[PATCH 12/24] xfs: support scrubbing refcount btree

[Darrick J. Wong]

Plumb in the pieces necessary to check the refcount btree.  If rmap is
available, check the reference count by performing an interval query
against the rmapbt.

v2: Handle the case where the rmap records are not all at least the
length of the refcount extent.

Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com>
---
 libxfs/xfs_fs.h             |    3 ++-
 libxfs/xfs_refcount_btree.c |   33 +++++++++++++++++++++++++--------
 2 files changed, 27 insertions(+), 9 deletions(-)


diff --git a/libxfs/xfs_fs.h b/libxfs/xfs_fs.h
index bfc3940..45e0800 100644
--- a/libxfs/xfs_fs.h
+++ b/libxfs/xfs_fs.h
@@ -568,7 +568,8 @@ struct xfs_scrub_metadata {
 #define XFS_SCRUB_TYPE_INOBT	6	/* inode btree */
 #define XFS_SCRUB_TYPE_FINOBT	7	/* free inode btree */
 #define XFS_SCRUB_TYPE_RMAPBT	8	/* reverse mapping btree */
-#define XFS_SCRUB_TYPE_MAX	8
+#define XFS_SCRUB_TYPE_REFCNTBT	9	/* reference count btree */
+#define XFS_SCRUB_TYPE_MAX	9
 
 #define XFS_SCRUB_FLAGS_ALL	0x0	/* no flags yet */
 
diff --git a/libxfs/xfs_refcount_btree.c b/libxfs/xfs_refcount_btree.c
index d2dbdbd..7975abc 100644
--- a/libxfs/xfs_refcount_btree.c
+++ b/libxfs/xfs_refcount_btree.c
@@ -163,18 +163,26 @@ xfs_refcountbt_init_key_from_rec(
 	union xfs_btree_key	*key,
 	union xfs_btree_rec	*rec)
 {
-	ASSERT(rec->refc.rc_startblock != 0);
-
 	key->refc.rc_startblock = rec->refc.rc_startblock;
 }
 
 STATIC void
+xfs_refcountbt_init_high_key_from_rec(
+	union xfs_btree_key	*key,
+	union xfs_btree_rec	*rec)
+{
+	__u32			x;
+
+	x = be32_to_cpu(rec->refc.rc_startblock);
+	x += be32_to_cpu(rec->refc.rc_blockcount) - 1;
+	key->refc.rc_startblock = cpu_to_be32(x);
+}
+
+STATIC void
 xfs_refcountbt_init_rec_from_cur(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_rec	*rec)
 {
-	ASSERT(cur->bc_rec.rc.rc_startblock != 0);
-
 	rec->refc.rc_startblock = cpu_to_be32(cur->bc_rec.rc.rc_startblock);
 	rec->refc.rc_blockcount = cpu_to_be32(cur->bc_rec.rc.rc_blockcount);
 	rec->refc.rc_refcount = cpu_to_be32(cur->bc_rec.rc.rc_refcount);
@@ -204,6 +212,16 @@ xfs_refcountbt_key_diff(
 	return (__int64_t)be32_to_cpu(kp->rc_startblock) - rec->rc_startblock;
 }
 
+STATIC __int64_t
+xfs_refcountbt_diff_two_keys(
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_key	*k1,
+	union xfs_btree_key	*k2)
+{
+	return (__int64_t)be32_to_cpu(k1->refc.rc_startblock) -
+			  be32_to_cpu(k2->refc.rc_startblock);
+}
+
 STATIC bool
 xfs_refcountbt_verify(
 	struct xfs_buf		*bp)
@@ -266,7 +284,6 @@ const struct xfs_buf_ops xfs_refcountbt_buf_ops = {
 	.verify_write		= xfs_refcountbt_write_verify,
 };
 
-#if defined(DEBUG) || defined(XFS_WARN)
 STATIC int
 xfs_refcountbt_keys_inorder(
 	struct xfs_btree_cur	*cur,
@@ -295,13 +312,13 @@ xfs_refcountbt_recs_inorder(
 		b.rc_startblock = be32_to_cpu(r2->refc.rc_startblock);
 		b.rc_blockcount = be32_to_cpu(r2->refc.rc_blockcount);
 		b.rc_refcount = be32_to_cpu(r2->refc.rc_refcount);
+		a = a; b = b;
 		trace_xfs_refcount_rec_order_error(cur->bc_mp,
 				cur->bc_private.a.agno, &a, &b);
 	}
 
 	return ret;
 }
-#endif	/* DEBUG */
 
 static const struct xfs_btree_ops xfs_refcountbt_ops = {
 	.rec_len		= sizeof(struct xfs_refcount_rec),
@@ -314,14 +331,14 @@ static const struct xfs_btree_ops xfs_refcountbt_ops = {
 	.get_minrecs		= xfs_refcountbt_get_minrecs,
 	.get_maxrecs		= xfs_refcountbt_get_maxrecs,
 	.init_key_from_rec	= xfs_refcountbt_init_key_from_rec,
+	.init_high_key_from_rec	= xfs_refcountbt_init_high_key_from_rec,
 	.init_rec_from_cur	= xfs_refcountbt_init_rec_from_cur,
 	.init_ptr_from_cur	= xfs_refcountbt_init_ptr_from_cur,
 	.key_diff		= xfs_refcountbt_key_diff,
 	.buf_ops		= &xfs_refcountbt_buf_ops,
-#if defined(DEBUG) || defined(XFS_WARN)
+	.diff_two_keys		= xfs_refcountbt_diff_two_keys,
 	.keys_inorder		= xfs_refcountbt_keys_inorder,
 	.recs_inorder		= xfs_refcountbt_recs_inorder,
-#endif
 };
 
 /*