On Tue, Dec 16 2008, James Bottomley wrote:
> We can eliminate the SCSI command timed out check entirely if the block
> layer does this for us. The way to do this in block is to check how
> long the request has been outstanding if a requeue is requested and
> ending it if we've gone over retries * timeout.
>
> This will also eliminate many cases in SCSI where we evade the command
> timeout for various reasons (like initial success converted to requeue)
>
> James
>
> ---
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index c36aa98..d32af31 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -926,6 +926,8 @@ EXPORT_SYMBOL(blk_start_queueing);
> */
> void blk_requeue_request(struct request_queue *q, struct request *rq)
> {
> + unsigned long wait_for = (rq->retries + 1) * rq->timeout;
> +
> blk_delete_timer(rq);
> blk_clear_rq_complete(rq);
> blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
> @@ -933,7 +935,17 @@ void blk_requeue_request(struct request_queue *q, struct request *rq)
> if (blk_rq_tagged(rq))
> blk_queue_end_tag(q, rq);
>
> - elv_requeue_request(q, rq);
> + if (time_before(rq->start_time + wait_for, jiffies)) {
I prefer time_after(), reads better.
> + int bytes = (rq->hard_nr_sectors << 9);
> +
> + printk(KERN_ERR "%s: timing out command, waited %lus\n",
> + rq->rq_disk ? rq->rq_disk->disk_name : "?",
> + wait_for/HZ);
> + if (blk_pc_request(rq))
> + bytes = rq->data_len;
> + blk_end_request(rq, -EIO, bytes);
You can just do
blk_end_request(rq, -EIO, blk_rq_bytes(rq));
and get rid of the 'bytes' variable and type check.
> + } else
> + elv_requeue_request(q, rq);
> }
> EXPORT_SYMBOL(blk_requeue_request);
But I agree with the patch. Will you rediff, or shall I just apply with
the suggest changes?
--
Jens Axboe
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