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 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 147 | struct dentry *dentry; |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 148 | struct path path; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 149 | int err; |
| 150 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 151 | dentry = kern_path_create(AT_FDCWD, name, &path, 1); |
| 152 | if (IS_ERR(dentry)) |
| 153 | return PTR_ERR(dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 154 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 155 | err = vfs_mkdir(path.dentry->d_inode, dentry, mode); |
| 156 | if (!err) |
| 157 | /* mark as kernel-created inode */ |
| 158 | dentry->d_inode->i_private = &thread; |
| 159 | dput(dentry); |
| 160 | mutex_unlock(&path.dentry->d_inode->i_mutex); |
| 161 | path_put(&path); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 162 | return err; |
| 163 | } |
| 164 | |
| 165 | static int create_path(const char *nodepath) |
| 166 | { |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 167 | char *path; |
| 168 | char *s; |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 169 | int err; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 170 | |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 171 | /* parent directories do not exist, create them */ |
| 172 | path = kstrdup(nodepath, GFP_KERNEL); |
| 173 | if (!path) |
| 174 | return -ENOMEM; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 175 | |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 176 | s = path; |
| 177 | for (;;) { |
| 178 | s = strchr(s, '/'); |
| 179 | if (!s) |
| 180 | break; |
| 181 | s[0] = '\0'; |
| 182 | err = dev_mkdir(path, 0755); |
| 183 | if (err && err != -EEXIST) |
| 184 | break; |
| 185 | s[0] = '/'; |
| 186 | s++; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 187 | } |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 188 | kfree(path); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 189 | return err; |
| 190 | } |
| 191 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 192 | 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] | 193 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 194 | struct dentry *dentry; |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 195 | struct path path; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 196 | int err; |
| 197 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 198 | dentry = kern_path_create(AT_FDCWD, nodename, &path, 0); |
| 199 | if (dentry == ERR_PTR(-ENOENT)) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 200 | create_path(nodename); |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 201 | dentry = kern_path_create(AT_FDCWD, nodename, &path, 0); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 202 | } |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 203 | if (IS_ERR(dentry)) |
| 204 | return PTR_ERR(dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 205 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 206 | err = vfs_mknod(path.dentry->d_inode, |
| 207 | dentry, mode, dev->devt); |
| 208 | if (!err) { |
| 209 | struct iattr newattrs; |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 210 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 211 | /* fixup possibly umasked mode */ |
| 212 | newattrs.ia_mode = mode; |
| 213 | newattrs.ia_valid = ATTR_MODE; |
| 214 | mutex_lock(&dentry->d_inode->i_mutex); |
| 215 | notify_change(dentry, &newattrs); |
| 216 | mutex_unlock(&dentry->d_inode->i_mutex); |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 217 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 218 | /* mark as kernel-created inode */ |
| 219 | dentry->d_inode->i_private = &thread; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 220 | } |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 221 | dput(dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 222 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 223 | mutex_unlock(&path.dentry->d_inode->i_mutex); |
| 224 | path_put(&path); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 225 | return err; |
| 226 | } |
| 227 | |
| 228 | static int dev_rmdir(const char *name) |
| 229 | { |
| 230 | struct nameidata nd; |
| 231 | struct dentry *dentry; |
| 232 | int err; |
| 233 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 234 | err = kern_path_parent(name, &nd); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 235 | if (err) |
| 236 | return err; |
| 237 | |
| 238 | mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); |
| 239 | dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len); |
| 240 | if (!IS_ERR(dentry)) { |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 241 | if (dentry->d_inode) { |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 242 | if (dentry->d_inode->i_private == &thread) |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 243 | err = vfs_rmdir(nd.path.dentry->d_inode, |
| 244 | dentry); |
| 245 | else |
| 246 | err = -EPERM; |
| 247 | } else { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 248 | err = -ENOENT; |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 249 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 250 | dput(dentry); |
| 251 | } else { |
| 252 | err = PTR_ERR(dentry); |
| 253 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 254 | |
Kay Sievers | 015bf43 | 2009-10-28 19:51:26 +0100 | [diff] [blame] | 255 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 256 | path_put(&nd.path); |
| 257 | return err; |
| 258 | } |
| 259 | |
| 260 | static int delete_path(const char *nodepath) |
| 261 | { |
| 262 | const char *path; |
| 263 | int err = 0; |
| 264 | |
| 265 | path = kstrdup(nodepath, GFP_KERNEL); |
| 266 | if (!path) |
| 267 | return -ENOMEM; |
| 268 | |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 269 | for (;;) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 270 | char *base; |
| 271 | |
| 272 | base = strrchr(path, '/'); |
| 273 | if (!base) |
| 274 | break; |
| 275 | base[0] = '\0'; |
| 276 | err = dev_rmdir(path); |
| 277 | if (err) |
| 278 | break; |
| 279 | } |
| 280 | |
| 281 | kfree(path); |
| 282 | return err; |
| 283 | } |
| 284 | |
| 285 | static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat) |
| 286 | { |
| 287 | /* did we create it */ |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 288 | if (inode->i_private != &thread) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 289 | return 0; |
| 290 | |
| 291 | /* does the dev_t match */ |
| 292 | if (is_blockdev(dev)) { |
| 293 | if (!S_ISBLK(stat->mode)) |
| 294 | return 0; |
| 295 | } else { |
| 296 | if (!S_ISCHR(stat->mode)) |
| 297 | return 0; |
| 298 | } |
| 299 | if (stat->rdev != dev->devt) |
| 300 | return 0; |
| 301 | |
| 302 | /* ours */ |
| 303 | return 1; |
| 304 | } |
| 305 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 306 | static int handle_remove(const char *nodename, struct device *dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 307 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 308 | struct nameidata nd; |
| 309 | struct dentry *dentry; |
| 310 | struct kstat stat; |
| 311 | int deleted = 1; |
| 312 | int err; |
| 313 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 314 | err = kern_path_parent(nodename, &nd); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 315 | if (err) |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 316 | return err; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 317 | |
| 318 | mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); |
| 319 | dentry = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len); |
| 320 | if (!IS_ERR(dentry)) { |
| 321 | if (dentry->d_inode) { |
| 322 | err = vfs_getattr(nd.path.mnt, dentry, &stat); |
| 323 | if (!err && dev_mynode(dev, dentry->d_inode, &stat)) { |
Kay Sievers | 5e31d76 | 2010-01-13 14:16:36 +0100 | [diff] [blame] | 324 | struct iattr newattrs; |
| 325 | /* |
| 326 | * before unlinking this node, reset permissions |
| 327 | * of possible references like hardlinks |
| 328 | */ |
| 329 | newattrs.ia_uid = 0; |
| 330 | newattrs.ia_gid = 0; |
| 331 | newattrs.ia_mode = stat.mode & ~0777; |
| 332 | newattrs.ia_valid = |
| 333 | ATTR_UID|ATTR_GID|ATTR_MODE; |
| 334 | mutex_lock(&dentry->d_inode->i_mutex); |
| 335 | notify_change(dentry, &newattrs); |
| 336 | mutex_unlock(&dentry->d_inode->i_mutex); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 337 | err = vfs_unlink(nd.path.dentry->d_inode, |
| 338 | dentry); |
| 339 | if (!err || err == -ENOENT) |
| 340 | deleted = 1; |
| 341 | } |
| 342 | } else { |
| 343 | err = -ENOENT; |
| 344 | } |
| 345 | dput(dentry); |
| 346 | } else { |
| 347 | err = PTR_ERR(dentry); |
| 348 | } |
| 349 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
| 350 | |
| 351 | path_put(&nd.path); |
| 352 | if (deleted && strchr(nodename, '/')) |
| 353 | delete_path(nodename); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 354 | return err; |
| 355 | } |
| 356 | |
| 357 | /* |
| 358 | * If configured, or requested by the commandline, devtmpfs will be |
| 359 | * auto-mounted after the kernel mounted the root filesystem. |
| 360 | */ |
Kay Sievers | 073120c | 2009-10-28 19:51:17 +0100 | [diff] [blame] | 361 | int devtmpfs_mount(const char *mntdir) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 362 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 363 | int err; |
| 364 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 365 | if (!mount_dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 366 | return 0; |
| 367 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 368 | if (!thread) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 369 | return 0; |
| 370 | |
Kay Sievers | 073120c | 2009-10-28 19:51:17 +0100 | [diff] [blame] | 371 | err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 372 | if (err) |
| 373 | printk(KERN_INFO "devtmpfs: error mounting %i\n", err); |
| 374 | else |
| 375 | printk(KERN_INFO "devtmpfs: mounted\n"); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 376 | return err; |
| 377 | } |
| 378 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 379 | static __initdata DECLARE_COMPLETION(setup_done); |
| 380 | |
| 381 | static int handle(const char *name, mode_t mode, struct device *dev) |
| 382 | { |
| 383 | if (mode) |
| 384 | return handle_create(name, mode, dev); |
| 385 | else |
| 386 | return handle_remove(name, dev); |
| 387 | } |
| 388 | |
| 389 | static int devtmpfsd(void *p) |
| 390 | { |
| 391 | char options[] = "mode=0755"; |
| 392 | int *err = p; |
| 393 | *err = sys_unshare(CLONE_NEWNS); |
| 394 | if (*err) |
| 395 | goto out; |
| 396 | *err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options); |
| 397 | if (*err) |
| 398 | goto out; |
| 399 | sys_chdir("/.."); /* will traverse into overmounted root */ |
| 400 | sys_chroot("."); |
| 401 | complete(&setup_done); |
| 402 | while (1) { |
| 403 | spin_lock(&req_lock); |
| 404 | while (requests) { |
| 405 | struct req *req = requests; |
| 406 | requests = NULL; |
| 407 | spin_unlock(&req_lock); |
| 408 | while (req) { |
| 409 | req->err = handle(req->name, req->mode, req->dev); |
| 410 | complete(&req->done); |
| 411 | req = req->next; |
| 412 | } |
| 413 | spin_lock(&req_lock); |
| 414 | } |
| 415 | set_current_state(TASK_INTERRUPTIBLE); |
| 416 | spin_unlock(&req_lock); |
| 417 | schedule(); |
| 418 | __set_current_state(TASK_RUNNING); |
| 419 | } |
| 420 | return 0; |
| 421 | out: |
| 422 | complete(&setup_done); |
| 423 | return *err; |
| 424 | } |
| 425 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 426 | /* |
| 427 | * Create devtmpfs instance, driver-core devices will add their device |
| 428 | * nodes here. |
| 429 | */ |
| 430 | int __init devtmpfs_init(void) |
| 431 | { |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 432 | int err = register_filesystem(&dev_fs_type); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 433 | if (err) { |
| 434 | printk(KERN_ERR "devtmpfs: unable to register devtmpfs " |
| 435 | "type %i\n", err); |
| 436 | return err; |
| 437 | } |
| 438 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 439 | thread = kthread_run(devtmpfsd, &err, "kdevtmpfs"); |
| 440 | if (!IS_ERR(thread)) { |
| 441 | wait_for_completion(&setup_done); |
| 442 | } else { |
| 443 | err = PTR_ERR(thread); |
| 444 | thread = NULL; |
| 445 | } |
| 446 | |
| 447 | if (err) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 448 | printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err); |
| 449 | unregister_filesystem(&dev_fs_type); |
| 450 | return err; |
| 451 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 452 | |
| 453 | printk(KERN_INFO "devtmpfs: initialized\n"); |
| 454 | return 0; |
| 455 | } |