From 8f6205cd572fece673da0255d74843680f67f879 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 8 May 2009 11:53:59 +0900 Subject: ide: dequeue in-flight request ide generally has single request in flight and tracks it using hwif->rq and all state handlers follow the following convention. * ide_started is returned if the request is in flight. * ide_stopped is returned if the queue needs to be restarted. The request might or might not have been processed fully or partially. * hwif->rq is set to NULL, when an issued request completes. So, dequeueing model can be implemented by dequeueing after fetch, requeueing if hwif->rq isn't NULL on ide_stopped return and doing about the same thing on completion / port unlock paths. These changes can be made in ide-io proper. In addition to the above main changes, the following updates are necessary. * ide-cd shouldn't dequeue a request when issuing REQUEST SENSE for it as the request is already dequeued. * ide-atapi uses request queue as stack when issuing REQUEST SENSE to put the REQUEST SENSE in front of the failed request. This now needs to be done using requeueing. [ Impact: dequeue in-flight request ] Signed-off-by: Tejun Heo Cc: Bartlomiej Zolnierkiewicz Cc: Borislav Petkov Cc: Sergei Shtylyov Signed-off-by: Jens Axboe --- drivers/ide/ide-atapi.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/ide/ide-atapi.c') diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c index 792534db8f85..2874c3d703a9 100644 --- a/drivers/ide/ide-atapi.c +++ b/drivers/ide/ide-atapi.c @@ -246,6 +246,7 @@ EXPORT_SYMBOL_GPL(ide_queue_sense_rq); */ void ide_retry_pc(ide_drive_t *drive) { + struct request *failed_rq = drive->hwif->rq; struct request *sense_rq = &drive->sense_rq; struct ide_atapi_pc *pc = &drive->request_sense_pc; @@ -260,8 +261,17 @@ void ide_retry_pc(ide_drive_t *drive) if (drive->media == ide_tape) set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags); - if (ide_queue_sense_rq(drive, pc)) - ide_complete_rq(drive, -EIO, blk_rq_bytes(drive->hwif->rq)); + /* + * Push back the failed request and put request sense on top + * of it. The failed command will be retried after sense data + * is acquired. + */ + blk_requeue_request(failed_rq->q, failed_rq); + drive->hwif->rq = NULL; + if (ide_queue_sense_rq(drive, pc)) { + blkdev_dequeue_request(failed_rq); + ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq)); + } } EXPORT_SYMBOL_GPL(ide_retry_pc); -- cgit v1.2.3