[PATCH 03/10] xfs: don't walk off the end of a null sc->sa.agi_bp in AGI repair

From: Darrick J. Wong <[email protected]>

LOLLM noticed a longstanding bug where xrep_iunlink_walk_ondisk_bucket
tries to walk ragi->sc->sa.agi_bp to rebuild the unlinked inode lists.
Unfortunately, it's possible for agi_bp to be null if the buffer
verifier fails, so we have to use ragi->agi_bp (which skips verifier
checks) instead.

Cc: <[email protected]> # v6.10
Fixes: ab97f4b1c03075 ("xfs: repair AGI unlinked inode bucket lists")
Signed-off-by: "Darrick J. Wong" <[email protected]>
Assisted-by: LOLLM # finding obvious bugs
Reviewed-by: Christoph Hellwig <[email protected]>
---
 fs/xfs/scrub/agheader_repair.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
index 13074d5e319cc0..39468b8fa9863d 100644
--- a/fs/xfs/scrub/agheader_repair.c
+++ b/fs/xfs/scrub/agheader_repair.c
@@ -1082,7 +1082,7 @@ xrep_iunlink_walk_ondisk_bucket(
 {
 	struct xagino_bitmap	seen;
 	struct xfs_scrub	*sc = ragi->sc;
-	struct xfs_agi		*agi = sc->sa.agi_bp->b_addr;
+	struct xfs_agi		*agi = ragi->agi_bp->b_addr;
 	xfs_agino_t		prev_agino = NULLAGINO;
 	xfs_agino_t		next_agino;
 	int			error = 0;