Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 1 | /* |
| 2 | * devtmpfs - kernel-maintained tmpfs-based /dev |
| 3 | * |
| 4 | * Copyright (C) 2009, Kay Sievers <kay.sievers@vrfy.org> |
| 5 | * |
| 6 | * During bootup, before any driver core device is registered, |
| 7 | * devtmpfs, a tmpfs-based filesystem is created. Every driver-core |
| 8 | * device which requests a device node, will add a node in this |
Kay Sievers | e454cea | 2009-09-18 23:01:12 +0200 | [diff] [blame] | 9 | * filesystem. |
| 10 | * By default, all devices are named after the the name of the |
| 11 | * device, owned by root and have a default mode of 0600. Subsystems |
| 12 | * can overwrite the default setting if needed. |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 13 | */ |
| 14 | |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/syscalls.h> |
| 17 | #include <linux/mount.h> |
| 18 | #include <linux/device.h> |
| 19 | #include <linux/genhd.h> |
| 20 | #include <linux/namei.h> |
| 21 | #include <linux/fs.h> |
| 22 | #include <linux/shmem_fs.h> |
Peter Korsgaard | da5e4ef | 2010-03-16 21:55:21 +0100 | [diff] [blame] | 23 | #include <linux/ramfs.h> |
Kay Sievers | e454cea | 2009-09-18 23:01:12 +0200 | [diff] [blame] | 24 | #include <linux/sched.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 25 | #include <linux/slab.h> |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 26 | #include <linux/kthread.h> |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 27 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 28 | static struct task_struct *thread; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 29 | |
| 30 | #if defined CONFIG_DEVTMPFS_MOUNT |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 31 | static int mount_dev = 1; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 32 | #else |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 33 | static int mount_dev; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 34 | #endif |
| 35 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 36 | static DEFINE_SPINLOCK(req_lock); |
| 37 | |
| 38 | static struct req { |
| 39 | struct req *next; |
| 40 | struct completion done; |
| 41 | int err; |
| 42 | const char *name; |
| 43 | mode_t mode; /* 0 => delete */ |
| 44 | struct device *dev; |
| 45 | } *requests; |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 46 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 47 | static int __init mount_param(char *str) |
| 48 | { |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 49 | mount_dev = simple_strtoul(str, NULL, 0); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 50 | return 1; |
| 51 | } |
| 52 | __setup("devtmpfs.mount=", mount_param); |
| 53 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 54 | static struct dentry *dev_mount(struct file_system_type *fs_type, int flags, |
| 55 | const char *dev_name, void *data) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 56 | { |
Peter Korsgaard | da5e4ef | 2010-03-16 21:55:21 +0100 | [diff] [blame] | 57 | #ifdef CONFIG_TMPFS |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 58 | return mount_single(fs_type, flags, data, shmem_fill_super); |
Peter Korsgaard | da5e4ef | 2010-03-16 21:55:21 +0100 | [diff] [blame] | 59 | #else |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 60 | return mount_single(fs_type, flags, data, ramfs_fill_super); |
Peter Korsgaard | da5e4ef | 2010-03-16 21:55:21 +0100 | [diff] [blame] | 61 | #endif |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 62 | } |
| 63 | |
| 64 | static struct file_system_type dev_fs_type = { |
| 65 | .name = "devtmpfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 66 | .mount = dev_mount, |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 67 | .kill_sb = kill_litter_super, |
| 68 | }; |
| 69 | |
| 70 | #ifdef CONFIG_BLOCK |
| 71 | static inline int is_blockdev(struct device *dev) |
| 72 | { |
| 73 | return dev->class == &block_class; |
| 74 | } |
| 75 | #else |
| 76 | static inline int is_blockdev(struct device *dev) { return 0; } |
| 77 | #endif |
| 78 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 79 | int devtmpfs_create_node(struct device *dev) |
| 80 | { |
| 81 | const char *tmp = NULL; |
| 82 | struct req req; |
| 83 | |
| 84 | if (!thread) |
| 85 | return 0; |
| 86 | |
| 87 | req.mode = 0; |
| 88 | req.name = device_get_devnode(dev, &req.mode, &tmp); |
| 89 | if (!req.name) |
| 90 | return -ENOMEM; |
| 91 | |
| 92 | if (req.mode == 0) |
| 93 | req.mode = 0600; |
| 94 | if (is_blockdev(dev)) |
| 95 | req.mode |= S_IFBLK; |
| 96 | else |
| 97 | req.mode |= S_IFCHR; |
| 98 | |
| 99 | req.dev = dev; |
| 100 | |
| 101 | init_completion(&req.done); |
| 102 | |
| 103 | spin_lock(&req_lock); |
| 104 | req.next = requests; |
| 105 | requests = &req; |
| 106 | spin_unlock(&req_lock); |
| 107 | |
| 108 | wake_up_process(thread); |
| 109 | wait_for_completion(&req.done); |
| 110 | |
| 111 | kfree(tmp); |
| 112 | |
| 113 | return req.err; |
| 114 | } |
| 115 | |
| 116 | int devtmpfs_delete_node(struct device *dev) |
| 117 | { |
| 118 | const char *tmp = NULL; |
| 119 | struct req req; |
| 120 | |
| 121 | if (!thread) |
| 122 | return 0; |
| 123 | |
| 124 | req.name = device_get_devnode(dev, NULL, &tmp); |
| 125 | if (!req.name) |
| 126 | return -ENOMEM; |
| 127 | |
| 128 | req.mode = 0; |
| 129 | req.dev = dev; |
| 130 | |
| 131 | init_completion(&req.done); |
| 132 | |
| 133 | spin_lock(&req_lock); |
| 134 | req.next = requests; |
| 135 | requests = &req; |
| 136 | spin_unlock(&req_lock); |
| 137 | |
| 138 | wake_up_process(thread); |
| 139 | wait_for_completion(&req.done); |
| 140 | |
| 141 | kfree(tmp); |
| 142 | return req.err; |
| 143 | } |
| 144 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 145 | static int dev_mkdir(const char *name, mode_t mode) |
| 146 | { |
| 147 | struct nameidata nd; |
| 148 | struct dentry *dentry; |
| 149 | int err; |
| 150 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 151 | err = kern_path_parent(name, &nd); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 152 | if (err) |
| 153 | return err; |
| 154 | |
| 155 | dentry = lookup_create(&nd, 1); |
| 156 | if (!IS_ERR(dentry)) { |
| 157 | err = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode); |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 158 | if (!err) |
| 159 | /* mark as kernel-created inode */ |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 160 | dentry->d_inode->i_private = &thread; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 161 | dput(dentry); |
| 162 | } else { |
| 163 | err = PTR_ERR(dentry); |
| 164 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 165 | |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 166 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 167 | path_put(&nd.path); |
| 168 | return err; |
| 169 | } |
| 170 | |
| 171 | static int create_path(const char *nodepath) |
| 172 | { |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 173 | int err; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 174 | |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 175 | err = dev_mkdir(nodepath, 0755); |
| 176 | if (err == -ENOENT) { |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 177 | char *path; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 178 | char *s; |
| 179 | |
| 180 | /* parent directories do not exist, create them */ |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 181 | path = kstrdup(nodepath, GFP_KERNEL); |
Kay Sievers | 8042273 | 2009-12-22 22:25:16 +0100 | [diff] [blame] | 182 | if (!path) { |
| 183 | err = -ENOMEM; |
| 184 | goto out; |
| 185 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 186 | s = path; |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 187 | for (;;) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 188 | s = strchr(s, '/'); |
| 189 | if (!s) |
| 190 | break; |
| 191 | s[0] = '\0'; |
| 192 | err = dev_mkdir(path, 0755); |
| 193 | if (err && err != -EEXIST) |
| 194 | break; |
| 195 | s[0] = '/'; |
| 196 | s++; |
| 197 | } |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 198 | kfree(path); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 199 | } |
Kay Sievers | 8042273 | 2009-12-22 22:25:16 +0100 | [diff] [blame] | 200 | out: |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 201 | return err; |
| 202 | } |
| 203 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 204 | static int handle_create(const char *nodename, mode_t mode, struct device *dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 205 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 206 | struct nameidata nd; |
| 207 | struct dentry *dentry; |
| 208 | int err; |
| 209 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 210 | err = kern_path_parent(nodename, &nd); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 211 | if (err == -ENOENT) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 212 | create_path(nodename); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 213 | err = kern_path_parent(nodename, &nd); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 214 | } |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 215 | if (err) |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 216 | return err; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 217 | |
| 218 | dentry = lookup_create(&nd, 0); |
| 219 | if (!IS_ERR(dentry)) { |
| 220 | err = vfs_mknod(nd.path.dentry->d_inode, |
| 221 | dentry, mode, dev->devt); |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 222 | if (!err) { |
| 223 | struct iattr newattrs; |
| 224 | |
| 225 | /* fixup possibly umasked mode */ |
| 226 | newattrs.ia_mode = mode; |
| 227 | newattrs.ia_valid = ATTR_MODE; |
| 228 | mutex_lock(&dentry->d_inode->i_mutex); |
| 229 | notify_change(dentry, &newattrs); |
| 230 | mutex_unlock(&dentry->d_inode->i_mutex); |
| 231 | |
| 232 | /* mark as kernel-created inode */ |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 233 | dentry->d_inode->i_private = &thread; |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 234 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 235 | dput(dentry); |
| 236 | } else { |
| 237 | err = PTR_ERR(dentry); |
| 238 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 239 | |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 240 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 241 | path_put(&nd.path); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 242 | return err; |
| 243 | } |
| 244 | |
| 245 | static int dev_rmdir(const char *name) |
| 246 | { |
| 247 | struct nameidata nd; |
| 248 | struct dentry *dentry; |
| 249 | int err; |
| 250 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 251 | err = kern_path_parent(name, &nd); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 252 | if (err) |
| 253 | return err; |
| 254 | |
| 255 | mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); |
| 256 | dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len); |
| 257 | if (!IS_ERR(dentry)) { |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 258 | if (dentry->d_inode) { |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 259 | if (dentry->d_inode->i_private == &thread) |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 260 | err = vfs_rmdir(nd.path.dentry->d_inode, |
| 261 | dentry); |
| 262 | else |
| 263 | err = -EPERM; |
| 264 | } else { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 265 | err = -ENOENT; |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 266 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 267 | dput(dentry); |
| 268 | } else { |
| 269 | err = PTR_ERR(dentry); |
| 270 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 271 | |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 272 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 273 | path_put(&nd.path); |
| 274 | return err; |
| 275 | } |
| 276 | |
| 277 | static int delete_path(const char *nodepath) |
| 278 | { |
| 279 | const char *path; |
| 280 | int err = 0; |
| 281 | |
| 282 | path = kstrdup(nodepath, GFP_KERNEL); |
| 283 | if (!path) |
| 284 | return -ENOMEM; |
| 285 | |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 286 | for (;;) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 287 | char *base; |
| 288 | |
| 289 | base = strrchr(path, '/'); |
| 290 | if (!base) |
| 291 | break; |
| 292 | base[0] = '\0'; |
| 293 | err = dev_rmdir(path); |
| 294 | if (err) |
| 295 | break; |
| 296 | } |
| 297 | |
| 298 | kfree(path); |
| 299 | return err; |
| 300 | } |
| 301 | |
| 302 | static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat) |
| 303 | { |
| 304 | /* did we create it */ |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 305 | if (inode->i_private != &thread) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 306 | return 0; |
| 307 | |
| 308 | /* does the dev_t match */ |
| 309 | if (is_blockdev(dev)) { |
| 310 | if (!S_ISBLK(stat->mode)) |
| 311 | return 0; |
| 312 | } else { |
| 313 | if (!S_ISCHR(stat->mode)) |
| 314 | return 0; |
| 315 | } |
| 316 | if (stat->rdev != dev->devt) |
| 317 | return 0; |
| 318 | |
| 319 | /* ours */ |
| 320 | return 1; |
| 321 | } |
| 322 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 323 | static int handle_remove(const char *nodename, struct device *dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 324 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 325 | struct nameidata nd; |
| 326 | struct dentry *dentry; |
| 327 | struct kstat stat; |
| 328 | int deleted = 1; |
| 329 | int err; |
| 330 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 331 | err = kern_path_parent(nodename, &nd); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 332 | if (err) |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 333 | return err; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 334 | |
| 335 | mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); |
| 336 | dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len); |
| 337 | if (!IS_ERR(dentry)) { |
| 338 | if (dentry->d_inode) { |
| 339 | err = vfs_getattr(nd.path.mnt, dentry, &stat); |
| 340 | if (!err && dev_mynode(dev, dentry->d_inode, &stat)) { |
Kay Sievers | 5e31d76 | 2010-01-13 14:16:36 +0100 | [diff] [blame] | 341 | struct iattr newattrs; |
| 342 | /* |
| 343 | * before unlinking this node, reset permissions |
| 344 | * of possible references like hardlinks |
| 345 | */ |
| 346 | newattrs.ia_uid = 0; |
| 347 | newattrs.ia_gid = 0; |
| 348 | newattrs.ia_mode = stat.mode & ~0777; |
| 349 | newattrs.ia_valid = |
| 350 | ATTR_UID|ATTR_GID|ATTR_MODE; |
| 351 | mutex_lock(&dentry->d_inode->i_mutex); |
| 352 | notify_change(dentry, &newattrs); |
| 353 | mutex_unlock(&dentry->d_inode->i_mutex); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 354 | err = vfs_unlink(nd.path.dentry->d_inode, |
| 355 | dentry); |
| 356 | if (!err || err == -ENOENT) |
| 357 | deleted = 1; |
| 358 | } |
| 359 | } else { |
| 360 | err = -ENOENT; |
| 361 | } |
| 362 | dput(dentry); |
| 363 | } else { |
| 364 | err = PTR_ERR(dentry); |
| 365 | } |
| 366 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
| 367 | |
| 368 | path_put(&nd.path); |
| 369 | if (deleted && strchr(nodename, '/')) |
| 370 | delete_path(nodename); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 371 | return err; |
| 372 | } |
| 373 | |
| 374 | /* |
| 375 | * If configured, or requested by the commandline, devtmpfs will be |
| 376 | * auto-mounted after the kernel mounted the root filesystem. |
| 377 | */ |
Kay Sievers | 073120c | 2009-10-28 19:51:17 +0100 | [diff] [blame] | 378 | int devtmpfs_mount(const char *mntdir) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 379 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 380 | int err; |
| 381 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 382 | if (!mount_dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 383 | return 0; |
| 384 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 385 | if (!thread) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 386 | return 0; |
| 387 | |
Kay Sievers | 073120c | 2009-10-28 19:51:17 +0100 | [diff] [blame] | 388 | err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 389 | if (err) |
| 390 | printk(KERN_INFO "devtmpfs: error mounting %i\n", err); |
| 391 | else |
| 392 | printk(KERN_INFO "devtmpfs: mounted\n"); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 393 | return err; |
| 394 | } |
| 395 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 396 | static __initdata DECLARE_COMPLETION(setup_done); |
| 397 | |
| 398 | static int handle(const char *name, mode_t mode, struct device *dev) |
| 399 | { |
| 400 | if (mode) |
| 401 | return handle_create(name, mode, dev); |
| 402 | else |
| 403 | return handle_remove(name, dev); |
| 404 | } |
| 405 | |
| 406 | static int devtmpfsd(void *p) |
| 407 | { |
| 408 | char options[] = "mode=0755"; |
| 409 | int *err = p; |
| 410 | *err = sys_unshare(CLONE_NEWNS); |
| 411 | if (*err) |
| 412 | goto out; |
| 413 | *err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options); |
| 414 | if (*err) |
| 415 | goto out; |
| 416 | sys_chdir("/.."); /* will traverse into overmounted root */ |
| 417 | sys_chroot("."); |
| 418 | complete(&setup_done); |
| 419 | while (1) { |
| 420 | spin_lock(&req_lock); |
| 421 | while (requests) { |
| 422 | struct req *req = requests; |
| 423 | requests = NULL; |
| 424 | spin_unlock(&req_lock); |
| 425 | while (req) { |
| 426 | req->err = handle(req->name, req->mode, req->dev); |
| 427 | complete(&req->done); |
| 428 | req = req->next; |
| 429 | } |
| 430 | spin_lock(&req_lock); |
| 431 | } |
| 432 | set_current_state(TASK_INTERRUPTIBLE); |
| 433 | spin_unlock(&req_lock); |
| 434 | schedule(); |
| 435 | __set_current_state(TASK_RUNNING); |
| 436 | } |
| 437 | return 0; |
| 438 | out: |
| 439 | complete(&setup_done); |
| 440 | return *err; |
| 441 | } |
| 442 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 443 | /* |
| 444 | * Create devtmpfs instance, driver-core devices will add their device |
| 445 | * nodes here. |
| 446 | */ |
| 447 | int __init devtmpfs_init(void) |
| 448 | { |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 449 | int err = register_filesystem(&dev_fs_type); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 450 | if (err) { |
| 451 | printk(KERN_ERR "devtmpfs: unable to register devtmpfs " |
| 452 | "type %i\n", err); |
| 453 | return err; |
| 454 | } |
| 455 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame^] | 456 | thread = kthread_run(devtmpfsd, &err, "kdevtmpfs"); |
| 457 | if (!IS_ERR(thread)) { |
| 458 | wait_for_completion(&setup_done); |
| 459 | } else { |
| 460 | err = PTR_ERR(thread); |
| 461 | thread = NULL; |
| 462 | } |
| 463 | |
| 464 | if (err) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 465 | printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err); |
| 466 | unregister_filesystem(&dev_fs_type); |
| 467 | return err; |
| 468 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 469 | |
| 470 | printk(KERN_INFO "devtmpfs: initialized\n"); |
| 471 | return 0; |
| 472 | } |