Commit 15f9a3f3 authored by Al Viro's avatar Al Viro
Browse files

don't drop newmnt on error in do_add_mount() 



That gets rid of the kludge in finish_automount() - we need
to keep refcount on the vfsmount as-is until we evict it from
expiry list.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 19a167af

fs/namespace.c

+5 −11
Original line number Diff line number Diff line
@@ -1880,6 +1880,7 @@ static int do_new_mount(struct path *path, char *type, int flags, 
			int mnt_flags, char *name, void *data)

{

	struct vfsmount *mnt;

	int err;



	if (!type)

		return -EINVAL;
@@ -1892,7 +1893,10 @@ static int do_new_mount(struct path *path, char *type, int flags, 
	if (IS_ERR(mnt))

		return PTR_ERR(mnt);



	return do_add_mount(mnt, path, mnt_flags);

	err = do_add_mount(mnt, path, mnt_flags);

	if (err)

		mntput(mnt);

	return err;

}



int finish_automount(struct vfsmount *m, struct path *path)
@@ -1911,26 +1915,17 @@ int finish_automount(struct vfsmount *m, struct path *path) 
		return -ELOOP;

	}



	/* We need to add the mountpoint to the parent.  The filesystem may

	 * have placed it on an expiry list, and so we need to make sure it

	 * won't be expired under us if do_add_mount() fails (do_add_mount()

	 * will eat a reference unconditionally).

	 */

	mntget(m);

	err = do_add_mount(m, path, path->mnt->mnt_flags | MNT_SHRINKABLE);

	if (err) {

		mnt_clear_expiry(m);

		mntput(m);

		mntput(m);

	} else {

		mntput(m);

	}

	return err;

}



/*

 * add a mount into a namespace's mount tree

 * - this unconditionally eats one of the caller's references to newmnt.

 */

int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)

{
@@ -1967,7 +1962,6 @@ int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags) 


unlock:

	up_write(&namespace_sem);

	mntput(newmnt);

	return err;

}