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 <linux/kobject.h>
  13 #include <linux/sysfs.h>
  14 #include <linux/stat.h>
  15 #include <linux/list.h>
  16 #include <linux/moduleparam.h>
  17 #include <linux/device.h>
  18
  19 #include "rnbd-srv.h"
  20
  21 static struct device *rnbd_dev;
  22 static const struct class rnbd_dev_class = {
  23         .name = "rnbd-server",
  24 };
  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 const 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 {
  44         struct kobject *bdev_kobj;
  45         int ret;
  46
  47         ret = kobject_init_and_add(&dev->dev_kobj, &dev_ktype,
  48                                    rnbd_devs_kobj, "%pg", bdev);
  49         if (ret) {
  50                 kobject_put(&dev->dev_kobj);
  51                 return ret;
  52         }
  53
  54         dev->dev_sessions_kobj = kobject_create_and_add("sessions",
  55                                                         &dev->dev_kobj);
  56         if (!dev->dev_sessions_kobj) {
  57                 ret = -ENOMEM;
  58                 goto free_dev_kobj;
  59         }
  60
  61         bdev_kobj = &disk_to_dev(bdev->bd_disk)->kobj;
  62         ret = sysfs_create_link(&dev->dev_kobj, bdev_kobj, "block_dev");
  63         if (ret)
  64                 goto put_sess_kobj;
  65
  66         return 0;
  67
  68 put_sess_kobj:
  69         kobject_put(dev->dev_sessions_kobj);
  70 free_dev_kobj:
  71         kobject_del(&dev->dev_kobj);
  72         kobject_put(&dev->dev_kobj);
  73         return ret;
  74 }
  75
  76 void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev)
  77 {
  78         sysfs_remove_link(&dev->dev_kobj, "block_dev");
  79         kobject_del(dev->dev_sessions_kobj);
  80         kobject_put(dev->dev_sessions_kobj);
  81         kobject_del(&dev->dev_kobj);
  82         kobject_put(&dev->dev_kobj);
  83 }
  84
  85 static ssize_t read_only_show(struct kobject *kobj, struct kobj_attribute *attr,
  86                               char *page)
  87 {
  88         struct rnbd_srv_sess_dev *sess_dev;
  89
  90         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
  91
  92         return sysfs_emit(page, "%d\n", sess_dev->readonly);
  93 }
  94
  95 static struct kobj_attribute rnbd_srv_dev_session_ro_attr =
  96         __ATTR_RO(read_only);
  97
  98 static ssize_t access_mode_show(struct kobject *kobj,
  99                                 struct kobj_attribute *attr,
 100                                 char *page)
 101 {
 102         struct rnbd_srv_sess_dev *sess_dev;
 103
 104         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 105
 106         return sysfs_emit(page, "%s\n",
 107                           rnbd_access_modes[sess_dev->access_mode].str);
 108 }
 109
 110 static struct kobj_attribute rnbd_srv_dev_session_access_mode_attr =
 111         __ATTR_RO(access_mode);
 112
 113 static ssize_t mapping_path_show(struct kobject *kobj,
 114                                  struct kobj_attribute *attr, char *page)
 115 {
 116         struct rnbd_srv_sess_dev *sess_dev;
 117
 118         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 119
 120         return sysfs_emit(page, "%s\n", sess_dev->pathname);
 121 }
 122
 123 static struct kobj_attribute rnbd_srv_dev_session_mapping_path_attr =
 124         __ATTR_RO(mapping_path);
 125
 126 static ssize_t rnbd_srv_dev_session_force_close_show(struct kobject *kobj,
 127                                         struct kobj_attribute *attr, char *page)
 128 {
 129         return sysfs_emit(page, "Usage: echo 1 > %s\n",
 130                           attr->attr.name);
 131 }
 132
 133 static ssize_t rnbd_srv_dev_session_force_close_store(struct kobject *kobj,
 134                                         struct kobj_attribute *attr,
 135                                         const char *buf, size_t count)
 136 {
 137         struct rnbd_srv_sess_dev *sess_dev;
 138
 139         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 140
 141         if (!sysfs_streq(buf, "1")) {
 142                 rnbd_srv_err(sess_dev, "%s: invalid value: '%s'\n",
 143                               attr->attr.name, buf);
 144                 return -EINVAL;
 145         }
 146
 147         rnbd_srv_info(sess_dev, "force close requested\n");
 148         rnbd_srv_sess_dev_force_close(sess_dev, attr);
 149
 150         return count;
 151 }
 152
 153 static struct kobj_attribute rnbd_srv_dev_session_force_close_attr =
 154         __ATTR(force_close, 0644,
 155                rnbd_srv_dev_session_force_close_show,
 156                rnbd_srv_dev_session_force_close_store);
 157
 158 static struct attribute *rnbd_srv_default_dev_sessions_attrs[] = {
 159         &rnbd_srv_dev_session_access_mode_attr.attr,
 160         &rnbd_srv_dev_session_ro_attr.attr,
 161         &rnbd_srv_dev_session_mapping_path_attr.attr,
 162         &rnbd_srv_dev_session_force_close_attr.attr,
 163         NULL,
 164 };
 165
 166 static struct attribute_group rnbd_srv_default_dev_session_attr_group = {
 167         .attrs = rnbd_srv_default_dev_sessions_attrs,
 168 };
 169
 170 void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
 171 {
 172         sysfs_remove_group(&sess_dev->kobj,
 173                            &rnbd_srv_default_dev_session_attr_group);
 174
 175         kobject_del(&sess_dev->kobj);
 176         kobject_put(&sess_dev->kobj);
 177 }
 178
 179 static void rnbd_srv_sess_dev_release(struct kobject *kobj)
 180 {
 181         struct rnbd_srv_sess_dev *sess_dev;
 182
 183         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 184         rnbd_destroy_sess_dev(sess_dev, sess_dev->keep_id);
 185 }
 186
 187 static const struct kobj_type rnbd_srv_sess_dev_ktype = {
 188         .sysfs_ops      = &kobj_sysfs_ops,
 189         .release        = rnbd_srv_sess_dev_release,
 190 };
 191
 192 int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
 193 {
 194         int ret;
 195
 196         ret = kobject_init_and_add(&sess_dev->kobj, &rnbd_srv_sess_dev_ktype,
 197                                    sess_dev->dev->dev_sessions_kobj, "%s",
 198                                    sess_dev->sess->sessname);
 199         if (ret) {
 200                 kobject_put(&sess_dev->kobj);
 201                 return ret;
 202         }
 203
 204         ret = sysfs_create_group(&sess_dev->kobj,
 205                                  &rnbd_srv_default_dev_session_attr_group);
 206         if (ret) {
 207                 kobject_del(&sess_dev->kobj);
 208                 kobject_put(&sess_dev->kobj);
 209         }
 210
 211         return ret;
 212 }
 213
 214 int rnbd_srv_create_sysfs_files(void)
 215 {
 216         int err;
 217
 218         err = class_register(&rnbd_dev_class);
 219         if (err)
 220                 return err;
 221
 222         rnbd_dev = device_create(&rnbd_dev_class, NULL,
 223                                  MKDEV(0, 0), NULL, "ctl");
 224         if (IS_ERR(rnbd_dev)) {
 225                 err = PTR_ERR(rnbd_dev);
 226                 goto cls_destroy;
 227         }
 228         rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj);
 229         if (!rnbd_devs_kobj) {
 230                 err = -ENOMEM;
 231                 goto dev_destroy;
 232         }
 233
 234         return 0;
 235
 236 dev_destroy:
 237         device_destroy(&rnbd_dev_class, MKDEV(0, 0));
 238 cls_destroy:
 239         class_unregister(&rnbd_dev_class);
 240
 241         return err;
 242 }
 243
 244 void rnbd_srv_destroy_sysfs_files(void)
 245 {
 246         kobject_del(rnbd_devs_kobj);
 247         kobject_put(rnbd_devs_kobj);
 248         device_destroy(&rnbd_dev_class, MKDEV(0, 0));
 249         class_unregister(&rnbd_dev_class);
 250 }