[PATCH 5.10 163/199] nvme-pci: fix error unwind in nvme_map_data

Greg Kroah-Hartman
2021-01-25T19:29:46Z

From: Christoph Hellwig <hch@lst.de>

commit fa0732168fa1369dd089e5b06d6158a68229f7b7 upstream.

Properly unwind step by step using refactored helpers from nvme_unmap_data
to avoid a potential double dma_unmap on a mapping failure.

Fixes: 7fe07d14f71f ("nvme-pci: merge nvme_free_iod into nvme_unmap_data")
Reported-by: Marc Orr <marcorr@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Marc Orr <marcorr@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/nvme/host/pci.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)

--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -682,7 +682,7 @@ static blk_status_t nvme_pci_setup_prps(
__le64 *old_prp_list = prp_list;
prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);
if (!prp_list)
- return BLK_STS_RESOURCE;
+ goto free_prps;
list[iod->npages++] = prp_list;
prp_list[0] = old_prp_list[i - 1];
old_prp_list[i - 1] = cpu_to_le64(prp_dma);
@@ -702,14 +702,14 @@ static blk_status_t nvme_pci_setup_prps(
dma_addr = sg_dma_address(sg);
dma_len = sg_dma_len(sg);
}
-
done:
cmnd->dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sg));
cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma);
-
return BLK_STS_OK;
-
- bad_sgl:
+free_prps:
+ nvme_free_prps(dev, req);
+ return BLK_STS_RESOURCE;
+bad_sgl:
WARN(DO_ONCE(nvme_print_sgl, iod->sg, iod->nents),
"Invalid SGL for payload:%d nents:%d\n",
blk_rq_payload_bytes(req), iod->nents);
@@ -781,7 +781,7 @@ static blk_status_t nvme_pci_setup_sgls(

sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma);
if (!sg_list)
- return BLK_STS_RESOURCE;
+ goto free_sgls;

i = 0;
nvme_pci_iod_list(req)[iod->npages++] = sg_list;
@@ -794,6 +794,9 @@ static blk_status_t nvme_pci_setup_sgls(
} while (--entries > 0);

return BLK_STS_OK;
+free_sgls:
+ nvme_free_sgls(dev, req);
+ return BLK_STS_RESOURCE;
}

static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev,
@@ -862,7 +865,7 @@ static blk_status_t nvme_map_data(struct
sg_init_table(iod->sg, blk_rq_nr_phys_segments(req));
iod->nents = blk_rq_map_sg(req->q, req, iod->sg);
if (!iod->nents)
- goto out;
+ goto out_free_sg;

if (is_pci_p2pdma_page(sg_page(iod->sg)))
nr_mapped = pci_p2pdma_map_sg_attrs(dev->dev, iod->sg,
@@ -871,16 +874,21 @@ static blk_status_t nvme_map_data(struct
nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents,
rq_dma_dir(req), DMA_ATTR_NO_WARN);
if (!nr_mapped)
- goto out;
+ goto out_free_sg;

iod->use_sgl = nvme_pci_use_sgls(dev, req);
if (iod->use_sgl)
ret = nvme_pci_setup_sgls(dev, req, &cmnd->rw, nr_mapped);
else
ret = nvme_pci_setup_prps(dev, req, &cmnd->rw);
-out:
if (ret != BLK_STS_OK)
- nvme_unmap_data(dev, req);
+ goto out_unmap_sg;
+ return BLK_STS_OK;
+
+out_unmap_sg:
+ nvme_unmap_sg(dev, req);
+out_free_sg:
+ mempool_free(iod->sg, dev->iod_mempool);
return ret;
}