Re: Intermittent storage (dm-crypt?) freeze - regression 6.4->6.5

["Marek Marczykowski-Górecki" <marmarek@invisiblethingslab.com>]

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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);
>  	}


-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

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