diff options
author | Tejun Heo <tj@kernel.org> | 2012-02-08 03:19:38 -0500 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2012-02-08 03:19:38 -0500 |
commit | 050c8ea80e3e90019d9e981c6a117ef614e882ed (patch) | |
tree | e1c53f17a93ba48b9aedb0c1560dfb022733845f | |
parent | 4e8670e26135d8fbfd5e084fddc1a8ed9f8eb4cb (diff) |
block: separate out blk_rq_merge_ok() and blk_try_merge() from elevator functions
blk_rq_merge_ok() is the elevator-neutral part of merge eligibility
test. blk_try_merge() determines merge direction and expects the
caller to have tested elv_rq_merge_ok() previously.
elv_rq_merge_ok() now wraps blk_rq_merge_ok() and then calls
elv_iosched_allow_merge(). elv_try_merge() is removed and the two
callers are updated to call elv_rq_merge_ok() explicitly followed by
blk_try_merge(). While at it, make rq_merge_ok() functions return
bool.
This is to prepare for plug merge update and doesn't introduce any
behavior change.
This is based on Jens' patch to skip elevator_allow_merge_fn() from
plug merge.
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <4F16F3CA.90904@kernel.dk>
Original-patch-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r-- | block/blk-core.c | 4 | ||||
-rw-r--r-- | block/blk-merge.c | 37 | ||||
-rw-r--r-- | block/blk.h | 2 | ||||
-rw-r--r-- | block/elevator.c | 55 | ||||
-rw-r--r-- | include/linux/elevator.h | 3 |
5 files changed, 46 insertions, 55 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 532b3a21b383..fa697bf691eb 100644 --- a/block/blk-core.c +++ b/block/blk-core.c | |||
@@ -1282,10 +1282,10 @@ static bool attempt_plug_merge(struct request_queue *q, struct bio *bio, | |||
1282 | 1282 | ||
1283 | (*request_count)++; | 1283 | (*request_count)++; |
1284 | 1284 | ||
1285 | if (rq->q != q) | 1285 | if (rq->q != q || !elv_rq_merge_ok(rq, bio)) |
1286 | continue; | 1286 | continue; |
1287 | 1287 | ||
1288 | el_ret = elv_try_merge(rq, bio); | 1288 | el_ret = blk_try_merge(rq, bio); |
1289 | if (el_ret == ELEVATOR_BACK_MERGE) { | 1289 | if (el_ret == ELEVATOR_BACK_MERGE) { |
1290 | ret = bio_attempt_back_merge(q, rq, bio); | 1290 | ret = bio_attempt_back_merge(q, rq, bio); |
1291 | if (ret) | 1291 | if (ret) |
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, | |||
471 | { | 471 | { |
472 | return attempt_merge(q, rq, next); | 472 | return attempt_merge(q, rq, next); |
473 | } | 473 | } |
474 | |||
475 | bool blk_rq_merge_ok(struct request *rq, struct bio *bio) | ||
476 | { | ||
477 | if (!rq_mergeable(rq)) | ||
478 | return false; | ||
479 | |||
480 | /* don't merge file system requests and discard requests */ | ||
481 | if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD)) | ||
482 | return false; | ||
483 | |||
484 | /* don't merge discard requests and secure discard requests */ | ||
485 | if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE)) | ||
486 | return false; | ||
487 | |||
488 | /* different data direction or already started, don't merge */ | ||
489 | if (bio_data_dir(bio) != rq_data_dir(rq)) | ||
490 | return false; | ||
491 | |||
492 | /* must be same device and not a special request */ | ||
493 | if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special) | ||
494 | return false; | ||
495 | |||
496 | /* only merge integrity protected bio into ditto rq */ | ||
497 | if (bio_integrity(bio) != blk_integrity_rq(rq)) | ||
498 | return false; | ||
499 | |||
500 | return true; | ||
501 | } | ||
502 | |||
503 | int blk_try_merge(struct request *rq, struct bio *bio) | ||
504 | { | ||
505 | if (blk_rq_pos(rq) + blk_rq_sectors(rq) == bio->bi_sector) | ||
506 | return ELEVATOR_BACK_MERGE; | ||
507 | else if (blk_rq_pos(rq) - bio_sectors(bio) == bio->bi_sector) | ||
508 | return ELEVATOR_FRONT_MERGE; | ||
509 | return ELEVATOR_NO_MERGE; | ||
510 | } | ||
diff --git a/block/blk.h b/block/blk.h index 7efd772336de..9c12f80882b0 100644 --- a/block/blk.h +++ b/block/blk.h | |||
@@ -137,6 +137,8 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq, | |||
137 | struct request *next); | 137 | struct request *next); |
138 | void blk_recalc_rq_segments(struct request *rq); | 138 | void blk_recalc_rq_segments(struct request *rq); |
139 | void blk_rq_set_mixed_merge(struct request *rq); | 139 | void blk_rq_set_mixed_merge(struct request *rq); |
140 | bool blk_rq_merge_ok(struct request *rq, struct bio *bio); | ||
141 | int blk_try_merge(struct request *rq, struct bio *bio); | ||
140 | 142 | ||
141 | void blk_queue_congestion_threshold(struct request_queue *q); | 143 | void blk_queue_congestion_threshold(struct request_queue *q); |
142 | 144 | ||
diff --git a/block/elevator.c b/block/elevator.c index 91e18f8af9be..f016855a46b0 100644 --- a/block/elevator.c +++ b/block/elevator.c | |||
@@ -70,39 +70,9 @@ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio) | |||
70 | /* | 70 | /* |
71 | * can we safely merge with this request? | 71 | * can we safely merge with this request? |
72 | */ | 72 | */ |
73 | int elv_rq_merge_ok(struct request *rq, struct bio *bio) | 73 | bool elv_rq_merge_ok(struct request *rq, struct bio *bio) |
74 | { | 74 | { |
75 | if (!rq_mergeable(rq)) | 75 | if (!blk_rq_merge_ok(rq, bio)) |
76 | return 0; | ||
77 | |||
78 | /* | ||
79 | * Don't merge file system requests and discard requests | ||
80 | */ | ||
81 | if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD)) | ||
82 | return 0; | ||
83 | |||
84 | /* | ||
85 | * Don't merge discard requests and secure discard requests | ||
86 | */ | ||
87 | if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE)) | ||
88 | return 0; | ||
89 | |||
90 | /* | ||
91 | * different data direction or already started, don't merge | ||
92 | */ | ||
93 | if (bio_data_dir(bio) != rq_data_dir(rq)) | ||
94 | return 0; | ||
95 | |||
96 | /* | ||
97 | * must be same device and not a special request | ||
98 | */ | ||
99 | if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special) | ||
100 | return 0; | ||
101 | |||
102 | /* | ||
103 | * only merge integrity protected bio into ditto rq | ||
104 | */ | ||
105 | if (bio_integrity(bio) != blk_integrity_rq(rq)) | ||
106 | return 0; | 76 | return 0; |
107 | 77 | ||
108 | if (!elv_iosched_allow_merge(rq, bio)) | 78 | if (!elv_iosched_allow_merge(rq, bio)) |
@@ -112,23 +82,6 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio) | |||
112 | } | 82 | } |
113 | EXPORT_SYMBOL(elv_rq_merge_ok); | 83 | EXPORT_SYMBOL(elv_rq_merge_ok); |
114 | 84 | ||
115 | int elv_try_merge(struct request *__rq, struct bio *bio) | ||
116 | { | ||
117 | int ret = ELEVATOR_NO_MERGE; | ||
118 | |||
119 | /* | ||
120 | * we can merge and sequence is ok, check if it's possible | ||
121 | */ | ||
122 | if (elv_rq_merge_ok(__rq, bio)) { | ||
123 | if (blk_rq_pos(__rq) + blk_rq_sectors(__rq) == bio->bi_sector) | ||
124 | ret = ELEVATOR_BACK_MERGE; | ||
125 | else if (blk_rq_pos(__rq) - bio_sectors(bio) == bio->bi_sector) | ||
126 | ret = ELEVATOR_FRONT_MERGE; | ||
127 | } | ||
128 | |||
129 | return ret; | ||
130 | } | ||
131 | |||
132 | static struct elevator_type *elevator_find(const char *name) | 85 | static struct elevator_type *elevator_find(const char *name) |
133 | { | 86 | { |
134 | struct elevator_type *e; | 87 | struct elevator_type *e; |
@@ -478,8 +431,8 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) | |||
478 | /* | 431 | /* |
479 | * First try one-hit cache. | 432 | * First try one-hit cache. |
480 | */ | 433 | */ |
481 | if (q->last_merge) { | 434 | if (q->last_merge && elv_rq_merge_ok(q->last_merge, bio)) { |
482 | ret = elv_try_merge(q->last_merge, bio); | 435 | ret = blk_try_merge(q->last_merge, bio); |
483 | if (ret != ELEVATOR_NO_MERGE) { | 436 | if (ret != ELEVATOR_NO_MERGE) { |
484 | *req = q->last_merge; | 437 | *req = q->last_merge; |
485 | return ret; | 438 | return ret; |
diff --git a/include/linux/elevator.h b/include/linux/elevator.h index c24f3d7fbf1e..d6dfb65c8885 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h | |||
@@ -122,7 +122,6 @@ extern void elv_dispatch_add_tail(struct request_queue *, struct request *); | |||
122 | extern void elv_add_request(struct request_queue *, struct request *, int); | 122 | extern void elv_add_request(struct request_queue *, struct request *, int); |
123 | extern void __elv_add_request(struct request_queue *, struct request *, int); | 123 | extern void __elv_add_request(struct request_queue *, struct request *, int); |
124 | extern int elv_merge(struct request_queue *, struct request **, struct bio *); | 124 | extern int elv_merge(struct request_queue *, struct request **, struct bio *); |
125 | extern int elv_try_merge(struct request *, struct bio *); | ||
126 | extern void elv_merge_requests(struct request_queue *, struct request *, | 125 | extern void elv_merge_requests(struct request_queue *, struct request *, |
127 | struct request *); | 126 | struct request *); |
128 | extern void elv_merged_request(struct request_queue *, struct request *, int); | 127 | extern void elv_merged_request(struct request_queue *, struct request *, int); |
@@ -155,7 +154,7 @@ extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t); | |||
155 | extern int elevator_init(struct request_queue *, char *); | 154 | extern int elevator_init(struct request_queue *, char *); |
156 | extern void elevator_exit(struct elevator_queue *); | 155 | extern void elevator_exit(struct elevator_queue *); |
157 | extern int elevator_change(struct request_queue *, const char *); | 156 | extern int elevator_change(struct request_queue *, const char *); |
158 | extern int elv_rq_merge_ok(struct request *, struct bio *); | 157 | extern bool elv_rq_merge_ok(struct request *, struct bio *); |
159 | 158 | ||
160 | /* | 159 | /* |
161 | * Helper functions. | 160 | * Helper functions. |