From 8832cf922151e9dfa2821736beb0ae2dd3968b6e Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Mon, 21 Mar 2022 13:57:27 +0200 Subject: nvmet: use a private workqueue instead of the system workqueue Any attempt to flush kernel-global WQs has possibility of deadlock so we should simply stop using them, instead introduce nvmet_wq which is the generic nvmet workqueue for work elements that don't explicitly require a dedicated workqueue (by the mere fact that they are using the system_wq). Changes were done using the following replaces: - s/schedule_work(/queue_work(nvmet_wq, /g - s/schedule_delayed_work(/queue_delayed_work(nvmet_wq, /g - s/flush_scheduled_work()/flush_workqueue(nvmet_wq)/g Reported-by: Tetsuo Handa Signed-off-by: Sagi Grimberg Reviewed-by: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig --- drivers/nvme/target/core.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) (limited to 'drivers/nvme/target/core.c') diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index 92af37d33ec3..cd833b1dd47c 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -20,6 +20,9 @@ struct workqueue_struct *zbd_wq; static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX]; static DEFINE_IDA(cntlid_ida); +struct workqueue_struct *nvmet_wq; +EXPORT_SYMBOL_GPL(nvmet_wq); + /* * This read/write semaphore is used to synchronize access to configuration * information on a target system that will result in discovery log page @@ -205,7 +208,7 @@ void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type, list_add_tail(&aen->entry, &ctrl->async_events); mutex_unlock(&ctrl->lock); - schedule_work(&ctrl->async_event_work); + queue_work(nvmet_wq, &ctrl->async_event_work); } static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid) @@ -385,7 +388,7 @@ static void nvmet_keep_alive_timer(struct work_struct *work) if (reset_tbkas) { pr_debug("ctrl %d reschedule traffic based keep-alive timer\n", ctrl->cntlid); - schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); + queue_delayed_work(nvmet_wq, &ctrl->ka_work, ctrl->kato * HZ); return; } @@ -403,7 +406,7 @@ void nvmet_start_keep_alive_timer(struct nvmet_ctrl *ctrl) pr_debug("ctrl %d start keep-alive timer for %d secs\n", ctrl->cntlid, ctrl->kato); - schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ); + queue_delayed_work(nvmet_wq, &ctrl->ka_work, ctrl->kato * HZ); } void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl) @@ -1478,7 +1481,7 @@ void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl) mutex_lock(&ctrl->lock); if (!(ctrl->csts & NVME_CSTS_CFS)) { ctrl->csts |= NVME_CSTS_CFS; - schedule_work(&ctrl->fatal_err_work); + queue_work(nvmet_wq, &ctrl->fatal_err_work); } mutex_unlock(&ctrl->lock); } @@ -1620,9 +1623,15 @@ static int __init nvmet_init(void) goto out_free_zbd_work_queue; } + nvmet_wq = alloc_workqueue("nvmet-wq", WQ_MEM_RECLAIM, 0); + if (!nvmet_wq) { + error = -ENOMEM; + goto out_free_buffered_work_queue; + } + error = nvmet_init_discovery(); if (error) - goto out_free_work_queue; + goto out_free_nvmet_work_queue; error = nvmet_init_configfs(); if (error) @@ -1631,7 +1640,9 @@ static int __init nvmet_init(void) out_exit_discovery: nvmet_exit_discovery(); -out_free_work_queue: +out_free_nvmet_work_queue: + destroy_workqueue(nvmet_wq); +out_free_buffered_work_queue: destroy_workqueue(buffered_io_wq); out_free_zbd_work_queue: destroy_workqueue(zbd_wq); @@ -1643,6 +1654,7 @@ static void __exit nvmet_exit(void) nvmet_exit_configfs(); nvmet_exit_discovery(); ida_destroy(&cntlid_ida); + destroy_workqueue(nvmet_wq); destroy_workqueue(buffered_io_wq); destroy_workqueue(zbd_wq); -- cgit v1.2.3