nvmet: add metadata support for block devices

Allocate the metadata SGL buffers and set metadata fields for the
request. Then create a block IO request for the metadata from the
protection SG list.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/core.c

@@ -900,8 +900,11 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 	req->sq = sq;
 	req->ops = ops;
 	req->sg = NULL;
+	req->metadata_sg = NULL;
 	req->sg_cnt = 0;
+	req->metadata_sg_cnt = 0;
 	req->transfer_len = 0;
+	req->metadata_len = 0;
 	req->cqe->status = 0;
 	req->cqe->sq_head = 0;
 	req->ns = NULL;
@@ -986,50 +989,90 @@ bool nvmet_check_data_len_lte(struct nvmet_req *req, size_t data_len)
 	return true;
 }
 
-int nvmet_req_alloc_sgl(struct nvmet_req *req)
+static unsigned int nvmet_data_transfer_len(struct nvmet_req *req)
 {
-	struct pci_dev *p2p_dev = NULL;
+	return req->transfer_len - req->metadata_len;
+}
 
-	if (IS_ENABLED(CONFIG_PCI_P2PDMA)) {
-		if (req->sq->ctrl && req->ns)
-			p2p_dev = radix_tree_lookup(&req->sq->ctrl->p2p_ns_map,
-						    req->ns->nsid);
+static int nvmet_req_alloc_p2pmem_sgls(struct nvmet_req *req)
+{
+	req->sg = pci_p2pmem_alloc_sgl(req->p2p_dev, &req->sg_cnt,
+			nvmet_data_transfer_len(req));
+	if (!req->sg)
+		goto out_err;
 
-		req->p2p_dev = NULL;
-		if (req->sq->qid && p2p_dev) {
-			req->sg = pci_p2pmem_alloc_sgl(p2p_dev, &req->sg_cnt,
-						       req->transfer_len);
-			if (req->sg) {
-				req->p2p_dev = p2p_dev;
-				return 0;
-			}
-		}
+	if (req->metadata_len) {
+		req->metadata_sg = pci_p2pmem_alloc_sgl(req->p2p_dev,
+				&req->metadata_sg_cnt, req->metadata_len);
+		if (!req->metadata_sg)
+			goto out_free_sg;
+	}
+	return 0;
+out_free_sg:
+	pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
+out_err:
+	return -ENOMEM;
+}
 
-		/*
-		 * If no P2P memory was available we fallback to using
-		 * regular memory
-		 */
+static bool 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->sg = sgl_alloc(req->transfer_len, GFP_KERNEL, &req->sg_cnt);
+	req->p2p_dev = NULL;
+	return false;
+}
+
+int nvmet_req_alloc_sgls(struct nvmet_req *req)
+{
+	if (nvmet_req_find_p2p_dev(req) && !nvmet_req_alloc_p2pmem_sgls(req))
+		return 0;
+
+	req->sg = sgl_alloc(nvmet_data_transfer_len(req), GFP_KERNEL,
+			    &req->sg_cnt);
 	if (unlikely(!req->sg))
-		return -ENOMEM;
+		goto out;
+
+	if (req->metadata_len) {
+		req->metadata_sg = sgl_alloc(req->metadata_len, GFP_KERNEL,
+					     &req->metadata_sg_cnt);
+		if (unlikely(!req->metadata_sg))
+			goto out_free;
+	}
 
 	return 0;
+out_free:
+	sgl_free(req->sg);
+out:
+	return -ENOMEM;
 }
-EXPORT_SYMBOL_GPL(nvmet_req_alloc_sgl);
+EXPORT_SYMBOL_GPL(nvmet_req_alloc_sgls);
 
-void nvmet_req_free_sgl(struct nvmet_req *req)
+void nvmet_req_free_sgls(struct nvmet_req *req)
 {
-	if (req->p2p_dev)
+	if (req->p2p_dev) {
 		pci_p2pmem_free_sgl(req->p2p_dev, req->sg);
-	else
+		if (req->metadata_sg)
+			pci_p2pmem_free_sgl(req->p2p_dev, req->metadata_sg);
+	} else {
 		sgl_free(req->sg);
+		if (req->metadata_sg)
+			sgl_free(req->metadata_sg);
+	}
 
 	req->sg = NULL;
+	req->metadata_sg = NULL;
 	req->sg_cnt = 0;
+	req->metadata_sg_cnt = 0;
 }
-EXPORT_SYMBOL_GPL(nvmet_req_free_sgl);
+EXPORT_SYMBOL_GPL(nvmet_req_free_sgls);
 
 static inline bool nvmet_cc_en(u32 cc)
 {

drivers/nvme/target/io-cmd-bdev.c

@@ -169,6 +169,61 @@ static void nvmet_bio_done(struct bio *bio)
 		bio_put(bio);
 }
 
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+static int nvmet_bdev_alloc_bip(struct nvmet_req *req, struct bio *bio,
+				struct sg_mapping_iter *miter)
+{
+	struct blk_integrity *bi;
+	struct bio_integrity_payload *bip;
+	struct block_device *bdev = req->ns->bdev;
+	int rc;
+	size_t resid, len;
+
+	bi = bdev_get_integrity(bdev);
+	if (unlikely(!bi)) {
+		pr_err("Unable to locate bio_integrity\n");
+		return -ENODEV;
+	}
+
+	bip = bio_integrity_alloc(bio, GFP_NOIO,
+		min_t(unsigned int, req->metadata_sg_cnt, BIO_MAX_PAGES));
+	if (IS_ERR(bip)) {
+		pr_err("Unable to allocate bio_integrity_payload\n");
+		return PTR_ERR(bip);
+	}
+
+	bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
+	/* virtual start sector must be in integrity interval units */
+	bip_set_seed(bip, bio->bi_iter.bi_sector >>
+		     (bi->interval_exp - SECTOR_SHIFT));
+
+	resid = bip->bip_iter.bi_size;
+	while (resid > 0 && sg_miter_next(miter)) {
+		len = min_t(size_t, miter->length, resid);
+		rc = bio_integrity_add_page(bio, miter->page, len,
+					    offset_in_page(miter->addr));
+		if (unlikely(rc != len)) {
+			pr_err("bio_integrity_add_page() failed; %d\n", rc);
+			sg_miter_stop(miter);
+			return -ENOMEM;
+		}
+
+		resid -= len;
+		if (len < miter->length)
+			miter->consumed -= miter->length - len;
+	}
+	sg_miter_stop(miter);
+
+	return 0;
+}
+#else
+static int nvmet_bdev_alloc_bip(struct nvmet_req *req, struct bio *bio,
+				struct sg_mapping_iter *miter)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
 static void nvmet_bdev_execute_rw(struct nvmet_req *req)
 {
 	int sg_cnt = req->sg_cnt;
@@ -176,9 +231,12 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req)
 	struct scatterlist *sg;
 	struct blk_plug plug;
 	sector_t sector;
-	int op, i;
+	int op, i, rc;
+	struct sg_mapping_iter prot_miter;
+	unsigned int iter_flags;
+	unsigned int total_len = nvmet_rw_data_len(req) + req->metadata_len;
 
-	if (!nvmet_check_transfer_len(req, nvmet_rw_data_len(req)))
+	if (!nvmet_check_transfer_len(req, total_len))
 		return;
 
 	if (!req->sg_cnt) {
@@ -190,8 +248,10 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req)
 		op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
 		if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
 			op |= REQ_FUA;
+		iter_flags = SG_MITER_TO_SG;
 	} else {
 		op = REQ_OP_READ;
+		iter_flags = SG_MITER_FROM_SG;
 	}
 
 	if (is_pci_p2pdma_page(sg_page(req->sg)))
@@ -213,11 +273,24 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req)
 	bio->bi_opf = op;
 
 	blk_start_plug(&plug);
+	if (req->metadata_len)
+		sg_miter_start(&prot_miter, req->metadata_sg,
+			       req->metadata_sg_cnt, iter_flags);
+
 	for_each_sg(req->sg, sg, req->sg_cnt, i) {
 		while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 				!= sg->length) {
 			struct bio *prev = bio;
 
+			if (req->metadata_len) {
+				rc = nvmet_bdev_alloc_bip(req, bio,
+							  &prot_miter);
+				if (unlikely(rc)) {
+					bio_io_error(bio);
+					return;
+				}
+			}
+
 			bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
 			bio_set_dev(bio, req->ns->bdev);
 			bio->bi_iter.bi_sector = sector;
@@ -231,6 +304,14 @@ static void nvmet_bdev_execute_rw(struct nvmet_req *req)
 		sg_cnt--;
 	}
 
+	if (req->metadata_len) {
+		rc = nvmet_bdev_alloc_bip(req, bio, &prot_miter);
+		if (unlikely(rc)) {
+			bio_io_error(bio);
+			return;
+		}
+	}
+
 	submit_bio(bio);
 	blk_finish_plug(&plug);
 }
@@ -358,6 +439,8 @@ u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
 	case nvme_cmd_read:
 	case nvme_cmd_write:
 		req->execute = nvmet_bdev_execute_rw;
+		if (req->sq->ctrl->pi_support && nvmet_ns_has_pi(req->ns))
+			req->metadata_len = nvmet_rw_metadata_len(req);
 		return 0;
 	case nvme_cmd_flush:
 		req->execute = nvmet_bdev_execute_flush;

drivers/nvme/target/nvmet.h

@@ -309,6 +309,7 @@ struct nvmet_req {
 	struct nvmet_cq		*cq;
 	struct nvmet_ns		*ns;
 	struct scatterlist	*sg;
+	struct scatterlist	*metadata_sg;
 	struct bio_vec		inline_bvec[NVMET_MAX_INLINE_BIOVEC];
 	union {
 		struct {
@@ -322,8 +323,10 @@ struct nvmet_req {
 		} f;
 	};
 	int			sg_cnt;
+	int			metadata_sg_cnt;
 	/* data length as parsed from the SGL descriptor: */
 	size_t			transfer_len;
+	size_t			metadata_len;
 
 	struct nvmet_port	*port;
 
@@ -394,8 +397,8 @@ void nvmet_req_uninit(struct nvmet_req *req);
 bool nvmet_check_transfer_len(struct nvmet_req *req, size_t len);
 bool nvmet_check_data_len_lte(struct nvmet_req *req, size_t data_len);
 void nvmet_req_complete(struct nvmet_req *req, u16 status);
-int nvmet_req_alloc_sgl(struct nvmet_req *req);
-void nvmet_req_free_sgl(struct nvmet_req *req);
+int nvmet_req_alloc_sgls(struct nvmet_req *req);
+void nvmet_req_free_sgls(struct nvmet_req *req);
 
 void nvmet_execute_keep_alive(struct nvmet_req *req);
 

drivers/nvme/target/rdma.c

@@ -546,7 +546,7 @@ static void nvmet_rdma_release_rsp(struct nvmet_rdma_rsp *rsp)
 	}
 
 	if (rsp->req.sg != rsp->cmd->inline_sg)
-		nvmet_req_free_sgl(&rsp->req);
+		nvmet_req_free_sgls(&rsp->req);
 
 	if (unlikely(!list_empty_careful(&queue->rsp_wr_wait_list)))
 		nvmet_rdma_process_wr_wait_list(queue);
@@ -708,7 +708,7 @@ static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp,
 	if (!rsp->req.transfer_len)
 		return 0;
 
-	ret = nvmet_req_alloc_sgl(&rsp->req);
+	ret = nvmet_req_alloc_sgls(&rsp->req);
 	if (unlikely(ret < 0))
 		goto error_out;