From 19c66e59ce57e7b181625cbb408d48eb10837763 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 3 Dec 2014 19:38:04 +0800 Subject: [PATCH] blk-mq: prevent unmapped hw queue from being scheduled When one hardware queue has no mapped software queues, it shouldn't have been scheduled. Otherwise WARNING or OOPS can triggered. blk_mq_hw_queue_mapped() helper is introduce for fixing the problem. Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- block/blk-mq.c | 8 ++++++-- block/blk-mq.h | 5 +++++ 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 4854e709aa34..b21a3b6f7b65 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -589,7 +589,7 @@ static void blk_mq_rq_timer(unsigned long priv) * If not software queues are currently mapped to this * hardware queue, there's nothing to check */ - if (!hctx->nr_ctx || !hctx->tags) + if (!blk_mq_hw_queue_mapped(hctx)) continue; blk_mq_tag_busy_iter(hctx, blk_mq_check_expired, &data); @@ -809,7 +809,8 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) { - if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state))) + if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state) || + !blk_mq_hw_queue_mapped(hctx))) return; if (!async) { @@ -916,6 +917,9 @@ static void blk_mq_delay_work_fn(struct work_struct *work) void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) { + if (unlikely(!blk_mq_hw_queue_mapped(hctx))) + return; + kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->delay_work, msecs_to_jiffies(msecs)); } diff --git a/block/blk-mq.h b/block/blk-mq.h index d567d5283ffa..206230e64f79 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -115,4 +115,9 @@ static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data, data->hctx = hctx; } +static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx) +{ + return hctx->nr_ctx && hctx->tags; +} + #endif