Commit cfa27356 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Keith Busch
Browse files

nvme-pci: remove nvmeq->tags 



There is no real need to have a pointer to the tagset in
struct nvme_queue, as we only need it in a single place, and that place
can derive the used tagset from the device and qid trivially.  This
fixes a problem with stale pointer exposure when tagsets are reset,
and also shrinks the nvme_queue structure.  It also matches what most
other transports have done since day 1.

Reported-by: default avatarEdmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
parent b716e688

drivers/nvme/host/pci.c

+8 −15
Original line number Diff line number Diff line
@@ -167,7 +167,6 @@ struct nvme_queue { 
	 /* only used for poll queues: */

	spinlock_t cq_poll_lock ____cacheline_aligned_in_smp;

	volatile struct nvme_completion *cqes;

	struct blk_mq_tags **tags;

	dma_addr_t sq_dma_addr;

	dma_addr_t cq_dma_addr;

	u32 __iomem *q_db;
@@ -376,29 +375,17 @@ static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, 


	WARN_ON(hctx_idx != 0);

	WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);

	WARN_ON(nvmeq->tags);



	hctx->driver_data = nvmeq;

	nvmeq->tags = &dev->admin_tagset.tags[0];

	return 0;

}



static void nvme_admin_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)

{

	struct nvme_queue *nvmeq = hctx->driver_data;



	nvmeq->tags = NULL;

}



static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,

			  unsigned int hctx_idx)

{

	struct nvme_dev *dev = data;

	struct nvme_queue *nvmeq = &dev->queues[hctx_idx + 1];



	if (!nvmeq->tags)

		nvmeq->tags = &dev->tagset.tags[hctx_idx];



	WARN_ON(dev->tagset.tags[hctx_idx] != hctx->tags);

	hctx->driver_data = nvmeq;

	return 0;
@@ -948,6 +935,13 @@ static inline void nvme_ring_cq_doorbell(struct nvme_queue *nvmeq) 
		writel(head, nvmeq->q_db + nvmeq->dev->db_stride);

}



static inline struct blk_mq_tags *nvme_queue_tagset(struct nvme_queue *nvmeq)

{

	if (!nvmeq->qid)

		return nvmeq->dev->admin_tagset.tags[0];

	return nvmeq->dev->tagset.tags[nvmeq->qid - 1];

}



static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx)

{

	volatile struct nvme_completion *cqe = &nvmeq->cqes[idx];
@@ -972,7 +966,7 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx) 
		return;

	}



	req = blk_mq_tag_to_rq(*nvmeq->tags, cqe->command_id);

	req = blk_mq_tag_to_rq(nvme_queue_tagset(nvmeq), cqe->command_id);

	trace_nvme_sq(req, cqe->sq_head, nvmeq->sq_tail);

	nvme_end_request(req, cqe->status, cqe->result);

}
@@ -1572,7 +1566,6 @@ static const struct blk_mq_ops nvme_mq_admin_ops = { 
	.queue_rq	= nvme_queue_rq,

	.complete	= nvme_pci_complete_rq,

	.init_hctx	= nvme_admin_init_hctx,

	.exit_hctx      = nvme_admin_exit_hctx,

	.init_request	= nvme_init_request,

	.timeout	= nvme_timeout,

};

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