[PATCH 33/39] xfs: repair rmap btree inodes

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

From: Darrick J. Wong <djwong@xxxxxxxxxx>

Teach the inode repair code how to deal with realtime rmap btree inodes
that won't load properly.  This is most likely moot since the filesystem
generally won't mount without the rtrmapbt inodes being usable, but
we'll add this for completeness.

Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
 fs/xfs/scrub/inode_repair.c |   46 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)


diff --git a/fs/xfs/scrub/inode_repair.c b/fs/xfs/scrub/inode_repair.c
index 45ad78d1e5404..f4f6ed6ef5120 100644
--- a/fs/xfs/scrub/inode_repair.c
+++ b/fs/xfs/scrub/inode_repair.c
@@ -895,6 +895,37 @@ xrep_dinode_bad_bmbt_fork(
 	return false;
 }
 
+/* Return true if this rmap-format ifork looks like garbage. */
+STATIC bool
+xrep_dinode_bad_rmapbt_fork(
+	struct xfs_scrub	*sc,
+	struct xfs_dinode	*dip,
+	unsigned int		dfork_size,
+	int			whichfork)
+{
+	struct xfs_rtrmap_root	*dfp;
+	unsigned int		nrecs;
+	unsigned int		level;
+
+	if (whichfork != XFS_DATA_FORK)
+		return true;
+	if (dfork_size < sizeof(struct xfs_rtrmap_root))
+		return true;
+
+	dfp = XFS_DFORK_PTR(dip, whichfork);
+	nrecs = be16_to_cpu(dfp->bb_numrecs);
+	level = be16_to_cpu(dfp->bb_level);
+
+	if (level > sc->mp->m_rtrmap_maxlevels)
+		return true;
+	if (xfs_rtrmap_droot_space_calc(level, nrecs) > dfork_size)
+		return true;
+	if (level > 0 && nrecs == 0)
+		return true;
+
+	return false;
+}
+
 /*
  * Check the data fork for things that will fail the ifork verifiers or the
  * ifork formatters.
@@ -975,6 +1006,11 @@ xrep_dinode_check_dfork(
 				XFS_DATA_FORK))
 			return true;
 		break;
+	case XFS_DINODE_FMT_RMAP:
+		if (xrep_dinode_bad_rmapbt_fork(sc, dip, dfork_size,
+				XFS_DATA_FORK))
+			return true;
+		break;
 	default:
 		return true;
 	}
@@ -1095,6 +1131,11 @@ xrep_dinode_check_afork(
 					XFS_ATTR_FORK))
 			return true;
 		break;
+	case XFS_DINODE_FMT_RMAP:
+		if (xrep_dinode_bad_rmapbt_fork(sc, dip, afork_size,
+				XFS_ATTR_FORK))
+			return true;
+		break;
 	default:
 		return true;
 	}
@@ -1142,6 +1183,7 @@ xrep_dinode_ensure_forkoff(
 	uint16_t		mode)
 {
 	struct xfs_bmdr_block	*bmdr;
+	struct xfs_rtrmap_root	*rmdr;
 	struct xfs_scrub	*sc = ri->sc;
 	xfs_extnum_t		attr_extents, data_extents;
 	size_t			bmdr_minsz = xfs_bmdr_space_calc(1);
@@ -1248,6 +1290,10 @@ xrep_dinode_ensure_forkoff(
 		bmdr = XFS_DFORK_PTR(dip, XFS_DATA_FORK);
 		dfork_min = xfs_bmap_broot_space(sc->mp, bmdr);
 		break;
+	case XFS_DINODE_FMT_RMAP:
+		rmdr = XFS_DFORK_PTR(dip, XFS_DATA_FORK);
+		dfork_min = xfs_rtrmap_broot_space(sc->mp, rmdr);
+		break;
 	default:
 		dfork_min = 0;
 		break;