nvmet: add ZBD over ZNS backend support

NVMe TP 4053 – Zoned Namespaces (ZNS) allows host software to
communicate with a non-volatile memory subsystem using zones for NVMe
protocol-based controllers. NVMeOF already support the ZNS NVMe
Protocol compliant devices on the target in the passthru mode. There
are generic zoned block devices like  Shingled Magnetic Recording (SMR)
HDDs that are not based on the NVMe protocol.

This patch adds ZNS backend support for non-ZNS zoned block devices as
NVMeOF targets.

This support includes implementing the new command set NVME_CSI_ZNS,
adding different command handlers for ZNS command set such as NVMe
Identify Controller, NVMe Identify Namespace, NVMe Zone Append,
NVMe Zone Management Send and NVMe Zone Management Receive.

With the new command set identifier, we also update the target command
effects logs to reflect the ZNS compliant commands.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 77873d56cff5..dd16704c9b6b 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -16,6 +16,7 @@
 #include "nvmet.h"
 
 struct workqueue_struct *buffered_io_wq;
+struct workqueue_struct *zbd_wq;
 static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];
 static DEFINE_IDA(cntlid_ida);
 
@@ -883,6 +884,10 @@ static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 		if (req->ns->file)
 			return nvmet_file_parse_io_cmd(req);
 		return nvmet_bdev_parse_io_cmd(req);
+	case NVME_CSI_ZNS:
+		if (IS_ENABLED(CONFIG_BLK_DEV_ZONED))
+			return nvmet_bdev_zns_parse_io_cmd(req);
+		return NVME_SC_INVALID_IO_CMD_SET;
 	default:
 		return NVME_SC_INVALID_IO_CMD_SET;
 	}
@@ -1592,11 +1597,15 @@ static int __init nvmet_init(void)
 
 	nvmet_ana_group_enabled[NVMET_DEFAULT_ANA_GRPID] = 1;
 
+	zbd_wq = alloc_workqueue("nvmet-zbd-wq", WQ_MEM_RECLAIM, 0);
+	if (!zbd_wq)
+		return -ENOMEM;
+
 	buffered_io_wq = alloc_workqueue("nvmet-buffered-io-wq",
 			WQ_MEM_RECLAIM, 0);
 	if (!buffered_io_wq) {
 		error = -ENOMEM;
-		goto out;
+		goto out_free_zbd_work_queue;
 	}
 
 	error = nvmet_init_discovery();
@@ -1612,7 +1621,8 @@ out_exit_discovery:
 	nvmet_exit_discovery();
 out_free_work_queue:
 	destroy_workqueue(buffered_io_wq);
-out:
+out_free_zbd_work_queue:
+	destroy_workqueue(zbd_wq);
 	return error;
 }
 
@@ -1622,6 +1632,7 @@ static void __exit nvmet_exit(void)
 	nvmet_exit_discovery();
 	ida_destroy(&cntlid_ida);
 	destroy_workqueue(buffered_io_wq);
+	destroy_workqueue(zbd_wq);
 
 	BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_entry) != 1024);
 	BUILD_BUG_ON(sizeof(struct nvmf_disc_rsp_page_hdr) != 1024);