[PATCH] dm: free minor after unlink gendisk

Minor number should be freed after del_gendisk().  Otherwise, there could
be a window where 2 registered gendisk has same minor number.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
[chrisw: backport to 2.6.15]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index e0b63d7f5704dab15719b3ba5b5f8bf27538f0df..3b7701a0386108e23460141d16638b57b05b64a9 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -812,14 +812,16 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent)
 
 static void free_dev(struct mapped_device *md)
 {
+       unsigned int minor = md->disk->first_minor;
+
        if (md->frozen_bdev) {
                thaw_bdev(md->frozen_bdev, NULL);
                bdput(md->frozen_bdev);
        }
-       free_minor(md->disk->first_minor);
        mempool_destroy(md->tio_pool);
        mempool_destroy(md->io_pool);
        del_gendisk(md->disk);
+       free_minor(minor);
        put_disk(md->disk);
        blk_put_queue(md->queue);
        kfree(md);