From patchwork Sun May 6 18:18:12 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [03/18] scsi: fix eh wakeup (scsi_schedule_eh vs scsi_restart_operations) From: Dan Williams X-Patchwork-Id: 157138 Message-Id: <> To: Cc: Tejun Heo ,, Tom Jackson Date: Sun, 06 May 2012 11:18:12 -0700 Rapid ata hotplug on a libsas controller results in cases where libsas is waiting indefinitely on eh to perform an ata probe. A race exists between scsi_schedule_eh() and scsi_restart_operations() in the case when scsi_restart_operations() issues i/o to other devices in the sas domain. When this happens the host state transitions from SHOST_RECOVERY (set by scsi_schedule_eh) back to SHOST_RUNNING and ->host_busy is non-zero so we put the eh thread to sleep even though ->host_eh_scheduled is active. Before putting the error handler to sleep we need to check if the host_state needs to return to SHOST_RECOVERY for another trip through eh. Cc: Tejun Heo Reported-by: Tom Jackson Tested-by: Tom Jackson Signed-off-by: Dan Williams --- drivers/scsi/scsi_error.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to More majordomo info at diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 386f0c5..cc8dc8c 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1687,6 +1687,20 @@ static void scsi_restart_operations(struct Scsi_Host *shost) * requests are started. */ scsi_run_host_queues(shost); + + /* + * if eh is active and host_eh_scheduled is pending we need to re-run + * recovery. we do this check after scsi_run_host_queues() to allow + * everything pent up since the last eh run a chance to make forward + * progress before we sync again. Either we'll immediately re-run + * recovery or scsi_device_unbusy() will wake us again when these + * pending commands complete. + */ + spin_lock_irqsave(shost->host_lock, flags); + if (shost->host_eh_scheduled) + if (scsi_host_set_state(shost, SHOST_RECOVERY)) + WARN_ON(scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)); + spin_unlock_irqrestore(shost->host_lock, flags); } /**