/* The target wants to requeue the I/O */
dm_requeue_original_request(tio, false);
break;
+ case DM_ENDIO_DELAY_REQUEUE:
+ /* The target wants to requeue the I/O after a delay */
+ dm_requeue_original_request(tio, true);
+ break;
default:
DMWARN("unimplemented target endio return value: %d", r);
BUG();
clone->start_time = jiffies;
r = blk_insert_cloned_request(clone->q, clone);
- if (r != BLK_STS_OK && r != BLK_STS_RESOURCE)
+ if (r != BLK_STS_OK && r != BLK_STS_RESOURCE && r != BLK_STS_DEV_RESOURCE)
/* must complete clone in terms of original request */
dm_complete_request(rq, r);
return r;
trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
blk_rq_pos(rq));
ret = dm_dispatch_clone_request(clone, rq);
- if (ret == BLK_STS_RESOURCE) {
+ if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) {
blk_rq_unprep_clone(clone);
tio->ti->type->release_clone_rq(clone);
tio->clone = NULL;
/* disable dm_old_request_fn's merge heuristic by default */
md->seq_rq_merge_deadline_usecs = 0;
- dm_init_normal_md_queue(md);
blk_queue_softirq_done(md->queue, dm_softirq_done);
/* Initialize the request-based DM worker thread */
/* Undo dm_start_request() before requeuing */
rq_end_stats(md, rq);
rq_completed(md, rq_data_dir(rq), false);
- blk_mq_delay_run_hw_queue(hctx, 100/*ms*/);
return BLK_STS_RESOURCE;
}
err = PTR_ERR(q);
goto out_tag_set;
}
- dm_init_md_queue(md);
return 0;
* for a requeue after completion, which should only occur in this
* file.
*/
-static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
+static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
{
struct scsi_device *device = cmd->device;
struct request_queue *q = device->request_queue;
*/
void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
{
- __scsi_queue_insert(cmd, reason, 1);
+ __scsi_queue_insert(cmd, reason, true);
}
cmd->cmd_len = scsi_command_size(cmd->cmnd);
}
-void scsi_device_unbusy(struct scsi_device *sdev)
+/*
+ * Decrement the host_busy counter and wake up the error handler if necessary.
+ * Avoid as follows that the error handler is not woken up if shost->host_busy
+ * == shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination
+ * with an RCU read lock in this function to ensure that this function in its
+ * entirety either finishes before scsi_eh_scmd_add() increases the
+ * host_failed counter or that it notices the shost state change made by
+ * scsi_eh_scmd_add().
+ */
+static void scsi_dec_host_busy(struct Scsi_Host *shost)
{
- struct Scsi_Host *shost = sdev->host;
- struct scsi_target *starget = scsi_target(sdev);
unsigned long flags;
+ rcu_read_lock();
atomic_dec(&shost->host_busy);
- if (starget->can_queue > 0)
- atomic_dec(&starget->target_busy);
-
- if (unlikely(scsi_host_in_recovery(shost) &&
- (shost->host_failed || shost->host_eh_scheduled))) {
+ if (unlikely(scsi_host_in_recovery(shost))) {
spin_lock_irqsave(shost->host_lock, flags);
- scsi_eh_wakeup(shost);
+ if (shost->host_failed || shost->host_eh_scheduled)
+ scsi_eh_wakeup(shost);
spin_unlock_irqrestore(shost->host_lock, flags);
}
+ rcu_read_unlock();
+}
+
+void scsi_device_unbusy(struct scsi_device *sdev)
+{
+ struct Scsi_Host *shost = sdev->host;
+ struct scsi_target *starget = scsi_target(sdev);
+
+ scsi_dec_host_busy(shost);
+
+ if (starget->can_queue > 0)
+ atomic_dec(&starget->target_busy);
atomic_dec(&sdev->device_busy);
}
break;
case ACTION_RETRY:
/* Retry the same command immediately */
- __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
+ __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false);
break;
case ACTION_DELAYED_RETRY:
/* Retry the same command after a delay */
- __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
+ __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false);
break;
}
}
* Called from inside blk_get_request() for pass-through requests and from
* inside scsi_init_command() for filesystem requests.
*/
-void scsi_initialize_rq(struct request *rq)
+static void scsi_initialize_rq(struct request *rq)
{
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
cmd->jiffies_at_alloc = jiffies;
cmd->retries = 0;
}
-EXPORT_SYMBOL(scsi_initialize_rq);
/* Add a command to the list used by the aacraid and dpt_i2o drivers */
void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
list_add_tail(&sdev->starved_entry, &shost->starved_list);
spin_unlock_irq(shost->host_lock);
out_dec:
- atomic_dec(&shost->host_busy);
+ scsi_dec_host_busy(shost);
return 0;
}
return BLK_STS_OK;
out_dec_host_busy:
- atomic_dec(&shost->host_busy);
+ scsi_dec_host_busy(shost);
out_dec_target_busy:
if (scsi_target(sdev)->can_queue > 0)
atomic_dec(&scsi_target(sdev)->target_busy);
case BLK_STS_OK:
break;
case BLK_STS_RESOURCE:
- if (atomic_read(&sdev->device_busy) == 0 &&
- !scsi_device_blocked(sdev))
- blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
+ if (atomic_read(&sdev->device_busy) ||
+ scsi_device_blocked(sdev))
+ ret = BLK_STS_DEV_RESOURCE;
break;
default:
/*