fs: symlink write_begin allocation context fix
[safe/jmp/linux-2.6] / fs / ext4 / extents.c
index ded3d46..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/jbd2.h>
 #include <linux/highuid.h>
 #include <linux/pagemap.h>
 #include <linux/quotaops.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/falloc.h>
-#include <linux/ext4_fs_extents.h>
 #include <asm/uaccess.h>
+#include <linux/fiemap.h>
+#include "ext4_jbd2.h"
+#include "ext4_extents.h"
 
 
 /*
@@ -52,7 +53,7 @@ static ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
 {
        ext4_fsblk_t block;
 
-       block = le32_to_cpu(ex->ee_start);
+       block = le32_to_cpu(ex->ee_start_lo);
        block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1;
        return block;
 }
@@ -61,11 +62,11 @@ static 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 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);
+       block = le32_to_cpu(ix->ei_leaf_lo);
        block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1;
        return block;
 }
@@ -75,9 +76,9 @@ static 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 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));
+       ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
        ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
 }
 
@@ -88,51 +89,20 @@ static void ext4_ext_store_pblock(struct ext4_extent *ex, 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));
+       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);
 }
 
 /*
@@ -174,10 +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;
 
@@ -199,20 +170,28 @@ 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;
 }
 
@@ -270,6 +249,100 @@ static int ext4_ext_space_root_idx(struct inode *inode)
        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)
 {
@@ -311,11 +384,11 @@ static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
        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;
@@ -330,34 +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
        {
@@ -368,9 +441,10 @@ 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));
                        }
@@ -389,16 +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:
@@ -407,10 +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;
@@ -418,8 +491,9 @@ 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;
@@ -462,18 +536,18 @@ 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) {
@@ -484,11 +558,14 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
                alloc = 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;
@@ -505,20 +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);
 
@@ -554,7 +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));
@@ -565,7 +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));
@@ -575,7 +651,7 @@ 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));
@@ -649,7 +725,8 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        /* 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;
@@ -697,7 +774,7 @@ 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);
@@ -714,8 +791,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                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);
+               le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
                err = ext4_ext_dirty(handle, inode, path + depth);
                if (err)
                        goto cleanup;
@@ -733,7 +809,7 @@ 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;
@@ -753,9 +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 %llu): %lu -> %llu\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++;
@@ -765,7 +840,7 @@ 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 %llu\n", i,
+                       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);
@@ -779,8 +854,7 @@ 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);
@@ -796,7 +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;
@@ -821,7 +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);
@@ -848,7 +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;
 
@@ -894,8 +968,13 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
        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);
@@ -940,12 +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 {
@@ -957,8 +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;
@@ -980,13 +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;
@@ -1019,7 +1244,7 @@ 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,
+static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
                                        struct ext4_ext_path *path)
 {
        int depth;
@@ -1037,7 +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--;
        }
 
@@ -1050,7 +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;
@@ -1107,7 +1333,7 @@ static int
 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
                                struct ext4_extent *ex2)
 {
-       unsigned short ext1_ee_len, ext2_ee_len;
+       unsigned short ext1_ee_len, ext2_ee_len, max_len;
 
        /*
         * Make sure that either both extents are uninitialized, or
@@ -1116,6 +1342,11 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
        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);
 
@@ -1128,10 +1359,10 @@ 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 (ext1_ee_len + ext2_ee_len > EXT_MAX_LEN)
+       if (ext1_ee_len + ext2_ee_len > max_len)
                return 0;
 #ifdef AGGRESSIVE_TEST
-       if (le16_to_cpu(ex1->ee_len) >= 4)
+       if (ext1_ee_len >= 4)
                return 0;
 #endif
 
@@ -1176,7 +1407,7 @@ int ext4_ext_try_to_merge(struct inode *inode,
                                * sizeof(struct ext4_extent);
                        memmove(ex + 1, ex + 2, len);
                }
-               eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries) - 1);
+               le16_add_cpu(&eh->eh_entries, -1);
                merge_done = 1;
                WARN_ON(eh->eh_entries == 0);
                if (!eh->eh_entries)
@@ -1199,7 +1430,7 @@ unsigned int ext4_ext_check_overlap(struct inode *inode,
                                    struct ext4_extent *newext,
                                    struct ext4_ext_path *path)
 {
-       unsigned long b1, b2;
+       ext4_lblk_t b1, b2;
        unsigned int depth, len1;
        unsigned int ret = 0;
 
@@ -1212,7 +1443,7 @@ unsigned int ext4_ext_check_overlap(struct inode *inode,
 
        /*
         * get the next allocated block if the extent in the path
-        * is before the requested block(s) 
+        * is before the requested block(s)
         */
        if (b2 < b1) {
                b2 = ext4_ext_next_allocated_block(path);
@@ -1220,7 +1451,7 @@ unsigned int ext4_ext_check_overlap(struct inode *inode,
                        goto out;
        }
 
-       /* check for wrap through zero */
+       /* 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);
@@ -1246,11 +1477,12 @@ 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(ext4_ext_get_actual_len(newext) == 0);
@@ -1366,11 +1598,10 @@ has_space:
                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:
@@ -1396,15 +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);
@@ -1473,11 +1704,12 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
                }
 
                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) {
@@ -1503,8 +1735,8 @@ int ext4_ext_walk_space(struct inode *inode, unsigned long block,
 }
 
 static void
-ext4_ext_put_in_cache(struct inode *inode, __u32 block,
-                       __u32 len, __u32 start, int type)
+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);
@@ -1522,10 +1754,11 @@ ext4_ext_put_in_cache(struct inode *inode, __u32 block,
  */
 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;
@@ -1537,32 +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) ext4_ext_get_actual_len(ex));
+               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)
                        + ext4_ext_get_actual_len(ex)) {
+               ext4_lblk_t next;
                lblock = le32_to_cpu(ex->ee_block)
                        + ext4_ext_get_actual_len(ex);
-               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) ext4_ext_get_actual_len(ex),
-                               (unsigned long) block);
-               BUG_ON(len == lblock);
-               len = len - lblock;
+
+               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 int
-ext4_ext_in_cache(struct inode *inode, unsigned long block,
+ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
                        struct ext4_extent *ex)
 {
        struct ext4_ext_cache *cex;
@@ -1579,11 +1814,9 @@ ext4_ext_in_cache(struct inode *inode, unsigned long 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:%llu\n",
-                               (unsigned long) block,
-                               (unsigned long) cex->ec_block,
-                               (unsigned long) cex->ec_len,
-                               cex->ec_start);
+               ext_debug("%u cached by %u:%u:%llu\n",
+                               block,
+                               cex->ec_block, cex->ec_len, cex->ec_start);
                return cex->ec_type;
        }
 
@@ -1597,7 +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;
@@ -1611,76 +1844,85 @@ int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
        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);
+       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 %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 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;
-       }
-
-       /*
-        * 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;
+                               < le16_to_cpu(path[depth].p_hdr->eh_max)) {
 
-       /* 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:
-        * we need one credit to modify old root, credits for
-        * new root will be added in split accounting
-        */
-       needed += 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;
        unsigned short ee_len =  ext4_ext_get_actual_len(ex);
-       int i;
+       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);
@@ -1699,47 +1941,49 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
        if (from >= le32_to_cpu(ex->ee_block)
            && 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) + ee_len - from;
                start = ext_pblock(ex) + ee_len - num;
-               ext_debug("free last %lu blocks starting %llu\n", num, start);
+               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) + ee_len - 1) {
-               printk("strange request: removal %lu-%lu from %u:%u\n",
+               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), 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);
@@ -1782,22 +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)
@@ -1810,12 +2054,16 @@ 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);
-               if (uninitialized)
+               /*
+                * 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);
@@ -1862,7 +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);
@@ -1870,7 +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);
@@ -1883,13 +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 = kzalloc(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;
        }
        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;
        }
@@ -1910,17 +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);
@@ -1937,17 +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 %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 */
@@ -2002,7 +2251,7 @@ void ext4_ext_init(struct super_block *sb)
         */
 
        if (test_opt(sb, EXTENTS)) {
-               printk("EXT4-fs: file extents enabled");
+               printk(KERN_INFO "EXT4-fs: file extents enabled");
 #ifdef AGGRESSIVE_TEST
                printk(", aggressive tests");
 #endif
@@ -2041,6 +2290,82 @@ 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
@@ -2051,17 +2376,19 @@ void ext4_ext_release(struct super_block *sb)
  *   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
  */
-int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
-                                       struct ext4_ext_path *path,
-                                       ext4_fsblk_t iblock,
-                                       unsigned long max_blocks)
+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;
+       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;
-       unsigned int allocated, ee_block, ee_len, depth;
+       ext4_lblk_t ee_block;
+       unsigned int allocated, ee_len, depth;
        ext4_fsblk_t newblock;
        int err = 0;
        int ret = 0;
@@ -2074,6 +2401,26 @@ int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
        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) {
@@ -2092,33 +2439,144 @@ int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
        /* 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)
-                       goto out;
+               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);
-               if (newdepth != depth) {
-                       depth = newdepth;
-                       path = ext4_ext_find_extent(inode, iblock, NULL);
-                       if (IS_ERR(path)) {
-                               err = PTR_ERR(path);
-                               path = NULL;
-                               goto out;
-                       }
-                       eh = path[depth].p_hdr;
-                       ex = path[depth].p_ext;
-                       if (ex2 != &newex)
-                               ex2 = ex;
+               /*
+                * 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
@@ -2133,14 +2591,10 @@ int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
        }
        /* ex2: iblock to iblock + maxblocks-1 : initialised */
        ex2->ee_block = cpu_to_le32(iblock);
-       ex2->ee_start = cpu_to_le32(newblock);
        ext4_ext_store_pblock(ex2, newblock);
        ex2->ee_len = cpu_to_le16(allocated);
        if (ex2 != ex)
                goto insert;
-       err = ext4_ext_get_access(handle, inode, path + depth);
-       if (err)
-               goto out;
        /*
         * New (initialized) extent starts from the first block
         * in the current extent. i.e., ex2 == ex
@@ -2179,12 +2633,51 @@ int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
        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)
 {
@@ -2194,11 +2687,12 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
        ext4_fsblk_t goal, newblock;
        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 */
        goal = ext4_ext_in_cache(inode, iblock, &newex);
@@ -2218,7 +2712,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                                   - 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 {
@@ -2246,7 +2740,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 
        ex = path[depth].p_ext;
        if (ex) {
-               unsigned long ee_block = le32_to_cpu(ex->ee_block);
+               ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
                ext4_fsblk_t ee_start = ext_pblock(ex);
                unsigned short ee_len;
 
@@ -2260,7 +2754,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                        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 -> %llu\n", (int) iblock,
+                       ext_debug("%u fit into %lu:%d -> %llu\n", iblock,
                                        ee_block, ee_len, newblock);
 
                        /* Do not put uninitialized extent in the cache */
@@ -2272,15 +2766,27 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                        }
                        if (create == EXT4_CREATE_UNINITIALIZED_EXT)
                                goto out;
-                       if (!create)
+                       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)
+                       if (ret <= 0) {
+                               err = ret;
                                goto out2;
-                       else
+                       else
                                allocated = ret;
                        goto outnew;
                }
@@ -2299,24 +2805,52 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                goto out2;
        }
        /*
-        * Okay, we need to do block allocation.  Lazily initialize the block
-        * allocation info here if necessary.
+        * Okay, we need to do block allocation.
         */
-       if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info))
-               ext4_init_block_alloc_info(inode);
 
-       /* allocate new block */
-       goal = ext4_ext_find_goal(inode, path, iblock);
+       /* 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 = le16_to_cpu(newex.ee_len);
+               allocated = ext4_ext_get_actual_len(&newex);
        else
                allocated = max_blocks;
-       newblock = ext4_new_blocks(handle, inode, goal, &allocated, &err);
+
+       /* allocate new block */
+       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 %llu, found %llu/%lu\n",
@@ -2324,24 +2858,33 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 
        /* try to insert new extent into found leaf and return */
        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) {
                /* 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),
-                                       le16_to_cpu(newex.ee_len));
+                                       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);
+       allocated = ext4_ext_get_actual_len(&newex);
 outnew:
-       __set_bit(BH_New, &bh_result->b_state);
+       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);
 
        /* Cache only when it is _not_ an uninitialized extent */
        if (create != EXT4_CREATE_UNINITIALIZED_EXT)
@@ -2351,7 +2894,7 @@ 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:
@@ -2359,47 +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;
@@ -2416,6 +2953,7 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
                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.
@@ -2426,29 +2964,32 @@ 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);
 }
 
-/*
- * ext4_ext_writepage_trans_blocks:
- * calculate max number of blocks we could modify
- * in order to allocate new block for an inode
- */
-int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
+static void ext4_falloc_update_inode(struct inode *inode,
+                               int mode, loff_t new_size, int update_ctime)
 {
-       int needed;
-
-       needed = ext4_ext_calc_credits_for_insert(inode, NULL);
-
-       /* caller wants to allocate num blocks, but note it includes sb */
-       needed = needed * num - (num - 1);
+       struct timespec now;
 
-#ifdef CONFIG_QUOTA
-       needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
+       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);
+       }
 
-       return needed;
 }
 
 /*
@@ -2461,8 +3002,9 @@ 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)
 {
        handle_t *handle;
-       ext4_fsblk_t block, max_blocks;
-       ext4_fsblk_t nblocks = 0;
+       ext4_lblk_t block;
+       loff_t new_size;
+       unsigned long max_blocks;
        int ret = 0;
        int ret2 = 0;
        int retries = 0;
@@ -2481,14 +3023,17 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
                return -ENODEV;
 
        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;
-
+                                                       - block;
        /*
-        * credits to insert 1 extent into extent tree + buffers to be able to
-        * modify 1 super block, 1 block bitmap and 1 group descriptor.
+        * credits to insert 1 extent into extent tree
         */
-       credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3;
+       credits = ext4_chunk_trans_blocks(inode, max_blocks);
+       mutex_lock(&inode->i_mutex);
 retry:
        while (ret >= 0 && ret < max_blocks) {
                block = block + ret;
@@ -2498,79 +3043,179 @@ retry:
                        ret = PTR_ERR(handle);
                        break;
                }
-
-               ret = ext4_ext_get_blocks(handle, inode, block,
+               ret = ext4_get_blocks_wrap(handle, inode, block,
                                          max_blocks, &map_bh,
-                                         EXT4_CREATE_UNINITIALIZED_EXT, 0);
-               WARN_ON(!ret);
-               if (!ret) {
-                       ext4_error(inode->i_sb, "ext4_fallocate",
-                                  "ext4_ext_get_blocks returned 0! inode#%lu"
-                                  ", block=%llu, max_blocks=%llu",
-                                  inode->i_ino, block, max_blocks);
-                       ret = -EIO;
+                                         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 (ret > 0) {
-                       /* check wrap through sign-bit/zero here */
-                       if ((block + ret) < 0 || (block + ret) < block) {
-                               ret = -EIO;
-                               ext4_mark_inode_dirty(handle, inode);
-                               ret2 = ext4_journal_stop(handle);
-                               break;
-                       }
-                       if (buffer_new(&map_bh) && ((block + ret) >
-                           (EXT4_BLOCK_ALIGN(i_size_read(inode), blkbits)
-                           >> blkbits)))
-                                       nblocks = nblocks + ret;
-               }
-
-               /* Update ctime if new blocks get allocated */
-               if (nblocks) {
-                       struct timespec now;
-
-                       now = current_fs_time(inode->i_sb);
-                       if (!timespec_equal(&inode->i_ctime, &now))
-                               inode->i_ctime = now;
-               }
+               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))
+       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;
+
+               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;
 
        /*
-        * Time to update the file size.
-        * Update only when preallocation was requested beyond the file size.
+        * 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 (!(mode & FALLOC_FL_KEEP_SIZE) &&
-           (offset + len) > i_size_read(inode)) {
-               if (ret > 0) {
-                       /*
-                        * if no error, we assume preallocation succeeded
-                        * completely
-                        */
-                       mutex_lock(&inode->i_mutex);
-                       i_size_write(inode, offset + len);
-                       EXT4_I(inode)->i_disksize = i_size_read(inode);
-                       mutex_unlock(&inode->i_mutex);
-               } else if (ret < 0 && nblocks) {
-                       /* Handle partial allocation scenario */
-                       loff_t newsize;
-
-                       mutex_lock(&inode->i_mutex);
-                       newsize  = (nblocks << blkbits) + i_size_read(inode);
-                       i_size_write(inode, EXT4_BLOCK_ALIGN(newsize, blkbits));
-                       EXT4_I(inode)->i_disksize = i_size_read(inode);
-                       mutex_unlock(&inode->i_mutex);
-               }
+       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;
+}
+
+/* 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 ret > 0 ? ret2 : ret;
+       return error;
 }
+