Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog

[linux-2.6-omap-h63xx.git] / fs / xfs / xfs_iomap.c

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 7edcde691d1a2539e340db2e83769ad12188e6e6..67f22b2b44b3c41c51ce3ac6c1f911f5db47b181 100644 (file)
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -889,6 +889,16 @@ xfs_iomap_write_unwritten(
        count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
        count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
 
+       /*
+        * Reserve enough blocks in this transaction for two complete extent
+        * btree splits.  We may be converting the middle part of an unwritten
+        * extent and in this case we will insert two new extents in the btree
+        * each of which could cause a full split.
+        *
+        * This reservation amount will be used in the first call to
+        * xfs_bmbt_split() to select an AG with enough space to satisfy the
+        * rest of the operation.
+        */
        resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
 
        do {