Commit 88b368f2 authored Aug 18, 2014 by Al Viro

get rid of propagate_umount() mistakenly treating slaves as busy.



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.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent 52addcf9

fs/namespace.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -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 */

fs/pnode.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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);
		}