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block: Move bio merge related functions into blk-merge.c 

It's better to move bio merge related functions into blk-merge.c,
which contains all merge related functions.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Baolin Wang 2020-08-28 10:52:54 +08:00 committed by Jens Axboe
parent 339b5a25c2
commit 8e756373d7
2 changed files with 157 additions and 156 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

156
block/blk-core.c
View File

@ -643,162 +643,6 @@ void blk_put_request(struct request *req)
}
EXPORT_SYMBOL(blk_put_request);
static void blk_account_io_merge_bio(struct request *req)
{
if (!blk_do_io_stat(req))
return;
part_stat_lock();
part_stat_inc(req->part, merges[op_stat_group(req_op(req))]);
part_stat_unlock();
}
bool bio_attempt_back_merge(struct request *req, struct bio *bio,
unsigned int nr_segs)
{
const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
if (!ll_back_merge_fn(req, bio, nr_segs))
return false;
trace_block_bio_backmerge(req->q, req, bio);
rq_qos_merge(req->q, req, bio);
if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
blk_rq_set_mixed_merge(req);
req->biotail->bi_next = bio;
req->biotail = bio;
req->__data_len += bio->bi_iter.bi_size;
bio_crypt_free_ctx(bio);
blk_account_io_merge_bio(req);
return true;
}
bool bio_attempt_front_merge(struct request *req, struct bio *bio,
unsigned int nr_segs)
{
const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
if (!ll_front_merge_fn(req, bio, nr_segs))
return false;
trace_block_bio_frontmerge(req->q, req, bio);
rq_qos_merge(req->q, req, bio);
if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
blk_rq_set_mixed_merge(req);
bio->bi_next = req->bio;
req->bio = bio;
req->__sector = bio->bi_iter.bi_sector;
req->__data_len += bio->bi_iter.bi_size;
bio_crypt_do_front_merge(req, bio);
blk_account_io_merge_bio(req);
return true;
}
bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
struct bio *bio)
{
unsigned short segments = blk_rq_nr_discard_segments(req);
if (segments >= queue_max_discard_segments(q))
goto no_merge;
if (blk_rq_sectors(req) + bio_sectors(bio) >
blk_rq_get_max_sectors(req, blk_rq_pos(req)))
goto no_merge;
rq_qos_merge(q, req, bio);
req->biotail->bi_next = bio;
req->biotail = bio;
req->__data_len += bio->bi_iter.bi_size;
req->nr_phys_segments = segments + 1;
blk_account_io_merge_bio(req);
return true;
no_merge:
req_set_nomerge(q, req);
return false;
}
/**
* blk_attempt_plug_merge - try to merge with %current's plugged list
* @q: request_queue new bio is being queued at
* @bio: new bio being queued
* @nr_segs: number of segments in @bio
* @same_queue_rq: pointer to &struct request that gets filled in when
* another request associated with @q is found on the plug list
* (optional, may be %NULL)
*
* Determine whether @bio being queued on @q can be merged with a request
* on %current's plugged list. Returns %true if merge was successful,
* otherwise %false.
*
* Plugging coalesces IOs from the same issuer for the same purpose without
* going through @q->queue_lock. As such it's more of an issuing mechanism
* than scheduling, and the request, while may have elvpriv data, is not
* added on the elevator at this point. In addition, we don't have
* reliable access to the elevator outside queue lock. Only check basic
* merging parameters without querying the elevator.
*
* Caller must ensure !blk_queue_nomerges(q) beforehand.
*/
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
unsigned int nr_segs, struct request **same_queue_rq)
{
struct blk_plug *plug;
struct request *rq;
struct list_head *plug_list;
plug = blk_mq_plug(q, bio);
if (!plug)
return false;
plug_list = &plug->mq_list;
list_for_each_entry_reverse(rq, plug_list, queuelist) {
bool merged = false;
if (rq->q == q && same_queue_rq) {
/*
* Only blk-mq multiple hardware queues case checks the
* rq in the same queue, there should be only one such
* rq in a queue
**/
*same_queue_rq = rq;
}
if (rq->q != q || !blk_rq_merge_ok(rq, bio))
continue;
switch (blk_try_merge(rq, bio)) {
case ELEVATOR_BACK_MERGE:
merged = bio_attempt_back_merge(rq, bio, nr_segs);
break;
case ELEVATOR_FRONT_MERGE:
merged = bio_attempt_front_merge(rq, bio, nr_segs);
break;
case ELEVATOR_DISCARD_MERGE:
merged = bio_attempt_discard_merge(q, rq, bio);
break;
default:
break;
}
if (merged)
return true;
}
return false;
}
static void handle_bad_sector(struct bio *bio, sector_t maxsector)
{
char b[BDEVNAME_SIZE];

157
block/blk-merge.c
View File

@ -11,6 +11,7 @@
#include <trace/events/block.h>
#include "blk.h"
#include "blk-rq-qos.h"
static inline bool bio_will_gap(struct request_queue *q,
struct request *prev_rq, struct bio *prev, struct bio *next)
@ -895,3 +896,159 @@ enum elv_merge blk_try_merge(struct request *rq, struct bio *bio)
return ELEVATOR_FRONT_MERGE;
return ELEVATOR_NO_MERGE;
}
static void blk_account_io_merge_bio(struct request *req)
{
if (!blk_do_io_stat(req))
return;
part_stat_lock();
part_stat_inc(req->part, merges[op_stat_group(req_op(req))]);
part_stat_unlock();
}
bool bio_attempt_back_merge(struct request *req, struct bio *bio,
unsigned int nr_segs)
{
const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
if (!ll_back_merge_fn(req, bio, nr_segs))
return false;
trace_block_bio_backmerge(req->q, req, bio);
rq_qos_merge(req->q, req, bio);
if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
blk_rq_set_mixed_merge(req);
req->biotail->bi_next = bio;
req->biotail = bio;
req->__data_len += bio->bi_iter.bi_size;
bio_crypt_free_ctx(bio);
blk_account_io_merge_bio(req);
return true;
}
bool bio_attempt_front_merge(struct request *req, struct bio *bio,
unsigned int nr_segs)
{
const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
if (!ll_front_merge_fn(req, bio, nr_segs))
return false;
trace_block_bio_frontmerge(req->q, req, bio);
rq_qos_merge(req->q, req, bio);
if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
blk_rq_set_mixed_merge(req);
bio->bi_next = req->bio;
req->bio = bio;
req->__sector = bio->bi_iter.bi_sector;
req->__data_len += bio->bi_iter.bi_size;
bio_crypt_do_front_merge(req, bio);
blk_account_io_merge_bio(req);
return true;
}
bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
struct bio *bio)
{
unsigned short segments = blk_rq_nr_discard_segments(req);
if (segments >= queue_max_discard_segments(q))
goto no_merge;
if (blk_rq_sectors(req) + bio_sectors(bio) >
blk_rq_get_max_sectors(req, blk_rq_pos(req)))
goto no_merge;
rq_qos_merge(q, req, bio);
req->biotail->bi_next = bio;
req->biotail = bio;
req->__data_len += bio->bi_iter.bi_size;
req->nr_phys_segments = segments + 1;
blk_account_io_merge_bio(req);
return true;
no_merge:
req_set_nomerge(q, req);
return false;
}
/**
* blk_attempt_plug_merge - try to merge with %current's plugged list
* @q: request_queue new bio is being queued at
* @bio: new bio being queued
* @nr_segs: number of segments in @bio
* @same_queue_rq: pointer to &struct request that gets filled in when
* another request associated with @q is found on the plug list
* (optional, may be %NULL)
*
* Determine whether @bio being queued on @q can be merged with a request
* on %current's plugged list. Returns %true if merge was successful,
* otherwise %false.
*
* Plugging coalesces IOs from the same issuer for the same purpose without
* going through @q->queue_lock. As such it's more of an issuing mechanism
* than scheduling, and the request, while may have elvpriv data, is not
* added on the elevator at this point. In addition, we don't have
* reliable access to the elevator outside queue lock. Only check basic
* merging parameters without querying the elevator.
*
* Caller must ensure !blk_queue_nomerges(q) beforehand.
*/
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
unsigned int nr_segs, struct request **same_queue_rq)
{
struct blk_plug *plug;
struct request *rq;
struct list_head *plug_list;
plug = blk_mq_plug(q, bio);
if (!plug)
return false;
plug_list = &plug->mq_list;
list_for_each_entry_reverse(rq, plug_list, queuelist) {
bool merged = false;
if (rq->q == q && same_queue_rq) {
/*
* Only blk-mq multiple hardware queues case checks the
* rq in the same queue, there should be only one such
* rq in a queue
**/
*same_queue_rq = rq;
}
if (rq->q != q || !blk_rq_merge_ok(rq, bio))
continue;
switch (blk_try_merge(rq, bio)) {
case ELEVATOR_BACK_MERGE:
merged = bio_attempt_back_merge(rq, bio, nr_segs);
break;
case ELEVATOR_FRONT_MERGE:
merged = bio_attempt_front_merge(rq, bio, nr_segs);
break;
case ELEVATOR_DISCARD_MERGE:
merged = bio_attempt_discard_merge(q, rq, bio);
break;
default:
break;
}
if (merged)
return true;
}
return false;
}