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author | Tejun Heo <tj@kernel.org> | 2009-05-08 11:53:59 +0900 |
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committer | Jens Axboe <jens.axboe@oracle.com> | 2009-05-11 09:52:14 +0200 |
commit | 8f6205cd572fece673da0255d74843680f67f879 (patch) | |
tree | bb89c1c5fe4436f5a0ec27f0d96074c7031a83ae /drivers/ide/ide-atapi.c | |
parent | 1011c1b9f2e45ce7c6e38888d2b83936aec38771 (diff) | |
download | kernel_samsung_tuna-8f6205cd572fece673da0255d74843680f67f879.zip kernel_samsung_tuna-8f6205cd572fece673da0255d74843680f67f879.tar.gz kernel_samsung_tuna-8f6205cd572fece673da0255d74843680f67f879.tar.bz2 |
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 <tj@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/ide/ide-atapi.c')
-rw-r--r-- | drivers/ide/ide-atapi.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c index 792534d..2874c3d 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); |