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. |
Peter Korsgaard | 02fbe5e | 2012-04-17 12:13:18 +0200 | [diff] [blame] | 10 | * By default, all devices are named after the name of the device, |
| 11 | * owned by root and have a default mode of 0600. Subsystems can |
| 12 | * 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; |
Al Viro | 2c9ede5 | 2011-07-23 20:24:48 -0400 | [diff] [blame] | 43 | umode_t mode; /* 0 => delete */ |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 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 | |
Al Viro | fbd48a6 | 2011-07-24 10:47:56 -0400 | [diff] [blame] | 145 | static int dev_mkdir(const char *name, umode_t mode) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 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 | |
Jeff Layton | 1ac12b4 | 2012-12-11 12:10:06 -0500 | [diff] [blame] | 151 | dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY); |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 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; |
Al Viro | 921a165 | 2012-07-20 01:15:31 +0400 | [diff] [blame] | 159 | done_path_create(&path, dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 160 | return err; |
| 161 | } |
| 162 | |
| 163 | static int create_path(const char *nodepath) |
| 164 | { |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 165 | char *path; |
| 166 | char *s; |
Al Viro | 9d108d2 | 2011-07-27 22:27:33 -0400 | [diff] [blame] | 167 | int err = 0; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 168 | |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 169 | /* parent directories do not exist, create them */ |
| 170 | path = kstrdup(nodepath, GFP_KERNEL); |
| 171 | if (!path) |
| 172 | return -ENOMEM; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 173 | |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 174 | s = path; |
| 175 | for (;;) { |
| 176 | s = strchr(s, '/'); |
| 177 | if (!s) |
| 178 | break; |
| 179 | s[0] = '\0'; |
| 180 | err = dev_mkdir(path, 0755); |
| 181 | if (err && err != -EEXIST) |
| 182 | break; |
| 183 | s[0] = '/'; |
| 184 | s++; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 185 | } |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 186 | kfree(path); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 187 | return err; |
| 188 | } |
| 189 | |
Al Viro | fbd48a6 | 2011-07-24 10:47:56 -0400 | [diff] [blame] | 190 | static int handle_create(const char *nodename, umode_t mode, struct device *dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 191 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 192 | struct dentry *dentry; |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 193 | struct path path; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 194 | int err; |
| 195 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 196 | dentry = kern_path_create(AT_FDCWD, nodename, &path, 0); |
| 197 | if (dentry == ERR_PTR(-ENOENT)) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 198 | create_path(nodename); |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 199 | dentry = kern_path_create(AT_FDCWD, nodename, &path, 0); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 200 | } |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 201 | if (IS_ERR(dentry)) |
| 202 | return PTR_ERR(dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 203 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 204 | err = vfs_mknod(path.dentry->d_inode, |
| 205 | dentry, mode, dev->devt); |
| 206 | if (!err) { |
| 207 | struct iattr newattrs; |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 208 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 209 | /* fixup possibly umasked mode */ |
| 210 | newattrs.ia_mode = mode; |
| 211 | newattrs.ia_valid = ATTR_MODE; |
| 212 | mutex_lock(&dentry->d_inode->i_mutex); |
| 213 | notify_change(dentry, &newattrs); |
| 214 | mutex_unlock(&dentry->d_inode->i_mutex); |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 215 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 216 | /* mark as kernel-created inode */ |
| 217 | dentry->d_inode->i_private = &thread; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 218 | } |
Al Viro | 921a165 | 2012-07-20 01:15:31 +0400 | [diff] [blame] | 219 | done_path_create(&path, dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 220 | return err; |
| 221 | } |
| 222 | |
| 223 | static int dev_rmdir(const char *name) |
| 224 | { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 225 | struct path parent; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 226 | struct dentry *dentry; |
| 227 | int err; |
| 228 | |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 229 | dentry = kern_path_locked(name, &parent); |
| 230 | if (IS_ERR(dentry)) |
| 231 | return PTR_ERR(dentry); |
| 232 | if (dentry->d_inode) { |
| 233 | if (dentry->d_inode->i_private == &thread) |
| 234 | err = vfs_rmdir(parent.dentry->d_inode, dentry); |
| 235 | else |
| 236 | err = -EPERM; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 237 | } else { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 238 | err = -ENOENT; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 239 | } |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 240 | dput(dentry); |
| 241 | mutex_unlock(&parent.dentry->d_inode->i_mutex); |
| 242 | path_put(&parent); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 243 | return err; |
| 244 | } |
| 245 | |
| 246 | static int delete_path(const char *nodepath) |
| 247 | { |
| 248 | const char *path; |
| 249 | int err = 0; |
| 250 | |
| 251 | path = kstrdup(nodepath, GFP_KERNEL); |
| 252 | if (!path) |
| 253 | return -ENOMEM; |
| 254 | |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 255 | for (;;) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 256 | char *base; |
| 257 | |
| 258 | base = strrchr(path, '/'); |
| 259 | if (!base) |
| 260 | break; |
| 261 | base[0] = '\0'; |
| 262 | err = dev_rmdir(path); |
| 263 | if (err) |
| 264 | break; |
| 265 | } |
| 266 | |
| 267 | kfree(path); |
| 268 | return err; |
| 269 | } |
| 270 | |
| 271 | static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat) |
| 272 | { |
| 273 | /* did we create it */ |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 274 | if (inode->i_private != &thread) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 275 | return 0; |
| 276 | |
| 277 | /* does the dev_t match */ |
| 278 | if (is_blockdev(dev)) { |
| 279 | if (!S_ISBLK(stat->mode)) |
| 280 | return 0; |
| 281 | } else { |
| 282 | if (!S_ISCHR(stat->mode)) |
| 283 | return 0; |
| 284 | } |
| 285 | if (stat->rdev != dev->devt) |
| 286 | return 0; |
| 287 | |
| 288 | /* ours */ |
| 289 | return 1; |
| 290 | } |
| 291 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 292 | static int handle_remove(const char *nodename, struct device *dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 293 | { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 294 | struct path parent; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 295 | struct dentry *dentry; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 296 | int deleted = 1; |
| 297 | int err; |
| 298 | |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 299 | dentry = kern_path_locked(nodename, &parent); |
| 300 | if (IS_ERR(dentry)) |
| 301 | return PTR_ERR(dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 302 | |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 303 | if (dentry->d_inode) { |
| 304 | struct kstat stat; |
| 305 | err = vfs_getattr(parent.mnt, dentry, &stat); |
| 306 | if (!err && dev_mynode(dev, dentry->d_inode, &stat)) { |
| 307 | struct iattr newattrs; |
| 308 | /* |
| 309 | * before unlinking this node, reset permissions |
| 310 | * of possible references like hardlinks |
| 311 | */ |
Eric W. Biederman | 91fa2cc | 2012-04-25 04:25:35 -0700 | [diff] [blame] | 312 | newattrs.ia_uid = GLOBAL_ROOT_UID; |
| 313 | newattrs.ia_gid = GLOBAL_ROOT_GID; |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 314 | newattrs.ia_mode = stat.mode & ~0777; |
| 315 | newattrs.ia_valid = |
| 316 | ATTR_UID|ATTR_GID|ATTR_MODE; |
| 317 | mutex_lock(&dentry->d_inode->i_mutex); |
| 318 | notify_change(dentry, &newattrs); |
| 319 | mutex_unlock(&dentry->d_inode->i_mutex); |
| 320 | err = vfs_unlink(parent.dentry->d_inode, dentry); |
| 321 | if (!err || err == -ENOENT) |
| 322 | deleted = 1; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 323 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 324 | } else { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 325 | err = -ENOENT; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 326 | } |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 327 | dput(dentry); |
| 328 | mutex_unlock(&parent.dentry->d_inode->i_mutex); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 329 | |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 330 | path_put(&parent); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 331 | if (deleted && strchr(nodename, '/')) |
| 332 | delete_path(nodename); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 333 | return err; |
| 334 | } |
| 335 | |
| 336 | /* |
| 337 | * If configured, or requested by the commandline, devtmpfs will be |
| 338 | * auto-mounted after the kernel mounted the root filesystem. |
| 339 | */ |
Kay Sievers | 073120c | 2009-10-28 19:51:17 +0100 | [diff] [blame] | 340 | int devtmpfs_mount(const char *mntdir) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 341 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 342 | int err; |
| 343 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 344 | if (!mount_dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 345 | return 0; |
| 346 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 347 | if (!thread) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 348 | return 0; |
| 349 | |
Kay Sievers | 073120c | 2009-10-28 19:51:17 +0100 | [diff] [blame] | 350 | err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 351 | if (err) |
| 352 | printk(KERN_INFO "devtmpfs: error mounting %i\n", err); |
| 353 | else |
| 354 | printk(KERN_INFO "devtmpfs: mounted\n"); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 355 | return err; |
| 356 | } |
| 357 | |
Arnaud Lacombe | f9e0b15 | 2011-07-21 13:16:19 -0400 | [diff] [blame] | 358 | static DECLARE_COMPLETION(setup_done); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 359 | |
Al Viro | fbd48a6 | 2011-07-24 10:47:56 -0400 | [diff] [blame] | 360 | static int handle(const char *name, umode_t mode, struct device *dev) |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 361 | { |
| 362 | if (mode) |
| 363 | return handle_create(name, mode, dev); |
| 364 | else |
| 365 | return handle_remove(name, dev); |
| 366 | } |
| 367 | |
| 368 | static int devtmpfsd(void *p) |
| 369 | { |
| 370 | char options[] = "mode=0755"; |
| 371 | int *err = p; |
| 372 | *err = sys_unshare(CLONE_NEWNS); |
| 373 | if (*err) |
| 374 | goto out; |
| 375 | *err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options); |
| 376 | if (*err) |
| 377 | goto out; |
| 378 | sys_chdir("/.."); /* will traverse into overmounted root */ |
| 379 | sys_chroot("."); |
| 380 | complete(&setup_done); |
| 381 | while (1) { |
| 382 | spin_lock(&req_lock); |
| 383 | while (requests) { |
| 384 | struct req *req = requests; |
| 385 | requests = NULL; |
| 386 | spin_unlock(&req_lock); |
| 387 | while (req) { |
Al Viro | e13889b | 2011-07-25 14:15:50 -0400 | [diff] [blame] | 388 | struct req *next = req->next; |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 389 | req->err = handle(req->name, req->mode, req->dev); |
| 390 | complete(&req->done); |
Al Viro | e13889b | 2011-07-25 14:15:50 -0400 | [diff] [blame] | 391 | req = next; |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 392 | } |
| 393 | spin_lock(&req_lock); |
| 394 | } |
Kautuk Consul | 65e6757 | 2011-11-15 14:52:34 -0800 | [diff] [blame] | 395 | __set_current_state(TASK_INTERRUPTIBLE); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 396 | spin_unlock(&req_lock); |
| 397 | schedule(); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 398 | } |
| 399 | return 0; |
| 400 | out: |
| 401 | complete(&setup_done); |
| 402 | return *err; |
| 403 | } |
| 404 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 405 | /* |
| 406 | * Create devtmpfs instance, driver-core devices will add their device |
| 407 | * nodes here. |
| 408 | */ |
| 409 | int __init devtmpfs_init(void) |
| 410 | { |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 411 | int err = register_filesystem(&dev_fs_type); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 412 | if (err) { |
| 413 | printk(KERN_ERR "devtmpfs: unable to register devtmpfs " |
| 414 | "type %i\n", err); |
| 415 | return err; |
| 416 | } |
| 417 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 418 | thread = kthread_run(devtmpfsd, &err, "kdevtmpfs"); |
| 419 | if (!IS_ERR(thread)) { |
| 420 | wait_for_completion(&setup_done); |
| 421 | } else { |
| 422 | err = PTR_ERR(thread); |
| 423 | thread = NULL; |
| 424 | } |
| 425 | |
| 426 | if (err) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 427 | printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err); |
| 428 | unregister_filesystem(&dev_fs_type); |
| 429 | return err; |
| 430 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 431 | |
| 432 | printk(KERN_INFO "devtmpfs: initialized\n"); |
| 433 | return 0; |
| 434 | } |