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

Brian Foster
2017-10-26T13:16:58Z

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++;