xfs: online checking of the free rt extent countscrub-fixes_2020-10-26

Teach the summary count checker to count the number of free realtime
extents and compare that to the superblock copy.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

2 files changed, 51 insertions, 0 deletions

diff --git a/fs/xfs/scrub/fscounters.c b/fs/xfs/scrub/fscounters.c
index ec2064ed3c30..e9114c4a62b4 100644
--- a/fs/xfs/scrub/fscounters.c
+++ b/fs/xfs/scrub/fscounters.c
@@ -13,6 +13,8 @@
 #include "xfs_alloc.h"
 #include "xfs_ialloc.h"
 #include "xfs_health.h"
+#include "xfs_rtalloc.h"
+#include "xfs_inode.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
@@ -240,6 +242,49 @@ retry:
 	return 0;
 }
 
+static int
+xchk_fscount_add_frextent(
+	struct xfs_trans	*tp,
+	struct xfs_rtalloc_rec	*rec,
+	void			*priv)
+{
+	struct xchk_fscounters	*fsc = priv;
+
+	fsc->frextents += rec->ar_extcount;
+	return 0;
+}
+
+/*
+ * Calculate what the superblock free realtime extent count should be given the
+ * realtime bitmap.
+ */
+STATIC int
+xchk_fscount_check_frextents(
+	struct xfs_scrub	*sc,
+	struct xchk_fscounters	*fsc)
+{
+	struct xfs_mount	*mp = sc->mp;
+	int			error;
+
+	if (!xfs_sb_version_hasrealtime(&mp->m_sb))
+		return 0;
+
+	fsc->frextents = 0;
+	xfs_ilock(sc->mp->m_rbmip, XFS_ILOCK_EXCL);
+	error = xfs_rtalloc_query_all(sc->tp, xchk_fscount_add_frextent, fsc);
+	if (error)
+		goto out_unlock;
+
+	spin_lock(&mp->m_sb_lock);
+	if (fsc->frextents != mp->m_sb.sb_frextents)
+		xchk_set_corrupt(sc);
+	spin_unlock(&mp->m_sb_lock);
+
+out_unlock:
+	xfs_iunlock(sc->mp->m_rbmip, XFS_ILOCK_EXCL);
+	return error;
+}
+
 /*
  * Is the @counter reasonably close to the @expected value?
  *
@@ -351,5 +396,10 @@ xchk_fscounters(
 			fsc->fdblocks))
 		xchk_set_corrupt(sc);
 
+	/* Check the free extents counter for rt volumes. */
+	error = xchk_fscount_check_frextents(sc, fsc);
+	if (!xchk_process_error(sc, 0, XFS_SB_BLOCK(mp), &error))
+		return error;
+
 	return 0;
 }
diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index ad1ceb44a628..5ad442c166e8 100644
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -157,6 +157,7 @@ struct xchk_fscounters {
 	uint64_t		icount;
 	uint64_t		ifree;
 	uint64_t		fdblocks;
+	uint64_t		frextents;
 	unsigned long long	icount_min;
 	unsigned long long	icount_max;
 };