocks[--a];
-               bh = sb_getblk(inode->i_sb, (ext4_fsblk_t)newblock);
+               bh = sb_getblk(inode->i_sb, newblock);
                if (!bh) {
                        err = -EIO;
                        goto cleanup;
                }
                lock_buffer(bh);
 
-               if ((err = ext4_journal_get_create_access(handle, bh)))
+               err = ext4_journal_get_create_access(handle, bh);
+               if (err)
                        goto cleanup;
 
                neh = ext_block_hdr(bh);
@@ -752,9 +829,8 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                fidx->ei_block = border;
                ext4_idx_store_pblock(fidx, oldblock);
 
-               ext_debug("int.index at %d (block "E3FSBLK"): %lu -> "E3FSBLK"\n", i,
-                               newblock, (unsigned long) le32_to_cpu(border),
-                               oldblock);
+               ext_debug("int.index at %d (block %llu): %u -> %llu\n",
+                               i, newblock, le32_to_cpu(border), oldblock);
                /* copy indexes */
                m = 0;
                path[i].p_idx++;
@@ -764,10 +840,10 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) !=
                                EXT_LAST_INDEX(path[i].p_hdr));
                while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
-                       ext_debug("%d: move %d:%d in new index "E3FSBLK"\n", i,
-                                       le32_to_cpu(path[i].p_idx->ei_block),
-                                       idx_pblock(path[i].p_idx),
-                                       newblock);
+                       ext_debug("%d: move %d:%llu in new index %llu\n", i,
+                                       le32_to_cpu(path[i].p_idx->ei_block),
+                                       idx_pblock(path[i].p_idx),
+                                       newblock);
                        /*memmove(++fidx, path[i].p_idx++,
                                        sizeof(struct ext4_extent_idx));
                        neh->eh_entries++;
@@ -778,13 +854,13 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                if (m) {
                        memmove(++fidx, path[i].p_idx - m,
                                sizeof(struct ext4_extent_idx) * m);
-                       neh->eh_entries =
-                               cpu_to_le16(le16_to_cpu(neh->eh_entries) + m);
+                       le16_add_cpu(&neh->eh_entries, m);
                }
                set_buffer_uptodate(bh);
                unlock_buffer(bh);
 
-               if ((err = ext4_journal_dirty_metadata(handle, bh)))
+               err = ext4_journal_dirty_metadata(handle, bh);
+               if (err)
                        goto cleanup;
                brelse(bh);
                bh = NULL;
@@ -794,7 +870,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                        err = ext4_ext_get_access(handle, inode, path + i);
                        if (err)
                                goto cleanup;
-                       path[i].p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path[i].p_hdr->eh_entries)-m);
+                       le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
                        err = ext4_ext_dirty(handle, inode, path + i);
                        if (err)
                                goto cleanup;
@@ -804,9 +880,6 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        }
 
        /* insert new index */
-       if (err)
-               goto cleanup;
-
        err = ext4_ext_insert_index(handle, inode, path + at,
                                    le32_to_cpu(border), newblock);
 
@@ -822,7 +895,7 @@ cleanup:
                for (i = 0; i < depth; i++) {
                        if (!ablocks[i])
                                continue;
-                       ext4_free_blocks(handle, inode, ablocks[i], 1);
+                       ext4_free_blocks(handle, inode, ablocks[i], 1, 1);
                }
        }
        kfree(ablocks);
@@ -849,7 +922,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
        ext4_fsblk_t newblock;
        int err = 0;
 
-       newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
+       newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err);
        if (newblock == 0)
                return err;
 
@@ -861,7 +934,8 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
        }
        lock_buffer(bh);
 
-       if ((err = ext4_journal_get_create_access(handle, bh))) {
+       err = ext4_journal_get_create_access(handle, bh);
+       if (err) {
                unlock_buffer(bh);
                goto out;
        }
@@ -881,24 +955,31 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
        set_buffer_uptodate(bh);
        unlock_buffer(bh);
 
-       if ((err = ext4_journal_dirty_metadata(handle, bh)))
+       err = ext4_journal_dirty_metadata(handle, bh);
+       if (err)
                goto out;
 
        /* create index in new top-level index: num,max,pointer */
-       if ((err = ext4_ext_get_access(handle, inode, curp)))
+       err = ext4_ext_get_access(handle, inode, curp);
+       if (err)
                goto out;
 
        curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
        curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
        curp->p_hdr->eh_entries = cpu_to_le16(1);
        curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
-       /* FIXME: it works, but actually path[0] can be index */
-       curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
+
+       if (path[0].p_hdr->eh_depth)
+               curp->p_idx->ei_block =
+                       EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
+       else
+               curp->p_idx->ei_block =
+                       EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
        ext4_idx_store_pblock(curp->p_idx, newblock);
 
        neh = ext_inode_hdr(inode);
        fidx = EXT_FIRST_INDEX(neh);
-       ext_debug("new root: num %d(%d), lblock %d, ptr "E3FSBLK"\n",
+       ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
                  le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
                  le32_to_cpu(fidx->ei_block), idx_pblock(fidx));
 
@@ -938,12 +1019,14 @@ repeat:
                /* if we found index with free entry, then use that
                 * entry: create all needed subtree and add new leaf */
                err = ext4_ext_split(handle, inode, path, newext, i);
+               if (err)
+                       goto out;
 
                /* refill path */
                ext4_ext_drop_refs(path);
                path = ext4_ext_find_extent(inode,
-                                           le32_to_cpu(newext->ee_block),
-                                           path);
+                                   (ext4_lblk_t)le32_to_cpu(newext->ee_block),
+                                   path);
                if (IS_ERR(path))
                        err = PTR_ERR(path);
        } else {
@@ -955,8 +1038,8 @@ repeat:
                /* refill path */
                ext4_ext_drop_refs(path);
                path = ext4_ext_find_extent(inode,
-                                           le32_to_cpu(newext->ee_block),
-                                           path);
+                                  (ext4_lblk_t)le32_to_cpu(newext->ee_block),
+                                   path);
                if (IS_ERR(path)) {
                        err = PTR_ERR(path);
                        goto out;
@@ -978,13 +1061,157 @@ out:
 }
 
 /*
+ * search the closest allocated block to the left for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the smallest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+int
+ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path,
+                       ext4_lblk_t *logical, ext4_fsblk_t *phys)
+{
+       struct ext4_extent_idx *ix;
+       struct ext4_extent *ex;
+       int depth, ee_len;
+
+       BUG_ON(path == NULL);
+       depth = path->p_depth;
+       *phys = 0;
+
+       if (depth == 0 && path->p_ext == NULL)
+               return 0;
+
+       /* usually extent in the path covers blocks smaller
+        * then *logical, but it can be that extent is the
+        * first one in the file */
+
+       ex = path[depth].p_ext;
+       ee_len = ext4_ext_get_actual_len(ex);
+       if (*logical < le32_to_cpu(ex->ee_block)) {
+               BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
+               while (--depth >= 0) {
+                       ix = path[depth].p_idx;
+                       BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
+               }
+               return 0;
+       }
+
+       BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
+
+       *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
+       *phys = ext_pblock(ex) + ee_len - 1;
+       return 0;
+}
+
+/*
+ * search the closest allocated block to the right for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the smallest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+int
+ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path,
+                       ext4_lblk_t *logical, ext4_fsblk_t *phys)
+{
+       struct buffer_head *bh = NULL;
+       struct ext4_extent_header *eh;
+       struct ext4_extent_idx *ix;
+       struct ext4_extent *ex;
+       ext4_fsblk_t block;
+       int depth, ee_len;
+
+       BUG_ON(path == NULL);
+       depth = path->p_depth;
+       *phys = 0;
+
+       if (depth == 0 && path->p_ext == NULL)
+               return 0;
+
+       /* usually extent in the path covers blocks smaller
+        * then *logical, but it can be that extent is the
+        * first one in the file */
+
+       ex = path[depth].p_ext;
+       ee_len = ext4_ext_get_actual_len(ex);
+       if (*logical < le32_to_cpu(ex->ee_block)) {
+               BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
+               while (--depth >= 0) {
+                       ix = path[depth].p_idx;
+                       BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
+               }
+               *logical = le32_to_cpu(ex->ee_block);
+               *phys = ext_pblock(ex);
+               return 0;
+       }
+
+       BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
+
+       if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
+               /* next allocated block in this leaf */
+               ex++;
+               *logical = le32_to_cpu(ex->ee_block);
+               *phys = ext_pblock(ex);
+               return 0;
+       }
+
+       /* go up and search for index to the right */
+       while (--depth >= 0) {
+               ix = path[depth].p_idx;
+               if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
+                       break;
+       }
+
+       if (depth < 0) {
+               /* we've gone up to the root and
+                * found no index to the right */
+               return 0;
+       }
+
+       /* we've found index to the right, let's
+        * follow it and find the closest allocated
+        * block to the right */
+       ix++;
+       block = idx_pblock(ix);
+       while (++depth < path->p_depth) {
+               bh = sb_bread(inode->i_sb, block);
+               if (bh == NULL)
+                       return -EIO;
+               eh = ext_block_hdr(bh);
+               if (ext4_ext_check_header(inode, eh, depth)) {
+                       put_bh(bh);
+                       return -EIO;
+               }
+               ix = EXT_FIRST_INDEX(eh);
+               block = idx_pblock(ix);
+               put_bh(bh);
+       }
+
+       bh = sb_bread(inode->i_sb, block);
+       if (bh == NULL)
+               return -EIO;
+       eh = ext_block_hdr(bh);
+       if (ext4_ext_check_header(inode, eh, path->p_depth - depth)) {
+               put_bh(bh);
+               return -EIO;
+       }
+       ex = EXT_FIRST_EXTENT(eh);
+       *logical = le32_to_cpu(ex->ee_block);
+       *phys = ext_pblock(ex);
+       put_bh(bh);
+       return 0;
+
+}
+
+/*
  * ext4_ext_next_allocated_block:
  * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
  * NOTE: it considers block number from index entry as
  * allocated block. Thus, index entries have to be consistent
  * with leaves.
  */
-static unsigned long
+static ext4_lblk_t
 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
 {
        int depth;
@@ -1017,8 +1244,8 @@ ext4_ext_next_allocated_block(struct ext4_ext_path *path)
  * ext4_ext_next_leaf_block:
  * returns first allocated block from next leaf or EXT_MAX_BLOCK
  */
-static unsigned ext4_ext_next_leaf_block(struct inode *inode,
-                                               struct ext4_ext_path *path)
+static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
+                                       struct ext4_ext_path *path)
 {
        int depth;
 
@@ -1035,7 +1262,8 @@ static unsigned ext4_ext_next_leaf_block(struct inode *inode,
        while (depth >= 0) {
                if (path[depth].p_idx !=
                                EXT_LAST_INDEX(path[depth].p_hdr))
-                 return le32_to_cpu(path[depth].p_idx[1].ei_block);
+                       return (ext4_lblk_t)
+                               le32_to_cpu(path[depth].p_idx[1].ei_block);
                depth--;
        }
 
@@ -1048,7 +1276,7 @@ static unsigned ext4_ext_next_leaf_block(struct inode *inode,
  * then we have to correct all indexes above.
  * TODO: do we need to correct tree in all cases?
  */
-int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
+static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
                                struct ext4_ext_path *path)
 {
        struct ext4_extent_header *eh;
@@ -1077,32 +1305,53 @@ int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
         */
        k = depth - 1;
        border = path[depth].p_ext->ee_block;
-       if ((err = ext4_ext_get_access(handle, inode, path + k)))
+       err = ext4_ext_get_access(handle, inode, path + k);
+       if (err)
                return err;
        path[k].p_idx->ei_block = border;
-       if ((err = ext4_ext_dirty(handle, inode, path + k)))
+       err = ext4_ext_dirty(handle, inode, path + k);
+       if (err)
                return err;
 
        while (k--) {
                /* change all left-side indexes */
                if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
                        break;
-               if ((err = ext4_ext_get_access(handle, inode, path + k)))
+               err = ext4_ext_get_access(handle, inode, path + k);
+               if (err)
                        break;
                path[k].p_idx->ei_block = border;
-               if ((err = ext4_ext_dirty(handle, inode, path + k)))
+               err = ext4_ext_dirty(handle, inode, path + k);
+               if (err)
                        break;
        }
 
        return err;
 }
 
-static int inline
+static int
 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
                                struct ext4_extent *ex2)
 {
-        if (le32_to_cpu(ex1->ee_block) + le16_to_cpu(ex1->ee_len)
-           != le32_to_cpu(ex2->ee_block))
+       unsigned short ext1_ee_len, ext2_ee_len, max_len;
+
+       /*
+        * Make sure that either both extents are uninitialized, or
+        * both are _not_.
+        */
+       if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
+               return 0;
+
+       if (ext4_ext_is_uninitialized(ex1))
+               max_len = EXT_UNINIT_MAX_LEN;
+       else
+               max_len = EXT_INIT_MAX_LEN;
+
+       ext1_ee_len = ext4_ext_get_actual_len(ex1);
+       ext2_ee_len = ext4_ext_get_actual_len(ex2);
+
+       if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
+                       le32_to_cpu(ex2->ee_block))
                return 0;
 
        /*
@@ -1110,19 +1359,115 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
         * as an RO_COMPAT feature, refuse to merge to extents if
         * this can result in the top bit of ee_len being set.
         */
-       if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN)
+       if (ext1_ee_len + ext2_ee_len > max_len)
                return 0;
-#ifdef AGRESSIVE_TEST
-       if (le16_to_cpu(ex1->ee_len) >= 4)
+#ifdef AGGRESSIVE_TEST
+       if (ext1_ee_len >= 4)
                return 0;
 #endif
 
-        if (ext_pblock(ex1) + le16_to_cpu(ex1->ee_len) == ext_pblock(ex2))
+       if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2))
                return 1;
        return 0;
 }
 
 /*
+ * This function tries to merge the "ex" extent to the next extent in the tree.
+ * It always tries to merge towards right. If you want to merge towards
+ * left, pass "ex - 1" as argument instead of "ex".
+ * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
+ * 1 if they got merged.
+ */
+int ext4_ext_try_to_merge(struct inode *inode,
+                         struct ext4_ext_path *path,
+                         struct ext4_extent *ex)
+{
+       struct ext4_extent_header *eh;
+       unsigned int depth, len;
+       int merge_done = 0;
+       int uninitialized = 0;
+
+       depth = ext_depth(inode);
+       BUG_ON(path[depth].p_hdr == NULL);
+       eh = path[depth].p_hdr;
+
+       while (ex < EXT_LAST_EXTENT(eh)) {
+               if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
+                       break;
+               /* merge with next extent! */
+               if (ext4_ext_is_uninitialized(ex))
+                       uninitialized = 1;
+               ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+                               + ext4_ext_get_actual_len(ex + 1));
+               if (uninitialized)
+                       ext4_ext_mark_uninitialized(ex);
+
+               if (ex + 1 < EXT_LAST_EXTENT(eh)) {
+                       len = (EXT_LAST_EXTENT(eh) - ex - 1)
+                               * sizeof(struct ext4_extent);
+                       memmove(ex + 1, ex + 2, len);
+               }
+               le16_add_cpu(&eh->eh_entries, -1);
+               merge_done = 1;
+               WARN_ON(eh->eh_entries == 0);
+               if (!eh->eh_entries)
+                       ext4_error(inode->i_sb, "ext4_ext_try_to_merge",
+                          "inode#%lu, eh->eh_entries = 0!", inode->i_ino);
+       }
+
+       return merge_done;
+}
+
+/*
+ * check if a portion of the "newext" extent overlaps with an
+ * existing extent.
+ *
+ * If there is an overlap discovered, it updates the length of the newext
+ * such that there will be no overlap, and then returns 1.
+ * If there is no overlap found, it returns 0.
+ */
+unsigned int ext4_ext_check_overlap(struct inode *inode,
+                                   struct ext4_extent *newext,
+                                   struct ext4_ext_path *path)
+{
+       ext4_lblk_t b1, b2;
+       unsigned int depth, len1;
+       unsigned int ret = 0;
+
+       b1 = le32_to_cpu(newext->ee_block);
+       len1 = ext4_ext_get_actual_len(newext);
+       depth = ext_depth(inode);
+       if (!path[depth].p_ext)
+               goto out;
+       b2 = le32_to_cpu(path[depth].p_ext->ee_block);
+
+       /*
+        * get the next allocated block if the extent in the path
+        * is before the requested block(s)
+        */
+       if (b2 < b1) {
+               b2 = ext4_ext_next_allocated_block(path);
+               if (b2 == EXT_MAX_BLOCK)
+                       goto out;
+       }
+
+       /* check for wrap through zero on extent logical start block*/
+       if (b1 + len1 < b1) {
+               len1 = EXT_MAX_BLOCK - b1;
+               newext->ee_len = cpu_to_le16(len1);
+               ret = 1;
+       }
+
+       /* check for overlap */
+       if (b1 + len1 > b2) {
+               newext->ee_len = cpu_to_le16(b2 - b1);
+               ret = 1;
+       }
+out:
+       return ret;
+}
+
+/*
  * ext4_ext_insert_extent:
  * tries to merge requsted extent into the existing extent or
  * inserts requested extent as new one into the tree,
@@ -1132,27 +1477,40 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
                                struct ext4_ext_path *path,
                                struct ext4_extent *newext)
 {
-       struct ext4_extent_header * eh;
+       struct ext4_extent_header *eh;
        struct ext4_extent *ex, *fex;
        struct ext4_extent *nearex; /* nearest extent */
        struct ext4_ext_path *npath = NULL;
-       int depth, len, err, next;
+       int depth, len, err;
+       ext4_lblk_t next;
+       unsigned uninitialized = 0;
 
-       BUG_ON(newext->ee_len == 0);
+       BUG_ON(ext4_ext_get_actual_len(newext) == 0);
        depth = ext_depth(inode);
        ex = path[depth].p_ext;
        BUG_ON(path[depth].p_hdr == NULL);
 
        /* try to insert block into found extent and return */
        if (ex && ext4_can_extents_be_merged(inode, ex, newext)) {
-               ext_debug("append %d block to %d:%d (from "E3FSBLK")\n",
-                               le16_to_cpu(newext->ee_len),
+               ext_debug("append %d block to %d:%d (from %llu)\n",
+                               ext4_ext_get_actual_len(newext),
                                le32_to_cpu(ex->ee_block),
-                               le16_to_cpu(ex->ee_len), ext_pblock(ex));
-               if ((err = ext4_ext_get_access(handle, inode, path + depth)))
+                               ext4_ext_get_actual_len(ex), ext_pblock(ex));
+               err = ext4_ext_get_access(handle, inode, path + depth);
+               if (err)
                        return err;
-               ex->ee_len = cpu_to_le16(le16_to_cpu(ex->ee_len)
-                                        + le16_to_cpu(newext->ee_len));
+
+               /*
+                * ext4_can_extents_be_merged should have checked that either
+                * both extents are uninitialized, or both aren't. Thus we
+                * need to check only one of them here.
+                */
+               if (ext4_ext_is_uninitialized(ex))
+                       uninitialized = 1;
+               ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
+                                       + ext4_ext_get_actual_len(newext));
+               if (uninitialized)
+                       ext4_ext_mark_uninitialized(ex);
                eh = path[depth].p_hdr;
                nearex = ex;
                goto merge;
@@ -1199,28 +1557,29 @@ repeat:
 has_space:
        nearex = path[depth].p_ext;
 
-       if ((err = ext4_ext_get_access(handle, inode, path + depth)))
+       err = ext4_ext_get_access(handle, inode, path + depth);
+       if (err)
                goto cleanup;
 
        if (!nearex) {
                /* there is no extent in this leaf, create first one */
-               ext_debug("first extent in the leaf: %d:"E3FSBLK":%d\n",
-                               le32_to_cpu(newext->ee_block),
-                               ext_pblock(newext),
-                               le16_to_cpu(newext->ee_len));
+               ext_debug("first extent in the leaf: %d:%llu:%d\n",
+                               le32_to_cpu(newext->ee_block),
+                               ext_pblock(newext),
+                               ext4_ext_get_actual_len(newext));
                path[depth].p_ext = EXT_FIRST_EXTENT(eh);
        } else if (le32_to_cpu(newext->ee_block)
-                          > le32_to_cpu(nearex->ee_block)) {
+                          > le32_to_cpu(nearex->ee_block)) {
 /*             BUG_ON(newext->ee_block == nearex->ee_block); */
                if (nearex != EXT_LAST_EXTENT(eh)) {
                        len = EXT_MAX_EXTENT(eh) - nearex;
                        len = (len - 1) * sizeof(struct ext4_extent);
                        len = len < 0 ? 0 : len;
-                       ext_debug("insert %d:"E3FSBLK":%d after: nearest 0x%p, "
+                       ext_debug("insert %d:%llu:%d after: nearest 0x%p, "
                                        "move %d from 0x%p to 0x%p\n",
-                                       le32_to_cpu(newext->ee_block),
-                                       ext_pblock(newext),
-                                       le16_to_cpu(newext->ee_len),
+                                       le32_to_cpu(newext->ee_block),
+                                       ext_pblock(newext),
+                                       ext4_ext_get_actual_len(newext),
                                        nearex, len, nearex + 1, nearex + 2);
                        memmove(nearex + 2, nearex + 1, len);
                }
@@ -1229,39 +1588,25 @@ has_space:
                BUG_ON(newext->ee_block == nearex->ee_block);
                len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent);
                len = len < 0 ? 0 : len;
-               ext_debug("insert %d:"E3FSBLK":%d before: nearest 0x%p, "
+               ext_debug("insert %d:%llu:%d before: nearest 0x%p, "
                                "move %d from 0x%p to 0x%p\n",
                                le32_to_cpu(newext->ee_block),
                                ext_pblock(newext),
-                               le16_to_cpu(newext->ee_len),
+                               ext4_ext_get_actual_len(newext),
                                nearex, len, nearex + 1, nearex + 2);
                memmove(nearex + 1, nearex, len);
                path[depth].p_ext = nearex;
        }
 
-       eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)+1);
+       le16_add_cpu(&eh->eh_entries, 1);
        nearex = path[depth].p_ext;
        nearex->ee_block = newext->ee_block;
-       nearex->ee_start = newext->ee_start;
-       nearex->ee_start_hi = newext->ee_start_hi;
+       ext4_ext_store_pblock(nearex, ext_pblock(newext));
        nearex->ee_len = newext->ee_len;
 
 merge:
        /* try to merge extents to the right */
-       while (nearex < EXT_LAST_EXTENT(eh)) {
-               if (!ext4_can_extents_be_merged(inode, nearex, nearex + 1))
-                       break;
-               /* merge with next extent! */
-               nearex->ee_len = cpu_to_le16(le16_to_cpu(nearex->ee_len)
-                                            + le16_to_cpu(nearex[1].ee_len));
-               if (nearex + 1 < EXT_LAST_EXTENT(eh)) {
-                       len = (EXT_LAST_EXTENT(eh) - nearex - 1)
-                                       * sizeof(struct ext4_extent);
-                       memmove(nearex + 1, nearex + 2, len);
-               }
-               eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1);
-               BUG_ON(eh->eh_entries == 0);
-       }
+       ext4_ext_try_to_merge(inode, path, nearex);
 
        /* try to merge extents to the left */
 
@@ -1282,15 +1627,15 @@ cleanup:
        return err;
 }
 
-int ext4_ext_walk_space(struct inode *inode, unsigned long block,
-                       unsigned long num, ext_prepare_callback func,
+int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
+                       ext4_lblk_t num, ext_prepare_callback func,
                        void *cbdata)
 {
        struct ext4_ext_path *path = NULL;
        struct ext4_ext_cache cbex;
        struct ext4_extent *ex;
-       unsigned long next, start = 0, end = 0;
-       unsigned long last = block + num;
+       ext4_lblk_t next, start = 0, end = 0;
+       ext4_lblk_t last = block + num;
        int depth, exists, err = 0;
 
        BUG_ON(func == NULL);
@@ -1323,8 +1668,8 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
                        end = le32_to_cpu(ex->ee_block);
                        if (block + num < end)
                                end = block + num;
-               } else if (block >=
-                            le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)) {
+               } else if (block >= le32_to_cpu(ex->ee_block)
+                                       + ext4_ext_get_actual_len(ex)) {
                        /* need to allocate space after found extent */
                        start = block;
                        end = block + num;
@@ -1336,7 +1681,8 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
                         * by found extent
                         */
                        start = block;
-                       end = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len);
+                       end = le32_to_cpu(ex->ee_block)
+                               + ext4_ext_get_actual_len(ex);
                        if (block + num < end)
                                end = block + num;
                        exists = 1;
@@ -1351,18 +1697,19 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
                        cbex.ec_start = 0;
                        cbex.ec_type = EXT4_EXT_CACHE_GAP;
                } else {
-                       cbex.ec_block = le32_to_cpu(ex->ee_block);
-                       cbex.ec_len = le16_to_cpu(ex->ee_len);
-                       cbex.ec_start = ext_pblock(ex);
+                       cbex.ec_block = le32_to_cpu(ex->ee_block);
+                       cbex.ec_len = ext4_ext_get_actual_len(ex);
+                       cbex.ec_start = ext_pblock(ex);
                        cbex.ec_type = EXT4_EXT_CACHE_EXTENT;
                }
 
                BUG_ON(cbex.ec_len == 0);
-               err = func(inode, path, &cbex, cbdata);
+               err = func(inode, path, &cbex, ex, cbdata);
                ext4_ext_drop_refs(path);
 
                if (err < 0)
                        break;
+
                if (err == EXT_REPEAT)
                        continue;
                else if (err == EXT_BREAK) {
@@ -1387,9 +1734,9 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
        return err;
 }
 
-static inline void
-ext4_ext_put_in_cache(struct inode *inode, __u32 block,
-                       __u32 len, __u32 start, int type)
+static void
+ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
+                       __u32 len, ext4_fsblk_t start, int type)
 {
        struct ext4_ext_cache *cex;
        BUG_ON(len == 0);
@@ -1405,12 +1752,13 @@ ext4_ext_put_in_cache(struct inode *inode, __u32 block,
  * calculate boundaries of the gap that the requested block fits into
  * and cache this gap
  */
-static inline void
+static void
 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
-                               unsigned long block)
+                               ext4_lblk_t block)
 {
        int depth = ext_depth(inode);
-       unsigned long lblock, len;
+       unsigned long len;
+       ext4_lblk_t lblock;
        struct ext4_extent *ex;
 
        ex = path[depth].p_ext;
@@ -1422,32 +1770,34 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
        } else if (block < le32_to_cpu(ex->ee_block)) {
                lblock = block;
                len = le32_to_cpu(ex->ee_block) - block;
-               ext_debug("cache gap(before): %lu [%lu:%lu]",
-                               (unsigned long) block,
-                               (unsigned long) le32_to_cpu(ex->ee_block),
-                               (unsigned long) le16_to_cpu(ex->ee_len));
+               ext_debug("cache gap(before): %u [%u:%u]",
+                               block,
+                               le32_to_cpu(ex->ee_block),
+                                ext4_ext_get_actual_len(ex));
        } else if (block >= le32_to_cpu(ex->ee_block)
-                           + le16_to_cpu(ex->ee_len)) {
-               lblock = le32_to_cpu(ex->ee_block)
-                        + le16_to_cpu(ex->ee_len);
-               len = ext4_ext_next_allocated_block(path);
-               ext_debug("cache gap(after): [%lu:%lu] %lu",
-                               (unsigned long) le32_to_cpu(ex->ee_block),
-                               (unsigned long) le16_to_cpu(ex->ee_len),
-                               (unsigned long) block);
-               BUG_ON(len == lblock);
-               len = len - lblock;
+                       + ext4_ext_get_actual_len(ex)) {
+               ext4_lblk_t next;
+               lblock = le32_to_cpu(ex->ee_block)
+                       + ext4_ext_get_actual_len(ex);
+
+               next = ext4_ext_next_allocated_block(path);
+               ext_debug("cache gap(after): [%u:%u] %u",
+                               le32_to_cpu(ex->ee_block),
+                               ext4_ext_get_actual_len(ex),
+                               block);
+               BUG_ON(next == lblock);
+               len = next - lblock;
        } else {
                lblock = len = 0;
                BUG();
        }
 
-       ext_debug(" -> %lu:%lu\n", (unsigned long) lblock, len);
+       ext_debug(" -> %u:%lu\n", lblock, len);
        ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP);
 }
 
-static inline int
-ext4_ext_in_cache(struct inode *inode, unsigned long block,
+static int
+ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
                        struct ext4_extent *ex)
 {
        struct ext4_ext_cache *cex;
@@ -1461,14 +1811,12 @@ ext4_ext_in_cache(struct inode *inode, unsigned long block,
        BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP &&
                        cex->ec_type != EXT4_EXT_CACHE_EXTENT);
        if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) {
-               ex->ee_block = cpu_to_le32(cex->ec_block);
+               ex->ee_block = cpu_to_le32(cex->ec_block);
                ext4_ext_store_pblock(ex, cex->ec_start);
-               ex->ee_len = cpu_to_le16(cex->ec_len);
-               ext_debug("%lu cached by %lu:%lu:"E3FSBLK"\n",
-                               (unsigned long) block,
-                               (unsigned long) cex->ec_block,
-                               (unsigned long) cex->ec_len,
-                               cex->ec_start);
+               ex->ee_len = cpu_to_le16(cex->ec_len);
+               ext_debug("%u cached by %u:%u:%llu\n",
+                               block,
+                               cex->ec_block, cex->ec_len, cex->ec_start);
                return cex->ec_type;
        }
 
@@ -1482,7 +1830,7 @@ ext4_ext_in_cache(struct inode *inode, unsigned long block,
  * It's used in truncate case only, thus all requests are for
  * last index in the block only.
  */
-int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
+static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
                        struct ext4_ext_path *path)
 {
        struct buffer_head *bh;
@@ -1493,79 +1841,91 @@ int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
        path--;
        leaf = idx_pblock(path->p_idx);
        BUG_ON(path->p_hdr->eh_entries == 0);
-       if ((err = ext4_ext_get_access(handle, inode, path)))
+       err = ext4_ext_get_access(handle, inode, path);
+       if (err)
                return err;
-       path->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path->p_hdr->eh_entries)-1);
-       if ((err = ext4_ext_dirty(handle, inode, path)))
+       le16_add_cpu(&path->p_hdr->eh_entries, -1);
+       err = ext4_ext_dirty(handle, inode, path);
+       if (err)
                return err;
-       ext_debug("index is empty, remove it, free block "E3FSBLK"\n", leaf);
+       ext_debug("index is empty, remove it, free block %llu\n", leaf);
        bh = sb_find_get_block(inode->i_sb, leaf);
        ext4_forget(handle, 1, inode, bh, leaf);
-       ext4_free_blocks(handle, inode, leaf, 1);
+       ext4_free_blocks(handle, inode, leaf, 1, 1);
        return err;
 }
 
 /*
- * ext4_ext_calc_credits_for_insert:
- * This routine returns max. credits that the extent tree can consume.
- * It should be OK for low-performance paths like ->writepage()
- * To allow many writing processes to fit into a single transaction,
- * the caller should calculate credits under truncate_mutex and
- * pass the actual path.
+ * ext4_ext_calc_credits_for_single_extent:
+ * This routine returns max. credits that needed to insert an extent
+ * to the extent tree.
+ * When pass the actual path, the caller should calculate credits
+ * under i_data_sem.
  */
-int inline ext4_ext_calc_credits_for_insert(struct inode *inode,
+int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
                                                struct ext4_ext_path *path)
 {
-       int depth, needed;
-
        if (path) {
+               int depth = ext_depth(inode);
+               int ret = 0;
+
                /* probably there is space in leaf? */
-               depth = ext_depth(inode);
                if (le16_to_cpu(path[depth].p_hdr->eh_entries)
-                               < le16_to_cpu(path[depth].p_hdr->eh_max))
-                       return 1;
-       }
+                               < le16_to_cpu(path[depth].p_hdr->eh_max)) {
 
-       /*
-        * given 32-bit logical block (4294967296 blocks), max. tree
-        * can be 4 levels in depth -- 4 * 340^4 == 53453440000.
-        * Let's also add one more level for imbalance.
-        */
-       depth = 5;
-
-       /* allocation of new data block(s) */
-       needed = 2;
+                       /*
+                        *  There are some space in the leaf tree, no
+                        *  need to account for leaf block credit
+                        *
+                        *  bitmaps and block group descriptor blocks
+                        *  and other metadat blocks still need to be
+                        *  accounted.
+                        */
+                       /* 1 bitmap, 1 block group descriptor */
+                       ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
+               }
+       }
 
-       /*
-        * tree can be full, so it would need to grow in depth:
-        * allocation + old root + new root
-        */
-       needed += 2 + 1 + 1;
+       return ext4_chunk_trans_blocks(inode, nrblocks);
+}
 
-       /*
-        * Index split can happen, we would need:
-        *    allocate intermediate indexes (bitmap + group)
-        *  + change two blocks at each level, but root (already included)
-        */
-       needed = (depth * 2) + (depth * 2);
+/*
+ * How many index/leaf blocks need to change/allocate to modify nrblocks?
+ *
+ * if nrblocks are fit in a single extent (chunk flag is 1), then
+ * in the worse case, each tree level index/leaf need to be changed
+ * if the tree split due to insert a new extent, then the old tree
+ * index/leaf need to be updated too
+ *
+ * If the nrblocks are discontiguous, they could cause
+ * the whole tree split more than once, but this is really rare.
+ */
+int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+       int index;
+       int depth = ext_depth(inode);
 
-       /* any allocation modifies superblock */
-       needed += 1;
+       if (chunk)
+               index = depth * 2;
+       else
+               index = depth * 3;
 
-       return needed;
+       return index;
 }
 
 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
                                struct ext4_extent *ex,
-                               unsigned long from, unsigned long to)
+                               ext4_lblk_t from, ext4_lblk_t to)
 {
        struct buffer_head *bh;
-       int i;
+       unsigned short ee_len =  ext4_ext_get_actual_len(ex);
+       int i, metadata = 0;
 
+       if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+               metadata = 1;
 #ifdef EXTENTS_STATS
        {
                struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-               unsigned short ee_len =  le16_to_cpu(ex->ee_len);
                spin_lock(&sbi->s_ext_stats_lock);
                sbi->s_ext_blocks += ee_len;
                sbi->s_ext_extents++;
@@ -1579,54 +1939,59 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
        }
 #endif
        if (from >= le32_to_cpu(ex->ee_block)
-           && to == le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) {
+           && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
                /* tail removal */
-               unsigned long num;
+               ext4_lblk_t num;
                ext4_fsblk_t start;
-               num = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - from;
-               start = ext_pblock(ex) + le16_to_cpu(ex->ee_len) - num;
-               ext_debug("free last %lu blocks starting "E3FSBLK"\n", num, start);
+
+               num = le32_to_cpu(ex->ee_block) + ee_len - from;
+               start = ext_pblock(ex) + ee_len - num;
+               ext_debug("free last %u blocks starting %llu\n", num, start);
                for (i = 0; i < num; i++) {
                        bh = sb_find_get_block(inode->i_sb, start + i);
                        ext4_forget(handle, 0, inode, bh, start + i);
                }
-               ext4_free_blocks(handle, inode, start, num);
+               ext4_free_blocks(handle, inode, start, num, metadata);
        } else if (from == le32_to_cpu(ex->ee_block)
-                  && to <= le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) {
-               printk("strange request: removal %lu-%lu from %u:%u\n",
-                      from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len));
+                  && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
+               printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
+                       from, to, le32_to_cpu(ex->ee_block), ee_len);
        } else {
-               printk("strange request: removal(2) %lu-%lu from %u:%u\n",
-                      from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len));
+               printk(KERN_INFO "strange request: removal(2) "
+                               "%u-%u from %u:%u\n",
+                               from, to, le32_to_cpu(ex->ee_block), ee_len);
        }
        return 0;
 }
 
 static int
 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
-               struct ext4_ext_path *path, unsigned long start)
+               struct ext4_ext_path *path, ext4_lblk_t start)
 {
        int err = 0, correct_index = 0;
        int depth = ext_depth(inode), credits;
        struct ext4_extent_header *eh;
-       unsigned a, b, block, num;
-       unsigned long ex_ee_block;
+       ext4_lblk_t a, b, block;
+       unsigned num;
+       ext4_lblk_t ex_ee_block;
        unsigned short ex_ee_len;
+       unsigned uninitialized = 0;
        struct ext4_extent *ex;
 
-       ext_debug("truncate since %lu in leaf\n", start);
+       /* the header must be checked already in ext4_ext_remove_space() */
+       ext_debug("truncate since %u in leaf\n", start);
        if (!path[depth].p_hdr)
                path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
        eh = path[depth].p_hdr;
        BUG_ON(eh == NULL);
-       BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max));
-       BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC);
 
        /* find where to start removing */
        ex = EXT_LAST_EXTENT(eh);
 
        ex_ee_block = le32_to_cpu(ex->ee_block);
-       ex_ee_len = le16_to_cpu(ex->ee_len);
+       if (ext4_ext_is_uninitialized(ex))
+               uninitialized = 1;
+       ex_ee_len = ext4_ext_get_actual_len(ex);
 
        while (ex >= EXT_FIRST_EXTENT(eh) &&
                        ex_ee_block + ex_ee_len > start) {
@@ -1661,22 +2026,22 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
                        BUG_ON(b != ex_ee_block + ex_ee_len - 1);
                }
 
-               /* at present, extent can't cross block group: */
-               /* leaf + bitmap + group desc + sb + inode */
-               credits = 5;
+               /*
+                * 3 for leaf, sb, and inode plus 2 (bmap and group
+                * descriptor) for each block group; assume two block
+                * groups plus ex_ee_len/blocks_per_block_group for
+                * the worst case
+                */
+               credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
                if (ex == EXT_FIRST_EXTENT(eh)) {
                        correct_index = 1;
                        credits += (ext_depth(inode)) + 1;
                }
-#ifdef CONFIG_QUOTA
                credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
 
-               handle = ext4_ext_journal_restart(handle, credits);
-               if (IS_ERR(handle)) {
-                       err = PTR_ERR(handle);
+               err = ext4_ext_journal_restart(handle, credits);
+               if (err)
                        goto out;
-               }
 
                err = ext4_ext_get_access(handle, inode, path + depth);
                if (err)
@@ -1689,21 +2054,27 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
                if (num == 0) {
                        /* this extent is removed; mark slot entirely unused */
                        ext4_ext_store_pblock(ex, 0);
-                       eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1);
+                       le16_add_cpu(&eh->eh_entries, -1);
                }
 
                ex->ee_block = cpu_to_le32(block);
                ex->ee_len = cpu_to_le16(num);
+               /*
+                * Do not mark uninitialized if all the blocks in the
+                * extent have been removed.
+                */
+               if (uninitialized && num)
+                       ext4_ext_mark_uninitialized(ex);
 
                err = ext4_ext_dirty(handle, inode, path + depth);
                if (err)
                        goto out;
 
-               ext_debug("new extent: %u:%u:"E3FSBLK"\n", block, num,
+               ext_debug("new extent: %u:%u:%llu\n", block, num,
                                ext_pblock(ex));
                ex--;
                ex_ee_block = le32_to_cpu(ex->ee_block);
-               ex_ee_len = le16_to_cpu(ex->ee_len);
+               ex_ee_len = ext4_ext_get_actual_len(ex);
        }
 
        if (correct_index && eh->eh_entries)
@@ -1722,7 +2093,7 @@ out:
  * ext4_ext_more_to_rm:
  * returns 1 if current index has to be freed (even partial)
  */
-static int inline
+static int
 ext4_ext_more_to_rm(struct ext4_ext_path *path)
 {
        BUG_ON(path->p_idx == NULL);
@@ -1739,7 +2110,7 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path)
        return 1;
 }
 
-int ext4_ext_remove_space(struct inode *inode, unsigned long start)
+static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
 {
        struct super_block *sb = inode->i_sb;
        int depth = ext_depth(inode);
@@ -1747,7 +2118,7 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)
        handle_t *handle;
        int i = 0, err = 0;
 
-       ext_debug("truncate since %lu\n", start);
+       ext_debug("truncate since %u\n", start);
 
        /* probably first extent we're gonna free will be last in block */
        handle = ext4_journal_start(inode, depth + 1);
@@ -1760,14 +2131,13 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)
         * We start scanning from right side, freeing all the blocks
         * after i_size and walking into the tree depth-wise.
         */
-       path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL);
+       path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS);
        if (path == NULL) {
                ext4_journal_stop(handle);
                return -ENOMEM;
        }
-       memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1));
        path[0].p_hdr = ext_inode_hdr(inode);
-       if (ext4_ext_check_header(__FUNCTION__, inode, path[0].p_hdr)) {
+       if (ext4_ext_check_header(inode, path[0].p_hdr, depth)) {
                err = -EIO;
                goto out;
        }
@@ -1788,17 +2158,8 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)
                if (!path[i].p_hdr) {
                        ext_debug("initialize header\n");
                        path[i].p_hdr = ext_block_hdr(path[i].p_bh);
-                       if (ext4_ext_check_header(__FUNCTION__, inode,
-                                                       path[i].p_hdr)) {
-                               err = -EIO;
-                               goto out;
-                       }
                }
 
-               BUG_ON(le16_to_cpu(path[i].p_hdr->eh_entries)
-                          > le16_to_cpu(path[i].p_hdr->eh_max));
-               BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC);
-
                if (!path[i].p_idx) {
                        /* this level hasn't been touched yet */
                        path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
@@ -1815,17 +2176,27 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)
                                i, EXT_FIRST_INDEX(path[i].p_hdr),
                                path[i].p_idx);
                if (ext4_ext_more_to_rm(path + i)) {
+                       struct buffer_head *bh;
                        /* go to the next level */
-                       ext_debug("move to level %d (block "E3FSBLK")\n",
+                       ext_debug("move to level %d (block %llu)\n",
                                  i + 1, idx_pblock(path[i].p_idx));
                        memset(path + i + 1, 0, sizeof(*path));
-                       path[i+1].p_bh =
-                               sb_bread(sb, idx_pblock(path[i].p_idx));
-                       if (!path[i+1].p_bh) {
+                       bh = sb_bread(sb, idx_pblock(path[i].p_idx));
+                       if (!bh) {
                                /* should we reset i_size? */
                                err = -EIO;
                                break;
                        }
+                       if (WARN_ON(i + 1 > depth)) {
+                               err = -EIO;
+                               break;
+                       }
+                       if (ext4_ext_check_header(inode, ext_block_hdr(bh),
+                                                       depth - i - 1)) {
+                               err = -EIO;
+                               break;
+                       }
+                       path[i + 1].p_bh = bh;
 
                        /* save actual number of indexes since this
                         * number is changed at the next iteration */
@@ -1880,9 +2251,9 @@ void ext4_ext_init(struct super_block *sb)
         */
 
        if (test_opt(sb, EXTENTS)) {
-               printk("EXT4-fs: file extents enabled");
-#ifdef AGRESSIVE_TEST
-               printk(", agressive tests");
+               printk(KERN_INFO "EXT4-fs: file extents enabled");
+#ifdef AGGRESSIVE_TEST
+               printk(", aggressive tests");
 #endif
 #ifdef CHECK_BINSEARCH
                printk(", check binsearch");
@@ -1919,38 +2290,429 @@ void ext4_ext_release(struct super_block *sb)
 #endif
 }
 
+static void bi_complete(struct bio *bio, int error)
+{
+       complete((struct completion *)bio->bi_private);
+}
+
+/* FIXME!! we need to try to merge to left or right after zero-out  */
+static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
+{
+       int ret = -EIO;
+       struct bio *bio;
+       int blkbits, blocksize;
+       sector_t ee_pblock;
+       struct completion event;
+       unsigned int ee_len, len, done, offset;
+
+
+       blkbits   = inode->i_blkbits;
+       blocksize = inode->i_sb->s_blocksize;
+       ee_len    = ext4_ext_get_actual_len(ex);
+       ee_pblock = ext_pblock(ex);
+
+       /* convert ee_pblock to 512 byte sectors */
+       ee_pblock = ee_pblock << (blkbits - 9);
+
+       while (ee_len > 0) {
+
+               if (ee_len > BIO_MAX_PAGES)
+                       len = BIO_MAX_PAGES;
+               else
+                       len = ee_len;
+
+               bio = bio_alloc(GFP_NOIO, len);
+               if (!bio)
+                       return -ENOMEM;
+               bio->bi_sector = ee_pblock;
+               bio->bi_bdev   = inode->i_sb->s_bdev;
+
+               done = 0;
+               offset = 0;
+               while (done < len) {
+                       ret = bio_add_page(bio, ZERO_PAGE(0),
+                                                       blocksize, offset);
+                       if (ret != blocksize) {
+                               /*
+                                * We can't add any more pages because of
+                                * hardware limitations.  Start a new bio.
+                                */
+                               break;
+                       }
+                       done++;
+                       offset += blocksize;
+                       if (offset >= PAGE_CACHE_SIZE)
+                               offset = 0;
+               }
+
+               init_completion(&event);
+               bio->bi_private = &event;
+               bio->bi_end_io = bi_complete;
+               submit_bio(WRITE, bio);
+               wait_for_completion(&event);
+
+               if (test_bit(BIO_UPTODATE, &bio->bi_flags))
+                       ret = 0;
+               else {
+                       ret = -EIO;
+                       break;
+               }
+               bio_put(bio);
+               ee_len    -= done;
+               ee_pblock += done  << (blkbits - 9);
+       }
+       return ret;
+}
+
+#define EXT4_EXT_ZERO_LEN 7
+
+/*
+ * This function is called by ext4_ext_get_blocks() if someone tries to write
+ * to an uninitialized extent. It may result in splitting the uninitialized
+ * extent into multiple extents (upto three - one initialized and two
+ * uninitialized).
+ * There are three possibilities:
+ *   a> There is no split required: Entire extent should be initialized
+ *   b> Splits in two extents: Write is happening at either end of the extent
+ *   c> Splits in three extents: Somone is writing in middle of the extent
+ */
+static int ext4_ext_convert_to_initialized(handle_t *handle,
+                                               struct inode *inode,
+                                               struct ext4_ext_path *path,
+                                               ext4_lblk_t iblock,
+                                               unsigned long max_blocks)
+{
+       struct ext4_extent *ex, newex, orig_ex;
+       struct ext4_extent *ex1 = NULL;
+       struct ext4_extent *ex2 = NULL;
+       struct ext4_extent *ex3 = NULL;
+       struct ext4_extent_header *eh;
+       ext4_lblk_t ee_block;
+       unsigned int allocated, ee_len, depth;
+       ext4_fsblk_t newblock;
+       int err = 0;
+       int ret = 0;
+
+       depth = ext_depth(inode);
+       eh = path[depth].p_hdr;
+       ex = path[depth].p_ext;
+       ee_block = le32_to_cpu(ex->ee_block);
+       ee_len = ext4_ext_get_actual_len(ex);
+       allocated = ee_len - (iblock - ee_block);
+       newblock = iblock - ee_block + ext_pblock(ex);
+       ex2 = ex;
+       orig_ex.ee_block = ex->ee_block;
+       orig_ex.ee_len   = cpu_to_le16(ee_len);
+       ext4_ext_store_pblock(&orig_ex, ext_pblock(ex));
+
+       err = ext4_ext_get_access(handle, inode, path + depth);
+       if (err)
+               goto out;
+       /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
+       if (ee_len <= 2*EXT4_EXT_ZERO_LEN) {
+               err =  ext4_ext_zeroout(inode, &orig_ex);
+               if (err)
+                       goto fix_extent_len;
+               /* update the extent length and mark as initialized */
+               ex->ee_block = orig_ex.ee_block;
+               ex->ee_len   = orig_ex.ee_len;
+               ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+               ext4_ext_dirty(handle, inode, path + depth);
+               /* zeroed the full extent */
+               return allocated;
+       }
+
+       /* ex1: ee_block to iblock - 1 : uninitialized */
+       if (iblock > ee_block) {
+               ex1 = ex;
+               ex1->ee_len = cpu_to_le16(iblock - ee_block);
+               ext4_ext_mark_uninitialized(ex1);
+               ex2 = &newex;
+       }
+       /*
+        * for sanity, update the length of the ex2 extent before
+        * we insert ex3, if ex1 is NULL. This is to avoid temporary
+        * overlap of blocks.
+        */
+       if (!ex1 && allocated > max_blocks)
+               ex2->ee_len = cpu_to_le16(max_blocks);
+       /* ex3: to ee_block + ee_len : uninitialised */
+       if (allocated > max_blocks) {
+               unsigned int newdepth;
+               /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
+               if (allocated <= EXT4_EXT_ZERO_LEN) {
+                       /*
+                        * iblock == ee_block is handled by the zerouout
+                        * at the beginning.
+                        * Mark first half uninitialized.
+                        * Mark second half initialized and zero out the
+                        * initialized extent
+                        */
+                       ex->ee_block = orig_ex.ee_block;
+                       ex->ee_len   = cpu_to_le16(ee_len - allocated);
+                       ext4_ext_mark_uninitialized(ex);
+                       ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+                       ext4_ext_dirty(handle, inode, path + depth);
+
+                       ex3 = &newex;
+                       ex3->ee_block = cpu_to_le32(iblock);
+                       ext4_ext_store_pblock(ex3, newblock);
+                       ex3->ee_len = cpu_to_le16(allocated);
+                       err = ext4_ext_insert_extent(handle, inode, path, ex3);
+                       if (err == -ENOSPC) {
+                               err =  ext4_ext_zeroout(inode, &orig_ex);
+                               if (err)
+                                       goto fix_extent_len;
+                               ex->ee_block = orig_ex.ee_block;
+                               ex->ee_len   = orig_ex.ee_len;
+                               ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+                               ext4_ext_dirty(handle, inode, path + depth);
+                               /* blocks available from iblock */
+                               return allocated;
+
+                       } else if (err)
+                               goto fix_extent_len;
+
+                       /*
+                        * We need to zero out the second half because
+                        * an fallocate request can update file size and
+                        * converting the second half to initialized extent
+                        * implies that we can leak some junk data to user
+                        * space.
+                        */
+                       err =  ext4_ext_zeroout(inode, ex3);
+                       if (err) {
+                               /*
+                                * We should actually mark the
+                                * second half as uninit and return error
+                                * Insert would have changed the extent
+                                */
+                               depth = ext_depth(inode);
+                               ext4_ext_drop_refs(path);
+                               path = ext4_ext_find_extent(inode,
+                                                               iblock, path);
+                               if (IS_ERR(path)) {
+                                       err = PTR_ERR(path);
+                                       return err;
+                               }
+                               /* get the second half extent details */
+                               ex = path[depth].p_ext;
+                               err = ext4_ext_get_access(handle, inode,
+                                                               path + depth);
+                               if (err)
+                                       return err;
+                               ext4_ext_mark_uninitialized(ex);
+                               ext4_ext_dirty(handle, inode, path + depth);
+                               return err;
+                       }
+
+                       /* zeroed the second half */
+                       return allocated;
+               }
+               ex3 = &newex;
+               ex3->ee_block = cpu_to_le32(iblock + max_blocks);
+               ext4_ext_store_pblock(ex3, newblock + max_blocks);
+               ex3->ee_len = cpu_to_le16(allocated - max_blocks);
+               ext4_ext_mark_uninitialized(ex3);
+               err = ext4_ext_insert_extent(handle, inode, path, ex3);
+               if (err == -ENOSPC) {
+                       err =  ext4_ext_zeroout(inode, &orig_ex);
+                       if (err)
+                               goto fix_extent_len;
+                       /* update the extent length and mark as initialized */
+                       ex->ee_block = orig_ex.ee_block;
+                       ex->ee_len   = orig_ex.ee_len;
+                       ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+                       ext4_ext_dirty(handle, inode, path + depth);
+                       /* zeroed the full extent */
+                       /* blocks available from iblock */
+                       return allocated;
+
+               } else if (err)
+                       goto fix_extent_len;
+               /*
+                * The depth, and hence eh & ex might change
+                * as part of the insert above.
+                */
+               newdepth = ext_depth(inode);
+               /*
+                * update the extent length after successfull insert of the
+                * split extent
+                */
+               orig_ex.ee_len = cpu_to_le16(ee_len -
+                                               ext4_ext_get_actual_len(ex3));
+               depth = newdepth;
+               ext4_ext_drop_refs(path);
+               path = ext4_ext_find_extent(inode, iblock, path);
+               if (IS_ERR(path)) {
+                       err = PTR_ERR(path);
+                       goto out;
+               }
+               eh = path[depth].p_hdr;
+               ex = path[depth].p_ext;
+               if (ex2 != &newex)
+                       ex2 = ex;
+
+               err = ext4_ext_get_access(handle, inode, path + depth);
+               if (err)
+                       goto out;
+
+               allocated = max_blocks;
+
+               /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
+                * to insert a extent in the middle zerout directly
+                * otherwise give the extent a chance to merge to left
+                */
+               if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN &&
+                                                       iblock != ee_block) {
+                       err =  ext4_ext_zeroout(inode, &orig_ex);
+                       if (err)
+                               goto fix_extent_len;
+                       /* update the extent length and mark as initialized */
+                       ex->ee_block = orig_ex.ee_block;
+                       ex->ee_len   = orig_ex.ee_len;
+                       ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+                       ext4_ext_dirty(handle, inode, path + depth);
+                       /* zero out the first half */
+                       /* blocks available from iblock */
+                       return allocated;
+               }
+       }
+       /*
+        * If there was a change of depth as part of the
+        * insertion of ex3 above, we need to update the length
+        * of the ex1 extent again here
+        */
+       if (ex1 && ex1 != ex) {
+               ex1 = ex;
+               ex1->ee_len = cpu_to_le16(iblock - ee_block);
+               ext4_ext_mark_uninitialized(ex1);
+               ex2 = &newex;
+       }
+       /* ex2: iblock to iblock + maxblocks-1 : initialised */
+       ex2->ee_block = cpu_to_le32(iblock);
+       ext4_ext_store_pblock(ex2, newblock);
+       ex2->ee_len = cpu_to_le16(allocated);
+       if (ex2 != ex)
+               goto insert;
+       /*
+        * New (initialized) extent starts from the first block
+        * in the current extent. i.e., ex2 == ex
+        * We have to see if it can be merged with the extent
+        * on the left.
+        */
+       if (ex2 > EXT_FIRST_EXTENT(eh)) {
+               /*
+                * To merge left, pass "ex2 - 1" to try_to_merge(),
+                * since it merges towards right _only_.
+                */
+               ret = ext4_ext_try_to_merge(inode, path, ex2 - 1);
+               if (ret) {
+                       err = ext4_ext_correct_indexes(handle, inode, path);
+                       if (err)
+                               goto out;
+                       depth = ext_depth(inode);
+                       ex2--;
+               }
+       }
+       /*
+        * Try to Merge towards right. This might be required
+        * only when the whole extent is being written to.
+        * i.e. ex2 == ex and ex3 == NULL.
+        */
+       if (!ex3) {
+               ret = ext4_ext_try_to_merge(inode, path, ex2);
+               if (ret) {
+                       err = ext4_ext_correct_indexes(handle, inode, path);
+                       if (err)
+                               goto out;
+               }
+       }
+       /* Mark modified extent as dirty */
+       err = ext4_ext_dirty(handle, inode, path + depth);
+       goto out;
+insert:
+       err = ext4_ext_insert_extent(handle, inode, path, &newex);
+       if (err == -ENOSPC) {
+               err =  ext4_ext_zeroout(inode, &orig_ex);
+               if (err)
+                       goto fix_extent_len;
+               /* update the extent length and mark as initialized */
+               ex->ee_block = orig_ex.ee_block;
+               ex->ee_len   = orig_ex.ee_len;
+               ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+               ext4_ext_dirty(handle, inode, path + depth);
+               /* zero out the first half */
+               return allocated;
+       } else if (err)
+               goto fix_extent_len;
+out:
+       return err ? err : allocated;
+
+fix_extent_len:
+       ex->ee_block = orig_ex.ee_block;
+       ex->ee_len   = orig_ex.ee_len;
+       ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
+       ext4_ext_mark_uninitialized(ex);
+       ext4_ext_dirty(handle, inode, path + depth);
+       return err;
+}
+
+/*
+ * Block allocation/map/preallocation routine for extents based files
+ *
+ *
+ * Need to be called with
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
+ * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
+ *
+ * return > 0, number of of blocks already mapped/allocated
+ *          if create == 0 and these are pre-allocated blocks
+ *             buffer head is unmapped
+ *          otherwise blocks are mapped
+ *
+ * return = 0, if plain look up failed (blocks have not been allocated)
+ *          buffer head is unmapped
+ *
+ * return < 0, error case.
+ */
 int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
-                       ext4_fsblk_t iblock,
+                       ext4_lblk_t iblock,
                        unsigned long max_blocks, struct buffer_head *bh_result,
                        int create, int extend_disksize)
 {
        struct ext4_ext_path *path = NULL;
+       struct ext4_extent_header *eh;
        struct ext4_extent newex, *ex;
        ext4_fsblk_t goal, newblock;
-       int err = 0, depth;
+       int err = 0, depth, ret;
        unsigned long allocated = 0;
+       struct ext4_allocation_request ar;
+       loff_t disksize;
 
        __clear_bit(BH_New, &bh_result->b_state);
-       ext_debug("blocks %d/%lu requested for inode %u\n", (int) iblock,
-                       max_blocks, (unsigned) inode->i_ino);
-       mutex_lock(&EXT4_I(inode)->truncate_mutex);
+       ext_debug("blocks %u/%lu requested for inode %u\n",
+                       iblock, max_blocks, inode->i_ino);
 
        /* check in cache */
-       if ((goal = ext4_ext_in_cache(inode, iblock, &newex))) {
+       goal = ext4_ext_in_cache(inode, iblock, &newex);
+       if (goal) {
                if (goal == EXT4_EXT_CACHE_GAP) {
                        if (!create) {
-                               /* block isn't allocated yet and
-                                * user doesn't want to allocate it */
+                               /*
+                                * block isn't allocated yet and
+                                * user doesn't want to allocate it
+                                */
                                goto out2;
                        }
                        /* we should allocate requested block */
                } else if (goal == EXT4_EXT_CACHE_EXTENT) {
                        /* block is already allocated */
-                       newblock = iblock
-                                  - le32_to_cpu(newex.ee_block)
-                                  + ext_pblock(&newex);
+                       newblock = iblock
+                                  - le32_to_cpu(newex.ee_block)
+                                  + ext_pblock(&newex);
                        /* number of remaining blocks in the extent */
-                       allocated = le16_to_cpu(newex.ee_len) -
+                       allocated = ext4_ext_get_actual_len(&newex) -
                                        (iblock - le32_to_cpu(newex.ee_block));
                        goto out;
                } else {
@@ -1974,30 +2736,59 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
         * this is why assert can't be put in ext4_ext_find_extent()
         */
        BUG_ON(path[depth].p_ext == NULL && depth != 0);
+       eh = path[depth].p_hdr;
 
-       if ((ex = path[depth].p_ext)) {
-               unsigned long ee_block = le32_to_cpu(ex->ee_block);
+       ex = path[depth].p_ext;
+       if (ex) {
+               ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
                ext4_fsblk_t ee_start = ext_pblock(ex);
-               unsigned short ee_len  = le16_to_cpu(ex->ee_len);
+               unsigned short ee_len;
 
                /*
-                * Allow future support for preallocated extents to be added
-                * as an RO_COMPAT feature:
                 * Uninitialized extents are treated as holes, except that
-                * we avoid (fail) allocating new blocks during a write.
+                * we split out initialized portions during a write.
                 */
-               if (ee_len > EXT_MAX_LEN)
-                       goto out2;
+               ee_len = ext4_ext_get_actual_len(ex);
                /* if found extent covers block, simply return it */
-               if (iblock >= ee_block && iblock < ee_block + ee_len) {
+               if (iblock >= ee_block && iblock < ee_block + ee_len) {
                        newblock = iblock - ee_block + ee_start;
                        /* number of remaining blocks in the extent */
                        allocated = ee_len - (iblock - ee_block);
-                       ext_debug("%d fit into %lu:%d -> "E3FSBLK"\n", (int) iblock,
+                       ext_debug("%u fit into %lu:%d -> %llu\n", iblock,
                                        ee_block, ee_len, newblock);
-                       ext4_ext_put_in_cache(inode, ee_block, ee_len,
-                                               ee_start, EXT4_EXT_CACHE_EXTENT);
-                       goto out;
+
+                       /* Do not put uninitialized extent in the cache */
+                       if (!ext4_ext_is_uninitialized(ex)) {
+                               ext4_ext_put_in_cache(inode, ee_block,
+                                                       ee_len, ee_start,
+                                                       EXT4_EXT_CACHE_EXTENT);
+                               goto out;
+                       }
+                       if (create == EXT4_CREATE_UNINITIALIZED_EXT)
+                               goto out;
+                       if (!create) {
+                               /*
+                                * We have blocks reserved already.  We
+                                * return allocated blocks so that delalloc
+                                * won't do block reservation for us.  But
+                                * the buffer head will be unmapped so that
+                                * a read from the block returns 0s.
+                                */
+                               if (allocated > max_blocks)
+                                       allocated = max_blocks;
+                               set_buffer_unwritten(bh_result);
+                               goto out2;
+                       }
+
+                       ret = ext4_ext_convert_to_initialized(handle, inode,
+                                                               path, iblock,
+                                                               max_blocks);
+                       if (ret <= 0) {
+                               err = ret;
+                               goto out2;
+                       } else
+                               allocated = ret;
+                       goto outnew;
                }
        }
 
@@ -2006,49 +2797,104 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
         * we couldn't try to create block if create flag is zero
         */
        if (!create) {
-               /* put just found gap into cache to speed up
-                * subsequent requests */
+               /*
+                * put just found gap into cache to speed up
+                * subsequent requests
+                */
                ext4_ext_put_gap_in_cache(inode, path, iblock);
                goto out2;
        }
        /*
-         * Okay, we need to do block allocation.  Lazily initialize the block
-         * allocation info here if necessary.
-        */
-       if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info))
-               ext4_init_block_alloc_info(inode);
+        * Okay, we need to do block allocation.
+        */
+
+       /* find neighbour allocated blocks */
+       ar.lleft = iblock;
+       err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
+       if (err)
+               goto out2;
+       ar.lright = iblock;
+       err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
+       if (err)
+               goto out2;
+
+       /*
+        * See if request is beyond maximum number of blocks we can have in
+        * a single extent. For an initialized extent this limit is
+        * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
+        * EXT_UNINIT_MAX_LEN.
+        */
+       if (max_blocks > EXT_INIT_MAX_LEN &&
+           create != EXT4_CREATE_UNINITIALIZED_EXT)
+               max_blocks = EXT_INIT_MAX_LEN;
+       else if (max_blocks > EXT_UNINIT_MAX_LEN &&
+                create == EXT4_CREATE_UNINITIALIZED_EXT)
+               max_blocks = EXT_UNINIT_MAX_LEN;
+
+       /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
+       newex.ee_block = cpu_to_le32(iblock);
+       newex.ee_len = cpu_to_le16(max_blocks);
+       err = ext4_ext_check_overlap(inode, &newex, path);
+       if (err)
+               allocated = ext4_ext_get_actual_len(&newex);
+       else
+               allocated = max_blocks;
 
        /* allocate new block */
-       goal = ext4_ext_find_goal(inode, path, iblock);
-       allocated = max_blocks;
-       newblock = ext4_new_blocks(handle, inode, goal, &allocated, &err);
+       ar.inode = inode;
+       ar.goal = ext4_ext_find_goal(inode, path, iblock);
+       ar.logical = iblock;
+       ar.len = allocated;
+       if (S_ISREG(inode->i_mode))
+               ar.flags = EXT4_MB_HINT_DATA;
+       else
+               /* disable in-core preallocation for non-regular files */
+               ar.flags = 0;
+       newblock = ext4_mb_new_blocks(handle, &ar, &err);
        if (!newblock)
                goto out2;
-       ext_debug("allocate new block: goal "E3FSBLK", found "E3FSBLK"/%lu\n",
+       ext_debug("allocate new block: goal %llu, found %llu/%lu\n",
                        goal, newblock, allocated);
 
        /* try to insert new extent into found leaf and return */
-       newex.ee_block = cpu_to_le32(iblock);
        ext4_ext_store_pblock(&newex, newblock);
-       newex.ee_len = cpu_to_le16(allocated);
+       newex.ee_len = cpu_to_le16(ar.len);
+       if (create == EXT4_CREATE_UNINITIALIZED_EXT)  /* Mark uninitialized */
+               ext4_ext_mark_uninitialized(&newex);
        err = ext4_ext_insert_extent(handle, inode, path, &newex);
-       if (err)
+       if (err) {
+               /* free data blocks we just allocated */
+               /* not a good idea to call discard here directly,
+                * but otherwise we'd need to call it every free() */
+               ext4_discard_preallocations(inode);
+               ext4_free_blocks(handle, inode, ext_pblock(&newex),
+                                       ext4_ext_get_actual_len(&newex), 0);
                goto out2;
-
-       if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize)
-               EXT4_I(inode)->i_disksize = inode->i_size;
+       }
 
        /* previous routine could use block we allocated */
        newblock = ext_pblock(&newex);
-       __set_bit(BH_New, &bh_result->b_state);
+       allocated = ext4_ext_get_actual_len(&newex);
+outnew:
+       if (extend_disksize) {
+               disksize = ((loff_t) iblock + ar.len) << inode->i_blkbits;
+               if (disksize > i_size_read(inode))
+                       disksize = i_size_read(inode);
+               if (disksize > EXT4_I(inode)->i_disksize)
+                       EXT4_I(inode)->i_disksize = disksize;
+       }
+
+       set_buffer_new(bh_result);
 
-       ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
-                               EXT4_EXT_CACHE_EXTENT);
+       /* Cache only when it is _not_ an uninitialized extent */
+       if (create != EXT4_CREATE_UNINITIALIZED_EXT)
+               ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
+                                               EXT4_EXT_CACHE_EXTENT);
 out:
        if (allocated > max_blocks)
                allocated = max_blocks;
        ext4_ext_show_leaf(inode, path);
-       __set_bit(BH_Mapped, &bh_result->b_state);
+       set_buffer_mapped(bh_result);
        bh_result->b_bdev = inode->i_sb->s_bdev;
        bh_result->b_blocknr = newblock;
 out2:
@@ -2056,47 +2902,41 @@ out2:
                ext4_ext_drop_refs(path);
                kfree(path);
        }
-       mutex_unlock(&EXT4_I(inode)->truncate_mutex);
-
        return err ? err : allocated;
 }
 
-void ext4_ext_truncate(struct inode * inode, struct page *page)
+void ext4_ext_truncate(struct inode *inode)
 {
        struct address_space *mapping = inode->i_mapping;
        struct super_block *sb = inode->i_sb;
-       unsigned long last_block;
+       ext4_lblk_t last_block;
        handle_t *handle;
        int err = 0;
 
        /*
         * probably first extent we're gonna free will be last in block
         */
-       err = ext4_writepage_trans_blocks(inode) + 3;
+       err = ext4_writepage_trans_blocks(inode);
        handle = ext4_journal_start(inode, err);
-       if (IS_ERR(handle)) {
-               if (page) {
-                       clear_highpage(page);
-                       flush_dcache_page(page);
-                       unlock_page(page);
-                       page_cache_release(page);
-               }
+       if (IS_ERR(handle))
                return;
-       }
 
-       if (page)
-               ext4_block_truncate_page(handle, page, mapping, inode->i_size);
+       if (inode->i_size & (sb->s_blocksize - 1))
+               ext4_block_truncate_page(handle, mapping, inode->i_size);
+
+       if (ext4_orphan_add(handle, inode))
+               goto out_stop;
 
-       mutex_lock(&EXT4_I(inode)->truncate_mutex);
+       down_write(&EXT4_I(inode)->i_data_sem);
        ext4_ext_invalidate_cache(inode);
 
+       ext4_discard_preallocations(inode);
+
        /*
         * TODO: optimization is possible here.
         * Probably we need not scan at all,
         * because page truncation is enough.
         */
-       if (ext4_orphan_add(handle, inode))
-               goto out_stop;
 
        /* we have to know where to truncate from in crash case */
        EXT4_I(inode)->i_disksize = inode->i_size;
@@ -2107,11 +2947,13 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
        err = ext4_ext_remove_space(inode, last_block);
 
        /* In a multi-transaction truncate, we only make the final
-        * transaction synchronous. */
+        * transaction synchronous.
+        */
        if (IS_SYNC(inode))
                handle->h_sync = 1;
 
 out_stop:
+       up_write(&EXT4_I(inode)->i_data_sem);
        /*
         * If this was a simple ftruncate() and the file will remain alive,
         * then we need to clear up the orphan record which we created above.
@@ -2122,35 +2964,258 @@ out_stop:
        if (inode->i_nlink)
                ext4_orphan_del(handle, inode);
 
-       mutex_unlock(&EXT4_I(inode)->truncate_mutex);
+       inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+       ext4_mark_inode_dirty(handle, inode);
        ext4_journal_stop(handle);
 }
 
+static void ext4_falloc_update_inode(struct inode *inode,
+                               int mode, loff_t new_size, int update_ctime)
+{
+       struct timespec now;
+
+       if (update_ctime) {
+               now = current_fs_time(inode->i_sb);
+               if (!timespec_equal(&inode->i_ctime, &now))
+                       inode->i_ctime = now;
+       }
+       /*
+        * Update only when preallocation was requested beyond
+        * the file size.
+        */
+       if (!(mode & FALLOC_FL_KEEP_SIZE)) {
+               if (new_size > i_size_read(inode))
+                       i_size_write(inode, new_size);
+               if (new_size > EXT4_I(inode)->i_disksize)
+                       ext4_update_i_disksize(inode, new_size);
+       }
+
+}
+
 /*
- * ext4_ext_writepage_trans_blocks:
- * calculate max number of blocks we could modify
- * in order to allocate new block for an inode
+ * preallocate space for a file. This implements ext4's fallocate inode
+ * operation, which gets called from sys_fallocate system call.
+ * For block-mapped files, posix_fallocate should fall back to the method
+ * of writing zeroes to the required new blocks (the same behavior which is
+ * expected for file systems which do not support fallocate() system call).
  */
-int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
+long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
 {
-       int needed;
+       handle_t *handle;
+       ext4_lblk_t block;
+       loff_t new_size;
+       unsigned long max_blocks;
+       int ret = 0;
+       int ret2 = 0;
+       int retries = 0;
+       struct buffer_head map_bh;
+       unsigned int credits, blkbits = inode->i_blkbits;
 
-       needed = ext4_ext_calc_credits_for_insert(inode, NULL);
+       /*
+        * currently supporting (pre)allocate mode for extent-based
+        * files _only_
+        */
+       if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+               return -EOPNOTSUPP;
 
-       /* caller wants to allocate num blocks, but note it includes sb */
-       needed = needed * num - (num - 1);
+       /* preallocation to directories is currently not supported */
+       if (S_ISDIR(inode->i_mode))
+               return -ENODEV;
 
-#ifdef CONFIG_QUOTA
-       needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
+       block = offset >> blkbits;
+       /*
+        * We can't just convert len to max_blocks because
+        * If blocksize = 4096 offset = 3072 and len = 2048
+        */
+       max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
+                                                       - block;
+       /*
+        * credits to insert 1 extent into extent tree
+        */
+       credits = ext4_chunk_trans_blocks(inode, max_blocks);
+       mutex_lock(&inode->i_mutex);
+retry:
+       while (ret >= 0 && ret < max_blocks) {
+               block = block + ret;
+               max_blocks = max_blocks - ret;
+               handle = ext4_journal_start(inode, credits);
+               if (IS_ERR(handle)) {
+                       ret = PTR_ERR(handle);
+                       break;
+               }
+               ret = ext4_get_blocks_wrap(handle, inode, block,
+                                         max_blocks, &map_bh,
+                                         EXT4_CREATE_UNINITIALIZED_EXT, 0, 0);
+               if (ret <= 0) {
+#ifdef EXT4FS_DEBUG
+                       WARN_ON(ret <= 0);
+                       printk(KERN_ERR "%s: ext4_ext_get_blocks "
+                                   "returned error inode#%lu, block=%u, "
+                                   "max_blocks=%lu", __func__,
+                                   inode->i_ino, block, max_blocks);
 #endif
+                       ext4_mark_inode_dirty(handle, inode);
+                       ret2 = ext4_journal_stop(handle);
+                       break;
+               }
+               if ((block + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
+                                               blkbits) >> blkbits))
+                       new_size = offset + len;
+               else
+                       new_size = (block + ret) << blkbits;
+
+               ext4_falloc_update_inode(inode, mode, new_size,
+                                               buffer_new(&map_bh));
+               ext4_mark_inode_dirty(handle, inode);
+               ret2 = ext4_journal_stop(handle);
+               if (ret2)
+                       break;
+       }
+       if (ret == -ENOSPC &&
+                       ext4_should_retry_alloc(inode->i_sb, &retries)) {
+               ret = 0;
+               goto retry;
+       }
+       mutex_unlock(&inode->i_mutex);
+       return ret > 0 ? ret2 : ret;
+}
+
+/*
+ * Callback function called for each extent to gather FIEMAP information.
+ */
+int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path,
+                      struct ext4_ext_cache *newex, struct ext4_extent *ex,
+                      void *data)
+{
+       struct fiemap_extent_info *fieinfo = data;
+       unsigned long blksize_bits = inode->i_sb->s_blocksize_bits;
+       __u64   logical;
+       __u64   physical;
+       __u64   length;
+       __u32   flags = 0;
+       int     error;
+
+       logical =  (__u64)newex->ec_block << blksize_bits;
+
+       if (newex->ec_type == EXT4_EXT_CACHE_GAP) {
+               pgoff_t offset;
+               struct page *page;
+               struct buffer_head *bh = NULL;
 
-       return needed;
+               offset = logical >> PAGE_SHIFT;
+               page = find_get_page(inode->i_mapping, offset);
+               if (!page || !page_has_buffers(page))
+                       return EXT_CONTINUE;
+
+               bh = page_buffers(page);
+
+               if (!bh)
+                       return EXT_CONTINUE;
+
+               if (buffer_delay(bh)) {
+                       flags |= FIEMAP_EXTENT_DELALLOC;
+                       page_cache_release(page);
+               } else {
+                       page_cache_release(page);
+                       return EXT_CONTINUE;
+               }
+       }
+
+       physical = (__u64)newex->ec_start << blksize_bits;
+       length =   (__u64)newex->ec_len << blksize_bits;
+
+       if (ex && ext4_ext_is_uninitialized(ex))
+               flags |= FIEMAP_EXTENT_UNWRITTEN;
+
+       /*
+        * If this extent reaches EXT_MAX_BLOCK, it must be last.
+        *
+        * Or if ext4_ext_next_allocated_block is EXT_MAX_BLOCK,
+        * this also indicates no more allocated blocks.
+        *
+        * XXX this might miss a single-block extent at EXT_MAX_BLOCK
+        */
+       if (logical + length - 1 == EXT_MAX_BLOCK ||
+           ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK)
+               flags |= FIEMAP_EXTENT_LAST;
+
+       error = fiemap_fill_next_extent(fieinfo, logical, physical,
+                                       length, flags);
+       if (error < 0)
+               return error;
+       if (error == 1)
+               return EXT_BREAK;
+
+       return EXT_CONTINUE;
 }
 
-EXPORT_SYMBOL(ext4_mark_inode_dirty);
-EXPORT_SYMBOL(ext4_ext_invalidate_cache);
-EXPORT_SYMBOL(ext4_ext_insert_extent);
-EXPORT_SYMBOL(ext4_ext_walk_space);
-EXPORT_SYMBOL(ext4_ext_find_goal);
-EXPORT_SYMBOL(ext4_ext_calc_credits_for_insert);
+/* fiemap flags we can handle specified here */
+#define EXT4_FIEMAP_FLAGS      (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
+
+int ext4_xattr_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
+{
+       __u64 physical = 0;
+       __u64 length;
+       __u32 flags = FIEMAP_EXTENT_LAST;
+       int blockbits = inode->i_sb->s_blocksize_bits;
+       int error = 0;
+
+       /* in-inode? */
+       if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
+               struct ext4_iloc iloc;
+               int offset;     /* offset of xattr in inode */
+
+               error = ext4_get_inode_loc(inode, &iloc);
+               if (error)
+                       return error;
+               physical = iloc.bh->b_blocknr << blockbits;
+               offset = EXT4_GOOD_OLD_INODE_SIZE +
+                               EXT4_I(inode)->i_extra_isize;
+               physical += offset;
+               length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
+               flags |= FIEMAP_EXTENT_DATA_INLINE;
+       } else { /* external block */
+               physical = EXT4_I(inode)->i_file_acl << blockbits;
+               length = inode->i_sb->s_blocksize;
+       }
+
+       if (physical)
+               error = fiemap_fill_next_extent(fieinfo, 0, physical,
+                                               length, flags);
+       return (error < 0 ? error : 0);
+}
+
+int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+               __u64 start, __u64 len)
+{
+       ext4_lblk_t start_blk;
+       ext4_lblk_t len_blks;
+       int error = 0;
+
+       /* fallback to generic here if not in extents fmt */
+       if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+               return generic_block_fiemap(inode, fieinfo, start, len,
+                       ext4_get_block);
+
+       if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
+               return -EBADR;
+
+       if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
+               error = ext4_xattr_fiemap(inode, fieinfo);
+       } else {
+               start_blk = start >> inode->i_sb->s_blocksize_bits;
+               len_blks = len >> inode->i_sb->s_blocksize_bits;
+
+               /*
+                * Walk the extent tree gathering extent information.
+                * ext4_ext_fiemap_cb will push extents back to user.
+                */
+               down_write(&EXT4_I(inode)->i_data_sem);
+               error = ext4_ext_walk_space(inode, start_blk, len_blks,
+                                         ext4_ext_fiemap_cb, fieinfo);
+               up_write(&EXT4_I(inode)->i_data_sem);
+       }
+
+       return error;
+}