diff options
| author | Bart Van Assche <bvanassche@acm.org> | 2014-02-21 02:20:56 +0400 |
|---|---|---|
| committer | James Bottomley <JBottomley@Parallels.com> | 2014-03-15 21:19:25 +0400 |
| commit | 613be1f626e602c6744101a003e8fc5c180e1af9 (patch) | |
| tree | 4c78a6ed1be7b817fdb7a233dd1d346e786f2f31 /drivers/scsi | |
| parent | 0479633686d370303e3430256ace4bd5f7f138dc (diff) | |
| download | linux-613be1f626e602c6744101a003e8fc5c180e1af9.tar.xz | |
[SCSI] remove a useless get/put_device pair in scsi_request_fn
SCSI devices may only be removed by calling scsi_remove_device().
That function must invoke blk_cleanup_queue() before the final put
of sdev->sdev_gendev. Since blk_cleanup_queue() waits for the
block queue to drain and then tears it down, scsi_request_fn cannot
be active anymore after blk_cleanup_queue() has returned and hence
the get_device()/put_device() pair in scsi_request_fn is unnecessary.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 14 |
1 files changed, 3 insertions, 11 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 007e979fa437..f8a8765a7979 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1565,16 +1565,14 @@ static void scsi_softirq_done(struct request *rq) * Lock status: IO request lock assumed to be held when called. */ static void scsi_request_fn(struct request_queue *q) + __releases(q->queue_lock) + __acquires(q->queue_lock) { struct scsi_device *sdev = q->queuedata; struct Scsi_Host *shost; struct scsi_cmnd *cmd; struct request *req; - if(!get_device(&sdev->sdev_gendev)) - /* We must be tearing the block queue down already */ - return; - /* * To start with, we keep looping until the queue is empty, or until * the host is no longer able to accept any more requests. @@ -1663,7 +1661,7 @@ static void scsi_request_fn(struct request_queue *q) goto out_delay; } - goto out; + return; not_ready: spin_unlock_irq(shost->host_lock); @@ -1682,12 +1680,6 @@ static void scsi_request_fn(struct request_queue *q) out_delay: if (sdev->device_busy == 0) blk_delay_queue(q, SCSI_QUEUE_DELAY); -out: - /* must be careful here...if we trigger the ->remove() function - * we cannot be holding the q lock */ - spin_unlock_irq(q->queue_lock); - put_device(&sdev->sdev_gendev); - spin_lock_irq(q->queue_lock); } u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) |