From: Damien Le Moal <damien.lemoal@wdc.com>
Date: Thu, 5 Sep 2019 18:51:29 +0900
Subject: [PATCH] block: Cleanup elevator_init_mq() use
References: bsc#1156419,jsc#SLE-8281
Git-commit: 61db437d1cc16c470cf6fccc04d34be9cf6e4e4b
Patch-mainline: v5.4-rc1
Instead of checking a queue tag_set BLK_MQ_F_NO_SCHED flag before
calling elevator_init_mq() to make sure that the queue supports IO
scheduling, use the elevator.c function elv_support_iosched() in
elevator_init_mq(). This does not introduce any functional change but
ensure that elevator_init_mq() does the right thing based on the queue
settings.
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.de>
---
block/blk-mq.c | 8 +++-----
block/elevator.c | 23 +++++++++++++----------
2 files changed, 16 insertions(+), 15 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 004411236034..c3bd5b48a5b1 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2910,11 +2910,9 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
blk_mq_add_queue_tag_set(set, q);
blk_mq_map_swqueue(q);
- if (!(set->flags & BLK_MQ_F_NO_SCHED)) {
- ret = elevator_init_mq(q);
- if (ret)
- goto err_tag_set;
- }
+ ret = elevator_init_mq(q);
+ if (ret)
+ goto err_tag_set;
return q;
diff --git a/block/elevator.c b/block/elevator.c
index 86100de88883..4721834815bb 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -619,16 +619,26 @@ int elevator_switch_mq(struct request_queue *q,
return ret;
}
+static inline bool elv_support_iosched(struct request_queue *q)
+{
+ if (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED))
+ return false;
+ return true;
+}
+
/*
- * For blk-mq devices, we default to using mq-deadline, if available, for single
- * queue devices. If deadline isn't available OR we have multiple queues,
- * default to "none".
+ * For blk-mq devices supporting IO scheduling, we default to using mq-deadline,
+ * if available, for single queue devices. If deadline isn't available OR we
+ * have multiple queues, default to "none".
*/
int elevator_init_mq(struct request_queue *q)
{
struct elevator_type *e;
int err = 0;
+ if (!elv_support_iosched(q))
+ return 0;
+
if (q->nr_hw_queues != 1)
return 0;
@@ -706,13 +716,6 @@ static int __elevator_change(struct request_queue *q, const char *name)
return elevator_switch(q, e);
}
-static inline bool elv_support_iosched(struct request_queue *q)
-{
- if (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED))
- return false;
- return true;
-}
-
ssize_t elv_iosched_store(struct request_queue *q, const char *name,
size_t count)
{
--
2.16.4