xfs: sb verifier doesn't handle uncached sb buffer

Source kernel commit: 8cf07f3dd56195316be97758cb8b4e1d7183ea84

The verifier checks explicitly for bp->b_bn == XFS_SB_DADDR to match
the primary superblock buffer, but the primary superblock is an
uncached buffer and so bp->b_bn is always -1ULL. Hence this never
matches and the CRC error reporting is wholly dependent on the
mount superblock already being populated so CRC feature checks pass
and allow CRC errors to be reported.

Fix this so that the primary superblock CRC error reporting is not
dependent on already having read the superblock into memory.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/libxfs/xfs_sb.c b/libxfs/xfs_sb.c
index b2e214ee783e3abf19a5807ca21b2fd6eb4b216b..f29a59ae807b283790497a47d32808da89c53cf9 100644 (file)
--- a/libxfs/xfs_sb.c
+++ b/libxfs/xfs_sb.c
@@ -634,7 +634,7 @@ xfs_sb_read_verify(
 
                if (!xfs_buf_verify_cksum(bp, XFS_SB_CRC_OFF)) {
                        /* Only fail bad secondaries on a known V5 filesystem */
-                       if (bp->b_bn == XFS_SB_DADDR ||
+                       if (bp->b_maps[0].bm_bn == XFS_SB_DADDR ||
                            xfs_sb_version_hascrc(&mp->m_sb)) {
                                error = -EFSBADCRC;
                                goto out_error;