Merge "BACKPORT: blk-mq: grab rq->refcount before calling ->fn in blk_mq_tagset_busy_iter" (f610453d) · Commits · e / devices / android_kernel_oneplus_sm7250

block/blk-mq-tag.c

+25 −7

Original line number	Diff line number	Diff line
		@@ -218,6 +218,16 @@ struct bt_iter_data {
		bool reserved;
		};

		static struct request blk_mq_find_and_get_req(struct blk_mq_tags tags,
		unsigned int bitnr)
		{
		struct request *rq = tags->rqs[bitnr];

		if (!rq \|\| !refcount_inc_not_zero(&rq->ref))
		return NULL;
		return rq;
		}

		static bool bt_iter(struct sbitmap bitmap, unsigned int bitnr, void data)
		{
		struct bt_iter_data *iter_data = data;
		@@ -225,18 +235,23 @@ static bool bt_iter(struct sbitmap bitmap, unsigned int bitnr, void data)
		struct blk_mq_tags *tags = hctx->tags;
		bool reserved = iter_data->reserved;
		struct request *rq;
		bool ret = true;

		if (!reserved)
		bitnr += tags->nr_reserved_tags;
		rq = tags->rqs[bitnr];

		/*
		* We can hit rq == NULL here, because the tagging functions
		* test and set the bit before assining ->rqs[].
		*/
		if (rq && rq->q == hctx->queue)
		iter_data->fn(hctx, rq, iter_data->data, reserved);
		rq = blk_mq_find_and_get_req(tags, bitnr);
		if (!rq)
		return true;

		if (rq->q == hctx->queue)
		iter_data->fn(hctx, rq, iter_data->data, reserved);
		blk_mq_put_rq_ref(rq);
		return ret;
		}

		static void bt_for_each(struct blk_mq_hw_ctx hctx, struct sbitmap_queue bt,
		@@ -265,6 +280,7 @@ static bool bt_tags_iter(struct sbitmap bitmap, unsigned int bitnr, void data)
		struct blk_mq_tags *tags = iter_data->tags;
		bool reserved = iter_data->reserved;
		struct request *rq;
		bool ret = true;

		if (!reserved)
		bitnr += tags->nr_reserved_tags;
		@@ -273,11 +289,13 @@ static bool bt_tags_iter(struct sbitmap bitmap, unsigned int bitnr, void data)
		* We can hit rq == NULL here, because the tagging functions
		* test and set the bit before assining ->rqs[].
		*/
		rq = tags->rqs[bitnr];
		if (rq && blk_mq_request_started(rq))
		iter_data->fn(rq, iter_data->data, reserved);

		rq = blk_mq_find_and_get_req(tags, bitnr);
		if (!rq)
		return true;
		if (blk_mq_request_started(rq))
		iter_data->fn(rq, iter_data->data, reserved);
		blk_mq_put_rq_ref(rq);
		return ret;
		}

		static void bt_tags_for_each(struct blk_mq_tags tags, struct sbitmap_queue bt,

block/blk-mq.c

+13 −4

Original line number	Diff line number	Diff line
		@@ -812,6 +812,17 @@ static bool blk_mq_req_expired(struct request rq, unsigned long next)
		return false;
		}

		void blk_mq_put_rq_ref(struct request *rq)
		{
		struct blk_mq_hw_ctx *hctx;

		hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
		if (is_flush_rq(rq, hctx))
		rq->end_io(rq, 0);
		else if (refcount_dec_and_test(&rq->ref))
		__blk_mq_free_request(rq);
		}

		static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
		struct request rq, void priv, bool reserved)
		{
		@@ -844,11 +855,9 @@ static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
		*/
		if (blk_mq_req_expired(rq, next))
		blk_mq_rq_timed_out(rq, reserved);
		blk_mq_put_rq_ref(rq);
		return;

		if (is_flush_rq(rq, hctx))
		rq->end_io(rq, 0);
		else if (refcount_dec_and_test(&rq->ref))
		__blk_mq_free_request(rq);
		}

		static void blk_mq_timeout_work(struct work_struct *work)

block/blk-mq.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -39,6 +39,7 @@ void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx hctx, struct list_head list);
		bool blk_mq_get_driver_tag(struct request *rq);
		struct request blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx hctx,
		struct blk_mq_ctx *start);
		void blk_mq_put_rq_ref(struct request *rq);

		/*
		* Internal helpers for allocating/freeing the request map