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authorIngo Molnar <mingo@elte.hu>2012-03-14 07:44:11 +0100
committerIngo Molnar <mingo@elte.hu>2012-03-14 07:44:11 +0100
commitcd593accdcc27ccbe6498d9ad1c2b6cc8e1d830d (patch)
tree9424d3ac86e753706cc6c3d7e6072d2a73711e29 /block/blk-merge.c
parent11b91d6fe7272452c999573bab33c15c2f03dc31 (diff)
parentfde7d9049e55ab85a390be7f415d74c9f62dd0f9 (diff)
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Merge tag 'v3.3-rc7' into x86/mce
Merge reason: Update from an ancient -rc1 base to an almost-final stable kernel. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'block/blk-merge.c')
-rw-r--r--block/blk-merge.c37
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;
+}