diff --git a/block/blk-core.c b/block/blk-core.c index b2d0fcd8f87f..991c1d6ef245 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -696,7 +696,7 @@ static inline void blk_free_request(struct request_queue *q, struct request *rq) } static struct request * -blk_alloc_request(struct request_queue *q, struct io_cq *icq, +blk_alloc_request(struct request_queue *q, struct bio *bio, struct io_cq *icq, unsigned int flags, gfp_t gfp_mask) { struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask); @@ -710,7 +710,7 @@ blk_alloc_request(struct request_queue *q, struct io_cq *icq, if (flags & REQ_ELVPRIV) { rq->elv.icq = icq; - if (unlikely(elv_set_request(q, rq, gfp_mask))) { + if (unlikely(elv_set_request(q, rq, bio, gfp_mask))) { mempool_free(rq, q->rq.rq_pool); return NULL; } @@ -809,6 +809,22 @@ static bool blk_rq_should_init_elevator(struct bio *bio) return true; } +/** + * 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 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; +} + /** * get_request - get a free request * @q: request_queue to allocate request from @@ -836,7 +852,7 @@ static struct request *get_request(struct request_queue *q, int rw_flags, int may_queue; retry: et = q->elevator->type; - ioc = current->io_context; + ioc = rq_ioc(bio); if (unlikely(blk_queue_dead(q))) return NULL; @@ -919,14 +935,16 @@ retry: /* create icq if missing */ if ((rw_flags & REQ_ELVPRIV) && unlikely(et->icq_cache && !icq)) { - ioc = create_io_context(gfp_mask, q->node); - if (ioc) - icq = ioc_create_icq(ioc, q, gfp_mask); + create_io_context(gfp_mask, q->node); + ioc = rq_ioc(bio); + if (!ioc) + goto fail_alloc; + icq = ioc_create_icq(ioc, q, gfp_mask); if (!icq) goto fail_alloc; } - rq = blk_alloc_request(q, icq, rw_flags, gfp_mask); + rq = blk_alloc_request(q, bio, icq, rw_flags, gfp_mask); if (unlikely(!rq)) goto fail_alloc; diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 9a4eac490e0b..abac87337d70 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3299,7 +3299,8 @@ split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq) * Allocate cfq data structures associated with this request. */ static int -cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) +cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio, + gfp_t gfp_mask) { struct cfq_data *cfqd = q->elevator->elevator_data; struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq); diff --git a/block/elevator.c b/block/elevator.c index 451654fadab0..be3ab6df0fea 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -663,12 +663,13 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq) return NULL; } -int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) +int elv_set_request(struct request_queue *q, struct request *rq, + struct bio *bio, gfp_t gfp_mask) { struct elevator_queue *e = q->elevator; if (e->type->ops.elevator_set_req_fn) - return e->type->ops.elevator_set_req_fn(q, rq, gfp_mask); + return e->type->ops.elevator_set_req_fn(q, rq, bio, gfp_mask); return 0; } diff --git a/fs/bio.c b/fs/bio.c index b980ecde026a..142214b80039 100644 --- a/fs/bio.c +++ b/fs/bio.c @@ -19,12 +19,14 @@ #include #include #include +#include #include #include #include #include #include #include +#include #include /* for struct sg_iovec */ #include @@ -418,6 +420,7 @@ void bio_put(struct bio *bio) * last put frees it */ if (atomic_dec_and_test(&bio->bi_cnt)) { + bio_disassociate_task(bio); bio->bi_next = NULL; bio->bi_destructor(bio); } @@ -1641,6 +1644,64 @@ bad: } EXPORT_SYMBOL(bioset_create); +#ifdef CONFIG_BLK_CGROUP +/** + * bio_associate_current - associate a bio with %current + * @bio: target bio + * + * Associate @bio with %current if it hasn't been associated yet. Block + * layer will treat @bio as if it were issued by %current no matter which + * task actually issues it. + * + * This function takes an extra reference of @task's io_context and blkcg + * which will be put when @bio is released. The caller must own @bio, + * ensure %current->io_context exists, and is responsible for synchronizing + * calls to this function. + */ +int bio_associate_current(struct bio *bio) +{ + struct io_context *ioc; + struct cgroup_subsys_state *css; + + if (bio->bi_ioc) + return -EBUSY; + + ioc = current->io_context; + if (!ioc) + return -ENOENT; + + /* acquire active ref on @ioc and associate */ + get_io_context_active(ioc); + bio->bi_ioc = ioc; + + /* associate blkcg if exists */ + rcu_read_lock(); + css = task_subsys_state(current, blkio_subsys_id); + if (css && css_tryget(css)) + bio->bi_css = css; + rcu_read_unlock(); + + return 0; +} + +/** + * bio_disassociate_task - undo bio_associate_current() + * @bio: target bio + */ +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; + } +} + +#endif /* CONFIG_BLK_CGROUP */ + static void __init biovec_init_slabs(void) { int i; diff --git a/include/linux/bio.h b/include/linux/bio.h index 129a9c097958..692d3d5b49f5 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -268,6 +268,14 @@ extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int); extern unsigned int bvec_nr_vecs(unsigned short idx); +#ifdef CONFIG_BLK_CGROUP +int bio_associate_current(struct bio *bio); +void bio_disassociate_task(struct bio *bio); +#else /* CONFIG_BLK_CGROUP */ +static inline int bio_associate_current(struct bio *bio) { return -ENOENT; } +static inline void bio_disassociate_task(struct bio *bio) { } +#endif /* CONFIG_BLK_CGROUP */ + /* * bio_set is used to allow other portions of the IO system to * allocate their own private memory pools for bio and iovec structures. diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 4053cbd4490e..0edb65dd8edd 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -14,6 +14,8 @@ struct bio; struct bio_integrity_payload; struct page; struct block_device; +struct io_context; +struct cgroup_subsys_state; typedef void (bio_end_io_t) (struct bio *, int); typedef void (bio_destructor_t) (struct bio *); @@ -66,6 +68,14 @@ struct bio { bio_end_io_t *bi_end_io; void *bi_private; +#ifdef CONFIG_BLK_CGROUP + /* + * Optional ioc and 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; +#endif #if defined(CONFIG_BLK_DEV_INTEGRITY) struct bio_integrity_payload *bi_integrity; /* data integrity */ #endif diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 97fb2557a18c..c03af7687bb4 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -28,7 +28,8 @@ typedef int (elevator_may_queue_fn) (struct request_queue *, int); typedef void (elevator_init_icq_fn) (struct io_cq *); typedef void (elevator_exit_icq_fn) (struct io_cq *); -typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, gfp_t); +typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, + struct bio *, gfp_t); typedef void (elevator_put_req_fn) (struct request *); typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *); typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *); @@ -129,7 +130,8 @@ extern void elv_unregister_queue(struct request_queue *q); extern int elv_may_queue(struct request_queue *, int); extern void elv_abort_queue(struct request_queue *); extern void elv_completed_request(struct request_queue *, struct request *); -extern int elv_set_request(struct request_queue *, struct request *, gfp_t); +extern int elv_set_request(struct request_queue *q, struct request *rq, + struct bio *bio, gfp_t gfp_mask); extern void elv_put_request(struct request_queue *, struct request *); extern void elv_drain_elevator(struct request_queue *);