diff mbox series

block/rnbd-clt: Avoid flush_workqueue(system_long_wq) usage

Message ID 20220413123420.66470-1-jinpu.wang@ionos.com (mailing list archive)
State New, archived
Headers show
Series block/rnbd-clt: Avoid flush_workqueue(system_long_wq) usage | expand

Commit Message

Jinpu Wang April 13, 2022, 12:34 p.m. UTC 
Flushing system-wide workqueues is dangerous and will be forbidden.

Replace system_long_wq with local rnbd_clt_wq.

Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp

Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Santosh Kumar Pradhan <santosh.pradhan@ionos.com>
---
v2: return error as suggested by Tetsuo.

 drivers/block/rnbd/rnbd-clt.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

Comments

Tetsuo Handa April 18, 2022, 12:58 p.m. UTC | #1 
On 2022/04/13 21:34, Jack Wang wrote:
> Flushing system-wide workqueues is dangerous and will be forbidden.
> 
> Replace system_long_wq with local rnbd_clt_wq.
> 
> Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp
> 
> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
> Reviewed-by: Santosh Kumar Pradhan <santosh.pradhan@ionos.com>
> ---
> v2: return error as suggested by Tetsuo.
> 

Seems no more comments. Jens, please pick up.
Jens Axboe April 18, 2022, 3:25 p.m. UTC | #2 
On Wed, 13 Apr 2022 14:34:20 +0200, Jack Wang wrote:
> Flushing system-wide workqueues is dangerous and will be forbidden.
> 
> Replace system_long_wq with local rnbd_clt_wq.
> 
> Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp
> 
> 
> [...]

Applied, thanks!

[1/1] block/rnbd-clt: Avoid flush_workqueue(system_long_wq) usage
      commit: 5ea7c1339e3ed094dd4df48d598f9018a2587283

Best regards,
diff mbox series

Patch

diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
index b66e8840b94b..e21a35c0c62b 100644
--- a/drivers/block/rnbd/rnbd-clt.c
+++ b/drivers/block/rnbd/rnbd-clt.c
@@ -25,6 +25,7 @@  static int rnbd_client_major;
 static DEFINE_IDA(index_ida);
 static DEFINE_MUTEX(sess_lock);
 static LIST_HEAD(sess_list);
+static struct workqueue_struct *rnbd_clt_wq;
 
 /*
  * Maximum number of partitions an instance can have.
@@ -1761,12 +1762,12 @@  static void rnbd_destroy_sessions(void)
 			 * procedure takes minutes.
 			 */
 			INIT_WORK(&dev->unmap_on_rmmod_work, unmap_device_work);
-			queue_work(system_long_wq, &dev->unmap_on_rmmod_work);
+			queue_work(rnbd_clt_wq, &dev->unmap_on_rmmod_work);
 		}
 		rnbd_clt_put_sess(sess);
 	}
 	/* Wait for all scheduled unmap works */
-	flush_workqueue(system_long_wq);
+	flush_workqueue(rnbd_clt_wq);
 	WARN_ON(!list_empty(&sess_list));
 }
 
@@ -1791,6 +1792,14 @@  static int __init rnbd_client_init(void)
 		pr_err("Failed to load module, creating sysfs device files failed, err: %d\n",
 		       err);
 		unregister_blkdev(rnbd_client_major, "rnbd");
+		return err;
+	}
+	rnbd_clt_wq = alloc_workqueue("rnbd_clt_wq", 0, 0);
+	if (!rnbd_clt_wq) {
+		pr_err("Failed to load module, alloc_workqueue failed.\n");
+		rnbd_clt_destroy_sysfs_files();
+		unregister_blkdev(rnbd_client_major, "rnbd");
+		err = -ENOMEM;
 	}
 
 	return err;
@@ -1801,6 +1810,7 @@  static void __exit rnbd_client_exit(void)
 	rnbd_destroy_sessions();
 	unregister_blkdev(rnbd_client_major, "rnbd");
 	ida_destroy(&index_ida);
+	destroy_workqueue(rnbd_clt_wq);
 }
 
 module_init(rnbd_client_init);