get rid of propagate_umount() mistakenly treating slaves as busy.
authorAl Viro <viro@zeniv.linux.org.uk>
Mon, 18 Aug 2014 19:09:26 +0000 (15:09 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 17 Sep 2014 16:19:22 +0000 (09:19 -0700)
commit 88b368f27a094277143d8ecd5a056116f6a41520 upstream.

The check in __propagate_umount() ("has somebody explicitly mounted
something on that slave?") is done *before* taking the already doomed
victims out of the child lists.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fs/namespace.c
fs/pnode.c

index 9954f60..7af0433 100644 (file)
@@ -1253,6 +1253,9 @@ void umount_tree(struct mount *mnt, int how)
                hlist_add_head(&p->mnt_hash, &tmp_list);
        }
 
+       hlist_for_each_entry(p, &tmp_list, mnt_hash)
+               list_del_init(&p->mnt_child);
+
        if (how)
                propagate_umount(&tmp_list);
 
@@ -1263,7 +1266,6 @@ void umount_tree(struct mount *mnt, int how)
                p->mnt_ns = NULL;
                if (how < 2)
                        p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;
-               list_del_init(&p->mnt_child);
                if (mnt_has_parent(p)) {
                        put_mountpoint(p->mnt_mp);
                        /* move the reference to mountpoint into ->mnt_ex_mountpoint */
index a364a70..b7f8310 100644 (file)
@@ -381,6 +381,7 @@ static void __propagate_umount(struct mount *mnt)
                 * other children
                 */
                if (child && list_empty(&child->mnt_mounts)) {
+                       list_del_init(&child->mnt_child);
                        hlist_del_init_rcu(&child->mnt_hash);
                        hlist_add_before_rcu(&child->mnt_hash, &mnt->mnt_hash);
                }