diff options
author | Arnd Bergmann <arnd@arndb.de> | 2012-02-28 12:39:56 +0000 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2012-02-28 12:40:01 +0000 |
commit | 4d8cfec692e988b844dcaeaeb76b5780b7ef9d28 (patch) | |
tree | 67d43adab2afd18a74d08f347e3676ae1a64193f /block/blk-merge.c | |
parent | a3a3c4664184f86ef964323d106c62158e2b3f25 (diff) | |
parent | 1d8c38c3d1b48eeb9cfaa42a8be13a1423569eb2 (diff) |
Merge branch 'cleanup-3.4' of git://github.com/hzhuang1/linux into next/cleanup
* 'cleanup-3.4' of git://github.com/hzhuang1/linux: (2 commits)
rtc: sa1100: remove verification code of alarm
rtc: sa1100: remove periodic code
(update to v3.3-rc5)
Diffstat (limited to 'block/blk-merge.c')
-rw-r--r-- | block/blk-merge.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c index cfcc37cb222b..160035f54882 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -471,3 +471,40 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq, { return attempt_merge(q, rq, next); } + +bool blk_rq_merge_ok(struct request *rq, struct bio *bio) +{ + if (!rq_mergeable(rq)) + return false; + + /* don't merge file system requests and discard requests */ + if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD)) + return false; + + /* don't merge discard requests and secure discard requests */ + if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE)) + return false; + + /* different data direction or already started, don't merge */ + if (bio_data_dir(bio) != rq_data_dir(rq)) + return false; + + /* must be same device and not a special request */ + if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special) + return false; + + /* only merge integrity protected bio into ditto rq */ + if (bio_integrity(bio) != blk_integrity_rq(rq)) + return false; + + return true; +} + +int blk_try_merge(struct request *rq, struct bio *bio) +{ + if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_sector) + return ELEVATOR_BACK_MERGE; + else if (blk_rq_pos(rq) - bio_sectors(bio) == bio->bi_sector) + return ELEVATOR_FRONT_MERGE; + return ELEVATOR_NO_MERGE; +} |