block: Remove bio->bi_ioc

bio->bi_ioc is never set so always NULL. Remove references to it in
bio_disassociate_task() and in rq_ioc() and delete this field from
struct bio. With this change, rq_ioc() always returns
current->io_context without the need for a bio argument. Further
simplify the code and make it more readable by also removing this
helper, which also allows to simplify blk_mq_sched_assign_ioc() by
removing its bio argument.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Damien Le Moal 2018-11-20 10:52:34 +09:00 committed by Jens Axboe
parent 23464f8c34
commit e2b3fa5af7
7 changed files with 7 additions and 28 deletions

View File

@ -2027,10 +2027,6 @@ int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg)
*/
void bio_disassociate_task(struct bio *bio)
{
if (bio->bi_ioc) {
put_io_context(bio->bi_ioc);
bio->bi_ioc = NULL;
}
if (bio->bi_css) {
css_put(bio->bi_css);
bio->bi_css = NULL;

View File

@ -813,7 +813,7 @@ unsigned int blk_plug_queued_count(struct request_queue *q)
void blk_init_request_from_bio(struct request *req, struct bio *bio)
{
struct io_context *ioc = rq_ioc(bio);
struct io_context *ioc = current->io_context;
if (bio->bi_opf & REQ_RAHEAD)
req->cmd_flags |= REQ_FAILFAST_MASK;

View File

@ -31,10 +31,10 @@ void blk_mq_sched_free_hctx_data(struct request_queue *q,
}
EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data);
void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio)
void blk_mq_sched_assign_ioc(struct request *rq)
{
struct request_queue *q = rq->q;
struct io_context *ioc = rq_ioc(bio);
struct io_context *ioc = current->io_context;
struct io_cq *icq;
spin_lock_irq(&q->queue_lock);

View File

@ -8,7 +8,7 @@
void blk_mq_sched_free_hctx_data(struct request_queue *q,
void (*exit)(struct blk_mq_hw_ctx *));
void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio);
void blk_mq_sched_assign_ioc(struct request *rq);
void blk_mq_sched_request_inserted(struct request *rq);
bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,

View File

@ -389,8 +389,8 @@ static struct request *blk_mq_get_request(struct request_queue *q,
if (!op_is_flush(data->cmd_flags)) {
rq->elv.icq = NULL;
if (e && e->type->ops.prepare_request) {
if (e->type->icq_cache && rq_ioc(bio))
blk_mq_sched_assign_ioc(rq, bio);
if (e->type->icq_cache)
blk_mq_sched_assign_ioc(rq);
e->type->ops.prepare_request(rq, bio);
rq->rq_flags |= RQF_ELVPRIV;

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@ -254,22 +254,6 @@ void ioc_clear_queue(struct request_queue *q);
int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
/**
* rq_ioc - determine io_context for request allocation
* @bio: request being allocated is for this bio (can be %NULL)
*
* Determine io_context to use for request allocation for @bio. May return
* %NULL if %current->io_context doesn't exist.
*/
static inline struct io_context *rq_ioc(struct bio *bio)
{
#ifdef CONFIG_BLK_CGROUP
if (bio && bio->bi_ioc)
return bio->bi_ioc;
#endif
return current->io_context;
}
/**
* create_io_context - try to create task->io_context
* @gfp_mask: allocation mask

View File

@ -174,10 +174,9 @@ struct bio {
void *bi_private;
#ifdef CONFIG_BLK_CGROUP
/*
* Optional ioc and css associated with this bio. Put on bio
* Optional css associated with this bio. Put on bio
* release. Read comment on top of bio_associate_current().
*/
struct io_context *bi_ioc;
struct cgroup_subsys_state *bi_css;
struct blkcg_gq *bi_blkg;
struct bio_issue bi_issue;