diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2012-06-21 23:25:32 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-08-02 14:37:56 +0100 |
| commit | c6e92669dd2703bd2243c2b16cd5a5283135151b (patch) | |
| tree | b9060c2cae89a003f909a61014253dcd65c99f16 | |
| parent | f60c4d00f7e25849c1e743cf66fde70bdac63dae (diff) | |
fix eh wakeup (scsi_schedule_eh vs scsi_restart_operations)
commit 57fc2e335fd3c2f898ee73570dc81426c28dc7b4 upstream.
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. Since i/o that is released by scsi_restart_operations has been
blocked for at least one eh cycle, this implementation allows those
i/o's to run before another eh cycle starts to discourage hung task
timeouts.
Reported-by: Tom Jackson <thomas.p.jackson@intel.com>
Tested-by: Tom Jackson <thomas.p.jackson@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/scsi/scsi_error.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index dc6131e6a1ba..456b1317235a 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1673,6 +1673,20 @@ 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); } /** |