On Tue, Aug 10, 2021 at 03:24:36PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
Not sure why this isn't in the series with xfs_buf_daddr and the other
cleanups, but the changes look correct to me.
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> fs/xfs/libxfs/xfs_sb.c | 2 +-
> fs/xfs/xfs_buf.h | 7 ++++++-
> 2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index 04f5386446db..4a4586bd2ba2 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -636,7 +636,7 @@ 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;
> diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
> index cfbe37d73293..37c9004f11de 100644
> --- a/fs/xfs/xfs_buf.h
> +++ b/fs/xfs/xfs_buf.h
> @@ -133,7 +133,12 @@ struct xfs_buf {
> * fast-path on locking.
> */
> struct rhash_head b_rhash_head; /* pag buffer hash node */
> - xfs_daddr_t b_bn; /* block number of buffer */
> +
> + /*
> + * b_bn is the cache index. Do not use directly, use b_maps[0].bm_bn
> + * for the buffer disk address instead.
> + */
> + xfs_daddr_t b_bn;
> int b_length; /* size of buffer in BBs */
> atomic_t b_hold; /* reference count */
> atomic_t b_lru_ref; /* lru reclaim ref count */
> --
> 2.31.1
>
