Commit 7596824e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 

Pull vfs fixes from Al Viro:
 "A couple of fixes; one for automount/lazy umount race, another a
  classic "we don't protect the refcount transition to zero with the
  lock that protects looking for object in hash" kind of crap in lockd."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  close the race in nlmsvc_free_block()
  do_add_mount()/umount -l races
parents 97956605 c5aa1e55

fs/lockd/svclock.c

+1 −2
Original line number Diff line number Diff line
@@ -289,7 +289,6 @@ static void nlmsvc_free_block(struct kref *kref) 
	dprintk("lockd: freeing block %p...\n", block);



	/* Remove block from file's list of blocks */

	mutex_lock(&file->f_mutex);

	list_del_init(&block->b_flist);

	mutex_unlock(&file->f_mutex);
@@ -303,7 +302,7 @@ static void nlmsvc_free_block(struct kref *kref) 
static void nlmsvc_release_block(struct nlm_block *block)

{

	if (block != NULL)

		kref_put(&block->b_count, nlmsvc_free_block);

		kref_put_mutex(&block->b_count, nlmsvc_free_block, &block->b_file->f_mutex);

}



/*

fs/namespace.c

+8 −2
Original line number Diff line number Diff line
@@ -1886,8 +1886,14 @@ static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags) 
		return err;



	err = -EINVAL;

	if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(real_mount(path->mnt)))

	if (unlikely(!check_mnt(real_mount(path->mnt)))) {

		/* that's acceptable only for automounts done in private ns */

		if (!(mnt_flags & MNT_SHRINKABLE))

			goto unlock;

		/* ... and for those we'd better have mountpoint still alive */

		if (!real_mount(path->mnt)->mnt_ns)

			goto unlock;

	}



	/* Refuse the same filesystem on the same mount point */

	err = -EBUSY;

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