+ return 0;
+}
+
+static int dm_mq_init_request(void *data, struct request *rq,
+ unsigned int hctx_idx, unsigned int request_idx,
+ unsigned int numa_node)
+{
+ struct mapped_device *md = data;
+ struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq);
+
+ /*
+ * Must initialize md member of tio, otherwise it won't
+ * be available in dm_mq_queue_rq.
+ */
+ tio->md = md;
+
+ return 0;
+}
+
+static int dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *bd)
+{
+ struct request *rq = bd->rq;
+ struct dm_rq_target_io *tio = blk_mq_rq_to_pdu(rq);
+ struct mapped_device *md = tio->md;
+ int srcu_idx;
+ struct dm_table *map = dm_get_live_table(md, &srcu_idx);
+ struct dm_target *ti;
+ sector_t pos;
+
+ /* always use block 0 to find the target for flushes for now */
+ pos = 0;
+ if (!(rq->cmd_flags & REQ_FLUSH))
+ pos = blk_rq_pos(rq);
+
+ ti = dm_table_find_target(map, pos);
+ if (!dm_target_is_valid(ti)) {
+ dm_put_live_table(md, srcu_idx);
+ DMERR_LIMIT("request attempted access beyond the end of device");
+ /*
+ * Must perform setup, that rq_completed() requires,
+ * before returning BLK_MQ_RQ_QUEUE_ERROR
+ */
+ dm_start_request(md, rq);
+ return BLK_MQ_RQ_QUEUE_ERROR;
+ }
+ dm_put_live_table(md, srcu_idx);
+
+ if (ti->type->busy && ti->type->busy(ti))
+ return BLK_MQ_RQ_QUEUE_BUSY;
+
+ dm_start_request(md, rq);
+
+ /* Init tio using md established in .init_request */
+ init_tio(tio, rq, md);
+
+ /* Establish tio->ti before queuing work (map_tio_request) */
+ tio->ti = ti;
+ queue_kthread_work(&md->kworker, &tio->work);
+
+ return BLK_MQ_RQ_QUEUE_OK;
+}
+
+static struct blk_mq_ops dm_mq_ops = {
+ .queue_rq = dm_mq_queue_rq,
+ .map_queue = blk_mq_map_queue,
+ .complete = dm_softirq_done,
+ .init_request = dm_mq_init_request,
+};
+
+static int dm_init_request_based_blk_mq_queue(struct mapped_device *md)
+{
+ struct request_queue *q;
+ int err;
+
+ memset(&md->tag_set, 0, sizeof(md->tag_set));
+ md->tag_set.ops = &dm_mq_ops;
+ md->tag_set.queue_depth = BLKDEV_MAX_RQ;
+ md->tag_set.numa_node = NUMA_NO_NODE;
+ md->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
+ md->tag_set.nr_hw_queues = 1;
+ md->tag_set.cmd_size = sizeof(struct dm_rq_target_io);
+ md->tag_set.driver_data = md;
+
+ err = blk_mq_alloc_tag_set(&md->tag_set);
+ if (err)
+ return err;
+
+ q = blk_mq_init_allocated_queue(&md->tag_set, md->queue);
+ if (IS_ERR(q)) {
+ err = PTR_ERR(q);
+ goto out_tag_set;
+ }
+ md->queue = q;
+ dm_init_md_queue(md);
+
+ /* backfill 'mq' sysfs registration normally done in blk_register_queue */
+ blk_mq_register_disk(md->disk);
+
+ init_rq_based_worker_thread(md);
+
+ return 0;
+
+out_tag_set:
+ blk_mq_free_tag_set(&md->tag_set);
+ return err;
projects / linux.git / commitdiff