Commit 2bea8df0 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: always scrub record/key order of interior records 



In commit d47fef93, we removed the firstrec and firstkey fields of
struct xchk_btree because Christoph thought they were unnecessary
because we could use the record index in the btree cursor.  This is
incorrect because bc_ptrs (now bc_levels[].ptr) tracks the cursor
position within a specific btree block, not within the entire level.

The end result is that scrub no longer detects situations where the
rightmost record of a block is identical to the leftmost record of that
block's right sibling.  Fix this regression by reintroducing record
validity booleans so that order checking skips *only* the leftmost
record/key in each level.

Fixes: d47fef93 ("xfs: don't track firstrec/firstkey separately in xchk_btree")
Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
parent c99f99fa

fs/xfs/scrub/btree.c

+8 −6
Original line number Diff line number Diff line
@@ -151,11 +151,12 @@ xchk_btree_rec( 


	trace_xchk_btree_rec(bs->sc, cur, 0);



	/* If this isn't the first record, are they in order? */

	if (cur->bc_levels[0].ptr > 1 &&

	/* Are all records across all record blocks in order? */

	if (bs->lastrec_valid &&

	    !cur->bc_ops->recs_inorder(cur, &bs->lastrec, rec))

		xchk_btree_set_corrupt(bs->sc, cur, 0);

	memcpy(&bs->lastrec, rec, cur->bc_ops->rec_len);

	bs->lastrec_valid = true;



	if (cur->bc_nlevels == 1)

		return;
@@ -198,11 +199,12 @@ xchk_btree_key( 


	trace_xchk_btree_key(bs->sc, cur, level);



	/* If this isn't the first key, are they in order? */

	if (cur->bc_levels[level].ptr > 1 &&

	    !cur->bc_ops->keys_inorder(cur, &bs->lastkey[level - 1], key))

	/* Are all low keys across all node blocks in order? */

	if (bs->lastkey[level - 1].valid &&

	    !cur->bc_ops->keys_inorder(cur, &bs->lastkey[level - 1].key, key))

		xchk_btree_set_corrupt(bs->sc, cur, level);

	memcpy(&bs->lastkey[level - 1], key, cur->bc_ops->key_len);

	memcpy(&bs->lastkey[level - 1].key, key, cur->bc_ops->key_len);

	bs->lastkey[level - 1].valid = true;



	if (level + 1 >= cur->bc_nlevels)

		return;

fs/xfs/scrub/btree.h

+7 −1
Original line number Diff line number Diff line
@@ -31,6 +31,11 @@ typedef int (*xchk_btree_rec_fn)( 
	struct xchk_btree		*bs,

	const union xfs_btree_rec	*rec);



struct xchk_btree_key {

	union xfs_btree_key		key;

	bool				valid;

};



struct xchk_btree {

	/* caller-provided scrub state */

	struct xfs_scrub		*sc;
@@ -40,11 +45,12 @@ struct xchk_btree { 
	void				*private;



	/* internal scrub state */

	bool				lastrec_valid;

	union xfs_btree_rec		lastrec;

	struct list_head		to_check;



	/* this element must come last! */

	union xfs_btree_key		lastkey[];

	struct xchk_btree_key		lastkey[];

};



/*