[PATCH 20/24] xfs: cross-reference refcount btree during scrub

[Darrick J. Wong]

During metadata btree scrub, we should cross-reference with the
reference counts.

Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com>
---
 libxfs/xfs_refcount.c |   19 +++++++++++++++++++
 libxfs/xfs_refcount.h |    3 +++
 2 files changed, 22 insertions(+)


diff --git a/libxfs/xfs_refcount.c b/libxfs/xfs_refcount.c
index 7d3735f..2d747ba 100644
--- a/libxfs/xfs_refcount.c
+++ b/libxfs/xfs_refcount.c
@@ -1534,3 +1534,22 @@ xfs_refcount_free_cow_extent(
 	return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_FREE_COW,
 			fsb, len);
 }
+
+/* Is there a record covering a given extent? */
+int
+xfs_refcount_has_record(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len,
+	bool			*exists)
+{
+	union xfs_btree_irec	low;
+	union xfs_btree_irec	high;
+
+	memset(&low, 0, sizeof(low));
+	low.rc.rc_startblock = bno;
+	memset(&high, 0xFF, sizeof(high));
+	high.rc.rc_startblock = bno + len - 1;
+
+	return xfs_btree_has_record(cur, &low, &high, exists);
+}
diff --git a/libxfs/xfs_refcount.h b/libxfs/xfs_refcount.h
index 105c246..a00400f 100644
--- a/libxfs/xfs_refcount.h
+++ b/libxfs/xfs_refcount.h
@@ -64,4 +64,7 @@ extern int xfs_refcount_free_cow_extent(struct xfs_mount *mp,
 		struct xfs_defer_ops *dfops, xfs_fsblock_t fsb,
 		xfs_extlen_t len);
 
+extern int xfs_refcount_has_record(struct xfs_btree_cur *cur,
+		xfs_agblock_t bno, xfs_extlen_t len, bool *exists);
+
 #endif	/* __XFS_REFCOUNT_H__ */