tree ba8bf30382d1891c7f540264b6229db1bc1eb797
parent 3b77f777b8f1c001b63e317c4ce317292ff0ff94
author James Bottomley <James.Bottomley@HansenPartnership.com> 1243426628 +0200
committer Jens Axboe <jens.axboe@oracle.com> 1243426628 +0200

block: fix oops with block tag queueing

commit e8939a50466fd963eb1ba9118c34b9ffb7ff6aa6
Author: Tejun Heo <tj@kernel.org>
Date:   Fri May 8 11:54:16 2009 +0900

    block: implement and enforce request peek/start/fetch

Added a BUG_ON(blk_queued_rq(req)) to the top of blk_finish_req().
Unfortunately, this checks whether req->queuelist is empty.  This list
is doing double duty both as the queue list and the tag list, so tagged
requests come in here with this not empty and boom (the tag list is
emptied by blk_queue_end_tag() lower down).

Fix this by moving the BUG_ON to below the end tag we also seem
vulnerable to this in blk_requeue_request() as well.  I think all uses
of blk_queued_rq() need auditing because the check is clearly wrong in
the tagged case.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>