Re: kernel 5.0 blk_clear_pm_only triggers a warning during resume

[Bart Van Assche <bvanassche@acm.org>]

On Tue, 2019-03-12 at 05:35 +0000, Jisheng Zhang wrote:
> I got below warning during resume:
> 
> [  673.658888] sd 0:0:0:0: [sda] Starting disk
> [  673.658899] WARNING: CPU: 3 PID: 1039 at blk_clear_pm_only+0x2a/0x30
> [  673.658902] CPU: 3 PID: 1039 Comm: kworker/u8:49 Not tainted 5.0.0+ #1
> [  673.658902] sd 2:0:0:0: [sdb] Starting disk
> [  673.658903] Hardware name: LENOVO 4180F42/4180F42, BIOS 83ET75WW (1.45 ) 05/10/2013
> [  673.658906] Workqueue: events_unbound async_run_entry_fn
> [  673.658909] RIP: 0010:blk_clear_pm_only+0x2a/0x30
> [  673.658911] Code: b8 ff ff ff ff f0 0f c1 87 80 00 00 00 83 e8 01 78 18 74 01 c3 48 81 c7 58 05 00 00 31 c9 31 d2 be 03 00 00 00 e9 36 97 e2 ff <0f> 0b c3 0f 1f 00 48 81 c7 90 00 00 00 e9 04 01
> 3a 00 0f 1f 40 00
> [  673.658911] RSP: 0000:ffff8881115a7e48 EFLAGS: 00010297
> [  673.658913] RAX: 00000000ffffffff RBX: ffff888118d42800 RCX: ffff8881194c9a00
> [  673.658914] RDX: ffff888118ab1a00 RSI: 0000000000000000 RDI: ffff888117e70000
> [  673.658915] RBP: ffff888118d42f90 R08: 0000000000000004 R09: 000000000001f900
> [  673.658915] R10: 0000000045698a8e R11: 0000000000000010 R12: ffff888119421000
> [  673.658916] R13: 0000000000000000 R14: ffff88800030ea80 R15: 0ffff88811942100
> [  673.658918] FS:  0000000000000000(0000) GS:ffff88811a180000(0000) knlGS:0000000000000000
> [  673.658918] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  673.658919] CR2: 0000000000000000 CR3: 000000000200c001 CR4: 00000000000606e0
> [  673.658920] Call Trace:
> [  673.658924]  ? scsi_device_resume+0x28/0x50
> [  673.658926]  ? scsi_dev_type_resume+0x2b/0x80
> [  673.658927]  ? async_run_entry_fn+0x2c/0xd0
> [  673.658930]  ? process_one_work+0x1f0/0x3f0
> [  673.658932]  ? worker_thread+0x28/0x3c0
> [  673.658933]  ? process_one_work+0x3f0/0x3f0
> [  673.658935]  ? kthread+0x10c/0x130
> [  673.658936]  ? __kthread_create_on_node+0x150/0x150
> [  673.658938]  ? ret_from_fork+0x1f/0x30
> [  673.658940] ---[ end trace ce18772de33e283e ]---

Hi Jisheng,

Is this something that occurred once or is this something that you can reproduce
easily? In the latter case, can you verify whether the patch below is sufficient
to make this warning disappear?

Thanks,

Bart.

---
 drivers/scsi/scsi_lib.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index f3f24dfd8fd5..33e1a72d47fa 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2540,8 +2540,10 @@ void scsi_device_resume(struct scsi_device *sdev)
 	 * device deleted during suspend)
 	 */
 	mutex_lock(&sdev->state_mutex);
-	sdev->quiesced_by = NULL;
-	blk_clear_pm_only(sdev->request_queue);
+	if (sdev->quiesced_by) {
+		sdev->quiesced_by = NULL;
+		blk_clear_pm_only(sdev->request_queue);
+	}
 	if (sdev->sdev_state == SDEV_QUIESCE)
 		scsi_device_set_state(sdev, SDEV_RUNNING);
 	mutex_unlock(&sdev->state_mutex);