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Commit | Line | Data |
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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); |
10584211 | 284 | } |
43694d4b | 285 | ino->last_used = jiffies; |
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; | |
43694d4b | 324 | struct autofs_info *ino; |
e9a7c2f1 IK |
325 | struct dentry *new; |
326 | ||
327 | new = d_lookup(parent, &dentry->d_name); | |
10584211 IK |
328 | if (!new) |
329 | return NULL; | |
43694d4b IK |
330 | ino = autofs4_dentry_ino(new); |
331 | ino->last_used = jiffies; | |
332 | dput(path->dentry); | |
333 | path->dentry = new; | |
10584211 IK |
334 | } |
335 | return path->dentry; | |
336 | } | |
337 | ||
71e469db | 338 | static struct vfsmount *autofs4_d_automount(struct path *path) |
10584211 IK |
339 | { |
340 | struct dentry *dentry = path->dentry; | |
341 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
342 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
343 | int status; | |
344 | ||
8a78d593 | 345 | pr_debug("dentry=%p %pd\n", dentry, dentry); |
10584211 IK |
346 | |
347 | /* The daemon never triggers a mount. */ | |
348 | if (autofs4_oz_mode(sbi)) | |
349 | return NULL; | |
350 | ||
351 | /* | |
352 | * If an expire request is pending everyone must wait. | |
353 | * If the expire fails we're still mounted so continue | |
354 | * the follow and return. A return of -EAGAIN (which only | |
355 | * happens with indirect mounts) means the expire completed | |
356 | * and the directory was removed, so just go ahead and try | |
357 | * the mount. | |
358 | */ | |
74f504cf | 359 | status = do_expire_wait(path, 0); |
10584211 IK |
360 | if (status && status != -EAGAIN) |
361 | return NULL; | |
362 | ||
363 | /* Callback to the daemon to perform the mount or wait */ | |
364 | spin_lock(&sbi->fs_lock); | |
365 | if (ino->flags & AUTOFS_INF_PENDING) { | |
366 | spin_unlock(&sbi->fs_lock); | |
dd36a882 | 367 | status = autofs4_mount_wait(path, 0); |
10584211 IK |
368 | if (status) |
369 | return ERR_PTR(status); | |
10584211 IK |
370 | goto done; |
371 | } | |
372 | ||
373 | /* | |
374 | * If the dentry is a symlink it's equivalent to a directory | |
cfaf86ab IK |
375 | * having path_is_mountpoint() true, so there's no need to call |
376 | * back to the daemon. | |
10584211 | 377 | */ |
2b0143b5 | 378 | if (d_really_is_positive(dentry) && d_is_symlink(dentry)) { |
f55fb0c2 | 379 | spin_unlock(&sbi->fs_lock); |
10584211 | 380 | goto done; |
f55fb0c2 IK |
381 | } |
382 | ||
cfaf86ab | 383 | if (!path_is_mountpoint(path)) { |
b5b80177 IK |
384 | /* |
385 | * It's possible that user space hasn't removed directories | |
386 | * after umounting a rootless multi-mount, although it | |
60359741 IK |
387 | * should. For v5 path_has_submounts() is sufficient to |
388 | * handle this because the leaves of the directory tree under | |
389 | * the mount never trigger mounts themselves (they have an | |
390 | * autofs trigger mount mounted on them). But v4 pseudo direct | |
391 | * mounts do need the leaves to trigger mounts. In this case | |
392 | * we have no choice but to use the list_empty() check and | |
b5b80177 IK |
393 | * require user space behave. |
394 | */ | |
395 | if (sbi->version > 4) { | |
60359741 | 396 | if (path_has_submounts(path)) { |
f55fb0c2 | 397 | spin_unlock(&sbi->fs_lock); |
b5b80177 | 398 | goto done; |
f55fb0c2 | 399 | } |
b5b80177 | 400 | } else { |
9d8072e7 PH |
401 | if (!simple_empty(dentry)) { |
402 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 403 | goto done; |
9d8072e7 | 404 | } |
b5b80177 | 405 | } |
10584211 | 406 | ino->flags |= AUTOFS_INF_PENDING; |
10584211 | 407 | spin_unlock(&sbi->fs_lock); |
dd36a882 | 408 | status = autofs4_mount_wait(path, 0); |
10584211 IK |
409 | spin_lock(&sbi->fs_lock); |
410 | ino->flags &= ~AUTOFS_INF_PENDING; | |
49999ab2 IK |
411 | if (status) { |
412 | spin_unlock(&sbi->fs_lock); | |
413 | return ERR_PTR(status); | |
414 | } | |
10584211 | 415 | } |
10584211 | 416 | spin_unlock(&sbi->fs_lock); |
f55fb0c2 | 417 | done: |
10584211 IK |
418 | /* Mount succeeded, check if we ended up with a new dentry */ |
419 | dentry = autofs4_mountpoint_changed(path); | |
420 | if (!dentry) | |
421 | return ERR_PTR(-ENOENT); | |
422 | ||
423 | return NULL; | |
424 | } | |
425 | ||
fb5f51c7 | 426 | static int autofs4_d_manage(const struct path *path, bool rcu_walk) |
b5b80177 | 427 | { |
fb5f51c7 | 428 | struct dentry *dentry = path->dentry; |
b5b80177 | 429 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f55fb0c2 IK |
430 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
431 | int status; | |
b5b80177 | 432 | |
8a78d593 | 433 | pr_debug("dentry=%p %pd\n", dentry, dentry); |
b5b80177 IK |
434 | |
435 | /* The daemon never waits. */ | |
1aed3e42 | 436 | if (autofs4_oz_mode(sbi)) { |
cfaf86ab | 437 | if (!path_is_mountpoint(path)) |
b5b80177 IK |
438 | return -EISDIR; |
439 | return 0; | |
440 | } | |
441 | ||
442 | /* Wait for pending expires */ | |
74f504cf | 443 | if (do_expire_wait(path, rcu_walk) == -ECHILD) |
23bfc2a2 | 444 | return -ECHILD; |
b5b80177 IK |
445 | |
446 | /* | |
447 | * This dentry may be under construction so wait on mount | |
448 | * completion. | |
449 | */ | |
dd36a882 | 450 | status = autofs4_mount_wait(path, rcu_walk); |
f55fb0c2 IK |
451 | if (status) |
452 | return status; | |
453 | ||
ef16cc59 N |
454 | if (rcu_walk) { |
455 | /* We don't need fs_lock in rcu_walk mode, | |
456 | * just testing 'AUTOFS_INFO_NO_RCU' is enough. | |
457 | * simple_empty() takes a spinlock, so leave it | |
458 | * to last. | |
459 | * We only return -EISDIR when certain this isn't | |
460 | * a mount-trap. | |
23bfc2a2 | 461 | */ |
ef16cc59 | 462 | struct inode *inode; |
e9a7c2f1 | 463 | |
ea01a184 | 464 | if (ino->flags & AUTOFS_INF_WANT_EXPIRE) |
ef16cc59 | 465 | return 0; |
cfaf86ab | 466 | if (path_is_mountpoint(path)) |
ef16cc59 | 467 | return 0; |
2b0143b5 | 468 | inode = d_inode_rcu(dentry); |
ef16cc59 N |
469 | if (inode && S_ISLNK(inode->i_mode)) |
470 | return -EISDIR; | |
471 | if (list_empty(&dentry->d_subdirs)) | |
472 | return 0; | |
473 | if (!simple_empty(dentry)) | |
474 | return -EISDIR; | |
23bfc2a2 | 475 | return 0; |
ef16cc59 | 476 | } |
23bfc2a2 | 477 | |
f55fb0c2 IK |
478 | spin_lock(&sbi->fs_lock); |
479 | /* | |
480 | * If the dentry has been selected for expire while we slept | |
481 | * on the lock then it might go away. We'll deal with that in | |
482 | * ->d_automount() and wait on a new mount if the expire | |
483 | * succeeds or return here if it doesn't (since there's no | |
484 | * mount to follow with a rootless multi-mount). | |
485 | */ | |
486 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { | |
487 | /* | |
488 | * Any needed mounting has been completed and the path | |
489 | * updated so check if this is a rootless multi-mount so | |
490 | * we can avoid needless calls ->d_automount() and avoid | |
491 | * an incorrect ELOOP error return. | |
492 | */ | |
cfaf86ab | 493 | if ((!path_is_mountpoint(path) && !simple_empty(dentry)) || |
2b0143b5 | 494 | (d_really_is_positive(dentry) && d_is_symlink(dentry))) |
f55fb0c2 IK |
495 | status = -EISDIR; |
496 | } | |
497 | spin_unlock(&sbi->fs_lock); | |
498 | ||
499 | return status; | |
b5b80177 IK |
500 | } |
501 | ||
1da177e4 | 502 | /* Lookups in the root directory */ |
e9a7c2f1 IK |
503 | static struct dentry *autofs4_lookup(struct inode *dir, |
504 | struct dentry *dentry, unsigned int flags) | |
1da177e4 LT |
505 | { |
506 | struct autofs_sb_info *sbi; | |
25767378 | 507 | struct autofs_info *ino; |
10584211 | 508 | struct dentry *active; |
1da177e4 | 509 | |
8a78d593 | 510 | pr_debug("name = %pd\n", dentry); |
1da177e4 | 511 | |
718c604a | 512 | /* File name too long to exist */ |
1da177e4 | 513 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 514 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
515 | |
516 | sbi = autofs4_sbi(dir->i_sb); | |
718c604a | 517 | |
8a78d593 IK |
518 | pr_debug("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n", |
519 | current->pid, task_pgrp_nr(current), sbi->catatonic, | |
520 | autofs4_oz_mode(sbi)); | |
1da177e4 | 521 | |
6510c9d8 | 522 | active = autofs4_lookup_active(dentry); |
e9a7c2f1 | 523 | if (active) |
10584211 | 524 | return active; |
e9a7c2f1 | 525 | else { |
4b1ae27a | 526 | /* |
10584211 IK |
527 | * A dentry that is not within the root can never trigger a |
528 | * mount operation, unless the directory already exists, so we | |
529 | * can return fail immediately. The daemon however does need | |
530 | * to create directories within the file system. | |
4b1ae27a | 531 | */ |
10584211 IK |
532 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
533 | return ERR_PTR(-ENOENT); | |
534 | ||
535 | /* Mark entries in the root as mount triggers */ | |
e9a7c2f1 IK |
536 | if (IS_ROOT(dentry->d_parent) && |
537 | autofs_type_indirect(sbi->type)) | |
b5b80177 | 538 | __managed_dentry_set_managed(dentry); |
10584211 | 539 | |
26e6c910 | 540 | ino = autofs4_new_ino(sbi); |
4b1ae27a AV |
541 | if (!ino) |
542 | return ERR_PTR(-ENOMEM); | |
543 | ||
544 | dentry->d_fsdata = ino; | |
545 | ino->dentry = dentry; | |
5f6f4f28 | 546 | |
4b1ae27a | 547 | autofs4_add_active(dentry); |
4b1ae27a | 548 | } |
1da177e4 LT |
549 | return NULL; |
550 | } | |
551 | ||
552 | static int autofs4_dir_symlink(struct inode *dir, | |
553 | struct dentry *dentry, | |
554 | const char *symname) | |
555 | { | |
556 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
557 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 558 | struct autofs_info *p_ino; |
1da177e4 | 559 | struct inode *inode; |
0bf71d4d | 560 | size_t size = strlen(symname); |
1da177e4 LT |
561 | char *cp; |
562 | ||
8a78d593 | 563 | pr_debug("%s <- %pd\n", symname, dentry); |
1da177e4 LT |
564 | |
565 | if (!autofs4_oz_mode(sbi)) | |
566 | return -EACCES; | |
567 | ||
5a37db30 AV |
568 | BUG_ON(!ino); |
569 | ||
26e6c910 | 570 | autofs4_clean_ino(ino); |
1da177e4 | 571 | |
4b1ae27a AV |
572 | autofs4_del_active(dentry); |
573 | ||
0bf71d4d | 574 | cp = kmalloc(size + 1, GFP_KERNEL); |
5a37db30 | 575 | if (!cp) |
25767378 | 576 | return -ENOMEM; |
1da177e4 LT |
577 | |
578 | strcpy(cp, symname); | |
579 | ||
726a5e06 | 580 | inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555); |
25767378 IK |
581 | if (!inode) { |
582 | kfree(cp); | |
25767378 IK |
583 | return -ENOMEM; |
584 | } | |
292c5ee8 | 585 | inode->i_private = cp; |
0bf71d4d | 586 | inode->i_size = size; |
1864f7bd | 587 | d_add(dentry, inode); |
1da177e4 | 588 | |
5a37db30 | 589 | dget(dentry); |
1aff3c8b IK |
590 | atomic_inc(&ino->count); |
591 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 592 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 593 | atomic_inc(&p_ino->count); |
1da177e4 | 594 | |
078cd827 | 595 | dir->i_mtime = current_time(dir); |
1da177e4 LT |
596 | |
597 | return 0; | |
598 | } | |
599 | ||
600 | /* | |
601 | * NOTE! | |
602 | * | |
603 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
604 | * that the file no longer exists. However, doing that means that the | |
605 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 606 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
607 | * We simply d_drop it and add it to a expiring list in the super block, |
608 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
609 | * |
610 | * If a process is blocked on the dentry waiting for the expire to finish, | |
611 | * it will invalidate the dentry and try to mount with a new one. | |
612 | * | |
613 | * Also see autofs4_dir_rmdir().. | |
614 | */ | |
615 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
616 | { | |
617 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
618 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 619 | struct autofs_info *p_ino; |
0266725a | 620 | |
1da177e4 | 621 | /* This allows root to remove symlinks */ |
d78e53c8 | 622 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
41735818 | 623 | return -EPERM; |
1da177e4 | 624 | |
1aff3c8b IK |
625 | if (atomic_dec_and_test(&ino->count)) { |
626 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 627 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b IK |
628 | atomic_dec(&p_ino->count); |
629 | } | |
1da177e4 LT |
630 | dput(ino->dentry); |
631 | ||
2b0143b5 DH |
632 | d_inode(dentry)->i_size = 0; |
633 | clear_nlink(d_inode(dentry)); | |
1da177e4 | 634 | |
078cd827 | 635 | dir->i_mtime = current_time(dir); |
1da177e4 | 636 | |
e7854723 IK |
637 | spin_lock(&sbi->lookup_lock); |
638 | __autofs4_add_expiring(dentry); | |
0259cb02 | 639 | d_drop(dentry); |
e7854723 | 640 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
641 | |
642 | return 0; | |
643 | } | |
644 | ||
dd89f90d IK |
645 | /* |
646 | * Version 4 of autofs provides a pseudo direct mount implementation | |
647 | * that relies on directories at the leaves of a directory tree under | |
648 | * an indirect mount to trigger mounts. To allow for this we need to | |
649 | * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves | |
650 | * of the directory tree. There is no need to clear the automount flag | |
651 | * following a mount or restore it after an expire because these mounts | |
25985edc | 652 | * are always covered. However, it is necessary to ensure that these |
dd89f90d IK |
653 | * flags are clear on non-empty directories to avoid unnecessary calls |
654 | * during path walks. | |
655 | */ | |
656 | static void autofs_set_leaf_automount_flags(struct dentry *dentry) | |
657 | { | |
658 | struct dentry *parent; | |
659 | ||
660 | /* root and dentrys in the root are already handled */ | |
661 | if (IS_ROOT(dentry->d_parent)) | |
662 | return; | |
663 | ||
664 | managed_dentry_set_managed(dentry); | |
665 | ||
666 | parent = dentry->d_parent; | |
667 | /* only consider parents below dentrys in the root */ | |
668 | if (IS_ROOT(parent->d_parent)) | |
669 | return; | |
670 | managed_dentry_clear_managed(parent); | |
dd89f90d IK |
671 | } |
672 | ||
673 | static void autofs_clear_leaf_automount_flags(struct dentry *dentry) | |
674 | { | |
675 | struct list_head *d_child; | |
676 | struct dentry *parent; | |
677 | ||
678 | /* flags for dentrys in the root are handled elsewhere */ | |
679 | if (IS_ROOT(dentry->d_parent)) | |
680 | return; | |
681 | ||
682 | managed_dentry_clear_managed(dentry); | |
683 | ||
684 | parent = dentry->d_parent; | |
685 | /* only consider parents below dentrys in the root */ | |
686 | if (IS_ROOT(parent->d_parent)) | |
687 | return; | |
946e51f2 | 688 | d_child = &dentry->d_child; |
dd89f90d IK |
689 | /* Set parent managed if it's becoming empty */ |
690 | if (d_child->next == &parent->d_subdirs && | |
691 | d_child->prev == &parent->d_subdirs) | |
692 | managed_dentry_set_managed(parent); | |
dd89f90d IK |
693 | } |
694 | ||
1da177e4 LT |
695 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
696 | { | |
697 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
698 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 699 | struct autofs_info *p_ino; |
0266725a | 700 | |
8a78d593 | 701 | pr_debug("dentry %p, removing %pd\n", dentry, dentry); |
f50b6f86 | 702 | |
1da177e4 LT |
703 | if (!autofs4_oz_mode(sbi)) |
704 | return -EACCES; | |
705 | ||
2fd6b7f5 | 706 | spin_lock(&sbi->lookup_lock); |
0259cb02 | 707 | if (!simple_empty(dentry)) { |
2fd6b7f5 | 708 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
709 | return -ENOTEMPTY; |
710 | } | |
2fd6b7f5 | 711 | __autofs4_add_expiring(dentry); |
0259cb02 | 712 | d_drop(dentry); |
e7854723 | 713 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 714 | |
dd89f90d IK |
715 | if (sbi->version < 5) |
716 | autofs_clear_leaf_automount_flags(dentry); | |
717 | ||
1aff3c8b IK |
718 | if (atomic_dec_and_test(&ino->count)) { |
719 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
720 | if (p_ino && dentry->d_parent != dentry) | |
721 | atomic_dec(&p_ino->count); | |
722 | } | |
1da177e4 | 723 | dput(ino->dentry); |
2b0143b5 DH |
724 | d_inode(dentry)->i_size = 0; |
725 | clear_nlink(d_inode(dentry)); | |
1da177e4 LT |
726 | |
727 | if (dir->i_nlink) | |
9a53c3a7 | 728 | drop_nlink(dir); |
1da177e4 LT |
729 | |
730 | return 0; | |
731 | } | |
732 | ||
e9a7c2f1 IK |
733 | static int autofs4_dir_mkdir(struct inode *dir, |
734 | struct dentry *dentry, umode_t mode) | |
1da177e4 LT |
735 | { |
736 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
737 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 738 | struct autofs_info *p_ino; |
1da177e4 LT |
739 | struct inode *inode; |
740 | ||
d78e53c8 | 741 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
742 | return -EACCES; |
743 | ||
8a78d593 | 744 | pr_debug("dentry %p, creating %pd\n", dentry, dentry); |
1da177e4 | 745 | |
5a37db30 AV |
746 | BUG_ON(!ino); |
747 | ||
26e6c910 | 748 | autofs4_clean_ino(ino); |
25767378 | 749 | |
4b1ae27a AV |
750 | autofs4_del_active(dentry); |
751 | ||
726a5e06 | 752 | inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555); |
5a37db30 | 753 | if (!inode) |
25767378 | 754 | return -ENOMEM; |
1864f7bd | 755 | d_add(dentry, inode); |
1da177e4 | 756 | |
dd89f90d IK |
757 | if (sbi->version < 5) |
758 | autofs_set_leaf_automount_flags(dentry); | |
759 | ||
5a37db30 | 760 | dget(dentry); |
1aff3c8b IK |
761 | atomic_inc(&ino->count); |
762 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 763 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 764 | atomic_inc(&p_ino->count); |
d8c76e6f | 765 | inc_nlink(dir); |
078cd827 | 766 | dir->i_mtime = current_time(dir); |
1da177e4 LT |
767 | |
768 | return 0; | |
769 | } | |
770 | ||
771 | /* Get/set timeout ioctl() operation */ | |
c9243f5b AB |
772 | #ifdef CONFIG_COMPAT |
773 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, | |
e9a7c2f1 | 774 | compat_ulong_t __user *p) |
c9243f5b | 775 | { |
c9243f5b | 776 | unsigned long ntimeout; |
aa330ddc IK |
777 | int rv; |
778 | ||
779 | rv = get_user(ntimeout, p); | |
780 | if (rv) | |
781 | goto error; | |
c9243f5b | 782 | |
aa330ddc IK |
783 | rv = put_user(sbi->exp_timeout/HZ, p); |
784 | if (rv) | |
785 | goto error; | |
c9243f5b AB |
786 | |
787 | if (ntimeout > UINT_MAX/HZ) | |
788 | sbi->exp_timeout = 0; | |
789 | else | |
790 | sbi->exp_timeout = ntimeout * HZ; | |
791 | ||
792 | return 0; | |
aa330ddc IK |
793 | error: |
794 | return rv; | |
c9243f5b AB |
795 | } |
796 | #endif | |
797 | ||
1da177e4 | 798 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
e9a7c2f1 | 799 | unsigned long __user *p) |
1da177e4 | 800 | { |
1da177e4 | 801 | unsigned long ntimeout; |
aa330ddc IK |
802 | int rv; |
803 | ||
804 | rv = get_user(ntimeout, p); | |
805 | if (rv) | |
806 | goto error; | |
1da177e4 | 807 | |
aa330ddc IK |
808 | rv = put_user(sbi->exp_timeout/HZ, p); |
809 | if (rv) | |
810 | goto error; | |
1da177e4 | 811 | |
d78e53c8 | 812 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
813 | sbi->exp_timeout = 0; |
814 | else | |
815 | sbi->exp_timeout = ntimeout * HZ; | |
816 | ||
817 | return 0; | |
aa330ddc IK |
818 | error: |
819 | return rv; | |
1da177e4 LT |
820 | } |
821 | ||
822 | /* Return protocol version */ | |
e9a7c2f1 IK |
823 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, |
824 | int __user *p) | |
1da177e4 LT |
825 | { |
826 | return put_user(sbi->version, p); | |
827 | } | |
828 | ||
829 | /* Return protocol sub version */ | |
e9a7c2f1 IK |
830 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, |
831 | int __user *p) | |
1da177e4 LT |
832 | { |
833 | return put_user(sbi->sub_version, p); | |
834 | } | |
835 | ||
1da177e4 LT |
836 | /* |
837 | * Tells the daemon whether it can umount the autofs mount. | |
838 | */ | |
839 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
840 | { | |
841 | int status = 0; | |
842 | ||
e3474a8e | 843 | if (may_umount(mnt)) |
1da177e4 LT |
844 | status = 1; |
845 | ||
b6e3795a | 846 | pr_debug("may umount %d\n", status); |
1da177e4 LT |
847 | |
848 | status = put_user(status, p); | |
849 | ||
850 | return status; | |
851 | } | |
852 | ||
853 | /* Identify autofs4_dentries - this is so we can tell if there's | |
e9a7c2f1 IK |
854 | * an extra dentry refcount or not. We only hold a refcount on the |
855 | * dentry if its non-negative (ie, d_inode != NULL) | |
856 | */ | |
1da177e4 LT |
857 | int is_autofs4_dentry(struct dentry *dentry) |
858 | { | |
2b0143b5 | 859 | return dentry && d_really_is_positive(dentry) && |
b650c858 | 860 | dentry->d_op == &autofs4_dentry_operations && |
1da177e4 LT |
861 | dentry->d_fsdata != NULL; |
862 | } | |
863 | ||
864 | /* | |
865 | * ioctl()'s on the root directory is the chief method for the daemon to | |
866 | * generate kernel reactions | |
867 | */ | |
3663df70 FW |
868 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
869 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
870 | { |
871 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
872 | void __user *p = (void __user *)arg; | |
873 | ||
8a78d593 IK |
874 | pr_debug("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n", |
875 | cmd, arg, sbi, task_pgrp_nr(current)); | |
1da177e4 | 876 | |
d78e53c8 SB |
877 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
878 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 | 879 | return -ENOTTY; |
0266725a | 880 | |
d78e53c8 | 881 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 | 882 | return -EPERM; |
0266725a | 883 | |
e9a7c2f1 | 884 | switch (cmd) { |
1da177e4 | 885 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ |
e9a7c2f1 | 886 | return autofs4_wait_release(sbi, (autofs_wqt_t) arg, 0); |
1da177e4 | 887 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ |
e9a7c2f1 | 888 | return autofs4_wait_release(sbi, (autofs_wqt_t) arg, -ENOENT); |
1da177e4 LT |
889 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ |
890 | autofs4_catatonic_mode(sbi); | |
891 | return 0; | |
892 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
893 | return autofs4_get_protover(sbi, p); | |
894 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
895 | return autofs4_get_protosubver(sbi, p); | |
896 | case AUTOFS_IOC_SETTIMEOUT: | |
897 | return autofs4_get_set_timeout(sbi, p); | |
c9243f5b AB |
898 | #ifdef CONFIG_COMPAT |
899 | case AUTOFS_IOC_SETTIMEOUT32: | |
900 | return autofs4_compat_get_set_timeout(sbi, p); | |
901 | #endif | |
1da177e4 | 902 | |
1da177e4 | 903 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 904 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
905 | |
906 | /* return a single thing to expire */ | |
907 | case AUTOFS_IOC_EXPIRE: | |
e9a7c2f1 IK |
908 | return autofs4_expire_run(inode->i_sb, |
909 | filp->f_path.mnt, sbi, p); | |
1da177e4 LT |
910 | /* same as above, but can send multiple expires through pipe */ |
911 | case AUTOFS_IOC_EXPIRE_MULTI: | |
e9a7c2f1 IK |
912 | return autofs4_expire_multi(inode->i_sb, |
913 | filp->f_path.mnt, sbi, p); | |
1da177e4 LT |
914 | |
915 | default: | |
e3cd8067 | 916 | return -EINVAL; |
1da177e4 LT |
917 | } |
918 | } | |
3663df70 FW |
919 | |
920 | static long autofs4_root_ioctl(struct file *filp, | |
921 | unsigned int cmd, unsigned long arg) | |
922 | { | |
496ad9aa | 923 | struct inode *inode = file_inode(filp); |
e9a7c2f1 | 924 | |
de47de74 | 925 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
3663df70 | 926 | } |
c9243f5b AB |
927 | |
928 | #ifdef CONFIG_COMPAT | |
929 | static long autofs4_root_compat_ioctl(struct file *filp, | |
e9a7c2f1 | 930 | unsigned int cmd, unsigned long arg) |
c9243f5b | 931 | { |
496ad9aa | 932 | struct inode *inode = file_inode(filp); |
c9243f5b AB |
933 | int ret; |
934 | ||
c9243f5b AB |
935 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
936 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); | |
937 | else | |
938 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, | |
e9a7c2f1 | 939 | (unsigned long) compat_ptr(arg)); |
c9243f5b AB |
940 | |
941 | return ret; | |
942 | } | |
943 | #endif |