Commit 939919cc authored Apr 11, 2026 by Yuto Ohnuki Committed by Carlos Maiolino Apr 27, 2026

xfs: check directory data block header padding in scrub



Add the missing scrub check for the pad field in directory data block
headers. Old kernels may have written non-zero padding without issue,
and the write path now self-heals stale padding on modification. Flag
non-zero padding as an optimization opportunity (preen) rather than
corruption.

Add xchk_fblock_set_preen helper for reporting file fork block issues
that could be optimized. The trace event xchk_fblock_preen already
exists.

Signed-off-by: Yuto Ohnuki <ytohnuki@amazon.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

parent 8fbb1877

fs/xfs/scrub/common.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -251,6 +251,17 @@ xchk_ino_set_preen(
		trace_xchk_ino_preen(sc, ino, __return_address);
		}

		/* Record a block indexed by a file fork that could be optimized. */
		void
		xchk_fblock_set_preen(
		struct xfs_scrub *sc,
		int whichfork,
		xfs_fileoff_t offset)
		{
		sc->sm->sm_flags \|= XFS_SCRUB_OFLAG_PREEN;
		trace_xchk_fblock_preen(sc, whichfork, offset, __return_address);
		}

		/* Record something being wrong with the filesystem primary superblock. */
		void
		xchk_set_corrupt(

fs/xfs/scrub/common.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -25,6 +25,8 @@ bool xchk_fblock_xref_process_error(struct xfs_scrub *sc,
		void xchk_block_set_preen(struct xfs_scrub *sc,
		struct xfs_buf *bp);
		void xchk_ino_set_preen(struct xfs_scrub *sc, xfs_ino_t ino);
		void xchk_fblock_set_preen(struct xfs_scrub *sc,
		int whichfork, xfs_fileoff_t offset);

		void xchk_set_corrupt(struct xfs_scrub *sc);
		void xchk_block_set_corrupt(struct xfs_scrub *sc,

fs/xfs/scrub/dir.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -492,7 +492,12 @@ xchk_directory_data_bestfree(
		goto out;
		xchk_buffer_recheck(sc, bp);

		/* XXX: Check xfs_dir3_data_hdr.pad is zero once we start setting it. */
		if (xfs_has_crc(sc->mp)) {
		struct xfs_dir3_data_hdr *hdr3 = bp->b_addr;

		if (hdr3->pad)
		xchk_fblock_set_preen(sc, XFS_DATA_FORK, lblk);
		}

		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
		goto out_buf;