diff options
Diffstat (limited to 'block/blk-core.c')
| -rw-r--r-- | block/blk-core.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index e93df6d386a0..fa36b4ff7d63 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -3312,6 +3312,47 @@ 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 |