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> |
Greg Kroah-Hartman | c3a3042 | 2013-04-10 09:00:15 -0700 | [diff] [blame] | 27 | #include "base.h" |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 28 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 29 | static struct task_struct *thread; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 30 | |
| 31 | #if defined CONFIG_DEVTMPFS_MOUNT |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 32 | static int mount_dev = 1; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 33 | #else |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 34 | static int mount_dev; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 35 | #endif |
| 36 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 37 | static DEFINE_SPINLOCK(req_lock); |
| 38 | |
| 39 | static struct req { |
| 40 | struct req *next; |
| 41 | struct completion done; |
| 42 | int err; |
| 43 | const char *name; |
Al Viro | 2c9ede5 | 2011-07-23 20:24:48 -0400 | [diff] [blame] | 44 | umode_t mode; /* 0 => delete */ |
Greg Kroah-Hartman | 4e4098a | 2013-04-11 11:43:29 -0700 | [diff] [blame] | 45 | kuid_t uid; |
| 46 | kgid_t gid; |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 47 | struct device *dev; |
| 48 | } *requests; |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 49 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 50 | static int __init mount_param(char *str) |
| 51 | { |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 52 | mount_dev = simple_strtoul(str, NULL, 0); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 53 | return 1; |
| 54 | } |
| 55 | __setup("devtmpfs.mount=", mount_param); |
| 56 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 57 | static struct dentry *dev_mount(struct file_system_type *fs_type, int flags, |
| 58 | const char *dev_name, void *data) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 59 | { |
Peter Korsgaard | da5e4ef | 2010-03-16 21:55:21 +0100 | [diff] [blame] | 60 | #ifdef CONFIG_TMPFS |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 61 | return mount_single(fs_type, flags, data, shmem_fill_super); |
Peter Korsgaard | da5e4ef | 2010-03-16 21:55:21 +0100 | [diff] [blame] | 62 | #else |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 63 | return mount_single(fs_type, flags, data, ramfs_fill_super); |
Peter Korsgaard | da5e4ef | 2010-03-16 21:55:21 +0100 | [diff] [blame] | 64 | #endif |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 65 | } |
| 66 | |
| 67 | static struct file_system_type dev_fs_type = { |
| 68 | .name = "devtmpfs", |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 69 | .mount = dev_mount, |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 70 | .kill_sb = kill_litter_super, |
| 71 | }; |
| 72 | |
| 73 | #ifdef CONFIG_BLOCK |
| 74 | static inline int is_blockdev(struct device *dev) |
| 75 | { |
| 76 | return dev->class == &block_class; |
| 77 | } |
| 78 | #else |
| 79 | static inline int is_blockdev(struct device *dev) { return 0; } |
| 80 | #endif |
| 81 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 82 | int devtmpfs_create_node(struct device *dev) |
| 83 | { |
| 84 | const char *tmp = NULL; |
| 85 | struct req req; |
| 86 | |
| 87 | if (!thread) |
| 88 | return 0; |
| 89 | |
| 90 | req.mode = 0; |
Greg Kroah-Hartman | 4e4098a | 2013-04-11 11:43:29 -0700 | [diff] [blame] | 91 | req.uid = GLOBAL_ROOT_UID; |
| 92 | req.gid = GLOBAL_ROOT_GID; |
Kay Sievers | 3c2670e | 2013-04-06 09:56:00 -0700 | [diff] [blame] | 93 | req.name = device_get_devnode(dev, &req.mode, &req.uid, &req.gid, &tmp); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 94 | if (!req.name) |
| 95 | return -ENOMEM; |
| 96 | |
| 97 | if (req.mode == 0) |
| 98 | req.mode = 0600; |
| 99 | if (is_blockdev(dev)) |
| 100 | req.mode |= S_IFBLK; |
| 101 | else |
| 102 | req.mode |= S_IFCHR; |
| 103 | |
| 104 | req.dev = dev; |
| 105 | |
| 106 | init_completion(&req.done); |
| 107 | |
| 108 | spin_lock(&req_lock); |
| 109 | req.next = requests; |
| 110 | requests = &req; |
| 111 | spin_unlock(&req_lock); |
| 112 | |
| 113 | wake_up_process(thread); |
| 114 | wait_for_completion(&req.done); |
| 115 | |
| 116 | kfree(tmp); |
| 117 | |
| 118 | return req.err; |
| 119 | } |
| 120 | |
| 121 | int devtmpfs_delete_node(struct device *dev) |
| 122 | { |
| 123 | const char *tmp = NULL; |
| 124 | struct req req; |
| 125 | |
| 126 | if (!thread) |
| 127 | return 0; |
| 128 | |
Kay Sievers | 3c2670e | 2013-04-06 09:56:00 -0700 | [diff] [blame] | 129 | req.name = device_get_devnode(dev, NULL, NULL, NULL, &tmp); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 130 | if (!req.name) |
| 131 | return -ENOMEM; |
| 132 | |
| 133 | req.mode = 0; |
| 134 | req.dev = dev; |
| 135 | |
| 136 | init_completion(&req.done); |
| 137 | |
| 138 | spin_lock(&req_lock); |
| 139 | req.next = requests; |
| 140 | requests = &req; |
| 141 | spin_unlock(&req_lock); |
| 142 | |
| 143 | wake_up_process(thread); |
| 144 | wait_for_completion(&req.done); |
| 145 | |
| 146 | kfree(tmp); |
| 147 | return req.err; |
| 148 | } |
| 149 | |
Al Viro | fbd48a6 | 2011-07-24 10:47:56 -0400 | [diff] [blame] | 150 | static int dev_mkdir(const char *name, umode_t mode) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 151 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 152 | struct dentry *dentry; |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 153 | struct path path; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 154 | int err; |
| 155 | |
Jeff Layton | 1ac12b4 | 2012-12-11 12:10:06 -0500 | [diff] [blame] | 156 | dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY); |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 157 | if (IS_ERR(dentry)) |
| 158 | return PTR_ERR(dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 159 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 160 | err = vfs_mkdir(path.dentry->d_inode, dentry, mode); |
| 161 | if (!err) |
| 162 | /* mark as kernel-created inode */ |
| 163 | dentry->d_inode->i_private = &thread; |
Al Viro | 921a165 | 2012-07-20 01:15:31 +0400 | [diff] [blame] | 164 | done_path_create(&path, dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 165 | return err; |
| 166 | } |
| 167 | |
| 168 | static int create_path(const char *nodepath) |
| 169 | { |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 170 | char *path; |
| 171 | char *s; |
Al Viro | 9d108d2 | 2011-07-27 22:27:33 -0400 | [diff] [blame] | 172 | int err = 0; |
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 | /* parent directories do not exist, create them */ |
| 175 | path = kstrdup(nodepath, GFP_KERNEL); |
| 176 | if (!path) |
| 177 | return -ENOMEM; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 178 | |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 179 | s = path; |
| 180 | for (;;) { |
| 181 | s = strchr(s, '/'); |
| 182 | if (!s) |
| 183 | break; |
| 184 | s[0] = '\0'; |
| 185 | err = dev_mkdir(path, 0755); |
| 186 | if (err && err != -EEXIST) |
| 187 | break; |
| 188 | s[0] = '/'; |
| 189 | s++; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 190 | } |
Al Viro | 5da4e68 | 2011-06-27 16:37:12 -0400 | [diff] [blame] | 191 | kfree(path); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 192 | return err; |
| 193 | } |
| 194 | |
Greg Kroah-Hartman | 4e4098a | 2013-04-11 11:43:29 -0700 | [diff] [blame] | 195 | static int handle_create(const char *nodename, umode_t mode, kuid_t uid, |
| 196 | kgid_t gid, struct device *dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 197 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 198 | struct dentry *dentry; |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 199 | struct path path; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 200 | int err; |
| 201 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 202 | dentry = kern_path_create(AT_FDCWD, nodename, &path, 0); |
| 203 | if (dentry == ERR_PTR(-ENOENT)) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 204 | create_path(nodename); |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 205 | dentry = kern_path_create(AT_FDCWD, nodename, &path, 0); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 206 | } |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 207 | if (IS_ERR(dentry)) |
| 208 | return PTR_ERR(dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 209 | |
Kay Sievers | 3c2670e | 2013-04-06 09:56:00 -0700 | [diff] [blame] | 210 | err = vfs_mknod(path.dentry->d_inode, dentry, mode, dev->devt); |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 211 | if (!err) { |
| 212 | struct iattr newattrs; |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 213 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 214 | newattrs.ia_mode = mode; |
Greg Kroah-Hartman | 4e4098a | 2013-04-11 11:43:29 -0700 | [diff] [blame] | 215 | newattrs.ia_uid = uid; |
| 216 | newattrs.ia_gid = gid; |
Kay Sievers | 3c2670e | 2013-04-06 09:56:00 -0700 | [diff] [blame] | 217 | newattrs.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID; |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 218 | mutex_lock(&dentry->d_inode->i_mutex); |
| 219 | notify_change(dentry, &newattrs); |
| 220 | mutex_unlock(&dentry->d_inode->i_mutex); |
Kay Sievers | 0092699 | 2009-10-28 19:50:57 +0100 | [diff] [blame] | 221 | |
Al Viro | 69753a0 | 2011-06-27 16:35:45 -0400 | [diff] [blame] | 222 | /* mark as kernel-created inode */ |
| 223 | dentry->d_inode->i_private = &thread; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 224 | } |
Al Viro | 921a165 | 2012-07-20 01:15:31 +0400 | [diff] [blame] | 225 | done_path_create(&path, dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 226 | return err; |
| 227 | } |
| 228 | |
| 229 | static int dev_rmdir(const char *name) |
| 230 | { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 231 | struct path parent; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 232 | struct dentry *dentry; |
| 233 | int err; |
| 234 | |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 235 | dentry = kern_path_locked(name, &parent); |
| 236 | if (IS_ERR(dentry)) |
| 237 | return PTR_ERR(dentry); |
| 238 | if (dentry->d_inode) { |
| 239 | if (dentry->d_inode->i_private == &thread) |
| 240 | err = vfs_rmdir(parent.dentry->d_inode, dentry); |
| 241 | else |
| 242 | err = -EPERM; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 243 | } else { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 244 | err = -ENOENT; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 245 | } |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 246 | dput(dentry); |
| 247 | mutex_unlock(&parent.dentry->d_inode->i_mutex); |
| 248 | path_put(&parent); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 249 | return err; |
| 250 | } |
| 251 | |
| 252 | static int delete_path(const char *nodepath) |
| 253 | { |
| 254 | const char *path; |
| 255 | int err = 0; |
| 256 | |
| 257 | path = kstrdup(nodepath, GFP_KERNEL); |
| 258 | if (!path) |
| 259 | return -ENOMEM; |
| 260 | |
Kay Sievers | ed413ae | 2009-10-28 19:51:06 +0100 | [diff] [blame] | 261 | for (;;) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 262 | char *base; |
| 263 | |
| 264 | base = strrchr(path, '/'); |
| 265 | if (!base) |
| 266 | break; |
| 267 | base[0] = '\0'; |
| 268 | err = dev_rmdir(path); |
| 269 | if (err) |
| 270 | break; |
| 271 | } |
| 272 | |
| 273 | kfree(path); |
| 274 | return err; |
| 275 | } |
| 276 | |
| 277 | static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat) |
| 278 | { |
| 279 | /* did we create it */ |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 280 | if (inode->i_private != &thread) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 281 | return 0; |
| 282 | |
| 283 | /* does the dev_t match */ |
| 284 | if (is_blockdev(dev)) { |
| 285 | if (!S_ISBLK(stat->mode)) |
| 286 | return 0; |
| 287 | } else { |
| 288 | if (!S_ISCHR(stat->mode)) |
| 289 | return 0; |
| 290 | } |
| 291 | if (stat->rdev != dev->devt) |
| 292 | return 0; |
| 293 | |
| 294 | /* ours */ |
| 295 | return 1; |
| 296 | } |
| 297 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 298 | static int handle_remove(const char *nodename, struct device *dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 299 | { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 300 | struct path parent; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 301 | struct dentry *dentry; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 302 | int deleted = 1; |
| 303 | int err; |
| 304 | |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 305 | dentry = kern_path_locked(nodename, &parent); |
| 306 | if (IS_ERR(dentry)) |
| 307 | return PTR_ERR(dentry); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 308 | |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 309 | if (dentry->d_inode) { |
| 310 | struct kstat stat; |
Al Viro | 3dadecc | 2013-01-24 02:18:08 -0500 | [diff] [blame] | 311 | struct path p = {.mnt = parent.mnt, .dentry = dentry}; |
| 312 | err = vfs_getattr(&p, &stat); |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 313 | if (!err && dev_mynode(dev, dentry->d_inode, &stat)) { |
| 314 | struct iattr newattrs; |
| 315 | /* |
| 316 | * before unlinking this node, reset permissions |
| 317 | * of possible references like hardlinks |
| 318 | */ |
Eric W. Biederman | 91fa2cc | 2012-04-25 04:25:35 -0700 | [diff] [blame] | 319 | newattrs.ia_uid = GLOBAL_ROOT_UID; |
| 320 | newattrs.ia_gid = GLOBAL_ROOT_GID; |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 321 | newattrs.ia_mode = stat.mode & ~0777; |
| 322 | newattrs.ia_valid = |
| 323 | ATTR_UID|ATTR_GID|ATTR_MODE; |
| 324 | mutex_lock(&dentry->d_inode->i_mutex); |
| 325 | notify_change(dentry, &newattrs); |
| 326 | mutex_unlock(&dentry->d_inode->i_mutex); |
J. Bruce Fields | b21996e | 2011-09-20 09:14:34 -0400 | [diff] [blame] | 327 | err = vfs_unlink(parent.dentry->d_inode, dentry, NULL); |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 328 | if (!err || err == -ENOENT) |
| 329 | deleted = 1; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 330 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 331 | } else { |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 332 | err = -ENOENT; |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 333 | } |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 334 | dput(dentry); |
| 335 | mutex_unlock(&parent.dentry->d_inode->i_mutex); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 336 | |
Al Viro | 79714f7 | 2012-06-15 03:01:42 +0400 | [diff] [blame] | 337 | path_put(&parent); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 338 | if (deleted && strchr(nodename, '/')) |
| 339 | delete_path(nodename); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 340 | return err; |
| 341 | } |
| 342 | |
| 343 | /* |
| 344 | * If configured, or requested by the commandline, devtmpfs will be |
| 345 | * auto-mounted after the kernel mounted the root filesystem. |
| 346 | */ |
Kay Sievers | 073120c | 2009-10-28 19:51:17 +0100 | [diff] [blame] | 347 | int devtmpfs_mount(const char *mntdir) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 348 | { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 349 | int err; |
| 350 | |
Al Viro | fc14f2f | 2010-07-25 01:48:30 +0400 | [diff] [blame] | 351 | if (!mount_dev) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 352 | return 0; |
| 353 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 354 | if (!thread) |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 355 | return 0; |
| 356 | |
Kay Sievers | 073120c | 2009-10-28 19:51:17 +0100 | [diff] [blame] | 357 | err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 358 | if (err) |
| 359 | printk(KERN_INFO "devtmpfs: error mounting %i\n", err); |
| 360 | else |
| 361 | printk(KERN_INFO "devtmpfs: mounted\n"); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 362 | return err; |
| 363 | } |
| 364 | |
Arnaud Lacombe | f9e0b15 | 2011-07-21 13:16:19 -0400 | [diff] [blame] | 365 | static DECLARE_COMPLETION(setup_done); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 366 | |
Greg Kroah-Hartman | 4e4098a | 2013-04-11 11:43:29 -0700 | [diff] [blame] | 367 | static int handle(const char *name, umode_t mode, kuid_t uid, kgid_t gid, |
Kay Sievers | 3c2670e | 2013-04-06 09:56:00 -0700 | [diff] [blame] | 368 | struct device *dev) |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 369 | { |
| 370 | if (mode) |
Kay Sievers | 3c2670e | 2013-04-06 09:56:00 -0700 | [diff] [blame] | 371 | return handle_create(name, mode, uid, gid, dev); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 372 | else |
| 373 | return handle_remove(name, dev); |
| 374 | } |
| 375 | |
| 376 | static int devtmpfsd(void *p) |
| 377 | { |
| 378 | char options[] = "mode=0755"; |
| 379 | int *err = p; |
| 380 | *err = sys_unshare(CLONE_NEWNS); |
| 381 | if (*err) |
| 382 | goto out; |
| 383 | *err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options); |
| 384 | if (*err) |
| 385 | goto out; |
| 386 | sys_chdir("/.."); /* will traverse into overmounted root */ |
| 387 | sys_chroot("."); |
| 388 | complete(&setup_done); |
| 389 | while (1) { |
| 390 | spin_lock(&req_lock); |
| 391 | while (requests) { |
| 392 | struct req *req = requests; |
| 393 | requests = NULL; |
| 394 | spin_unlock(&req_lock); |
| 395 | while (req) { |
Al Viro | e13889b | 2011-07-25 14:15:50 -0400 | [diff] [blame] | 396 | struct req *next = req->next; |
Kay Sievers | 3c2670e | 2013-04-06 09:56:00 -0700 | [diff] [blame] | 397 | req->err = handle(req->name, req->mode, |
| 398 | req->uid, req->gid, req->dev); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 399 | complete(&req->done); |
Al Viro | e13889b | 2011-07-25 14:15:50 -0400 | [diff] [blame] | 400 | req = next; |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 401 | } |
| 402 | spin_lock(&req_lock); |
| 403 | } |
Kautuk Consul | 65e6757 | 2011-11-15 14:52:34 -0800 | [diff] [blame] | 404 | __set_current_state(TASK_INTERRUPTIBLE); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 405 | spin_unlock(&req_lock); |
| 406 | schedule(); |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 407 | } |
| 408 | return 0; |
| 409 | out: |
| 410 | complete(&setup_done); |
| 411 | return *err; |
| 412 | } |
| 413 | |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 414 | /* |
| 415 | * Create devtmpfs instance, driver-core devices will add their device |
| 416 | * nodes here. |
| 417 | */ |
| 418 | int __init devtmpfs_init(void) |
| 419 | { |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 420 | int err = register_filesystem(&dev_fs_type); |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 421 | if (err) { |
| 422 | printk(KERN_ERR "devtmpfs: unable to register devtmpfs " |
| 423 | "type %i\n", err); |
| 424 | return err; |
| 425 | } |
| 426 | |
Al Viro | 2780f1f | 2011-06-27 16:25:29 -0400 | [diff] [blame] | 427 | thread = kthread_run(devtmpfsd, &err, "kdevtmpfs"); |
| 428 | if (!IS_ERR(thread)) { |
| 429 | wait_for_completion(&setup_done); |
| 430 | } else { |
| 431 | err = PTR_ERR(thread); |
| 432 | thread = NULL; |
| 433 | } |
| 434 | |
| 435 | if (err) { |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 436 | printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err); |
| 437 | unregister_filesystem(&dev_fs_type); |
| 438 | return err; |
| 439 | } |
Kay Sievers | 2b2af54 | 2009-04-30 15:23:42 +0200 | [diff] [blame] | 440 | |
| 441 | printk(KERN_INFO "devtmpfs: initialized\n"); |
| 442 | return 0; |
| 443 | } |