Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* -*- c -*- --------------------------------------------------------------- * |
2 | * | |
3 | * linux/fs/autofs/root.c | |
4 | * | |
5 | * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved | |
6 | * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> | |
34ca959c | 7 | * Copyright 2001-2006 Ian Kent <raven@themaw.net> |
1da177e4 LT |
8 | * |
9 | * This file is part of the Linux kernel and is made available under | |
10 | * the terms of the GNU General Public License, version 2, or at your | |
11 | * option, any later version, incorporated herein by reference. | |
12 | * | |
13 | * ------------------------------------------------------------------------- */ | |
14 | ||
16f7e0fe | 15 | #include <linux/capability.h> |
1da177e4 LT |
16 | #include <linux/errno.h> |
17 | #include <linux/stat.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
1da177e4 LT |
19 | #include <linux/param.h> |
20 | #include <linux/time.h> | |
c9243f5b | 21 | #include <linux/compat.h> |
00e300e1 | 22 | #include <linux/mutex.h> |
c9243f5b | 23 | |
1da177e4 LT |
24 | #include "autofs_i.h" |
25 | ||
26 | static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); | |
27 | static int autofs4_dir_unlink(struct inode *,struct dentry *); | |
28 | static int autofs4_dir_rmdir(struct inode *,struct dentry *); | |
18bb1db3 | 29 | static int autofs4_dir_mkdir(struct inode *,struct dentry *,umode_t); |
3663df70 | 30 | static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long); |
5a44a73b | 31 | #ifdef CONFIG_COMPAT |
c9243f5b | 32 | static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long); |
5a44a73b | 33 | #endif |
1da177e4 | 34 | static int autofs4_dir_open(struct inode *inode, struct file *file); |
00cd8dd3 | 35 | static struct dentry *autofs4_lookup(struct inode *,struct dentry *, unsigned int); |
71e469db | 36 | static struct vfsmount *autofs4_d_automount(struct path *); |
1aed3e42 | 37 | static int autofs4_d_manage(struct dentry *, bool); |
b89b12b4 | 38 | static void autofs4_dentry_release(struct dentry *); |
1da177e4 | 39 | |
4b6f5d20 | 40 | const struct file_operations autofs4_root_operations = { |
1da177e4 LT |
41 | .open = dcache_dir_open, |
42 | .release = dcache_dir_close, | |
43 | .read = generic_read_dir, | |
5f99f4e7 | 44 | .iterate = dcache_readdir, |
59af1584 | 45 | .llseek = dcache_dir_lseek, |
3663df70 | 46 | .unlocked_ioctl = autofs4_root_ioctl, |
c9243f5b AB |
47 | #ifdef CONFIG_COMPAT |
48 | .compat_ioctl = autofs4_root_compat_ioctl, | |
49 | #endif | |
1da177e4 LT |
50 | }; |
51 | ||
4b6f5d20 | 52 | const struct file_operations autofs4_dir_operations = { |
1da177e4 | 53 | .open = autofs4_dir_open, |
ff9cd499 | 54 | .release = dcache_dir_close, |
1da177e4 | 55 | .read = generic_read_dir, |
5f99f4e7 | 56 | .iterate = dcache_readdir, |
59af1584 | 57 | .llseek = dcache_dir_lseek, |
1da177e4 LT |
58 | }; |
59 | ||
754661f1 | 60 | const struct inode_operations autofs4_dir_inode_operations = { |
1da177e4 LT |
61 | .lookup = autofs4_lookup, |
62 | .unlink = autofs4_dir_unlink, | |
63 | .symlink = autofs4_dir_symlink, | |
64 | .mkdir = autofs4_dir_mkdir, | |
65 | .rmdir = autofs4_dir_rmdir, | |
66 | }; | |
67 | ||
71e469db | 68 | const struct dentry_operations autofs4_dentry_operations = { |
71e469db IK |
69 | .d_automount = autofs4_d_automount, |
70 | .d_manage = autofs4_d_manage, | |
71 | .d_release = autofs4_dentry_release, | |
72 | }; | |
73 | ||
4f8427d1 IK |
74 | static void autofs4_add_active(struct dentry *dentry) |
75 | { | |
76 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
77 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
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 | } | |
87 | return; | |
88 | } | |
89 | ||
90 | static void autofs4_del_active(struct dentry *dentry) | |
91 | { | |
92 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
93 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
94 | if (ino) { | |
95 | spin_lock(&sbi->lookup_lock); | |
96 | ino->active_count--; | |
97 | if (!ino->active_count) { | |
98 | if (!list_empty(&ino->active)) | |
99 | list_del_init(&ino->active); | |
100 | } | |
101 | spin_unlock(&sbi->lookup_lock); | |
102 | } | |
103 | return; | |
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 | |
1da177e4 LT |
111 | DPRINTK("file=%p dentry=%p %.*s", |
112 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
113 | ||
114 | if (autofs4_oz_mode(sbi)) | |
115 | goto out; | |
116 | ||
ff9cd499 IK |
117 | /* |
118 | * An empty directory in an autofs file system is always a | |
119 | * mount point. The daemon must have failed to mount this | |
120 | * during lookup so it doesn't exist. This can happen, for | |
121 | * example, if user space returns an incorrect status for a | |
122 | * mount request. Otherwise we're doing a readdir on the | |
123 | * autofs file system so just let the libfs routines handle | |
124 | * it. | |
125 | */ | |
e7854723 | 126 | spin_lock(&sbi->lookup_lock); |
0259cb02 | 127 | if (!d_mountpoint(dentry) && simple_empty(dentry)) { |
e7854723 | 128 | spin_unlock(&sbi->lookup_lock); |
ff9cd499 | 129 | return -ENOENT; |
1da177e4 | 130 | } |
e7854723 | 131 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 132 | |
1da177e4 | 133 | out: |
ff9cd499 | 134 | return dcache_dir_open(inode, file); |
1da177e4 LT |
135 | } |
136 | ||
b89b12b4 | 137 | static void autofs4_dentry_release(struct dentry *de) |
1da177e4 | 138 | { |
b89b12b4 AV |
139 | struct autofs_info *ino = autofs4_dentry_ino(de); |
140 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); | |
1da177e4 LT |
141 | |
142 | DPRINTK("releasing %p", de); | |
143 | ||
b89b12b4 AV |
144 | if (!ino) |
145 | return; | |
146 | ||
147 | if (sbi) { | |
148 | spin_lock(&sbi->lookup_lock); | |
149 | if (!list_empty(&ino->active)) | |
150 | list_del(&ino->active); | |
151 | if (!list_empty(&ino->expiring)) | |
152 | list_del(&ino->expiring); | |
153 | spin_unlock(&sbi->lookup_lock); | |
1da177e4 | 154 | } |
b89b12b4 AV |
155 | |
156 | autofs4_free_ino(ino); | |
1da177e4 LT |
157 | } |
158 | ||
6510c9d8 | 159 | static struct dentry *autofs4_lookup_active(struct dentry *dentry) |
25767378 | 160 | { |
6510c9d8 IK |
161 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
162 | struct dentry *parent = dentry->d_parent; | |
163 | struct qstr *name = &dentry->d_name; | |
25767378 IK |
164 | unsigned int len = name->len; |
165 | unsigned int hash = name->hash; | |
166 | const unsigned char *str = name->name; | |
167 | struct list_head *p, *head; | |
168 | ||
25767378 | 169 | head = &sbi->active_list; |
668128e9 N |
170 | if (list_empty(head)) |
171 | return NULL; | |
172 | spin_lock(&sbi->lookup_lock); | |
25767378 IK |
173 | list_for_each(p, head) { |
174 | struct autofs_info *ino; | |
e4d5ade7 | 175 | struct dentry *active; |
25767378 IK |
176 | struct qstr *qstr; |
177 | ||
178 | ino = list_entry(p, struct autofs_info, active); | |
e4d5ade7 | 179 | active = ino->dentry; |
25767378 | 180 | |
e4d5ade7 | 181 | spin_lock(&active->d_lock); |
25767378 IK |
182 | |
183 | /* Already gone? */ | |
6b6751f7 | 184 | if ((int) d_count(active) <= 0) |
25767378 IK |
185 | goto next; |
186 | ||
e4d5ade7 | 187 | qstr = &active->d_name; |
25767378 | 188 | |
e4d5ade7 | 189 | if (active->d_name.hash != hash) |
25767378 | 190 | goto next; |
e4d5ade7 | 191 | if (active->d_parent != parent) |
25767378 IK |
192 | goto next; |
193 | ||
194 | if (qstr->len != len) | |
195 | goto next; | |
196 | if (memcmp(qstr->name, str, len)) | |
197 | goto next; | |
198 | ||
4b1ae27a | 199 | if (d_unhashed(active)) { |
b7ab39f6 | 200 | dget_dlock(active); |
4b1ae27a AV |
201 | spin_unlock(&active->d_lock); |
202 | spin_unlock(&sbi->lookup_lock); | |
4b1ae27a AV |
203 | return active; |
204 | } | |
25767378 | 205 | next: |
e4d5ade7 | 206 | spin_unlock(&active->d_lock); |
25767378 IK |
207 | } |
208 | spin_unlock(&sbi->lookup_lock); | |
25767378 IK |
209 | |
210 | return NULL; | |
211 | } | |
212 | ||
6510c9d8 | 213 | static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) |
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 | ||
5f6f4f28 | 232 | ino = list_entry(p, struct autofs_info, expiring); |
cb4b492a | 233 | expiring = ino->dentry; |
f50b6f86 | 234 | |
cb4b492a | 235 | spin_lock(&expiring->d_lock); |
f50b6f86 | 236 | |
6b6751f7 | 237 | /* We've already been dentry_iput or unlinked */ |
cb4b492a | 238 | if (!expiring->d_inode) |
f50b6f86 IK |
239 | goto next; |
240 | ||
cb4b492a | 241 | qstr = &expiring->d_name; |
f50b6f86 | 242 | |
cb4b492a | 243 | if (expiring->d_name.hash != hash) |
f50b6f86 | 244 | goto next; |
cb4b492a | 245 | if (expiring->d_parent != parent) |
f50b6f86 IK |
246 | goto next; |
247 | ||
248 | if (qstr->len != len) | |
249 | goto next; | |
250 | if (memcmp(qstr->name, str, len)) | |
251 | goto next; | |
252 | ||
4b1ae27a | 253 | if (d_unhashed(expiring)) { |
b7ab39f6 | 254 | dget_dlock(expiring); |
4b1ae27a AV |
255 | spin_unlock(&expiring->d_lock); |
256 | spin_unlock(&sbi->lookup_lock); | |
4b1ae27a AV |
257 | return expiring; |
258 | } | |
f50b6f86 | 259 | next: |
cb4b492a | 260 | spin_unlock(&expiring->d_lock); |
f50b6f86 | 261 | } |
5f6f4f28 | 262 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
263 | |
264 | return NULL; | |
265 | } | |
266 | ||
10584211 IK |
267 | static int autofs4_mount_wait(struct dentry *dentry) |
268 | { | |
269 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
270 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
3c319985 | 271 | int status = 0; |
10584211 IK |
272 | |
273 | if (ino->flags & AUTOFS_INF_PENDING) { | |
274 | DPRINTK("waiting for mount name=%.*s", | |
275 | dentry->d_name.len, dentry->d_name.name); | |
276 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
277 | DPRINTK("mount wait done status=%d", status); | |
10584211 | 278 | } |
3c319985 IK |
279 | ino->last_used = jiffies; |
280 | return status; | |
10584211 IK |
281 | } |
282 | ||
283 | static int do_expire_wait(struct dentry *dentry) | |
284 | { | |
285 | struct dentry *expiring; | |
286 | ||
287 | expiring = autofs4_lookup_expiring(dentry); | |
288 | if (!expiring) | |
289 | return autofs4_expire_wait(dentry); | |
290 | else { | |
291 | /* | |
292 | * If we are racing with expire the request might not | |
293 | * be quite complete, but the directory has been removed | |
294 | * so it must have been successful, just wait for it. | |
295 | */ | |
296 | autofs4_expire_wait(expiring); | |
297 | autofs4_del_expiring(expiring); | |
298 | dput(expiring); | |
299 | } | |
300 | return 0; | |
301 | } | |
302 | ||
303 | static struct dentry *autofs4_mountpoint_changed(struct path *path) | |
304 | { | |
305 | struct dentry *dentry = path->dentry; | |
306 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
307 | ||
308 | /* | |
309 | * If this is an indirect mount the dentry could have gone away | |
310 | * as a result of an expire and a new one created. | |
311 | */ | |
312 | if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { | |
313 | struct dentry *parent = dentry->d_parent; | |
3c319985 | 314 | struct autofs_info *ino; |
10584211 IK |
315 | struct dentry *new = d_lookup(parent, &dentry->d_name); |
316 | if (!new) | |
317 | return NULL; | |
3c319985 IK |
318 | ino = autofs4_dentry_ino(new); |
319 | ino->last_used = jiffies; | |
10584211 IK |
320 | dput(path->dentry); |
321 | path->dentry = new; | |
322 | } | |
323 | return path->dentry; | |
324 | } | |
325 | ||
71e469db | 326 | static struct vfsmount *autofs4_d_automount(struct path *path) |
10584211 IK |
327 | { |
328 | struct dentry *dentry = path->dentry; | |
329 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
330 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
331 | int status; | |
332 | ||
333 | DPRINTK("dentry=%p %.*s", | |
334 | dentry, dentry->d_name.len, dentry->d_name.name); | |
335 | ||
336 | /* The daemon never triggers a mount. */ | |
337 | if (autofs4_oz_mode(sbi)) | |
338 | return NULL; | |
339 | ||
340 | /* | |
341 | * If an expire request is pending everyone must wait. | |
342 | * If the expire fails we're still mounted so continue | |
343 | * the follow and return. A return of -EAGAIN (which only | |
344 | * happens with indirect mounts) means the expire completed | |
345 | * and the directory was removed, so just go ahead and try | |
346 | * the mount. | |
347 | */ | |
348 | status = do_expire_wait(dentry); | |
349 | if (status && status != -EAGAIN) | |
350 | return NULL; | |
351 | ||
352 | /* Callback to the daemon to perform the mount or wait */ | |
353 | spin_lock(&sbi->fs_lock); | |
354 | if (ino->flags & AUTOFS_INF_PENDING) { | |
355 | spin_unlock(&sbi->fs_lock); | |
356 | status = autofs4_mount_wait(dentry); | |
357 | if (status) | |
358 | return ERR_PTR(status); | |
10584211 IK |
359 | goto done; |
360 | } | |
361 | ||
362 | /* | |
363 | * If the dentry is a symlink it's equivalent to a directory | |
b5b80177 | 364 | * having d_mountpoint() true, so there's no need to call back |
10584211 IK |
365 | * to the daemon. |
366 | */ | |
f55fb0c2 IK |
367 | if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) { |
368 | spin_unlock(&sbi->fs_lock); | |
10584211 | 369 | goto done; |
f55fb0c2 IK |
370 | } |
371 | ||
b5b80177 IK |
372 | if (!d_mountpoint(dentry)) { |
373 | /* | |
374 | * It's possible that user space hasn't removed directories | |
375 | * after umounting a rootless multi-mount, although it | |
376 | * should. For v5 have_submounts() is sufficient to handle | |
377 | * this because the leaves of the directory tree under the | |
378 | * mount never trigger mounts themselves (they have an autofs | |
379 | * trigger mount mounted on them). But v4 pseudo direct mounts | |
3b97dd05 | 380 | * do need the leaves to trigger mounts. In this case we |
b5b80177 IK |
381 | * have no choice but to use the list_empty() check and |
382 | * require user space behave. | |
383 | */ | |
384 | if (sbi->version > 4) { | |
f55fb0c2 IK |
385 | if (have_submounts(dentry)) { |
386 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 387 | goto done; |
f55fb0c2 | 388 | } |
b5b80177 | 389 | } else { |
9d8072e7 PH |
390 | if (!simple_empty(dentry)) { |
391 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 392 | goto done; |
9d8072e7 | 393 | } |
b5b80177 | 394 | } |
10584211 | 395 | ino->flags |= AUTOFS_INF_PENDING; |
10584211 IK |
396 | spin_unlock(&sbi->fs_lock); |
397 | status = autofs4_mount_wait(dentry); | |
10584211 IK |
398 | spin_lock(&sbi->fs_lock); |
399 | ino->flags &= ~AUTOFS_INF_PENDING; | |
49999ab2 IK |
400 | if (status) { |
401 | spin_unlock(&sbi->fs_lock); | |
402 | return ERR_PTR(status); | |
403 | } | |
10584211 | 404 | } |
10584211 | 405 | spin_unlock(&sbi->fs_lock); |
f55fb0c2 | 406 | done: |
10584211 IK |
407 | /* Mount succeeded, check if we ended up with a new dentry */ |
408 | dentry = autofs4_mountpoint_changed(path); | |
409 | if (!dentry) | |
410 | return ERR_PTR(-ENOENT); | |
411 | ||
412 | return NULL; | |
413 | } | |
414 | ||
95482986 | 415 | static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk) |
b5b80177 IK |
416 | { |
417 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f55fb0c2 IK |
418 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
419 | int status; | |
b5b80177 IK |
420 | |
421 | DPRINTK("dentry=%p %.*s", | |
422 | dentry, dentry->d_name.len, dentry->d_name.name); | |
423 | ||
424 | /* The daemon never waits. */ | |
1aed3e42 | 425 | if (autofs4_oz_mode(sbi)) { |
83fb96bf IK |
426 | if (rcu_walk) |
427 | return 0; | |
b5b80177 IK |
428 | if (!d_mountpoint(dentry)) |
429 | return -EISDIR; | |
430 | return 0; | |
431 | } | |
432 | ||
ab90911f DH |
433 | /* We need to sleep, so we need pathwalk to be in ref-mode */ |
434 | if (rcu_walk) | |
435 | return -ECHILD; | |
436 | ||
b5b80177 IK |
437 | /* Wait for pending expires */ |
438 | do_expire_wait(dentry); | |
439 | ||
440 | /* | |
441 | * This dentry may be under construction so wait on mount | |
442 | * completion. | |
443 | */ | |
f55fb0c2 IK |
444 | status = autofs4_mount_wait(dentry); |
445 | if (status) | |
446 | return status; | |
447 | ||
448 | spin_lock(&sbi->fs_lock); | |
449 | /* | |
450 | * If the dentry has been selected for expire while we slept | |
451 | * on the lock then it might go away. We'll deal with that in | |
452 | * ->d_automount() and wait on a new mount if the expire | |
453 | * succeeds or return here if it doesn't (since there's no | |
454 | * mount to follow with a rootless multi-mount). | |
455 | */ | |
456 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { | |
457 | /* | |
458 | * Any needed mounting has been completed and the path | |
459 | * updated so check if this is a rootless multi-mount so | |
460 | * we can avoid needless calls ->d_automount() and avoid | |
461 | * an incorrect ELOOP error return. | |
462 | */ | |
463 | if ((!d_mountpoint(dentry) && !simple_empty(dentry)) || | |
464 | (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))) | |
465 | status = -EISDIR; | |
466 | } | |
467 | spin_unlock(&sbi->fs_lock); | |
468 | ||
469 | return status; | |
b5b80177 IK |
470 | } |
471 | ||
1da177e4 | 472 | /* Lookups in the root directory */ |
00cd8dd3 | 473 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 LT |
474 | { |
475 | struct autofs_sb_info *sbi; | |
25767378 | 476 | struct autofs_info *ino; |
10584211 | 477 | struct dentry *active; |
1da177e4 | 478 | |
10584211 | 479 | DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name); |
1da177e4 | 480 | |
718c604a | 481 | /* File name too long to exist */ |
1da177e4 | 482 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 483 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
484 | |
485 | sbi = autofs4_sbi(dir->i_sb); | |
718c604a | 486 | |
1da177e4 | 487 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
c0bcc9d5 IK |
488 | current->pid, task_pgrp_nr(current), sbi->catatonic, |
489 | autofs4_oz_mode(sbi)); | |
1da177e4 | 490 | |
6510c9d8 | 491 | active = autofs4_lookup_active(dentry); |
90387c9c | 492 | if (active) { |
10584211 | 493 | return active; |
aa952eb2 | 494 | } else { |
4b1ae27a | 495 | /* |
10584211 IK |
496 | * A dentry that is not within the root can never trigger a |
497 | * mount operation, unless the directory already exists, so we | |
498 | * can return fail immediately. The daemon however does need | |
499 | * to create directories within the file system. | |
4b1ae27a | 500 | */ |
10584211 IK |
501 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
502 | return ERR_PTR(-ENOENT); | |
503 | ||
504 | /* Mark entries in the root as mount triggers */ | |
b650c858 | 505 | if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) |
b5b80177 | 506 | __managed_dentry_set_managed(dentry); |
10584211 | 507 | |
26e6c910 | 508 | ino = autofs4_new_ino(sbi); |
4b1ae27a AV |
509 | if (!ino) |
510 | return ERR_PTR(-ENOMEM); | |
511 | ||
512 | dentry->d_fsdata = ino; | |
513 | ino->dentry = dentry; | |
5f6f4f28 | 514 | |
4b1ae27a AV |
515 | autofs4_add_active(dentry); |
516 | ||
517 | d_instantiate(dentry, NULL); | |
518 | } | |
1da177e4 LT |
519 | return NULL; |
520 | } | |
521 | ||
522 | static int autofs4_dir_symlink(struct inode *dir, | |
523 | struct dentry *dentry, | |
524 | const char *symname) | |
525 | { | |
526 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
527 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 528 | struct autofs_info *p_ino; |
1da177e4 | 529 | struct inode *inode; |
0bf71d4d | 530 | size_t size = strlen(symname); |
1da177e4 LT |
531 | char *cp; |
532 | ||
533 | DPRINTK("%s <- %.*s", symname, | |
534 | dentry->d_name.len, dentry->d_name.name); | |
535 | ||
536 | if (!autofs4_oz_mode(sbi)) | |
537 | return -EACCES; | |
538 | ||
5a37db30 AV |
539 | BUG_ON(!ino); |
540 | ||
26e6c910 | 541 | autofs4_clean_ino(ino); |
1da177e4 | 542 | |
4b1ae27a AV |
543 | autofs4_del_active(dentry); |
544 | ||
0bf71d4d | 545 | cp = kmalloc(size + 1, GFP_KERNEL); |
5a37db30 | 546 | if (!cp) |
25767378 | 547 | return -ENOMEM; |
1da177e4 LT |
548 | |
549 | strcpy(cp, symname); | |
550 | ||
726a5e06 | 551 | inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555); |
25767378 IK |
552 | if (!inode) { |
553 | kfree(cp); | |
554 | if (!dentry->d_fsdata) | |
555 | kfree(ino); | |
556 | return -ENOMEM; | |
557 | } | |
292c5ee8 | 558 | inode->i_private = cp; |
0bf71d4d | 559 | inode->i_size = size; |
1864f7bd | 560 | d_add(dentry, inode); |
1da177e4 | 561 | |
5a37db30 | 562 | dget(dentry); |
1aff3c8b IK |
563 | atomic_inc(&ino->count); |
564 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 565 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 566 | atomic_inc(&p_ino->count); |
1da177e4 LT |
567 | |
568 | dir->i_mtime = CURRENT_TIME; | |
569 | ||
570 | return 0; | |
571 | } | |
572 | ||
573 | /* | |
574 | * NOTE! | |
575 | * | |
576 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
577 | * that the file no longer exists. However, doing that means that the | |
578 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 579 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
580 | * We simply d_drop it and add it to a expiring list in the super block, |
581 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
582 | * |
583 | * If a process is blocked on the dentry waiting for the expire to finish, | |
584 | * it will invalidate the dentry and try to mount with a new one. | |
585 | * | |
586 | * Also see autofs4_dir_rmdir().. | |
587 | */ | |
588 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
589 | { | |
590 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
591 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 592 | struct autofs_info *p_ino; |
1da177e4 LT |
593 | |
594 | /* This allows root to remove symlinks */ | |
d78e53c8 | 595 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
41735818 | 596 | return -EPERM; |
1da177e4 | 597 | |
1aff3c8b IK |
598 | if (atomic_dec_and_test(&ino->count)) { |
599 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 600 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b IK |
601 | atomic_dec(&p_ino->count); |
602 | } | |
1da177e4 LT |
603 | dput(ino->dentry); |
604 | ||
605 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 606 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
607 | |
608 | dir->i_mtime = CURRENT_TIME; | |
609 | ||
e7854723 IK |
610 | spin_lock(&sbi->lookup_lock); |
611 | __autofs4_add_expiring(dentry); | |
0259cb02 | 612 | d_drop(dentry); |
e7854723 | 613 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
614 | |
615 | return 0; | |
616 | } | |
617 | ||
dd89f90d IK |
618 | /* |
619 | * Version 4 of autofs provides a pseudo direct mount implementation | |
620 | * that relies on directories at the leaves of a directory tree under | |
621 | * an indirect mount to trigger mounts. To allow for this we need to | |
622 | * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves | |
623 | * of the directory tree. There is no need to clear the automount flag | |
624 | * following a mount or restore it after an expire because these mounts | |
25985edc | 625 | * are always covered. However, it is necessary to ensure that these |
dd89f90d IK |
626 | * flags are clear on non-empty directories to avoid unnecessary calls |
627 | * during path walks. | |
628 | */ | |
629 | static void autofs_set_leaf_automount_flags(struct dentry *dentry) | |
630 | { | |
631 | struct dentry *parent; | |
632 | ||
633 | /* root and dentrys in the root are already handled */ | |
634 | if (IS_ROOT(dentry->d_parent)) | |
635 | return; | |
636 | ||
637 | managed_dentry_set_managed(dentry); | |
638 | ||
639 | parent = dentry->d_parent; | |
640 | /* only consider parents below dentrys in the root */ | |
641 | if (IS_ROOT(parent->d_parent)) | |
642 | return; | |
643 | managed_dentry_clear_managed(parent); | |
644 | return; | |
645 | } | |
646 | ||
647 | static void autofs_clear_leaf_automount_flags(struct dentry *dentry) | |
648 | { | |
649 | struct list_head *d_child; | |
650 | struct dentry *parent; | |
651 | ||
652 | /* flags for dentrys in the root are handled elsewhere */ | |
653 | if (IS_ROOT(dentry->d_parent)) | |
654 | return; | |
655 | ||
656 | managed_dentry_clear_managed(dentry); | |
657 | ||
658 | parent = dentry->d_parent; | |
659 | /* only consider parents below dentrys in the root */ | |
660 | if (IS_ROOT(parent->d_parent)) | |
661 | return; | |
662 | d_child = &dentry->d_u.d_child; | |
663 | /* Set parent managed if it's becoming empty */ | |
664 | if (d_child->next == &parent->d_subdirs && | |
665 | d_child->prev == &parent->d_subdirs) | |
666 | managed_dentry_set_managed(parent); | |
667 | return; | |
668 | } | |
669 | ||
1da177e4 LT |
670 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
671 | { | |
672 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
673 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 674 | struct autofs_info *p_ino; |
1da177e4 | 675 | |
f50b6f86 IK |
676 | DPRINTK("dentry %p, removing %.*s", |
677 | dentry, dentry->d_name.len, dentry->d_name.name); | |
678 | ||
1da177e4 LT |
679 | if (!autofs4_oz_mode(sbi)) |
680 | return -EACCES; | |
681 | ||
2fd6b7f5 | 682 | spin_lock(&sbi->lookup_lock); |
0259cb02 | 683 | if (!simple_empty(dentry)) { |
2fd6b7f5 | 684 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
685 | return -ENOTEMPTY; |
686 | } | |
2fd6b7f5 | 687 | __autofs4_add_expiring(dentry); |
0259cb02 | 688 | d_drop(dentry); |
e7854723 | 689 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 690 | |
dd89f90d IK |
691 | if (sbi->version < 5) |
692 | autofs_clear_leaf_automount_flags(dentry); | |
693 | ||
1aff3c8b IK |
694 | if (atomic_dec_and_test(&ino->count)) { |
695 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
696 | if (p_ino && dentry->d_parent != dentry) | |
697 | atomic_dec(&p_ino->count); | |
698 | } | |
1da177e4 | 699 | dput(ino->dentry); |
1da177e4 | 700 | dentry->d_inode->i_size = 0; |
ce71ec36 | 701 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
702 | |
703 | if (dir->i_nlink) | |
9a53c3a7 | 704 | drop_nlink(dir); |
1da177e4 LT |
705 | |
706 | return 0; | |
707 | } | |
708 | ||
18bb1db3 | 709 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
710 | { |
711 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
712 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 713 | struct autofs_info *p_ino; |
1da177e4 LT |
714 | struct inode *inode; |
715 | ||
d78e53c8 | 716 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
717 | return -EACCES; |
718 | ||
719 | DPRINTK("dentry %p, creating %.*s", | |
720 | dentry, dentry->d_name.len, dentry->d_name.name); | |
721 | ||
5a37db30 AV |
722 | BUG_ON(!ino); |
723 | ||
26e6c910 | 724 | autofs4_clean_ino(ino); |
25767378 | 725 | |
4b1ae27a AV |
726 | autofs4_del_active(dentry); |
727 | ||
726a5e06 | 728 | inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555); |
5a37db30 | 729 | if (!inode) |
25767378 | 730 | return -ENOMEM; |
1864f7bd | 731 | d_add(dentry, inode); |
1da177e4 | 732 | |
dd89f90d IK |
733 | if (sbi->version < 5) |
734 | autofs_set_leaf_automount_flags(dentry); | |
735 | ||
5a37db30 | 736 | dget(dentry); |
1aff3c8b IK |
737 | atomic_inc(&ino->count); |
738 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 739 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 740 | atomic_inc(&p_ino->count); |
d8c76e6f | 741 | inc_nlink(dir); |
1da177e4 LT |
742 | dir->i_mtime = CURRENT_TIME; |
743 | ||
744 | return 0; | |
745 | } | |
746 | ||
747 | /* Get/set timeout ioctl() operation */ | |
c9243f5b AB |
748 | #ifdef CONFIG_COMPAT |
749 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, | |
750 | compat_ulong_t __user *p) | |
751 | { | |
752 | int rv; | |
753 | unsigned long ntimeout; | |
754 | ||
755 | if ((rv = get_user(ntimeout, p)) || | |
756 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
757 | return rv; | |
758 | ||
759 | if (ntimeout > UINT_MAX/HZ) | |
760 | sbi->exp_timeout = 0; | |
761 | else | |
762 | sbi->exp_timeout = ntimeout * HZ; | |
763 | ||
764 | return 0; | |
765 | } | |
766 | #endif | |
767 | ||
1da177e4 LT |
768 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
769 | unsigned long __user *p) | |
770 | { | |
771 | int rv; | |
772 | unsigned long ntimeout; | |
773 | ||
d78e53c8 SB |
774 | if ((rv = get_user(ntimeout, p)) || |
775 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
776 | return rv; |
777 | ||
d78e53c8 | 778 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
779 | sbi->exp_timeout = 0; |
780 | else | |
781 | sbi->exp_timeout = ntimeout * HZ; | |
782 | ||
783 | return 0; | |
784 | } | |
785 | ||
786 | /* Return protocol version */ | |
787 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
788 | { | |
789 | return put_user(sbi->version, p); | |
790 | } | |
791 | ||
792 | /* Return protocol sub version */ | |
793 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
794 | { | |
795 | return put_user(sbi->sub_version, p); | |
796 | } | |
797 | ||
1da177e4 LT |
798 | /* |
799 | * Tells the daemon whether it can umount the autofs mount. | |
800 | */ | |
801 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
802 | { | |
803 | int status = 0; | |
804 | ||
e3474a8e | 805 | if (may_umount(mnt)) |
1da177e4 LT |
806 | status = 1; |
807 | ||
808 | DPRINTK("returning %d", status); | |
809 | ||
810 | status = put_user(status, p); | |
811 | ||
812 | return status; | |
813 | } | |
814 | ||
815 | /* Identify autofs4_dentries - this is so we can tell if there's | |
816 | an extra dentry refcount or not. We only hold a refcount on the | |
817 | dentry if its non-negative (ie, d_inode != NULL) | |
818 | */ | |
819 | int is_autofs4_dentry(struct dentry *dentry) | |
820 | { | |
821 | return dentry && dentry->d_inode && | |
b650c858 | 822 | dentry->d_op == &autofs4_dentry_operations && |
1da177e4 LT |
823 | dentry->d_fsdata != NULL; |
824 | } | |
825 | ||
826 | /* | |
827 | * ioctl()'s on the root directory is the chief method for the daemon to | |
828 | * generate kernel reactions | |
829 | */ | |
3663df70 FW |
830 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
831 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
832 | { |
833 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
834 | void __user *p = (void __user *)arg; | |
835 | ||
836 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 837 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 838 | |
d78e53c8 SB |
839 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
840 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
841 | return -ENOTTY; |
842 | ||
d78e53c8 | 843 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
844 | return -EPERM; |
845 | ||
846 | switch(cmd) { | |
847 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
848 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
849 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
850 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
851 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
852 | autofs4_catatonic_mode(sbi); | |
853 | return 0; | |
854 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
855 | return autofs4_get_protover(sbi, p); | |
856 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
857 | return autofs4_get_protosubver(sbi, p); | |
858 | case AUTOFS_IOC_SETTIMEOUT: | |
859 | return autofs4_get_set_timeout(sbi, p); | |
c9243f5b AB |
860 | #ifdef CONFIG_COMPAT |
861 | case AUTOFS_IOC_SETTIMEOUT32: | |
862 | return autofs4_compat_get_set_timeout(sbi, p); | |
863 | #endif | |
1da177e4 | 864 | |
1da177e4 | 865 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 866 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
867 | |
868 | /* return a single thing to expire */ | |
869 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 870 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
871 | /* same as above, but can send multiple expires through pipe */ |
872 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 873 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
874 | |
875 | default: | |
876 | return -ENOSYS; | |
877 | } | |
878 | } | |
3663df70 FW |
879 | |
880 | static long autofs4_root_ioctl(struct file *filp, | |
881 | unsigned int cmd, unsigned long arg) | |
882 | { | |
496ad9aa | 883 | struct inode *inode = file_inode(filp); |
de47de74 | 884 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
3663df70 | 885 | } |
c9243f5b AB |
886 | |
887 | #ifdef CONFIG_COMPAT | |
888 | static long autofs4_root_compat_ioctl(struct file *filp, | |
889 | unsigned int cmd, unsigned long arg) | |
890 | { | |
496ad9aa | 891 | struct inode *inode = file_inode(filp); |
c9243f5b AB |
892 | int ret; |
893 | ||
c9243f5b AB |
894 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
895 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); | |
896 | else | |
897 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, | |
898 | (unsigned long)compat_ptr(arg)); | |
c9243f5b AB |
899 | |
900 | return ret; | |
901 | } | |
902 | #endif |