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authorJens Axboe <axboe@fb.com>2015-09-03 19:28:20 +0300
committerJens Axboe <axboe@fb.com>2015-09-03 10:33:09 -0600
commit5e7c4274a70aa2d6f485996d0ca1dad52d0039ca (patch)
treedce51421028d162af78514b631dc75a6be92cf11 /include
parent5fdb7e1b976dc9d18aff8c711e51d17c4c324a0e (diff)
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block: Check for gaps on front and back merges
We are checking for gaps to previous bio_vec, which can only detect back merges gaps. Moreover, at the point where we check for a gap, we don't know if we will attempt a back or a front merge. Thus, check for gap to prev in a back merge attempt and check for a gap to next in a front merge attempt. Signed-off-by: Jens Axboe <axboe@fb.com> [sagig: Minor rename change] Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Diffstat (limited to 'include')
-rw-r--r--include/linux/blkdev.h20
1 files changed, 20 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index a622f270f09e..2ff94def041e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1368,6 +1368,26 @@ static inline bool bvec_gap_to_prev(struct request_queue *q,
((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
}
+static inline bool bio_will_gap(struct request_queue *q, struct bio *prev,
+ struct bio *next)
+{
+ if (!bio_has_data(prev))
+ return false;
+
+ return bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1],
+ next->bi_io_vec[0].bv_offset);
+}
+
+static inline bool req_gap_back_merge(struct request *req, struct bio *bio)
+{
+ return bio_will_gap(req->q, req->biotail, bio);
+}
+
+static inline bool req_gap_front_merge(struct request *req, struct bio *bio)
+{
+ return bio_will_gap(req->q, bio, req->bio);
+}
+
struct work_struct;
int kblockd_schedule_work(struct work_struct *work);
int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);