drivers/block/rnbd/rnbd-srv-sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * RDMA Network Block Driver
   4  *
   5  * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
   6  * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
   7  * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
   8  */
   9 #undef pr_fmt
  10 #define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
  11
  12 #include <uapi/linux/limits.h>
  13 #include <linux/kobject.h>
  14 #include <linux/sysfs.h>
  15 #include <linux/stat.h>
  16 #include <linux/genhd.h>
  17 #include <linux/list.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/device.h>
  20
  21 #include "rnbd-srv.h"
  22
  23 static struct device *rnbd_dev;
  24 static struct class *rnbd_dev_class;
  25 static struct kobject *rnbd_devs_kobj;
  26
  27 static void rnbd_srv_dev_release(struct kobject *kobj)
  28 {
  29         struct rnbd_srv_dev *dev;
  30
  31         dev = container_of(kobj, struct rnbd_srv_dev, dev_kobj);
  32
  33         kfree(dev);
  34 }
  35
  36 static struct kobj_type dev_ktype = {
  37         .sysfs_ops = &kobj_sysfs_ops,
  38         .release = rnbd_srv_dev_release
  39 };
  40
  41 int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
  42                                struct block_device *bdev,
  43                                const char *dev_name)
  44 {
  45         struct kobject *bdev_kobj;
  46         int ret;
  47
  48         ret = kobject_init_and_add(&dev->dev_kobj, &dev_ktype,
  49                                    rnbd_devs_kobj, dev_name);
  50         if (ret)
  51                 return ret;
  52
  53         dev->dev_sessions_kobj = kobject_create_and_add("sessions",
  54                                                         &dev->dev_kobj);
  55         if (!dev->dev_sessions_kobj)
  56                 goto put_dev_kobj;
  57
  58         bdev_kobj = &disk_to_dev(bdev->bd_disk)->kobj;
  59         ret = sysfs_create_link(&dev->dev_kobj, bdev_kobj, "block_dev");
  60         if (ret)
  61                 goto put_sess_kobj;
  62
  63         return 0;
  64
  65 put_sess_kobj:
  66         kobject_put(dev->dev_sessions_kobj);
  67 put_dev_kobj:
  68         kobject_put(&dev->dev_kobj);
  69         return ret;
  70 }
  71
  72 void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev)
  73 {
  74         sysfs_remove_link(&dev->dev_kobj, "block_dev");
  75         kobject_del(dev->dev_sessions_kobj);
  76         kobject_put(dev->dev_sessions_kobj);
  77         kobject_del(&dev->dev_kobj);
  78         kobject_put(&dev->dev_kobj);
  79 }
  80
  81 static ssize_t read_only_show(struct kobject *kobj, struct kobj_attribute *attr,
  82                               char *page)
  83 {
  84         struct rnbd_srv_sess_dev *sess_dev;
  85
  86         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
  87
  88         return scnprintf(page, PAGE_SIZE, "%d\n",
  89                          !(sess_dev->open_flags & FMODE_WRITE));
  90 }
  91
  92 static struct kobj_attribute rnbd_srv_dev_session_ro_attr =
  93         __ATTR_RO(read_only);
  94
  95 static ssize_t access_mode_show(struct kobject *kobj,
  96                                 struct kobj_attribute *attr,
  97                                 char *page)
  98 {
  99         struct rnbd_srv_sess_dev *sess_dev;
 100
 101         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 102
 103         return scnprintf(page, PAGE_SIZE, "%s\n",
 104                          rnbd_access_mode_str(sess_dev->access_mode));
 105 }
 106
 107 static struct kobj_attribute rnbd_srv_dev_session_access_mode_attr =
 108         __ATTR_RO(access_mode);
 109
 110 static ssize_t mapping_path_show(struct kobject *kobj,
 111                                  struct kobj_attribute *attr, char *page)
 112 {
 113         struct rnbd_srv_sess_dev *sess_dev;
 114
 115         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 116
 117         return scnprintf(page, PAGE_SIZE, "%s\n", sess_dev->pathname);
 118 }
 119
 120 static struct kobj_attribute rnbd_srv_dev_session_mapping_path_attr =
 121         __ATTR_RO(mapping_path);
 122
 123 static struct attribute *rnbd_srv_default_dev_sessions_attrs[] = {
 124         &rnbd_srv_dev_session_access_mode_attr.attr,
 125         &rnbd_srv_dev_session_ro_attr.attr,
 126         &rnbd_srv_dev_session_mapping_path_attr.attr,
 127         NULL,
 128 };
 129
 130 static struct attribute_group rnbd_srv_default_dev_session_attr_group = {
 131         .attrs = rnbd_srv_default_dev_sessions_attrs,
 132 };
 133
 134 void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
 135 {
 136         sysfs_remove_group(&sess_dev->kobj,
 137                            &rnbd_srv_default_dev_session_attr_group);
 138
 139         kobject_del(&sess_dev->kobj);
 140         kobject_put(&sess_dev->kobj);
 141 }
 142
 143 static void rnbd_srv_sess_dev_release(struct kobject *kobj)
 144 {
 145         struct rnbd_srv_sess_dev *sess_dev;
 146
 147         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 148         rnbd_destroy_sess_dev(sess_dev);
 149 }
 150
 151 static struct kobj_type rnbd_srv_sess_dev_ktype = {
 152         .sysfs_ops      = &kobj_sysfs_ops,
 153         .release        = rnbd_srv_sess_dev_release,
 154 };
 155
 156 int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
 157 {
 158         int ret;
 159
 160         ret = kobject_init_and_add(&sess_dev->kobj, &rnbd_srv_sess_dev_ktype,
 161                                    sess_dev->dev->dev_sessions_kobj, "%s",
 162                                    sess_dev->sess->sessname);
 163         if (ret)
 164                 return ret;
 165
 166         ret = sysfs_create_group(&sess_dev->kobj,
 167                                  &rnbd_srv_default_dev_session_attr_group);
 168         if (ret)
 169                 goto err;
 170
 171         return 0;
 172
 173 err:
 174         kobject_put(&sess_dev->kobj);
 175
 176         return ret;
 177 }
 178
 179 int rnbd_srv_create_sysfs_files(void)
 180 {
 181         int err;
 182
 183         rnbd_dev_class = class_create(THIS_MODULE, "rnbd-server");
 184         if (IS_ERR(rnbd_dev_class))
 185                 return PTR_ERR(rnbd_dev_class);
 186
 187         rnbd_dev = device_create(rnbd_dev_class, NULL,
 188                                   MKDEV(0, 0), NULL, "ctl");
 189         if (IS_ERR(rnbd_dev)) {
 190                 err = PTR_ERR(rnbd_dev);
 191                 goto cls_destroy;
 192         }
 193         rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj);
 194         if (!rnbd_devs_kobj) {
 195                 err = -ENOMEM;
 196                 goto dev_destroy;
 197         }
 198
 199         return 0;
 200
 201 dev_destroy:
 202         device_destroy(rnbd_dev_class, MKDEV(0, 0));
 203 cls_destroy:
 204         class_destroy(rnbd_dev_class);
 205
 206         return err;
 207 }
 208
 209 void rnbd_srv_destroy_sysfs_files(void)
 210 {
 211         kobject_del(rnbd_devs_kobj);
 212         kobject_put(rnbd_devs_kobj);
 213         device_destroy(rnbd_dev_class, MKDEV(0, 0));
 214         class_destroy(rnbd_dev_class);
 215 }