1 files changed, 32 insertions, 23 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 42c4c0c892ed..612c3d2c3824 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -99,7 +99,7 @@ static int ext4_ext_journal_restart(handle_t *handle, int needed)
         if (handle->h_buffer_credits > needed)
                 return 0;
         err = ext4_journal_extend(handle, needed);
-        if (err)
+        if (err <= 0)
                 return err;
         return ext4_journal_restart(handle, needed);
 }
@@ -1441,7 +1441,7 @@ 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);
@@ -1910,9 +1910,13 @@ 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;
@@ -2323,7 +2327,10 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                 unsigned int newdepth;
                 /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
                 if (allocated <= EXT4_EXT_ZERO_LEN) {
-                        /* Mark first half uninitialized.
+                        /*
+                         * 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
                          */
@@ -2346,7 +2353,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                                 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)
@@ -2374,6 +2381,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                                         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);
@@ -2403,6 +2411,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                         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)
@@ -2418,23 +2427,22 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                  */
                 orig_ex.ee_len = cpu_to_le16(ee_len -
                                                 ext4_ext_get_actual_len(ex3));
-                if (newdepth != depth) {
-                        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;
+                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
@@ -2452,6 +2460,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                         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;
                 }
         }