[Cluster-devel] [gfs2-utils PATCH 6/7] fsck.gfs2: avoid negative number in leaf depth

[Bob Peterson]

If a leaf block appears many times by mistake in the same hash table,
there's a change it belongs in a different directory's hash table, and
was put there by mistake. In that case, the leaf depth may be too
big for the directory in which it improperly appears. When that happens,
function check_leaf_depth can come up with a negative number when it
calculates the depth. This patch prevents the negative leaf depth error
by flagging an error when it determines the leaf depth is wrong.
The error causes pass2 to relocate the leaf to lost+found when it returns.

rhbz#984085
---
 gfs2/fsck/pass2.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gfs2/fsck/pass2.c b/gfs2/fsck/pass2.c
index 81fbe06..a40a4a7 100644
--- a/gfs2/fsck/pass2.c
+++ b/gfs2/fsck/pass2.c
@@ -276,6 +276,9 @@ static int check_leaf_depth(struct gfs2_inode *ip, uint64_t leaf_no,
 		factor++;
 		divisor >>= 1;
 	}
+	if (ip->i_di.di_depth < factor) /* can't be fixed--leaf must be on the
+					   wrong dinode. */
+		return -1;
 	correct_depth = ip->i_di.di_depth - factor;
 	if (cur_depth == correct_depth)
 		return 0;
-- 
1.8.3.1