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 kobject_put(&dev->dev_kobj); 52 return ret; 53 } 54 55 dev->dev_sessions_kobj = kobject_create_and_add("sessions", 56 &dev->dev_kobj); 57 if (!dev->dev_sessions_kobj) { 58 ret = -ENOMEM; 59 goto free_dev_kobj; 60 } 61 62 bdev_kobj = &disk_to_dev(bdev->bd_disk)->kobj; 63 ret = sysfs_create_link(&dev->dev_kobj, bdev_kobj, "block_dev"); 64 if (ret) 65 goto put_sess_kobj; 66 67 return 0; 68 69 put_sess_kobj: 70 kobject_put(dev->dev_sessions_kobj); 71 free_dev_kobj: 72 kobject_del(&dev->dev_kobj); 73 kobject_put(&dev->dev_kobj); 74 return ret; 75 } 76 77 void rnbd_srv_destroy_dev_sysfs(struct rnbd_srv_dev *dev) 78 { 79 sysfs_remove_link(&dev->dev_kobj, "block_dev"); 80 kobject_del(dev->dev_sessions_kobj); 81 kobject_put(dev->dev_sessions_kobj); 82 kobject_del(&dev->dev_kobj); 83 kobject_put(&dev->dev_kobj); 84 } 85 86 static ssize_t read_only_show(struct kobject *kobj, struct kobj_attribute *attr, 87 char *page) 88 { 89 struct rnbd_srv_sess_dev *sess_dev; 90 91 sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj); 92 93 return scnprintf(page, PAGE_SIZE, "%d\n", 94 !(sess_dev->open_flags & FMODE_WRITE)); 95 } 96 97 static struct kobj_attribute rnbd_srv_dev_session_ro_attr = 98 __ATTR_RO(read_only); 99 100 static ssize_t access_mode_show(struct kobject *kobj, 101 struct kobj_attribute *attr, 102 char *page) 103 { 104 struct rnbd_srv_sess_dev *sess_dev; 105 106 sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj); 107 108 return scnprintf(page, PAGE_SIZE, "%s\n", 109 rnbd_access_mode_str(sess_dev->access_mode)); 110 } 111 112 static struct kobj_attribute rnbd_srv_dev_session_access_mode_attr = 113 __ATTR_RO(access_mode); 114 115 static ssize_t mapping_path_show(struct kobject *kobj, 116 struct kobj_attribute *attr, char *page) 117 { 118 struct rnbd_srv_sess_dev *sess_dev; 119 120 sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj); 121 122 return scnprintf(page, PAGE_SIZE, "%s\n", sess_dev->pathname); 123 } 124 125 static struct kobj_attribute rnbd_srv_dev_session_mapping_path_attr = 126 __ATTR_RO(mapping_path); 127 128 static ssize_t rnbd_srv_dev_session_force_close_show(struct kobject *kobj, 129 struct kobj_attribute *attr, char *page) 130 { 131 return scnprintf(page, PAGE_SIZE, "Usage: echo 1 > %s\n", 132 attr->attr.name); 133 } 134 135 static ssize_t rnbd_srv_dev_session_force_close_store(struct kobject *kobj, 136 struct kobj_attribute *attr, 137 const char *buf, size_t count) 138 { 139 struct rnbd_srv_sess_dev *sess_dev; 140 141 sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj); 142 143 if (!sysfs_streq(buf, "1")) { 144 rnbd_srv_err(sess_dev, "%s: invalid value: '%s'\n", 145 attr->attr.name, buf); 146 return -EINVAL; 147 } 148 149 rnbd_srv_info(sess_dev, "force close requested\n"); 150 151 /* first remove sysfs itself to avoid deadlock */ 152 sysfs_remove_file_self(&sess_dev->kobj, &attr->attr); 153 rnbd_srv_sess_dev_force_close(sess_dev); 154 155 return count; 156 } 157 158 static struct kobj_attribute rnbd_srv_dev_session_force_close_attr = 159 __ATTR(force_close, 0644, 160 rnbd_srv_dev_session_force_close_show, 161 rnbd_srv_dev_session_force_close_store); 162 163 static struct attribute *rnbd_srv_default_dev_sessions_attrs[] = { 164 &rnbd_srv_dev_session_access_mode_attr.attr, 165 &rnbd_srv_dev_session_ro_attr.attr, 166 &rnbd_srv_dev_session_mapping_path_attr.attr, 167 &rnbd_srv_dev_session_force_close_attr.attr, 168 NULL, 169 }; 170 171 static struct attribute_group rnbd_srv_default_dev_session_attr_group = { 172 .attrs = rnbd_srv_default_dev_sessions_attrs, 173 }; 174 175 void rnbd_srv_destroy_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev) 176 { 177 sysfs_remove_group(&sess_dev->kobj, 178 &rnbd_srv_default_dev_session_attr_group); 179 180 kobject_del(&sess_dev->kobj); 181 kobject_put(&sess_dev->kobj); 182 } 183 184 static void rnbd_srv_sess_dev_release(struct kobject *kobj) 185 { 186 struct rnbd_srv_sess_dev *sess_dev; 187 188 sess_dev = container_of(kobj, struct rnbd_srv_sess_dev, kobj); 189 rnbd_destroy_sess_dev(sess_dev, sess_dev->keep_id); 190 } 191 192 static struct kobj_type rnbd_srv_sess_dev_ktype = { 193 .sysfs_ops = &kobj_sysfs_ops, 194 .release = rnbd_srv_sess_dev_release, 195 }; 196 197 int rnbd_srv_create_dev_session_sysfs(struct rnbd_srv_sess_dev *sess_dev) 198 { 199 int ret; 200 201 ret = kobject_init_and_add(&sess_dev->kobj, &rnbd_srv_sess_dev_ktype, 202 sess_dev->dev->dev_sessions_kobj, "%s", 203 sess_dev->sess->sessname); 204 if (ret) { 205 kobject_put(&sess_dev->kobj); 206 return ret; 207 } 208 209 ret = sysfs_create_group(&sess_dev->kobj, 210 &rnbd_srv_default_dev_session_attr_group); 211 if (ret) { 212 kobject_del(&sess_dev->kobj); 213 kobject_put(&sess_dev->kobj); 214 } 215 216 return ret; 217 } 218 219 int rnbd_srv_create_sysfs_files(void) 220 { 221 int err; 222 223 rnbd_dev_class = class_create(THIS_MODULE, "rnbd-server"); 224 if (IS_ERR(rnbd_dev_class)) 225 return PTR_ERR(rnbd_dev_class); 226 227 rnbd_dev = device_create(rnbd_dev_class, NULL, 228 MKDEV(0, 0), NULL, "ctl"); 229 if (IS_ERR(rnbd_dev)) { 230 err = PTR_ERR(rnbd_dev); 231 goto cls_destroy; 232 } 233 rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj); 234 if (!rnbd_devs_kobj) { 235 err = -ENOMEM; 236 goto dev_destroy; 237 } 238 239 return 0; 240 241 dev_destroy: 242 device_destroy(rnbd_dev_class, MKDEV(0, 0)); 243 cls_destroy: 244 class_destroy(rnbd_dev_class); 245 246 return err; 247 } 248 249 void rnbd_srv_destroy_sysfs_files(void) 250 { 251 kobject_del(rnbd_devs_kobj); 252 kobject_put(rnbd_devs_kobj); 253 device_destroy(rnbd_dev_class, MKDEV(0, 0)); 254 class_destroy(rnbd_dev_class); 255 } 256