Hello Bart.
What is this one about?
Fix for the regression I (and others?) reported?ยน
[1] [Bug 199077] [Possible REGRESSION, 4.16-rc4] Error updating SMART data during runtime and boot failures with blk_mq_terminate_expired in backtrace
https://bugzilla.kernel.org/show_bug.cgi?id=199077
Thanks, Martin
Bart Van Assche - 16.03.18, 18:35:
Since blk_queue_enter() uses rcu_read_lock_sched() scsi_device_quiesce() must use synchronize_sched().
Reported-by: Tejun Heo tj@kernel.org Fixes: 3a0a529971ec ("block, scsi: Make SCSI quiesce and resume work reliably") Signed-off-by: Bart Van Assche bart.vanassche@wdc.com Cc: Hannes Reinecke hare@suse.com Cc: Ming Lei ming.lei@redhat.com Cc: Christoph Hellwig hch@lst.de Cc: Johannes Thumshirn jthumshirn@suse.de Cc: Tejun Heo tj@kernel.org Cc: Oleksandr Natalenko oleksandr@natalenko.name Cc: Martin Steigerwald martin@lichtvoll.de Cc: stable@vger.kernel.org # v4.15
drivers/scsi/scsi_lib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 1d83f29aee74..0b99ee2fbbb5 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -3014,7 +3014,7 @@ scsi_device_quiesce(struct scsi_device *sdev) * unfreeze even if the queue was already frozen before this function * was called. See also https://lwn.net/Articles/573497/. */
- synchronize_rcu();
synchronize_sched(); blk_mq_unfreeze_queue(q);
mutex_lock(&sdev->state_mutex);