[PATCH v16 02/11] block: add a bi_write_stream field

[Kanchan Joshi]

From: Christoph Hellwig <hch at lst.de>

Add the ability to pass a write stream for placement control in the bio.
The new field fits in an existing hole, so does not change the size of
the struct.

Reviewed-by: Hannes Reinecke <hare at suse.de>
Reviewed-by: Nitesh Shetty <nj.shetty at samsung.com>
Signed-off-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Keith Busch <kbusch at kernel.org>
Signed-off-by: Kanchan Joshi <joshi.k at samsung.com>
---
 block/bio.c                 | 2 ++
 block/blk-crypto-fallback.c | 1 +
 block/blk-merge.c           | 4 ++++
 include/linux/blk_types.h   | 1 +
 4 files changed, 8 insertions(+)

diff --git a/block/bio.c b/block/bio.c
index 4e6c85a33d74..1e42aefc7377 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -251,6 +251,7 @@ void bio_init(struct bio *bio, struct block_device *bdev, struct bio_vec *table,
 	bio->bi_flags = 0;
 	bio->bi_ioprio = 0;
 	bio->bi_write_hint = 0;
+	bio->bi_write_stream = 0;
 	bio->bi_status = 0;
 	bio->bi_iter.bi_sector = 0;
 	bio->bi_iter.bi_size = 0;
@@ -827,6 +828,7 @@ static int __bio_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp)
 	bio_set_flag(bio, BIO_CLONED);
 	bio->bi_ioprio = bio_src->bi_ioprio;
 	bio->bi_write_hint = bio_src->bi_write_hint;
+	bio->bi_write_stream = bio_src->bi_write_stream;
 	bio->bi_iter = bio_src->bi_iter;
 
 	if (bio->bi_bdev) {
diff --git a/block/blk-crypto-fallback.c b/block/blk-crypto-fallback.c
index f154be0b575a..005c9157ffb3 100644
--- a/block/blk-crypto-fallback.c
+++ b/block/blk-crypto-fallback.c
@@ -173,6 +173,7 @@ static struct bio *blk_crypto_fallback_clone_bio(struct bio *bio_src)
 		bio_set_flag(bio, BIO_REMAPPED);
 	bio->bi_ioprio		= bio_src->bi_ioprio;
 	bio->bi_write_hint	= bio_src->bi_write_hint;
+	bio->bi_write_stream	= bio_src->bi_write_stream;
 	bio->bi_iter.bi_sector	= bio_src->bi_iter.bi_sector;
 	bio->bi_iter.bi_size	= bio_src->bi_iter.bi_size;
 
diff --git a/block/blk-merge.c b/block/blk-merge.c
index fdd4efb54c6c..782308b73b53 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -832,6 +832,8 @@ static struct request *attempt_merge(struct request_queue *q,
 
 	if (req->bio->bi_write_hint != next->bio->bi_write_hint)
 		return NULL;
+	if (req->bio->bi_write_stream != next->bio->bi_write_stream)
+		return NULL;
 	if (req->bio->bi_ioprio != next->bio->bi_ioprio)
 		return NULL;
 	if (!blk_atomic_write_mergeable_rqs(req, next))
@@ -953,6 +955,8 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 		return false;
 	if (rq->bio->bi_write_hint != bio->bi_write_hint)
 		return false;
+	if (rq->bio->bi_write_stream != bio->bi_write_stream)
+		return false;
 	if (rq->bio->bi_ioprio != bio->bi_ioprio)
 		return false;
 	if (blk_atomic_write_mergeable_rq_bio(rq, bio) == false)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 5a46067e85b1..f38425338c3f 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -220,6 +220,7 @@ struct bio {
 	unsigned short		bi_flags;	/* BIO_* below */
 	unsigned short		bi_ioprio;
 	enum rw_hint		bi_write_hint;
+	u8			bi_write_stream;
 	blk_status_t		bi_status;
 	atomic_t		__bi_remaining;
 
-- 
2.25.1