Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/namei.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * Some corrections by tytso. |
| 9 | */ |
| 10 | |
| 11 | /* [Feb 1997 T. Schoebel-Theuer] Complete rewrite of the pathname |
| 12 | * lookup logic. |
| 13 | */ |
| 14 | /* [Feb-Apr 2000, AV] Rewrite to the new namespace architecture. |
| 15 | */ |
| 16 | |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/fs.h> |
| 21 | #include <linux/namei.h> |
| 22 | #include <linux/quotaops.h> |
| 23 | #include <linux/pagemap.h> |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 24 | #include <linux/fsnotify.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/personality.h> |
| 26 | #include <linux/security.h> |
Mimi Zohar | 6146f0d | 2009-02-04 09:06:57 -0500 | [diff] [blame] | 27 | #include <linux/ima.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | #include <linux/syscalls.h> |
| 29 | #include <linux/mount.h> |
| 30 | #include <linux/audit.h> |
Randy Dunlap | 16f7e0f | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 31 | #include <linux/capability.h> |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 32 | #include <linux/file.h> |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 33 | #include <linux/fcntl.h> |
Serge E. Hallyn | 08ce5f1 | 2008-04-29 01:00:10 -0700 | [diff] [blame] | 34 | #include <linux/device_cgroup.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <asm/uaccess.h> |
| 36 | |
| 37 | #define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE]) |
| 38 | |
| 39 | /* [Feb-1997 T. Schoebel-Theuer] |
| 40 | * Fundamental changes in the pathname lookup mechanisms (namei) |
| 41 | * were necessary because of omirr. The reason is that omirr needs |
| 42 | * to know the _real_ pathname, not the user-supplied one, in case |
| 43 | * of symlinks (and also when transname replacements occur). |
| 44 | * |
| 45 | * The new code replaces the old recursive symlink resolution with |
| 46 | * an iterative one (in case of non-nested symlink chains). It does |
| 47 | * this with calls to <fs>_follow_link(). |
| 48 | * As a side effect, dir_namei(), _namei() and follow_link() are now |
| 49 | * replaced with a single function lookup_dentry() that can handle all |
| 50 | * the special cases of the former code. |
| 51 | * |
| 52 | * With the new dcache, the pathname is stored at each inode, at least as |
| 53 | * long as the refcount of the inode is positive. As a side effect, the |
| 54 | * size of the dcache depends on the inode cache and thus is dynamic. |
| 55 | * |
| 56 | * [29-Apr-1998 C. Scott Ananian] Updated above description of symlink |
| 57 | * resolution to correspond with current state of the code. |
| 58 | * |
| 59 | * Note that the symlink resolution is not *completely* iterative. |
| 60 | * There is still a significant amount of tail- and mid- recursion in |
| 61 | * the algorithm. Also, note that <fs>_readlink() is not used in |
| 62 | * lookup_dentry(): lookup_dentry() on the result of <fs>_readlink() |
| 63 | * may return different results than <fs>_follow_link(). Many virtual |
| 64 | * filesystems (including /proc) exhibit this behavior. |
| 65 | */ |
| 66 | |
| 67 | /* [24-Feb-97 T. Schoebel-Theuer] Side effects caused by new implementation: |
| 68 | * New symlink semantics: when open() is called with flags O_CREAT | O_EXCL |
| 69 | * and the name already exists in form of a symlink, try to create the new |
| 70 | * name indicated by the symlink. The old code always complained that the |
| 71 | * name already exists, due to not following the symlink even if its target |
| 72 | * is nonexistent. The new semantics affects also mknod() and link() when |
| 73 | * the name is a symlink pointing to a non-existant name. |
| 74 | * |
| 75 | * I don't know which semantics is the right one, since I have no access |
| 76 | * to standards. But I found by trial that HP-UX 9.0 has the full "new" |
| 77 | * semantics implemented, while SunOS 4.1.1 and Solaris (SunOS 5.4) have the |
| 78 | * "old" one. Personally, I think the new semantics is much more logical. |
| 79 | * Note that "ln old new" where "new" is a symlink pointing to a non-existing |
| 80 | * file does succeed in both HP-UX and SunOs, but not in Solaris |
| 81 | * and in the old Linux semantics. |
| 82 | */ |
| 83 | |
| 84 | /* [16-Dec-97 Kevin Buhr] For security reasons, we change some symlink |
| 85 | * semantics. See the comments in "open_namei" and "do_link" below. |
| 86 | * |
| 87 | * [10-Sep-98 Alan Modra] Another symlink change. |
| 88 | */ |
| 89 | |
| 90 | /* [Feb-Apr 2000 AV] Complete rewrite. Rules for symlinks: |
| 91 | * inside the path - always follow. |
| 92 | * in the last component in creation/removal/renaming - never follow. |
| 93 | * if LOOKUP_FOLLOW passed - follow. |
| 94 | * if the pathname has trailing slashes - follow. |
| 95 | * otherwise - don't follow. |
| 96 | * (applied in that order). |
| 97 | * |
| 98 | * [Jun 2000 AV] Inconsistent behaviour of open() in case if flags==O_CREAT |
| 99 | * restored for 2.4. This is the last surviving part of old 4.2BSD bug. |
| 100 | * During the 2.4 we need to fix the userland stuff depending on it - |
| 101 | * hopefully we will be able to get rid of that wart in 2.5. So far only |
| 102 | * XEmacs seems to be relying on it... |
| 103 | */ |
| 104 | /* |
| 105 | * [Sep 2001 AV] Single-semaphore locking scheme (kudos to David Holland) |
Arjan van de Ven | a11f3a0 | 2006-03-23 03:00:33 -0800 | [diff] [blame] | 106 | * implemented. Let's see if raised priority of ->s_vfs_rename_mutex gives |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | * any extra contention... |
| 108 | */ |
| 109 | |
Al Viro | a02f76c | 2008-02-23 15:14:28 +0000 | [diff] [blame] | 110 | static int __link_path_walk(const char *name, struct nameidata *nd); |
Josef 'Jeff' Sipek | c4a7808 | 2007-07-19 01:48:22 -0700 | [diff] [blame] | 111 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | /* In order to reduce some races, while at the same time doing additional |
| 113 | * checking and hopefully speeding things up, we copy filenames to the |
| 114 | * kernel data space before using them.. |
| 115 | * |
| 116 | * POSIX.1 2.4: an empty pathname is invalid (ENOENT). |
| 117 | * PATH_MAX includes the nul terminator --RR. |
| 118 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 119 | static int do_getname(const char __user *filename, char *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | { |
| 121 | int retval; |
| 122 | unsigned long len = PATH_MAX; |
| 123 | |
| 124 | if (!segment_eq(get_fs(), KERNEL_DS)) { |
| 125 | if ((unsigned long) filename >= TASK_SIZE) |
| 126 | return -EFAULT; |
| 127 | if (TASK_SIZE - (unsigned long) filename < PATH_MAX) |
| 128 | len = TASK_SIZE - (unsigned long) filename; |
| 129 | } |
| 130 | |
| 131 | retval = strncpy_from_user(page, filename, len); |
| 132 | if (retval > 0) { |
| 133 | if (retval < len) |
| 134 | return 0; |
| 135 | return -ENAMETOOLONG; |
| 136 | } else if (!retval) |
| 137 | retval = -ENOENT; |
| 138 | return retval; |
| 139 | } |
| 140 | |
| 141 | char * getname(const char __user * filename) |
| 142 | { |
| 143 | char *tmp, *result; |
| 144 | |
| 145 | result = ERR_PTR(-ENOMEM); |
| 146 | tmp = __getname(); |
| 147 | if (tmp) { |
| 148 | int retval = do_getname(filename, tmp); |
| 149 | |
| 150 | result = tmp; |
| 151 | if (retval < 0) { |
| 152 | __putname(tmp); |
| 153 | result = ERR_PTR(retval); |
| 154 | } |
| 155 | } |
| 156 | audit_getname(result); |
| 157 | return result; |
| 158 | } |
| 159 | |
| 160 | #ifdef CONFIG_AUDITSYSCALL |
| 161 | void putname(const char *name) |
| 162 | { |
Al Viro | 5ac3a9c | 2006-07-16 06:38:45 -0400 | [diff] [blame] | 163 | if (unlikely(!audit_dummy_context())) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | audit_putname(name); |
| 165 | else |
| 166 | __putname(name); |
| 167 | } |
| 168 | EXPORT_SYMBOL(putname); |
| 169 | #endif |
| 170 | |
| 171 | |
| 172 | /** |
| 173 | * generic_permission - check for access rights on a Posix-like filesystem |
| 174 | * @inode: inode to check access rights for |
| 175 | * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) |
| 176 | * @check_acl: optional callback to check for Posix ACLs |
| 177 | * |
| 178 | * Used to check for read/write/execute permissions on a file. |
| 179 | * We use "fsuid" for this, letting us set arbitrary permissions |
| 180 | * for filesystem access without changing the "normal" uids which |
| 181 | * are used for other things.. |
| 182 | */ |
| 183 | int generic_permission(struct inode *inode, int mask, |
| 184 | int (*check_acl)(struct inode *inode, int mask)) |
| 185 | { |
| 186 | umode_t mode = inode->i_mode; |
| 187 | |
Al Viro | e6305c4 | 2008-07-15 21:03:57 -0400 | [diff] [blame] | 188 | mask &= MAY_READ | MAY_WRITE | MAY_EXEC; |
| 189 | |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 190 | if (current_fsuid() == inode->i_uid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | mode >>= 6; |
| 192 | else { |
| 193 | if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) { |
| 194 | int error = check_acl(inode, mask); |
| 195 | if (error == -EACCES) |
| 196 | goto check_capabilities; |
| 197 | else if (error != -EAGAIN) |
| 198 | return error; |
| 199 | } |
| 200 | |
| 201 | if (in_group_p(inode->i_gid)) |
| 202 | mode >>= 3; |
| 203 | } |
| 204 | |
| 205 | /* |
| 206 | * If the DACs are ok we don't need any capability check. |
| 207 | */ |
Al Viro | e6305c4 | 2008-07-15 21:03:57 -0400 | [diff] [blame] | 208 | if ((mask & ~mode) == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | return 0; |
| 210 | |
| 211 | check_capabilities: |
| 212 | /* |
| 213 | * Read/write DACs are always overridable. |
| 214 | * Executable DACs are overridable if at least one exec bit is set. |
| 215 | */ |
Miklos Szeredi | f696a36 | 2008-07-31 13:41:58 +0200 | [diff] [blame] | 216 | if (!(mask & MAY_EXEC) || execute_ok(inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | if (capable(CAP_DAC_OVERRIDE)) |
| 218 | return 0; |
| 219 | |
| 220 | /* |
| 221 | * Searching includes executable on directories, else just read. |
| 222 | */ |
| 223 | if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE))) |
| 224 | if (capable(CAP_DAC_READ_SEARCH)) |
| 225 | return 0; |
| 226 | |
| 227 | return -EACCES; |
| 228 | } |
| 229 | |
Christoph Hellwig | cb23beb | 2008-10-24 09:59:29 +0200 | [diff] [blame] | 230 | /** |
| 231 | * inode_permission - check for access rights to a given inode |
| 232 | * @inode: inode to check permission on |
| 233 | * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) |
| 234 | * |
| 235 | * Used to check for read/write/execute permissions on an inode. |
| 236 | * We use "fsuid" for this, letting us set arbitrary permissions |
| 237 | * for filesystem access without changing the "normal" uids which |
| 238 | * are used for other things. |
| 239 | */ |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 240 | int inode_permission(struct inode *inode, int mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | { |
Al Viro | e6305c4 | 2008-07-15 21:03:57 -0400 | [diff] [blame] | 242 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | |
| 244 | if (mask & MAY_WRITE) { |
Miklos Szeredi | 22590e4 | 2007-10-16 23:27:08 -0700 | [diff] [blame] | 245 | umode_t mode = inode->i_mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | |
| 247 | /* |
| 248 | * Nobody gets write access to a read-only fs. |
| 249 | */ |
| 250 | if (IS_RDONLY(inode) && |
| 251 | (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) |
| 252 | return -EROFS; |
| 253 | |
| 254 | /* |
| 255 | * Nobody gets write access to an immutable file. |
| 256 | */ |
| 257 | if (IS_IMMUTABLE(inode)) |
| 258 | return -EACCES; |
| 259 | } |
| 260 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 261 | if (inode->i_op->permission) |
Al Viro | b77b064 | 2008-07-17 09:37:02 -0400 | [diff] [blame] | 262 | retval = inode->i_op->permission(inode, mask); |
Miklos Szeredi | f696a36 | 2008-07-31 13:41:58 +0200 | [diff] [blame] | 263 | else |
Al Viro | e6305c4 | 2008-07-15 21:03:57 -0400 | [diff] [blame] | 264 | retval = generic_permission(inode, mask, NULL); |
Miklos Szeredi | f696a36 | 2008-07-31 13:41:58 +0200 | [diff] [blame] | 265 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | if (retval) |
| 267 | return retval; |
| 268 | |
Serge E. Hallyn | 08ce5f1 | 2008-04-29 01:00:10 -0700 | [diff] [blame] | 269 | retval = devcgroup_inode_permission(inode, mask); |
| 270 | if (retval) |
| 271 | return retval; |
| 272 | |
Al Viro | e6305c4 | 2008-07-15 21:03:57 -0400 | [diff] [blame] | 273 | return security_inode_permission(inode, |
Stephen Smalley | f418b00 | 2008-07-28 13:32:38 -0400 | [diff] [blame] | 274 | mask & (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | } |
| 276 | |
Christoph Hellwig | e4543ed | 2005-11-08 21:35:04 -0800 | [diff] [blame] | 277 | /** |
Christoph Hellwig | 8c744fb | 2005-11-08 21:35:04 -0800 | [diff] [blame] | 278 | * file_permission - check for additional access rights to a given file |
| 279 | * @file: file to check access rights for |
| 280 | * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) |
| 281 | * |
| 282 | * Used to check for read/write/execute permissions on an already opened |
| 283 | * file. |
| 284 | * |
| 285 | * Note: |
| 286 | * Do not use this function in new code. All access checks should |
Christoph Hellwig | cb23beb | 2008-10-24 09:59:29 +0200 | [diff] [blame] | 287 | * be done using inode_permission(). |
Christoph Hellwig | 8c744fb | 2005-11-08 21:35:04 -0800 | [diff] [blame] | 288 | */ |
| 289 | int file_permission(struct file *file, int mask) |
| 290 | { |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 291 | return inode_permission(file->f_path.dentry->d_inode, mask); |
Christoph Hellwig | 8c744fb | 2005-11-08 21:35:04 -0800 | [diff] [blame] | 292 | } |
| 293 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | /* |
| 295 | * get_write_access() gets write permission for a file. |
| 296 | * put_write_access() releases this write permission. |
| 297 | * This is used for regular files. |
| 298 | * We cannot support write (and maybe mmap read-write shared) accesses and |
| 299 | * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode |
| 300 | * can have the following values: |
| 301 | * 0: no writers, no VM_DENYWRITE mappings |
| 302 | * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist |
| 303 | * > 0: (i_writecount) users are writing to the file. |
| 304 | * |
| 305 | * Normally we operate on that counter with atomic_{inc,dec} and it's safe |
| 306 | * except for the cases where we don't hold i_writecount yet. Then we need to |
| 307 | * use {get,deny}_write_access() - these functions check the sign and refuse |
| 308 | * to do the change if sign is wrong. Exclusion between them is provided by |
| 309 | * the inode->i_lock spinlock. |
| 310 | */ |
| 311 | |
| 312 | int get_write_access(struct inode * inode) |
| 313 | { |
| 314 | spin_lock(&inode->i_lock); |
| 315 | if (atomic_read(&inode->i_writecount) < 0) { |
| 316 | spin_unlock(&inode->i_lock); |
| 317 | return -ETXTBSY; |
| 318 | } |
| 319 | atomic_inc(&inode->i_writecount); |
| 320 | spin_unlock(&inode->i_lock); |
| 321 | |
| 322 | return 0; |
| 323 | } |
| 324 | |
| 325 | int deny_write_access(struct file * file) |
| 326 | { |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 327 | struct inode *inode = file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | |
| 329 | spin_lock(&inode->i_lock); |
| 330 | if (atomic_read(&inode->i_writecount) > 0) { |
| 331 | spin_unlock(&inode->i_lock); |
| 332 | return -ETXTBSY; |
| 333 | } |
| 334 | atomic_dec(&inode->i_writecount); |
| 335 | spin_unlock(&inode->i_lock); |
| 336 | |
| 337 | return 0; |
| 338 | } |
| 339 | |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 340 | /** |
Jan Blunck | 5dd784d0 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 341 | * path_get - get a reference to a path |
| 342 | * @path: path to get the reference to |
| 343 | * |
| 344 | * Given a path increment the reference count to the dentry and the vfsmount. |
| 345 | */ |
| 346 | void path_get(struct path *path) |
| 347 | { |
| 348 | mntget(path->mnt); |
| 349 | dget(path->dentry); |
| 350 | } |
| 351 | EXPORT_SYMBOL(path_get); |
| 352 | |
| 353 | /** |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 354 | * path_put - put a reference to a path |
| 355 | * @path: path to put the reference to |
| 356 | * |
| 357 | * Given a path decrement the reference count to the dentry and the vfsmount. |
| 358 | */ |
| 359 | void path_put(struct path *path) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | { |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 361 | dput(path->dentry); |
| 362 | mntput(path->mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | } |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 364 | EXPORT_SYMBOL(path_put); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 366 | /** |
| 367 | * release_open_intent - free up open intent resources |
| 368 | * @nd: pointer to nameidata |
| 369 | */ |
| 370 | void release_open_intent(struct nameidata *nd) |
| 371 | { |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 372 | if (nd->intent.open.file->f_path.dentry == NULL) |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 373 | put_filp(nd->intent.open.file); |
| 374 | else |
| 375 | fput(nd->intent.open.file); |
| 376 | } |
| 377 | |
Ian Kent | bcdc5e0 | 2006-09-27 01:50:44 -0700 | [diff] [blame] | 378 | static inline struct dentry * |
| 379 | do_revalidate(struct dentry *dentry, struct nameidata *nd) |
| 380 | { |
| 381 | int status = dentry->d_op->d_revalidate(dentry, nd); |
| 382 | if (unlikely(status <= 0)) { |
| 383 | /* |
| 384 | * The dentry failed validation. |
| 385 | * If d_revalidate returned 0 attempt to invalidate |
| 386 | * the dentry otherwise d_revalidate is asking us |
| 387 | * to return a fail status. |
| 388 | */ |
| 389 | if (!status) { |
| 390 | if (!d_invalidate(dentry)) { |
| 391 | dput(dentry); |
| 392 | dentry = NULL; |
| 393 | } |
| 394 | } else { |
| 395 | dput(dentry); |
| 396 | dentry = ERR_PTR(status); |
| 397 | } |
| 398 | } |
| 399 | return dentry; |
| 400 | } |
| 401 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | /* |
| 403 | * Internal lookup() using the new generic dcache. |
| 404 | * SMP-safe |
| 405 | */ |
| 406 | static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd) |
| 407 | { |
| 408 | struct dentry * dentry = __d_lookup(parent, name); |
| 409 | |
| 410 | /* lockess __d_lookup may fail due to concurrent d_move() |
| 411 | * in some unrelated directory, so try with d_lookup |
| 412 | */ |
| 413 | if (!dentry) |
| 414 | dentry = d_lookup(parent, name); |
| 415 | |
Ian Kent | bcdc5e0 | 2006-09-27 01:50:44 -0700 | [diff] [blame] | 416 | if (dentry && dentry->d_op && dentry->d_op->d_revalidate) |
| 417 | dentry = do_revalidate(dentry, nd); |
| 418 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | return dentry; |
| 420 | } |
| 421 | |
| 422 | /* |
| 423 | * Short-cut version of permission(), for calling by |
| 424 | * path_walk(), when dcache lock is held. Combines parts |
| 425 | * of permission() and generic_permission(), and tests ONLY for |
| 426 | * MAY_EXEC permission. |
| 427 | * |
| 428 | * If appropriate, check DAC only. If not appropriate, or |
| 429 | * short-cut DAC fails, then call permission() to do more |
| 430 | * complete permission check. |
| 431 | */ |
Al Viro | 672b16b | 2008-07-17 09:45:01 -0400 | [diff] [blame] | 432 | static int exec_permission_lite(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | { |
| 434 | umode_t mode = inode->i_mode; |
| 435 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 436 | if (inode->i_op->permission) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | return -EAGAIN; |
| 438 | |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 439 | if (current_fsuid() == inode->i_uid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | mode >>= 6; |
| 441 | else if (in_group_p(inode->i_gid)) |
| 442 | mode >>= 3; |
| 443 | |
| 444 | if (mode & MAY_EXEC) |
| 445 | goto ok; |
| 446 | |
| 447 | if ((inode->i_mode & S_IXUGO) && capable(CAP_DAC_OVERRIDE)) |
| 448 | goto ok; |
| 449 | |
| 450 | if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_OVERRIDE)) |
| 451 | goto ok; |
| 452 | |
| 453 | if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_READ_SEARCH)) |
| 454 | goto ok; |
| 455 | |
| 456 | return -EACCES; |
| 457 | ok: |
Al Viro | b77b064 | 2008-07-17 09:37:02 -0400 | [diff] [blame] | 458 | return security_inode_permission(inode, MAY_EXEC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | } |
| 460 | |
| 461 | /* |
| 462 | * This is called when everything else fails, and we actually have |
| 463 | * to go to the low-level filesystem to find out what we should do.. |
| 464 | * |
| 465 | * We get the directory semaphore, and after getting that we also |
| 466 | * make sure that nobody added the entry to the dcache in the meantime.. |
| 467 | * SMP-safe |
| 468 | */ |
| 469 | static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd) |
| 470 | { |
| 471 | struct dentry * result; |
| 472 | struct inode *dir = parent->d_inode; |
| 473 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 474 | mutex_lock(&dir->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | /* |
| 476 | * First re-do the cached lookup just in case it was created |
| 477 | * while we waited for the directory semaphore.. |
| 478 | * |
| 479 | * FIXME! This could use version numbering or similar to |
| 480 | * avoid unnecessary cache lookups. |
| 481 | * |
| 482 | * The "dcache_lock" is purely to protect the RCU list walker |
| 483 | * from concurrent renames at this point (we mustn't get false |
| 484 | * negatives from the RCU list walk here, unlike the optimistic |
| 485 | * fast walk). |
| 486 | * |
| 487 | * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup |
| 488 | */ |
| 489 | result = d_lookup(parent, name); |
| 490 | if (!result) { |
Miklos Szeredi | d70b67c | 2008-07-02 21:30:15 +0200 | [diff] [blame] | 491 | struct dentry *dentry; |
| 492 | |
| 493 | /* Don't create child dentry for a dead directory. */ |
| 494 | result = ERR_PTR(-ENOENT); |
| 495 | if (IS_DEADDIR(dir)) |
| 496 | goto out_unlock; |
| 497 | |
| 498 | dentry = d_alloc(parent, name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | result = ERR_PTR(-ENOMEM); |
| 500 | if (dentry) { |
| 501 | result = dir->i_op->lookup(dir, dentry, nd); |
| 502 | if (result) |
| 503 | dput(dentry); |
| 504 | else |
| 505 | result = dentry; |
| 506 | } |
Miklos Szeredi | d70b67c | 2008-07-02 21:30:15 +0200 | [diff] [blame] | 507 | out_unlock: |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 508 | mutex_unlock(&dir->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | return result; |
| 510 | } |
| 511 | |
| 512 | /* |
| 513 | * Uhhuh! Nasty case: the cache was re-populated while |
| 514 | * we waited on the semaphore. Need to revalidate. |
| 515 | */ |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 516 | mutex_unlock(&dir->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | if (result->d_op && result->d_op->d_revalidate) { |
Ian Kent | bcdc5e0 | 2006-09-27 01:50:44 -0700 | [diff] [blame] | 518 | result = do_revalidate(result, nd); |
| 519 | if (!result) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | result = ERR_PTR(-ENOENT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | } |
| 522 | return result; |
| 523 | } |
| 524 | |
Al Viro | a02f76c | 2008-02-23 15:14:28 +0000 | [diff] [blame] | 525 | /* |
| 526 | * Wrapper to retry pathname resolution whenever the underlying |
| 527 | * file system returns an ESTALE. |
| 528 | * |
| 529 | * Retry the whole path once, forcing real lookup requests |
| 530 | * instead of relying on the dcache. |
| 531 | */ |
| 532 | static __always_inline int link_path_walk(const char *name, struct nameidata *nd) |
| 533 | { |
| 534 | struct path save = nd->path; |
| 535 | int result; |
| 536 | |
| 537 | /* make sure the stuff we saved doesn't go away */ |
Jan Blunck | c8e7f44 | 2008-06-09 16:40:35 -0700 | [diff] [blame] | 538 | path_get(&save); |
Al Viro | a02f76c | 2008-02-23 15:14:28 +0000 | [diff] [blame] | 539 | |
| 540 | result = __link_path_walk(name, nd); |
| 541 | if (result == -ESTALE) { |
| 542 | /* nd->path had been dropped */ |
| 543 | nd->path = save; |
Jan Blunck | c8e7f44 | 2008-06-09 16:40:35 -0700 | [diff] [blame] | 544 | path_get(&nd->path); |
Al Viro | a02f76c | 2008-02-23 15:14:28 +0000 | [diff] [blame] | 545 | nd->flags |= LOOKUP_REVAL; |
| 546 | result = __link_path_walk(name, nd); |
| 547 | } |
| 548 | |
| 549 | path_put(&save); |
| 550 | |
| 551 | return result; |
| 552 | } |
| 553 | |
Arjan van de Ven | f166235 | 2006-01-14 13:21:31 -0800 | [diff] [blame] | 554 | static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | { |
| 556 | int res = 0; |
| 557 | char *name; |
| 558 | if (IS_ERR(link)) |
| 559 | goto fail; |
| 560 | |
| 561 | if (*link == '/') { |
Christoph Hellwig | b4091d5 | 2008-11-05 15:07:21 +0100 | [diff] [blame] | 562 | struct fs_struct *fs = current->fs; |
| 563 | |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 564 | path_put(&nd->path); |
Christoph Hellwig | b4091d5 | 2008-11-05 15:07:21 +0100 | [diff] [blame] | 565 | |
| 566 | read_lock(&fs->lock); |
| 567 | nd->path = fs->root; |
| 568 | path_get(&fs->root); |
| 569 | read_unlock(&fs->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | } |
Christoph Hellwig | b4091d5 | 2008-11-05 15:07:21 +0100 | [diff] [blame] | 571 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | res = link_path_walk(link, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | if (nd->depth || res || nd->last_type!=LAST_NORM) |
| 574 | return res; |
| 575 | /* |
| 576 | * If it is an iterative symlinks resolution in open_namei() we |
| 577 | * have to copy the last component. And all that crap because of |
| 578 | * bloody create() on broken symlinks. Furrfu... |
| 579 | */ |
| 580 | name = __getname(); |
| 581 | if (unlikely(!name)) { |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 582 | path_put(&nd->path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | return -ENOMEM; |
| 584 | } |
| 585 | strcpy(name, nd->last.name); |
| 586 | nd->last.name = name; |
| 587 | return 0; |
| 588 | fail: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 589 | path_put(&nd->path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | return PTR_ERR(link); |
| 591 | } |
| 592 | |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 593 | static void path_put_conditional(struct path *path, struct nameidata *nd) |
Miklos Szeredi | 09dd17d | 2005-09-06 15:18:21 -0700 | [diff] [blame] | 594 | { |
| 595 | dput(path->dentry); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 596 | if (path->mnt != nd->path.mnt) |
Miklos Szeredi | 09dd17d | 2005-09-06 15:18:21 -0700 | [diff] [blame] | 597 | mntput(path->mnt); |
| 598 | } |
| 599 | |
| 600 | static inline void path_to_nameidata(struct path *path, struct nameidata *nd) |
| 601 | { |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 602 | dput(nd->path.dentry); |
| 603 | if (nd->path.mnt != path->mnt) |
| 604 | mntput(nd->path.mnt); |
| 605 | nd->path.mnt = path->mnt; |
| 606 | nd->path.dentry = path->dentry; |
Miklos Szeredi | 09dd17d | 2005-09-06 15:18:21 -0700 | [diff] [blame] | 607 | } |
| 608 | |
Ian Kent | 051d381 | 2006-03-27 01:14:53 -0800 | [diff] [blame] | 609 | static __always_inline int __do_follow_link(struct path *path, struct nameidata *nd) |
| 610 | { |
| 611 | int error; |
| 612 | void *cookie; |
| 613 | struct dentry *dentry = path->dentry; |
| 614 | |
| 615 | touch_atime(path->mnt, dentry); |
| 616 | nd_set_link(nd, NULL); |
| 617 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 618 | if (path->mnt != nd->path.mnt) { |
Ian Kent | 051d381 | 2006-03-27 01:14:53 -0800 | [diff] [blame] | 619 | path_to_nameidata(path, nd); |
| 620 | dget(dentry); |
| 621 | } |
| 622 | mntget(path->mnt); |
| 623 | cookie = dentry->d_inode->i_op->follow_link(dentry, nd); |
| 624 | error = PTR_ERR(cookie); |
| 625 | if (!IS_ERR(cookie)) { |
| 626 | char *s = nd_get_link(nd); |
| 627 | error = 0; |
| 628 | if (s) |
| 629 | error = __vfs_follow_link(nd, s); |
| 630 | if (dentry->d_inode->i_op->put_link) |
| 631 | dentry->d_inode->i_op->put_link(dentry, nd, cookie); |
| 632 | } |
Jan Blunck | 09da5916 | 2008-02-14 19:34:37 -0800 | [diff] [blame] | 633 | path_put(path); |
Ian Kent | 051d381 | 2006-03-27 01:14:53 -0800 | [diff] [blame] | 634 | |
| 635 | return error; |
| 636 | } |
| 637 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | /* |
| 639 | * This limits recursive symlink follows to 8, while |
| 640 | * limiting consecutive symlinks to 40. |
| 641 | * |
| 642 | * Without that kind of total limit, nasty chains of consecutive |
| 643 | * symlinks can cause almost arbitrarily long lookups. |
| 644 | */ |
Al Viro | 90ebe56 | 2005-06-06 13:35:58 -0700 | [diff] [blame] | 645 | static inline int do_follow_link(struct path *path, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | { |
| 647 | int err = -ELOOP; |
| 648 | if (current->link_count >= MAX_NESTED_LINKS) |
| 649 | goto loop; |
| 650 | if (current->total_link_count >= 40) |
| 651 | goto loop; |
| 652 | BUG_ON(nd->depth >= MAX_NESTED_LINKS); |
| 653 | cond_resched(); |
Al Viro | 90ebe56 | 2005-06-06 13:35:58 -0700 | [diff] [blame] | 654 | err = security_inode_follow_link(path->dentry, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | if (err) |
| 656 | goto loop; |
| 657 | current->link_count++; |
| 658 | current->total_link_count++; |
| 659 | nd->depth++; |
Al Viro | cd4e91d | 2005-06-06 13:36:03 -0700 | [diff] [blame] | 660 | err = __do_follow_link(path, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | current->link_count--; |
| 662 | nd->depth--; |
| 663 | return err; |
| 664 | loop: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 665 | path_put_conditional(path, nd); |
| 666 | path_put(&nd->path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | return err; |
| 668 | } |
| 669 | |
| 670 | int follow_up(struct vfsmount **mnt, struct dentry **dentry) |
| 671 | { |
| 672 | struct vfsmount *parent; |
| 673 | struct dentry *mountpoint; |
| 674 | spin_lock(&vfsmount_lock); |
| 675 | parent=(*mnt)->mnt_parent; |
| 676 | if (parent == *mnt) { |
| 677 | spin_unlock(&vfsmount_lock); |
| 678 | return 0; |
| 679 | } |
| 680 | mntget(parent); |
| 681 | mountpoint=dget((*mnt)->mnt_mountpoint); |
| 682 | spin_unlock(&vfsmount_lock); |
| 683 | dput(*dentry); |
| 684 | *dentry = mountpoint; |
| 685 | mntput(*mnt); |
| 686 | *mnt = parent; |
| 687 | return 1; |
| 688 | } |
| 689 | |
| 690 | /* no need for dcache_lock, as serialization is taken care in |
| 691 | * namespace.c |
| 692 | */ |
Al Viro | 463ffb2 | 2005-06-06 13:36:05 -0700 | [diff] [blame] | 693 | static int __follow_mount(struct path *path) |
| 694 | { |
| 695 | int res = 0; |
| 696 | while (d_mountpoint(path->dentry)) { |
| 697 | struct vfsmount *mounted = lookup_mnt(path->mnt, path->dentry); |
| 698 | if (!mounted) |
| 699 | break; |
| 700 | dput(path->dentry); |
| 701 | if (res) |
| 702 | mntput(path->mnt); |
| 703 | path->mnt = mounted; |
| 704 | path->dentry = dget(mounted->mnt_root); |
| 705 | res = 1; |
| 706 | } |
| 707 | return res; |
| 708 | } |
| 709 | |
Al Viro | 58c465e | 2005-06-06 13:36:13 -0700 | [diff] [blame] | 710 | static void follow_mount(struct vfsmount **mnt, struct dentry **dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 711 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | while (d_mountpoint(*dentry)) { |
| 713 | struct vfsmount *mounted = lookup_mnt(*mnt, *dentry); |
| 714 | if (!mounted) |
| 715 | break; |
Al Viro | 58c465e | 2005-06-06 13:36:13 -0700 | [diff] [blame] | 716 | dput(*dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | mntput(*mnt); |
| 718 | *mnt = mounted; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 719 | *dentry = dget(mounted->mnt_root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 720 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | } |
| 722 | |
| 723 | /* no need for dcache_lock, as serialization is taken care in |
| 724 | * namespace.c |
| 725 | */ |
Al Viro | e13b210 | 2005-06-06 13:36:06 -0700 | [diff] [blame] | 726 | int follow_down(struct vfsmount **mnt, struct dentry **dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | { |
| 728 | struct vfsmount *mounted; |
| 729 | |
| 730 | mounted = lookup_mnt(*mnt, *dentry); |
| 731 | if (mounted) { |
Al Viro | e13b210 | 2005-06-06 13:36:06 -0700 | [diff] [blame] | 732 | dput(*dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | mntput(*mnt); |
| 734 | *mnt = mounted; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | *dentry = dget(mounted->mnt_root); |
| 736 | return 1; |
| 737 | } |
| 738 | return 0; |
| 739 | } |
| 740 | |
Arjan van de Ven | f166235 | 2006-01-14 13:21:31 -0800 | [diff] [blame] | 741 | static __always_inline void follow_dotdot(struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | { |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 743 | struct fs_struct *fs = current->fs; |
| 744 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | while(1) { |
| 746 | struct vfsmount *parent; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 747 | struct dentry *old = nd->path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 749 | read_lock(&fs->lock); |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 750 | if (nd->path.dentry == fs->root.dentry && |
| 751 | nd->path.mnt == fs->root.mnt) { |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 752 | read_unlock(&fs->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | break; |
| 754 | } |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 755 | read_unlock(&fs->lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | spin_lock(&dcache_lock); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 757 | if (nd->path.dentry != nd->path.mnt->mnt_root) { |
| 758 | nd->path.dentry = dget(nd->path.dentry->d_parent); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | spin_unlock(&dcache_lock); |
| 760 | dput(old); |
| 761 | break; |
| 762 | } |
| 763 | spin_unlock(&dcache_lock); |
| 764 | spin_lock(&vfsmount_lock); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 765 | parent = nd->path.mnt->mnt_parent; |
| 766 | if (parent == nd->path.mnt) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | spin_unlock(&vfsmount_lock); |
| 768 | break; |
| 769 | } |
| 770 | mntget(parent); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 771 | nd->path.dentry = dget(nd->path.mnt->mnt_mountpoint); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | spin_unlock(&vfsmount_lock); |
| 773 | dput(old); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 774 | mntput(nd->path.mnt); |
| 775 | nd->path.mnt = parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | } |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 777 | follow_mount(&nd->path.mnt, &nd->path.dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | } |
| 779 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | /* |
| 781 | * It's more convoluted than I'd like it to be, but... it's still fairly |
| 782 | * small and for now I'd prefer to have fast path as straight as possible. |
| 783 | * It _is_ time-critical. |
| 784 | */ |
| 785 | static int do_lookup(struct nameidata *nd, struct qstr *name, |
| 786 | struct path *path) |
| 787 | { |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 788 | struct vfsmount *mnt = nd->path.mnt; |
| 789 | struct dentry *dentry = __d_lookup(nd->path.dentry, name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | |
| 791 | if (!dentry) |
| 792 | goto need_lookup; |
| 793 | if (dentry->d_op && dentry->d_op->d_revalidate) |
| 794 | goto need_revalidate; |
| 795 | done: |
| 796 | path->mnt = mnt; |
| 797 | path->dentry = dentry; |
Al Viro | 634ee70 | 2005-06-06 13:36:13 -0700 | [diff] [blame] | 798 | __follow_mount(path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | return 0; |
| 800 | |
| 801 | need_lookup: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 802 | dentry = real_lookup(nd->path.dentry, name, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | if (IS_ERR(dentry)) |
| 804 | goto fail; |
| 805 | goto done; |
| 806 | |
| 807 | need_revalidate: |
Ian Kent | bcdc5e0 | 2006-09-27 01:50:44 -0700 | [diff] [blame] | 808 | dentry = do_revalidate(dentry, nd); |
| 809 | if (!dentry) |
| 810 | goto need_lookup; |
| 811 | if (IS_ERR(dentry)) |
| 812 | goto fail; |
| 813 | goto done; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | |
| 815 | fail: |
| 816 | return PTR_ERR(dentry); |
| 817 | } |
| 818 | |
| 819 | /* |
| 820 | * Name resolution. |
Prasanna Meda | ea3834d | 2005-04-29 16:00:17 +0100 | [diff] [blame] | 821 | * This is the basic name resolution function, turning a pathname into |
| 822 | * the final dentry. We expect 'base' to be positive and a directory. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 823 | * |
Prasanna Meda | ea3834d | 2005-04-29 16:00:17 +0100 | [diff] [blame] | 824 | * Returns 0 and nd will have valid dentry and mnt on success. |
| 825 | * Returns error and drops reference to input namei data on failure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | */ |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 827 | static int __link_path_walk(const char *name, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 828 | { |
| 829 | struct path next; |
| 830 | struct inode *inode; |
| 831 | int err; |
| 832 | unsigned int lookup_flags = nd->flags; |
| 833 | |
| 834 | while (*name=='/') |
| 835 | name++; |
| 836 | if (!*name) |
| 837 | goto return_reval; |
| 838 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 839 | inode = nd->path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | if (nd->depth) |
Trond Myklebust | f55eab8 | 2006-02-04 23:28:01 -0800 | [diff] [blame] | 841 | lookup_flags = LOOKUP_FOLLOW | (nd->flags & LOOKUP_CONTINUE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | |
| 843 | /* At this point we know we have a real path component. */ |
| 844 | for(;;) { |
| 845 | unsigned long hash; |
| 846 | struct qstr this; |
| 847 | unsigned int c; |
| 848 | |
Trond Myklebust | cdce5d6 | 2005-10-18 14:20:18 -0700 | [diff] [blame] | 849 | nd->flags |= LOOKUP_CONTINUE; |
Al Viro | 672b16b | 2008-07-17 09:45:01 -0400 | [diff] [blame] | 850 | err = exec_permission_lite(inode); |
Christoph Hellwig | e4543ed | 2005-11-08 21:35:04 -0800 | [diff] [blame] | 851 | if (err == -EAGAIN) |
Christoph Hellwig | cb23beb | 2008-10-24 09:59:29 +0200 | [diff] [blame] | 852 | err = inode_permission(nd->path.dentry->d_inode, |
| 853 | MAY_EXEC); |
Mimi Zohar | 6146f0d | 2009-02-04 09:06:57 -0500 | [diff] [blame] | 854 | if (!err) |
| 855 | err = ima_path_check(&nd->path, MAY_EXEC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | if (err) |
| 857 | break; |
| 858 | |
| 859 | this.name = name; |
| 860 | c = *(const unsigned char *)name; |
| 861 | |
| 862 | hash = init_name_hash(); |
| 863 | do { |
| 864 | name++; |
| 865 | hash = partial_name_hash(c, hash); |
| 866 | c = *(const unsigned char *)name; |
| 867 | } while (c && (c != '/')); |
| 868 | this.len = name - (const char *) this.name; |
| 869 | this.hash = end_name_hash(hash); |
| 870 | |
| 871 | /* remove trailing slashes? */ |
| 872 | if (!c) |
| 873 | goto last_component; |
| 874 | while (*++name == '/'); |
| 875 | if (!*name) |
| 876 | goto last_with_slashes; |
| 877 | |
| 878 | /* |
| 879 | * "." and ".." are special - ".." especially so because it has |
| 880 | * to be able to know about the current root directory and |
| 881 | * parent relationships. |
| 882 | */ |
| 883 | if (this.name[0] == '.') switch (this.len) { |
| 884 | default: |
| 885 | break; |
| 886 | case 2: |
| 887 | if (this.name[1] != '.') |
| 888 | break; |
Al Viro | 58c465e | 2005-06-06 13:36:13 -0700 | [diff] [blame] | 889 | follow_dotdot(nd); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 890 | inode = nd->path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | /* fallthrough */ |
| 892 | case 1: |
| 893 | continue; |
| 894 | } |
| 895 | /* |
| 896 | * See if the low-level filesystem might want |
| 897 | * to use its own hash.. |
| 898 | */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 899 | if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) { |
| 900 | err = nd->path.dentry->d_op->d_hash(nd->path.dentry, |
| 901 | &this); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 902 | if (err < 0) |
| 903 | break; |
| 904 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 905 | /* This does the actual lookups.. */ |
| 906 | err = do_lookup(nd, &this, &next); |
| 907 | if (err) |
| 908 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 909 | |
| 910 | err = -ENOENT; |
| 911 | inode = next.dentry->d_inode; |
| 912 | if (!inode) |
| 913 | goto out_dput; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 914 | |
| 915 | if (inode->i_op->follow_link) { |
Al Viro | 90ebe56 | 2005-06-06 13:35:58 -0700 | [diff] [blame] | 916 | err = do_follow_link(&next, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 917 | if (err) |
| 918 | goto return_err; |
| 919 | err = -ENOENT; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 920 | inode = nd->path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 921 | if (!inode) |
| 922 | break; |
Miklos Szeredi | 09dd17d | 2005-09-06 15:18:21 -0700 | [diff] [blame] | 923 | } else |
| 924 | path_to_nameidata(&next, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 925 | err = -ENOTDIR; |
| 926 | if (!inode->i_op->lookup) |
| 927 | break; |
| 928 | continue; |
| 929 | /* here ends the main loop */ |
| 930 | |
| 931 | last_with_slashes: |
| 932 | lookup_flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
| 933 | last_component: |
Trond Myklebust | f55eab8 | 2006-02-04 23:28:01 -0800 | [diff] [blame] | 934 | /* Clear LOOKUP_CONTINUE iff it was previously unset */ |
| 935 | nd->flags &= lookup_flags | ~LOOKUP_CONTINUE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 936 | if (lookup_flags & LOOKUP_PARENT) |
| 937 | goto lookup_parent; |
| 938 | if (this.name[0] == '.') switch (this.len) { |
| 939 | default: |
| 940 | break; |
| 941 | case 2: |
| 942 | if (this.name[1] != '.') |
| 943 | break; |
Al Viro | 58c465e | 2005-06-06 13:36:13 -0700 | [diff] [blame] | 944 | follow_dotdot(nd); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 945 | inode = nd->path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 946 | /* fallthrough */ |
| 947 | case 1: |
| 948 | goto return_reval; |
| 949 | } |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 950 | if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) { |
| 951 | err = nd->path.dentry->d_op->d_hash(nd->path.dentry, |
| 952 | &this); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 953 | if (err < 0) |
| 954 | break; |
| 955 | } |
| 956 | err = do_lookup(nd, &this, &next); |
| 957 | if (err) |
| 958 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 959 | inode = next.dentry->d_inode; |
| 960 | if ((lookup_flags & LOOKUP_FOLLOW) |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 961 | && inode && inode->i_op->follow_link) { |
Al Viro | 90ebe56 | 2005-06-06 13:35:58 -0700 | [diff] [blame] | 962 | err = do_follow_link(&next, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | if (err) |
| 964 | goto return_err; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 965 | inode = nd->path.dentry->d_inode; |
Miklos Szeredi | 09dd17d | 2005-09-06 15:18:21 -0700 | [diff] [blame] | 966 | } else |
| 967 | path_to_nameidata(&next, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | err = -ENOENT; |
| 969 | if (!inode) |
| 970 | break; |
| 971 | if (lookup_flags & LOOKUP_DIRECTORY) { |
| 972 | err = -ENOTDIR; |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 973 | if (!inode->i_op->lookup) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | break; |
| 975 | } |
| 976 | goto return_base; |
| 977 | lookup_parent: |
| 978 | nd->last = this; |
| 979 | nd->last_type = LAST_NORM; |
| 980 | if (this.name[0] != '.') |
| 981 | goto return_base; |
| 982 | if (this.len == 1) |
| 983 | nd->last_type = LAST_DOT; |
| 984 | else if (this.len == 2 && this.name[1] == '.') |
| 985 | nd->last_type = LAST_DOTDOT; |
| 986 | else |
| 987 | goto return_base; |
| 988 | return_reval: |
| 989 | /* |
| 990 | * We bypassed the ordinary revalidation routines. |
| 991 | * We may need to check the cached dentry for staleness. |
| 992 | */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 993 | if (nd->path.dentry && nd->path.dentry->d_sb && |
| 994 | (nd->path.dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 995 | err = -ESTALE; |
| 996 | /* Note: we do not d_invalidate() */ |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 997 | if (!nd->path.dentry->d_op->d_revalidate( |
| 998 | nd->path.dentry, nd)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 999 | break; |
| 1000 | } |
| 1001 | return_base: |
| 1002 | return 0; |
| 1003 | out_dput: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1004 | path_put_conditional(&next, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1005 | break; |
| 1006 | } |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 1007 | path_put(&nd->path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | return_err: |
| 1009 | return err; |
| 1010 | } |
| 1011 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 1012 | static int path_walk(const char *name, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1013 | { |
| 1014 | current->total_link_count = 0; |
| 1015 | return link_path_walk(name, nd); |
| 1016 | } |
| 1017 | |
Prasanna Meda | ea3834d | 2005-04-29 16:00:17 +0100 | [diff] [blame] | 1018 | /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 1019 | static int do_path_lookup(int dfd, const char *name, |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1020 | unsigned int flags, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1021 | { |
Prasanna Meda | ea3834d | 2005-04-29 16:00:17 +0100 | [diff] [blame] | 1022 | int retval = 0; |
Ulrich Drepper | 170aa3d | 2006-02-04 23:28:02 -0800 | [diff] [blame] | 1023 | int fput_needed; |
| 1024 | struct file *file; |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 1025 | struct fs_struct *fs = current->fs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1026 | |
| 1027 | nd->last_type = LAST_ROOT; /* if there are only slashes... */ |
| 1028 | nd->flags = flags; |
| 1029 | nd->depth = 0; |
| 1030 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1031 | if (*name=='/') { |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 1032 | read_lock(&fs->lock); |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1033 | nd->path = fs->root; |
| 1034 | path_get(&fs->root); |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 1035 | read_unlock(&fs->lock); |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1036 | } else if (dfd == AT_FDCWD) { |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 1037 | read_lock(&fs->lock); |
Jan Blunck | 6ac08c3 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1038 | nd->path = fs->pwd; |
| 1039 | path_get(&fs->pwd); |
Andreas Mohr | e518ddb | 2006-09-29 02:01:22 -0700 | [diff] [blame] | 1040 | read_unlock(&fs->lock); |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1041 | } else { |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1042 | struct dentry *dentry; |
| 1043 | |
| 1044 | file = fget_light(dfd, &fput_needed); |
Ulrich Drepper | 170aa3d | 2006-02-04 23:28:02 -0800 | [diff] [blame] | 1045 | retval = -EBADF; |
| 1046 | if (!file) |
Trond Myklebust | 6d09bb6 | 2006-06-04 02:51:37 -0700 | [diff] [blame] | 1047 | goto out_fail; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1048 | |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 1049 | dentry = file->f_path.dentry; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1050 | |
Ulrich Drepper | 170aa3d | 2006-02-04 23:28:02 -0800 | [diff] [blame] | 1051 | retval = -ENOTDIR; |
| 1052 | if (!S_ISDIR(dentry->d_inode->i_mode)) |
Trond Myklebust | 6d09bb6 | 2006-06-04 02:51:37 -0700 | [diff] [blame] | 1053 | goto fput_fail; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1054 | |
| 1055 | retval = file_permission(file, MAY_EXEC); |
Ulrich Drepper | 170aa3d | 2006-02-04 23:28:02 -0800 | [diff] [blame] | 1056 | if (retval) |
Trond Myklebust | 6d09bb6 | 2006-06-04 02:51:37 -0700 | [diff] [blame] | 1057 | goto fput_fail; |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1058 | |
Jan Blunck | 5dd784d0 | 2008-02-14 19:34:38 -0800 | [diff] [blame] | 1059 | nd->path = file->f_path; |
| 1060 | path_get(&file->f_path); |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1061 | |
| 1062 | fput_light(file, fput_needed); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1063 | } |
Josef 'Jeff' Sipek | 2dfdd26 | 2007-05-09 02:33:41 -0700 | [diff] [blame] | 1064 | |
| 1065 | retval = path_walk(name, nd); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1066 | if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && |
| 1067 | nd->path.dentry->d_inode)) |
| 1068 | audit_inode(name, nd->path.dentry); |
Trond Myklebust | 6d09bb6 | 2006-06-04 02:51:37 -0700 | [diff] [blame] | 1069 | out_fail: |
Ulrich Drepper | 170aa3d | 2006-02-04 23:28:02 -0800 | [diff] [blame] | 1070 | return retval; |
| 1071 | |
Trond Myklebust | 6d09bb6 | 2006-06-04 02:51:37 -0700 | [diff] [blame] | 1072 | fput_fail: |
Ulrich Drepper | 170aa3d | 2006-02-04 23:28:02 -0800 | [diff] [blame] | 1073 | fput_light(file, fput_needed); |
Trond Myklebust | 6d09bb6 | 2006-06-04 02:51:37 -0700 | [diff] [blame] | 1074 | goto out_fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1075 | } |
| 1076 | |
Harvey Harrison | fc9b52c | 2008-02-08 04:19:52 -0800 | [diff] [blame] | 1077 | int path_lookup(const char *name, unsigned int flags, |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1078 | struct nameidata *nd) |
| 1079 | { |
| 1080 | return do_path_lookup(AT_FDCWD, name, flags, nd); |
| 1081 | } |
| 1082 | |
Al Viro | d181146 | 2008-08-02 00:49:18 -0400 | [diff] [blame] | 1083 | int kern_path(const char *name, unsigned int flags, struct path *path) |
| 1084 | { |
| 1085 | struct nameidata nd; |
| 1086 | int res = do_path_lookup(AT_FDCWD, name, flags, &nd); |
| 1087 | if (!res) |
| 1088 | *path = nd.path; |
| 1089 | return res; |
| 1090 | } |
| 1091 | |
Josef 'Jeff' Sipek | 16f1820 | 2007-07-19 01:48:18 -0700 | [diff] [blame] | 1092 | /** |
| 1093 | * vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair |
| 1094 | * @dentry: pointer to dentry of the base directory |
| 1095 | * @mnt: pointer to vfs mount of the base directory |
| 1096 | * @name: pointer to file name |
| 1097 | * @flags: lookup flags |
| 1098 | * @nd: pointer to nameidata |
| 1099 | */ |
| 1100 | int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, |
| 1101 | const char *name, unsigned int flags, |
| 1102 | struct nameidata *nd) |
| 1103 | { |
| 1104 | int retval; |
| 1105 | |
| 1106 | /* same as do_path_lookup */ |
| 1107 | nd->last_type = LAST_ROOT; |
| 1108 | nd->flags = flags; |
| 1109 | nd->depth = 0; |
| 1110 | |
Jan Blunck | c8e7f44 | 2008-06-09 16:40:35 -0700 | [diff] [blame] | 1111 | nd->path.dentry = dentry; |
| 1112 | nd->path.mnt = mnt; |
| 1113 | path_get(&nd->path); |
Josef 'Jeff' Sipek | 16f1820 | 2007-07-19 01:48:18 -0700 | [diff] [blame] | 1114 | |
| 1115 | retval = path_walk(name, nd); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1116 | if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && |
| 1117 | nd->path.dentry->d_inode)) |
| 1118 | audit_inode(name, nd->path.dentry); |
Josef 'Jeff' Sipek | 16f1820 | 2007-07-19 01:48:18 -0700 | [diff] [blame] | 1119 | |
| 1120 | return retval; |
| 1121 | |
| 1122 | } |
| 1123 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 1124 | /** |
| 1125 | * path_lookup_open - lookup a file path with open intent |
Martin Waitz | 7045f37 | 2006-02-01 03:06:57 -0800 | [diff] [blame] | 1126 | * @dfd: the directory to use as base, or AT_FDCWD |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 1127 | * @name: pointer to file name |
| 1128 | * @lookup_flags: lookup intent flags |
| 1129 | * @nd: pointer to nameidata |
| 1130 | * @open_flags: open intent flags |
| 1131 | */ |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1132 | int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags, |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 1133 | struct nameidata *nd, int open_flags) |
| 1134 | { |
Al Viro | 8737f3a | 2008-08-02 22:36:57 -0400 | [diff] [blame] | 1135 | struct file *filp = get_empty_filp(); |
| 1136 | int err; |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 1137 | |
Al Viro | 8737f3a | 2008-08-02 22:36:57 -0400 | [diff] [blame] | 1138 | if (filp == NULL) |
| 1139 | return -ENFILE; |
| 1140 | nd->intent.open.file = filp; |
| 1141 | nd->intent.open.flags = open_flags; |
| 1142 | nd->intent.open.create_mode = 0; |
| 1143 | err = do_path_lookup(dfd, name, lookup_flags|LOOKUP_OPEN, nd); |
| 1144 | if (IS_ERR(nd->intent.open.file)) { |
| 1145 | if (err == 0) { |
| 1146 | err = PTR_ERR(nd->intent.open.file); |
| 1147 | path_put(&nd->path); |
| 1148 | } |
| 1149 | } else if (err != 0) |
| 1150 | release_open_intent(nd); |
| 1151 | return err; |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 1152 | } |
| 1153 | |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1154 | static struct dentry *__lookup_hash(struct qstr *name, |
| 1155 | struct dentry *base, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1156 | { |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1157 | struct dentry *dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | struct inode *inode; |
| 1159 | int err; |
| 1160 | |
| 1161 | inode = base->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | |
| 1163 | /* |
| 1164 | * See if the low-level filesystem might want |
| 1165 | * to use its own hash.. |
| 1166 | */ |
| 1167 | if (base->d_op && base->d_op->d_hash) { |
| 1168 | err = base->d_op->d_hash(base, name); |
| 1169 | dentry = ERR_PTR(err); |
| 1170 | if (err < 0) |
| 1171 | goto out; |
| 1172 | } |
| 1173 | |
| 1174 | dentry = cached_lookup(base, name, nd); |
| 1175 | if (!dentry) { |
Miklos Szeredi | d70b67c | 2008-07-02 21:30:15 +0200 | [diff] [blame] | 1176 | struct dentry *new; |
| 1177 | |
| 1178 | /* Don't create child dentry for a dead directory. */ |
| 1179 | dentry = ERR_PTR(-ENOENT); |
| 1180 | if (IS_DEADDIR(inode)) |
| 1181 | goto out; |
| 1182 | |
| 1183 | new = d_alloc(base, name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1184 | dentry = ERR_PTR(-ENOMEM); |
| 1185 | if (!new) |
| 1186 | goto out; |
| 1187 | dentry = inode->i_op->lookup(inode, new, nd); |
| 1188 | if (!dentry) |
| 1189 | dentry = new; |
| 1190 | else |
| 1191 | dput(new); |
| 1192 | } |
| 1193 | out: |
| 1194 | return dentry; |
| 1195 | } |
| 1196 | |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1197 | /* |
| 1198 | * Restricted form of lookup. Doesn't follow links, single-component only, |
| 1199 | * needs parent already locked. Doesn't follow mounts. |
| 1200 | * SMP-safe. |
| 1201 | */ |
Adrian Bunk | a244e16 | 2006-03-31 02:32:11 -0800 | [diff] [blame] | 1202 | static struct dentry *lookup_hash(struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1203 | { |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1204 | int err; |
| 1205 | |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 1206 | err = inode_permission(nd->path.dentry->d_inode, MAY_EXEC); |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1207 | if (err) |
| 1208 | return ERR_PTR(err); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1209 | return __lookup_hash(&nd->last, nd->path.dentry, nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1210 | } |
| 1211 | |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1212 | static int __lookup_one_len(const char *name, struct qstr *this, |
| 1213 | struct dentry *base, int len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1214 | { |
| 1215 | unsigned long hash; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1216 | unsigned int c; |
| 1217 | |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1218 | this->name = name; |
| 1219 | this->len = len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1220 | if (!len) |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1221 | return -EACCES; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1222 | |
| 1223 | hash = init_name_hash(); |
| 1224 | while (len--) { |
| 1225 | c = *(const unsigned char *)name++; |
| 1226 | if (c == '/' || c == '\0') |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1227 | return -EACCES; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | hash = partial_name_hash(c, hash); |
| 1229 | } |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1230 | this->hash = end_name_hash(hash); |
| 1231 | return 0; |
| 1232 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1233 | |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1234 | /** |
Randy Dunlap | a6b9191 | 2008-03-19 17:01:00 -0700 | [diff] [blame] | 1235 | * lookup_one_len - filesystem helper to lookup single pathname component |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1236 | * @name: pathname component to lookup |
| 1237 | * @base: base directory to lookup from |
| 1238 | * @len: maximum length @len should be interpreted to |
| 1239 | * |
Randy Dunlap | a6b9191 | 2008-03-19 17:01:00 -0700 | [diff] [blame] | 1240 | * Note that this routine is purely a helper for filesystem usage and should |
| 1241 | * not be called by generic code. Also note that by using this function the |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1242 | * nameidata argument is passed to the filesystem methods and a filesystem |
| 1243 | * using this helper needs to be prepared for that. |
| 1244 | */ |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1245 | struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) |
| 1246 | { |
| 1247 | int err; |
| 1248 | struct qstr this; |
| 1249 | |
| 1250 | err = __lookup_one_len(name, &this, base, len); |
| 1251 | if (err) |
| 1252 | return ERR_PTR(err); |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1253 | |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 1254 | err = inode_permission(base->d_inode, MAY_EXEC); |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1255 | if (err) |
| 1256 | return ERR_PTR(err); |
Christoph Hellwig | 49705b7 | 2005-11-08 21:35:06 -0800 | [diff] [blame] | 1257 | return __lookup_hash(&this, base, NULL); |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1258 | } |
| 1259 | |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1260 | /** |
| 1261 | * lookup_one_noperm - bad hack for sysfs |
| 1262 | * @name: pathname component to lookup |
| 1263 | * @base: base directory to lookup from |
| 1264 | * |
| 1265 | * This is a variant of lookup_one_len that doesn't perform any permission |
| 1266 | * checks. It's a horrible hack to work around the braindead sysfs |
| 1267 | * architecture and should not be used anywhere else. |
| 1268 | * |
| 1269 | * DON'T USE THIS FUNCTION EVER, thanks. |
| 1270 | */ |
| 1271 | struct dentry *lookup_one_noperm(const char *name, struct dentry *base) |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1272 | { |
| 1273 | int err; |
| 1274 | struct qstr this; |
| 1275 | |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1276 | err = __lookup_one_len(name, &this, base, strlen(name)); |
James Morris | 057f6c0 | 2007-04-26 00:12:05 -0700 | [diff] [blame] | 1277 | if (err) |
| 1278 | return ERR_PTR(err); |
Christoph Hellwig | eead191 | 2007-10-16 23:25:38 -0700 | [diff] [blame] | 1279 | return __lookup_hash(&this, base, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1280 | } |
| 1281 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 1282 | int user_path_at(int dfd, const char __user *name, unsigned flags, |
| 1283 | struct path *path) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1284 | { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 1285 | struct nameidata nd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | char *tmp = getname(name); |
| 1287 | int err = PTR_ERR(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1288 | if (!IS_ERR(tmp)) { |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 1289 | |
| 1290 | BUG_ON(flags & LOOKUP_PARENT); |
| 1291 | |
| 1292 | err = do_path_lookup(dfd, tmp, flags, &nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1293 | putname(tmp); |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 1294 | if (!err) |
| 1295 | *path = nd.path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1296 | } |
| 1297 | return err; |
| 1298 | } |
| 1299 | |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 1300 | static int user_path_parent(int dfd, const char __user *path, |
| 1301 | struct nameidata *nd, char **name) |
| 1302 | { |
| 1303 | char *s = getname(path); |
| 1304 | int error; |
| 1305 | |
| 1306 | if (IS_ERR(s)) |
| 1307 | return PTR_ERR(s); |
| 1308 | |
| 1309 | error = do_path_lookup(dfd, s, LOOKUP_PARENT, nd); |
| 1310 | if (error) |
| 1311 | putname(s); |
| 1312 | else |
| 1313 | *name = s; |
| 1314 | |
| 1315 | return error; |
| 1316 | } |
| 1317 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1318 | /* |
| 1319 | * It's inline, so penalty for filesystems that don't use sticky bit is |
| 1320 | * minimal. |
| 1321 | */ |
| 1322 | static inline int check_sticky(struct inode *dir, struct inode *inode) |
| 1323 | { |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 1324 | uid_t fsuid = current_fsuid(); |
| 1325 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1326 | if (!(dir->i_mode & S_ISVTX)) |
| 1327 | return 0; |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 1328 | if (inode->i_uid == fsuid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | return 0; |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 1330 | if (dir->i_uid == fsuid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1331 | return 0; |
| 1332 | return !capable(CAP_FOWNER); |
| 1333 | } |
| 1334 | |
| 1335 | /* |
| 1336 | * Check whether we can remove a link victim from directory dir, check |
| 1337 | * whether the type of victim is right. |
| 1338 | * 1. We can't do it if dir is read-only (done in permission()) |
| 1339 | * 2. We should have write and exec permissions on dir |
| 1340 | * 3. We can't remove anything from append-only dir |
| 1341 | * 4. We can't do anything with immutable dir (done in permission()) |
| 1342 | * 5. If the sticky bit on dir is set we should either |
| 1343 | * a. be owner of dir, or |
| 1344 | * b. be owner of victim, or |
| 1345 | * c. have CAP_FOWNER capability |
| 1346 | * 6. If the victim is append-only or immutable we can't do antyhing with |
| 1347 | * links pointing to it. |
| 1348 | * 7. If we were asked to remove a directory and victim isn't one - ENOTDIR. |
| 1349 | * 8. If we were asked to remove a non-directory and victim isn't one - EISDIR. |
| 1350 | * 9. We can't remove a root or mountpoint. |
| 1351 | * 10. We don't allow removal of NFS sillyrenamed files; it's handled by |
| 1352 | * nfs_async_unlink(). |
| 1353 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 1354 | static int may_delete(struct inode *dir,struct dentry *victim,int isdir) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1355 | { |
| 1356 | int error; |
| 1357 | |
| 1358 | if (!victim->d_inode) |
| 1359 | return -ENOENT; |
| 1360 | |
| 1361 | BUG_ON(victim->d_parent->d_inode != dir); |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 1362 | audit_inode_child(victim->d_name.name, victim, dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1363 | |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 1364 | error = inode_permission(dir, MAY_WRITE | MAY_EXEC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1365 | if (error) |
| 1366 | return error; |
| 1367 | if (IS_APPEND(dir)) |
| 1368 | return -EPERM; |
| 1369 | if (check_sticky(dir, victim->d_inode)||IS_APPEND(victim->d_inode)|| |
Hugh Dickins | f945454 | 2008-11-19 15:36:38 -0800 | [diff] [blame] | 1370 | IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1371 | return -EPERM; |
| 1372 | if (isdir) { |
| 1373 | if (!S_ISDIR(victim->d_inode->i_mode)) |
| 1374 | return -ENOTDIR; |
| 1375 | if (IS_ROOT(victim)) |
| 1376 | return -EBUSY; |
| 1377 | } else if (S_ISDIR(victim->d_inode->i_mode)) |
| 1378 | return -EISDIR; |
| 1379 | if (IS_DEADDIR(dir)) |
| 1380 | return -ENOENT; |
| 1381 | if (victim->d_flags & DCACHE_NFSFS_RENAMED) |
| 1382 | return -EBUSY; |
| 1383 | return 0; |
| 1384 | } |
| 1385 | |
| 1386 | /* Check whether we can create an object with dentry child in directory |
| 1387 | * dir. |
| 1388 | * 1. We can't do it if child already exists (open has special treatment for |
| 1389 | * this case, but since we are inlined it's OK) |
| 1390 | * 2. We can't do it if dir is read-only (done in permission()) |
| 1391 | * 3. We should have write and exec permissions on dir |
| 1392 | * 4. We can't do it if dir is immutable (done in permission()) |
| 1393 | */ |
Miklos Szeredi | a95164d | 2008-07-30 15:08:48 +0200 | [diff] [blame] | 1394 | static inline int may_create(struct inode *dir, struct dentry *child) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1395 | { |
| 1396 | if (child->d_inode) |
| 1397 | return -EEXIST; |
| 1398 | if (IS_DEADDIR(dir)) |
| 1399 | return -ENOENT; |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 1400 | return inode_permission(dir, MAY_WRITE | MAY_EXEC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1401 | } |
| 1402 | |
| 1403 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1404 | * O_DIRECTORY translates into forcing a directory lookup. |
| 1405 | */ |
| 1406 | static inline int lookup_flags(unsigned int f) |
| 1407 | { |
| 1408 | unsigned long retval = LOOKUP_FOLLOW; |
| 1409 | |
| 1410 | if (f & O_NOFOLLOW) |
| 1411 | retval &= ~LOOKUP_FOLLOW; |
| 1412 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1413 | if (f & O_DIRECTORY) |
| 1414 | retval |= LOOKUP_DIRECTORY; |
| 1415 | |
| 1416 | return retval; |
| 1417 | } |
| 1418 | |
| 1419 | /* |
| 1420 | * p1 and p2 should be directories on the same fs. |
| 1421 | */ |
| 1422 | struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) |
| 1423 | { |
| 1424 | struct dentry *p; |
| 1425 | |
| 1426 | if (p1 == p2) { |
Ingo Molnar | f2eace2 | 2006-07-03 00:25:05 -0700 | [diff] [blame] | 1427 | mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | return NULL; |
| 1429 | } |
| 1430 | |
Arjan van de Ven | a11f3a0 | 2006-03-23 03:00:33 -0800 | [diff] [blame] | 1431 | mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1432 | |
OGAWA Hirofumi | e2761a1 | 2008-10-16 07:50:28 +0900 | [diff] [blame] | 1433 | p = d_ancestor(p2, p1); |
| 1434 | if (p) { |
| 1435 | mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT); |
| 1436 | mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD); |
| 1437 | return p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | } |
| 1439 | |
OGAWA Hirofumi | e2761a1 | 2008-10-16 07:50:28 +0900 | [diff] [blame] | 1440 | p = d_ancestor(p1, p2); |
| 1441 | if (p) { |
| 1442 | mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); |
| 1443 | mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); |
| 1444 | return p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1445 | } |
| 1446 | |
Ingo Molnar | f2eace2 | 2006-07-03 00:25:05 -0700 | [diff] [blame] | 1447 | mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); |
| 1448 | mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | return NULL; |
| 1450 | } |
| 1451 | |
| 1452 | void unlock_rename(struct dentry *p1, struct dentry *p2) |
| 1453 | { |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1454 | mutex_unlock(&p1->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1455 | if (p1 != p2) { |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1456 | mutex_unlock(&p2->d_inode->i_mutex); |
Arjan van de Ven | a11f3a0 | 2006-03-23 03:00:33 -0800 | [diff] [blame] | 1457 | mutex_unlock(&p1->d_inode->i_sb->s_vfs_rename_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1458 | } |
| 1459 | } |
| 1460 | |
| 1461 | int vfs_create(struct inode *dir, struct dentry *dentry, int mode, |
| 1462 | struct nameidata *nd) |
| 1463 | { |
Miklos Szeredi | a95164d | 2008-07-30 15:08:48 +0200 | [diff] [blame] | 1464 | int error = may_create(dir, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | |
| 1466 | if (error) |
| 1467 | return error; |
| 1468 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 1469 | if (!dir->i_op->create) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | return -EACCES; /* shouldn't it be ENOSYS? */ |
| 1471 | mode &= S_IALLUGO; |
| 1472 | mode |= S_IFREG; |
| 1473 | error = security_inode_create(dir, dentry, mode); |
| 1474 | if (error) |
| 1475 | return error; |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 1476 | vfs_dq_init(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1477 | error = dir->i_op->create(dir, dentry, mode, nd); |
Stephen Smalley | a74574a | 2005-09-09 13:01:44 -0700 | [diff] [blame] | 1478 | if (!error) |
Amy Griffis | f38aa94 | 2005-11-03 15:57:06 +0000 | [diff] [blame] | 1479 | fsnotify_create(dir, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1480 | return error; |
| 1481 | } |
| 1482 | |
Christoph Hellwig | 3fb6419 | 2008-10-24 09:58:10 +0200 | [diff] [blame] | 1483 | int may_open(struct path *path, int acc_mode, int flag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1484 | { |
Christoph Hellwig | 3fb6419 | 2008-10-24 09:58:10 +0200 | [diff] [blame] | 1485 | struct dentry *dentry = path->dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1486 | struct inode *inode = dentry->d_inode; |
| 1487 | int error; |
| 1488 | |
| 1489 | if (!inode) |
| 1490 | return -ENOENT; |
| 1491 | |
Christoph Hellwig | c8fe8f3 | 2009-01-05 19:27:23 +0100 | [diff] [blame] | 1492 | switch (inode->i_mode & S_IFMT) { |
| 1493 | case S_IFLNK: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | return -ELOOP; |
Christoph Hellwig | c8fe8f3 | 2009-01-05 19:27:23 +0100 | [diff] [blame] | 1495 | case S_IFDIR: |
| 1496 | if (acc_mode & MAY_WRITE) |
| 1497 | return -EISDIR; |
| 1498 | break; |
| 1499 | case S_IFBLK: |
| 1500 | case S_IFCHR: |
Christoph Hellwig | 3fb6419 | 2008-10-24 09:58:10 +0200 | [diff] [blame] | 1501 | if (path->mnt->mnt_flags & MNT_NODEV) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1502 | return -EACCES; |
Christoph Hellwig | c8fe8f3 | 2009-01-05 19:27:23 +0100 | [diff] [blame] | 1503 | /*FALLTHRU*/ |
| 1504 | case S_IFIFO: |
| 1505 | case S_IFSOCK: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1506 | flag &= ~O_TRUNC; |
Christoph Hellwig | c8fe8f3 | 2009-01-05 19:27:23 +0100 | [diff] [blame] | 1507 | break; |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1508 | } |
Dave Hansen | b41572e | 2007-10-16 23:31:14 -0700 | [diff] [blame] | 1509 | |
Christoph Hellwig | 3fb6419 | 2008-10-24 09:58:10 +0200 | [diff] [blame] | 1510 | error = inode_permission(inode, acc_mode); |
Dave Hansen | b41572e | 2007-10-16 23:31:14 -0700 | [diff] [blame] | 1511 | if (error) |
| 1512 | return error; |
Mimi Zohar | 6146f0d | 2009-02-04 09:06:57 -0500 | [diff] [blame] | 1513 | |
James Morris | cb5629b | 2009-02-06 11:01:45 +1100 | [diff] [blame] | 1514 | error = ima_path_check(path, |
Mimi Zohar | 6146f0d | 2009-02-04 09:06:57 -0500 | [diff] [blame] | 1515 | acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC)); |
| 1516 | if (error) |
| 1517 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1518 | /* |
| 1519 | * An append-only file must be opened in append mode for writing. |
| 1520 | */ |
| 1521 | if (IS_APPEND(inode)) { |
| 1522 | if ((flag & FMODE_WRITE) && !(flag & O_APPEND)) |
| 1523 | return -EPERM; |
| 1524 | if (flag & O_TRUNC) |
| 1525 | return -EPERM; |
| 1526 | } |
| 1527 | |
| 1528 | /* O_NOATIME can only be set by the owner or superuser */ |
| 1529 | if (flag & O_NOATIME) |
Satyam Sharma | 3bd858a | 2007-07-17 15:00:08 +0530 | [diff] [blame] | 1530 | if (!is_owner_or_cap(inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1531 | return -EPERM; |
| 1532 | |
| 1533 | /* |
| 1534 | * Ensure there are no outstanding leases on the file. |
| 1535 | */ |
| 1536 | error = break_lease(inode, flag); |
| 1537 | if (error) |
| 1538 | return error; |
| 1539 | |
| 1540 | if (flag & O_TRUNC) { |
| 1541 | error = get_write_access(inode); |
| 1542 | if (error) |
| 1543 | return error; |
| 1544 | |
| 1545 | /* |
| 1546 | * Refuse to truncate files with mandatory locks held on them. |
| 1547 | */ |
| 1548 | error = locks_verify_locked(inode); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 1549 | if (!error) |
Christoph Hellwig | 3fb6419 | 2008-10-24 09:58:10 +0200 | [diff] [blame] | 1550 | error = security_path_truncate(path, 0, |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 1551 | ATTR_MTIME|ATTR_CTIME|ATTR_OPEN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1552 | if (!error) { |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 1553 | vfs_dq_init(inode); |
Miklos Szeredi | d139d7f | 2007-10-18 03:07:00 -0700 | [diff] [blame] | 1554 | |
| 1555 | error = do_truncate(dentry, 0, |
| 1556 | ATTR_MTIME|ATTR_CTIME|ATTR_OPEN, |
| 1557 | NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1558 | } |
| 1559 | put_write_access(inode); |
| 1560 | if (error) |
| 1561 | return error; |
| 1562 | } else |
| 1563 | if (flag & FMODE_WRITE) |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 1564 | vfs_dq_init(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1565 | |
| 1566 | return 0; |
| 1567 | } |
| 1568 | |
Dave Hansen | d57999e | 2008-02-15 14:37:27 -0800 | [diff] [blame] | 1569 | /* |
| 1570 | * Be careful about ever adding any more callers of this |
| 1571 | * function. Its flags must be in the namei format, not |
| 1572 | * what get passed to sys_open(). |
| 1573 | */ |
| 1574 | static int __open_namei_create(struct nameidata *nd, struct path *path, |
Dave Hansen | aab520e | 2006-09-30 23:29:02 -0700 | [diff] [blame] | 1575 | int flag, int mode) |
| 1576 | { |
| 1577 | int error; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1578 | struct dentry *dir = nd->path.dentry; |
Dave Hansen | aab520e | 2006-09-30 23:29:02 -0700 | [diff] [blame] | 1579 | |
| 1580 | if (!IS_POSIXACL(dir->d_inode)) |
| 1581 | mode &= ~current->fs->umask; |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 1582 | error = security_path_mknod(&nd->path, path->dentry, mode, 0); |
| 1583 | if (error) |
| 1584 | goto out_unlock; |
Dave Hansen | aab520e | 2006-09-30 23:29:02 -0700 | [diff] [blame] | 1585 | error = vfs_create(dir->d_inode, path->dentry, mode, nd); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 1586 | out_unlock: |
Dave Hansen | aab520e | 2006-09-30 23:29:02 -0700 | [diff] [blame] | 1587 | mutex_unlock(&dir->d_inode->i_mutex); |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1588 | dput(nd->path.dentry); |
| 1589 | nd->path.dentry = path->dentry; |
Dave Hansen | aab520e | 2006-09-30 23:29:02 -0700 | [diff] [blame] | 1590 | if (error) |
| 1591 | return error; |
| 1592 | /* Don't check for write permission, don't truncate */ |
Christoph Hellwig | 3fb6419 | 2008-10-24 09:58:10 +0200 | [diff] [blame] | 1593 | return may_open(&nd->path, 0, flag & ~O_TRUNC); |
Dave Hansen | aab520e | 2006-09-30 23:29:02 -0700 | [diff] [blame] | 1594 | } |
| 1595 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1596 | /* |
Dave Hansen | d57999e | 2008-02-15 14:37:27 -0800 | [diff] [blame] | 1597 | * Note that while the flag value (low two bits) for sys_open means: |
| 1598 | * 00 - read-only |
| 1599 | * 01 - write-only |
| 1600 | * 10 - read-write |
| 1601 | * 11 - special |
| 1602 | * it is changed into |
| 1603 | * 00 - no permissions needed |
| 1604 | * 01 - read-permission |
| 1605 | * 10 - write-permission |
| 1606 | * 11 - read-write |
| 1607 | * for the internal routines (ie open_namei()/follow_link() etc) |
| 1608 | * This is more logical, and also allows the 00 "no perm needed" |
| 1609 | * to be used for symlinks (where the permissions are checked |
| 1610 | * later). |
| 1611 | * |
| 1612 | */ |
| 1613 | static inline int open_to_namei_flags(int flag) |
| 1614 | { |
| 1615 | if ((flag+1) & O_ACCMODE) |
| 1616 | flag++; |
| 1617 | return flag; |
| 1618 | } |
| 1619 | |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1620 | static int open_will_write_to_fs(int flag, struct inode *inode) |
| 1621 | { |
| 1622 | /* |
| 1623 | * We'll never write to the fs underlying |
| 1624 | * a device file. |
| 1625 | */ |
| 1626 | if (special_file(inode->i_mode)) |
| 1627 | return 0; |
| 1628 | return (flag & O_TRUNC); |
| 1629 | } |
| 1630 | |
Dave Hansen | d57999e | 2008-02-15 14:37:27 -0800 | [diff] [blame] | 1631 | /* |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1632 | * Note that the low bits of the passed in "open_flag" |
| 1633 | * are not the same as in the local variable "flag". See |
| 1634 | * open_to_namei_flags() for more details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1635 | */ |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1636 | struct file *do_filp_open(int dfd, const char *pathname, |
| 1637 | int open_flag, int mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1638 | { |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1639 | struct file *filp; |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1640 | struct nameidata nd; |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 1641 | int acc_mode, error; |
Al Viro | 4e7506e | 2005-06-06 13:36:00 -0700 | [diff] [blame] | 1642 | struct path path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1643 | struct dentry *dir; |
| 1644 | int count = 0; |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1645 | int will_write; |
Dave Hansen | d57999e | 2008-02-15 14:37:27 -0800 | [diff] [blame] | 1646 | int flag = open_to_namei_flags(open_flag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1647 | |
Al Viro | b77b064 | 2008-07-17 09:37:02 -0400 | [diff] [blame] | 1648 | acc_mode = MAY_OPEN | ACC_MODE(flag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1649 | |
Trond Myklebust | 834f2a4 | 2005-10-18 14:20:16 -0700 | [diff] [blame] | 1650 | /* O_TRUNC implies we need access checks for write permissions */ |
| 1651 | if (flag & O_TRUNC) |
| 1652 | acc_mode |= MAY_WRITE; |
| 1653 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1654 | /* Allow the LSM permission hook to distinguish append |
| 1655 | access from general write access. */ |
| 1656 | if (flag & O_APPEND) |
| 1657 | acc_mode |= MAY_APPEND; |
| 1658 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1659 | /* |
| 1660 | * The simplest case - just a plain lookup. |
| 1661 | */ |
| 1662 | if (!(flag & O_CREAT)) { |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 1663 | error = path_lookup_open(dfd, pathname, lookup_flags(flag), |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1664 | &nd, flag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1665 | if (error) |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1666 | return ERR_PTR(error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1667 | goto ok; |
| 1668 | } |
| 1669 | |
| 1670 | /* |
| 1671 | * Create - we need to know the parent. |
| 1672 | */ |
Al Viro | 8737f3a | 2008-08-02 22:36:57 -0400 | [diff] [blame] | 1673 | error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1674 | if (error) |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1675 | return ERR_PTR(error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1676 | |
| 1677 | /* |
| 1678 | * We have the parent and last component. First of all, check |
| 1679 | * that we are not asked to creat(2) an obvious directory - that |
| 1680 | * will not do. |
| 1681 | */ |
| 1682 | error = -EISDIR; |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1683 | if (nd.last_type != LAST_NORM || nd.last.name[nd.last.len]) |
Al Viro | 8737f3a | 2008-08-02 22:36:57 -0400 | [diff] [blame] | 1684 | goto exit_parent; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1685 | |
Al Viro | 8737f3a | 2008-08-02 22:36:57 -0400 | [diff] [blame] | 1686 | error = -ENFILE; |
| 1687 | filp = get_empty_filp(); |
| 1688 | if (filp == NULL) |
| 1689 | goto exit_parent; |
| 1690 | nd.intent.open.file = filp; |
| 1691 | nd.intent.open.flags = flag; |
| 1692 | nd.intent.open.create_mode = mode; |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1693 | dir = nd.path.dentry; |
| 1694 | nd.flags &= ~LOOKUP_PARENT; |
Al Viro | 8737f3a | 2008-08-02 22:36:57 -0400 | [diff] [blame] | 1695 | nd.flags |= LOOKUP_CREATE | LOOKUP_OPEN; |
Al Viro | 3516586 | 2008-08-05 03:00:49 -0400 | [diff] [blame] | 1696 | if (flag & O_EXCL) |
| 1697 | nd.flags |= LOOKUP_EXCL; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1698 | mutex_lock(&dir->d_inode->i_mutex); |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1699 | path.dentry = lookup_hash(&nd); |
| 1700 | path.mnt = nd.path.mnt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1701 | |
| 1702 | do_last: |
Al Viro | 4e7506e | 2005-06-06 13:36:00 -0700 | [diff] [blame] | 1703 | error = PTR_ERR(path.dentry); |
| 1704 | if (IS_ERR(path.dentry)) { |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1705 | mutex_unlock(&dir->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1706 | goto exit; |
| 1707 | } |
| 1708 | |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1709 | if (IS_ERR(nd.intent.open.file)) { |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1710 | error = PTR_ERR(nd.intent.open.file); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1711 | goto exit_mutex_unlock; |
Oleg Drokin | 4af4c52 | 2006-03-25 03:06:54 -0800 | [diff] [blame] | 1712 | } |
| 1713 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1714 | /* Negative dentry, just create the file */ |
Al Viro | 4e7506e | 2005-06-06 13:36:00 -0700 | [diff] [blame] | 1715 | if (!path.dentry->d_inode) { |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1716 | /* |
| 1717 | * This write is needed to ensure that a |
| 1718 | * ro->rw transition does not occur between |
| 1719 | * the time when the file is created and when |
| 1720 | * a permanent write count is taken through |
| 1721 | * the 'struct file' in nameidata_to_filp(). |
| 1722 | */ |
| 1723 | error = mnt_want_write(nd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1724 | if (error) |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1725 | goto exit_mutex_unlock; |
| 1726 | error = __open_namei_create(&nd, &path, flag, mode); |
| 1727 | if (error) { |
| 1728 | mnt_drop_write(nd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1729 | goto exit; |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1730 | } |
| 1731 | filp = nameidata_to_filp(&nd, open_flag); |
| 1732 | mnt_drop_write(nd.path.mnt); |
| 1733 | return filp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1734 | } |
| 1735 | |
| 1736 | /* |
| 1737 | * It already exists. |
| 1738 | */ |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1739 | mutex_unlock(&dir->d_inode->i_mutex); |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 1740 | audit_inode(pathname, path.dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1741 | |
| 1742 | error = -EEXIST; |
| 1743 | if (flag & O_EXCL) |
| 1744 | goto exit_dput; |
| 1745 | |
Al Viro | e13b210 | 2005-06-06 13:36:06 -0700 | [diff] [blame] | 1746 | if (__follow_mount(&path)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1747 | error = -ELOOP; |
Al Viro | ba7a4c1 | 2005-06-06 13:36:08 -0700 | [diff] [blame] | 1748 | if (flag & O_NOFOLLOW) |
| 1749 | goto exit_dput; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1750 | } |
Amy Griffis | 3e2efce | 2006-07-13 13:16:02 -0400 | [diff] [blame] | 1751 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1752 | error = -ENOENT; |
Al Viro | 4e7506e | 2005-06-06 13:36:00 -0700 | [diff] [blame] | 1753 | if (!path.dentry->d_inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1754 | goto exit_dput; |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 1755 | if (path.dentry->d_inode->i_op->follow_link) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1756 | goto do_link; |
| 1757 | |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1758 | path_to_nameidata(&path, &nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1759 | error = -EISDIR; |
Al Viro | 4e7506e | 2005-06-06 13:36:00 -0700 | [diff] [blame] | 1760 | if (path.dentry->d_inode && S_ISDIR(path.dentry->d_inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1761 | goto exit; |
| 1762 | ok: |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1763 | /* |
| 1764 | * Consider: |
| 1765 | * 1. may_open() truncates a file |
| 1766 | * 2. a rw->ro mount transition occurs |
| 1767 | * 3. nameidata_to_filp() fails due to |
| 1768 | * the ro mount. |
| 1769 | * That would be inconsistent, and should |
| 1770 | * be avoided. Taking this mnt write here |
| 1771 | * ensures that (2) can not occur. |
| 1772 | */ |
| 1773 | will_write = open_will_write_to_fs(flag, nd.path.dentry->d_inode); |
| 1774 | if (will_write) { |
| 1775 | error = mnt_want_write(nd.path.mnt); |
| 1776 | if (error) |
| 1777 | goto exit; |
| 1778 | } |
Christoph Hellwig | 3fb6419 | 2008-10-24 09:58:10 +0200 | [diff] [blame] | 1779 | error = may_open(&nd.path, acc_mode, flag); |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1780 | if (error) { |
| 1781 | if (will_write) |
| 1782 | mnt_drop_write(nd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1783 | goto exit; |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1784 | } |
| 1785 | filp = nameidata_to_filp(&nd, open_flag); |
| 1786 | /* |
| 1787 | * It is now safe to drop the mnt write |
| 1788 | * because the filp has had a write taken |
| 1789 | * on its behalf. |
| 1790 | */ |
| 1791 | if (will_write) |
| 1792 | mnt_drop_write(nd.path.mnt); |
| 1793 | return filp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1794 | |
Dave Hansen | 4a3fd21 | 2008-02-15 14:37:48 -0800 | [diff] [blame] | 1795 | exit_mutex_unlock: |
| 1796 | mutex_unlock(&dir->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1797 | exit_dput: |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1798 | path_put_conditional(&path, &nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1799 | exit: |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1800 | if (!IS_ERR(nd.intent.open.file)) |
| 1801 | release_open_intent(&nd); |
Al Viro | 8737f3a | 2008-08-02 22:36:57 -0400 | [diff] [blame] | 1802 | exit_parent: |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1803 | path_put(&nd.path); |
| 1804 | return ERR_PTR(error); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1805 | |
| 1806 | do_link: |
| 1807 | error = -ELOOP; |
| 1808 | if (flag & O_NOFOLLOW) |
| 1809 | goto exit_dput; |
| 1810 | /* |
| 1811 | * This is subtle. Instead of calling do_follow_link() we do the |
| 1812 | * thing by hands. The reason is that this way we have zero link_count |
| 1813 | * and path_walk() (called from ->follow_link) honoring LOOKUP_PARENT. |
| 1814 | * After that we have the parent and last component, i.e. |
| 1815 | * we are in the same situation as after the first path_walk(). |
| 1816 | * Well, almost - if the last component is normal we get its copy |
| 1817 | * stored in nd->last.name and we will have to putname() it when we |
| 1818 | * are done. Procfs-like symlinks just set LAST_BIND. |
| 1819 | */ |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1820 | nd.flags |= LOOKUP_PARENT; |
| 1821 | error = security_inode_follow_link(path.dentry, &nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1822 | if (error) |
| 1823 | goto exit_dput; |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1824 | error = __do_follow_link(&path, &nd); |
Kirill Korotaev | de45921 | 2006-07-14 00:23:49 -0700 | [diff] [blame] | 1825 | if (error) { |
| 1826 | /* Does someone understand code flow here? Or it is only |
| 1827 | * me so stupid? Anathema to whoever designed this non-sense |
| 1828 | * with "intent.open". |
| 1829 | */ |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1830 | release_open_intent(&nd); |
| 1831 | return ERR_PTR(error); |
Kirill Korotaev | de45921 | 2006-07-14 00:23:49 -0700 | [diff] [blame] | 1832 | } |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1833 | nd.flags &= ~LOOKUP_PARENT; |
| 1834 | if (nd.last_type == LAST_BIND) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1835 | goto ok; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1836 | error = -EISDIR; |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1837 | if (nd.last_type != LAST_NORM) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1838 | goto exit; |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1839 | if (nd.last.name[nd.last.len]) { |
| 1840 | __putname(nd.last.name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1841 | goto exit; |
| 1842 | } |
| 1843 | error = -ELOOP; |
| 1844 | if (count++==32) { |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1845 | __putname(nd.last.name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1846 | goto exit; |
| 1847 | } |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1848 | dir = nd.path.dentry; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 1849 | mutex_lock(&dir->d_inode->i_mutex); |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1850 | path.dentry = lookup_hash(&nd); |
| 1851 | path.mnt = nd.path.mnt; |
| 1852 | __putname(nd.last.name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1853 | goto do_last; |
| 1854 | } |
| 1855 | |
| 1856 | /** |
Christoph Hellwig | a70e65d | 2008-02-15 14:37:28 -0800 | [diff] [blame] | 1857 | * filp_open - open file and return file pointer |
| 1858 | * |
| 1859 | * @filename: path to open |
| 1860 | * @flags: open flags as per the open(2) second argument |
| 1861 | * @mode: mode for the new file if O_CREAT is set, else ignored |
| 1862 | * |
| 1863 | * This is the helper to open a file from kernelspace if you really |
| 1864 | * have to. But in generally you should not do this, so please move |
| 1865 | * along, nothing to see here.. |
| 1866 | */ |
| 1867 | struct file *filp_open(const char *filename, int flags, int mode) |
| 1868 | { |
| 1869 | return do_filp_open(AT_FDCWD, filename, flags, mode); |
| 1870 | } |
| 1871 | EXPORT_SYMBOL(filp_open); |
| 1872 | |
| 1873 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1874 | * lookup_create - lookup a dentry, creating it if it doesn't exist |
| 1875 | * @nd: nameidata info |
| 1876 | * @is_dir: directory flag |
| 1877 | * |
| 1878 | * Simple function to lookup and return a dentry and create it |
| 1879 | * if it doesn't exist. Is SMP-safe. |
Christoph Hellwig | c663e5d | 2005-06-23 00:09:49 -0700 | [diff] [blame] | 1880 | * |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1881 | * Returns with nd->path.dentry->d_inode->i_mutex locked. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1882 | */ |
| 1883 | struct dentry *lookup_create(struct nameidata *nd, int is_dir) |
| 1884 | { |
Christoph Hellwig | c663e5d | 2005-06-23 00:09:49 -0700 | [diff] [blame] | 1885 | struct dentry *dentry = ERR_PTR(-EEXIST); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1886 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1887 | mutex_lock_nested(&nd->path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); |
Christoph Hellwig | c663e5d | 2005-06-23 00:09:49 -0700 | [diff] [blame] | 1888 | /* |
| 1889 | * Yucky last component or no last component at all? |
| 1890 | * (foo/., foo/.., /////) |
| 1891 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1892 | if (nd->last_type != LAST_NORM) |
| 1893 | goto fail; |
| 1894 | nd->flags &= ~LOOKUP_PARENT; |
Al Viro | 3516586 | 2008-08-05 03:00:49 -0400 | [diff] [blame] | 1895 | nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL; |
ASANO Masahiro | a634904 | 2006-08-22 20:06:02 -0400 | [diff] [blame] | 1896 | nd->intent.open.flags = O_EXCL; |
Christoph Hellwig | c663e5d | 2005-06-23 00:09:49 -0700 | [diff] [blame] | 1897 | |
| 1898 | /* |
| 1899 | * Do the final lookup. |
| 1900 | */ |
Christoph Hellwig | 49705b7 | 2005-11-08 21:35:06 -0800 | [diff] [blame] | 1901 | dentry = lookup_hash(nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1902 | if (IS_ERR(dentry)) |
| 1903 | goto fail; |
Christoph Hellwig | c663e5d | 2005-06-23 00:09:49 -0700 | [diff] [blame] | 1904 | |
Al Viro | e9baf6e | 2008-05-15 04:49:12 -0400 | [diff] [blame] | 1905 | if (dentry->d_inode) |
| 1906 | goto eexist; |
Christoph Hellwig | c663e5d | 2005-06-23 00:09:49 -0700 | [diff] [blame] | 1907 | /* |
| 1908 | * Special case - lookup gave negative, but... we had foo/bar/ |
| 1909 | * From the vfs_mknod() POV we just have a negative dentry - |
| 1910 | * all is fine. Let's be bastards - you had / on the end, you've |
| 1911 | * been asking for (non-existent) directory. -ENOENT for you. |
| 1912 | */ |
Al Viro | e9baf6e | 2008-05-15 04:49:12 -0400 | [diff] [blame] | 1913 | if (unlikely(!is_dir && nd->last.name[nd->last.len])) { |
| 1914 | dput(dentry); |
| 1915 | dentry = ERR_PTR(-ENOENT); |
| 1916 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1917 | return dentry; |
Al Viro | e9baf6e | 2008-05-15 04:49:12 -0400 | [diff] [blame] | 1918 | eexist: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1919 | dput(dentry); |
Al Viro | e9baf6e | 2008-05-15 04:49:12 -0400 | [diff] [blame] | 1920 | dentry = ERR_PTR(-EEXIST); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1921 | fail: |
| 1922 | return dentry; |
| 1923 | } |
Christoph Hellwig | f81a0bf | 2005-05-19 12:26:43 -0700 | [diff] [blame] | 1924 | EXPORT_SYMBOL_GPL(lookup_create); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1925 | |
| 1926 | int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) |
| 1927 | { |
Miklos Szeredi | a95164d | 2008-07-30 15:08:48 +0200 | [diff] [blame] | 1928 | int error = may_create(dir, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1929 | |
| 1930 | if (error) |
| 1931 | return error; |
| 1932 | |
| 1933 | if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD)) |
| 1934 | return -EPERM; |
| 1935 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 1936 | if (!dir->i_op->mknod) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1937 | return -EPERM; |
| 1938 | |
Serge E. Hallyn | 08ce5f1 | 2008-04-29 01:00:10 -0700 | [diff] [blame] | 1939 | error = devcgroup_inode_mknod(mode, dev); |
| 1940 | if (error) |
| 1941 | return error; |
| 1942 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1943 | error = security_inode_mknod(dir, dentry, mode, dev); |
| 1944 | if (error) |
| 1945 | return error; |
| 1946 | |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 1947 | vfs_dq_init(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1948 | error = dir->i_op->mknod(dir, dentry, mode, dev); |
Stephen Smalley | a74574a | 2005-09-09 13:01:44 -0700 | [diff] [blame] | 1949 | if (!error) |
Amy Griffis | f38aa94 | 2005-11-03 15:57:06 +0000 | [diff] [blame] | 1950 | fsnotify_create(dir, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1951 | return error; |
| 1952 | } |
| 1953 | |
Dave Hansen | 463c319 | 2008-02-15 14:37:57 -0800 | [diff] [blame] | 1954 | static int may_mknod(mode_t mode) |
| 1955 | { |
| 1956 | switch (mode & S_IFMT) { |
| 1957 | case S_IFREG: |
| 1958 | case S_IFCHR: |
| 1959 | case S_IFBLK: |
| 1960 | case S_IFIFO: |
| 1961 | case S_IFSOCK: |
| 1962 | case 0: /* zero mode translates to S_IFREG */ |
| 1963 | return 0; |
| 1964 | case S_IFDIR: |
| 1965 | return -EPERM; |
| 1966 | default: |
| 1967 | return -EINVAL; |
| 1968 | } |
| 1969 | } |
| 1970 | |
Heiko Carstens | 2e4d092 | 2009-01-14 14:14:31 +0100 | [diff] [blame] | 1971 | SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode, |
| 1972 | unsigned, dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1973 | { |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 1974 | int error; |
| 1975 | char *tmp; |
| 1976 | struct dentry *dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1977 | struct nameidata nd; |
| 1978 | |
| 1979 | if (S_ISDIR(mode)) |
| 1980 | return -EPERM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1981 | |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 1982 | error = user_path_parent(dfd, filename, &nd, &tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1983 | if (error) |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 1984 | return error; |
| 1985 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1986 | dentry = lookup_create(&nd, 0); |
Dave Hansen | 463c319 | 2008-02-15 14:37:57 -0800 | [diff] [blame] | 1987 | if (IS_ERR(dentry)) { |
| 1988 | error = PTR_ERR(dentry); |
| 1989 | goto out_unlock; |
| 1990 | } |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 1991 | if (!IS_POSIXACL(nd.path.dentry->d_inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1992 | mode &= ~current->fs->umask; |
Dave Hansen | 463c319 | 2008-02-15 14:37:57 -0800 | [diff] [blame] | 1993 | error = may_mknod(mode); |
| 1994 | if (error) |
| 1995 | goto out_dput; |
| 1996 | error = mnt_want_write(nd.path.mnt); |
| 1997 | if (error) |
| 1998 | goto out_dput; |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 1999 | error = security_path_mknod(&nd.path, dentry, mode, dev); |
| 2000 | if (error) |
| 2001 | goto out_drop_write; |
Dave Hansen | 463c319 | 2008-02-15 14:37:57 -0800 | [diff] [blame] | 2002 | switch (mode & S_IFMT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2003 | case 0: case S_IFREG: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2004 | error = vfs_create(nd.path.dentry->d_inode,dentry,mode,&nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2005 | break; |
| 2006 | case S_IFCHR: case S_IFBLK: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2007 | error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2008 | new_decode_dev(dev)); |
| 2009 | break; |
| 2010 | case S_IFIFO: case S_IFSOCK: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2011 | error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2012 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2013 | } |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2014 | out_drop_write: |
Dave Hansen | 463c319 | 2008-02-15 14:37:57 -0800 | [diff] [blame] | 2015 | mnt_drop_write(nd.path.mnt); |
| 2016 | out_dput: |
| 2017 | dput(dentry); |
| 2018 | out_unlock: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2019 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 2020 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2021 | putname(tmp); |
| 2022 | |
| 2023 | return error; |
| 2024 | } |
| 2025 | |
Heiko Carstens | 3480b25 | 2009-01-14 14:14:16 +0100 | [diff] [blame] | 2026 | SYSCALL_DEFINE3(mknod, const char __user *, filename, int, mode, unsigned, dev) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2027 | { |
| 2028 | return sys_mknodat(AT_FDCWD, filename, mode, dev); |
| 2029 | } |
| 2030 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2031 | int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) |
| 2032 | { |
Miklos Szeredi | a95164d | 2008-07-30 15:08:48 +0200 | [diff] [blame] | 2033 | int error = may_create(dir, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2034 | |
| 2035 | if (error) |
| 2036 | return error; |
| 2037 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 2038 | if (!dir->i_op->mkdir) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2039 | return -EPERM; |
| 2040 | |
| 2041 | mode &= (S_IRWXUGO|S_ISVTX); |
| 2042 | error = security_inode_mkdir(dir, dentry, mode); |
| 2043 | if (error) |
| 2044 | return error; |
| 2045 | |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 2046 | vfs_dq_init(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2047 | error = dir->i_op->mkdir(dir, dentry, mode); |
Stephen Smalley | a74574a | 2005-09-09 13:01:44 -0700 | [diff] [blame] | 2048 | if (!error) |
Amy Griffis | f38aa94 | 2005-11-03 15:57:06 +0000 | [diff] [blame] | 2049 | fsnotify_mkdir(dir, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2050 | return error; |
| 2051 | } |
| 2052 | |
Heiko Carstens | 2e4d092 | 2009-01-14 14:14:31 +0100 | [diff] [blame] | 2053 | SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2054 | { |
| 2055 | int error = 0; |
| 2056 | char * tmp; |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2057 | struct dentry *dentry; |
| 2058 | struct nameidata nd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2059 | |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2060 | error = user_path_parent(dfd, pathname, &nd, &tmp); |
| 2061 | if (error) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2062 | goto out_err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2063 | |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2064 | dentry = lookup_create(&nd, 1); |
| 2065 | error = PTR_ERR(dentry); |
| 2066 | if (IS_ERR(dentry)) |
| 2067 | goto out_unlock; |
| 2068 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2069 | if (!IS_POSIXACL(nd.path.dentry->d_inode)) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2070 | mode &= ~current->fs->umask; |
Dave Hansen | 463c319 | 2008-02-15 14:37:57 -0800 | [diff] [blame] | 2071 | error = mnt_want_write(nd.path.mnt); |
| 2072 | if (error) |
| 2073 | goto out_dput; |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2074 | error = security_path_mkdir(&nd.path, dentry, mode); |
| 2075 | if (error) |
| 2076 | goto out_drop_write; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2077 | error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2078 | out_drop_write: |
Dave Hansen | 463c319 | 2008-02-15 14:37:57 -0800 | [diff] [blame] | 2079 | mnt_drop_write(nd.path.mnt); |
| 2080 | out_dput: |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2081 | dput(dentry); |
| 2082 | out_unlock: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2083 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 2084 | path_put(&nd.path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2085 | putname(tmp); |
| 2086 | out_err: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2087 | return error; |
| 2088 | } |
| 2089 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 2090 | SYSCALL_DEFINE2(mkdir, const char __user *, pathname, int, mode) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2091 | { |
| 2092 | return sys_mkdirat(AT_FDCWD, pathname, mode); |
| 2093 | } |
| 2094 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2095 | /* |
| 2096 | * We try to drop the dentry early: we should have |
| 2097 | * a usage count of 2 if we're the only user of this |
| 2098 | * dentry, and if that is true (possibly after pruning |
| 2099 | * the dcache), then we drop the dentry now. |
| 2100 | * |
| 2101 | * A low-level filesystem can, if it choses, legally |
| 2102 | * do a |
| 2103 | * |
| 2104 | * if (!d_unhashed(dentry)) |
| 2105 | * return -EBUSY; |
| 2106 | * |
| 2107 | * if it cannot handle the case of removing a directory |
| 2108 | * that is still in use by something else.. |
| 2109 | */ |
| 2110 | void dentry_unhash(struct dentry *dentry) |
| 2111 | { |
| 2112 | dget(dentry); |
Vasily Averin | dc16842 | 2006-12-06 20:37:07 -0800 | [diff] [blame] | 2113 | shrink_dcache_parent(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2114 | spin_lock(&dcache_lock); |
| 2115 | spin_lock(&dentry->d_lock); |
| 2116 | if (atomic_read(&dentry->d_count) == 2) |
| 2117 | __d_drop(dentry); |
| 2118 | spin_unlock(&dentry->d_lock); |
| 2119 | spin_unlock(&dcache_lock); |
| 2120 | } |
| 2121 | |
| 2122 | int vfs_rmdir(struct inode *dir, struct dentry *dentry) |
| 2123 | { |
| 2124 | int error = may_delete(dir, dentry, 1); |
| 2125 | |
| 2126 | if (error) |
| 2127 | return error; |
| 2128 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 2129 | if (!dir->i_op->rmdir) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2130 | return -EPERM; |
| 2131 | |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 2132 | vfs_dq_init(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2133 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2134 | mutex_lock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2135 | dentry_unhash(dentry); |
| 2136 | if (d_mountpoint(dentry)) |
| 2137 | error = -EBUSY; |
| 2138 | else { |
| 2139 | error = security_inode_rmdir(dir, dentry); |
| 2140 | if (!error) { |
| 2141 | error = dir->i_op->rmdir(dir, dentry); |
| 2142 | if (!error) |
| 2143 | dentry->d_inode->i_flags |= S_DEAD; |
| 2144 | } |
| 2145 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2146 | mutex_unlock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2147 | if (!error) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2148 | d_delete(dentry); |
| 2149 | } |
| 2150 | dput(dentry); |
| 2151 | |
| 2152 | return error; |
| 2153 | } |
| 2154 | |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2155 | static long do_rmdir(int dfd, const char __user *pathname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2156 | { |
| 2157 | int error = 0; |
| 2158 | char * name; |
| 2159 | struct dentry *dentry; |
| 2160 | struct nameidata nd; |
| 2161 | |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2162 | error = user_path_parent(dfd, pathname, &nd, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2163 | if (error) |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2164 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2165 | |
| 2166 | switch(nd.last_type) { |
OGAWA Hirofumi | 0612d9f | 2008-10-16 07:50:29 +0900 | [diff] [blame] | 2167 | case LAST_DOTDOT: |
| 2168 | error = -ENOTEMPTY; |
| 2169 | goto exit1; |
| 2170 | case LAST_DOT: |
| 2171 | error = -EINVAL; |
| 2172 | goto exit1; |
| 2173 | case LAST_ROOT: |
| 2174 | error = -EBUSY; |
| 2175 | goto exit1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2176 | } |
OGAWA Hirofumi | 0612d9f | 2008-10-16 07:50:29 +0900 | [diff] [blame] | 2177 | |
| 2178 | nd.flags &= ~LOOKUP_PARENT; |
| 2179 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2180 | mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); |
Christoph Hellwig | 49705b7 | 2005-11-08 21:35:06 -0800 | [diff] [blame] | 2181 | dentry = lookup_hash(&nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2182 | error = PTR_ERR(dentry); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2183 | if (IS_ERR(dentry)) |
| 2184 | goto exit2; |
Dave Hansen | 0622753 | 2008-02-15 14:37:34 -0800 | [diff] [blame] | 2185 | error = mnt_want_write(nd.path.mnt); |
| 2186 | if (error) |
| 2187 | goto exit3; |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2188 | error = security_path_rmdir(&nd.path, dentry); |
| 2189 | if (error) |
| 2190 | goto exit4; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2191 | error = vfs_rmdir(nd.path.dentry->d_inode, dentry); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2192 | exit4: |
Dave Hansen | 0622753 | 2008-02-15 14:37:34 -0800 | [diff] [blame] | 2193 | mnt_drop_write(nd.path.mnt); |
| 2194 | exit3: |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2195 | dput(dentry); |
| 2196 | exit2: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2197 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2198 | exit1: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 2199 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2200 | putname(name); |
| 2201 | return error; |
| 2202 | } |
| 2203 | |
Heiko Carstens | 3cdad42 | 2009-01-14 14:14:22 +0100 | [diff] [blame] | 2204 | SYSCALL_DEFINE1(rmdir, const char __user *, pathname) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2205 | { |
| 2206 | return do_rmdir(AT_FDCWD, pathname); |
| 2207 | } |
| 2208 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2209 | int vfs_unlink(struct inode *dir, struct dentry *dentry) |
| 2210 | { |
| 2211 | int error = may_delete(dir, dentry, 0); |
| 2212 | |
| 2213 | if (error) |
| 2214 | return error; |
| 2215 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 2216 | if (!dir->i_op->unlink) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2217 | return -EPERM; |
| 2218 | |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 2219 | vfs_dq_init(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2220 | |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2221 | mutex_lock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2222 | if (d_mountpoint(dentry)) |
| 2223 | error = -EBUSY; |
| 2224 | else { |
| 2225 | error = security_inode_unlink(dir, dentry); |
| 2226 | if (!error) |
| 2227 | error = dir->i_op->unlink(dir, dentry); |
| 2228 | } |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2229 | mutex_unlock(&dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2230 | |
| 2231 | /* We don't d_delete() NFS sillyrenamed files--they still exist. */ |
| 2232 | if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) { |
Jan Kara | ece9591 | 2008-02-06 01:37:13 -0800 | [diff] [blame] | 2233 | fsnotify_link_count(dentry->d_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2234 | d_delete(dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2235 | } |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 2236 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2237 | return error; |
| 2238 | } |
| 2239 | |
| 2240 | /* |
| 2241 | * Make sure that the actual truncation of the file will occur outside its |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2242 | * directory's i_mutex. Truncate can take a long time if there is a lot of |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2243 | * writeout happening, and we don't want to prevent access to the directory |
| 2244 | * while waiting on the I/O. |
| 2245 | */ |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2246 | static long do_unlinkat(int dfd, const char __user *pathname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2247 | { |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2248 | int error; |
| 2249 | char *name; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2250 | struct dentry *dentry; |
| 2251 | struct nameidata nd; |
| 2252 | struct inode *inode = NULL; |
| 2253 | |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2254 | error = user_path_parent(dfd, pathname, &nd, &name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2255 | if (error) |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2256 | return error; |
| 2257 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2258 | error = -EISDIR; |
| 2259 | if (nd.last_type != LAST_NORM) |
| 2260 | goto exit1; |
OGAWA Hirofumi | 0612d9f | 2008-10-16 07:50:29 +0900 | [diff] [blame] | 2261 | |
| 2262 | nd.flags &= ~LOOKUP_PARENT; |
| 2263 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2264 | mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); |
Christoph Hellwig | 49705b7 | 2005-11-08 21:35:06 -0800 | [diff] [blame] | 2265 | dentry = lookup_hash(&nd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2266 | error = PTR_ERR(dentry); |
| 2267 | if (!IS_ERR(dentry)) { |
| 2268 | /* Why not before? Because we want correct error value */ |
| 2269 | if (nd.last.name[nd.last.len]) |
| 2270 | goto slashes; |
| 2271 | inode = dentry->d_inode; |
| 2272 | if (inode) |
| 2273 | atomic_inc(&inode->i_count); |
Dave Hansen | 0622753 | 2008-02-15 14:37:34 -0800 | [diff] [blame] | 2274 | error = mnt_want_write(nd.path.mnt); |
| 2275 | if (error) |
| 2276 | goto exit2; |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2277 | error = security_path_unlink(&nd.path, dentry); |
| 2278 | if (error) |
| 2279 | goto exit3; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2280 | error = vfs_unlink(nd.path.dentry->d_inode, dentry); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2281 | exit3: |
Dave Hansen | 0622753 | 2008-02-15 14:37:34 -0800 | [diff] [blame] | 2282 | mnt_drop_write(nd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2283 | exit2: |
| 2284 | dput(dentry); |
| 2285 | } |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2286 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2287 | if (inode) |
| 2288 | iput(inode); /* truncate the inode here */ |
| 2289 | exit1: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 2290 | path_put(&nd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2291 | putname(name); |
| 2292 | return error; |
| 2293 | |
| 2294 | slashes: |
| 2295 | error = !dentry->d_inode ? -ENOENT : |
| 2296 | S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR; |
| 2297 | goto exit2; |
| 2298 | } |
| 2299 | |
Heiko Carstens | 2e4d092 | 2009-01-14 14:14:31 +0100 | [diff] [blame] | 2300 | SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2301 | { |
| 2302 | if ((flag & ~AT_REMOVEDIR) != 0) |
| 2303 | return -EINVAL; |
| 2304 | |
| 2305 | if (flag & AT_REMOVEDIR) |
| 2306 | return do_rmdir(dfd, pathname); |
| 2307 | |
| 2308 | return do_unlinkat(dfd, pathname); |
| 2309 | } |
| 2310 | |
Heiko Carstens | 3480b25 | 2009-01-14 14:14:16 +0100 | [diff] [blame] | 2311 | SYSCALL_DEFINE1(unlink, const char __user *, pathname) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2312 | { |
| 2313 | return do_unlinkat(AT_FDCWD, pathname); |
| 2314 | } |
| 2315 | |
Miklos Szeredi | db2e747 | 2008-06-24 16:50:16 +0200 | [diff] [blame] | 2316 | int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2317 | { |
Miklos Szeredi | a95164d | 2008-07-30 15:08:48 +0200 | [diff] [blame] | 2318 | int error = may_create(dir, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2319 | |
| 2320 | if (error) |
| 2321 | return error; |
| 2322 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 2323 | if (!dir->i_op->symlink) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2324 | return -EPERM; |
| 2325 | |
| 2326 | error = security_inode_symlink(dir, dentry, oldname); |
| 2327 | if (error) |
| 2328 | return error; |
| 2329 | |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 2330 | vfs_dq_init(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2331 | error = dir->i_op->symlink(dir, dentry, oldname); |
Stephen Smalley | a74574a | 2005-09-09 13:01:44 -0700 | [diff] [blame] | 2332 | if (!error) |
Amy Griffis | f38aa94 | 2005-11-03 15:57:06 +0000 | [diff] [blame] | 2333 | fsnotify_create(dir, dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2334 | return error; |
| 2335 | } |
| 2336 | |
Heiko Carstens | 2e4d092 | 2009-01-14 14:14:31 +0100 | [diff] [blame] | 2337 | SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, |
| 2338 | int, newdfd, const char __user *, newname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2339 | { |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2340 | int error; |
| 2341 | char *from; |
| 2342 | char *to; |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2343 | struct dentry *dentry; |
| 2344 | struct nameidata nd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2345 | |
| 2346 | from = getname(oldname); |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2347 | if (IS_ERR(from)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2348 | return PTR_ERR(from); |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2349 | |
| 2350 | error = user_path_parent(newdfd, newname, &nd, &to); |
| 2351 | if (error) |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2352 | goto out_putname; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2353 | |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2354 | dentry = lookup_create(&nd, 0); |
| 2355 | error = PTR_ERR(dentry); |
| 2356 | if (IS_ERR(dentry)) |
| 2357 | goto out_unlock; |
| 2358 | |
Dave Hansen | 75c3f29 | 2008-02-15 14:37:45 -0800 | [diff] [blame] | 2359 | error = mnt_want_write(nd.path.mnt); |
| 2360 | if (error) |
| 2361 | goto out_dput; |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2362 | error = security_path_symlink(&nd.path, dentry, from); |
| 2363 | if (error) |
| 2364 | goto out_drop_write; |
Miklos Szeredi | db2e747 | 2008-06-24 16:50:16 +0200 | [diff] [blame] | 2365 | error = vfs_symlink(nd.path.dentry->d_inode, dentry, from); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2366 | out_drop_write: |
Dave Hansen | 75c3f29 | 2008-02-15 14:37:45 -0800 | [diff] [blame] | 2367 | mnt_drop_write(nd.path.mnt); |
| 2368 | out_dput: |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2369 | dput(dentry); |
| 2370 | out_unlock: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2371 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 2372 | path_put(&nd.path); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2373 | putname(to); |
| 2374 | out_putname: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2375 | putname(from); |
| 2376 | return error; |
| 2377 | } |
| 2378 | |
Heiko Carstens | 3480b25 | 2009-01-14 14:14:16 +0100 | [diff] [blame] | 2379 | SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2380 | { |
| 2381 | return sys_symlinkat(oldname, AT_FDCWD, newname); |
| 2382 | } |
| 2383 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2384 | int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) |
| 2385 | { |
| 2386 | struct inode *inode = old_dentry->d_inode; |
| 2387 | int error; |
| 2388 | |
| 2389 | if (!inode) |
| 2390 | return -ENOENT; |
| 2391 | |
Miklos Szeredi | a95164d | 2008-07-30 15:08:48 +0200 | [diff] [blame] | 2392 | error = may_create(dir, new_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2393 | if (error) |
| 2394 | return error; |
| 2395 | |
| 2396 | if (dir->i_sb != inode->i_sb) |
| 2397 | return -EXDEV; |
| 2398 | |
| 2399 | /* |
| 2400 | * A link to an append-only or immutable file cannot be created. |
| 2401 | */ |
| 2402 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) |
| 2403 | return -EPERM; |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 2404 | if (!dir->i_op->link) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2405 | return -EPERM; |
Tetsuo Handa | 7e79eed | 2008-06-24 16:50:15 +0200 | [diff] [blame] | 2406 | if (S_ISDIR(inode->i_mode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2407 | return -EPERM; |
| 2408 | |
| 2409 | error = security_inode_link(old_dentry, dir, new_dentry); |
| 2410 | if (error) |
| 2411 | return error; |
| 2412 | |
Tetsuo Handa | 7e79eed | 2008-06-24 16:50:15 +0200 | [diff] [blame] | 2413 | mutex_lock(&inode->i_mutex); |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 2414 | vfs_dq_init(dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2415 | error = dir->i_op->link(old_dentry, dir, new_dentry); |
Tetsuo Handa | 7e79eed | 2008-06-24 16:50:15 +0200 | [diff] [blame] | 2416 | mutex_unlock(&inode->i_mutex); |
Stephen Smalley | e31e14e | 2005-09-09 13:01:45 -0700 | [diff] [blame] | 2417 | if (!error) |
Tetsuo Handa | 7e79eed | 2008-06-24 16:50:15 +0200 | [diff] [blame] | 2418 | fsnotify_link(dir, inode, new_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2419 | return error; |
| 2420 | } |
| 2421 | |
| 2422 | /* |
| 2423 | * Hardlinks are often used in delicate situations. We avoid |
| 2424 | * security-related surprises by not following symlinks on the |
| 2425 | * newname. --KAB |
| 2426 | * |
| 2427 | * We don't follow them on the oldname either to be compatible |
| 2428 | * with linux 2.0, and to avoid hard-linking to directories |
| 2429 | * and other special files. --ADM |
| 2430 | */ |
Heiko Carstens | 2e4d092 | 2009-01-14 14:14:31 +0100 | [diff] [blame] | 2431 | SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, |
| 2432 | int, newdfd, const char __user *, newname, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2433 | { |
| 2434 | struct dentry *new_dentry; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 2435 | struct nameidata nd; |
| 2436 | struct path old_path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2437 | int error; |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2438 | char *to; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2439 | |
Ulrich Drepper | 45c9b11 | 2006-06-25 05:49:11 -0700 | [diff] [blame] | 2440 | if ((flags & ~AT_SYMLINK_FOLLOW) != 0) |
Ulrich Drepper | c04030e | 2006-02-24 13:04:21 -0800 | [diff] [blame] | 2441 | return -EINVAL; |
| 2442 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 2443 | error = user_path_at(olddfd, oldname, |
| 2444 | flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0, |
| 2445 | &old_path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2446 | if (error) |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2447 | return error; |
| 2448 | |
| 2449 | error = user_path_parent(newdfd, newname, &nd, &to); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2450 | if (error) |
| 2451 | goto out; |
| 2452 | error = -EXDEV; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 2453 | if (old_path.mnt != nd.path.mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2454 | goto out_release; |
| 2455 | new_dentry = lookup_create(&nd, 0); |
| 2456 | error = PTR_ERR(new_dentry); |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2457 | if (IS_ERR(new_dentry)) |
| 2458 | goto out_unlock; |
Dave Hansen | 75c3f29 | 2008-02-15 14:37:45 -0800 | [diff] [blame] | 2459 | error = mnt_want_write(nd.path.mnt); |
| 2460 | if (error) |
| 2461 | goto out_dput; |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2462 | error = security_path_link(old_path.dentry, &nd.path, new_dentry); |
| 2463 | if (error) |
| 2464 | goto out_drop_write; |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 2465 | error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2466 | out_drop_write: |
Dave Hansen | 75c3f29 | 2008-02-15 14:37:45 -0800 | [diff] [blame] | 2467 | mnt_drop_write(nd.path.mnt); |
| 2468 | out_dput: |
Dave Hansen | 6902d92 | 2006-09-30 23:29:01 -0700 | [diff] [blame] | 2469 | dput(new_dentry); |
| 2470 | out_unlock: |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2471 | mutex_unlock(&nd.path.dentry->d_inode->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2472 | out_release: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 2473 | path_put(&nd.path); |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2474 | putname(to); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2475 | out: |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 2476 | path_put(&old_path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2477 | |
| 2478 | return error; |
| 2479 | } |
| 2480 | |
Heiko Carstens | 3480b25 | 2009-01-14 14:14:16 +0100 | [diff] [blame] | 2481 | SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2482 | { |
Ulrich Drepper | c04030e | 2006-02-24 13:04:21 -0800 | [diff] [blame] | 2483 | return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2484 | } |
| 2485 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2486 | /* |
| 2487 | * The worst of all namespace operations - renaming directory. "Perverted" |
| 2488 | * doesn't even start to describe it. Somebody in UCB had a heck of a trip... |
| 2489 | * Problems: |
| 2490 | * a) we can get into loop creation. Check is done in is_subdir(). |
| 2491 | * b) race potential - two innocent renames can create a loop together. |
| 2492 | * That's where 4.4 screws up. Current fix: serialization on |
Arjan van de Ven | a11f3a0 | 2006-03-23 03:00:33 -0800 | [diff] [blame] | 2493 | * sb->s_vfs_rename_mutex. We might be more accurate, but that's another |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2494 | * story. |
| 2495 | * c) we have to lock _three_ objects - parents and victim (if it exists). |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2496 | * And that - after we got ->i_mutex on parents (until then we don't know |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2497 | * whether the target exists). Solution: try to be smart with locking |
| 2498 | * order for inodes. We rely on the fact that tree topology may change |
Arjan van de Ven | a11f3a0 | 2006-03-23 03:00:33 -0800 | [diff] [blame] | 2499 | * only under ->s_vfs_rename_mutex _and_ that parent of the object we |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2500 | * move will be locked. Thus we can rank directories by the tree |
| 2501 | * (ancestors first) and rank all non-directories after them. |
| 2502 | * That works since everybody except rename does "lock parent, lookup, |
Arjan van de Ven | a11f3a0 | 2006-03-23 03:00:33 -0800 | [diff] [blame] | 2503 | * lock child" and rename is under ->s_vfs_rename_mutex. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2504 | * HOWEVER, it relies on the assumption that any object with ->lookup() |
| 2505 | * has no more than 1 dentry. If "hybrid" objects will ever appear, |
| 2506 | * we'd better make sure that there's no link(2) for them. |
| 2507 | * d) some filesystems don't support opened-but-unlinked directories, |
| 2508 | * either because of layout or because they are not ready to deal with |
| 2509 | * all cases correctly. The latter will be fixed (taking this sort of |
| 2510 | * stuff into VFS), but the former is not going away. Solution: the same |
| 2511 | * trick as in rmdir(). |
| 2512 | * e) conversion from fhandle to dentry may come in the wrong moment - when |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2513 | * we are removing the target. Solution: we will have to grab ->i_mutex |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2514 | * in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2515 | * ->i_mutex on parents, which works but leads to some truely excessive |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2516 | * locking]. |
| 2517 | */ |
Adrian Bunk | 75c96f8 | 2005-05-05 16:16:09 -0700 | [diff] [blame] | 2518 | static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, |
| 2519 | struct inode *new_dir, struct dentry *new_dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2520 | { |
| 2521 | int error = 0; |
| 2522 | struct inode *target; |
| 2523 | |
| 2524 | /* |
| 2525 | * If we are going to change the parent - check write permissions, |
| 2526 | * we'll need to flip '..'. |
| 2527 | */ |
| 2528 | if (new_dir != old_dir) { |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 2529 | error = inode_permission(old_dentry->d_inode, MAY_WRITE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2530 | if (error) |
| 2531 | return error; |
| 2532 | } |
| 2533 | |
| 2534 | error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry); |
| 2535 | if (error) |
| 2536 | return error; |
| 2537 | |
| 2538 | target = new_dentry->d_inode; |
| 2539 | if (target) { |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2540 | mutex_lock(&target->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2541 | dentry_unhash(new_dentry); |
| 2542 | } |
| 2543 | if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) |
| 2544 | error = -EBUSY; |
| 2545 | else |
| 2546 | error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); |
| 2547 | if (target) { |
| 2548 | if (!error) |
| 2549 | target->i_flags |= S_DEAD; |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2550 | mutex_unlock(&target->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2551 | if (d_unhashed(new_dentry)) |
| 2552 | d_rehash(new_dentry); |
| 2553 | dput(new_dentry); |
| 2554 | } |
Stephen Smalley | e31e14e | 2005-09-09 13:01:45 -0700 | [diff] [blame] | 2555 | if (!error) |
Mark Fasheh | 349457c | 2006-09-08 14:22:21 -0700 | [diff] [blame] | 2556 | if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) |
| 2557 | d_move(old_dentry,new_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2558 | return error; |
| 2559 | } |
| 2560 | |
Adrian Bunk | 75c96f8 | 2005-05-05 16:16:09 -0700 | [diff] [blame] | 2561 | static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, |
| 2562 | struct inode *new_dir, struct dentry *new_dentry) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2563 | { |
| 2564 | struct inode *target; |
| 2565 | int error; |
| 2566 | |
| 2567 | error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry); |
| 2568 | if (error) |
| 2569 | return error; |
| 2570 | |
| 2571 | dget(new_dentry); |
| 2572 | target = new_dentry->d_inode; |
| 2573 | if (target) |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2574 | mutex_lock(&target->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2575 | if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) |
| 2576 | error = -EBUSY; |
| 2577 | else |
| 2578 | error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); |
| 2579 | if (!error) { |
Mark Fasheh | 349457c | 2006-09-08 14:22:21 -0700 | [diff] [blame] | 2580 | if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2581 | d_move(old_dentry, new_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2582 | } |
| 2583 | if (target) |
Jes Sorensen | 1b1dcc1 | 2006-01-09 15:59:24 -0800 | [diff] [blame] | 2584 | mutex_unlock(&target->i_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2585 | dput(new_dentry); |
| 2586 | return error; |
| 2587 | } |
| 2588 | |
| 2589 | int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, |
| 2590 | struct inode *new_dir, struct dentry *new_dentry) |
| 2591 | { |
| 2592 | int error; |
| 2593 | int is_dir = S_ISDIR(old_dentry->d_inode->i_mode); |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 2594 | const char *old_name; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2595 | |
| 2596 | if (old_dentry->d_inode == new_dentry->d_inode) |
| 2597 | return 0; |
| 2598 | |
| 2599 | error = may_delete(old_dir, old_dentry, is_dir); |
| 2600 | if (error) |
| 2601 | return error; |
| 2602 | |
| 2603 | if (!new_dentry->d_inode) |
Miklos Szeredi | a95164d | 2008-07-30 15:08:48 +0200 | [diff] [blame] | 2604 | error = may_create(new_dir, new_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2605 | else |
| 2606 | error = may_delete(new_dir, new_dentry, is_dir); |
| 2607 | if (error) |
| 2608 | return error; |
| 2609 | |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 2610 | if (!old_dir->i_op->rename) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2611 | return -EPERM; |
| 2612 | |
Jan Kara | 9e3509e | 2009-01-26 16:45:12 +0100 | [diff] [blame] | 2613 | vfs_dq_init(old_dir); |
| 2614 | vfs_dq_init(new_dir); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2615 | |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 2616 | old_name = fsnotify_oldname_init(old_dentry->d_name.name); |
| 2617 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2618 | if (is_dir) |
| 2619 | error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry); |
| 2620 | else |
| 2621 | error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry); |
| 2622 | if (!error) { |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 2623 | const char *new_name = old_dentry->d_name.name; |
John McCutchan | 89204c4 | 2005-08-15 12:13:28 -0400 | [diff] [blame] | 2624 | fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir, |
Al Viro | 5a190ae | 2007-06-07 12:19:32 -0400 | [diff] [blame] | 2625 | new_dentry->d_inode, old_dentry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2626 | } |
Robert Love | 0eeca28 | 2005-07-12 17:06:03 -0400 | [diff] [blame] | 2627 | fsnotify_oldname_free(old_name); |
| 2628 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2629 | return error; |
| 2630 | } |
| 2631 | |
Heiko Carstens | 2e4d092 | 2009-01-14 14:14:31 +0100 | [diff] [blame] | 2632 | SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, |
| 2633 | int, newdfd, const char __user *, newname) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2634 | { |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2635 | struct dentry *old_dir, *new_dir; |
| 2636 | struct dentry *old_dentry, *new_dentry; |
| 2637 | struct dentry *trap; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2638 | struct nameidata oldnd, newnd; |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2639 | char *from; |
| 2640 | char *to; |
| 2641 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2642 | |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2643 | error = user_path_parent(olddfd, oldname, &oldnd, &from); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2644 | if (error) |
| 2645 | goto exit; |
| 2646 | |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2647 | error = user_path_parent(newdfd, newname, &newnd, &to); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2648 | if (error) |
| 2649 | goto exit1; |
| 2650 | |
| 2651 | error = -EXDEV; |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2652 | if (oldnd.path.mnt != newnd.path.mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2653 | goto exit2; |
| 2654 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2655 | old_dir = oldnd.path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2656 | error = -EBUSY; |
| 2657 | if (oldnd.last_type != LAST_NORM) |
| 2658 | goto exit2; |
| 2659 | |
Jan Blunck | 4ac9137 | 2008-02-14 19:34:32 -0800 | [diff] [blame] | 2660 | new_dir = newnd.path.dentry; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2661 | if (newnd.last_type != LAST_NORM) |
| 2662 | goto exit2; |
| 2663 | |
OGAWA Hirofumi | 0612d9f | 2008-10-16 07:50:29 +0900 | [diff] [blame] | 2664 | oldnd.flags &= ~LOOKUP_PARENT; |
| 2665 | newnd.flags &= ~LOOKUP_PARENT; |
OGAWA Hirofumi | 4e9ed2f | 2008-10-16 07:50:29 +0900 | [diff] [blame] | 2666 | newnd.flags |= LOOKUP_RENAME_TARGET; |
OGAWA Hirofumi | 0612d9f | 2008-10-16 07:50:29 +0900 | [diff] [blame] | 2667 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2668 | trap = lock_rename(new_dir, old_dir); |
| 2669 | |
Christoph Hellwig | 49705b7 | 2005-11-08 21:35:06 -0800 | [diff] [blame] | 2670 | old_dentry = lookup_hash(&oldnd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2671 | error = PTR_ERR(old_dentry); |
| 2672 | if (IS_ERR(old_dentry)) |
| 2673 | goto exit3; |
| 2674 | /* source must exist */ |
| 2675 | error = -ENOENT; |
| 2676 | if (!old_dentry->d_inode) |
| 2677 | goto exit4; |
| 2678 | /* unless the source is a directory trailing slashes give -ENOTDIR */ |
| 2679 | if (!S_ISDIR(old_dentry->d_inode->i_mode)) { |
| 2680 | error = -ENOTDIR; |
| 2681 | if (oldnd.last.name[oldnd.last.len]) |
| 2682 | goto exit4; |
| 2683 | if (newnd.last.name[newnd.last.len]) |
| 2684 | goto exit4; |
| 2685 | } |
| 2686 | /* source should not be ancestor of target */ |
| 2687 | error = -EINVAL; |
| 2688 | if (old_dentry == trap) |
| 2689 | goto exit4; |
Christoph Hellwig | 49705b7 | 2005-11-08 21:35:06 -0800 | [diff] [blame] | 2690 | new_dentry = lookup_hash(&newnd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2691 | error = PTR_ERR(new_dentry); |
| 2692 | if (IS_ERR(new_dentry)) |
| 2693 | goto exit4; |
| 2694 | /* target should not be an ancestor of source */ |
| 2695 | error = -ENOTEMPTY; |
| 2696 | if (new_dentry == trap) |
| 2697 | goto exit5; |
| 2698 | |
Dave Hansen | 9079b1e | 2008-02-15 14:37:49 -0800 | [diff] [blame] | 2699 | error = mnt_want_write(oldnd.path.mnt); |
| 2700 | if (error) |
| 2701 | goto exit5; |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2702 | error = security_path_rename(&oldnd.path, old_dentry, |
| 2703 | &newnd.path, new_dentry); |
| 2704 | if (error) |
| 2705 | goto exit6; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2706 | error = vfs_rename(old_dir->d_inode, old_dentry, |
| 2707 | new_dir->d_inode, new_dentry); |
Kentaro Takeda | be6d3e5 | 2008-12-17 13:24:15 +0900 | [diff] [blame] | 2708 | exit6: |
Dave Hansen | 9079b1e | 2008-02-15 14:37:49 -0800 | [diff] [blame] | 2709 | mnt_drop_write(oldnd.path.mnt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2710 | exit5: |
| 2711 | dput(new_dentry); |
| 2712 | exit4: |
| 2713 | dput(old_dentry); |
| 2714 | exit3: |
| 2715 | unlock_rename(new_dir, old_dir); |
| 2716 | exit2: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 2717 | path_put(&newnd.path); |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2718 | putname(to); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2719 | exit1: |
Jan Blunck | 1d957f9 | 2008-02-14 19:34:35 -0800 | [diff] [blame] | 2720 | path_put(&oldnd.path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2721 | putname(from); |
Al Viro | 2ad94ae | 2008-07-21 09:32:51 -0400 | [diff] [blame] | 2722 | exit: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2723 | return error; |
| 2724 | } |
| 2725 | |
Heiko Carstens | a26eab2 | 2009-01-14 14:14:17 +0100 | [diff] [blame] | 2726 | SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname) |
Ulrich Drepper | 5590ff0 | 2006-01-18 17:43:53 -0800 | [diff] [blame] | 2727 | { |
| 2728 | return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname); |
| 2729 | } |
| 2730 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2731 | int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const char *link) |
| 2732 | { |
| 2733 | int len; |
| 2734 | |
| 2735 | len = PTR_ERR(link); |
| 2736 | if (IS_ERR(link)) |
| 2737 | goto out; |
| 2738 | |
| 2739 | len = strlen(link); |
| 2740 | if (len > (unsigned) buflen) |
| 2741 | len = buflen; |
| 2742 | if (copy_to_user(buffer, link, len)) |
| 2743 | len = -EFAULT; |
| 2744 | out: |
| 2745 | return len; |
| 2746 | } |
| 2747 | |
| 2748 | /* |
| 2749 | * A helper for ->readlink(). This should be used *ONLY* for symlinks that |
| 2750 | * have ->follow_link() touching nd only in nd_set_link(). Using (or not |
| 2751 | * using) it for any given inode is up to filesystem. |
| 2752 | */ |
| 2753 | int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen) |
| 2754 | { |
| 2755 | struct nameidata nd; |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2756 | void *cookie; |
Marcin Slusarz | 694a176 | 2008-06-09 16:40:37 -0700 | [diff] [blame] | 2757 | int res; |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2758 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2759 | nd.depth = 0; |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2760 | cookie = dentry->d_inode->i_op->follow_link(dentry, &nd); |
Marcin Slusarz | 694a176 | 2008-06-09 16:40:37 -0700 | [diff] [blame] | 2761 | if (IS_ERR(cookie)) |
| 2762 | return PTR_ERR(cookie); |
| 2763 | |
| 2764 | res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd)); |
| 2765 | if (dentry->d_inode->i_op->put_link) |
| 2766 | dentry->d_inode->i_op->put_link(dentry, &nd, cookie); |
| 2767 | return res; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2768 | } |
| 2769 | |
| 2770 | int vfs_follow_link(struct nameidata *nd, const char *link) |
| 2771 | { |
| 2772 | return __vfs_follow_link(nd, link); |
| 2773 | } |
| 2774 | |
| 2775 | /* get the link contents into pagecache */ |
| 2776 | static char *page_getlink(struct dentry * dentry, struct page **ppage) |
| 2777 | { |
Duane Griffin | ebd09ab | 2008-12-19 20:47:12 +0000 | [diff] [blame] | 2778 | char *kaddr; |
| 2779 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2780 | struct address_space *mapping = dentry->d_inode->i_mapping; |
Pekka Enberg | 090d2b1 | 2006-06-23 02:05:08 -0700 | [diff] [blame] | 2781 | page = read_mapping_page(mapping, 0, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2782 | if (IS_ERR(page)) |
Nick Piggin | 6fe6900 | 2007-05-06 14:49:04 -0700 | [diff] [blame] | 2783 | return (char*)page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2784 | *ppage = page; |
Duane Griffin | ebd09ab | 2008-12-19 20:47:12 +0000 | [diff] [blame] | 2785 | kaddr = kmap(page); |
| 2786 | nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1); |
| 2787 | return kaddr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2788 | } |
| 2789 | |
| 2790 | int page_readlink(struct dentry *dentry, char __user *buffer, int buflen) |
| 2791 | { |
| 2792 | struct page *page = NULL; |
| 2793 | char *s = page_getlink(dentry, &page); |
| 2794 | int res = vfs_readlink(dentry,buffer,buflen,s); |
| 2795 | if (page) { |
| 2796 | kunmap(page); |
| 2797 | page_cache_release(page); |
| 2798 | } |
| 2799 | return res; |
| 2800 | } |
| 2801 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2802 | void *page_follow_link_light(struct dentry *dentry, struct nameidata *nd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2803 | { |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2804 | struct page *page = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2805 | nd_set_link(nd, page_getlink(dentry, &page)); |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2806 | return page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2807 | } |
| 2808 | |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2809 | void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2810 | { |
Linus Torvalds | cc314ee | 2005-08-19 18:02:56 -0700 | [diff] [blame] | 2811 | struct page *page = cookie; |
| 2812 | |
| 2813 | if (page) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2814 | kunmap(page); |
| 2815 | page_cache_release(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2816 | } |
| 2817 | } |
| 2818 | |
Nick Piggin | 54566b2 | 2009-01-04 12:00:53 -0800 | [diff] [blame] | 2819 | /* |
| 2820 | * The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS |
| 2821 | */ |
| 2822 | int __page_symlink(struct inode *inode, const char *symname, int len, int nofs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2823 | { |
| 2824 | struct address_space *mapping = inode->i_mapping; |
Kirill Korotaev | 0adb25d | 2006-03-11 03:27:13 -0800 | [diff] [blame] | 2825 | struct page *page; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2826 | void *fsdata; |
Dmitriy Monakhov | beb497a | 2007-02-16 01:27:18 -0800 | [diff] [blame] | 2827 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2828 | char *kaddr; |
Nick Piggin | 54566b2 | 2009-01-04 12:00:53 -0800 | [diff] [blame] | 2829 | unsigned int flags = AOP_FLAG_UNINTERRUPTIBLE; |
| 2830 | if (nofs) |
| 2831 | flags |= AOP_FLAG_NOFS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2832 | |
NeilBrown | 7e53cac | 2006-03-25 03:07:57 -0800 | [diff] [blame] | 2833 | retry: |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2834 | err = pagecache_write_begin(NULL, mapping, 0, len-1, |
Nick Piggin | 54566b2 | 2009-01-04 12:00:53 -0800 | [diff] [blame] | 2835 | flags, &page, &fsdata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2836 | if (err) |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2837 | goto fail; |
| 2838 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2839 | kaddr = kmap_atomic(page, KM_USER0); |
| 2840 | memcpy(kaddr, symname, len-1); |
| 2841 | kunmap_atomic(kaddr, KM_USER0); |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2842 | |
| 2843 | err = pagecache_write_end(NULL, mapping, 0, len-1, len-1, |
| 2844 | page, fsdata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2845 | if (err < 0) |
| 2846 | goto fail; |
Nick Piggin | afddba4 | 2007-10-16 01:25:01 -0700 | [diff] [blame] | 2847 | if (err < len-1) |
| 2848 | goto retry; |
| 2849 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2850 | mark_inode_dirty(inode); |
| 2851 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2852 | fail: |
| 2853 | return err; |
| 2854 | } |
| 2855 | |
Kirill Korotaev | 0adb25d | 2006-03-11 03:27:13 -0800 | [diff] [blame] | 2856 | int page_symlink(struct inode *inode, const char *symname, int len) |
| 2857 | { |
| 2858 | return __page_symlink(inode, symname, len, |
Nick Piggin | 54566b2 | 2009-01-04 12:00:53 -0800 | [diff] [blame] | 2859 | !(mapping_gfp_mask(inode->i_mapping) & __GFP_FS)); |
Kirill Korotaev | 0adb25d | 2006-03-11 03:27:13 -0800 | [diff] [blame] | 2860 | } |
| 2861 | |
Arjan van de Ven | 92e1d5b | 2007-02-12 00:55:39 -0800 | [diff] [blame] | 2862 | const struct inode_operations page_symlink_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2863 | .readlink = generic_readlink, |
| 2864 | .follow_link = page_follow_link_light, |
| 2865 | .put_link = page_put_link, |
| 2866 | }; |
| 2867 | |
Al Viro | 2d8f303 | 2008-07-22 09:59:21 -0400 | [diff] [blame] | 2868 | EXPORT_SYMBOL(user_path_at); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2869 | EXPORT_SYMBOL(follow_down); |
| 2870 | EXPORT_SYMBOL(follow_up); |
| 2871 | EXPORT_SYMBOL(get_write_access); /* binfmt_aout */ |
| 2872 | EXPORT_SYMBOL(getname); |
| 2873 | EXPORT_SYMBOL(lock_rename); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2874 | EXPORT_SYMBOL(lookup_one_len); |
| 2875 | EXPORT_SYMBOL(page_follow_link_light); |
| 2876 | EXPORT_SYMBOL(page_put_link); |
| 2877 | EXPORT_SYMBOL(page_readlink); |
Kirill Korotaev | 0adb25d | 2006-03-11 03:27:13 -0800 | [diff] [blame] | 2878 | EXPORT_SYMBOL(__page_symlink); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2879 | EXPORT_SYMBOL(page_symlink); |
| 2880 | EXPORT_SYMBOL(page_symlink_inode_operations); |
| 2881 | EXPORT_SYMBOL(path_lookup); |
Al Viro | d181146 | 2008-08-02 00:49:18 -0400 | [diff] [blame] | 2882 | EXPORT_SYMBOL(kern_path); |
Josef 'Jeff' Sipek | 16f1820 | 2007-07-19 01:48:18 -0700 | [diff] [blame] | 2883 | EXPORT_SYMBOL(vfs_path_lookup); |
Al Viro | f419a2e | 2008-07-22 00:07:17 -0400 | [diff] [blame] | 2884 | EXPORT_SYMBOL(inode_permission); |
Christoph Hellwig | 8c744fb | 2005-11-08 21:35:04 -0800 | [diff] [blame] | 2885 | EXPORT_SYMBOL(file_permission); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2886 | EXPORT_SYMBOL(unlock_rename); |
| 2887 | EXPORT_SYMBOL(vfs_create); |
| 2888 | EXPORT_SYMBOL(vfs_follow_link); |
| 2889 | EXPORT_SYMBOL(vfs_link); |
| 2890 | EXPORT_SYMBOL(vfs_mkdir); |
| 2891 | EXPORT_SYMBOL(vfs_mknod); |
| 2892 | EXPORT_SYMBOL(generic_permission); |
| 2893 | EXPORT_SYMBOL(vfs_readlink); |
| 2894 | EXPORT_SYMBOL(vfs_rename); |
| 2895 | EXPORT_SYMBOL(vfs_rmdir); |
| 2896 | EXPORT_SYMBOL(vfs_symlink); |
| 2897 | EXPORT_SYMBOL(vfs_unlink); |
| 2898 | EXPORT_SYMBOL(dentry_unhash); |
| 2899 | EXPORT_SYMBOL(generic_readlink); |
Al Viro | 18d8fda | 2008-12-26 00:35:37 -0500 | [diff] [blame] | 2900 | |
| 2901 | /* to be mentioned only in INIT_TASK */ |
| 2902 | struct fs_struct init_fs = { |
| 2903 | .count = ATOMIC_INIT(1), |
Steven Rostedt | 1239f26 | 2008-12-10 18:37:28 -0500 | [diff] [blame] | 2904 | .lock = __RW_LOCK_UNLOCKED(init_fs.lock), |
Al Viro | 18d8fda | 2008-12-26 00:35:37 -0500 | [diff] [blame] | 2905 | .umask = 0022, |
| 2906 | }; |