[PATCH RFC v3] nvmet: basic RMEDIA support for target

[Wang Yugui <wangyugui@e16-tech.com>]

Rotational media(RMEDIA) support is added to the NVMe 2.0 specification.
We add Rotational media(RMEDIA) basic support to nvme target.

Signed-off-by: Wang Yugui <wangyugui@e16-tech.com>
---
changelog of PATCH RFC v3
- restore the process nvmet_req_find_ns() dropped in v2
changelog of PATCH RFC v2
- change 'bdev_nonrot(ns->bdev)' to '!bdev_nonrot(ns->bdev)' based on comment.
- add some support for 'nvme cmdset-ind-id-ns'

 drivers/nvme/target/admin-cmd.c   | 42 +++++++++++++++++++++++++++++++
 drivers/nvme/target/core.c        |  2 ++
 drivers/nvme/target/io-cmd-bdev.c |  1 +
 drivers/nvme/target/nvmet.h       |  1 +
 4 files changed, 55 insertions(+)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index f7e1156ac7ec..20a28102f8a0 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -489,6 +489,54 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 	nvmet_req_complete(req, status);
 }
 
+static void nvmet_execute_identify_indep(struct nvmet_req *req)
+{
+	struct nvme_id_ns_cs_indep  *id;
+	u16 status;
+
+	id = kzalloc(sizeof(*id), GFP_KERNEL);
+	if (!id) {
+		status = NVME_SC_INTERNAL;
+		goto out;
+	}
+
+	/*
+	 * Our namespace might always be shared.  Not just with other
+	 * controllers, but also with any other user of the block device.
+	 */
+	id->nmic |= NVME_NS_NMIC_SHARED;
+
+	id->nstat |= NVME_NSTAT_NRDY;
+
+	/* return an all zeroed buffer if we can't find an active namespace */
+	status = nvmet_req_find_ns(req);
+	if (status) {
+		status = 0;
+		goto done;
+	}
+
+	if (nvmet_ns_revalidate(req->ns)) {
+		mutex_lock(&req->ns->subsys->lock);
+		nvmet_ns_changed(req->ns->subsys, req->ns->nsid);
+		mutex_unlock(&req->ns->subsys->lock);
+	}
+
+	id->anagrpid = cpu_to_le32(req->ns->anagrpid);
+
+	if (req->ns->readonly)
+		id->nsattr |= NVME_NS_ATTR_RO;
+
+	if (req->ns->rotational)
+		id->nsfeat |= NVME_INDEP_NS_FEAT_RMEDIA;
+
+done:
+	if (!status)
+		status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
+	kfree(id);
+out:
+	nvmet_req_complete(req, status);
+}
+
 static void nvmet_execute_identify_ns(struct nvmet_req *req)
 {
 	struct nvme_id_ns *id;
@@ -706,6 +745,9 @@ static void nvmet_execute_identify(struct nvmet_req *req)
 			break;
 		}
 		break;
+	case NVME_ID_CNS_NS_CS_INDEP:
+		nvmet_execute_identify_indep(req);
+		return;
 	case NVME_ID_CNS_CS_CTRL:
 		switch (req->cmd->identify.csi) {
 		case NVME_CSI_NVM:
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index ed2424f8a396..2790fedb593b 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -1254,6 +1254,8 @@ static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
 	else
 		ctrl->cap |= ctrl->port->max_queue_size - 1;
 
+	ctrl->cap |= NVME_CAP_CRMS_CRIMS;
+
 	if (nvmet_is_passthru_subsys(ctrl->subsys))
 		nvmet_passthrough_override_cap(ctrl);
 }
diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
index 0bda83d0fc3e..d15ad1a864bc 100644
--- a/drivers/nvme/target/io-cmd-bdev.c
+++ b/drivers/nvme/target/io-cmd-bdev.c
@@ -104,6 +104,7 @@ int nvmet_bdev_ns_enable(struct nvmet_ns *ns)
 
 	ns->pi_type = 0;
 	ns->metadata_size = 0;
+	ns->rotational = !bdev_nonrot(ns->bdev);
 	if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY))
 		nvmet_bdev_ns_enable_integrity(ns);
 
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 190f55e6d753..86eeeadf3787 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -62,6 +62,7 @@ struct nvmet_ns {
 	struct block_device	*bdev;
 	struct file		*file;
 	bool			readonly;
+	bool			rotational;
 	u32			nsid;
 	u32			blksize_shift;
 	loff_t			size;
-- 
2.36.2