[PATCH RFC v2 10/12] nvmet: make discovery subsystem dynamic
Hannes Reinecke
hare at kernel.org
Fri Jun 19 01:36:50 PDT 2026
In preparation to make nvmet namespace-aware convert the
discovery subsystem to dynamic allocation.
Signed-off-by: Hannes Reinecke <hare at kernel.org>
---
drivers/nvme/target/configfs.c | 33 +++++++++++++---
drivers/nvme/target/core.c | 30 ++++++--------
drivers/nvme/target/discovery.c | 86 +++++++++++++++++++++++++++++------------
drivers/nvme/target/nvmet.h | 11 ++++--
4 files changed, 108 insertions(+), 52 deletions(-)
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index b88f897f06e25e3e604615c75dc55cc5b2a1f1a1..6030647cee937195d772bcf4b92cb37b6ebf9f08 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -51,6 +51,16 @@ static const struct nvmet_type_name_map nvmet_addr_family[] = {
{ NVMF_ADDR_FAMILY_LOOP, "loop" },
};
+u64 nvmet_get_ns_id(struct net *net_ns)
+{
+ struct ns_common *ns;
+
+ if (!net_ns)
+ return 0;
+ ns = to_ns_common(net_ns);
+ return net_ns == &init_net ? 0 : ns->ns_id;
+}
+
static bool nvmet_is_port_enabled(struct nvmet_port *p, const char *caller)
{
if (p->enabled)
@@ -1734,14 +1744,17 @@ static const struct config_item_type nvmet_subsys_type = {
static struct config_group *nvmet_subsys_make(struct config_group *group,
const char *name)
{
- struct nvmet_subsys *subsys;
+ struct nvmet_subsys *subsys, *disc_subsys;
if (sysfs_streq(name, NVME_DISC_SUBSYS_NAME)) {
pr_err("can't create discovery subsystem through configfs\n");
return ERR_PTR(-EINVAL);
}
- if (sysfs_streq(name, nvmet_disc_subsys->subsysnqn)) {
+ disc_subsys = nvmet_get_disc_subsys(&init_net);
+ if (!disc_subsys)
+ return ERR_PTR(-ENOENT);
+ if (sysfs_streq(name, disc_subsys->subsysnqn)) {
pr_err("can't create subsystem using unique discovery NQN\n");
return ERR_PTR(-EINVAL);
}
@@ -2308,12 +2321,17 @@ static struct config_group nvmet_hosts_group;
static ssize_t nvmet_root_discovery_nqn_show(struct config_item *item,
char *page)
{
- return snprintf(page, PAGE_SIZE, "%s\n", nvmet_disc_subsys->subsysnqn);
+ struct nvmet_subsys *disc_subsys = nvmet_get_disc_subsys(&init_net);
+
+ if (!disc_subsys)
+ return -ENOENT;
+ return snprintf(page, PAGE_SIZE, "%s\n", disc_subsys->subsysnqn);
}
static ssize_t nvmet_root_discovery_nqn_store(struct config_item *item,
const char *page, size_t count)
{
+ struct nvmet_subsys *disc_subsys;
struct list_head *entry;
char *old_nqn, *new_nqn;
size_t len;
@@ -2338,12 +2356,15 @@ static ssize_t nvmet_root_discovery_nqn_store(struct config_item *item,
return -EINVAL;
}
}
- old_nqn = nvmet_disc_subsys->subsysnqn;
- nvmet_disc_subsys->subsysnqn = new_nqn;
+ disc_subsys = nvmet_get_disc_subsys(&init_net);
+ if (disc_subsys) {
+ old_nqn = disc_subsys->subsysnqn;
+ disc_subsys->subsysnqn = new_nqn;
+ }
up_write(&nvmet_config_sem);
kfree(old_nqn);
- return len;
+ return disc_subsys ? len : -ENOENT;
}
CONFIGFS_ATTR(nvmet_root_, discovery_nqn);
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 62dd59b9aa4f1c9bfd32361e3f06ab1520424ce8..1831a218319b84a1e1a1cfba7fb48e3ad40b09f7 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -1798,22 +1798,27 @@ static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,
const char *subsysnqn)
{
struct nvmet_subsys_link *p;
+ struct nvmet_subsys *disc_subsys;
if (!port)
return NULL;
+ disc_subsys = nvmet_get_disc_subsys(&init_net);
+ if (!disc_subsys)
+ return NULL;
+
if (!strcmp(NVME_DISC_SUBSYS_NAME, subsysnqn)) {
- if (!kref_get_unless_zero(&nvmet_disc_subsys->ref))
+ if (!kref_get_unless_zero(&disc_subsys->ref))
return NULL;
- return nvmet_disc_subsys;
+ return disc_subsys;
}
down_read(&nvmet_config_sem);
- if (!strncmp(nvmet_disc_subsys->subsysnqn, subsysnqn,
+ if (!strncmp(disc_subsys->subsysnqn, subsysnqn,
NVMF_NQN_SIZE)) {
- if (kref_get_unless_zero(&nvmet_disc_subsys->ref)) {
+ if (kref_get_unless_zero(&disc_subsys->ref)) {
up_read(&nvmet_config_sem);
- return nvmet_disc_subsys;
+ return disc_subsys;
}
}
list_for_each_entry(p, &port->subsystems, entry) {
@@ -1888,14 +1893,8 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
INIT_LIST_HEAD(&subsys->ctrls);
INIT_LIST_HEAD(&subsys->hosts);
- ret = nvmet_debugfs_subsys_setup(subsys);
- if (ret)
- goto free_subsysnqn;
-
return subsys;
-free_subsysnqn:
- kfree(subsys->subsysnqn);
free_fr:
kfree(subsys->firmware_rev);
free_mn:
@@ -1976,18 +1975,12 @@ static int __init nvmet_init(void)
if (error)
goto out_free_nvmet_aen_work_queue;
- error = nvmet_init_discovery();
- if (error)
- goto out_exit_debugfs;
-
error = nvmet_init_configfs();
if (error)
- goto out_exit_discovery;
+ goto out_exit_debugfs;
return 0;
-out_exit_discovery:
- nvmet_exit_discovery();
out_exit_debugfs:
nvmet_exit_debugfs();
out_free_nvmet_aen_work_queue:
@@ -2006,7 +1999,6 @@ static int __init nvmet_init(void)
static void __exit nvmet_exit(void)
{
nvmet_exit_configfs();
- nvmet_exit_discovery();
nvmet_exit_debugfs();
ida_destroy(&cntlid_ida);
destroy_workqueue(nvmet_aen_wq);
diff --git a/drivers/nvme/target/discovery.c b/drivers/nvme/target/discovery.c
index 114869d16a1f3ce8740a2126a2cb491ec8007ed7..4a0e5929125ece4c98bf25918ce82b66d4140228 100644
--- a/drivers/nvme/target/discovery.c
+++ b/drivers/nvme/target/discovery.c
@@ -8,9 +8,44 @@
#include <generated/utsrelease.h>
#include "nvmet.h"
-struct nvmet_subsys *nvmet_disc_subsys;
+static DEFINE_XARRAY(nvmet_disc_xa);
-static u64 nvmet_genctr;
+struct nvmet_subsys *nvmet_get_disc_subsys(struct net *net_ns)
+{
+ struct nvmet_subsys *subsys;
+ u64 ns_id = nvmet_get_ns_id(net_ns);
+
+ subsys = xa_load(&nvmet_disc_xa, ns_id);
+ return subsys;
+}
+
+int nvmet_add_disc_subsys(struct net *net_ns)
+{
+ struct nvmet_subsys *disc_subsys;
+ u64 ns_id = nvmet_get_ns_id(net_ns);
+ int err;
+
+ disc_subsys = nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME,
+ NVME_NQN_CURR);
+ if (IS_ERR(disc_subsys))
+ return PTR_ERR(disc_subsys);
+ err = xa_insert(&nvmet_disc_xa, ns_id,
+ disc_subsys, GFP_KERNEL);
+ if (err < 0)
+ nvmet_subsys_put(disc_subsys);
+
+ return err;
+}
+
+void nvmet_del_disc_subsys(struct net *net_ns)
+{
+ struct nvmet_subsys *disc_subsys;
+ u64 ns_id = nvmet_get_ns_id(net_ns);
+
+ disc_subsys = xa_erase(&nvmet_disc_xa, ns_id);
+ if (disc_subsys)
+ nvmet_subsys_put(disc_subsys);
+}
static void __nvmet_disc_changed(struct nvmet_port *port,
struct nvmet_ctrl *ctrl)
@@ -29,18 +64,22 @@ void nvmet_port_disc_changed(struct nvmet_port *port,
struct nvmet_subsys *subsys)
{
struct nvmet_ctrl *ctrl;
+ struct nvmet_subsys *disc_subsys;
lockdep_assert_held(&nvmet_config_sem);
- nvmet_genctr++;
+ disc_subsys = nvmet_get_disc_subsys(&init_net);
+ if (WARN_ON(!disc_subsys))
+ return;
+ disc_subsys->genctr++;
- mutex_lock(&nvmet_disc_subsys->lock);
- list_for_each_entry(ctrl, &nvmet_disc_subsys->ctrls, subsys_entry) {
+ mutex_lock(&disc_subsys->lock);
+ list_for_each_entry(ctrl, &disc_subsys->ctrls, subsys_entry) {
if (subsys && !nvmet_host_allowed(subsys, ctrl->hostnqn))
continue;
__nvmet_disc_changed(port, ctrl);
}
- mutex_unlock(&nvmet_disc_subsys->lock);
+ mutex_unlock(&disc_subsys->lock);
/* If transport can signal change, notify transport */
if (port->tr_ops && port->tr_ops->discovery_chg)
@@ -52,15 +91,19 @@ static void __nvmet_subsys_disc_changed(struct nvmet_port *port,
struct nvmet_host *host)
{
struct nvmet_ctrl *ctrl;
+ struct nvmet_subsys *disc_subsys;
- mutex_lock(&nvmet_disc_subsys->lock);
- list_for_each_entry(ctrl, &nvmet_disc_subsys->ctrls, subsys_entry) {
+ disc_subsys = nvmet_get_disc_subsys(&init_net);
+ if (WARN_ON(!disc_subsys))
+ return;
+ mutex_lock(&disc_subsys->lock);
+ list_for_each_entry(ctrl, &disc_subsys->ctrls, subsys_entry) {
if (host && strcmp(nvmet_host_name(host), ctrl->hostnqn))
continue;
__nvmet_disc_changed(port, ctrl);
}
- mutex_unlock(&nvmet_disc_subsys->lock);
+ mutex_unlock(&disc_subsys->lock);
}
void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
@@ -68,9 +111,13 @@ void nvmet_subsys_disc_changed(struct nvmet_subsys *subsys,
{
struct nvmet_port *port;
struct nvmet_subsys_link *s;
+ struct nvmet_subsys *disc_subsys;
lockdep_assert_held(&nvmet_config_sem);
- nvmet_genctr++;
+ disc_subsys = nvmet_get_disc_subsys(&init_net);
+ if (WARN_ON(!disc_subsys))
+ return;
+ disc_subsys->genctr++;
list_for_each_entry(port, nvmet_ports, global_entry)
list_for_each_entry(s, &port->subsystems, entry) {
@@ -173,6 +220,7 @@ static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)
u16 status = 0;
void *buffer;
char traddr[NVMF_TRADDR_SIZE];
+ struct nvmet_subsys *disc_subsys;
if (!nvmet_check_transfer_len(req, data_len))
return;
@@ -207,10 +255,12 @@ static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)
}
hdr = buffer;
+ disc_subsys = nvmet_get_disc_subsys(&init_net);
+
nvmet_set_disc_traddr(req, req->port, traddr);
nvmet_format_discovery_entry(hdr, req->port,
- nvmet_disc_subsys->subsysnqn,
+ disc_subsys->subsysnqn,
traddr, NVME_NQN_CURR, numrec);
numrec++;
@@ -235,7 +285,7 @@ static void nvmet_execute_disc_get_log_page(struct nvmet_req *req)
numrec++;
}
- hdr->genctr = cpu_to_le64(nvmet_genctr);
+ hdr->genctr = cpu_to_le64(disc_subsys->genctr);
hdr->numrec = cpu_to_le64(numrec);
hdr->recfmt = cpu_to_le16(0);
@@ -428,15 +478,3 @@ u16 nvmet_parse_discovery_cmd(struct nvmet_req *req)
}
}
-
-int __init nvmet_init_discovery(void)
-{
- nvmet_disc_subsys =
- nvmet_subsys_alloc(NVME_DISC_SUBSYS_NAME, NVME_NQN_CURR);
- return PTR_ERR_OR_ZERO(nvmet_disc_subsys);
-}
-
-void nvmet_exit_discovery(void)
-{
- nvmet_subsys_put(nvmet_disc_subsys);
-}
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 3305a88684ecab5d59c53d7f975d1b0a1cb213a2..2bbee443ce7c7a13be15976c18ab003265a366cb 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -325,6 +325,9 @@ struct nvmet_subsys {
u16 cntlid_min;
u16 cntlid_max;
+ /* For discovery subsystems */
+ u64 genctr;
+
struct list_head ctrls;
struct list_head hosts;
@@ -696,11 +699,13 @@ void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
int __init nvmet_init_configfs(void);
void __exit nvmet_exit_configfs(void);
+extern struct list_head *nvmet_get_port_list(struct net *net_ns);
-int __init nvmet_init_discovery(void);
-void nvmet_exit_discovery(void);
+extern u64 nvmet_get_ns_id(struct net *net_ns);
+extern int nvmet_add_disc_subsys(struct net *net_ns);
+extern void nvmet_del_disc_subsys(struct net *net_ns);
+extern struct nvmet_subsys *nvmet_get_disc_subsys(struct net *net_ns);
-extern struct nvmet_subsys *nvmet_disc_subsys;
extern struct rw_semaphore nvmet_config_sem;
extern u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];
--
2.51.0
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