struct scsi_request *rq;
int ret = DRIVER_ERROR << 24;
- req = blk_get_request(sdev->request_queue,
+ req = blk_get_request_flags(sdev->request_queue,
data_direction == DMA_TO_DEVICE ?
- REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, __GFP_RECLAIM);
+ REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, BLK_MQ_REQ_PREEMPT);
if (IS_ERR(req))
return ret;
rq = scsi_req(req);
rq->retries = retries;
req->timeout = timeout;
req->cmd_flags |= flags;
- req->rq_flags |= rq_flags | RQF_QUIET | RQF_PREEMPT;
+ req->rq_flags |= rq_flags | RQF_QUIET;
/*
* head injection *required* here otherwise quiesce won't work
/*
* If the devices is blocked we defer normal commands.
*/
- if (!(req->rq_flags & RQF_PREEMPT))
+ if (req && !(req->rq_flags & RQF_PREEMPT))
ret = BLKPREP_DEFER;
break;
default:
* special commands. In particular any user initiated
* command is not allowed.
*/
- if (!(req->rq_flags & RQF_PREEMPT))
+ if (req && !(req->rq_flags & RQF_PREEMPT))
ret = BLKPREP_KILL;
break;
}
ret = scsi_setup_cmnd(sdev, req);
out:
- if (ret != BLKPREP_OK)
- cmd->flags &= ~SCMD_INITIALIZED;
return scsi_prep_return(q, req, ret);
}
struct scsi_device *sdev = req->q->queuedata;
struct Scsi_Host *shost = sdev->host;
struct scatterlist *sg;
- int ret;
scsi_init_command(sdev, cmd);
blk_mq_start_request(req);
- ret = scsi_setup_cmnd(sdev, req);
- if (ret != BLK_STS_OK)
- cmd->flags &= ~SCMD_INITIALIZED;
- return ret;
+ return scsi_setup_cmnd(sdev, req);
}
static void scsi_mq_done(struct scsi_cmnd *cmd)
blk_mq_complete_request(cmd->request);
}
+static void scsi_mq_put_budget(struct blk_mq_hw_ctx *hctx)
+{
+ struct request_queue *q = hctx->queue;
+ struct scsi_device *sdev = q->queuedata;
+
+ atomic_dec(&sdev->device_busy);
+ put_device(&sdev->sdev_gendev);
+}
+
+static bool scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx)
+{
+ struct request_queue *q = hctx->queue;
+ struct scsi_device *sdev = q->queuedata;
+
+ if (!get_device(&sdev->sdev_gendev))
+ goto out;
+ if (!scsi_dev_queue_ready(q, sdev))
+ goto out_put_device;
+
+ return true;
+
+out_put_device:
+ put_device(&sdev->sdev_gendev);
+out:
+ return false;
+}
+
static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *bd)
{
ret = prep_to_mq(scsi_prep_state_check(sdev, req));
if (ret != BLK_STS_OK)
- goto out;
+ goto out_put_budget;
ret = BLK_STS_RESOURCE;
- if (!get_device(&sdev->sdev_gendev))
- goto out;
-
- if (!scsi_dev_queue_ready(q, sdev))
- goto out_put_device;
if (!scsi_target_queue_ready(shost, sdev))
- goto out_dec_device_busy;
+ goto out_put_budget;
if (!scsi_host_queue_ready(q, shost, sdev))
goto out_dec_target_busy;
return BLK_STS_OK;
out_dec_host_busy:
- atomic_dec(&shost->host_busy);
+ atomic_dec(&shost->host_busy);
out_dec_target_busy:
if (scsi_target(sdev)->can_queue > 0)
atomic_dec(&scsi_target(sdev)->target_busy);
-out_dec_device_busy:
- atomic_dec(&sdev->device_busy);
-out_put_device:
- put_device(&sdev->sdev_gendev);
-out:
+out_put_budget:
+ scsi_mq_put_budget(hctx);
switch (ret) {
case BLK_STS_OK:
break;
}
static const struct blk_mq_ops scsi_mq_ops = {
+ .get_budget = scsi_mq_get_budget,
+ .put_budget = scsi_mq_put_budget,
.queue_rq = scsi_queue_rq,
.complete = scsi_softirq_done,
.timeout = scsi_timeout,
}
sdev->sdev_state = state;
- sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
return 0;
illegal:
int
scsi_device_quiesce(struct scsi_device *sdev)
{
+ struct request_queue *q = sdev->request_queue;
int err;
+ /*
+ * It is allowed to call scsi_device_quiesce() multiple times from
+ * the same context but concurrent scsi_device_quiesce() calls are
+ * not allowed.
+ */
+ WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current);
+
+ blk_set_preempt_only(q);
+
+ blk_mq_freeze_queue(q);
+ /*
+ * Ensure that the effect of blk_set_preempt_only() will be visible
+ * for percpu_ref_tryget() callers that occur after the queue
+ * unfreeze even if the queue was already frozen before this function
+ * was called. See also https://lwn.net/Articles/573497/.
+ */
+ synchronize_rcu();
+ blk_mq_unfreeze_queue(q);
+
mutex_lock(&sdev->state_mutex);
err = scsi_device_set_state(sdev, SDEV_QUIESCE);
+ if (err == 0)
+ sdev->quiesced_by = current;
+ else
+ blk_clear_preempt_only(q);
mutex_unlock(&sdev->state_mutex);
- if (err)
- return err;
-
- scsi_run_queue(sdev->request_queue);
- while (atomic_read(&sdev->device_busy)) {
- msleep_interruptible(200);
- scsi_run_queue(sdev->request_queue);
- }
- return 0;
+ return err;
}
EXPORT_SYMBOL(scsi_device_quiesce);
* device deleted during suspend)
*/
mutex_lock(&sdev->state_mutex);
- if (sdev->sdev_state == SDEV_QUIESCE &&
- scsi_device_set_state(sdev, SDEV_RUNNING) == 0)
- scsi_run_queue(sdev->request_queue);
+ WARN_ON_ONCE(!sdev->quiesced_by);
+ sdev->quiesced_by = NULL;
+ blk_clear_preempt_only(sdev->request_queue);
+ if (sdev->sdev_state == SDEV_QUIESCE)
+ scsi_device_set_state(sdev, SDEV_RUNNING);
mutex_unlock(&sdev->state_mutex);
}
EXPORT_SYMBOL(scsi_device_resume);
case SDEV_BLOCK:
case SDEV_TRANSPORT_OFFLINE:
sdev->sdev_state = new_state;
- sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
break;
case SDEV_CREATED_BLOCK:
if (new_state == SDEV_TRANSPORT_OFFLINE ||
sdev->sdev_state = new_state;
else
sdev->sdev_state = SDEV_CREATED;
- sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
break;
case SDEV_CANCEL:
case SDEV_OFFLINE:
projects / linux-2.6-microblaze.git / blobdiff