vfs: umount_tree() might be called on subtree that had never made it
__mnt_make_shortterm() in there undoes the effect of __mnt_make_longterm()
we'd done back when we set ->mnt_ns non-NULL; it should not be done to
vfsmounts that had never gone through commit_tree() and friends. Kudos to
lczerner for catching that one...
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namespace.c b/fs/namespace.c
index 224aff1..1e4a5fe 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1074,8 +1074,9 @@
list_del_init(&p->mnt_expire);
list_del_init(&p->mnt_list);
__touch_mnt_namespace(p->mnt_ns);
+ if (p->mnt_ns)
+ __mnt_make_shortterm(p);
p->mnt_ns = NULL;
- __mnt_make_shortterm(p);
list_del_init(&p->mnt_child);
if (mnt_has_parent(p)) {
p->mnt_parent->mnt_ghosts++;