From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
In process_node_dir2, we need to distinguish between a directory with a
single leafn block (yes, they exist) having no interior da nodes, and a
directory with a da tree that incorrectly points to dablk 0. If we
happened to fill out any part of the da cursor then we have a da btree
with garbage in it; otherwise, we have a single leafn block.
This was found by repair repeatedly rebuilding a directory containing a
single leafn block (xfs/495).
Fixes: 67a79e2cc932 ("xfs_repair: treat zero da btree pointers as corruption")
Reported-by: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
v2: now that the regression test has landed, mention that in the
changelog
---
repair/dir2.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/repair/dir2.c b/repair/dir2.c
index ba5763ed..e67ec590 100644
--- a/repair/dir2.c
+++ b/repair/dir2.c
@@ -1243,10 +1243,21 @@ process_node_dir2(
/*
* Skip directories with a root marked XFS_DIR2_LEAFN_MAGIC
+ *
+ * Be careful here: If any level of the da cursor was filled out then
+ * the directory has a da btree containing an invalid before pointer to
+ * dblock 0, and we should move on to rebuilding the directory. If no
+ * levels in the da cursor got filled out, then we just have a single
+ * leafn block and we're done.
*/
if (bno == 0) {
- release_da_cursor(mp, &da_cursor, 0);
- return 0;
+ if (da_cursor.active > 0) {
+ err_release_da_cursor(mp, &da_cursor, 0);
+ return 1;
+ } else {
+ release_da_cursor(mp, &da_cursor, 0);
+ return 0;
+ }
} else {
/*
* Now pass cursor and bno into leaf-block processing routine.
