[PATCH 1/8] nvmet: add debugfs support
Hannes Reinecke
hare at kernel.org
Fri Mar 22 00:03:26 PDT 2024
Add a debugfs hierarchy to display the configured subsystems
and the controllers attached to the subsystems.
Suggested-by: Redouane BOUFENGHOUR <redouane.boufenghour at shadow.tech>
Signed-off-by: Hannes Reinecke <hare at kernel.org>
---
drivers/nvme/target/Kconfig | 9 ++
drivers/nvme/target/Makefile | 1 +
drivers/nvme/target/core.c | 22 +++-
drivers/nvme/target/debugfs.c | 182 ++++++++++++++++++++++++++++++++++
drivers/nvme/target/debugfs.h | 42 ++++++++
drivers/nvme/target/nvmet.h | 8 +-
6 files changed, 261 insertions(+), 3 deletions(-)
create mode 100644 drivers/nvme/target/debugfs.c
create mode 100644 drivers/nvme/target/debugfs.h
diff --git a/drivers/nvme/target/Kconfig b/drivers/nvme/target/Kconfig
index 872dd1a0acd8..5740893ace6d 100644
--- a/drivers/nvme/target/Kconfig
+++ b/drivers/nvme/target/Kconfig
@@ -18,6 +18,15 @@ config NVME_TARGET
To configure the NVMe target you probably want to use the nvmetcli
tool from http://git.infradead.org/users/hch/nvmetcli.git.
+config NVME_TARGET_DEBUGFS
+ bool "NVMe Target debugfs support"
+ depends on NVME_TARGET
+ help
+ This enables debugfs support to display the connected controllers
+ to each subsystem
+
+ If unsure, say N.
+
config NVME_TARGET_PASSTHRU
bool "NVMe Target Passthrough support"
depends on NVME_TARGET
diff --git a/drivers/nvme/target/Makefile b/drivers/nvme/target/Makefile
index c66820102493..c402c44350b2 100644
--- a/drivers/nvme/target/Makefile
+++ b/drivers/nvme/target/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_NVME_TARGET_TCP) += nvmet-tcp.o
nvmet-y += core.o configfs.o admin-cmd.o fabrics-cmd.o \
discovery.o io-cmd-file.o io-cmd-bdev.o
+nvmet-$(CONFIG_NVME_TARGET_DEBUGFS) += debugfs.o
nvmet-$(CONFIG_NVME_TARGET_PASSTHRU) += passthru.o
nvmet-$(CONFIG_BLK_DEV_ZONED) += zns.o
nvmet-$(CONFIG_NVME_TARGET_AUTH) += fabrics-cmd-auth.o auth.o
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 1d1a7026e817..6cd1b92fc500 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -16,6 +16,7 @@
#include "trace.h"
#include "nvmet.h"
+#include "debugfs.h"
struct kmem_cache *nvmet_bvec_cache;
struct workqueue_struct *buffered_io_wq;
@@ -1463,6 +1464,7 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
mutex_lock(&subsys->lock);
list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
nvmet_setup_p2p_ns_map(ctrl, req);
+ nvmet_debugfs_ctrl_setup(ctrl);
mutex_unlock(&subsys->lock);
*ctrlp = ctrl;
@@ -1497,6 +1499,8 @@ static void nvmet_ctrl_free(struct kref *ref)
nvmet_destroy_auth(ctrl);
+ nvmet_debugfs_ctrl_free(ctrl);
+
ida_free(&cntlid_ida, ctrl->cntlid);
nvmet_async_events_free(ctrl);
@@ -1610,8 +1614,14 @@ 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:
@@ -1628,6 +1638,8 @@ static void nvmet_subsys_free(struct kref *ref)
WARN_ON_ONCE(!xa_empty(&subsys->namespaces));
+ nvmet_debugfs_subsys_free(subsys);
+
xa_destroy(&subsys->namespaces);
nvmet_passthru_subsys_free(subsys);
@@ -1681,11 +1693,18 @@ static int __init nvmet_init(void)
if (error)
goto out_free_nvmet_work_queue;
- error = nvmet_init_configfs();
+ error = nvmet_init_debugfs();
if (error)
goto out_exit_discovery;
+
+ error = nvmet_init_configfs();
+ if (error)
+ goto out_exit_debugfs;
+
return 0;
+out_exit_debugfs:
+ nvmet_exit_debugfs();
out_exit_discovery:
nvmet_exit_discovery();
out_free_nvmet_work_queue:
@@ -1702,6 +1721,7 @@ static int __init nvmet_init(void)
static void __exit nvmet_exit(void)
{
nvmet_exit_configfs();
+ nvmet_exit_debugfs();
nvmet_exit_discovery();
ida_destroy(&cntlid_ida);
destroy_workqueue(nvmet_wq);
diff --git a/drivers/nvme/target/debugfs.c b/drivers/nvme/target/debugfs.c
new file mode 100644
index 000000000000..4b9451ad0db9
--- /dev/null
+++ b/drivers/nvme/target/debugfs.c
@@ -0,0 +1,182 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DebugFS interface for the NVMe target.
+ * Copyright (c) 2022-2024 Shadow
+ */
+
+#include <linux/debugfs.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+
+#include "nvmet.h"
+#include "debugfs.h"
+
+struct dentry *nvmet_debugfs;
+
+#define NVMET_DEBUGFS_ATTR(field) \
+ static int field##_open(struct inode *inode, struct file *file) \
+ { return single_open(file, field##_show, inode->i_private); } \
+ \
+ static const struct file_operations field##_fops = { \
+ .open = field##_open, \
+ .read = seq_read, \
+ .release = single_release, \
+ }
+
+#define NVMET_DEBUGFS_RW_ATTR(field) \
+ static int field##_open(struct inode *inode, struct file *file) \
+ { return single_open(file, field##_show, inode->i_private); } \
+ \
+ static const struct file_operations field##_fops = { \
+ .open = field##_open, \
+ .read = seq_read, \
+ .write = field##_write, \
+ .release = single_release, \
+ }
+
+static int nvmet_ctrl_hostnqn_show(struct seq_file *m, void *p)
+{
+ struct nvmet_ctrl *ctrl = (struct nvmet_ctrl *)m->private;
+
+ seq_printf(m, "%s\n", ctrl->hostnqn);
+ return 0;
+}
+NVMET_DEBUGFS_ATTR(nvmet_ctrl_hostnqn);
+
+static int nvmet_ctrl_kato_show(struct seq_file *m, void *p)
+{
+ struct nvmet_ctrl *ctrl = (struct nvmet_ctrl *)m->private;
+
+ seq_printf(m, "%d\n", ctrl->kato);
+ return 0;
+}
+NVMET_DEBUGFS_ATTR(nvmet_ctrl_kato);
+
+static int nvmet_ctrl_port_show(struct seq_file *m, void *p)
+{
+ struct nvmet_ctrl *ctrl = (struct nvmet_ctrl *)m->private;
+
+ seq_printf(m, "%d\n", le16_to_cpu(ctrl->port->disc_addr.portid));
+ return 0;
+}
+NVMET_DEBUGFS_ATTR(nvmet_ctrl_port);
+
+static const char *const csts_state_names[] = {
+ [NVME_CSTS_RDY] = "ready",
+ [NVME_CSTS_CFS] = "fatal",
+ [NVME_CSTS_NSSRO] = "reset",
+ [NVME_CSTS_SHST_OCCUR] = "shutdown",
+ [NVME_CSTS_SHST_CMPLT] = "completed",
+ [NVME_CSTS_PP] = "paused",
+};
+
+static int nvmet_ctrl_state_show(struct seq_file *m, void *p)
+{
+ struct nvmet_ctrl *ctrl = (struct nvmet_ctrl *)m->private;
+ bool sep = false;
+ int i;
+
+ for (i = 0; i < 7; i++) {
+ int state = BIT(i);
+
+ if (!(ctrl->csts & state))
+ continue;
+ if (sep)
+ seq_puts(m, "|");
+ sep = true;
+ if (csts_state_names[state])
+ seq_puts(m, csts_state_names[state]);
+ else
+ seq_printf(m, "%d", state);
+ }
+ if (sep)
+ seq_printf(m, "\n");
+ return 0;
+}
+
+static ssize_t nvmet_ctrl_state_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct seq_file *m = file->private_data;
+ struct nvmet_ctrl *ctrl = m->private;
+ char reset[16];
+
+ if (count >= sizeof(reset))
+ return -EINVAL;
+ if (copy_from_user(reset, buf, count))
+ return -EFAULT;
+ if (!memcmp(reset, "fatal", 5))
+ nvmet_ctrl_fatal_error(ctrl);
+ else
+ return -EINVAL;
+ return count;
+}
+NVMET_DEBUGFS_RW_ATTR(nvmet_ctrl_state);
+
+int nvmet_debugfs_ctrl_setup(struct nvmet_ctrl *ctrl)
+{
+ char name[32];
+ struct dentry *parent = ctrl->subsys->debugfs_dir;
+ int ret;
+
+ if (!parent)
+ return -ENODEV;
+ snprintf(name, sizeof(name), "ctrl%d", ctrl->cntlid);
+ ctrl->debugfs_dir = debugfs_create_dir(name, parent);
+ if (IS_ERR(ctrl->debugfs_dir)) {
+ ret = PTR_ERR(ctrl->debugfs_dir);
+ ctrl->debugfs_dir = NULL;
+ return ret;
+ }
+ debugfs_create_file("port", S_IRUSR, ctrl->debugfs_dir, ctrl,
+ &nvmet_ctrl_port_fops);
+ debugfs_create_file("hostnqn", S_IRUSR, ctrl->debugfs_dir, ctrl,
+ &nvmet_ctrl_hostnqn_fops);
+ debugfs_create_file("kato", S_IRUSR, ctrl->debugfs_dir, ctrl,
+ &nvmet_ctrl_kato_fops);
+ debugfs_create_file("state", S_IRUSR | S_IWUSR, ctrl->debugfs_dir, ctrl,
+ &nvmet_ctrl_state_fops);
+ return 0;
+}
+
+void nvmet_debugfs_ctrl_free(struct nvmet_ctrl *ctrl)
+{
+ debugfs_remove_recursive(ctrl->debugfs_dir);
+}
+
+int nvmet_debugfs_subsys_setup(struct nvmet_subsys *subsys)
+{
+ int ret = 0;
+
+ subsys->debugfs_dir = debugfs_create_dir(subsys->subsysnqn,
+ nvmet_debugfs);
+ if (IS_ERR(subsys->debugfs_dir)) {
+ ret = PTR_ERR(subsys->debugfs_dir);
+ subsys->debugfs_dir = NULL;
+ }
+ return ret;
+}
+
+void nvmet_debugfs_subsys_free(struct nvmet_subsys *subsys)
+{
+ debugfs_remove_recursive(subsys->debugfs_dir);
+}
+
+int __init nvmet_init_debugfs(void)
+{
+ struct dentry *parent;
+
+ parent = debugfs_create_dir("nvmet", NULL);
+ if (IS_ERR(parent)) {
+ pr_warn("%s: failed to create debugfs directory\n", "nvmet");
+ return PTR_ERR(parent);
+ }
+ nvmet_debugfs = parent;
+ return 0;
+}
+
+void nvmet_exit_debugfs(void)
+{
+ debugfs_remove_recursive(nvmet_debugfs);
+}
diff --git a/drivers/nvme/target/debugfs.h b/drivers/nvme/target/debugfs.h
new file mode 100644
index 000000000000..ff09e5597614
--- /dev/null
+++ b/drivers/nvme/target/debugfs.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DebugFS interface for the NVMe target.
+ * Copyright (c) 2022-2024 Shadow
+ * Copyright (c) 2024 SUSE LLC
+ */
+#ifndef NVMET_DEBUGFS_H
+#define NVMET_DEBUGFS_H
+
+#include <linux/types.h>
+
+#ifdef CONFIG_NVME_TARGET_DEBUGFS
+int nvmet_debugfs_subsys_setup(struct nvmet_subsys *subsys);
+void nvmet_debugfs_subsys_free(struct nvmet_subsys *subsys);
+int nvmet_debugfs_ctrl_setup(struct nvmet_ctrl *ctrl);
+void nvmet_debugfs_ctrl_free(struct nvmet_ctrl *ctrl);
+
+int __init nvmet_init_debugfs(void);
+void nvmet_exit_debugfs(void);
+#else
+static inline int nvmet_debugfs_subsys_setup(struct nvmet_subsys *subsys)
+{
+ return 0;
+}
+static inline void nvmet_debugfs_subsys_free(struct nvmet_subsys *subsys){}
+
+static inline int nvmet_debugfs_ctrl_setup(struct nvmet_ctrl *ctrl)
+{
+ return 0;
+}
+static inline void nvmet_debugfs_ctrl_free(struct nvmet_ctrl *ctrl) {}
+
+static inline int __init nvmet_init_debugfs(void)
+{
+ return 0;
+}
+
+static inline void nvmet_exit_debugfs(void) {}
+
+#endif
+
+#endif // NVMET_DEBUGFS_H
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 765da2b932c5..f0371163cb26 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -233,7 +233,9 @@ struct nvmet_ctrl {
struct device *p2p_client;
struct radix_tree_root p2p_ns_map;
-
+#ifdef CONFIG_NVME_TARGET_DEBUGFS
+ struct dentry *debugfs_dir;
+#endif
spinlock_t error_lock;
u64 err_counter;
struct nvme_error_slot slots[NVMET_ERROR_LOG_SLOTS];
@@ -269,7 +271,9 @@ struct nvmet_subsys {
struct list_head hosts;
bool allow_any_host;
-
+#ifdef CONFIG_NVME_TARGET_DEBUGFS
+ struct dentry *debugfs_dir;
+#endif
u16 max_qid;
u64 ver;
--
2.35.3
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