Commit 8cee532f authored by Jack Wang's avatar Jack Wang Committed by Jason Gunthorpe

block/rnbd: server: sysfs interface functions

This is the sysfs interface to rnbd mapped devices on server side:

  /sys/class/rnbd-server/ctl/devices/<device_name>/
    |- block_dev
    |  *** link pointing to the corresponding block device sysfs entry
    |
    |- sessions/<session-name>/
    |  *** sessions directory
       |
       |- read_only
       |  *** is devices mapped as read only
       |
       |- mapping_path
          *** relative device path provided by the client during mapping

Link: https://lore.kernel.org/r/20200511135131.27580-23-danil.kipnis@cloud.ionos.comSigned-off-by: default avatarDanil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: default avatarJack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Acked-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent f0aad9ba
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* RDMA Network Block Driver
*
* Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
* Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
* Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
*/
#undef pr_fmt
#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
#include <uapi/linux/limits.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/stat.h>
#include <linux/genhd.h>
#include <linux/list.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include "rnbd-srv.h"
static struct device *rnbd_dev;
static struct class *rnbd_dev_class;
static struct kobject *rnbd_devs_kobj;
static void rnbd_srv_dev_release(struct kobject *kobj)
{
struct rnbd_srv_dev *dev;
dev = container_of(kobj, struct rnbd_srv_dev, dev_kobj);
kfree(dev);
}
static struct kobj_type dev_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.release = rnbd_srv_dev_release
};
int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
struct block_device *bdev,
const char *dev_name)
{
struct kobject *bdev_kobj;
int ret;
ret = kobject_init_and_add(&dev->dev_kobj, &dev_ktype,
rnbd_devs_kobj, dev_name);
if (ret)
return ret;
dev->dev_sessions_kobj = kobject_create_and_add("sessions",
&dev->dev_kobj);
if (!dev->dev_sessions_kobj)
goto put_dev_kobj;
bdev_kobj = &disk_to_dev(bdev->bd_disk)->kobj;
ret = sysfs_create_link(&dev->dev_kobj, bdev_kobj, "block_dev");
if (ret)
goto put_sess_kobj;
return 0;
put_sess_kobj:
kobject_put(dev->dev_sessions_kobj);
put_dev_kobj:
kobject_put(&dev->dev_kobj);
return ret;
}
void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev)
{
sysfs_remove_link(&dev->dev_kobj, "block_dev");
kobject_del(dev->dev_sessions_kobj);
kobject_put(dev->dev_sessions_kobj);
kobject_del(&dev->dev_kobj);
kobject_put(&dev->dev_kobj);
}
static ssize_t read_only_show(struct kobject *kobj, struct kobj_attribute *attr,
char *page)
{
struct rnbd_srv_sess_dev *sess_dev;
sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
return scnprintf(page, PAGE_SIZE, "%d\n",
!(sess_dev->open_flags & FMODE_WRITE));
}
static struct kobj_attribute rnbd_srv_dev_session_ro_attr =
__ATTR_RO(read_only);
static ssize_t access_mode_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *page)
{
struct rnbd_srv_sess_dev *sess_dev;
sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
return scnprintf(page, PAGE_SIZE, "%s\n",
rnbd_access_mode_str(sess_dev->access_mode));
}
static struct kobj_attribute rnbd_srv_dev_session_access_mode_attr =
__ATTR_RO(access_mode);
static ssize_t mapping_path_show(struct kobject *kobj,
struct kobj_attribute *attr, char *page)
{
struct rnbd_srv_sess_dev *sess_dev;
sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
return scnprintf(page, PAGE_SIZE, "%s\n", sess_dev->pathname);
}
static struct kobj_attribute rnbd_srv_dev_session_mapping_path_attr =
__ATTR_RO(mapping_path);
static struct attribute *rnbd_srv_default_dev_sessions_attrs[] = {
&rnbd_srv_dev_session_access_mode_attr.attr,
&rnbd_srv_dev_session_ro_attr.attr,
&rnbd_srv_dev_session_mapping_path_attr.attr,
NULL,
};
static struct attribute_group rnbd_srv_default_dev_session_attr_group = {
.attrs = rnbd_srv_default_dev_sessions_attrs,
};
void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
{
sysfs_remove_group(&sess_dev->kobj,
&rnbd_srv_default_dev_session_attr_group);
kobject_del(&sess_dev->kobj);
kobject_put(&sess_dev->kobj);
}
static void rnbd_srv_sess_dev_release(struct kobject *kobj)
{
struct rnbd_srv_sess_dev *sess_dev;
sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
rnbd_destroy_sess_dev(sess_dev);
}
static struct kobj_type rnbd_srv_sess_dev_ktype = {
.sysfs_ops = &kobj_sysfs_ops,
.release = rnbd_srv_sess_dev_release,
};
int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
{
int ret;
ret = kobject_init_and_add(&sess_dev->kobj, &rnbd_srv_sess_dev_ktype,
sess_dev->dev->dev_sessions_kobj, "%s",
sess_dev->sess->sessname);
if (ret)
return ret;
ret = sysfs_create_group(&sess_dev->kobj,
&rnbd_srv_default_dev_session_attr_group);
if (ret)
goto err;
return 0;
err:
kobject_put(&sess_dev->kobj);
return ret;
}
int rnbd_srv_create_sysfs_files(void)
{
int err;
rnbd_dev_class = class_create(THIS_MODULE, "rnbd-server");
if (IS_ERR(rnbd_dev_class))
return PTR_ERR(rnbd_dev_class);
rnbd_dev = device_create(rnbd_dev_class, NULL,
MKDEV(0, 0), NULL, "ctl");
if (IS_ERR(rnbd_dev)) {
err = PTR_ERR(rnbd_dev);
goto cls_destroy;
}
rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj);
if (!rnbd_devs_kobj) {
err = -ENOMEM;
goto dev_destroy;
}
return 0;
dev_destroy:
device_destroy(rnbd_dev_class, MKDEV(0, 0));
cls_destroy:
class_destroy(rnbd_dev_class);
return err;
}
void rnbd_srv_destroy_sysfs_files(void)
{
kobject_del(rnbd_devs_kobj);
kobject_put(rnbd_devs_kobj);
device_destroy(rnbd_dev_class, MKDEV(0, 0));
class_destroy(rnbd_dev_class);
}
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