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, | |
aa55ddf3 | 44 | .readdir = 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, |
ff9cd499 | 56 | .readdir = 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 IK |
169 | spin_lock(&sbi->lookup_lock); |
170 | head = &sbi->active_list; | |
171 | list_for_each(p, head) { | |
172 | struct autofs_info *ino; | |
e4d5ade7 | 173 | struct dentry *active; |
25767378 IK |
174 | struct qstr *qstr; |
175 | ||
176 | ino = list_entry(p, struct autofs_info, active); | |
e4d5ade7 | 177 | active = ino->dentry; |
25767378 | 178 | |
e4d5ade7 | 179 | spin_lock(&active->d_lock); |
25767378 IK |
180 | |
181 | /* Already gone? */ | |
b7ab39f6 | 182 | if (active->d_count == 0) |
25767378 IK |
183 | goto next; |
184 | ||
e4d5ade7 | 185 | qstr = &active->d_name; |
25767378 | 186 | |
e4d5ade7 | 187 | if (active->d_name.hash != hash) |
25767378 | 188 | goto next; |
e4d5ade7 | 189 | if (active->d_parent != parent) |
25767378 IK |
190 | goto next; |
191 | ||
192 | if (qstr->len != len) | |
193 | goto next; | |
194 | if (memcmp(qstr->name, str, len)) | |
195 | goto next; | |
196 | ||
4b1ae27a | 197 | if (d_unhashed(active)) { |
b7ab39f6 | 198 | dget_dlock(active); |
4b1ae27a AV |
199 | spin_unlock(&active->d_lock); |
200 | spin_unlock(&sbi->lookup_lock); | |
4b1ae27a AV |
201 | return active; |
202 | } | |
25767378 | 203 | next: |
e4d5ade7 | 204 | spin_unlock(&active->d_lock); |
25767378 IK |
205 | } |
206 | spin_unlock(&sbi->lookup_lock); | |
25767378 IK |
207 | |
208 | return NULL; | |
209 | } | |
210 | ||
6510c9d8 | 211 | static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) |
f50b6f86 | 212 | { |
6510c9d8 IK |
213 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
214 | struct dentry *parent = dentry->d_parent; | |
215 | struct qstr *name = &dentry->d_name; | |
f50b6f86 IK |
216 | unsigned int len = name->len; |
217 | unsigned int hash = name->hash; | |
218 | const unsigned char *str = name->name; | |
219 | struct list_head *p, *head; | |
220 | ||
5f6f4f28 IK |
221 | spin_lock(&sbi->lookup_lock); |
222 | head = &sbi->expiring_list; | |
f50b6f86 IK |
223 | list_for_each(p, head) { |
224 | struct autofs_info *ino; | |
cb4b492a | 225 | struct dentry *expiring; |
f50b6f86 IK |
226 | struct qstr *qstr; |
227 | ||
5f6f4f28 | 228 | ino = list_entry(p, struct autofs_info, expiring); |
cb4b492a | 229 | expiring = ino->dentry; |
f50b6f86 | 230 | |
cb4b492a | 231 | spin_lock(&expiring->d_lock); |
f50b6f86 IK |
232 | |
233 | /* Bad luck, we've already been dentry_iput */ | |
cb4b492a | 234 | if (!expiring->d_inode) |
f50b6f86 IK |
235 | goto next; |
236 | ||
cb4b492a | 237 | qstr = &expiring->d_name; |
f50b6f86 | 238 | |
cb4b492a | 239 | if (expiring->d_name.hash != hash) |
f50b6f86 | 240 | goto next; |
cb4b492a | 241 | if (expiring->d_parent != parent) |
f50b6f86 IK |
242 | goto next; |
243 | ||
244 | if (qstr->len != len) | |
245 | goto next; | |
246 | if (memcmp(qstr->name, str, len)) | |
247 | goto next; | |
248 | ||
4b1ae27a | 249 | if (d_unhashed(expiring)) { |
b7ab39f6 | 250 | dget_dlock(expiring); |
4b1ae27a AV |
251 | spin_unlock(&expiring->d_lock); |
252 | spin_unlock(&sbi->lookup_lock); | |
4b1ae27a AV |
253 | return expiring; |
254 | } | |
f50b6f86 | 255 | next: |
cb4b492a | 256 | spin_unlock(&expiring->d_lock); |
f50b6f86 | 257 | } |
5f6f4f28 | 258 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
259 | |
260 | return NULL; | |
261 | } | |
262 | ||
10584211 IK |
263 | static int autofs4_mount_wait(struct dentry *dentry) |
264 | { | |
265 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
266 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
3c319985 | 267 | int status = 0; |
10584211 IK |
268 | |
269 | if (ino->flags & AUTOFS_INF_PENDING) { | |
270 | DPRINTK("waiting for mount name=%.*s", | |
271 | dentry->d_name.len, dentry->d_name.name); | |
272 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
273 | DPRINTK("mount wait done status=%d", status); | |
10584211 | 274 | } |
3c319985 IK |
275 | ino->last_used = jiffies; |
276 | return status; | |
10584211 IK |
277 | } |
278 | ||
279 | static int do_expire_wait(struct dentry *dentry) | |
280 | { | |
281 | struct dentry *expiring; | |
282 | ||
283 | expiring = autofs4_lookup_expiring(dentry); | |
284 | if (!expiring) | |
285 | return autofs4_expire_wait(dentry); | |
286 | else { | |
287 | /* | |
288 | * If we are racing with expire the request might not | |
289 | * be quite complete, but the directory has been removed | |
290 | * so it must have been successful, just wait for it. | |
291 | */ | |
292 | autofs4_expire_wait(expiring); | |
293 | autofs4_del_expiring(expiring); | |
294 | dput(expiring); | |
295 | } | |
296 | return 0; | |
297 | } | |
298 | ||
299 | static struct dentry *autofs4_mountpoint_changed(struct path *path) | |
300 | { | |
301 | struct dentry *dentry = path->dentry; | |
302 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
303 | ||
304 | /* | |
305 | * If this is an indirect mount the dentry could have gone away | |
306 | * as a result of an expire and a new one created. | |
307 | */ | |
308 | if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { | |
309 | struct dentry *parent = dentry->d_parent; | |
3c319985 | 310 | struct autofs_info *ino; |
10584211 IK |
311 | struct dentry *new = d_lookup(parent, &dentry->d_name); |
312 | if (!new) | |
313 | return NULL; | |
3c319985 IK |
314 | ino = autofs4_dentry_ino(new); |
315 | ino->last_used = jiffies; | |
10584211 IK |
316 | dput(path->dentry); |
317 | path->dentry = new; | |
318 | } | |
319 | return path->dentry; | |
320 | } | |
321 | ||
71e469db | 322 | static struct vfsmount *autofs4_d_automount(struct path *path) |
10584211 IK |
323 | { |
324 | struct dentry *dentry = path->dentry; | |
325 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
326 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
327 | int status; | |
328 | ||
329 | DPRINTK("dentry=%p %.*s", | |
330 | dentry, dentry->d_name.len, dentry->d_name.name); | |
331 | ||
332 | /* The daemon never triggers a mount. */ | |
333 | if (autofs4_oz_mode(sbi)) | |
334 | return NULL; | |
335 | ||
336 | /* | |
337 | * If an expire request is pending everyone must wait. | |
338 | * If the expire fails we're still mounted so continue | |
339 | * the follow and return. A return of -EAGAIN (which only | |
340 | * happens with indirect mounts) means the expire completed | |
341 | * and the directory was removed, so just go ahead and try | |
342 | * the mount. | |
343 | */ | |
344 | status = do_expire_wait(dentry); | |
345 | if (status && status != -EAGAIN) | |
346 | return NULL; | |
347 | ||
348 | /* Callback to the daemon to perform the mount or wait */ | |
349 | spin_lock(&sbi->fs_lock); | |
350 | if (ino->flags & AUTOFS_INF_PENDING) { | |
351 | spin_unlock(&sbi->fs_lock); | |
352 | status = autofs4_mount_wait(dentry); | |
353 | if (status) | |
354 | return ERR_PTR(status); | |
10584211 IK |
355 | goto done; |
356 | } | |
357 | ||
358 | /* | |
359 | * If the dentry is a symlink it's equivalent to a directory | |
b5b80177 | 360 | * having d_mountpoint() true, so there's no need to call back |
10584211 IK |
361 | * to the daemon. |
362 | */ | |
f55fb0c2 IK |
363 | if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) { |
364 | spin_unlock(&sbi->fs_lock); | |
10584211 | 365 | goto done; |
f55fb0c2 IK |
366 | } |
367 | ||
b5b80177 IK |
368 | if (!d_mountpoint(dentry)) { |
369 | /* | |
370 | * It's possible that user space hasn't removed directories | |
371 | * after umounting a rootless multi-mount, although it | |
372 | * should. For v5 have_submounts() is sufficient to handle | |
373 | * this because the leaves of the directory tree under the | |
374 | * mount never trigger mounts themselves (they have an autofs | |
375 | * trigger mount mounted on them). But v4 pseudo direct mounts | |
376 | * do need the leaves to to trigger mounts. In this case we | |
377 | * have no choice but to use the list_empty() check and | |
378 | * require user space behave. | |
379 | */ | |
380 | if (sbi->version > 4) { | |
f55fb0c2 IK |
381 | if (have_submounts(dentry)) { |
382 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 383 | goto done; |
f55fb0c2 | 384 | } |
b5b80177 | 385 | } else { |
0259cb02 | 386 | if (!simple_empty(dentry)) |
b5b80177 | 387 | goto done; |
b5b80177 | 388 | } |
10584211 | 389 | ino->flags |= AUTOFS_INF_PENDING; |
10584211 IK |
390 | spin_unlock(&sbi->fs_lock); |
391 | status = autofs4_mount_wait(dentry); | |
10584211 IK |
392 | spin_lock(&sbi->fs_lock); |
393 | ino->flags &= ~AUTOFS_INF_PENDING; | |
49999ab2 IK |
394 | if (status) { |
395 | spin_unlock(&sbi->fs_lock); | |
396 | return ERR_PTR(status); | |
397 | } | |
10584211 | 398 | } |
10584211 | 399 | spin_unlock(&sbi->fs_lock); |
f55fb0c2 | 400 | done: |
10584211 IK |
401 | /* Mount succeeded, check if we ended up with a new dentry */ |
402 | dentry = autofs4_mountpoint_changed(path); | |
403 | if (!dentry) | |
404 | return ERR_PTR(-ENOENT); | |
405 | ||
406 | return NULL; | |
407 | } | |
408 | ||
1aed3e42 | 409 | int autofs4_d_manage(struct dentry *dentry, bool rcu_walk) |
b5b80177 IK |
410 | { |
411 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f55fb0c2 IK |
412 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
413 | int status; | |
b5b80177 IK |
414 | |
415 | DPRINTK("dentry=%p %.*s", | |
416 | dentry, dentry->d_name.len, dentry->d_name.name); | |
417 | ||
418 | /* The daemon never waits. */ | |
1aed3e42 | 419 | if (autofs4_oz_mode(sbi)) { |
83fb96bf IK |
420 | if (rcu_walk) |
421 | return 0; | |
b5b80177 IK |
422 | if (!d_mountpoint(dentry)) |
423 | return -EISDIR; | |
424 | return 0; | |
425 | } | |
426 | ||
ab90911f DH |
427 | /* We need to sleep, so we need pathwalk to be in ref-mode */ |
428 | if (rcu_walk) | |
429 | return -ECHILD; | |
430 | ||
b5b80177 IK |
431 | /* Wait for pending expires */ |
432 | do_expire_wait(dentry); | |
433 | ||
434 | /* | |
435 | * This dentry may be under construction so wait on mount | |
436 | * completion. | |
437 | */ | |
f55fb0c2 IK |
438 | status = autofs4_mount_wait(dentry); |
439 | if (status) | |
440 | return status; | |
441 | ||
442 | spin_lock(&sbi->fs_lock); | |
443 | /* | |
444 | * If the dentry has been selected for expire while we slept | |
445 | * on the lock then it might go away. We'll deal with that in | |
446 | * ->d_automount() and wait on a new mount if the expire | |
447 | * succeeds or return here if it doesn't (since there's no | |
448 | * mount to follow with a rootless multi-mount). | |
449 | */ | |
450 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { | |
451 | /* | |
452 | * Any needed mounting has been completed and the path | |
453 | * updated so check if this is a rootless multi-mount so | |
454 | * we can avoid needless calls ->d_automount() and avoid | |
455 | * an incorrect ELOOP error return. | |
456 | */ | |
457 | if ((!d_mountpoint(dentry) && !simple_empty(dentry)) || | |
458 | (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))) | |
459 | status = -EISDIR; | |
460 | } | |
461 | spin_unlock(&sbi->fs_lock); | |
462 | ||
463 | return status; | |
b5b80177 IK |
464 | } |
465 | ||
1da177e4 | 466 | /* Lookups in the root directory */ |
00cd8dd3 | 467 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 LT |
468 | { |
469 | struct autofs_sb_info *sbi; | |
25767378 | 470 | struct autofs_info *ino; |
10584211 | 471 | struct dentry *active; |
1da177e4 | 472 | |
10584211 | 473 | DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name); |
1da177e4 | 474 | |
718c604a | 475 | /* File name too long to exist */ |
1da177e4 | 476 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 477 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
478 | |
479 | sbi = autofs4_sbi(dir->i_sb); | |
718c604a | 480 | |
1da177e4 | 481 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
c0bcc9d5 IK |
482 | current->pid, task_pgrp_nr(current), sbi->catatonic, |
483 | autofs4_oz_mode(sbi)); | |
1da177e4 | 484 | |
6510c9d8 | 485 | active = autofs4_lookup_active(dentry); |
90387c9c | 486 | if (active) { |
10584211 | 487 | return active; |
aa952eb2 | 488 | } else { |
4b1ae27a | 489 | /* |
10584211 IK |
490 | * A dentry that is not within the root can never trigger a |
491 | * mount operation, unless the directory already exists, so we | |
492 | * can return fail immediately. The daemon however does need | |
493 | * to create directories within the file system. | |
4b1ae27a | 494 | */ |
10584211 IK |
495 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
496 | return ERR_PTR(-ENOENT); | |
497 | ||
498 | /* Mark entries in the root as mount triggers */ | |
b650c858 | 499 | if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) |
b5b80177 | 500 | __managed_dentry_set_managed(dentry); |
10584211 | 501 | |
26e6c910 | 502 | ino = autofs4_new_ino(sbi); |
4b1ae27a AV |
503 | if (!ino) |
504 | return ERR_PTR(-ENOMEM); | |
505 | ||
506 | dentry->d_fsdata = ino; | |
507 | ino->dentry = dentry; | |
5f6f4f28 | 508 | |
4b1ae27a AV |
509 | autofs4_add_active(dentry); |
510 | ||
511 | d_instantiate(dentry, NULL); | |
512 | } | |
1da177e4 LT |
513 | return NULL; |
514 | } | |
515 | ||
516 | static int autofs4_dir_symlink(struct inode *dir, | |
517 | struct dentry *dentry, | |
518 | const char *symname) | |
519 | { | |
520 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
521 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 522 | struct autofs_info *p_ino; |
1da177e4 | 523 | struct inode *inode; |
0bf71d4d | 524 | size_t size = strlen(symname); |
1da177e4 LT |
525 | char *cp; |
526 | ||
527 | DPRINTK("%s <- %.*s", symname, | |
528 | dentry->d_name.len, dentry->d_name.name); | |
529 | ||
530 | if (!autofs4_oz_mode(sbi)) | |
531 | return -EACCES; | |
532 | ||
5a37db30 AV |
533 | BUG_ON(!ino); |
534 | ||
26e6c910 | 535 | autofs4_clean_ino(ino); |
1da177e4 | 536 | |
4b1ae27a AV |
537 | autofs4_del_active(dentry); |
538 | ||
0bf71d4d | 539 | cp = kmalloc(size + 1, GFP_KERNEL); |
5a37db30 | 540 | if (!cp) |
25767378 | 541 | return -ENOMEM; |
1da177e4 LT |
542 | |
543 | strcpy(cp, symname); | |
544 | ||
726a5e06 | 545 | inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555); |
25767378 IK |
546 | if (!inode) { |
547 | kfree(cp); | |
548 | if (!dentry->d_fsdata) | |
549 | kfree(ino); | |
550 | return -ENOMEM; | |
551 | } | |
292c5ee8 | 552 | inode->i_private = cp; |
0bf71d4d | 553 | inode->i_size = size; |
1864f7bd | 554 | d_add(dentry, inode); |
1da177e4 | 555 | |
5a37db30 | 556 | dget(dentry); |
1aff3c8b IK |
557 | atomic_inc(&ino->count); |
558 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
559 | if (p_ino && dentry->d_parent != dentry) | |
560 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
561 | |
562 | dir->i_mtime = CURRENT_TIME; | |
563 | ||
564 | return 0; | |
565 | } | |
566 | ||
567 | /* | |
568 | * NOTE! | |
569 | * | |
570 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
571 | * that the file no longer exists. However, doing that means that the | |
572 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 573 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
574 | * We simply d_drop it and add it to a expiring list in the super block, |
575 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
576 | * |
577 | * If a process is blocked on the dentry waiting for the expire to finish, | |
578 | * it will invalidate the dentry and try to mount with a new one. | |
579 | * | |
580 | * Also see autofs4_dir_rmdir().. | |
581 | */ | |
582 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
583 | { | |
584 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
585 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 586 | struct autofs_info *p_ino; |
1da177e4 LT |
587 | |
588 | /* This allows root to remove symlinks */ | |
d78e53c8 | 589 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
590 | return -EACCES; |
591 | ||
1aff3c8b IK |
592 | if (atomic_dec_and_test(&ino->count)) { |
593 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
594 | if (p_ino && dentry->d_parent != dentry) | |
595 | atomic_dec(&p_ino->count); | |
596 | } | |
1da177e4 LT |
597 | dput(ino->dentry); |
598 | ||
599 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 600 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
601 | |
602 | dir->i_mtime = CURRENT_TIME; | |
603 | ||
e7854723 IK |
604 | spin_lock(&sbi->lookup_lock); |
605 | __autofs4_add_expiring(dentry); | |
0259cb02 | 606 | d_drop(dentry); |
e7854723 | 607 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
608 | |
609 | return 0; | |
610 | } | |
611 | ||
dd89f90d IK |
612 | /* |
613 | * Version 4 of autofs provides a pseudo direct mount implementation | |
614 | * that relies on directories at the leaves of a directory tree under | |
615 | * an indirect mount to trigger mounts. To allow for this we need to | |
616 | * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves | |
617 | * of the directory tree. There is no need to clear the automount flag | |
618 | * following a mount or restore it after an expire because these mounts | |
25985edc | 619 | * are always covered. However, it is necessary to ensure that these |
dd89f90d IK |
620 | * flags are clear on non-empty directories to avoid unnecessary calls |
621 | * during path walks. | |
622 | */ | |
623 | static void autofs_set_leaf_automount_flags(struct dentry *dentry) | |
624 | { | |
625 | struct dentry *parent; | |
626 | ||
627 | /* root and dentrys in the root are already handled */ | |
628 | if (IS_ROOT(dentry->d_parent)) | |
629 | return; | |
630 | ||
631 | managed_dentry_set_managed(dentry); | |
632 | ||
633 | parent = dentry->d_parent; | |
634 | /* only consider parents below dentrys in the root */ | |
635 | if (IS_ROOT(parent->d_parent)) | |
636 | return; | |
637 | managed_dentry_clear_managed(parent); | |
638 | return; | |
639 | } | |
640 | ||
641 | static void autofs_clear_leaf_automount_flags(struct dentry *dentry) | |
642 | { | |
643 | struct list_head *d_child; | |
644 | struct dentry *parent; | |
645 | ||
646 | /* flags for dentrys in the root are handled elsewhere */ | |
647 | if (IS_ROOT(dentry->d_parent)) | |
648 | return; | |
649 | ||
650 | managed_dentry_clear_managed(dentry); | |
651 | ||
652 | parent = dentry->d_parent; | |
653 | /* only consider parents below dentrys in the root */ | |
654 | if (IS_ROOT(parent->d_parent)) | |
655 | return; | |
656 | d_child = &dentry->d_u.d_child; | |
657 | /* Set parent managed if it's becoming empty */ | |
658 | if (d_child->next == &parent->d_subdirs && | |
659 | d_child->prev == &parent->d_subdirs) | |
660 | managed_dentry_set_managed(parent); | |
661 | return; | |
662 | } | |
663 | ||
1da177e4 LT |
664 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
665 | { | |
666 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
667 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 668 | struct autofs_info *p_ino; |
1da177e4 | 669 | |
f50b6f86 IK |
670 | DPRINTK("dentry %p, removing %.*s", |
671 | dentry, dentry->d_name.len, dentry->d_name.name); | |
672 | ||
1da177e4 LT |
673 | if (!autofs4_oz_mode(sbi)) |
674 | return -EACCES; | |
675 | ||
2fd6b7f5 | 676 | spin_lock(&sbi->lookup_lock); |
0259cb02 | 677 | if (!simple_empty(dentry)) { |
2fd6b7f5 | 678 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
679 | return -ENOTEMPTY; |
680 | } | |
2fd6b7f5 | 681 | __autofs4_add_expiring(dentry); |
0259cb02 | 682 | d_drop(dentry); |
e7854723 | 683 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 684 | |
dd89f90d IK |
685 | if (sbi->version < 5) |
686 | autofs_clear_leaf_automount_flags(dentry); | |
687 | ||
1aff3c8b IK |
688 | if (atomic_dec_and_test(&ino->count)) { |
689 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
690 | if (p_ino && dentry->d_parent != dentry) | |
691 | atomic_dec(&p_ino->count); | |
692 | } | |
1da177e4 | 693 | dput(ino->dentry); |
1da177e4 | 694 | dentry->d_inode->i_size = 0; |
ce71ec36 | 695 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
696 | |
697 | if (dir->i_nlink) | |
9a53c3a7 | 698 | drop_nlink(dir); |
1da177e4 LT |
699 | |
700 | return 0; | |
701 | } | |
702 | ||
18bb1db3 | 703 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
704 | { |
705 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
706 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 707 | struct autofs_info *p_ino; |
1da177e4 LT |
708 | struct inode *inode; |
709 | ||
d78e53c8 | 710 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
711 | return -EACCES; |
712 | ||
713 | DPRINTK("dentry %p, creating %.*s", | |
714 | dentry, dentry->d_name.len, dentry->d_name.name); | |
715 | ||
5a37db30 AV |
716 | BUG_ON(!ino); |
717 | ||
26e6c910 | 718 | autofs4_clean_ino(ino); |
25767378 | 719 | |
4b1ae27a AV |
720 | autofs4_del_active(dentry); |
721 | ||
726a5e06 | 722 | inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555); |
5a37db30 | 723 | if (!inode) |
25767378 | 724 | return -ENOMEM; |
1864f7bd | 725 | d_add(dentry, inode); |
1da177e4 | 726 | |
dd89f90d IK |
727 | if (sbi->version < 5) |
728 | autofs_set_leaf_automount_flags(dentry); | |
729 | ||
5a37db30 | 730 | dget(dentry); |
1aff3c8b IK |
731 | atomic_inc(&ino->count); |
732 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
733 | if (p_ino && dentry->d_parent != dentry) | |
734 | atomic_inc(&p_ino->count); | |
d8c76e6f | 735 | inc_nlink(dir); |
1da177e4 LT |
736 | dir->i_mtime = CURRENT_TIME; |
737 | ||
738 | return 0; | |
739 | } | |
740 | ||
741 | /* Get/set timeout ioctl() operation */ | |
c9243f5b AB |
742 | #ifdef CONFIG_COMPAT |
743 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, | |
744 | compat_ulong_t __user *p) | |
745 | { | |
746 | int rv; | |
747 | unsigned long ntimeout; | |
748 | ||
749 | if ((rv = get_user(ntimeout, p)) || | |
750 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
751 | return rv; | |
752 | ||
753 | if (ntimeout > UINT_MAX/HZ) | |
754 | sbi->exp_timeout = 0; | |
755 | else | |
756 | sbi->exp_timeout = ntimeout * HZ; | |
757 | ||
758 | return 0; | |
759 | } | |
760 | #endif | |
761 | ||
1da177e4 LT |
762 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
763 | unsigned long __user *p) | |
764 | { | |
765 | int rv; | |
766 | unsigned long ntimeout; | |
767 | ||
d78e53c8 SB |
768 | if ((rv = get_user(ntimeout, p)) || |
769 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
770 | return rv; |
771 | ||
d78e53c8 | 772 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
773 | sbi->exp_timeout = 0; |
774 | else | |
775 | sbi->exp_timeout = ntimeout * HZ; | |
776 | ||
777 | return 0; | |
778 | } | |
779 | ||
780 | /* Return protocol version */ | |
781 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
782 | { | |
783 | return put_user(sbi->version, p); | |
784 | } | |
785 | ||
786 | /* Return protocol sub version */ | |
787 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
788 | { | |
789 | return put_user(sbi->sub_version, p); | |
790 | } | |
791 | ||
1da177e4 LT |
792 | /* |
793 | * Tells the daemon whether it can umount the autofs mount. | |
794 | */ | |
795 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
796 | { | |
797 | int status = 0; | |
798 | ||
e3474a8e | 799 | if (may_umount(mnt)) |
1da177e4 LT |
800 | status = 1; |
801 | ||
802 | DPRINTK("returning %d", status); | |
803 | ||
804 | status = put_user(status, p); | |
805 | ||
806 | return status; | |
807 | } | |
808 | ||
809 | /* Identify autofs4_dentries - this is so we can tell if there's | |
810 | an extra dentry refcount or not. We only hold a refcount on the | |
811 | dentry if its non-negative (ie, d_inode != NULL) | |
812 | */ | |
813 | int is_autofs4_dentry(struct dentry *dentry) | |
814 | { | |
815 | return dentry && dentry->d_inode && | |
b650c858 | 816 | dentry->d_op == &autofs4_dentry_operations && |
1da177e4 LT |
817 | dentry->d_fsdata != NULL; |
818 | } | |
819 | ||
820 | /* | |
821 | * ioctl()'s on the root directory is the chief method for the daemon to | |
822 | * generate kernel reactions | |
823 | */ | |
3663df70 FW |
824 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
825 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
826 | { |
827 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
828 | void __user *p = (void __user *)arg; | |
829 | ||
830 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 831 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 832 | |
d78e53c8 SB |
833 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
834 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
835 | return -ENOTTY; |
836 | ||
d78e53c8 | 837 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
838 | return -EPERM; |
839 | ||
840 | switch(cmd) { | |
841 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
842 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
843 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
844 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
845 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
846 | autofs4_catatonic_mode(sbi); | |
847 | return 0; | |
848 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
849 | return autofs4_get_protover(sbi, p); | |
850 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
851 | return autofs4_get_protosubver(sbi, p); | |
852 | case AUTOFS_IOC_SETTIMEOUT: | |
853 | return autofs4_get_set_timeout(sbi, p); | |
c9243f5b AB |
854 | #ifdef CONFIG_COMPAT |
855 | case AUTOFS_IOC_SETTIMEOUT32: | |
856 | return autofs4_compat_get_set_timeout(sbi, p); | |
857 | #endif | |
1da177e4 | 858 | |
1da177e4 | 859 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 860 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
861 | |
862 | /* return a single thing to expire */ | |
863 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 864 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
865 | /* same as above, but can send multiple expires through pipe */ |
866 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 867 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
868 | |
869 | default: | |
870 | return -ENOSYS; | |
871 | } | |
872 | } | |
3663df70 FW |
873 | |
874 | static long autofs4_root_ioctl(struct file *filp, | |
875 | unsigned int cmd, unsigned long arg) | |
876 | { | |
496ad9aa | 877 | struct inode *inode = file_inode(filp); |
de47de74 | 878 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
3663df70 | 879 | } |
c9243f5b AB |
880 | |
881 | #ifdef CONFIG_COMPAT | |
882 | static long autofs4_root_compat_ioctl(struct file *filp, | |
883 | unsigned int cmd, unsigned long arg) | |
884 | { | |
496ad9aa | 885 | struct inode *inode = file_inode(filp); |
c9243f5b AB |
886 | int ret; |
887 | ||
c9243f5b AB |
888 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
889 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); | |
890 | else | |
891 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, | |
892 | (unsigned long)compat_ptr(arg)); | |
c9243f5b AB |
893 | |
894 | return ret; | |
895 | } | |
896 | #endif |