mnt: Add MNT_UMOUNT flag
In some instances it is necessary to know if the the unmounting
process has begun on a mount. Add MNT_UMOUNT to make that reliably
testable.
This fix gets used in fixing locked mounts in MNT_DETACH
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/fs/namespace.c b/fs/namespace.c
index 54cbef1..d170814 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1331,8 +1331,10 @@
struct mount *p;
/* Gather the mounts to umount */
- for (p = mnt; p; p = next_mnt(p, mnt))
+ for (p = mnt; p; p = next_mnt(p, mnt)) {
+ p->mnt.mnt_flags |= MNT_UMOUNT;
list_move(&p->mnt_list, &tmp_list);
+ }
/* Hide the mounts from lookup_mnt and mnt_mounts */
list_for_each_entry(p, &tmp_list, mnt_list) {
diff --git a/fs/pnode.c b/fs/pnode.c
index bf012af..ac3aa0d 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -384,6 +384,7 @@
if (child && list_empty(&child->mnt_mounts)) {
list_del_init(&child->mnt_child);
hlist_del_init_rcu(&child->mnt_hash);
+ child->mnt.mnt_flags |= MNT_UMOUNT;
list_move_tail(&child->mnt_list, &mnt->mnt_list);
}
}
diff --git a/include/linux/mount.h b/include/linux/mount.h
index c2c561d..564beee 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -61,6 +61,7 @@
#define MNT_DOOMED 0x1000000
#define MNT_SYNC_UMOUNT 0x2000000
#define MNT_MARKED 0x4000000
+#define MNT_UMOUNT 0x8000000
struct vfsmount {
struct dentry *mnt_root; /* root of the mounted tree */