diff mbox

[0/9] block/scsi: safe SCSI quiescing

Message ID 20170901034532.GD16525@ming.t460p (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Ming Lei Sept. 1, 2017, 3:45 a.m. UTC 
On Thu, Aug 31, 2017 at 08:31:54PM +0200, Oleksandr Natalenko wrote:
> Tested against v4.13-rc7. With this patchset it looks like I/O doesn't hang, 
> but once (just once, not each time) I've got the following stacktrace on 
> resume:

That looks not bad, and thanks for your test!

Could you try the following patch against this patchset to see
if there is still the warning?

Comments

Oleksandr Natalenko Sept. 1, 2017, 6:24 a.m. UTC | #1 
Hi.

01.09.2017 05:45, Ming Lei wrote:
> Could you try the following patch against this patchset to see
> if there is still the warning?

With this patch I wasn't able to trigger per-CPU-related warning.

Also, for 8th patch you've written:

> I have sent one delta patch in list, which will only call 
> blk_queue_enter_live() iff SCSI device is in QUIESCE.

This refers to the patch I've just tested, right?
Ming Lei Sept. 1, 2017, 6:30 a.m. UTC | #2 
On Fri, Sep 01, 2017 at 08:24:46AM +0200, oleksandr@natalenko.name wrote:
> Hi.
> 
> 01.09.2017 05:45, Ming Lei wrote:
> > Could you try the following patch against this patchset to see
> > if there is still the warning?
> 
> With this patch I wasn't able to trigger per-CPU-related warning.

That is great!

> 
> Also, for 8th patch you've written:
> 
> > I have sent one delta patch in list, which will only call
> > blk_queue_enter_live() iff SCSI device is in QUIESCE.
> 
> This refers to the patch I've just tested, right?

Yeah, you are right, thanks again for your test!

I will prepare V2 and send it out soon.
diff mbox

Patch

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b9ad8aeb456f..bbd85ddad18c 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -243,11 +243,12 @@  int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 	struct request *req;
 	struct scsi_request *rq;
 	int ret = DRIVER_ERROR << 24;
+	unsigned flag = sdev->sdev_state == SDEV_QUIESCE ? BLK_REQ_PREEMPT : 0;
 
 	req = __blk_get_request(sdev->request_queue,
 			data_direction == DMA_TO_DEVICE ?
 			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, __GFP_RECLAIM,
-			BLK_REQ_PREEMPT);
+			flag);
 	if (IS_ERR(req))
 		return ret;
 	rq = scsi_req(req);
@@ -2931,11 +2932,6 @@  EXPORT_SYMBOL(scsi_device_quiesce);
  */
 void scsi_device_resume(struct scsi_device *sdev)
 {
-	/* wait for completion of IO issued during SCSI quiese */
-	blk_freeze_queue_wait(sdev->request_queue);
-
-	blk_unfreeze_queue(sdev->request_queue);
-
 	/* check if the device state was mutated prior to resume, and if
 	 * so assume the state is being managed elsewhere (for example
 	 * device deleted during suspend)
@@ -2945,6 +2941,11 @@  void scsi_device_resume(struct scsi_device *sdev)
 	    scsi_device_set_state(sdev, SDEV_RUNNING) == 0)
 		scsi_run_queue(sdev->request_queue);
 	mutex_unlock(&sdev->state_mutex);
+
+	/* wait for completion of IO issued during SCSI quiese */
+	blk_freeze_queue_wait(sdev->request_queue);
+
+	blk_unfreeze_queue(sdev->request_queue);
 }
 EXPORT_SYMBOL(scsi_device_resume);