This lets userspace query whether a mountpoint was made MS_UNBINDABLE.
Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/statfs.c | 2 ++
include/linux/statfs.h | 1 +
2 files changed, 3 insertions(+)
diff --git a/fs/statfs.c b/fs/statfs.c
index 5b2a24f0f263..61b3063d3921 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -29,6 +29,8 @@ static int flags_by_mnt(int mnt_flags)
flags |= ST_NODIRATIME;
if (mnt_flags & MNT_RELATIME)
flags |= ST_RELATIME;
+ if (mnt_flags & MNT_UNBINDABLE)
+ flags |= ST_UNBINDABLE;
return flags;
}
diff --git a/include/linux/statfs.h b/include/linux/statfs.h
index b336c04e793c..e1b84d0388c1 100644
--- a/include/linux/statfs.h
+++ b/include/linux/statfs.h
@@ -40,5 +40,6 @@ struct kstatfs {
#define ST_NOATIME (1<<10) /* do not update access times */
#define ST_NODIRATIME (1<<11) /* do not update directory access times */
#define ST_RELATIME (1<<12) /* update atime relative to mtime/ctime */
+#define ST_UNBINDABLE (1<<17) /* change to unbindable */
#endif
--
2.17.0
