[PATCH 40/43] xfs: repair inodes that have a refcount btree in the data fork

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

Plumb knowledge of refcount btrees into the inode core repair code.

Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
 fs/xfs/scrub/inode_repair.c |   36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)


diff --git a/fs/xfs/scrub/inode_repair.c b/fs/xfs/scrub/inode_repair.c
index 701baee144a66e..2f641b6d663eb2 100644
--- a/fs/xfs/scrub/inode_repair.c
+++ b/fs/xfs/scrub/inode_repair.c
@@ -40,6 +40,7 @@
 #include "xfs_symlink_remote.h"
 #include "xfs_rtgroup.h"
 #include "xfs_rtrmap_btree.h"
+#include "xfs_rtrefcount_btree.h"
 #include "scrub/xfs_scrub.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
@@ -970,6 +971,34 @@ xrep_dinode_bad_rtrmapbt_fork(
 	return false;
 }
 
+/* Return true if this refcount-format ifork looks like garbage. */
+STATIC bool
+xrep_dinode_bad_rtrefcountbt_fork(
+	struct xfs_scrub	*sc,
+	struct xfs_dinode	*dip,
+	unsigned int		dfork_size)
+{
+	struct xfs_rtrefcount_root *dfp;
+	unsigned int		nrecs;
+	unsigned int		level;
+
+	if (dfork_size < sizeof(struct xfs_rtrefcount_root))
+		return true;
+
+	dfp = XFS_DFORK_PTR(dip, XFS_DATA_FORK);
+	nrecs = be16_to_cpu(dfp->bb_numrecs);
+	level = be16_to_cpu(dfp->bb_level);
+
+	if (level > sc->mp->m_rtrefc_maxlevels)
+		return true;
+	if (xfs_rtrefcount_droot_space_calc(level, nrecs) > dfork_size)
+		return true;
+	if (level > 0 && nrecs == 0)
+		return true;
+
+	return false;
+}
+
 /* Check a metadata-btree fork. */
 STATIC bool
 xrep_dinode_bad_metabt_fork(
@@ -984,6 +1013,8 @@ xrep_dinode_bad_metabt_fork(
 	switch (be16_to_cpu(dip->di_metatype)) {
 	case XFS_METAFILE_RTRMAP:
 		return xrep_dinode_bad_rtrmapbt_fork(sc, dip, dfork_size);
+	case XFS_METAFILE_RTREFCOUNT:
+		return xrep_dinode_bad_rtrefcountbt_fork(sc, dip, dfork_size);
 	default:
 		return true;
 	}
@@ -1249,6 +1280,7 @@ xrep_dinode_ensure_forkoff(
 {
 	struct xfs_bmdr_block	*bmdr;
 	struct xfs_rtrmap_root	*rmdr;
+	struct xfs_rtrefcount_root *rcdr;
 	struct xfs_scrub	*sc = ri->sc;
 	xfs_extnum_t		attr_extents, data_extents;
 	size_t			bmdr_minsz = xfs_bmdr_space_calc(1);
@@ -1361,6 +1393,10 @@ xrep_dinode_ensure_forkoff(
 			rmdr = XFS_DFORK_PTR(dip, XFS_DATA_FORK);
 			dfork_min = xfs_rtrmap_broot_space(sc->mp, rmdr);
 			break;
+		case XFS_METAFILE_RTREFCOUNT:
+			rcdr = XFS_DFORK_PTR(dip, XFS_DATA_FORK);
+			dfork_min = xfs_rtrefcount_broot_space(sc->mp, rcdr);
+			break;
 		default:
 			dfork_min = 0;
 			break;