[PATCH v3 4/5] dm verity: Fix I/O priority lost when read FEC and hash

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

From: Hongyu Jin <hongyu.jin@xxxxxxxxxx>

To fix this problem, when read FEC and hash from disk, I/O priority are
inconsistent with data block and blocked by other I/O with low I/O
priority.

Make I/O for FEC and hash has same I/O priority with original data I/O.

Co-developed-by: Yibin Ding <yibin.ding@xxxxxxxxxx>
Signed-off-by: Yibin Ding <yibin.ding@xxxxxxxxxx>
Signed-off-by: Hongyu Jin <hongyu.jin@xxxxxxxxxx>
---
 drivers/md/dm-verity-fec.c    | 3 ++-
 drivers/md/dm-verity-target.c | 8 ++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c
index 715173cbf0ee..6a5a679e7e8a 100644
--- a/drivers/md/dm-verity-fec.c
+++ b/drivers/md/dm-verity-fec.c
@@ -209,6 +209,7 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
 	u8 *bbuf, *rs_block;
 	u8 want_digest[HASH_MAX_DIGESTSIZE];
 	unsigned int n, k;
+	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
 
 	if (neras)
 		*neras = 0;
@@ -247,7 +248,7 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io,
 			bufio = v->bufio;
 		}
 
-		bbuf = dm_bufio_read(bufio, block, &buf, IOPRIO_DEFAULT);
+		bbuf = dm_bufio_read(bufio, block, &buf, bio_prio(bio));
 		if (IS_ERR(bbuf)) {
 			DMWARN_LIMIT("%s: FEC %llu: read failed (%llu): %ld",
 				     v->data_dev->name,
diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index 0038e168f3d7..8c911b6722ce 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -51,6 +51,7 @@ static DEFINE_STATIC_KEY_FALSE(use_tasklet_enabled);
 struct dm_verity_prefetch_work {
 	struct work_struct work;
 	struct dm_verity *v;
+	unsigned short ioprio;
 	sector_t block;
 	unsigned int n_blocks;
 };
@@ -293,6 +294,7 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io,
 	int r;
 	sector_t hash_block;
 	unsigned int offset;
+	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
 
 	verity_hash_at_level(v, block, level, &hash_block, &offset);
 
@@ -307,7 +309,7 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io,
 			return -EAGAIN;
 		}
 	} else
-		data = dm_bufio_read(v->bufio, hash_block, &buf, IOPRIO_DEFAULT);
+		data = dm_bufio_read(v->bufio, hash_block, &buf, bio_prio(bio));
 
 	if (IS_ERR(data))
 		return PTR_ERR(data);
@@ -717,7 +719,7 @@ static void verity_prefetch_io(struct work_struct *work)
 		}
 no_prefetch_cluster:
 		dm_bufio_prefetch(v->bufio, hash_block_start,
-				  hash_block_end - hash_block_start + 1, IOPRIO_DEFAULT);
+				  hash_block_end - hash_block_start + 1, pw->ioprio);
 	}
 
 	kfree(pw);
@@ -728,6 +730,7 @@ static void verity_submit_prefetch(struct dm_verity *v, struct dm_verity_io *io)
 	sector_t block = io->block;
 	unsigned int n_blocks = io->n_blocks;
 	struct dm_verity_prefetch_work *pw;
+	struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
 
 	if (v->validated_blocks) {
 		while (n_blocks && test_bit(block, v->validated_blocks)) {
@@ -751,6 +754,7 @@ static void verity_submit_prefetch(struct dm_verity *v, struct dm_verity_io *io)
 	pw->v = v;
 	pw->block = block;
 	pw->n_blocks = n_blocks;
+	pw->ioprio = bio_prio(bio);
 	queue_work(v->verify_wq, &pw->work);
 }
 
-- 
2.34.1