[PATCH 19/23] xfs: Add the parent pointer support to the superblock version 5.

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

From: Allison Henderson <allison.henderson@xxxxxxxxxx>

Add the parent pointer superblock flag so that we can actually mount
filesystems with this feature enabled.

Signed-off-by: Mark Tinguely <tinguely@xxxxxxx>
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Signed-off-by: Allison Henderson <allison.henderson@xxxxxxxxxx>
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_format.h |    4 +++-
 fs/xfs/libxfs/xfs_fs.h     |    2 ++
 fs/xfs/libxfs/xfs_sb.c     |    4 ++++
 fs/xfs/xfs_super.c         |    4 ++++
 4 files changed, 13 insertions(+), 1 deletion(-)


diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index a823bba1f7d79..859062ab6c306 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -373,13 +373,15 @@ xfs_sb_has_ro_compat_feature(
 #define XFS_SB_FEAT_INCOMPAT_BIGTIME	(1 << 3)	/* large timestamps */
 #define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4)	/* needs xfs_repair */
 #define XFS_SB_FEAT_INCOMPAT_NREXT64	(1 << 5)	/* large extent counters */
+#define XFS_SB_FEAT_INCOMPAT_PARENT	(1 << 6)	/* parent pointers */
 #define XFS_SB_FEAT_INCOMPAT_ALL \
 		(XFS_SB_FEAT_INCOMPAT_FTYPE|	\
 		 XFS_SB_FEAT_INCOMPAT_SPINODES|	\
 		 XFS_SB_FEAT_INCOMPAT_META_UUID| \
 		 XFS_SB_FEAT_INCOMPAT_BIGTIME| \
 		 XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR| \
-		 XFS_SB_FEAT_INCOMPAT_NREXT64)
+		 XFS_SB_FEAT_INCOMPAT_NREXT64| \
+		 XFS_SB_FEAT_INCOMPAT_PARENT)
 
 #define XFS_SB_FEAT_INCOMPAT_UNKNOWN	~XFS_SB_FEAT_INCOMPAT_ALL
 static inline bool
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index 8ab8de8a6e632..e54938d5b928b 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -243,6 +243,8 @@ typedef struct xfs_fsop_resblks {
 /* file range exchange available to userspace */
 #define XFS_FSOP_GEOM_FLAGS_EXCHANGE_RANGE	(1 << 24)
 
+#define XFS_FSOP_GEOM_FLAGS_PARENT	(1U << 30) /* parent pointers */
+
 /*
  * Minimum and maximum sizes need for growth checks.
  *
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index c2d86faeee61b..22f5420adb3e5 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -176,6 +176,8 @@ xfs_sb_version_to_features(
 		features |= XFS_FEAT_NEEDSREPAIR;
 	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_NREXT64)
 		features |= XFS_FEAT_NREXT64;
+	if (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_PARENT)
+		features |= XFS_FEAT_PARENT;
 
 	return features;
 }
@@ -1251,6 +1253,8 @@ xfs_fs_geometry(
 		geo->flags |= XFS_FSOP_GEOM_FLAGS_BIGTIME;
 	if (xfs_has_inobtcounts(mp))
 		geo->flags |= XFS_FSOP_GEOM_FLAGS_INOBTCNT;
+	if (xfs_has_parent(mp))
+		geo->flags |= XFS_FSOP_GEOM_FLAGS_PARENT;
 	if (xfs_has_sector(mp)) {
 		geo->flags |= XFS_FSOP_GEOM_FLAGS_SECTOR;
 		geo->logsectsize = sbp->sb_logsectsize;
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 15b59c37e0ed1..ecf837f84ec0c 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1741,6 +1741,10 @@ xfs_fs_fill_super(
 		goto out_filestream_unmount;
 	}
 
+	if (xfs_has_parent(mp))
+		xfs_warn(mp,
+	"EXPERIMENTAL parent pointer feature enabled. Use at your own risk!");
+
 	error = xfs_mountfs(mp);
 	if (error)
 		goto out_filestream_unmount;