[ 25/47] vfs: umount_tree() might be called on subtree that had never made it

From: Greg KH
Date: Thu Jun 07 2012 - 00:24:17 EST


3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit 63d37a84ab6004c235314ffd7a76c5eb28c2fae0 upstream.

__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...

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/namespace.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1244,8 +1244,9 @@ void umount_tree(struct vfsmount *mnt, i
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 (p->mnt_parent != p) {
p->mnt_parent->mnt_ghosts++;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/