diff options
Diffstat (limited to 'block/blk-core.c')
-rw-r--r-- | block/blk-core.c | 190 |
1 files changed, 161 insertions, 29 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 2eb722d48773..5131993b23a1 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -554,29 +554,30 @@ void blk_cleanup_queue(struct request_queue *q) * Drain all requests queued before DYING marking. Set DEAD flag to * prevent that q->request_fn() gets invoked after draining finished. */ - if (q->mq_ops) { - blk_mq_freeze_queue(q); - spin_lock_irq(lock); - } else { - spin_lock_irq(lock); + blk_freeze_queue(q); + spin_lock_irq(lock); + if (!q->mq_ops) __blk_drain_queue(q, true); - } queue_flag_set(QUEUE_FLAG_DEAD, q); spin_unlock_irq(lock); + /* for synchronous bio-based driver finish in-flight integrity i/o */ + blk_flush_integrity(); + /* @q won't process any more request, flush async actions */ del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer); blk_sync_queue(q); if (q->mq_ops) blk_mq_free_queue(q); + percpu_ref_exit(&q->q_usage_counter); spin_lock_irq(lock); if (q->queue_lock != &q->__queue_lock) q->queue_lock = &q->__queue_lock; spin_unlock_irq(lock); - bdi_destroy(&q->backing_dev_info); + bdi_unregister(&q->backing_dev_info); /* @q is and will stay empty, shutdown and put */ blk_put_queue(q); @@ -629,6 +630,40 @@ struct request_queue *blk_alloc_queue(gfp_t gfp_mask) } EXPORT_SYMBOL(blk_alloc_queue); +int blk_queue_enter(struct request_queue *q, gfp_t gfp) +{ + while (true) { + int ret; + + if (percpu_ref_tryget_live(&q->q_usage_counter)) + return 0; + + if (!gfpflags_allow_blocking(gfp)) + return -EBUSY; + + ret = wait_event_interruptible(q->mq_freeze_wq, + !atomic_read(&q->mq_freeze_depth) || + blk_queue_dying(q)); + if (blk_queue_dying(q)) + return -ENODEV; + if (ret) + return ret; + } +} + +void blk_queue_exit(struct request_queue *q) +{ + percpu_ref_put(&q->q_usage_counter); +} + +static void blk_queue_usage_counter_release(struct percpu_ref *ref) +{ + struct request_queue *q = + container_of(ref, struct request_queue, q_usage_counter); + + wake_up_all(&q->mq_freeze_wq); +} + struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) { struct request_queue *q; @@ -690,11 +725,22 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) init_waitqueue_head(&q->mq_freeze_wq); - if (blkcg_init_queue(q)) + /* + * Init percpu_ref in atomic mode so that it's faster to shutdown. + * See blk_register_queue() for details. + */ + if (percpu_ref_init(&q->q_usage_counter, + blk_queue_usage_counter_release, + PERCPU_REF_INIT_ATOMIC, GFP_KERNEL)) goto fail_bdi; + if (blkcg_init_queue(q)) + goto fail_ref; + return q; +fail_ref: + percpu_ref_exit(&q->q_usage_counter); fail_bdi: bdi_destroy(&q->backing_dev_info); fail_split: @@ -763,7 +809,7 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id) } EXPORT_SYMBOL(blk_init_queue_node); -static void blk_queue_bio(struct request_queue *q, struct bio *bio); +static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio); struct request_queue * blk_init_allocated_queue(struct request_queue *q, request_fn_proc *rfn, @@ -1160,8 +1206,8 @@ rq_starved: * @bio: bio to allocate request for (can be %NULL) * @gfp_mask: allocation mask * - * Get a free request from @q. If %__GFP_WAIT is set in @gfp_mask, this - * function keeps retrying under memory pressure and fails iff @q is dead. + * Get a free request from @q. If %__GFP_DIRECT_RECLAIM is set in @gfp_mask, + * this function keeps retrying under memory pressure and fails iff @q is dead. * * Must be called with @q->queue_lock held and, * Returns ERR_PTR on failure, with @q->queue_lock held. @@ -1181,7 +1227,7 @@ retry: if (!IS_ERR(rq)) return rq; - if (!(gfp_mask & __GFP_WAIT) || unlikely(blk_queue_dying(q))) { + if (!gfpflags_allow_blocking(gfp_mask) || unlikely(blk_queue_dying(q))) { blk_put_rl(rl); return rq; } @@ -1259,11 +1305,11 @@ EXPORT_SYMBOL(blk_get_request); * BUG. * * WARNING: When allocating/cloning a bio-chain, careful consideration should be - * given to how you allocate bios. In particular, you cannot use __GFP_WAIT for - * anything but the first bio in the chain. Otherwise you risk waiting for IO - * completion of a bio that hasn't been submitted yet, thus resulting in a - * deadlock. Alternatively bios should be allocated using bio_kmalloc() instead - * of bio_alloc(), as that avoids the mempool deadlock. + * given to how you allocate bios. In particular, you cannot use + * __GFP_DIRECT_RECLAIM for anything but the first bio in the chain. Otherwise + * you risk waiting for IO completion of a bio that hasn't been submitted yet, + * thus resulting in a deadlock. Alternatively bios should be allocated using + * bio_kmalloc() instead of bio_alloc(), as that avoids the mempool deadlock. * If possible a big IO should be split into smaller parts when allocation * fails. Partial allocation should not be an error, or you risk a live-lock. */ @@ -1529,6 +1575,9 @@ bool bio_attempt_front_merge(struct request_queue *q, struct request *req, * @q: request_queue new bio is being queued at * @bio: new bio being queued * @request_count: out parameter for number of traversed plugged requests + * @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, @@ -1594,6 +1643,30 @@ out: return ret; } +unsigned int blk_plug_queued_count(struct request_queue *q) +{ + struct blk_plug *plug; + struct request *rq; + struct list_head *plug_list; + unsigned int ret = 0; + + plug = current->plug; + if (!plug) + goto out; + + if (q->mq_ops) + plug_list = &plug->mq_list; + else + plug_list = &plug->list; + + list_for_each_entry(rq, plug_list, queuelist) { + if (rq->q == q) + ret++; + } +out: + return ret; +} + void init_request_from_bio(struct request *req, struct bio *bio) { req->cmd_type = REQ_TYPE_FS; @@ -1608,7 +1681,7 @@ void init_request_from_bio(struct request *req, struct bio *bio) blk_rq_bio_prep(req->q, req, bio); } -static void blk_queue_bio(struct request_queue *q, struct bio *bio) +static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio) { const bool sync = !!(bio->bi_rw & REQ_SYNC); struct blk_plug *plug; @@ -1628,7 +1701,7 @@ static void blk_queue_bio(struct request_queue *q, struct bio *bio) if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { bio->bi_error = -EIO; bio_endio(bio); - return; + return BLK_QC_T_NONE; } if (bio->bi_rw & (REQ_FLUSH | REQ_FUA)) { @@ -1641,9 +1714,11 @@ static void blk_queue_bio(struct request_queue *q, struct bio *bio) * Check if we can merge with the plugged list before grabbing * any locks. */ - if (!blk_queue_nomerges(q) && - blk_attempt_plug_merge(q, bio, &request_count, NULL)) - return; + if (!blk_queue_nomerges(q)) { + if (blk_attempt_plug_merge(q, bio, &request_count, NULL)) + return BLK_QC_T_NONE; + } else + request_count = blk_plug_queued_count(q); spin_lock_irq(q->queue_lock); @@ -1719,6 +1794,8 @@ get_rq: out_unlock: spin_unlock_irq(q->queue_lock); } + + return BLK_QC_T_NONE; } /* @@ -1924,12 +2001,13 @@ end_io: * a lower device by calling into generic_make_request recursively, which * means the bio should NOT be touched after the call to ->make_request_fn. */ -void generic_make_request(struct bio *bio) +blk_qc_t generic_make_request(struct bio *bio) { struct bio_list bio_list_on_stack; + blk_qc_t ret = BLK_QC_T_NONE; if (!generic_make_request_checks(bio)) - return; + goto out; /* * We only want one ->make_request_fn to be active at a time, else @@ -1943,7 +2021,7 @@ void generic_make_request(struct bio *bio) */ if (current->bio_list) { bio_list_add(current->bio_list, bio); - return; + goto out; } /* following loop may be a bit non-obvious, and so deserves some @@ -1966,11 +2044,24 @@ void generic_make_request(struct bio *bio) do { struct request_queue *q = bdev_get_queue(bio->bi_bdev); - q->make_request_fn(q, bio); + if (likely(blk_queue_enter(q, __GFP_DIRECT_RECLAIM) == 0)) { + + ret = q->make_request_fn(q, bio); + + blk_queue_exit(q); - bio = bio_list_pop(current->bio_list); + bio = bio_list_pop(current->bio_list); + } else { + struct bio *bio_next = bio_list_pop(current->bio_list); + + bio_io_error(bio); + bio = bio_next; + } } while (bio); current->bio_list = NULL; /* deactivate */ + +out: + return ret; } EXPORT_SYMBOL(generic_make_request); @@ -1984,7 +2075,7 @@ EXPORT_SYMBOL(generic_make_request); * interfaces; @bio must be presetup and ready for I/O. * */ -void submit_bio(int rw, struct bio *bio) +blk_qc_t submit_bio(int rw, struct bio *bio) { bio->bi_rw |= rw; @@ -2018,7 +2109,7 @@ void submit_bio(int rw, struct bio *bio) } } - generic_make_request(bio); + return generic_make_request(bio); } EXPORT_SYMBOL(submit_bio); @@ -3224,6 +3315,47 @@ void blk_finish_plug(struct blk_plug *plug) } EXPORT_SYMBOL(blk_finish_plug); +bool blk_poll(struct request_queue *q, blk_qc_t cookie) +{ + struct blk_plug *plug; + long state; + + if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) || + !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) + return false; + + plug = current->plug; + if (plug) + blk_flush_plug_list(plug, false); + + state = current->state; + while (!need_resched()) { + unsigned int queue_num = blk_qc_t_to_queue_num(cookie); + struct blk_mq_hw_ctx *hctx = q->queue_hw_ctx[queue_num]; + int ret; + + hctx->poll_invoked++; + + ret = q->mq_ops->poll(hctx, blk_qc_t_to_tag(cookie)); + if (ret > 0) { + hctx->poll_success++; + set_current_state(TASK_RUNNING); + return true; + } + + if (signal_pending_state(state, current)) + set_current_state(TASK_RUNNING); + + if (current->state == TASK_RUNNING) + return true; + if (ret < 0) + break; + cpu_relax(); + } + + return false; +} + #ifdef CONFIG_PM /** * blk_pm_runtime_init - Block layer runtime PM initialization routine |