[PATCH v3 1/5] block: Optimize bio io priority setting

[Hongyu Jin <hongyu.jin.cn@xxxxxxxxx>]

From: Hongyu Jin <hongyu.jin@xxxxxxxxxx>

Current call bio_set_ioprio() for each cloned bio and splited bio,
and the io priority can't be passed to module that implement
struct gendisk::fops::submit_bio, such as device-mapper.

Move bio_set_ioprio() into submit_bio(), only call bio_set_ioprio()
once set the priority of origin bio, cloned and splited bio
auto inherit the priority of origin bio in clone process.

Co-developed-by: Yibin Ding <yibin.ding@xxxxxxxxxx>
Signed-off-by: Yibin Ding <yibin.ding@xxxxxxxxxx>
Signed-off-by: Hongyu Jin <hongyu.jin@xxxxxxxxxx>
---
 block/blk-core.c | 10 ++++++++++
 block/blk-mq.c   | 11 -----------
 2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index fdf25b8d6e78..68158c327aea 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -49,6 +49,7 @@
 #include "blk-pm.h"
 #include "blk-cgroup.h"
 #include "blk-throttle.h"
+#include "blk-ioprio.h"
 
 struct dentry *blk_debugfs_root;
 
@@ -809,6 +810,14 @@ void submit_bio_noacct(struct bio *bio)
 }
 EXPORT_SYMBOL(submit_bio_noacct);
 
+static void bio_set_ioprio(struct bio *bio)
+{
+	/* Nobody set ioprio so far? Initialize it based on task's nice value */
+	if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) == IOPRIO_CLASS_NONE)
+		bio->bi_ioprio = get_current_ioprio();
+	blkcg_set_ioprio(bio);
+}
+
 /**
  * submit_bio - submit a bio to the block device layer for I/O
  * @bio: The &struct bio which describes the I/O
@@ -831,6 +840,7 @@ void submit_bio(struct bio *bio)
 		count_vm_events(PGPGOUT, bio_sectors(bio));
 	}
 
+	bio_set_ioprio(bio);
 	submit_bio_noacct(bio);
 }
 EXPORT_SYMBOL(submit_bio);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index e2d11183f62e..a6e2609df9c9 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -40,7 +40,6 @@
 #include "blk-stat.h"
 #include "blk-mq-sched.h"
 #include "blk-rq-qos.h"
-#include "blk-ioprio.h"
 
 static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
 static DEFINE_PER_CPU(call_single_data_t, blk_cpu_csd);
@@ -2922,14 +2921,6 @@ static inline struct request *blk_mq_get_cached_request(struct request_queue *q,
 	return rq;
 }
 
-static void bio_set_ioprio(struct bio *bio)
-{
-	/* Nobody set ioprio so far? Initialize it based on task's nice value */
-	if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) == IOPRIO_CLASS_NONE)
-		bio->bi_ioprio = get_current_ioprio();
-	blkcg_set_ioprio(bio);
-}
-
 /**
  * blk_mq_submit_bio - Create and send a request to block device.
  * @bio: Bio pointer.
@@ -2963,8 +2954,6 @@ void blk_mq_submit_bio(struct bio *bio)
 	if (!bio_integrity_prep(bio))
 		return;
 
-	bio_set_ioprio(bio);
-
 	rq = blk_mq_get_cached_request(q, plug, &bio, nr_segs);
 	if (!rq) {
 		if (!bio)
-- 
2.34.1