block: Fix where bio IO priority gets set

Commit 82b74cac2849 ("blk-ioprio: Convert from rqos policy to direct
call") pushed setting bio I/O priority down into blk_mq_submit_bio()
-- which is too low within block core's submit_bio() because it
skips setting I/O priority for block drivers that implement
fops->submit_bio() (e.g. DM, MD, etc).

Fix this by moving bio_set_ioprio() up from blk-mq.c to blk-core.c and
call it from submit_bio().  This ensures all block drivers call
bio_set_ioprio() during initial bio submission.

Fixes: a78418e6a04c ("block: Always initialize bio IO priority on submit")
Co-developed-by: Yibin Ding <yibin.ding@unisoc.com>
Signed-off-by: Yibin Ding <yibin.ding@unisoc.com>
Signed-off-by: Hongyu Jin <hongyu.jin@unisoc.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
[snitzer: revised commit header]
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240130202638.62600-2-snitzer@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 10 insertions, 0 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 11342af420d0..de771093b526 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;
 
@@ -833,6 +834,14 @@ end_io:
 }
 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
@@ -855,6 +864,7 @@ 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);