On Thu, Nov 02, 2023 at 06:06:33PM +0100, Mikulas Patocka wrote:

Then, try this patch (without "iommu=panic"), reproduce the deadlock and tell us which one of the "printk" statements is triggered during the deadlock.

The "821" one - see below.

Mikulas

---

drivers/nvme/host/core.c | 8 ++++++-- drivers/nvme/host/pci.c | 27 ++++++++++++++++++++++----- 2 files changed, 28 insertions(+), 7 deletions(-)

Index: linux-stable/drivers/nvme/host/pci.c

--- linux-stable.orig/drivers/nvme/host/pci.c 2023-10-31 15:35:38.000000000 +0100 +++ linux-stable/drivers/nvme/host/pci.c 2023-11-02 17:38:20.000000000 +0100 @@ -622,6 +622,10 @@ static blk_status_t nvme_pci_setup_prps( prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma); if (!prp_list) { iod->nr_allocations = -1;

• if (nprps <= (256 / 8))
  

• 	printk("allocation failure at %d\n", __LINE__);
  

• else
  

• 	printk("allocation failure at %d\n", __LINE__);
  

  return BLK_STS_RESOURCE; } iod->list[0].prp_list = prp_list;

@@ -631,8 +635,10 @@ static blk_status_t nvme_pci_setup_prps( if (i == NVME_CTRL_PAGE_SIZE >> 3) { __le64 *old_prp_list = prp_list; prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);

• 	if (!prp_list)
  

• 	if (!prp_list) {
  

• 		printk("allocation failure at %d\n", __LINE__);
  	goto free_prps;
  

• 	}
  iod->list[iod->nr_allocations++].prp_list = prp_list;
  prp_list[0] = old_prp_list[i - 1];
  old_prp_list[i - 1] = cpu_to_le64(prp_dma);
  

@@ -712,6 +718,7 @@ static blk_status_t nvme_pci_setup_sgls( sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma); if (!sg_list) { iod->nr_allocations = -1;

• printk("allocation failure at %d\n", __LINE__);
  

  return BLK_STS_RESOURCE; }

@@ -736,8 +743,10 @@ static blk_status_t nvme_setup_prp_simpl unsigned int first_prp_len = NVME_CTRL_PAGE_SIZE - offset; iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);

• if (dma_mapping_error(dev->dev, iod->first_dma))

• if (dma_mapping_error(dev->dev, iod->first_dma)) {

• printk("allocation failure at %d\n", __LINE__);
  

  return BLK_STS_RESOURCE;
• } iod->dma_len = bv->bv_len;

cmnd->dptr.prp1 = cpu_to_le64(iod->first_dma); @@ -755,8 +764,10 @@ static blk_status_t nvme_setup_sgl_simpl struct nvme_iod *iod = blk_mq_rq_to_pdu(req); iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);

• if (dma_mapping_error(dev->dev, iod->first_dma))

• if (dma_mapping_error(dev->dev, iod->first_dma)) {

• printk("allocation failure at %d\n", __LINE__);
  

  return BLK_STS_RESOURCE;
• } iod->dma_len = bv->bv_len;

cmnd->flags = NVME_CMD_SGL_METABUF; @@ -791,8 +802,10 @@ static blk_status_t nvme_map_data(struct iod->dma_len = 0; iod->sgt.sgl = mempool_alloc(dev->iod_mempool, GFP_ATOMIC);

• if (!iod->sgt.sgl)

• if (!iod->sgt.sgl) {

• printk("allocation failure at %d\n", __LINE__);
  

  return BLK_STS_RESOURCE;
• } sg_init_table(iod->sgt.sgl, blk_rq_nr_phys_segments(req)); iod->sgt.orig_nents = blk_rq_map_sg(req->q, req, iod->sgt.sgl); if (!iod->sgt.orig_nents)

@@ -801,8 +814,12 @@ static blk_status_t nvme_map_data(struct rc = dma_map_sgtable(dev->dev, &iod->sgt, rq_dma_dir(req), DMA_ATTR_NO_WARN); if (rc) {

• if (rc == -EREMOTEIO)
  

• if (rc == -EREMOTEIO) {
  

• 	printk("allocation failure at %d\n", __LINE__);
  ret = BLK_STS_TARGET;
  

• } else {
  

• 	printk("allocation failure at %d\n", __LINE__);
  

I get a lot of this one.

• }
  

  goto out_free_sg; }

Index: linux-stable/drivers/nvme/host/core.c =================================================================== --- linux-stable.orig/drivers/nvme/host/core.c 2023-10-31 15:35:38.000000000 +0100 +++ linux-stable/drivers/nvme/host/core.c 2023-11-02 17:12:39.000000000 +0100 @@ -708,8 +708,10 @@ blk_status_t nvme_fail_nonready_command( ctrl->state != NVME_CTRL_DELETING && ctrl->state != NVME_CTRL_DEAD && !test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ctrl->flags) &&

•    !blk_noretry_request(rq) && !(rq->cmd_flags & REQ_NVME_MPATH))
  

•    !blk_noretry_request(rq) && !(rq->cmd_flags & REQ_NVME_MPATH)) {
  

• printk("allocation failure at %d\n", __LINE__);
  

  return BLK_STS_RESOURCE;
• } return nvme_host_path_error(rq);

} EXPORT_SYMBOL_GPL(nvme_fail_nonready_command); @@ -784,8 +786,10 @@ static blk_status_t nvme_setup_discard(s * discard page. If that's also busy, it's safe to return * busy, as we know we can make progress once that's freed. */

• if (test_and_set_bit_lock(0, &ns->ctrl->discard_page_busy))
  

• if (test_and_set_bit_lock(0, &ns->ctrl->discard_page_busy)) {
  

• 	printk("allocation failure at %d\n", __LINE__);
  return BLK_STS_RESOURCE;
  

• }
  

range = page_address(ns->ctrl->discard_page); }