xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

block: add support for limiting gaps in SG lists

Browse Source 
Another restriction inherited for NVMe - those devices don't support
SG lists that have "gaps" in them. Gaps refers to cases where the
previous SG entry doesn't end on a page boundary. For NVMe, all SG
entries must start at offset 0 (except the first) and end on a page
boundary (except the last).

Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Jens Axboe
2014-06-24 16:22:24 -06:00
parent 3a4b0eda8e
commit 66cb45aa41
4 changed files with 28 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
block/blk-merge.c
View File

@@ -568,6 +568,8 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
{
struct request_queue *q = rq->q;
if (!rq_mergeable(rq) || !bio_mergeable(bio))
return false;
@@ -591,6 +593,14 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
!blk_write_same_mergeable(rq->bio, bio))
return false;
if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS)) {
struct bio_vec *bprev;
bprev = &rq->biotail->bi_io_vec[bio->bi_vcnt - 1];
if (bvec_gap_to_prev(bprev, bio->bi_io_vec[0].bv_offset))
return false;
}
return true;
}