No functional changes in this patch, but it allows each bio to
carry a stream ID and disallows merging of bio's with different
stream IDs.
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
block/bio.c | 2 ++
block/blk-merge.c | 14 ++++++++++++++
include/linux/blk_types.h | 17 +++++++++++++++++
3 files changed, 33 insertions(+)
diff --git a/block/bio.c b/block/bio.c
index 888e7801c638..77f4be1f7428 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -595,6 +595,7 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
bio->bi_opf = bio_src->bi_opf;
bio->bi_iter = bio_src->bi_iter;
bio->bi_io_vec = bio_src->bi_io_vec;
+ bio->bi_stream = bio_src->bi_stream;
bio_clone_blkcg_association(bio, bio_src);
}
@@ -678,6 +679,7 @@ struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
bio->bi_opf = bio_src->bi_opf;
bio->bi_iter.bi_sector = bio_src->bi_iter.bi_sector;
bio->bi_iter.bi_size = bio_src->bi_iter.bi_size;
+ bio->bi_stream = bio_src->bi_stream;
switch (bio_op(bio)) {
case REQ_OP_DISCARD:
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 3990ae406341..28998acdd675 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -693,6 +693,13 @@ static struct request *attempt_merge(struct request_queue *q,
return NULL;
/*
+ * Don't allow merge of different streams, or for a stream with
+ * non-stream IO.
+ */
+ if (req->bio->bi_stream != next->bio->bi_stream)
+ return NULL;
+
+ /*
* If we are allowed to merge, then append bio list
* from next to rq and release next. merge_requests_fn
* will have updated segment counts, update sector
@@ -811,6 +818,13 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
!blk_write_same_mergeable(rq->bio, bio))
return false;
+ /*
+ * Don't allow merge of different streams, or for a stream with
+ * non-stream IO.
+ */
+ if (rq->bio->bi_stream != bio->bi_stream)
+ return false;
+
return true;
}
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 61339bc44400..1940876a7fa7 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -36,6 +36,8 @@ struct bio {
unsigned short bi_flags; /* status, etc and bvec pool number */
unsigned short bi_ioprio;
+ unsigned int bi_stream; /* write life time hint */
+
struct bvec_iter bi_iter;
/* Number of segments in this BIO after
@@ -312,4 +314,19 @@ struct blk_rq_stat {
u64 batch;
};
+static inline void bio_set_streamid(struct bio *bio, unsigned int stream)
+{
+ bio->bi_stream = stream;
+}
+
+static inline bool bio_stream_valid(struct bio *bio)
+{
+ return bio->bi_stream != 0;
+}
+
+static inline unsigned int bio_stream(struct bio *bio)
+{
+ return bio->bi_stream;
+}
+
#endif /* __LINUX_BLK_TYPES_H */
--
2.7.4
