Re: [PATCH 4/4] xfs: compare btree block keys to parent block's keys during scrub

[Brian Foster <bfoster@redhat.com>]

On Wed, Oct 25, 2017 at 10:49:43PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> When we're done checking all the records/keys in a btree block, compute
> the low and high key of the block and compare them to the associated key
> in the parent btree block.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---

I guess this one should be stacked on top of a scrub series.. (or the
associated code merged)? Doesn't apply to for-next..

Brian

>  fs/xfs/libxfs/xfs_btree.c |    4 ++--
>  fs/xfs/libxfs/xfs_btree.h |    4 ++++
>  fs/xfs/scrub/btree.c      |   46 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 52 insertions(+), 2 deletions(-)
> 
> 
> diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
> index b3cd82a..848f371 100644
> --- a/fs/xfs/libxfs/xfs_btree.c
> +++ b/fs/xfs/libxfs/xfs_btree.c
> @@ -2027,7 +2027,7 @@ xfs_btree_lookup(
>  }
>  
>  /* Find the high key storage area from a regular key. */
> -STATIC union xfs_btree_key *
> +union xfs_btree_key *
>  xfs_btree_high_key_from_key(
>  	struct xfs_btree_cur	*cur,
>  	union xfs_btree_key	*key)
> @@ -2101,7 +2101,7 @@ xfs_btree_get_node_keys(
>  }
>  
>  /* Derive the keys for any btree block. */
> -STATIC void
> +void
>  xfs_btree_get_keys(
>  	struct xfs_btree_cur	*cur,
>  	struct xfs_btree_block	*block,
> diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
> index be82f41..b57501c 100644
> --- a/fs/xfs/libxfs/xfs_btree.h
> +++ b/fs/xfs/libxfs/xfs_btree.h
> @@ -541,5 +541,9 @@ int64_t xfs_btree_diff_two_ptrs(struct xfs_btree_cur *cur,
>  void xfs_btree_get_sibling(struct xfs_btree_cur *cur,
>  			   struct xfs_btree_block *block,
>  			   union xfs_btree_ptr *ptr, int lr);
> +void xfs_btree_get_keys(struct xfs_btree_cur *cur,
> +		struct xfs_btree_block *block, union xfs_btree_key *key);
> +union xfs_btree_key *xfs_btree_high_key_from_key(struct xfs_btree_cur *cur,
> +		union xfs_btree_key *key);
>  
>  #endif	/* __XFS_BTREE_H__ */
> diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c
> index 9ccf763..9e8b67a 100644
> --- a/fs/xfs/scrub/btree.c
> +++ b/fs/xfs/scrub/btree.c
> @@ -358,6 +358,50 @@ xfs_scrub_btree_get_block(
>  }
>  
>  /*
> + * Check that the low and high keys of this block match the keys stored
> + * in the parent block.
> + */
> +STATIC void
> +xfs_scrub_btree_block_keys(
> +	struct xfs_scrub_btree		*bs,
> +	int				level,
> +	struct xfs_btree_block		*block)
> +{
> +	union xfs_btree_key		block_keys;
> +	struct xfs_btree_cur		*cur = bs->cur;
> +	union xfs_btree_key		*high_bk;
> +	union xfs_btree_key		*parent_keys;
> +	union xfs_btree_key		*high_pk;
> +	struct xfs_btree_block		*parent_block;
> +	struct xfs_buf			*bp;
> +
> +	if (level >= cur->bc_nlevels - 1)
> +		return;
> +
> +	/* Calculate the keys for this block. */
> +	xfs_btree_get_keys(cur, block, &block_keys);
> +
> +	/* Obtain the parent's copy of the keys for this block. */
> +	parent_block = xfs_btree_get_block(cur, level + 1, &bp);
> +	parent_keys = xfs_btree_key_addr(cur, cur->bc_ptrs[level + 1],
> +			parent_block);
> +
> +	if (cur->bc_ops->diff_two_keys(cur, &block_keys, parent_keys) != 0)
> +		xfs_scrub_btree_set_corrupt(bs->sc, cur, 1);
> +
> +	if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
> +		return;
> +
> +	/* Get high keys */
> +	high_bk = xfs_btree_high_key_from_key(cur, &block_keys);
> +	high_pk = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level + 1],
> +			parent_block);
> +
> +	if (cur->bc_ops->diff_two_keys(cur, high_bk, high_pk) != 0)
> +		xfs_scrub_btree_set_corrupt(bs->sc, cur, 1);
> +}
> +
> +/*
>   * Visit all nodes and leaves of a btree.  Check that all pointers and
>   * records are in order, that the keys reflect the records, and use a callback
>   * so that the caller can verify individual records.
> @@ -418,6 +462,7 @@ xfs_scrub_btree(
>  			/* End of leaf, pop back towards the root. */
>  			if (cur->bc_ptrs[level] >
>  			    be16_to_cpu(block->bb_numrecs)) {
> +				xfs_scrub_btree_block_keys(&bs, level, block);
>  				if (level < cur->bc_nlevels - 1)
>  					cur->bc_ptrs[level + 1]++;
>  				level++;
> @@ -442,6 +487,7 @@ xfs_scrub_btree(
>  
>  		/* End of node, pop back towards the root. */
>  		if (cur->bc_ptrs[level] > be16_to_cpu(block->bb_numrecs)) {
> +			xfs_scrub_btree_block_keys(&bs, level, block);
>  			if (level < cur->bc_nlevels - 1)
>  				cur->bc_ptrs[level + 1]++;
>  			level++;
> 
> --
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