From: Yuto Ohnuki <ytohnuki@amazon.com>
Date: Sat, 11 Apr 2026 14:24:15 +0000 (+0100)
Subject: xfs: check directory data block header padding in scrub
X-Git-Tag: v7.1-rc4~19^2~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=939919ccddfcc379bb82b1f90f732d9a5cb32cc8;p=thirdparty%2Flinux.git

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>
---

diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 20e63069088b..3d40cb0b2496 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -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(
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index f2ecc68538f0..b494d747c008 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -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,
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index e09724cd3725..09715a4aa154 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -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;