blk-mq-sched: refactor scheduler initialization
Preparation cleanup for the next couple of fixes, push
blk_mq_sched_setup() and e->ops.mq.init_sched() into a helper.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index fc00f00..6bd1758e 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -432,51 +432,23 @@ static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set,
}
}
-int blk_mq_sched_setup(struct request_queue *q)
+static int blk_mq_sched_alloc_tags(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx)
{
struct blk_mq_tag_set *set = q->tag_set;
- struct blk_mq_hw_ctx *hctx;
- int ret, i;
+ int ret;
- /*
- * Default to 256, since we don't split into sync/async like the
- * old code did. Additionally, this is a per-hw queue depth.
- */
- q->nr_requests = 2 * BLKDEV_MAX_RQ;
+ hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests,
+ set->reserved_tags);
+ if (!hctx->sched_tags)
+ return -ENOMEM;
- /*
- * We're switching to using an IO scheduler, so setup the hctx
- * scheduler tags and switch the request map from the regular
- * tags to scheduler tags. First allocate what we need, so we
- * can safely fail and fallback, if needed.
- */
- ret = 0;
- queue_for_each_hw_ctx(q, hctx, i) {
- hctx->sched_tags = blk_mq_alloc_rq_map(set, i,
- q->nr_requests, set->reserved_tags);
- if (!hctx->sched_tags) {
- ret = -ENOMEM;
- break;
- }
- ret = blk_mq_alloc_rqs(set, hctx->sched_tags, i, q->nr_requests);
- if (ret)
- break;
- }
+ ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests);
+ if (ret)
+ blk_mq_sched_free_tags(set, hctx, hctx_idx);
- /*
- * If we failed, free what we did allocate
- */
- if (ret) {
- queue_for_each_hw_ctx(q, hctx, i) {
- if (!hctx->sched_tags)
- continue;
- blk_mq_sched_free_tags(set, hctx, i);
- }
-
- return ret;
- }
-
- return 0;
+ return ret;
}
void blk_mq_sched_teardown(struct request_queue *q)
@@ -489,6 +461,40 @@ void blk_mq_sched_teardown(struct request_queue *q)
blk_mq_sched_free_tags(set, hctx, i);
}
+int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+ int ret;
+
+ if (!e) {
+ q->elevator = NULL;
+ return 0;
+ }
+
+ /*
+ * Default to 256, since we don't split into sync/async like the
+ * old code did. Additionally, this is a per-hw queue depth.
+ */
+ q->nr_requests = 2 * BLKDEV_MAX_RQ;
+
+ queue_for_each_hw_ctx(q, hctx, i) {
+ ret = blk_mq_sched_alloc_tags(q, hctx, i);
+ if (ret)
+ goto err;
+ }
+
+ ret = e->ops.mq.init_sched(q, e);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ blk_mq_sched_teardown(q);
+ return ret;
+}
+
int blk_mq_sched_init(struct request_queue *q)
{
int ret;