struct blk_mq_hw_ctx *hctx;
struct blk_mq_ctx *ctx;
struct request *rq;
- const bool is_flush = op & (REQ_PREFLUSH | REQ_FUA);
blk_queue_enter_live(q);
ctx = blk_mq_get_ctx(q);
hctx = blk_mq_map_queue(q, ctx->cpu);
- blk_mq_set_alloc_data(data, q, 0, ctx, hctx);
+ blk_mq_set_alloc_data(data, q, data->flags, ctx, hctx);
if (e) {
data->flags |= BLK_MQ_REQ_INTERNAL;
* Flush requests are special and go directly to the
* dispatch list.
*/
- if (!is_flush && e->type->ops.mq.get_request) {
+ if (!op_is_flush(op) && e->type->ops.mq.get_request) {
rq = e->type->ops.mq.get_request(q, op, data);
if (rq)
rq->rq_flags |= RQF_QUEUED;
rq = __blk_mq_alloc_request(data, op);
} else {
rq = __blk_mq_alloc_request(data, op);
- data->hctx->tags->rqs[rq->tag] = rq;
+ if (rq)
+ data->hctx->tags->rqs[rq->tag] = rq;
}
if (rq) {
- if (!is_flush) {
+ if (!op_is_flush(op)) {
rq->elv.icq = NULL;
if (e && e->type->icq_cache)
blk_mq_sched_assign_ioc(q, rq, bio);
* leave them there for as long as we can. Mark the hw queue as
* needing a restart in that case.
*/
- if (list_empty(&rq_list)) {
- if (e && e->type->ops.mq.dispatch_requests)
- e->type->ops.mq.dispatch_requests(hctx, &rq_list);
- else
- blk_mq_flush_busy_ctxs(hctx, &rq_list);
- } else
+ if (!list_empty(&rq_list)) {
blk_mq_sched_mark_restart(hctx);
-
- blk_mq_dispatch_rq_list(hctx, &rq_list);
+ blk_mq_dispatch_rq_list(hctx, &rq_list);
+ } else if (!e || !e->type->ops.mq.dispatch_request) {
+ blk_mq_flush_busy_ctxs(hctx, &rq_list);
+ blk_mq_dispatch_rq_list(hctx, &rq_list);
+ } else {
+ do {
+ struct request *rq;
+
+ rq = e->type->ops.mq.dispatch_request(hctx);
+ if (!rq)
+ break;
+ list_add(&rq->queuelist, &rq_list);
+ } while (blk_mq_dispatch_rq_list(hctx, &rq_list));
+ }
}
void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx,
}
EXPORT_SYMBOL_GPL(blk_mq_sched_move_to_dispatch);
-bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio)
+bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
+ struct request **merged_request)
{
struct request *rq;
- int ret;
- ret = elv_merge(q, &rq, bio);
- if (ret == ELEVATOR_BACK_MERGE) {
+ switch (elv_merge(q, &rq, bio)) {
+ case ELEVATOR_BACK_MERGE:
if (!blk_mq_sched_allow_merge(q, rq, bio))
return false;
- if (bio_attempt_back_merge(q, rq, bio)) {
- if (!attempt_back_merge(q, rq))
- elv_merged_request(q, rq, ret);
- return true;
- }
- } else if (ret == ELEVATOR_FRONT_MERGE) {
+ if (!bio_attempt_back_merge(q, rq, bio))
+ return false;
+ *merged_request = attempt_back_merge(q, rq);
+ if (!*merged_request)
+ elv_merged_request(q, rq, ELEVATOR_BACK_MERGE);
+ return true;
+ case ELEVATOR_FRONT_MERGE:
if (!blk_mq_sched_allow_merge(q, rq, bio))
return false;
- if (bio_attempt_front_merge(q, rq, bio)) {
- if (!attempt_front_merge(q, rq))
- elv_merged_request(q, rq, ret);
- return true;
- }
+ if (!bio_attempt_front_merge(q, rq, bio))
+ return false;
+ *merged_request = attempt_front_merge(q, rq);
+ if (!*merged_request)
+ elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE);
+ return true;
+ default:
+ return false;
}
-
- return false;
}
EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge);
}
EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted);
-bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, struct request *rq)
+static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx,
+ struct request *rq)
{
if (rq->tag == -1) {
rq->rq_flags |= RQF_SORTED;
spin_unlock(&hctx->lock);
return true;
}
-EXPORT_SYMBOL_GPL(blk_mq_sched_bypass_insert);
+
+static void blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) {
+ clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+ if (blk_mq_hctx_has_pending(hctx))
+ blk_mq_run_hw_queue(hctx, true);
+ }
+}
+
+void blk_mq_sched_restart_queues(struct blk_mq_hw_ctx *hctx)
+{
+ unsigned int i;
+
+ if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
+ blk_mq_sched_restart_hctx(hctx);
+ else {
+ struct request_queue *q = hctx->queue;
+
+ if (!test_bit(QUEUE_FLAG_RESTART, &q->queue_flags))
+ return;
+
+ clear_bit(QUEUE_FLAG_RESTART, &q->queue_flags);
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_sched_restart_hctx(hctx);
+ }
+}
+
+/*
+ * Add flush/fua to the queue. If we fail getting a driver tag, then
+ * punt to the requeue list. Requeue will re-invoke us from a context
+ * that's safe to block from.
+ */
+static void blk_mq_sched_insert_flush(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, bool can_block)
+{
+ if (blk_mq_get_driver_tag(rq, &hctx, can_block)) {
+ blk_insert_flush(rq);
+ blk_mq_run_hw_queue(hctx, true);
+ } else
+ blk_mq_add_to_requeue_list(rq, true, true);
+}
+
+void blk_mq_sched_insert_request(struct request *rq, bool at_head,
+ bool run_queue, bool async, bool can_block)
+{
+ struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+
+ if (rq->tag == -1 && op_is_flush(rq->cmd_flags)) {
+ blk_mq_sched_insert_flush(hctx, rq, can_block);
+ return;
+ }
+
+ if (e && blk_mq_sched_bypass_insert(hctx, rq))
+ goto run;
+
+ if (e && e->type->ops.mq.insert_requests) {
+ LIST_HEAD(list);
+
+ list_add(&rq->queuelist, &list);
+ e->type->ops.mq.insert_requests(hctx, &list, at_head);
+ } else {
+ spin_lock(&ctx->lock);
+ __blk_mq_insert_request(hctx, rq, at_head);
+ spin_unlock(&ctx->lock);
+ }
+
+run:
+ if (run_queue)
+ blk_mq_run_hw_queue(hctx, async);
+}
+
+void blk_mq_sched_insert_requests(struct request_queue *q,
+ struct blk_mq_ctx *ctx,
+ struct list_head *list, bool run_queue_async)
+{
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+ struct elevator_queue *e = hctx->queue->elevator;
+
+ if (e) {
+ struct request *rq, *next;
+
+ /*
+ * We bypass requests that already have a driver tag assigned,
+ * which should only be flushes. Flushes are only ever inserted
+ * as single requests, so we shouldn't ever hit the
+ * WARN_ON_ONCE() below (but let's handle it just in case).
+ */
+ list_for_each_entry_safe(rq, next, list, queuelist) {
+ if (WARN_ON_ONCE(rq->tag != -1)) {
+ list_del_init(&rq->queuelist);
+ blk_mq_sched_bypass_insert(hctx, rq);
+ }
+ }
+ }
+
+ if (e && e->type->ops.mq.insert_requests)
+ e->type->ops.mq.insert_requests(hctx, list, false);
+ else
+ blk_mq_insert_requests(hctx, ctx, list);
+
+ blk_mq_run_hw_queue(hctx, run_queue_async);
+}
static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set,
struct blk_mq_hw_ctx *hctx,
queue_for_each_hw_ctx(q, hctx, i)
blk_mq_sched_free_tags(set, hctx, i);
}
+
+int blk_mq_sched_init(struct request_queue *q)
+{
+ int ret;
+
+#if defined(CONFIG_DEFAULT_SQ_NONE)
+ if (q->nr_hw_queues == 1)
+ return 0;
+#endif
+#if defined(CONFIG_DEFAULT_MQ_NONE)
+ if (q->nr_hw_queues > 1)
+ return 0;
+#endif
+
+ mutex_lock(&q->sysfs_lock);
+ ret = elevator_init(q, NULL);
+ mutex_unlock(&q->sysfs_lock);
+
+ return ret;
+}
projects / linux-2.6-block.git / blobdiff