Re: [PATCH v3 9/9] xfs: factor xfs_da3_blkinfo verification into common helper

Darrick J. Wong
2019-02-06T18:16:14Z

On Mon, Feb 04, 2019 at 09:52:31AM -0500, Brian Foster wrote:
> With the verifier magic value helper in place, we've left a bit more
> duplicate code across the verifiers that involve struct
> xfs_da3_blkinfo. This includes the da node, xattr leaf and dir leaf
> verifiers, all of which perform similar checks for v4 and v5
> filesystems.
>
> Create a common helper to verify an xfs_da3_blkinfo structure,
> taking care to only access v5 fields where appropriate, and refactor
> the aforementioned verifiers to use the helper. No functional
> changes.
>
> Signed-off-by: Brian Foster <bfoster@redhat.com>

Seems ok modulo the questions I had about the ASSERT,

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
> fs/xfs/libxfs/xfs_attr_leaf.c | 17 +++----------
> fs/xfs/libxfs/xfs_da_btree.c | 46 +++++++++++++++++++++++++----------
> fs/xfs/libxfs/xfs_da_format.h | 3 +++
> fs/xfs/libxfs/xfs_dir2_leaf.c | 18 +++-----------
> 4 files changed, 44 insertions(+), 40 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
> index dde3a550d7ce..0c92987f57fc 100644
> --- a/fs/xfs/libxfs/xfs_attr_leaf.c
> +++ b/fs/xfs/libxfs/xfs_attr_leaf.c
> @@ -245,23 +245,14 @@ xfs_attr3_leaf_verify(
> struct xfs_attr_leaf_entry *entries;
> uint32_t end; /* must be 32bit - see below */
> int i;
> + xfs_failaddr_t fa;
>
> xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
>
> - if (!xfs_verify_magic(bp, leaf->hdr.info.magic))
> - return __this_address;
> -
> - if (xfs_sb_version_hascrc(&mp->m_sb)) {
> - struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
> + fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
> + if (fa)
> + return fa;
>
> - ASSERT(leaf->hdr.info.magic == hdr3->info.hdr.magic);
> - if (!uuid_equal(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid))
> - return __this_address;
> - if (be64_to_cpu(hdr3->info.blkno) != bp->b_bn)
> - return __this_address;
> - if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->info.lsn)))
> - return __this_address;
> - }
> /*
> * In recovery there is a transient state where count == 0 is valid
> * because we may have transitioned an empty shortform attr to a leaf
> diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c
> index 6b8ca390eecc..622f88a1b1aa 100644
> --- a/fs/xfs/libxfs/xfs_da_btree.c
> +++ b/fs/xfs/libxfs/xfs_da_btree.c
> @@ -116,6 +116,35 @@ xfs_da_state_free(xfs_da_state_t *state)
> kmem_zone_free(xfs_da_state_zone, state);
> }
>
> +/*
> + * Verify an xfs_da3_blkinfo structure. Note that the da3 fields are only
> + * accessible on v5 filesystems. This header format is common across da node,
> + * attr leaf and dir leaf blocks.
> + */
> +xfs_failaddr_t
> +xfs_da3_blkinfo_verify(
> + struct xfs_buf *bp,
> + struct xfs_da3_blkinfo *hdr3)
> +{
> + struct xfs_mount *mp = bp->b_target->bt_mount;
> + struct xfs_da_blkinfo *hdr = &hdr3->hdr;
> +
> + if (!xfs_verify_magic(bp, hdr->magic))
> + return __this_address;
> +
> + if (xfs_sb_version_hascrc(&mp->m_sb)) {
> + ASSERT(hdr3->hdr.magic == hdr->magic);
> + if (!uuid_equal(&hdr3->uuid, &mp->m_sb.sb_meta_uuid))
> + return __this_address;
> + if (be64_to_cpu(hdr3->blkno) != bp->b_bn)
> + return __this_address;
> + if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->lsn)))
> + return __this_address;
> + }
> +
> + return 0;
> +}
> +
> static xfs_failaddr_t
> xfs_da3_node_verify(
> struct xfs_buf *bp)
> @@ -124,25 +153,16 @@ xfs_da3_node_verify(
> struct xfs_da_intnode *hdr = bp->b_addr;
> struct xfs_da3_icnode_hdr ichdr;
> const struct xfs_dir_ops *ops;
> + xfs_failaddr_t fa;
>
> ops = xfs_dir_get_ops(mp, NULL);
>
> ops->node_hdr_from_disk(&ichdr, hdr);
>
> - if (!xfs_verify_magic(bp, hdr->hdr.info.magic))
> - return __this_address;
> + fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
> + if (fa)
> + return fa;
>
> - if (xfs_sb_version_hascrc(&mp->m_sb)) {
> - struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
> -
> - ASSERT(hdr3->info.hdr.magic == hdr->hdr.info.magic);
> - if (!uuid_equal(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid))
> - return __this_address;
> - if (be64_to_cpu(hdr3->info.blkno) != bp->b_bn)
> - return __this_address;
> - if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->info.lsn)))
> - return __this_address;
> - }
> if (ichdr.level == 0)
> return __this_address;
> if (ichdr.level > XFS_DA_NODE_MAXDEPTH)
> diff --git a/fs/xfs/libxfs/xfs_da_format.h b/fs/xfs/libxfs/xfs_da_format.h
> index 5d5bf3bffc78..ae654e06b2fb 100644
> --- a/fs/xfs/libxfs/xfs_da_format.h
> +++ b/fs/xfs/libxfs/xfs_da_format.h
> @@ -869,4 +869,7 @@ static inline unsigned int xfs_dir2_dirblock_bytes(struct xfs_sb *sbp)
> return 1 << (sbp->sb_blocklog + sbp->sb_dirblklog);
> }
>
> +xfs_failaddr_t xfs_da3_blkinfo_verify(struct xfs_buf *bp,
> + struct xfs_da3_blkinfo *hdr3);
> +
> #endif /* __XFS_DA_FORMAT_H__ */
> diff --git a/fs/xfs/libxfs/xfs_dir2_leaf.c b/fs/xfs/libxfs/xfs_dir2_leaf.c
> index a99ae2cd292e..094028b7b162 100644
> --- a/fs/xfs/libxfs/xfs_dir2_leaf.c
> +++ b/fs/xfs/libxfs/xfs_dir2_leaf.c
> @@ -146,21 +146,11 @@ xfs_dir3_leaf_verify(
> {
> struct xfs_mount *mp = bp->b_target->bt_mount;
> struct xfs_dir2_leaf *leaf = bp->b_addr;
> + xfs_failaddr_t fa;
>
> - if (!xfs_verify_magic(bp, leaf->hdr.info.magic))
> - return __this_address;
> -
> - if (xfs_sb_version_hascrc(&mp->m_sb)) {
> - struct xfs_dir3_leaf_hdr *leaf3 = bp->b_addr;
> -
> - ASSERT(leaf3->info.hdr.magic == leaf->hdr.info.magic);
> - if (!uuid_equal(&leaf3->info.uuid, &mp->m_sb.sb_meta_uuid))
> - return __this_address;
> - if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn)
> - return __this_address;
> - if (!xfs_log_check_lsn(mp, be64_to_cpu(leaf3->info.lsn)))
> - return __this_address;
> - }
> + fa = xfs_da3_blkinfo_verify(bp, bp->b_addr);
> + if (fa)
> + return fa;
>
> return xfs_dir3_leaf_check_int(mp, NULL, NULL, leaf);
> }
> --
> 2.17.2
>