From: Max Gurtovoy mgurtovoy@nvidia.com
[ Upstream commit bcd9a0797d73eeff659582f23277e7ab6e5f18f3 ]
In case p2p device was found but the p2p pool is empty, the nvme target is still trying to free the sgl from the p2p pool instead of the regular sgl pool and causing a crash (BUG() is called). Instead, assign the p2p_dev for the request only if it was allocated from p2p pool.
This is the crash that was caused:
[Sun May 30 19:13:53 2021] ------------[ cut here ]------------ [Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518! [Sun May 30 19:13:53 2021] invalid opcode: 0000 [#1] SMP PTI ... [Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518! ... [Sun May 30 19:13:53 2021] RIP: 0010:gen_pool_free_owner+0xa8/0xb0 ... [Sun May 30 19:13:53 2021] Call Trace: [Sun May 30 19:13:53 2021] ------------[ cut here ]------------ [Sun May 30 19:13:53 2021] pci_free_p2pmem+0x2b/0x70 [Sun May 30 19:13:53 2021] pci_p2pmem_free_sgl+0x4f/0x80 [Sun May 30 19:13:53 2021] nvmet_req_free_sgls+0x1e/0x80 [nvmet] [Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518! [Sun May 30 19:13:53 2021] nvmet_rdma_release_rsp+0x4e/0x1f0 [nvmet_rdma] [Sun May 30 19:13:53 2021] nvmet_rdma_send_done+0x1c/0x60 [nvmet_rdma]
Fixes: c6e3f1339812 ("nvmet: add metadata support for block devices") Reviewed-by: Israel Rukshin israelr@nvidia.com Signed-off-by: Max Gurtovoy mgurtovoy@nvidia.com Reviewed-by: Logan Gunthorpe logang@deltatee.com Reviewed-by: Chaitanya Kulkarni chaitanya.kulkarni@wdc.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/target/core.c | 33 ++++++++++++++++----------------- 1 file changed, 16 insertions(+), 17 deletions(-)
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index 348057fdc568..7d16cb4cd8ac 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -999,19 +999,23 @@ static unsigned int nvmet_data_transfer_len(struct nvmet_req *req) return req->transfer_len - req->metadata_len; }
-static int nvmet_req_alloc_p2pmem_sgls(struct nvmet_req *req) +static int nvmet_req_alloc_p2pmem_sgls(struct pci_dev *p2p_dev, + struct nvmet_req *req) { - req->sg = pci_p2pmem_alloc_sgl(req->p2p_dev, &req->sg_cnt, + req->sg = pci_p2pmem_alloc_sgl(p2p_dev, &req->sg_cnt, nvmet_data_transfer_len(req)); if (!req->sg) goto out_err;
if (req->metadata_len) { - req->metadata_sg = pci_p2pmem_alloc_sgl(req->p2p_dev, + req->metadata_sg = pci_p2pmem_alloc_sgl(p2p_dev, &req->metadata_sg_cnt, req->metadata_len); if (!req->metadata_sg) goto out_free_sg; } + + req->p2p_dev = p2p_dev; + return 0; out_free_sg: pci_p2pmem_free_sgl(req->p2p_dev, req->sg); @@ -1019,25 +1023,19 @@ out_err: return -ENOMEM; }
-static bool nvmet_req_find_p2p_dev(struct nvmet_req *req) +static struct pci_dev *nvmet_req_find_p2p_dev(struct nvmet_req *req) { - if (!IS_ENABLED(CONFIG_PCI_P2PDMA)) - return false; - - if (req->sq->ctrl && req->sq->qid && req->ns) { - req->p2p_dev = radix_tree_lookup(&req->sq->ctrl->p2p_ns_map, - req->ns->nsid); - if (req->p2p_dev) - return true; - } - - req->p2p_dev = NULL; - return false; + if (!IS_ENABLED(CONFIG_PCI_P2PDMA) || + !req->sq->ctrl || !req->sq->qid || !req->ns) + return NULL; + return radix_tree_lookup(&req->sq->ctrl->p2p_ns_map, req->ns->nsid); }
int nvmet_req_alloc_sgls(struct nvmet_req *req) { - if (nvmet_req_find_p2p_dev(req) && !nvmet_req_alloc_p2pmem_sgls(req)) + struct pci_dev *p2p_dev = nvmet_req_find_p2p_dev(req); + + if (p2p_dev && !nvmet_req_alloc_p2pmem_sgls(p2p_dev, req)) return 0;
req->sg = sgl_alloc(nvmet_data_transfer_len(req), GFP_KERNEL, @@ -1066,6 +1064,7 @@ void nvmet_req_free_sgls(struct nvmet_req *req) pci_p2pmem_free_sgl(req->p2p_dev, req->sg); if (req->metadata_sg) pci_p2pmem_free_sgl(req->p2p_dev, req->metadata_sg); + req->p2p_dev = NULL; } else { sgl_free(req->sg); if (req->metadata_sg)