[PATCH 37/37] repair: fix leaf node directory data check

Dave Chinner
2013-11-06T01:07:46Z

When walking the leaf node format blocks (LEAFN) in the hash index
of a large directory, we could trip over btree node blocks (DA_NODE)
in the address space if there are enough entries in the directory.
These cause a verifier failure, and hence the directory is
considered corrupt and is trashed and rebuilt unnecesarily. Fix this
by using the correct verifier that can handle both types of blocks
without triggering failures.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
repair/phase6.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/repair/phase6.c b/repair/phase6.c
index 5307acf..d2d4a44 100644
--- a/repair/phase6.c
+++ b/repair/phase6.c
@@ -1937,8 +1937,16 @@ longform_dir2_check_node(
next_da_bno = da_bno + mp->m_dirblkfsbs - 1;
if (bmap_next_offset(NULL, ip, &next_da_bno, XFS_DATA_FORK))
break;
+
+ /*
+ * we need to use the da3 node verifier here as it handles the
+ * fact that reading the leaf hash tree blocks can return either
+ * leaf or node blocks and calls the correct verifier. If we get
+ * a node block, then we'll skip it below based on a magic
+ * number check.
+ */
if (libxfs_da_read_buf(NULL, ip, da_bno, -1, &bp,
- XFS_DATA_FORK, &xfs_dir3_leafn_buf_ops)) {
+ XFS_DATA_FORK, &xfs_da3_node_buf_ops)) {
do_warn(
_("can't read leaf block %u for directory inode %" PRIu64 "\n"),
da_bno, ip->i_ino);