From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 04/10] block: drop custom queue draining used by scsi_transport_{iscsi|fc} Date: Mon, 4 Jun 2012 20:40:54 -0700 Message-ID: <1338867660-4689-5-git-send-email-tj@kernel.org> References: <1338867660-4689-1-git-send-email-tj@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1338867660-4689-1-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: ctalbott-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, rni-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, James Smart , hughd-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, Tejun Heo , akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, fengguang.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org List-Id: containers.vger.kernel.org iscsi_remove_host() uses bsg_remove_queue() which implements custom queue draining. fc_bsg_remove() open-codes mostly identical logic. The draining logic isn't correct in that blk_stop_queue() doesn't prevent new requests from being queued - it just stops processing, so nothing prevents new requests to be queued after the logic determines that the queue is drained. blk_cleanup_queue() now implements proper queue draining and these custom draining logics aren't necessary. Drop them and use bsg_unregister_queue() + blk_cleanup_queue() instead. Signed-off-by: Tejun Heo Reviewed-by: Mike Christie Acked-by: Vivek Goyal Cc: James Bottomley Cc: James Smart --- block/bsg-lib.c | 53 ----------------------------------- drivers/scsi/scsi_transport_fc.c | 38 ------------------------- drivers/scsi/scsi_transport_iscsi.c | 2 +- include/linux/bsg-lib.h | 1 - 4 files changed, 1 insertions(+), 93 deletions(-) diff --git a/block/bsg-lib.c b/block/bsg-lib.c index 7ad49c8..deee61f 100644 --- a/block/bsg-lib.c +++ b/block/bsg-lib.c @@ -243,56 +243,3 @@ int bsg_setup_queue(struct device *dev, struct request_queue *q, return 0; } EXPORT_SYMBOL_GPL(bsg_setup_queue); - -/** - * bsg_remove_queue - Deletes the bsg dev from the q - * @q: the request_queue that is to be torn down. - * - * Notes: - * Before unregistering the queue empty any requests that are blocked - */ -void bsg_remove_queue(struct request_queue *q) -{ - struct request *req; /* block request */ - int counts; /* totals for request_list count and starved */ - - if (!q) - return; - - /* Stop taking in new requests */ - spin_lock_irq(q->queue_lock); - blk_stop_queue(q); - - /* drain all requests in the queue */ - while (1) { - /* need the lock to fetch a request - * this may fetch the same reqeust as the previous pass - */ - req = blk_fetch_request(q); - /* save requests in use and starved */ - counts = q->rq.count[0] + q->rq.count[1] + - q->rq.starved[0] + q->rq.starved[1]; - spin_unlock_irq(q->queue_lock); - /* any requests still outstanding? */ - if (counts == 0) - break; - - /* This may be the same req as the previous iteration, - * always send the blk_end_request_all after a prefetch. - * It is not okay to not end the request because the - * prefetch started the request. - */ - if (req) { - /* return -ENXIO to indicate that this queue is - * going away - */ - req->errors = -ENXIO; - blk_end_request_all(req, -ENXIO); - } - - msleep(200); /* allow bsg to possibly finish */ - spin_lock_irq(q->queue_lock); - } - bsg_unregister_queue(q); -} -EXPORT_SYMBOL_GPL(bsg_remove_queue); diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index 5797604..a9617ad 100644 --- a/drivers/scsi/scsi_transport_fc.c +++ b/drivers/scsi/scsi_transport_fc.c @@ -4130,45 +4130,7 @@ fc_bsg_rportadd(struct Scsi_Host *shost, struct fc_rport *rport) static void fc_bsg_remove(struct request_queue *q) { - struct request *req; /* block request */ - int counts; /* totals for request_list count and starved */ - if (q) { - /* Stop taking in new requests */ - spin_lock_irq(q->queue_lock); - blk_stop_queue(q); - - /* drain all requests in the queue */ - while (1) { - /* need the lock to fetch a request - * this may fetch the same reqeust as the previous pass - */ - req = blk_fetch_request(q); - /* save requests in use and starved */ - counts = q->rq.count[0] + q->rq.count[1] + - q->rq.starved[0] + q->rq.starved[1]; - spin_unlock_irq(q->queue_lock); - /* any requests still outstanding? */ - if (counts == 0) - break; - - /* This may be the same req as the previous iteration, - * always send the blk_end_request_all after a prefetch. - * It is not okay to not end the request because the - * prefetch started the request. - */ - if (req) { - /* return -ENXIO to indicate that this queue is - * going away - */ - req->errors = -ENXIO; - blk_end_request_all(req, -ENXIO); - } - - msleep(200); /* allow bsg to possibly finish */ - spin_lock_irq(q->queue_lock); - } - bsg_unregister_queue(q); blk_cleanup_queue(q); } diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 1cf640e..c737a16 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -575,7 +575,7 @@ static int iscsi_remove_host(struct transport_container *tc, struct iscsi_cls_host *ihost = shost->shost_data; if (ihost->bsg_q) { - bsg_remove_queue(ihost->bsg_q); + bsg_unregister_queue(ihost->bsg_q); blk_cleanup_queue(ihost->bsg_q); } return 0; diff --git a/include/linux/bsg-lib.h b/include/linux/bsg-lib.h index f55ab8c..4d0fb3d 100644 --- a/include/linux/bsg-lib.h +++ b/include/linux/bsg-lib.h @@ -67,7 +67,6 @@ void bsg_job_done(struct bsg_job *job, int result, int bsg_setup_queue(struct device *dev, struct request_queue *q, char *name, bsg_job_fn *job_fn, int dd_job_size); void bsg_request_fn(struct request_queue *q); -void bsg_remove_queue(struct request_queue *q); void bsg_goose_queue(struct request_queue *q); #endif -- 1.7.7.3 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761456Ab2FEDlW (ORCPT ); Mon, 4 Jun 2012 23:41:22 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:49586 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752849Ab2FEDlT (ORCPT ); Mon, 4 Jun 2012 23:41:19 -0400 From: Tejun Heo To: axboe@kernel.dk, linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org Cc: vgoyal@redhat.com, ctalbott@google.com, rni@google.com, fengguang.wu@intel.com, hughd@google.com, akpm@linux-foundation.org, Tejun Heo , James Bottomley , James Smart Subject: [PATCH 04/10] block: drop custom queue draining used by scsi_transport_{iscsi|fc} Date: Mon, 4 Jun 2012 20:40:54 -0700 Message-Id: <1338867660-4689-5-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.7.3 In-Reply-To: <1338867660-4689-1-git-send-email-tj@kernel.org> References: <1338867660-4689-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org iscsi_remove_host() uses bsg_remove_queue() which implements custom queue draining. fc_bsg_remove() open-codes mostly identical logic. The draining logic isn't correct in that blk_stop_queue() doesn't prevent new requests from being queued - it just stops processing, so nothing prevents new requests to be queued after the logic determines that the queue is drained. blk_cleanup_queue() now implements proper queue draining and these custom draining logics aren't necessary. Drop them and use bsg_unregister_queue() + blk_cleanup_queue() instead. Signed-off-by: Tejun Heo Reviewed-by: Mike Christie Acked-by: Vivek Goyal Cc: James Bottomley Cc: James Smart --- block/bsg-lib.c | 53 ----------------------------------- drivers/scsi/scsi_transport_fc.c | 38 ------------------------- drivers/scsi/scsi_transport_iscsi.c | 2 +- include/linux/bsg-lib.h | 1 - 4 files changed, 1 insertions(+), 93 deletions(-) diff --git a/block/bsg-lib.c b/block/bsg-lib.c index 7ad49c8..deee61f 100644 --- a/block/bsg-lib.c +++ b/block/bsg-lib.c @@ -243,56 +243,3 @@ int bsg_setup_queue(struct device *dev, struct request_queue *q, return 0; } EXPORT_SYMBOL_GPL(bsg_setup_queue); - -/** - * bsg_remove_queue - Deletes the bsg dev from the q - * @q: the request_queue that is to be torn down. - * - * Notes: - * Before unregistering the queue empty any requests that are blocked - */ -void bsg_remove_queue(struct request_queue *q) -{ - struct request *req; /* block request */ - int counts; /* totals for request_list count and starved */ - - if (!q) - return; - - /* Stop taking in new requests */ - spin_lock_irq(q->queue_lock); - blk_stop_queue(q); - - /* drain all requests in the queue */ - while (1) { - /* need the lock to fetch a request - * this may fetch the same reqeust as the previous pass - */ - req = blk_fetch_request(q); - /* save requests in use and starved */ - counts = q->rq.count[0] + q->rq.count[1] + - q->rq.starved[0] + q->rq.starved[1]; - spin_unlock_irq(q->queue_lock); - /* any requests still outstanding? */ - if (counts == 0) - break; - - /* This may be the same req as the previous iteration, - * always send the blk_end_request_all after a prefetch. - * It is not okay to not end the request because the - * prefetch started the request. - */ - if (req) { - /* return -ENXIO to indicate that this queue is - * going away - */ - req->errors = -ENXIO; - blk_end_request_all(req, -ENXIO); - } - - msleep(200); /* allow bsg to possibly finish */ - spin_lock_irq(q->queue_lock); - } - bsg_unregister_queue(q); -} -EXPORT_SYMBOL_GPL(bsg_remove_queue); diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index 5797604..a9617ad 100644 --- a/drivers/scsi/scsi_transport_fc.c +++ b/drivers/scsi/scsi_transport_fc.c @@ -4130,45 +4130,7 @@ fc_bsg_rportadd(struct Scsi_Host *shost, struct fc_rport *rport) static void fc_bsg_remove(struct request_queue *q) { - struct request *req; /* block request */ - int counts; /* totals for request_list count and starved */ - if (q) { - /* Stop taking in new requests */ - spin_lock_irq(q->queue_lock); - blk_stop_queue(q); - - /* drain all requests in the queue */ - while (1) { - /* need the lock to fetch a request - * this may fetch the same reqeust as the previous pass - */ - req = blk_fetch_request(q); - /* save requests in use and starved */ - counts = q->rq.count[0] + q->rq.count[1] + - q->rq.starved[0] + q->rq.starved[1]; - spin_unlock_irq(q->queue_lock); - /* any requests still outstanding? */ - if (counts == 0) - break; - - /* This may be the same req as the previous iteration, - * always send the blk_end_request_all after a prefetch. - * It is not okay to not end the request because the - * prefetch started the request. - */ - if (req) { - /* return -ENXIO to indicate that this queue is - * going away - */ - req->errors = -ENXIO; - blk_end_request_all(req, -ENXIO); - } - - msleep(200); /* allow bsg to possibly finish */ - spin_lock_irq(q->queue_lock); - } - bsg_unregister_queue(q); blk_cleanup_queue(q); } diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 1cf640e..c737a16 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -575,7 +575,7 @@ static int iscsi_remove_host(struct transport_container *tc, struct iscsi_cls_host *ihost = shost->shost_data; if (ihost->bsg_q) { - bsg_remove_queue(ihost->bsg_q); + bsg_unregister_queue(ihost->bsg_q); blk_cleanup_queue(ihost->bsg_q); } return 0; diff --git a/include/linux/bsg-lib.h b/include/linux/bsg-lib.h index f55ab8c..4d0fb3d 100644 --- a/include/linux/bsg-lib.h +++ b/include/linux/bsg-lib.h @@ -67,7 +67,6 @@ void bsg_job_done(struct bsg_job *job, int result, int bsg_setup_queue(struct device *dev, struct request_queue *q, char *name, bsg_job_fn *job_fn, int dd_job_size); void bsg_request_fn(struct request_queue *q); -void bsg_remove_queue(struct request_queue *q); void bsg_goose_queue(struct request_queue *q); #endif -- 1.7.7.3