Commit | Line | Data |
---|---|---|
e9a7c2f1 IK |
1 | /* |
2 | * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved | |
3 | * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> | |
4 | * Copyright 2001-2006 Ian Kent <raven@themaw.net> | |
1da177e4 LT |
5 | * |
6 | * This file is part of the Linux kernel and is made available under | |
7 | * the terms of the GNU General Public License, version 2, or at your | |
8 | * option, any later version, incorporated herein by reference. | |
e9a7c2f1 | 9 | */ |
1da177e4 | 10 | |
16f7e0fe | 11 | #include <linux/capability.h> |
1da177e4 LT |
12 | #include <linux/errno.h> |
13 | #include <linux/stat.h> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
1da177e4 LT |
15 | #include <linux/param.h> |
16 | #include <linux/time.h> | |
c9243f5b | 17 | #include <linux/compat.h> |
00e300e1 | 18 | #include <linux/mutex.h> |
c9243f5b | 19 | |
1da177e4 LT |
20 | #include "autofs_i.h" |
21 | ||
e9a7c2f1 IK |
22 | static int autofs4_dir_symlink(struct inode *, struct dentry *, const char *); |
23 | static int autofs4_dir_unlink(struct inode *, struct dentry *); | |
24 | static int autofs4_dir_rmdir(struct inode *, struct dentry *); | |
25 | static int autofs4_dir_mkdir(struct inode *, struct dentry *, umode_t); | |
26 | static long autofs4_root_ioctl(struct file *, unsigned int, unsigned long); | |
5a44a73b | 27 | #ifdef CONFIG_COMPAT |
e9a7c2f1 IK |
28 | static long autofs4_root_compat_ioctl(struct file *, |
29 | unsigned int, unsigned long); | |
5a44a73b | 30 | #endif |
1da177e4 | 31 | static int autofs4_dir_open(struct inode *inode, struct file *file); |
e9a7c2f1 IK |
32 | static struct dentry *autofs4_lookup(struct inode *, |
33 | struct dentry *, unsigned int); | |
71e469db | 34 | static struct vfsmount *autofs4_d_automount(struct path *); |
fb5f51c7 | 35 | static int autofs4_d_manage(const struct path *, bool); |
b89b12b4 | 36 | static void autofs4_dentry_release(struct dentry *); |
1da177e4 | 37 | |
4b6f5d20 | 38 | const struct file_operations autofs4_root_operations = { |
1da177e4 LT |
39 | .open = dcache_dir_open, |
40 | .release = dcache_dir_close, | |
41 | .read = generic_read_dir, | |
4e82901c | 42 | .iterate_shared = dcache_readdir, |
59af1584 | 43 | .llseek = dcache_dir_lseek, |
3663df70 | 44 | .unlocked_ioctl = autofs4_root_ioctl, |
c9243f5b AB |
45 | #ifdef CONFIG_COMPAT |
46 | .compat_ioctl = autofs4_root_compat_ioctl, | |
47 | #endif | |
1da177e4 LT |
48 | }; |
49 | ||
4b6f5d20 | 50 | const struct file_operations autofs4_dir_operations = { |
1da177e4 | 51 | .open = autofs4_dir_open, |
ff9cd499 | 52 | .release = dcache_dir_close, |
1da177e4 | 53 | .read = generic_read_dir, |
4e82901c | 54 | .iterate_shared = dcache_readdir, |
59af1584 | 55 | .llseek = dcache_dir_lseek, |
1da177e4 LT |
56 | }; |
57 | ||
754661f1 | 58 | const struct inode_operations autofs4_dir_inode_operations = { |
1da177e4 LT |
59 | .lookup = autofs4_lookup, |
60 | .unlink = autofs4_dir_unlink, | |
61 | .symlink = autofs4_dir_symlink, | |
62 | .mkdir = autofs4_dir_mkdir, | |
63 | .rmdir = autofs4_dir_rmdir, | |
64 | }; | |
65 | ||
71e469db | 66 | const struct dentry_operations autofs4_dentry_operations = { |
71e469db IK |
67 | .d_automount = autofs4_d_automount, |
68 | .d_manage = autofs4_d_manage, | |
69 | .d_release = autofs4_dentry_release, | |
70 | }; | |
71 | ||
4f8427d1 IK |
72 | static void autofs4_add_active(struct dentry *dentry) |
73 | { | |
74 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
e9a7c2f1 IK |
75 | struct autofs_info *ino; |
76 | ||
77 | ino = autofs4_dentry_ino(dentry); | |
4f8427d1 IK |
78 | if (ino) { |
79 | spin_lock(&sbi->lookup_lock); | |
80 | if (!ino->active_count) { | |
81 | if (list_empty(&ino->active)) | |
82 | list_add(&ino->active, &sbi->active_list); | |
83 | } | |
84 | ino->active_count++; | |
85 | spin_unlock(&sbi->lookup_lock); | |
86 | } | |
4f8427d1 IK |
87 | } |
88 | ||
89 | static void autofs4_del_active(struct dentry *dentry) | |
90 | { | |
91 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
e9a7c2f1 IK |
92 | struct autofs_info *ino; |
93 | ||
94 | ino = autofs4_dentry_ino(dentry); | |
4f8427d1 IK |
95 | if (ino) { |
96 | spin_lock(&sbi->lookup_lock); | |
97 | ino->active_count--; | |
98 | if (!ino->active_count) { | |
99 | if (!list_empty(&ino->active)) | |
100 | list_del_init(&ino->active); | |
101 | } | |
102 | spin_unlock(&sbi->lookup_lock); | |
103 | } | |
4f8427d1 IK |
104 | } |
105 | ||
1da177e4 LT |
106 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
107 | { | |
a4669ed8 | 108 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 109 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 110 | |
8a78d593 | 111 | pr_debug("file=%p dentry=%p %pd\n", file, dentry, dentry); |
1da177e4 LT |
112 | |
113 | if (autofs4_oz_mode(sbi)) | |
114 | goto out; | |
115 | ||
ff9cd499 IK |
116 | /* |
117 | * An empty directory in an autofs file system is always a | |
118 | * mount point. The daemon must have failed to mount this | |
119 | * during lookup so it doesn't exist. This can happen, for | |
120 | * example, if user space returns an incorrect status for a | |
121 | * mount request. Otherwise we're doing a readdir on the | |
122 | * autofs file system so just let the libfs routines handle | |
123 | * it. | |
124 | */ | |
e7854723 | 125 | spin_lock(&sbi->lookup_lock); |
cfaf86ab | 126 | if (!path_is_mountpoint(&file->f_path) && simple_empty(dentry)) { |
e7854723 | 127 | spin_unlock(&sbi->lookup_lock); |
ff9cd499 | 128 | return -ENOENT; |
1da177e4 | 129 | } |
e7854723 | 130 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 131 | |
1da177e4 | 132 | out: |
ff9cd499 | 133 | return dcache_dir_open(inode, file); |
1da177e4 LT |
134 | } |
135 | ||
b89b12b4 | 136 | static void autofs4_dentry_release(struct dentry *de) |
1da177e4 | 137 | { |
b89b12b4 AV |
138 | struct autofs_info *ino = autofs4_dentry_ino(de); |
139 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); | |
1da177e4 | 140 | |
8a78d593 | 141 | pr_debug("releasing %p\n", de); |
1da177e4 | 142 | |
b89b12b4 AV |
143 | if (!ino) |
144 | return; | |
145 | ||
146 | if (sbi) { | |
147 | spin_lock(&sbi->lookup_lock); | |
148 | if (!list_empty(&ino->active)) | |
149 | list_del(&ino->active); | |
150 | if (!list_empty(&ino->expiring)) | |
151 | list_del(&ino->expiring); | |
152 | spin_unlock(&sbi->lookup_lock); | |
1da177e4 | 153 | } |
b89b12b4 AV |
154 | |
155 | autofs4_free_ino(ino); | |
1da177e4 LT |
156 | } |
157 | ||
6510c9d8 | 158 | static struct dentry *autofs4_lookup_active(struct dentry *dentry) |
25767378 | 159 | { |
6510c9d8 IK |
160 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
161 | struct dentry *parent = dentry->d_parent; | |
8ac790f3 | 162 | const struct qstr *name = &dentry->d_name; |
25767378 IK |
163 | unsigned int len = name->len; |
164 | unsigned int hash = name->hash; | |
165 | const unsigned char *str = name->name; | |
166 | struct list_head *p, *head; | |
167 | ||
25767378 | 168 | head = &sbi->active_list; |
668128e9 N |
169 | if (list_empty(head)) |
170 | return NULL; | |
171 | spin_lock(&sbi->lookup_lock); | |
25767378 IK |
172 | list_for_each(p, head) { |
173 | struct autofs_info *ino; | |
e4d5ade7 | 174 | struct dentry *active; |
8ac790f3 | 175 | const struct qstr *qstr; |
25767378 IK |
176 | |
177 | ino = list_entry(p, struct autofs_info, active); | |
e4d5ade7 | 178 | active = ino->dentry; |
25767378 | 179 | |
e4d5ade7 | 180 | spin_lock(&active->d_lock); |
25767378 IK |
181 | |
182 | /* Already gone? */ | |
6b6751f7 | 183 | if ((int) d_count(active) <= 0) |
25767378 IK |
184 | goto next; |
185 | ||
e4d5ade7 | 186 | qstr = &active->d_name; |
25767378 | 187 | |
e4d5ade7 | 188 | if (active->d_name.hash != hash) |
25767378 | 189 | goto next; |
e4d5ade7 | 190 | if (active->d_parent != parent) |
25767378 IK |
191 | goto next; |
192 | ||
193 | if (qstr->len != len) | |
194 | goto next; | |
195 | if (memcmp(qstr->name, str, len)) | |
196 | goto next; | |
197 | ||
4b1ae27a | 198 | if (d_unhashed(active)) { |
b7ab39f6 | 199 | dget_dlock(active); |
4b1ae27a AV |
200 | spin_unlock(&active->d_lock); |
201 | spin_unlock(&sbi->lookup_lock); | |
4b1ae27a AV |
202 | return active; |
203 | } | |
25767378 | 204 | next: |
e4d5ade7 | 205 | spin_unlock(&active->d_lock); |
25767378 IK |
206 | } |
207 | spin_unlock(&sbi->lookup_lock); | |
25767378 IK |
208 | |
209 | return NULL; | |
210 | } | |
211 | ||
23bfc2a2 N |
212 | static struct dentry *autofs4_lookup_expiring(struct dentry *dentry, |
213 | bool rcu_walk) | |
f50b6f86 | 214 | { |
6510c9d8 IK |
215 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
216 | struct dentry *parent = dentry->d_parent; | |
8ac790f3 | 217 | const struct qstr *name = &dentry->d_name; |
f50b6f86 IK |
218 | unsigned int len = name->len; |
219 | unsigned int hash = name->hash; | |
220 | const unsigned char *str = name->name; | |
221 | struct list_head *p, *head; | |
222 | ||
5f6f4f28 | 223 | head = &sbi->expiring_list; |
668128e9 N |
224 | if (list_empty(head)) |
225 | return NULL; | |
226 | spin_lock(&sbi->lookup_lock); | |
f50b6f86 IK |
227 | list_for_each(p, head) { |
228 | struct autofs_info *ino; | |
cb4b492a | 229 | struct dentry *expiring; |
8ac790f3 | 230 | const struct qstr *qstr; |
f50b6f86 | 231 | |
23bfc2a2 N |
232 | if (rcu_walk) { |
233 | spin_unlock(&sbi->lookup_lock); | |
234 | return ERR_PTR(-ECHILD); | |
235 | } | |
236 | ||
5f6f4f28 | 237 | ino = list_entry(p, struct autofs_info, expiring); |
cb4b492a | 238 | expiring = ino->dentry; |
f50b6f86 | 239 | |
cb4b492a | 240 | spin_lock(&expiring->d_lock); |
f50b6f86 | 241 | |
6b6751f7 | 242 | /* We've already been dentry_iput or unlinked */ |
2b0143b5 | 243 | if (d_really_is_negative(expiring)) |
f50b6f86 IK |
244 | goto next; |
245 | ||
cb4b492a | 246 | qstr = &expiring->d_name; |
f50b6f86 | 247 | |
cb4b492a | 248 | if (expiring->d_name.hash != hash) |
f50b6f86 | 249 | goto next; |
cb4b492a | 250 | if (expiring->d_parent != parent) |
f50b6f86 IK |
251 | goto next; |
252 | ||
253 | if (qstr->len != len) | |
254 | goto next; | |
255 | if (memcmp(qstr->name, str, len)) | |
256 | goto next; | |
257 | ||
4b1ae27a | 258 | if (d_unhashed(expiring)) { |
b7ab39f6 | 259 | dget_dlock(expiring); |
4b1ae27a AV |
260 | spin_unlock(&expiring->d_lock); |
261 | spin_unlock(&sbi->lookup_lock); | |
4b1ae27a AV |
262 | return expiring; |
263 | } | |
f50b6f86 | 264 | next: |
cb4b492a | 265 | spin_unlock(&expiring->d_lock); |
f50b6f86 | 266 | } |
5f6f4f28 | 267 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
268 | |
269 | return NULL; | |
270 | } | |
271 | ||
dd36a882 | 272 | static int autofs4_mount_wait(const struct path *path, bool rcu_walk) |
10584211 | 273 | { |
dd36a882 IK |
274 | struct autofs_sb_info *sbi = autofs4_sbi(path->dentry->d_sb); |
275 | struct autofs_info *ino = autofs4_dentry_ino(path->dentry); | |
3c319985 | 276 | int status = 0; |
10584211 IK |
277 | |
278 | if (ino->flags & AUTOFS_INF_PENDING) { | |
23bfc2a2 N |
279 | if (rcu_walk) |
280 | return -ECHILD; | |
dd36a882 IK |
281 | pr_debug("waiting for mount name=%pd\n", path->dentry); |
282 | status = autofs4_wait(sbi, path, NFY_MOUNT); | |
8a78d593 | 283 | pr_debug("mount wait done status=%d\n", status); |
092a5345 | 284 | ino->last_used = jiffies; |
10584211 | 285 | } |
3c319985 | 286 | return status; |
10584211 IK |
287 | } |
288 | ||
74f504cf | 289 | static int do_expire_wait(const struct path *path, bool rcu_walk) |
10584211 | 290 | { |
74f504cf | 291 | struct dentry *dentry = path->dentry; |
10584211 IK |
292 | struct dentry *expiring; |
293 | ||
23bfc2a2 N |
294 | expiring = autofs4_lookup_expiring(dentry, rcu_walk); |
295 | if (IS_ERR(expiring)) | |
296 | return PTR_ERR(expiring); | |
10584211 | 297 | if (!expiring) |
74f504cf | 298 | return autofs4_expire_wait(path, rcu_walk); |
10584211 | 299 | else { |
455e8f10 | 300 | const struct path this = { .mnt = path->mnt, .dentry = expiring }; |
10584211 IK |
301 | /* |
302 | * If we are racing with expire the request might not | |
303 | * be quite complete, but the directory has been removed | |
304 | * so it must have been successful, just wait for it. | |
305 | */ | |
74f504cf | 306 | autofs4_expire_wait(&this, 0); |
10584211 IK |
307 | autofs4_del_expiring(expiring); |
308 | dput(expiring); | |
309 | } | |
310 | return 0; | |
311 | } | |
312 | ||
313 | static struct dentry *autofs4_mountpoint_changed(struct path *path) | |
314 | { | |
315 | struct dentry *dentry = path->dentry; | |
316 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
317 | ||
318 | /* | |
319 | * If this is an indirect mount the dentry could have gone away | |
320 | * as a result of an expire and a new one created. | |
321 | */ | |
322 | if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { | |
323 | struct dentry *parent = dentry->d_parent; | |
e9a7c2f1 IK |
324 | struct dentry *new; |
325 | ||
326 | new = d_lookup(parent, &dentry->d_name); | |
10584211 IK |
327 | if (!new) |
328 | return NULL; | |
092a5345 IK |
329 | if (new == dentry) |
330 | dput(new); | |
331 | else { | |
332 | struct autofs_info *ino; | |
333 | ||
334 | ino = autofs4_dentry_ino(new); | |
335 | ino->last_used = jiffies; | |
336 | dput(path->dentry); | |
337 | path->dentry = new; | |
338 | } | |
10584211 IK |
339 | } |
340 | return path->dentry; | |
341 | } | |
342 | ||
71e469db | 343 | static struct vfsmount *autofs4_d_automount(struct path *path) |
10584211 IK |
344 | { |
345 | struct dentry *dentry = path->dentry; | |
346 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
347 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
348 | int status; | |
349 | ||
8a78d593 | 350 | pr_debug("dentry=%p %pd\n", dentry, dentry); |
10584211 IK |
351 | |
352 | /* The daemon never triggers a mount. */ | |
353 | if (autofs4_oz_mode(sbi)) | |
354 | return NULL; | |
355 | ||
356 | /* | |
357 | * If an expire request is pending everyone must wait. | |
358 | * If the expire fails we're still mounted so continue | |
359 | * the follow and return. A return of -EAGAIN (which only | |
360 | * happens with indirect mounts) means the expire completed | |
361 | * and the directory was removed, so just go ahead and try | |
362 | * the mount. | |
363 | */ | |
74f504cf | 364 | status = do_expire_wait(path, 0); |
10584211 IK |
365 | if (status && status != -EAGAIN) |
366 | return NULL; | |
367 | ||
368 | /* Callback to the daemon to perform the mount or wait */ | |
369 | spin_lock(&sbi->fs_lock); | |
370 | if (ino->flags & AUTOFS_INF_PENDING) { | |
371 | spin_unlock(&sbi->fs_lock); | |
dd36a882 | 372 | status = autofs4_mount_wait(path, 0); |
10584211 IK |
373 | if (status) |
374 | return ERR_PTR(status); | |
10584211 IK |
375 | goto done; |
376 | } | |
377 | ||
378 | /* | |
379 | * If the dentry is a symlink it's equivalent to a directory | |
cfaf86ab IK |
380 | * having path_is_mountpoint() true, so there's no need to call |
381 | * back to the daemon. | |
10584211 | 382 | */ |
2b0143b5 | 383 | if (d_really_is_positive(dentry) && d_is_symlink(dentry)) { |
f55fb0c2 | 384 | spin_unlock(&sbi->fs_lock); |
10584211 | 385 | goto done; |
f55fb0c2 IK |
386 | } |
387 | ||
cfaf86ab | 388 | if (!path_is_mountpoint(path)) { |
b5b80177 IK |
389 | /* |
390 | * It's possible that user space hasn't removed directories | |
391 | * after umounting a rootless multi-mount, although it | |
60359741 IK |
392 | * should. For v5 path_has_submounts() is sufficient to |
393 | * handle this because the leaves of the directory tree under | |
394 | * the mount never trigger mounts themselves (they have an | |
395 | * autofs trigger mount mounted on them). But v4 pseudo direct | |
396 | * mounts do need the leaves to trigger mounts. In this case | |
397 | * we have no choice but to use the list_empty() check and | |
b5b80177 IK |
398 | * require user space behave. |
399 | */ | |
400 | if (sbi->version > 4) { | |
60359741 | 401 | if (path_has_submounts(path)) { |
f55fb0c2 | 402 | spin_unlock(&sbi->fs_lock); |
b5b80177 | 403 | goto done; |
f55fb0c2 | 404 | } |
b5b80177 | 405 | } else { |
9d8072e7 PH |
406 | if (!simple_empty(dentry)) { |
407 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 408 | goto done; |
9d8072e7 | 409 | } |
b5b80177 | 410 | } |
10584211 | 411 | ino->flags |= AUTOFS_INF_PENDING; |
10584211 | 412 | spin_unlock(&sbi->fs_lock); |
dd36a882 | 413 | status = autofs4_mount_wait(path, 0); |
10584211 IK |
414 | spin_lock(&sbi->fs_lock); |
415 | ino->flags &= ~AUTOFS_INF_PENDING; | |
49999ab2 IK |
416 | if (status) { |
417 | spin_unlock(&sbi->fs_lock); | |
418 | return ERR_PTR(status); | |
419 | } | |
10584211 | 420 | } |
10584211 | 421 | spin_unlock(&sbi->fs_lock); |
f55fb0c2 | 422 | done: |
10584211 IK |
423 | /* Mount succeeded, check if we ended up with a new dentry */ |
424 | dentry = autofs4_mountpoint_changed(path); | |
425 | if (!dentry) | |
426 | return ERR_PTR(-ENOENT); | |
427 | ||
428 | return NULL; | |
429 | } | |
430 | ||
fb5f51c7 | 431 | static int autofs4_d_manage(const struct path *path, bool rcu_walk) |
b5b80177 | 432 | { |
fb5f51c7 | 433 | struct dentry *dentry = path->dentry; |
b5b80177 | 434 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f55fb0c2 IK |
435 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
436 | int status; | |
b5b80177 | 437 | |
8a78d593 | 438 | pr_debug("dentry=%p %pd\n", dentry, dentry); |
b5b80177 IK |
439 | |
440 | /* The daemon never waits. */ | |
1aed3e42 | 441 | if (autofs4_oz_mode(sbi)) { |
cfaf86ab | 442 | if (!path_is_mountpoint(path)) |
b5b80177 IK |
443 | return -EISDIR; |
444 | return 0; | |
445 | } | |
446 | ||
447 | /* Wait for pending expires */ | |
74f504cf | 448 | if (do_expire_wait(path, rcu_walk) == -ECHILD) |
23bfc2a2 | 449 | return -ECHILD; |
b5b80177 IK |
450 | |
451 | /* | |
452 | * This dentry may be under construction so wait on mount | |
453 | * completion. | |
454 | */ | |
dd36a882 | 455 | status = autofs4_mount_wait(path, rcu_walk); |
f55fb0c2 IK |
456 | if (status) |
457 | return status; | |
458 | ||
ef16cc59 N |
459 | if (rcu_walk) { |
460 | /* We don't need fs_lock in rcu_walk mode, | |
461 | * just testing 'AUTOFS_INFO_NO_RCU' is enough. | |
462 | * simple_empty() takes a spinlock, so leave it | |
463 | * to last. | |
464 | * We only return -EISDIR when certain this isn't | |
465 | * a mount-trap. | |
23bfc2a2 | 466 | */ |
ef16cc59 | 467 | struct inode *inode; |
e9a7c2f1 | 468 | |
ea01a184 | 469 | if (ino->flags & AUTOFS_INF_WANT_EXPIRE) |
ef16cc59 | 470 | return 0; |
cfaf86ab | 471 | if (path_is_mountpoint(path)) |
ef16cc59 | 472 | return 0; |
2b0143b5 | 473 | inode = d_inode_rcu(dentry); |
ef16cc59 N |
474 | if (inode && S_ISLNK(inode->i_mode)) |
475 | return -EISDIR; | |
476 | if (list_empty(&dentry->d_subdirs)) | |
477 | return 0; | |
478 | if (!simple_empty(dentry)) | |
479 | return -EISDIR; | |
23bfc2a2 | 480 | return 0; |
ef16cc59 | 481 | } |
23bfc2a2 | 482 | |
f55fb0c2 IK |
483 | spin_lock(&sbi->fs_lock); |
484 | /* | |
485 | * If the dentry has been selected for expire while we slept | |
486 | * on the lock then it might go away. We'll deal with that in | |
487 | * ->d_automount() and wait on a new mount if the expire | |
488 | * succeeds or return here if it doesn't (since there's no | |
489 | * mount to follow with a rootless multi-mount). | |
490 | */ | |
491 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { | |
492 | /* | |
493 | * Any needed mounting has been completed and the path | |
494 | * updated so check if this is a rootless multi-mount so | |
495 | * we can avoid needless calls ->d_automount() and avoid | |
496 | * an incorrect ELOOP error return. | |
497 | */ | |
cfaf86ab | 498 | if ((!path_is_mountpoint(path) && !simple_empty(dentry)) || |
2b0143b5 | 499 | (d_really_is_positive(dentry) && d_is_symlink(dentry))) |
f55fb0c2 IK |
500 | status = -EISDIR; |
501 | } | |
502 | spin_unlock(&sbi->fs_lock); | |
503 | ||
504 | return status; | |
b5b80177 IK |
505 | } |
506 | ||
1da177e4 | 507 | /* Lookups in the root directory */ |
e9a7c2f1 IK |
508 | static struct dentry *autofs4_lookup(struct inode *dir, |
509 | struct dentry *dentry, unsigned int flags) | |
1da177e4 LT |
510 | { |
511 | struct autofs_sb_info *sbi; | |
25767378 | 512 | struct autofs_info *ino; |
10584211 | 513 | struct dentry *active; |
1da177e4 | 514 | |
8a78d593 | 515 | pr_debug("name = %pd\n", dentry); |
1da177e4 | 516 | |
718c604a | 517 | /* File name too long to exist */ |
1da177e4 | 518 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 519 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
520 | |
521 | sbi = autofs4_sbi(dir->i_sb); | |
718c604a | 522 | |
8a78d593 IK |
523 | pr_debug("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n", |
524 | current->pid, task_pgrp_nr(current), sbi->catatonic, | |
525 | autofs4_oz_mode(sbi)); | |
1da177e4 | 526 | |
6510c9d8 | 527 | active = autofs4_lookup_active(dentry); |
e9a7c2f1 | 528 | if (active) |
10584211 | 529 | return active; |
e9a7c2f1 | 530 | else { |
4b1ae27a | 531 | /* |
10584211 IK |
532 | * A dentry that is not within the root can never trigger a |
533 | * mount operation, unless the directory already exists, so we | |
534 | * can return fail immediately. The daemon however does need | |
535 | * to create directories within the file system. | |
4b1ae27a | 536 | */ |
10584211 IK |
537 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
538 | return ERR_PTR(-ENOENT); | |
539 | ||
540 | /* Mark entries in the root as mount triggers */ | |
e9a7c2f1 IK |
541 | if (IS_ROOT(dentry->d_parent) && |
542 | autofs_type_indirect(sbi->type)) | |
b5b80177 | 543 | __managed_dentry_set_managed(dentry); |
10584211 | 544 | |
26e6c910 | 545 | ino = autofs4_new_ino(sbi); |
4b1ae27a AV |
546 | if (!ino) |
547 | return ERR_PTR(-ENOMEM); | |
548 | ||
549 | dentry->d_fsdata = ino; | |
550 | ino->dentry = dentry; | |
5f6f4f28 | 551 | |
4b1ae27a | 552 | autofs4_add_active(dentry); |
4b1ae27a | 553 | } |
1da177e4 LT |
554 | return NULL; |
555 | } | |
556 | ||
557 | static int autofs4_dir_symlink(struct inode *dir, | |
558 | struct dentry *dentry, | |
559 | const char *symname) | |
560 | { | |
561 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
562 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 563 | struct autofs_info *p_ino; |
1da177e4 | 564 | struct inode *inode; |
0bf71d4d | 565 | size_t size = strlen(symname); |
1da177e4 LT |
566 | char *cp; |
567 | ||
8a78d593 | 568 | pr_debug("%s <- %pd\n", symname, dentry); |
1da177e4 LT |
569 | |
570 | if (!autofs4_oz_mode(sbi)) | |
571 | return -EACCES; | |
572 | ||
5a37db30 AV |
573 | BUG_ON(!ino); |
574 | ||
26e6c910 | 575 | autofs4_clean_ino(ino); |
1da177e4 | 576 | |
4b1ae27a AV |
577 | autofs4_del_active(dentry); |
578 | ||
0bf71d4d | 579 | cp = kmalloc(size + 1, GFP_KERNEL); |
5a37db30 | 580 | if (!cp) |
25767378 | 581 | return -ENOMEM; |
1da177e4 LT |
582 | |
583 | strcpy(cp, symname); | |
584 | ||
726a5e06 | 585 | inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555); |
25767378 IK |
586 | if (!inode) { |
587 | kfree(cp); | |
25767378 IK |
588 | return -ENOMEM; |
589 | } | |
292c5ee8 | 590 | inode->i_private = cp; |
0bf71d4d | 591 | inode->i_size = size; |
1864f7bd | 592 | d_add(dentry, inode); |
1da177e4 | 593 | |
5a37db30 | 594 | dget(dentry); |
1aff3c8b IK |
595 | atomic_inc(&ino->count); |
596 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 597 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 598 | atomic_inc(&p_ino->count); |
1da177e4 | 599 | |
078cd827 | 600 | dir->i_mtime = current_time(dir); |
1da177e4 LT |
601 | |
602 | return 0; | |
603 | } | |
604 | ||
605 | /* | |
606 | * NOTE! | |
607 | * | |
608 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
609 | * that the file no longer exists. However, doing that means that the | |
610 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 611 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
612 | * We simply d_drop it and add it to a expiring list in the super block, |
613 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
614 | * |
615 | * If a process is blocked on the dentry waiting for the expire to finish, | |
616 | * it will invalidate the dentry and try to mount with a new one. | |
617 | * | |
618 | * Also see autofs4_dir_rmdir().. | |
619 | */ | |
620 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
621 | { | |
622 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
623 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 624 | struct autofs_info *p_ino; |
0266725a | 625 | |
1da177e4 | 626 | /* This allows root to remove symlinks */ |
d78e53c8 | 627 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
41735818 | 628 | return -EPERM; |
1da177e4 | 629 | |
1aff3c8b IK |
630 | if (atomic_dec_and_test(&ino->count)) { |
631 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 632 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b IK |
633 | atomic_dec(&p_ino->count); |
634 | } | |
1da177e4 LT |
635 | dput(ino->dentry); |
636 | ||
2b0143b5 DH |
637 | d_inode(dentry)->i_size = 0; |
638 | clear_nlink(d_inode(dentry)); | |
1da177e4 | 639 | |
078cd827 | 640 | dir->i_mtime = current_time(dir); |
1da177e4 | 641 | |
e7854723 IK |
642 | spin_lock(&sbi->lookup_lock); |
643 | __autofs4_add_expiring(dentry); | |
0259cb02 | 644 | d_drop(dentry); |
e7854723 | 645 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
646 | |
647 | return 0; | |
648 | } | |
649 | ||
dd89f90d IK |
650 | /* |
651 | * Version 4 of autofs provides a pseudo direct mount implementation | |
652 | * that relies on directories at the leaves of a directory tree under | |
653 | * an indirect mount to trigger mounts. To allow for this we need to | |
654 | * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves | |
655 | * of the directory tree. There is no need to clear the automount flag | |
656 | * following a mount or restore it after an expire because these mounts | |
25985edc | 657 | * are always covered. However, it is necessary to ensure that these |
dd89f90d IK |
658 | * flags are clear on non-empty directories to avoid unnecessary calls |
659 | * during path walks. | |
660 | */ | |
661 | static void autofs_set_leaf_automount_flags(struct dentry *dentry) | |
662 | { | |
663 | struct dentry *parent; | |
664 | ||
665 | /* root and dentrys in the root are already handled */ | |
666 | if (IS_ROOT(dentry->d_parent)) | |
667 | return; | |
668 | ||
669 | managed_dentry_set_managed(dentry); | |
670 | ||
671 | parent = dentry->d_parent; | |
672 | /* only consider parents below dentrys in the root */ | |
673 | if (IS_ROOT(parent->d_parent)) | |
674 | return; | |
675 | managed_dentry_clear_managed(parent); | |
dd89f90d IK |
676 | } |
677 | ||
678 | static void autofs_clear_leaf_automount_flags(struct dentry *dentry) | |
679 | { | |
680 | struct list_head *d_child; | |
681 | struct dentry *parent; | |
682 | ||
683 | /* flags for dentrys in the root are handled elsewhere */ | |
684 | if (IS_ROOT(dentry->d_parent)) | |
685 | return; | |
686 | ||
687 | managed_dentry_clear_managed(dentry); | |
688 | ||
689 | parent = dentry->d_parent; | |
690 | /* only consider parents below dentrys in the root */ | |
691 | if (IS_ROOT(parent->d_parent)) | |
692 | return; | |
946e51f2 | 693 | d_child = &dentry->d_child; |
dd89f90d IK |
694 | /* Set parent managed if it's becoming empty */ |
695 | if (d_child->next == &parent->d_subdirs && | |
696 | d_child->prev == &parent->d_subdirs) | |
697 | managed_dentry_set_managed(parent); | |
dd89f90d IK |
698 | } |
699 | ||
1da177e4 LT |
700 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
701 | { | |
702 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
703 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 704 | struct autofs_info *p_ino; |
0266725a | 705 | |
8a78d593 | 706 | pr_debug("dentry %p, removing %pd\n", dentry, dentry); |
f50b6f86 | 707 | |
1da177e4 LT |
708 | if (!autofs4_oz_mode(sbi)) |
709 | return -EACCES; | |
710 | ||
2fd6b7f5 | 711 | spin_lock(&sbi->lookup_lock); |
0259cb02 | 712 | if (!simple_empty(dentry)) { |
2fd6b7f5 | 713 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
714 | return -ENOTEMPTY; |
715 | } | |
2fd6b7f5 | 716 | __autofs4_add_expiring(dentry); |
0259cb02 | 717 | d_drop(dentry); |
e7854723 | 718 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 719 | |
dd89f90d IK |
720 | if (sbi->version < 5) |
721 | autofs_clear_leaf_automount_flags(dentry); | |
722 | ||
1aff3c8b IK |
723 | if (atomic_dec_and_test(&ino->count)) { |
724 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
725 | if (p_ino && dentry->d_parent != dentry) | |
726 | atomic_dec(&p_ino->count); | |
727 | } | |
1da177e4 | 728 | dput(ino->dentry); |
2b0143b5 DH |
729 | d_inode(dentry)->i_size = 0; |
730 | clear_nlink(d_inode(dentry)); | |
1da177e4 LT |
731 | |
732 | if (dir->i_nlink) | |
9a53c3a7 | 733 | drop_nlink(dir); |
1da177e4 LT |
734 | |
735 | return 0; | |
736 | } | |
737 | ||
e9a7c2f1 IK |
738 | static int autofs4_dir_mkdir(struct inode *dir, |
739 | struct dentry *dentry, umode_t mode) | |
1da177e4 LT |
740 | { |
741 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
742 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 743 | struct autofs_info *p_ino; |
1da177e4 LT |
744 | struct inode *inode; |
745 | ||
d78e53c8 | 746 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
747 | return -EACCES; |
748 | ||
8a78d593 | 749 | pr_debug("dentry %p, creating %pd\n", dentry, dentry); |
1da177e4 | 750 | |
5a37db30 AV |
751 | BUG_ON(!ino); |
752 | ||
26e6c910 | 753 | autofs4_clean_ino(ino); |
25767378 | 754 | |
4b1ae27a AV |
755 | autofs4_del_active(dentry); |
756 | ||
726a5e06 | 757 | inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555); |
5a37db30 | 758 | if (!inode) |
25767378 | 759 | return -ENOMEM; |
1864f7bd | 760 | d_add(dentry, inode); |
1da177e4 | 761 | |
dd89f90d IK |
762 | if (sbi->version < 5) |
763 | autofs_set_leaf_automount_flags(dentry); | |
764 | ||
5a37db30 | 765 | dget(dentry); |
1aff3c8b IK |
766 | atomic_inc(&ino->count); |
767 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 768 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 769 | atomic_inc(&p_ino->count); |
d8c76e6f | 770 | inc_nlink(dir); |
078cd827 | 771 | dir->i_mtime = current_time(dir); |
1da177e4 LT |
772 | |
773 | return 0; | |
774 | } | |
775 | ||
776 | /* Get/set timeout ioctl() operation */ | |
c9243f5b AB |
777 | #ifdef CONFIG_COMPAT |
778 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, | |
e9a7c2f1 | 779 | compat_ulong_t __user *p) |
c9243f5b | 780 | { |
c9243f5b | 781 | unsigned long ntimeout; |
aa330ddc IK |
782 | int rv; |
783 | ||
784 | rv = get_user(ntimeout, p); | |
785 | if (rv) | |
786 | goto error; | |
c9243f5b | 787 | |
aa330ddc IK |
788 | rv = put_user(sbi->exp_timeout/HZ, p); |
789 | if (rv) | |
790 | goto error; | |
c9243f5b AB |
791 | |
792 | if (ntimeout > UINT_MAX/HZ) | |
793 | sbi->exp_timeout = 0; | |
794 | else | |
795 | sbi->exp_timeout = ntimeout * HZ; | |
796 | ||
797 | return 0; | |
aa330ddc IK |
798 | error: |
799 | return rv; | |
c9243f5b AB |
800 | } |
801 | #endif | |
802 | ||
1da177e4 | 803 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
e9a7c2f1 | 804 | unsigned long __user *p) |
1da177e4 | 805 | { |
1da177e4 | 806 | unsigned long ntimeout; |
aa330ddc IK |
807 | int rv; |
808 | ||
809 | rv = get_user(ntimeout, p); | |
810 | if (rv) | |
811 | goto error; | |
1da177e4 | 812 | |
aa330ddc IK |
813 | rv = put_user(sbi->exp_timeout/HZ, p); |
814 | if (rv) | |
815 | goto error; | |
1da177e4 | 816 | |
d78e53c8 | 817 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
818 | sbi->exp_timeout = 0; |
819 | else | |
820 | sbi->exp_timeout = ntimeout * HZ; | |
821 | ||
822 | return 0; | |
aa330ddc IK |
823 | error: |
824 | return rv; | |
1da177e4 LT |
825 | } |
826 | ||
827 | /* Return protocol version */ | |
e9a7c2f1 IK |
828 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, |
829 | int __user *p) | |
1da177e4 LT |
830 | { |
831 | return put_user(sbi->version, p); | |
832 | } | |
833 | ||
834 | /* Return protocol sub version */ | |
e9a7c2f1 IK |
835 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, |
836 | int __user *p) | |
1da177e4 LT |
837 | { |
838 | return put_user(sbi->sub_version, p); | |
839 | } | |
840 | ||
1da177e4 LT |
841 | /* |
842 | * Tells the daemon whether it can umount the autofs mount. | |
843 | */ | |
844 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
845 | { | |
846 | int status = 0; | |
847 | ||
e3474a8e | 848 | if (may_umount(mnt)) |
1da177e4 LT |
849 | status = 1; |
850 | ||
b6e3795a | 851 | pr_debug("may umount %d\n", status); |
1da177e4 LT |
852 | |
853 | status = put_user(status, p); | |
854 | ||
855 | return status; | |
856 | } | |
857 | ||
858 | /* Identify autofs4_dentries - this is so we can tell if there's | |
e9a7c2f1 IK |
859 | * an extra dentry refcount or not. We only hold a refcount on the |
860 | * dentry if its non-negative (ie, d_inode != NULL) | |
861 | */ | |
1da177e4 LT |
862 | int is_autofs4_dentry(struct dentry *dentry) |
863 | { | |
2b0143b5 | 864 | return dentry && d_really_is_positive(dentry) && |
b650c858 | 865 | dentry->d_op == &autofs4_dentry_operations && |
1da177e4 LT |
866 | dentry->d_fsdata != NULL; |
867 | } | |
868 | ||
869 | /* | |
870 | * ioctl()'s on the root directory is the chief method for the daemon to | |
871 | * generate kernel reactions | |
872 | */ | |
3663df70 FW |
873 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
874 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
875 | { |
876 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
877 | void __user *p = (void __user *)arg; | |
878 | ||
8a78d593 IK |
879 | pr_debug("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n", |
880 | cmd, arg, sbi, task_pgrp_nr(current)); | |
1da177e4 | 881 | |
d78e53c8 SB |
882 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
883 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 | 884 | return -ENOTTY; |
0266725a | 885 | |
d78e53c8 | 886 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 | 887 | return -EPERM; |
0266725a | 888 | |
e9a7c2f1 | 889 | switch (cmd) { |
1da177e4 | 890 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ |
e9a7c2f1 | 891 | return autofs4_wait_release(sbi, (autofs_wqt_t) arg, 0); |
1da177e4 | 892 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ |
e9a7c2f1 | 893 | return autofs4_wait_release(sbi, (autofs_wqt_t) arg, -ENOENT); |
1da177e4 LT |
894 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ |
895 | autofs4_catatonic_mode(sbi); | |
896 | return 0; | |
897 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
898 | return autofs4_get_protover(sbi, p); | |
899 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
900 | return autofs4_get_protosubver(sbi, p); | |
901 | case AUTOFS_IOC_SETTIMEOUT: | |
902 | return autofs4_get_set_timeout(sbi, p); | |
c9243f5b AB |
903 | #ifdef CONFIG_COMPAT |
904 | case AUTOFS_IOC_SETTIMEOUT32: | |
905 | return autofs4_compat_get_set_timeout(sbi, p); | |
906 | #endif | |
1da177e4 | 907 | |
1da177e4 | 908 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 909 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
910 | |
911 | /* return a single thing to expire */ | |
912 | case AUTOFS_IOC_EXPIRE: | |
e9a7c2f1 IK |
913 | return autofs4_expire_run(inode->i_sb, |
914 | filp->f_path.mnt, sbi, p); | |
1da177e4 LT |
915 | /* same as above, but can send multiple expires through pipe */ |
916 | case AUTOFS_IOC_EXPIRE_MULTI: | |
e9a7c2f1 IK |
917 | return autofs4_expire_multi(inode->i_sb, |
918 | filp->f_path.mnt, sbi, p); | |
1da177e4 LT |
919 | |
920 | default: | |
e3cd8067 | 921 | return -EINVAL; |
1da177e4 LT |
922 | } |
923 | } | |
3663df70 FW |
924 | |
925 | static long autofs4_root_ioctl(struct file *filp, | |
926 | unsigned int cmd, unsigned long arg) | |
927 | { | |
496ad9aa | 928 | struct inode *inode = file_inode(filp); |
e9a7c2f1 | 929 | |
de47de74 | 930 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
3663df70 | 931 | } |
c9243f5b AB |
932 | |
933 | #ifdef CONFIG_COMPAT | |
934 | static long autofs4_root_compat_ioctl(struct file *filp, | |
e9a7c2f1 | 935 | unsigned int cmd, unsigned long arg) |
c9243f5b | 936 | { |
496ad9aa | 937 | struct inode *inode = file_inode(filp); |
c9243f5b AB |
938 | int ret; |
939 | ||
c9243f5b AB |
940 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
941 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); | |
942 | else | |
943 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, | |
e9a7c2f1 | 944 | (unsigned long) compat_ptr(arg)); |
c9243f5b AB |
945 | |
946 | return ret; | |
947 | } | |
948 | #endif |