block: remove request ref_count

This reference count has been around since before git history, but the only
place where it's used is in blk_execute_rq, and ther it is entirely useless
as it is incremented before submitting the request and decremented in the
end_io handler before waking up the submitter thread.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2013-10-04 06:49:11 -07:00 committed by Jens Axboe
parent 5953316dbf
commit 71fe07d040
3 changed files with 0 additions and 12 deletions

View File

@ -145,7 +145,6 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
rq->cmd = rq->__cmd;
rq->cmd_len = BLK_MAX_CDB;
rq->tag = -1;
rq->ref_count = 1;
rq->start_time = jiffies;
set_start_time_ns(rq);
rq->part = NULL;
@ -1272,8 +1271,6 @@ void __blk_put_request(struct request_queue *q, struct request *req)
{
if (unlikely(!q))
return;
if (unlikely(--req->ref_count))
return;
blk_pm_put_request(req);

View File

@ -24,7 +24,6 @@ static void blk_end_sync_rq(struct request *rq, int error)
struct completion *waiting = rq->end_io_data;
rq->end_io_data = NULL;
__blk_put_request(rq->q, rq);
/*
* complete last, if this is a stack request the process (and thus
@ -103,12 +102,6 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
int err = 0;
unsigned long hang_check;
/*
* we need an extra reference to the request, so we can look at
* it after io completion
*/
rq->ref_count++;
if (!rq->sense) {
memset(sense, 0, sizeof(sense));
rq->sense = sense;

View File

@ -160,8 +160,6 @@ struct request {
unsigned short ioprio;
int ref_count;
void *special; /* opaque pointer available for LLD use */
char *buffer; /* kaddr of the current segment if available */