[PATCH] ext4: fix credit calculation in ext4_ext_calc_credits_for_insert

Fix a nit in ext4_ext_calc_credits_for_insert().  Besides, credits for the
new root are already added in the index split accounting.

Signed-off-by: Johann Lombardi <johann.lombardi@bull.net>
Signed-off-by: Alex Tomas <alex@clusterfs.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1442ccbaea79..994a6e450e06 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1531,16 +1531,17 @@ int inline ext4_ext_calc_credits_for_insert(struct inode *inode,
 
         /*
          * tree can be full, so it would need to grow in depth:
-         * allocation + old root + new root
+         * we need one credit to modify old root, credits for
+         * new root will be added in split accounting
          */
-        needed += 2 + 1 + 1;
+        needed += 1;
 
         /*
          * 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);
+        needed += (depth * 2) + (depth * 2);
 
         /* any allocation modifies superblock */
         needed += 1;