[PATCH 1/3] xfs: check AGI unlinked inode buckets

Darrick J. Wong
2024-03-27T02:06:09Z

Look for corruptions in the AGI unlinked bucket chains.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/scrub/agheader.c | 40 ++++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_inode.c | 2 +-
fs/xfs/xfs_inode.h | 1 +
3 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/scrub/agheader.c b/fs/xfs/scrub/agheader.c
index e954f07679dd7..1528f14bd9251 100644
--- a/fs/xfs/scrub/agheader.c
+++ b/fs/xfs/scrub/agheader.c
@@ -15,6 +15,7 @@
#include "xfs_ialloc.h"
#include "xfs_rmap.h"
#include "xfs_ag.h"
+#include "xfs_inode.h"
#include "scrub/scrub.h"
#include "scrub/common.h"

@@ -865,6 +866,43 @@ xchk_agi_xref(
/* scrub teardown will take care of sc->sa for us */
}

+/*
+ * Check the unlinked buckets for links to bad inodes. We hold the AGI, so
+ * there cannot be any threads updating unlinked list pointers in this AG.
+ */
+STATIC void
+xchk_iunlink(
+ struct xfs_scrub *sc,
+ struct xfs_agi *agi)
+{
+ unsigned int i;
+ struct xfs_inode *ip;
+
+ for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
+ xfs_agino_t agino = be32_to_cpu(agi->agi_unlinked[i]);
+
+ while (agino != NULLAGINO) {
+ if (agino % XFS_AGI_UNLINKED_BUCKETS != i) {
+ xchk_block_set_corrupt(sc, sc->sa.agi_bp);
+ return;
+ }
+
+ ip = xfs_iunlink_lookup(sc->sa.pag, agino);
+ if (!ip) {
+ xchk_block_set_corrupt(sc, sc->sa.agi_bp);
+ return;
+ }
+
+ if (!xfs_inode_on_unlinked_list(ip)) {
+ xchk_block_set_corrupt(sc, sc->sa.agi_bp);
+ return;
+ }
+
+ agino = ip->i_next_unlinked;
+ }
+ }
+}
+
/* Scrub the AGI. */
int
xchk_agi(
@@ -949,6 +987,8 @@ xchk_agi(
if (pag->pagi_freecount != be32_to_cpu(agi->agi_freecount))
xchk_block_set_corrupt(sc, sc->sa.agi_bp);

+ xchk_iunlink(sc, agi);
+
xchk_agi_xref(sc);
out:
return error;
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index c0bdcf0f2448e..666bd03cf05c3 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1974,7 +1974,7 @@ xfs_inactive(
* only unlinked, referenced inodes can be on the unlinked inode list. If we
* don't find the inode in cache, then let the caller handle the situation.
*/
-static struct xfs_inode *
+struct xfs_inode *
xfs_iunlink_lookup(
struct xfs_perag *pag,
xfs_agino_t agino)
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 66271daff5b3f..8754e1969350d 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -619,6 +619,7 @@ bool xfs_inode_needs_inactive(struct xfs_inode *ip);
int xfs_iunlink(struct xfs_trans *tp, struct xfs_inode *ip);
int xfs_iunlink_remove(struct xfs_trans *tp, struct xfs_perag *pag,
struct xfs_inode *ip);
+struct xfs_inode *xfs_iunlink_lookup(struct xfs_perag *pag, xfs_agino_t agino);

void xfs_end_io(struct work_struct *work);