VFS: Add shrink_submounts()
Allow a submount to be marked as being 'shrinkable' by means of the
vfsmount->mnt_flags, and then add a function 'shrink_submounts()' which
attempts to recursively unmount these submounts.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/mount.h b/include/linux/mount.h
index aff68c3..9b4e007 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -23,6 +23,8 @@
#define MNT_NOATIME 0x08
#define MNT_NODIRATIME 0x10
+#define MNT_SHRINKABLE 0x100
+
#define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */
#define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */
#define MNT_PNODE_MASK 0x3000 /* propogation flag mask */
@@ -84,6 +86,7 @@
int mnt_flags, struct list_head *fslist);
extern void mark_mounts_for_expiry(struct list_head *mounts);
+extern void shrink_submounts(struct vfsmount *mountpoint, struct list_head *mounts);
extern spinlock_t vfsmount_lock;
extern dev_t name_to_dev_t(char *name);