[PATCH 4/8] nvmet: add Verify command support for bdev-ns

[Chaitanya Kulkarni <chaitanyak@nvidia.com>]

From: Chaitanya Kulkarni <kch@nvidia.com>

Add support for handling verify command on target. Call into
__blkdev_issue_verify, which the block layer expands into the
REQ_OP_VERIFY LBAs.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
---
 drivers/nvme/target/admin-cmd.c   |  3 ++-
 drivers/nvme/target/io-cmd-bdev.c | 39 +++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 613a4d8feac1..87cad64895e6 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -408,7 +408,8 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 	id->nn = cpu_to_le32(ctrl->subsys->max_nsid);
 	id->mnan = cpu_to_le32(NVMET_MAX_NAMESPACES);
 	id->oncs = cpu_to_le16(NVME_CTRL_ONCS_DSM |
-			NVME_CTRL_ONCS_WRITE_ZEROES);
+			NVME_CTRL_ONCS_WRITE_ZEROES |
+			NVME_CTRL_ONCS_VERIFY);
 
 	/* XXX: don't report vwc if the underlying device is write through */
 	id->vwc = NVME_CTRL_VWC_PRESENT;
diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
index ec45e597084b..5a888cdadfea 100644
--- a/drivers/nvme/target/io-cmd-bdev.c
+++ b/drivers/nvme/target/io-cmd-bdev.c
@@ -128,6 +128,7 @@ static u16 blk_to_nvme_status(struct nvmet_req *req, blk_status_t blk_sts)
 		switch (req->cmd->common.opcode) {
 		case nvme_cmd_dsm:
 		case nvme_cmd_write_zeroes:
+		case nvme_cmd_verify:
 			status = NVME_SC_ONCS_NOT_SUPPORTED | NVME_SC_DNR;
 			break;
 		default:
@@ -153,6 +154,10 @@ static u16 blk_to_nvme_status(struct nvmet_req *req, blk_status_t blk_sts)
 		req->error_slba =
 			le64_to_cpu(req->cmd->write_zeroes.slba);
 		break;
+	case nvme_cmd_verify:
+		req->error_slba =
+			le64_to_cpu(req->cmd->verify.slba);
+		break;
 	default:
 		req->error_slba = 0;
 	}
@@ -428,6 +433,37 @@ static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
 	}
 }
 
+static void nvmet_bdev_execute_verify(struct nvmet_req *req)
+{
+	struct nvme_verify_cmd *verify = &req->cmd->verify;
+	struct bio *bio = NULL;
+	sector_t nr_sector;
+	sector_t sector;
+	int ret;
+
+	if (!nvmet_check_transfer_len(req, 0))
+		return;
+
+	if (!bdev_verify_sectors(req->ns->bdev)) {
+		nvmet_req_complete(req, NVME_SC_INTERNAL | NVME_SC_DNR);
+		return;
+	}
+
+	sector = le64_to_cpu(verify->slba) << (req->ns->blksize_shift - 9);
+	nr_sector = (((sector_t)le16_to_cpu(verify->length) + 1) <<
+			(req->ns->blksize_shift - 9));
+
+	ret = __blkdev_issue_verify(req->ns->bdev, sector, nr_sector,
+			GFP_KERNEL, &bio);
+	if (bio) {
+		bio->bi_private = req;
+		bio->bi_end_io = nvmet_bio_done;
+		submit_bio(bio);
+	} else {
+		nvmet_req_complete(req, errno_to_nvme_status(req, ret));
+	}
+}
+
 u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
 {
 	struct nvme_command *cmd = req->cmd;
@@ -448,6 +484,9 @@ u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
 	case nvme_cmd_write_zeroes:
 		req->execute = nvmet_bdev_execute_write_zeroes;
 		return 0;
+	case nvme_cmd_verify:
+		req->execute = nvmet_bdev_execute_verify;
+		return 0;
 	default:
 		pr_err("unhandled cmd %d on qid %d\n", cmd->common.opcode,
 		       req->sq->qid);
-- 
2.22.1