Re: [PATCH v2 7/7] xfs: factor xfs_da3_blkinfo verification into common helper

[Brian Foster <bfoster@redhat.com>]

On Thu, Jan 31, 2019 at 09:51:13AM -0800, Darrick J. Wong wrote:
> On Thu, Jan 31, 2019 at 10:46:08AM -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>
> > ---
> >  fs/xfs/libxfs/xfs_attr_leaf.c | 17 +++----------
> >  fs/xfs/libxfs/xfs_da_btree.c  | 46 +++++++++++++++++++++++++----------
> >  fs/xfs/libxfs/xfs_da_format.h |  2 ++
> >  fs/xfs/libxfs/xfs_dir2_leaf.c | 18 +++-----------
> >  4 files changed, 43 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..bf0c53bd2e60 100644
> > --- a/fs/xfs/libxfs/xfs_da_format.h
> > +++ b/fs/xfs/libxfs/xfs_da_format.h
> > @@ -869,4 +869,6 @@ 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 *, struct xfs_da3_blkinfo*);
> 
> Specify parameter names in the declaration, please.
> 

Ok, will fix.

Brian

> --D
> 
> > +
> >  #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
> >