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 *); |
1aed3e42 | 35 | static int autofs4_d_manage(struct dentry *, 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, | |
5f99f4e7 | 42 | .iterate = 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, |
5f99f4e7 | 54 | .iterate = 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); |
0259cb02 | 126 | if (!d_mountpoint(dentry) && 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; | |
162 | 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; |
25767378 IK |
175 | struct qstr *qstr; |
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; | |
217 | 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; |
f50b6f86 IK |
230 | struct qstr *qstr; |
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 | ||
23bfc2a2 | 272 | static int autofs4_mount_wait(struct dentry *dentry, bool rcu_walk) |
10584211 IK |
273 | { |
274 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
275 | struct autofs_info *ino = autofs4_dentry_ino(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; | |
8a78d593 | 281 | pr_debug("waiting for mount name=%pd\n", dentry); |
10584211 | 282 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); |
8a78d593 | 283 | pr_debug("mount wait done status=%d\n", status); |
10584211 | 284 | } |
3c319985 IK |
285 | ino->last_used = jiffies; |
286 | return status; | |
10584211 IK |
287 | } |
288 | ||
23bfc2a2 | 289 | static int do_expire_wait(struct dentry *dentry, bool rcu_walk) |
10584211 IK |
290 | { |
291 | struct dentry *expiring; | |
292 | ||
23bfc2a2 N |
293 | expiring = autofs4_lookup_expiring(dentry, rcu_walk); |
294 | if (IS_ERR(expiring)) | |
295 | return PTR_ERR(expiring); | |
10584211 | 296 | if (!expiring) |
23bfc2a2 | 297 | return autofs4_expire_wait(dentry, rcu_walk); |
10584211 IK |
298 | else { |
299 | /* | |
300 | * If we are racing with expire the request might not | |
301 | * be quite complete, but the directory has been removed | |
302 | * so it must have been successful, just wait for it. | |
303 | */ | |
23bfc2a2 | 304 | autofs4_expire_wait(expiring, 0); |
10584211 IK |
305 | autofs4_del_expiring(expiring); |
306 | dput(expiring); | |
307 | } | |
308 | return 0; | |
309 | } | |
310 | ||
311 | static struct dentry *autofs4_mountpoint_changed(struct path *path) | |
312 | { | |
313 | struct dentry *dentry = path->dentry; | |
314 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
315 | ||
316 | /* | |
317 | * If this is an indirect mount the dentry could have gone away | |
318 | * as a result of an expire and a new one created. | |
319 | */ | |
320 | if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { | |
321 | struct dentry *parent = dentry->d_parent; | |
3c319985 | 322 | struct autofs_info *ino; |
e9a7c2f1 IK |
323 | struct dentry *new; |
324 | ||
325 | new = d_lookup(parent, &dentry->d_name); | |
10584211 IK |
326 | if (!new) |
327 | return NULL; | |
3c319985 IK |
328 | ino = autofs4_dentry_ino(new); |
329 | ino->last_used = jiffies; | |
10584211 IK |
330 | dput(path->dentry); |
331 | path->dentry = new; | |
332 | } | |
333 | return path->dentry; | |
334 | } | |
335 | ||
71e469db | 336 | static struct vfsmount *autofs4_d_automount(struct path *path) |
10584211 IK |
337 | { |
338 | struct dentry *dentry = path->dentry; | |
339 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
340 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
341 | int status; | |
342 | ||
8a78d593 | 343 | pr_debug("dentry=%p %pd\n", dentry, dentry); |
10584211 IK |
344 | |
345 | /* The daemon never triggers a mount. */ | |
346 | if (autofs4_oz_mode(sbi)) | |
347 | return NULL; | |
348 | ||
349 | /* | |
350 | * If an expire request is pending everyone must wait. | |
351 | * If the expire fails we're still mounted so continue | |
352 | * the follow and return. A return of -EAGAIN (which only | |
353 | * happens with indirect mounts) means the expire completed | |
354 | * and the directory was removed, so just go ahead and try | |
355 | * the mount. | |
356 | */ | |
23bfc2a2 | 357 | status = do_expire_wait(dentry, 0); |
10584211 IK |
358 | if (status && status != -EAGAIN) |
359 | return NULL; | |
360 | ||
361 | /* Callback to the daemon to perform the mount or wait */ | |
362 | spin_lock(&sbi->fs_lock); | |
363 | if (ino->flags & AUTOFS_INF_PENDING) { | |
364 | spin_unlock(&sbi->fs_lock); | |
23bfc2a2 | 365 | status = autofs4_mount_wait(dentry, 0); |
10584211 IK |
366 | if (status) |
367 | return ERR_PTR(status); | |
10584211 IK |
368 | goto done; |
369 | } | |
370 | ||
371 | /* | |
372 | * If the dentry is a symlink it's equivalent to a directory | |
b5b80177 | 373 | * having d_mountpoint() true, so there's no need to call back |
10584211 IK |
374 | * to the daemon. |
375 | */ | |
2b0143b5 | 376 | if (d_really_is_positive(dentry) && d_is_symlink(dentry)) { |
f55fb0c2 | 377 | spin_unlock(&sbi->fs_lock); |
10584211 | 378 | goto done; |
f55fb0c2 IK |
379 | } |
380 | ||
b5b80177 IK |
381 | if (!d_mountpoint(dentry)) { |
382 | /* | |
383 | * It's possible that user space hasn't removed directories | |
384 | * after umounting a rootless multi-mount, although it | |
385 | * should. For v5 have_submounts() is sufficient to handle | |
386 | * this because the leaves of the directory tree under the | |
387 | * mount never trigger mounts themselves (they have an autofs | |
388 | * trigger mount mounted on them). But v4 pseudo direct mounts | |
3b97dd05 | 389 | * do need the leaves to trigger mounts. In this case we |
b5b80177 IK |
390 | * have no choice but to use the list_empty() check and |
391 | * require user space behave. | |
392 | */ | |
393 | if (sbi->version > 4) { | |
f55fb0c2 IK |
394 | if (have_submounts(dentry)) { |
395 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 396 | goto done; |
f55fb0c2 | 397 | } |
b5b80177 | 398 | } else { |
9d8072e7 PH |
399 | if (!simple_empty(dentry)) { |
400 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 401 | goto done; |
9d8072e7 | 402 | } |
b5b80177 | 403 | } |
10584211 | 404 | ino->flags |= AUTOFS_INF_PENDING; |
10584211 | 405 | spin_unlock(&sbi->fs_lock); |
23bfc2a2 | 406 | status = autofs4_mount_wait(dentry, 0); |
10584211 IK |
407 | spin_lock(&sbi->fs_lock); |
408 | ino->flags &= ~AUTOFS_INF_PENDING; | |
49999ab2 IK |
409 | if (status) { |
410 | spin_unlock(&sbi->fs_lock); | |
411 | return ERR_PTR(status); | |
412 | } | |
10584211 | 413 | } |
10584211 | 414 | spin_unlock(&sbi->fs_lock); |
f55fb0c2 | 415 | done: |
10584211 IK |
416 | /* Mount succeeded, check if we ended up with a new dentry */ |
417 | dentry = autofs4_mountpoint_changed(path); | |
418 | if (!dentry) | |
419 | return ERR_PTR(-ENOENT); | |
420 | ||
421 | return NULL; | |
422 | } | |
423 | ||
95482986 | 424 | static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk) |
b5b80177 IK |
425 | { |
426 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f55fb0c2 IK |
427 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
428 | int status; | |
b5b80177 | 429 | |
8a78d593 | 430 | pr_debug("dentry=%p %pd\n", dentry, dentry); |
b5b80177 IK |
431 | |
432 | /* The daemon never waits. */ | |
1aed3e42 | 433 | if (autofs4_oz_mode(sbi)) { |
b5b80177 IK |
434 | if (!d_mountpoint(dentry)) |
435 | return -EISDIR; | |
436 | return 0; | |
437 | } | |
438 | ||
439 | /* Wait for pending expires */ | |
23bfc2a2 N |
440 | if (do_expire_wait(dentry, rcu_walk) == -ECHILD) |
441 | return -ECHILD; | |
b5b80177 IK |
442 | |
443 | /* | |
444 | * This dentry may be under construction so wait on mount | |
445 | * completion. | |
446 | */ | |
23bfc2a2 | 447 | status = autofs4_mount_wait(dentry, rcu_walk); |
f55fb0c2 IK |
448 | if (status) |
449 | return status; | |
450 | ||
ef16cc59 N |
451 | if (rcu_walk) { |
452 | /* We don't need fs_lock in rcu_walk mode, | |
453 | * just testing 'AUTOFS_INFO_NO_RCU' is enough. | |
454 | * simple_empty() takes a spinlock, so leave it | |
455 | * to last. | |
456 | * We only return -EISDIR when certain this isn't | |
457 | * a mount-trap. | |
23bfc2a2 | 458 | */ |
ef16cc59 | 459 | struct inode *inode; |
e9a7c2f1 | 460 | |
ef16cc59 N |
461 | if (ino->flags & (AUTOFS_INF_EXPIRING | AUTOFS_INF_NO_RCU)) |
462 | return 0; | |
463 | if (d_mountpoint(dentry)) | |
464 | return 0; | |
2b0143b5 | 465 | inode = d_inode_rcu(dentry); |
ef16cc59 N |
466 | if (inode && S_ISLNK(inode->i_mode)) |
467 | return -EISDIR; | |
468 | if (list_empty(&dentry->d_subdirs)) | |
469 | return 0; | |
470 | if (!simple_empty(dentry)) | |
471 | return -EISDIR; | |
23bfc2a2 | 472 | return 0; |
ef16cc59 | 473 | } |
23bfc2a2 | 474 | |
f55fb0c2 IK |
475 | spin_lock(&sbi->fs_lock); |
476 | /* | |
477 | * If the dentry has been selected for expire while we slept | |
478 | * on the lock then it might go away. We'll deal with that in | |
479 | * ->d_automount() and wait on a new mount if the expire | |
480 | * succeeds or return here if it doesn't (since there's no | |
481 | * mount to follow with a rootless multi-mount). | |
482 | */ | |
483 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { | |
484 | /* | |
485 | * Any needed mounting has been completed and the path | |
486 | * updated so check if this is a rootless multi-mount so | |
487 | * we can avoid needless calls ->d_automount() and avoid | |
488 | * an incorrect ELOOP error return. | |
489 | */ | |
490 | if ((!d_mountpoint(dentry) && !simple_empty(dentry)) || | |
2b0143b5 | 491 | (d_really_is_positive(dentry) && d_is_symlink(dentry))) |
f55fb0c2 IK |
492 | status = -EISDIR; |
493 | } | |
494 | spin_unlock(&sbi->fs_lock); | |
495 | ||
496 | return status; | |
b5b80177 IK |
497 | } |
498 | ||
1da177e4 | 499 | /* Lookups in the root directory */ |
e9a7c2f1 IK |
500 | static struct dentry *autofs4_lookup(struct inode *dir, |
501 | struct dentry *dentry, unsigned int flags) | |
1da177e4 LT |
502 | { |
503 | struct autofs_sb_info *sbi; | |
25767378 | 504 | struct autofs_info *ino; |
10584211 | 505 | struct dentry *active; |
1da177e4 | 506 | |
8a78d593 | 507 | pr_debug("name = %pd\n", dentry); |
1da177e4 | 508 | |
718c604a | 509 | /* File name too long to exist */ |
1da177e4 | 510 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 511 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
512 | |
513 | sbi = autofs4_sbi(dir->i_sb); | |
718c604a | 514 | |
8a78d593 IK |
515 | pr_debug("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n", |
516 | current->pid, task_pgrp_nr(current), sbi->catatonic, | |
517 | autofs4_oz_mode(sbi)); | |
1da177e4 | 518 | |
6510c9d8 | 519 | active = autofs4_lookup_active(dentry); |
e9a7c2f1 | 520 | if (active) |
10584211 | 521 | return active; |
e9a7c2f1 | 522 | else { |
4b1ae27a | 523 | /* |
10584211 IK |
524 | * A dentry that is not within the root can never trigger a |
525 | * mount operation, unless the directory already exists, so we | |
526 | * can return fail immediately. The daemon however does need | |
527 | * to create directories within the file system. | |
4b1ae27a | 528 | */ |
10584211 IK |
529 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
530 | return ERR_PTR(-ENOENT); | |
531 | ||
532 | /* Mark entries in the root as mount triggers */ | |
e9a7c2f1 IK |
533 | if (IS_ROOT(dentry->d_parent) && |
534 | autofs_type_indirect(sbi->type)) | |
b5b80177 | 535 | __managed_dentry_set_managed(dentry); |
10584211 | 536 | |
26e6c910 | 537 | ino = autofs4_new_ino(sbi); |
4b1ae27a AV |
538 | if (!ino) |
539 | return ERR_PTR(-ENOMEM); | |
540 | ||
541 | dentry->d_fsdata = ino; | |
542 | ino->dentry = dentry; | |
5f6f4f28 | 543 | |
4b1ae27a | 544 | autofs4_add_active(dentry); |
4b1ae27a | 545 | } |
1da177e4 LT |
546 | return NULL; |
547 | } | |
548 | ||
549 | static int autofs4_dir_symlink(struct inode *dir, | |
550 | struct dentry *dentry, | |
551 | const char *symname) | |
552 | { | |
553 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
554 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 555 | struct autofs_info *p_ino; |
1da177e4 | 556 | struct inode *inode; |
0bf71d4d | 557 | size_t size = strlen(symname); |
1da177e4 LT |
558 | char *cp; |
559 | ||
8a78d593 | 560 | pr_debug("%s <- %pd\n", symname, dentry); |
1da177e4 LT |
561 | |
562 | if (!autofs4_oz_mode(sbi)) | |
563 | return -EACCES; | |
564 | ||
5a37db30 AV |
565 | BUG_ON(!ino); |
566 | ||
26e6c910 | 567 | autofs4_clean_ino(ino); |
1da177e4 | 568 | |
4b1ae27a AV |
569 | autofs4_del_active(dentry); |
570 | ||
0bf71d4d | 571 | cp = kmalloc(size + 1, GFP_KERNEL); |
5a37db30 | 572 | if (!cp) |
25767378 | 573 | return -ENOMEM; |
1da177e4 LT |
574 | |
575 | strcpy(cp, symname); | |
576 | ||
726a5e06 | 577 | inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555); |
25767378 IK |
578 | if (!inode) { |
579 | kfree(cp); | |
580 | if (!dentry->d_fsdata) | |
581 | kfree(ino); | |
582 | return -ENOMEM; | |
583 | } | |
292c5ee8 | 584 | inode->i_private = cp; |
0bf71d4d | 585 | inode->i_size = size; |
1864f7bd | 586 | d_add(dentry, inode); |
1da177e4 | 587 | |
5a37db30 | 588 | dget(dentry); |
1aff3c8b IK |
589 | atomic_inc(&ino->count); |
590 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 591 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 592 | atomic_inc(&p_ino->count); |
1da177e4 LT |
593 | |
594 | dir->i_mtime = CURRENT_TIME; | |
595 | ||
596 | return 0; | |
597 | } | |
598 | ||
599 | /* | |
600 | * NOTE! | |
601 | * | |
602 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
603 | * that the file no longer exists. However, doing that means that the | |
604 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 605 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
606 | * We simply d_drop it and add it to a expiring list in the super block, |
607 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
608 | * |
609 | * If a process is blocked on the dentry waiting for the expire to finish, | |
610 | * it will invalidate the dentry and try to mount with a new one. | |
611 | * | |
612 | * Also see autofs4_dir_rmdir().. | |
613 | */ | |
614 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
615 | { | |
616 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
617 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 618 | struct autofs_info *p_ino; |
0266725a | 619 | |
1da177e4 | 620 | /* This allows root to remove symlinks */ |
d78e53c8 | 621 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
41735818 | 622 | return -EPERM; |
1da177e4 | 623 | |
1aff3c8b IK |
624 | if (atomic_dec_and_test(&ino->count)) { |
625 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 626 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b IK |
627 | atomic_dec(&p_ino->count); |
628 | } | |
1da177e4 LT |
629 | dput(ino->dentry); |
630 | ||
2b0143b5 DH |
631 | d_inode(dentry)->i_size = 0; |
632 | clear_nlink(d_inode(dentry)); | |
1da177e4 LT |
633 | |
634 | dir->i_mtime = CURRENT_TIME; | |
635 | ||
e7854723 IK |
636 | spin_lock(&sbi->lookup_lock); |
637 | __autofs4_add_expiring(dentry); | |
0259cb02 | 638 | d_drop(dentry); |
e7854723 | 639 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
640 | |
641 | return 0; | |
642 | } | |
643 | ||
dd89f90d IK |
644 | /* |
645 | * Version 4 of autofs provides a pseudo direct mount implementation | |
646 | * that relies on directories at the leaves of a directory tree under | |
647 | * an indirect mount to trigger mounts. To allow for this we need to | |
648 | * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves | |
649 | * of the directory tree. There is no need to clear the automount flag | |
650 | * following a mount or restore it after an expire because these mounts | |
25985edc | 651 | * are always covered. However, it is necessary to ensure that these |
dd89f90d IK |
652 | * flags are clear on non-empty directories to avoid unnecessary calls |
653 | * during path walks. | |
654 | */ | |
655 | static void autofs_set_leaf_automount_flags(struct dentry *dentry) | |
656 | { | |
657 | struct dentry *parent; | |
658 | ||
659 | /* root and dentrys in the root are already handled */ | |
660 | if (IS_ROOT(dentry->d_parent)) | |
661 | return; | |
662 | ||
663 | managed_dentry_set_managed(dentry); | |
664 | ||
665 | parent = dentry->d_parent; | |
666 | /* only consider parents below dentrys in the root */ | |
667 | if (IS_ROOT(parent->d_parent)) | |
668 | return; | |
669 | managed_dentry_clear_managed(parent); | |
dd89f90d IK |
670 | } |
671 | ||
672 | static void autofs_clear_leaf_automount_flags(struct dentry *dentry) | |
673 | { | |
674 | struct list_head *d_child; | |
675 | struct dentry *parent; | |
676 | ||
677 | /* flags for dentrys in the root are handled elsewhere */ | |
678 | if (IS_ROOT(dentry->d_parent)) | |
679 | return; | |
680 | ||
681 | managed_dentry_clear_managed(dentry); | |
682 | ||
683 | parent = dentry->d_parent; | |
684 | /* only consider parents below dentrys in the root */ | |
685 | if (IS_ROOT(parent->d_parent)) | |
686 | return; | |
946e51f2 | 687 | d_child = &dentry->d_child; |
dd89f90d IK |
688 | /* Set parent managed if it's becoming empty */ |
689 | if (d_child->next == &parent->d_subdirs && | |
690 | d_child->prev == &parent->d_subdirs) | |
691 | managed_dentry_set_managed(parent); | |
dd89f90d IK |
692 | } |
693 | ||
1da177e4 LT |
694 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
695 | { | |
696 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
697 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 698 | struct autofs_info *p_ino; |
0266725a | 699 | |
8a78d593 | 700 | pr_debug("dentry %p, removing %pd\n", dentry, dentry); |
f50b6f86 | 701 | |
1da177e4 LT |
702 | if (!autofs4_oz_mode(sbi)) |
703 | return -EACCES; | |
704 | ||
2fd6b7f5 | 705 | spin_lock(&sbi->lookup_lock); |
0259cb02 | 706 | if (!simple_empty(dentry)) { |
2fd6b7f5 | 707 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
708 | return -ENOTEMPTY; |
709 | } | |
2fd6b7f5 | 710 | __autofs4_add_expiring(dentry); |
0259cb02 | 711 | d_drop(dentry); |
e7854723 | 712 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 713 | |
dd89f90d IK |
714 | if (sbi->version < 5) |
715 | autofs_clear_leaf_automount_flags(dentry); | |
716 | ||
1aff3c8b IK |
717 | if (atomic_dec_and_test(&ino->count)) { |
718 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
719 | if (p_ino && dentry->d_parent != dentry) | |
720 | atomic_dec(&p_ino->count); | |
721 | } | |
1da177e4 | 722 | dput(ino->dentry); |
2b0143b5 DH |
723 | d_inode(dentry)->i_size = 0; |
724 | clear_nlink(d_inode(dentry)); | |
1da177e4 LT |
725 | |
726 | if (dir->i_nlink) | |
9a53c3a7 | 727 | drop_nlink(dir); |
1da177e4 LT |
728 | |
729 | return 0; | |
730 | } | |
731 | ||
e9a7c2f1 IK |
732 | static int autofs4_dir_mkdir(struct inode *dir, |
733 | struct dentry *dentry, umode_t mode) | |
1da177e4 LT |
734 | { |
735 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
736 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 737 | struct autofs_info *p_ino; |
1da177e4 LT |
738 | struct inode *inode; |
739 | ||
d78e53c8 | 740 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
741 | return -EACCES; |
742 | ||
8a78d593 | 743 | pr_debug("dentry %p, creating %pd\n", dentry, dentry); |
1da177e4 | 744 | |
5a37db30 AV |
745 | BUG_ON(!ino); |
746 | ||
26e6c910 | 747 | autofs4_clean_ino(ino); |
25767378 | 748 | |
4b1ae27a AV |
749 | autofs4_del_active(dentry); |
750 | ||
726a5e06 | 751 | inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555); |
5a37db30 | 752 | if (!inode) |
25767378 | 753 | return -ENOMEM; |
1864f7bd | 754 | d_add(dentry, inode); |
1da177e4 | 755 | |
dd89f90d IK |
756 | if (sbi->version < 5) |
757 | autofs_set_leaf_automount_flags(dentry); | |
758 | ||
5a37db30 | 759 | dget(dentry); |
1aff3c8b IK |
760 | atomic_inc(&ino->count); |
761 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 762 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 763 | atomic_inc(&p_ino->count); |
d8c76e6f | 764 | inc_nlink(dir); |
1da177e4 LT |
765 | dir->i_mtime = CURRENT_TIME; |
766 | ||
767 | return 0; | |
768 | } | |
769 | ||
770 | /* Get/set timeout ioctl() operation */ | |
c9243f5b AB |
771 | #ifdef CONFIG_COMPAT |
772 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, | |
e9a7c2f1 | 773 | compat_ulong_t __user *p) |
c9243f5b | 774 | { |
c9243f5b | 775 | unsigned long ntimeout; |
aa330ddc IK |
776 | int rv; |
777 | ||
778 | rv = get_user(ntimeout, p); | |
779 | if (rv) | |
780 | goto error; | |
c9243f5b | 781 | |
aa330ddc IK |
782 | rv = put_user(sbi->exp_timeout/HZ, p); |
783 | if (rv) | |
784 | goto error; | |
c9243f5b AB |
785 | |
786 | if (ntimeout > UINT_MAX/HZ) | |
787 | sbi->exp_timeout = 0; | |
788 | else | |
789 | sbi->exp_timeout = ntimeout * HZ; | |
790 | ||
791 | return 0; | |
aa330ddc IK |
792 | error: |
793 | return rv; | |
c9243f5b AB |
794 | } |
795 | #endif | |
796 | ||
1da177e4 | 797 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
e9a7c2f1 | 798 | unsigned long __user *p) |
1da177e4 | 799 | { |
1da177e4 | 800 | unsigned long ntimeout; |
aa330ddc IK |
801 | int rv; |
802 | ||
803 | rv = get_user(ntimeout, p); | |
804 | if (rv) | |
805 | goto error; | |
1da177e4 | 806 | |
aa330ddc IK |
807 | rv = put_user(sbi->exp_timeout/HZ, p); |
808 | if (rv) | |
809 | goto error; | |
1da177e4 | 810 | |
d78e53c8 | 811 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
812 | sbi->exp_timeout = 0; |
813 | else | |
814 | sbi->exp_timeout = ntimeout * HZ; | |
815 | ||
816 | return 0; | |
aa330ddc IK |
817 | error: |
818 | return rv; | |
1da177e4 LT |
819 | } |
820 | ||
821 | /* Return protocol version */ | |
e9a7c2f1 IK |
822 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, |
823 | int __user *p) | |
1da177e4 LT |
824 | { |
825 | return put_user(sbi->version, p); | |
826 | } | |
827 | ||
828 | /* Return protocol sub version */ | |
e9a7c2f1 IK |
829 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, |
830 | int __user *p) | |
1da177e4 LT |
831 | { |
832 | return put_user(sbi->sub_version, p); | |
833 | } | |
834 | ||
1da177e4 LT |
835 | /* |
836 | * Tells the daemon whether it can umount the autofs mount. | |
837 | */ | |
838 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
839 | { | |
840 | int status = 0; | |
841 | ||
e3474a8e | 842 | if (may_umount(mnt)) |
1da177e4 LT |
843 | status = 1; |
844 | ||
8a78d593 | 845 | pr_debug("returning %d\n", status); |
1da177e4 LT |
846 | |
847 | status = put_user(status, p); | |
848 | ||
849 | return status; | |
850 | } | |
851 | ||
852 | /* Identify autofs4_dentries - this is so we can tell if there's | |
e9a7c2f1 IK |
853 | * an extra dentry refcount or not. We only hold a refcount on the |
854 | * dentry if its non-negative (ie, d_inode != NULL) | |
855 | */ | |
1da177e4 LT |
856 | int is_autofs4_dentry(struct dentry *dentry) |
857 | { | |
2b0143b5 | 858 | return dentry && d_really_is_positive(dentry) && |
b650c858 | 859 | dentry->d_op == &autofs4_dentry_operations && |
1da177e4 LT |
860 | dentry->d_fsdata != NULL; |
861 | } | |
862 | ||
863 | /* | |
864 | * ioctl()'s on the root directory is the chief method for the daemon to | |
865 | * generate kernel reactions | |
866 | */ | |
3663df70 FW |
867 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
868 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
869 | { |
870 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
871 | void __user *p = (void __user *)arg; | |
872 | ||
8a78d593 IK |
873 | pr_debug("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n", |
874 | cmd, arg, sbi, task_pgrp_nr(current)); | |
1da177e4 | 875 | |
d78e53c8 SB |
876 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
877 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 | 878 | return -ENOTTY; |
0266725a | 879 | |
d78e53c8 | 880 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 | 881 | return -EPERM; |
0266725a | 882 | |
e9a7c2f1 | 883 | switch (cmd) { |
1da177e4 | 884 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ |
e9a7c2f1 | 885 | return autofs4_wait_release(sbi, (autofs_wqt_t) arg, 0); |
1da177e4 | 886 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ |
e9a7c2f1 | 887 | return autofs4_wait_release(sbi, (autofs_wqt_t) arg, -ENOENT); |
1da177e4 LT |
888 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ |
889 | autofs4_catatonic_mode(sbi); | |
890 | return 0; | |
891 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
892 | return autofs4_get_protover(sbi, p); | |
893 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
894 | return autofs4_get_protosubver(sbi, p); | |
895 | case AUTOFS_IOC_SETTIMEOUT: | |
896 | return autofs4_get_set_timeout(sbi, p); | |
c9243f5b AB |
897 | #ifdef CONFIG_COMPAT |
898 | case AUTOFS_IOC_SETTIMEOUT32: | |
899 | return autofs4_compat_get_set_timeout(sbi, p); | |
900 | #endif | |
1da177e4 | 901 | |
1da177e4 | 902 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 903 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
904 | |
905 | /* return a single thing to expire */ | |
906 | case AUTOFS_IOC_EXPIRE: | |
e9a7c2f1 IK |
907 | return autofs4_expire_run(inode->i_sb, |
908 | filp->f_path.mnt, sbi, p); | |
1da177e4 LT |
909 | /* same as above, but can send multiple expires through pipe */ |
910 | case AUTOFS_IOC_EXPIRE_MULTI: | |
e9a7c2f1 IK |
911 | return autofs4_expire_multi(inode->i_sb, |
912 | filp->f_path.mnt, sbi, p); | |
1da177e4 LT |
913 | |
914 | default: | |
e3cd8067 | 915 | return -EINVAL; |
1da177e4 LT |
916 | } |
917 | } | |
3663df70 FW |
918 | |
919 | static long autofs4_root_ioctl(struct file *filp, | |
920 | unsigned int cmd, unsigned long arg) | |
921 | { | |
496ad9aa | 922 | struct inode *inode = file_inode(filp); |
e9a7c2f1 | 923 | |
de47de74 | 924 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
3663df70 | 925 | } |
c9243f5b AB |
926 | |
927 | #ifdef CONFIG_COMPAT | |
928 | static long autofs4_root_compat_ioctl(struct file *filp, | |
e9a7c2f1 | 929 | unsigned int cmd, unsigned long arg) |
c9243f5b | 930 | { |
496ad9aa | 931 | struct inode *inode = file_inode(filp); |
c9243f5b AB |
932 | int ret; |
933 | ||
c9243f5b AB |
934 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
935 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); | |
936 | else | |
937 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, | |
e9a7c2f1 | 938 | (unsigned long) compat_ptr(arg)); |
c9243f5b AB |
939 | |
940 | return ret; | |
941 | } | |
942 | #endif |