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 struct class *rnbd_dev_class;
  23 static struct kobject *rnbd_devs_kobj;
  24
  25 static void rnbd_srv_dev_release(struct kobject *kobj)
  26 {
  27         struct rnbd_srv_dev *dev;
  28
  29         dev = container_of(kobj, struct rnbd_srv_dev, dev_kobj);
  30
  31         kfree(dev);
  32 }
  33
  34 static struct kobj_type dev_ktype = {
  35         .sysfs_ops = &kobj_sysfs_ops,
  36         .release = rnbd_srv_dev_release
  37 };
  38
  39 int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev,
  40                                struct block_device *bdev)
  41 {
  42         struct kobject *bdev_kobj;
  43         int ret;
  44
  45         ret = kobject_init_and_add(&dev->dev_kobj, &dev_ktype,
  46                                    rnbd_devs_kobj, "%pg", bdev);
  47         if (ret) {
  48                 kobject_put(&dev->dev_kobj);
  49                 return ret;
  50         }
  51
  52         dev->dev_sessions_kobj = kobject_create_and_add("sessions",
  53                                                         &dev->dev_kobj);
  54         if (!dev->dev_sessions_kobj) {
  55                 ret = -ENOMEM;
  56                 goto free_dev_kobj;
  57         }
  58
  59         bdev_kobj = &disk_to_dev(bdev->bd_disk)->kobj;
  60         ret = sysfs_create_link(&dev->dev_kobj, bdev_kobj, "block_dev");
  61         if (ret)
  62                 goto put_sess_kobj;
  63
  64         return 0;
  65
  66 put_sess_kobj:
  67         kobject_put(dev->dev_sessions_kobj);
  68 free_dev_kobj:
  69         kobject_del(&dev->dev_kobj);
  70         kobject_put(&dev->dev_kobj);
  71         return ret;
  72 }
  73
  74 void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev)
  75 {
  76         sysfs_remove_link(&dev->dev_kobj, "block_dev");
  77         kobject_del(dev->dev_sessions_kobj);
  78         kobject_put(dev->dev_sessions_kobj);
  79         kobject_del(&dev->dev_kobj);
  80         kobject_put(&dev->dev_kobj);
  81 }
  82
  83 static ssize_t read_only_show(struct kobject *kobj, struct kobj_attribute *attr,
  84                               char *page)
  85 {
  86         struct rnbd_srv_sess_dev *sess_dev;
  87
  88         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
  89
  90         return sysfs_emit(page, "%d\n",
  91                           !(sess_dev->open_flags & FMODE_WRITE));
  92 }
  93
  94 static struct kobj_attribute rnbd_srv_dev_session_ro_attr =
  95         __ATTR_RO(read_only);
  96
  97 static ssize_t access_mode_show(struct kobject *kobj,
  98                                 struct kobj_attribute *attr,
  99                                 char *page)
 100 {
 101         struct rnbd_srv_sess_dev *sess_dev;
 102
 103         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 104
 105         return sysfs_emit(page, "%s\n",
 106                           rnbd_access_modes[sess_dev->access_mode].str);
 107 }
 108
 109 static struct kobj_attribute rnbd_srv_dev_session_access_mode_attr =
 110         __ATTR_RO(access_mode);
 111
 112 static ssize_t mapping_path_show(struct kobject *kobj,
 113                                  struct kobj_attribute *attr, char *page)
 114 {
 115         struct rnbd_srv_sess_dev *sess_dev;
 116
 117         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 118
 119         return sysfs_emit(page, "%s\n", sess_dev->pathname);
 120 }
 121
 122 static struct kobj_attribute rnbd_srv_dev_session_mapping_path_attr =
 123         __ATTR_RO(mapping_path);
 124
 125 static ssize_t rnbd_srv_dev_session_force_close_show(struct kobject *kobj,
 126                                         struct kobj_attribute *attr, char *page)
 127 {
 128         return sysfs_emit(page, "Usage: echo 1 > %s\n",
 129                           attr->attr.name);
 130 }
 131
 132 static ssize_t rnbd_srv_dev_session_force_close_store(struct kobject *kobj,
 133                                         struct kobj_attribute *attr,
 134                                         const char *buf, size_t count)
 135 {
 136         struct rnbd_srv_sess_dev *sess_dev;
 137
 138         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 139
 140         if (!sysfs_streq(buf, "1")) {
 141                 rnbd_srv_err(sess_dev, "%s: invalid value: '%s'\n",
 142                               attr->attr.name, buf);
 143                 return -EINVAL;
 144         }
 145
 146         rnbd_srv_info(sess_dev, "force close requested\n");
 147         rnbd_srv_sess_dev_force_close(sess_dev, attr);
 148
 149         return count;
 150 }
 151
 152 static struct kobj_attribute rnbd_srv_dev_session_force_close_attr =
 153         __ATTR(force_close, 0644,
 154                rnbd_srv_dev_session_force_close_show,
 155                rnbd_srv_dev_session_force_close_store);
 156
 157 static struct attribute *rnbd_srv_default_dev_sessions_attrs[] = {
 158         &rnbd_srv_dev_session_access_mode_attr.attr,
 159         &rnbd_srv_dev_session_ro_attr.attr,
 160         &rnbd_srv_dev_session_mapping_path_attr.attr,
 161         &rnbd_srv_dev_session_force_close_attr.attr,
 162         NULL,
 163 };
 164
 165 static struct attribute_group rnbd_srv_default_dev_session_attr_group = {
 166         .attrs = rnbd_srv_default_dev_sessions_attrs,
 167 };
 168
 169 void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
 170 {
 171         sysfs_remove_group(&sess_dev->kobj,
 172                            &rnbd_srv_default_dev_session_attr_group);
 173
 174         kobject_del(&sess_dev->kobj);
 175         kobject_put(&sess_dev->kobj);
 176 }
 177
 178 static void rnbd_srv_sess_dev_release(struct kobject *kobj)
 179 {
 180         struct rnbd_srv_sess_dev *sess_dev;
 181
 182         sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj);
 183         rnbd_destroy_sess_dev(sess_dev, sess_dev->keep_id);
 184 }
 185
 186 static struct kobj_type rnbd_srv_sess_dev_ktype = {
 187         .sysfs_ops      = &kobj_sysfs_ops,
 188         .release        = rnbd_srv_sess_dev_release,
 189 };
 190
 191 int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev)
 192 {
 193         int ret;
 194
 195         ret = kobject_init_and_add(&sess_dev->kobj, &rnbd_srv_sess_dev_ktype,
 196                                    sess_dev->dev->dev_sessions_kobj, "%s",
 197                                    sess_dev->sess->sessname);
 198         if (ret) {
 199                 kobject_put(&sess_dev->kobj);
 200                 return ret;
 201         }
 202
 203         ret = sysfs_create_group(&sess_dev->kobj,
 204                                  &rnbd_srv_default_dev_session_attr_group);
 205         if (ret) {
 206                 kobject_del(&sess_dev->kobj);
 207                 kobject_put(&sess_dev->kobj);
 208         }
 209
 210         return ret;
 211 }
 212
 213 int rnbd_srv_create_sysfs_files(void)
 214 {
 215         int err;
 216
 217         rnbd_dev_class = class_create("rnbd-server");
 218         if (IS_ERR(rnbd_dev_class))
 219                 return PTR_ERR(rnbd_dev_class);
 220
 221         rnbd_dev = device_create(rnbd_dev_class, NULL,
 222                                   MKDEV(0, 0), NULL, "ctl");
 223         if (IS_ERR(rnbd_dev)) {
 224                 err = PTR_ERR(rnbd_dev);
 225                 goto cls_destroy;
 226         }
 227         rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj);
 228         if (!rnbd_devs_kobj) {
 229                 err = -ENOMEM;
 230                 goto dev_destroy;
 231         }
 232
 233         return 0;
 234
 235 dev_destroy:
 236         device_destroy(rnbd_dev_class, MKDEV(0, 0));
 237 cls_destroy:
 238         class_destroy(rnbd_dev_class);
 239
 240         return err;
 241 }
 242
 243 void rnbd_srv_destroy_sysfs_files(void)
 244 {
 245         kobject_del(rnbd_devs_kobj);
 246         kobject_put(rnbd_devs_kobj);
 247         device_destroy(rnbd_dev_class, MKDEV(0, 0));
 248         class_destroy(rnbd_dev_class);
 249 }