[PATCH block#for-2.6.31] block: fix a possible oops on elv_abort_queue()

[PATCH block#for-2.6.31] block: fix a possible oops on elv_abort_queue()

[Kiyoshi Ueda]

Hi Jens,

I found one more mis-conversion to the 'request is always dequeued
when completing' model in elv_abort_queue() during code inspection.
Although I haven't hit any problem caused by this mis-conversion yet
and just done compile/boot test, please apply if you have no problem.


Request must be dequeued when it completes.
However, elv_abort_queue() completes requests without dequeueing.
This will cause oops in the __blk_end_request_all().
This patch fixes the oops.

Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
---
 block/elevator.c |    5 +++++
 1 file changed, 5 insertions(+)

Index: linux-2.6-block/block/elevator.c
===================================================================
--- linux-2.6-block.orig/block/elevator.c
+++ linux-2.6-block/block/elevator.c
@@ -813,6 +813,11 @@ void elv_abort_queue(struct request_queu
 		rq = list_entry_rq(q->queue_head.next);
 		rq->cmd_flags |= REQ_QUIET;
 		trace_block_rq_abort(q, rq);
+		/*
+		 * Mark this request as started so we don't trigger
+		 * any debug logic in the end I/O path.
+		 */
+		blk_start_request(rq);
 		__blk_end_request_all(rq, -EIO);
 	}
 }

Re: [PATCH block#for-2.6.31] block: fix a possible oops on elv_abort_queue()

[Jens Axboe]

On Tue, Jun 02 2009, Kiyoshi Ueda wrote:
> Hi Jens,
> 
> I found one more mis-conversion to the 'request is always dequeued
> when completing' model in elv_abort_queue() during code inspection.
> Although I haven't hit any problem caused by this mis-conversion yet
> and just done compile/boot test, please apply if you have no problem.
> 
> 
> Request must be dequeued when it completes.
> However, elv_abort_queue() completes requests without dequeueing.
> This will cause oops in the __blk_end_request_all().
> This patch fixes the oops.

Thanks, applied!

> Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
> Cc: Jens Axboe <jens.axboe@oracle.com>
> ---
>  block/elevator.c |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> Index: linux-2.6-block/block/elevator.c
> ===================================================================
> --- linux-2.6-block.orig/block/elevator.c
> +++ linux-2.6-block/block/elevator.c
> @@ -813,6 +813,11 @@ void elv_abort_queue(struct request_queu
>  		rq = list_entry_rq(q->queue_head.next);
>  		rq->cmd_flags |= REQ_QUIET;
>  		trace_block_rq_abort(q, rq);
> +		/*
> +		 * Mark this request as started so we don't trigger
> +		 * any debug logic in the end I/O path.
> +		 */
> +		blk_start_request(rq);
>  		__blk_end_request_all(rq, -EIO);
>  	}
>  }

-- 
Jens Axboe