xfs: mask off the rtbitmap and summary inodes when metadir in use

Set the rtbitmap and summary file inumbers to NULLFSINO in the
superblock and make sure they're zeroed whenever we write the superblock
to disk, to mimic mkfs behavior.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Author: Darrick J. Wong

fs/xfs/libxfs/xfs_sb.c

@@ -655,6 +655,14 @@ xfs_validate_sb_common(
 void
 xfs_sb_quota_from_disk(struct xfs_sb *sbp)
 {
+	if (xfs_sb_is_v5(sbp) &&
+	    (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR)) {
+		sbp->sb_uquotino = NULLFSINO;
+		sbp->sb_gquotino = NULLFSINO;
+		sbp->sb_pquotino = NULLFSINO;
+		return;
+	}
+
 	/*
 	 * older mkfs doesn't initialize quota inodes to NULLFSINO. This
 	 * leads to in-core values having two different values for a quota
@@ -783,6 +791,8 @@ __xfs_sb_from_disk(
 		to->sb_metadirino = be64_to_cpu(from->sb_metadirino);
 		to->sb_rgcount = be32_to_cpu(from->sb_rgcount);
 		to->sb_rgextents = be32_to_cpu(from->sb_rgextents);
+		to->sb_rbmino = NULLFSINO;
+		to->sb_rsumino = NULLFSINO;
 	} else {
 		to->sb_metadirino = NULLFSINO;
 		to->sb_rgcount = 1;
@@ -805,6 +815,14 @@ xfs_sb_quota_to_disk(
 {
 	uint16_t	qflags = from->sb_qflags;
 
+	if (xfs_sb_is_v5(from) &&
+	    (from->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_METADIR)) {
+		to->sb_uquotino = cpu_to_be64(0);
+		to->sb_gquotino = cpu_to_be64(0);
+		to->sb_pquotino = cpu_to_be64(0);
+		return;
+	}
+
 	to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
 
 	/*
@@ -940,6 +958,8 @@ xfs_sb_to_disk(
 		to->sb_metadirino = cpu_to_be64(from->sb_metadirino);
 		to->sb_rgcount = cpu_to_be32(from->sb_rgcount);
 		to->sb_rgextents = cpu_to_be32(from->sb_rgextents);
+		to->sb_rbmino = cpu_to_be64(0);
+		to->sb_rsumino = cpu_to_be64(0);
 	}
 }