From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753436AbeBKJld (ORCPT ); Sun, 11 Feb 2018 04:41:33 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:33580 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752809AbeBKJjO (ORCPT ); Sun, 11 Feb 2018 04:39:14 -0500 From: Jianchao Wang To: keith.busch@intel.com, axboe@fb.com, hch@lst.de, sagi@grimberg.me Cc: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/9] nvme: change namespaces_mutext to namespaces_rwsem Date: Sun, 11 Feb 2018 17:38:34 +0800 Message-Id: <1518341920-1060-4-git-send-email-jianchao.w.wang@oracle.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1518341920-1060-1-git-send-email-jianchao.w.wang@oracle.com> References: <1518341920-1060-1-git-send-email-jianchao.w.wang@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8801 signatures=668668 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=638 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802110127 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org namespaces_mutext is used to synchronize the operations on ctrl namespaces list. Most of the time, it is a read operation. It is better to change it from mutex to rwsem. On the other hand, the namespaces mutex could introduce circular dependency easily. Signed-off-by: Jianchao Wang --- drivers/nvme/host/core.c | 64 +++++++++++++++++++++---------------------- drivers/nvme/host/multipath.c | 4 +-- drivers/nvme/host/nvme.h | 2 +- 3 files changed, 35 insertions(+), 35 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 7425124..176ba9e 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1120,14 +1120,14 @@ static void nvme_update_formats(struct nvme_ctrl *ctrl) struct nvme_ns *ns, *next; LIST_HEAD(rm_list); - mutex_lock(&ctrl->namespaces_mutex); + down_write(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) { if (ns->disk && nvme_revalidate_disk(ns->disk)) { list_del_init(&ns->list); list_add_tail(&ns->list, &rm_list); } } - mutex_unlock(&ctrl->namespaces_mutex); + up_write(&ctrl->namespaces_rwsem); list_for_each_entry_safe(ns, next, &rm_list, list) nvme_ns_remove(ns); @@ -2437,7 +2437,7 @@ static int nvme_dev_user_cmd(struct nvme_ctrl *ctrl, void __user *argp) struct nvme_ns *ns; int ret; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); if (list_empty(&ctrl->namespaces)) { ret = -ENOTTY; goto out_unlock; @@ -2454,14 +2454,14 @@ static int nvme_dev_user_cmd(struct nvme_ctrl *ctrl, void __user *argp) dev_warn(ctrl->device, "using deprecated NVME_IOCTL_IO_CMD ioctl on the char device!\n"); kref_get(&ns->kref); - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); ret = nvme_user_cmd(ctrl, ns, argp); nvme_put_ns(ns); return ret; out_unlock: - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); return ret; } @@ -2894,7 +2894,7 @@ static struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid) { struct nvme_ns *ns, *ret = NULL; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) { if (ns->head->ns_id == nsid) { if (!kref_get_unless_zero(&ns->kref)) @@ -2905,7 +2905,7 @@ static struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid) if (ns->head->ns_id > nsid) break; } - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); return ret; } @@ -3017,9 +3017,9 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) __nvme_revalidate_disk(disk, id); - mutex_lock(&ctrl->namespaces_mutex); + down_write(&ctrl->namespaces_rwsem); list_add_tail(&ns->list, &ctrl->namespaces); - mutex_unlock(&ctrl->namespaces_mutex); + up_write(&ctrl->namespaces_rwsem); nvme_get_ctrl(ctrl); @@ -3072,9 +3072,9 @@ static void nvme_ns_remove(struct nvme_ns *ns) list_del_rcu(&ns->siblings); mutex_unlock(&ns->ctrl->subsys->lock); - mutex_lock(&ns->ctrl->namespaces_mutex); + down_write(&ns->ctrl->namespaces_rwsem); list_del_init(&ns->list); - mutex_unlock(&ns->ctrl->namespaces_mutex); + up_write(&ns->ctrl->namespaces_rwsem); synchronize_srcu(&ns->head->srcu); nvme_mpath_check_last_path(ns); @@ -3100,14 +3100,14 @@ static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl, struct nvme_ns *ns, *next; LIST_HEAD(rm_list); - mutex_lock(&ctrl->namespaces_mutex); + down_write(&ctrl->namespaces_rwsem); list_for_each_entry_safe(ns, next, &ctrl->namespaces, list) { if (ns->head->ns_id > nsid) { list_del_init(&ns->list); list_add_tail(&ns->list, &rm_list); } } - mutex_unlock(&ctrl->namespaces_mutex); + up_write(&ctrl->namespaces_rwsem); list_for_each_entry_safe(ns, next, &rm_list, list) nvme_ns_remove(ns); @@ -3187,9 +3187,9 @@ static void nvme_scan_work(struct work_struct *work) } nvme_scan_ns_sequential(ctrl, nn); done: - mutex_lock(&ctrl->namespaces_mutex); + down_write(&ctrl->namespaces_rwsem); list_sort(NULL, &ctrl->namespaces, ns_cmp); - mutex_unlock(&ctrl->namespaces_mutex); + up_write(&ctrl->namespaces_rwsem); kfree(id); } @@ -3222,9 +3222,9 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl) if (ctrl->state == NVME_CTRL_DEAD) nvme_kill_queues(ctrl); - mutex_lock(&ctrl->namespaces_mutex); + down_write(&ctrl->namespaces_rwsem); list_splice_init(&ctrl->namespaces, &ns_list); - mutex_unlock(&ctrl->namespaces_mutex); + up_write(&ctrl->namespaces_rwsem); list_for_each_entry_safe(ns, next, &ns_list, list) nvme_ns_remove(ns); @@ -3413,7 +3413,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, ctrl->state = NVME_CTRL_NEW; spin_lock_init(&ctrl->lock); INIT_LIST_HEAD(&ctrl->namespaces); - mutex_init(&ctrl->namespaces_mutex); + init_rwsem(&ctrl->namespaces_rwsem); ctrl->dev = dev; ctrl->ops = ops; ctrl->quirks = quirks; @@ -3474,7 +3474,7 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl) { struct nvme_ns *ns; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); /* Forcibly unquiesce queues to avoid blocking dispatch */ if (ctrl->admin_q) @@ -3493,7 +3493,7 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl) /* Forcibly unquiesce queues to avoid blocking dispatch */ blk_mq_unquiesce_queue(ns->queue); } - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); } EXPORT_SYMBOL_GPL(nvme_kill_queues); @@ -3501,10 +3501,10 @@ void nvme_unfreeze(struct nvme_ctrl *ctrl) { struct nvme_ns *ns; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) blk_mq_unfreeze_queue(ns->queue); - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); } EXPORT_SYMBOL_GPL(nvme_unfreeze); @@ -3512,13 +3512,13 @@ void nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl, long timeout) { struct nvme_ns *ns; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) { timeout = blk_mq_freeze_queue_wait_timeout(ns->queue, timeout); if (timeout <= 0) break; } - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); } EXPORT_SYMBOL_GPL(nvme_wait_freeze_timeout); @@ -3526,10 +3526,10 @@ void nvme_wait_freeze(struct nvme_ctrl *ctrl) { struct nvme_ns *ns; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) blk_mq_freeze_queue_wait(ns->queue); - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); } EXPORT_SYMBOL_GPL(nvme_wait_freeze); @@ -3537,10 +3537,10 @@ void nvme_start_freeze(struct nvme_ctrl *ctrl) { struct nvme_ns *ns; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) blk_freeze_queue_start(ns->queue); - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); } EXPORT_SYMBOL_GPL(nvme_start_freeze); @@ -3548,10 +3548,10 @@ void nvme_stop_queues(struct nvme_ctrl *ctrl) { struct nvme_ns *ns; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) blk_mq_quiesce_queue(ns->queue); - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); } EXPORT_SYMBOL_GPL(nvme_stop_queues); @@ -3559,10 +3559,10 @@ void nvme_start_queues(struct nvme_ctrl *ctrl) { struct nvme_ns *ns; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) blk_mq_unquiesce_queue(ns->queue); - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); } EXPORT_SYMBOL_GPL(nvme_start_queues); diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 3b211d9..559b601 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -44,12 +44,12 @@ void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl) { struct nvme_ns *ns; - mutex_lock(&ctrl->namespaces_mutex); + down_read(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) { if (ns->head->disk) kblockd_schedule_work(&ns->head->requeue_work); } - mutex_unlock(&ctrl->namespaces_mutex); + up_read(&ctrl->namespaces_rwsem); } static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head) diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 8e4550f..4191650 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -140,7 +140,7 @@ struct nvme_ctrl { struct blk_mq_tag_set *tagset; struct blk_mq_tag_set *admin_tagset; struct list_head namespaces; - struct mutex namespaces_mutex; + struct rw_semaphore namespaces_rwsem; struct device ctrl_device; struct device *device; /* char device */ struct cdev cdev; -- 2.7.4