[PATCH 1/4] nvmet: make the subsystem type configurable

Hannes Reinecke
2022-04-20T09:28:07Z

Make the subsystem type configurable to allow for unique
discovery subsystems by changing the subsystem type to
'discovery'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/nvme/target/configfs.c | 60 +++++++++++++++++++++++++++++++++
drivers/nvme/target/discovery.c | 2 +-
drivers/nvme/target/nvmet.h | 1 +
3 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index e44b2988759e..38b0ab9fb721 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -834,6 +834,7 @@ static int nvmet_port_subsys_allow_link(struct config_item *parent,
}

list_add_tail(&link->entry, &port->subsystems);
+ subsys->port_count++;
nvmet_port_disc_changed(port, subsys);

up_write(&nvmet_config_sem);
@@ -862,6 +863,7 @@ static void nvmet_port_subsys_drop_link(struct config_item *parent,

found:
list_del(&p->entry);
+ subsys->port_count--;
nvmet_port_del_ctrls(port, subsys);
nvmet_port_disc_changed(port, subsys);

@@ -1234,6 +1236,63 @@ static ssize_t nvmet_subsys_attr_model_store(struct config_item *item,
}
CONFIGFS_ATTR(nvmet_subsys_, attr_model);

+static const struct nvmet_type_name_map nvmet_subsys_type_map[] = {
+ { NVME_NQN_DISC, "referral" },
+ { NVME_NQN_NVME, "nvme" },
+ { NVME_NQN_CURR, "discovery" },
+};
+
+static ssize_t nvmet_subsys_attr_type_show(struct config_item *item,
+ char *page)
+{
+ u8 type = to_subsys(item)->type;
+ int i;
+
+ for (i = 1; i < ARRAY_SIZE(nvmet_subsys_type_map); i++) {
+ if (nvmet_subsys_type_map[i].type == type)
+ return snprintf(page, PAGE_SIZE, "%s\n",
+ nvmet_subsys_type_map[i].name);
+ }
+
+ return snprintf(page, PAGE_SIZE, "\n");
+}
+
+static ssize_t nvmet_subsys_attr_type_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct nvmet_subsys *subsys = to_subsys(item);
+ int i;
+
+ if (subsys->subsys_discovered)
+ return -EACCES;
+
+ for (i = 0; i < ARRAY_SIZE(nvmet_subsys_type_map); i++) {
+ if (sysfs_streq(page, nvmet_subsys_type_map[i].name))
+ goto found;
+ }
+
+ pr_err("Invalid value '%s' for subsystem type\n", page);
+ return -EINVAL;
+
+found:
+ down_write(&nvmet_config_sem);
+ if (subsys->port_count) {
+ pr_err("cannot change type when linked to ports\n");
+ up_write(&nvmet_config_sem);
+ return -EACCES;
+ }
+ if (!xa_empty(&subsys->namespaces)) {
+ pr_err("cannot change type when namespaces are configured\n");
+ up_write(&nvmet_config_sem);
+ return -EACCES;
+ }
+ subsys->type = nvmet_subsys_type_map[i].type;
+ up_write(&nvmet_config_sem);
+
+ return count;
+}
+CONFIGFS_ATTR(nvmet_subsys_, attr_type);
+
#ifdef CONFIG_BLK_DEV_INTEGRITY
static ssize_t nvmet_subsys_attr_pi_enable_show(struct config_item *item,
char *page)
@@ -1263,6 +1322,7 @@ static struct configfs_attribute *nvmet_subsys_attrs[] = {
&nvmet_subsys_attr_attr_cntlid_min,
&nvmet_subsys_attr_attr_cntlid_max,
&nvmet_subsys_attr_attr_model,
+ &nvmet_subsys_attr_attr_type,
#ifdef CONFIG_BLK_DEV_INTEGRITY
&nvmet_subsys_attr_attr_pi_enable,
#endif
diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
index c2162eef8ce1..b5012df790d5 100644
--- a/drivers/nvme/target/discovery.c
+++ b/drivers/nvme/target/discovery.c
@@ -219,7 +219,7 @@ static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)

nvmet_format_discovery_entry(hdr, req->port,
p->subsys->subsysnqn, traddr,
- NVME_NQN_NVME, numrec);
+ p->subsys->type, numrec);
numrec++;
}

diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 69818752a33a..ecba3890ce65 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -216,6 +216,7 @@ struct nvmet_subsys {

struct mutex lock;
struct kref ref;
+ unsigned int port_count;

struct xarray namespaces;
unsigned int nr_namespaces;
--
2.29.2