From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: [PATCH v7 2/9] Remove get_device() / put_device() pair from scsi_request_fn() Date: Thu, 06 Dec 2012 16:53:51 +0100 Message-ID: <50C0BF8F.3060401@acm.org> References: <50C0BEEE.4040907@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from georges.telenet-ops.be ([195.130.137.68]:48650 "EHLO georges.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1424105Ab2LFPxx (ORCPT ); Thu, 6 Dec 2012 10:53:53 -0500 In-Reply-To: <50C0BEEE.4040907@acm.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org Cc: linux-scsi , James Bottomley , Mike Christie , Tejun Heo , Chanho Min , Jens Axboe Now that all scsi_request_fn() callers hold a reference on the SCSI device that function is invoked for and since blk_cleanup_queue() waits until scsi_request_fn() has finished it is safe to remove the get_device() / put_device() pair from scsi_request_fn(). Signed-off-by: Bart Van Assche Acked-by: Tejun Heo Cc: James Bottomley Cc: Mike Christie Cc: Jens Axboe --- drivers/scsi/scsi_lib.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 5c67339..db4836bc 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1529,16 +1529,14 @@ 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. @@ -1627,7 +1625,7 @@ static void scsi_request_fn(struct request_queue *q) goto out_delay; } - goto out; + return; not_ready: spin_unlock_irq(shost->host_lock); @@ -1646,12 +1644,6 @@ 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) -- 1.7.10.4