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 | ||
b5c84bf6 NP |
26 | DEFINE_SPINLOCK(autofs4_lock); |
27 | ||
1da177e4 LT |
28 | static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); |
29 | static int autofs4_dir_unlink(struct inode *,struct dentry *); | |
30 | static int autofs4_dir_rmdir(struct inode *,struct dentry *); | |
31 | static int autofs4_dir_mkdir(struct inode *,struct dentry *,int); | |
3663df70 | 32 | static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long); |
5a44a73b | 33 | #ifdef CONFIG_COMPAT |
c9243f5b | 34 | static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long); |
5a44a73b | 35 | #endif |
1da177e4 | 36 | static int autofs4_dir_open(struct inode *inode, struct file *file); |
1da177e4 | 37 | static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); |
71e469db IK |
38 | static struct vfsmount *autofs4_d_automount(struct path *); |
39 | static int autofs4_d_manage(struct dentry *, bool); | |
1da177e4 | 40 | |
4b6f5d20 | 41 | const struct file_operations autofs4_root_operations = { |
1da177e4 LT |
42 | .open = dcache_dir_open, |
43 | .release = dcache_dir_close, | |
44 | .read = generic_read_dir, | |
aa55ddf3 | 45 | .readdir = dcache_readdir, |
59af1584 | 46 | .llseek = dcache_dir_lseek, |
3663df70 | 47 | .unlocked_ioctl = autofs4_root_ioctl, |
c9243f5b AB |
48 | #ifdef CONFIG_COMPAT |
49 | .compat_ioctl = autofs4_root_compat_ioctl, | |
50 | #endif | |
1da177e4 LT |
51 | }; |
52 | ||
4b6f5d20 | 53 | const struct file_operations autofs4_dir_operations = { |
1da177e4 | 54 | .open = autofs4_dir_open, |
ff9cd499 | 55 | .release = dcache_dir_close, |
1da177e4 | 56 | .read = generic_read_dir, |
ff9cd499 | 57 | .readdir = dcache_readdir, |
59af1584 | 58 | .llseek = dcache_dir_lseek, |
1da177e4 LT |
59 | }; |
60 | ||
754661f1 | 61 | const struct inode_operations autofs4_dir_inode_operations = { |
1da177e4 LT |
62 | .lookup = autofs4_lookup, |
63 | .unlink = autofs4_dir_unlink, | |
64 | .symlink = autofs4_dir_symlink, | |
65 | .mkdir = autofs4_dir_mkdir, | |
66 | .rmdir = autofs4_dir_rmdir, | |
67 | }; | |
68 | ||
71e469db IK |
69 | /* For dentries that don't initiate mounting */ |
70 | const struct dentry_operations autofs4_dentry_operations = { | |
71 | .d_release = autofs4_dentry_release, | |
72 | }; | |
73 | ||
74 | /* For dentries that do initiate mounting */ | |
75 | const struct dentry_operations autofs4_mount_dentry_operations = { | |
76 | .d_automount = autofs4_d_automount, | |
77 | .d_manage = autofs4_d_manage, | |
78 | .d_release = autofs4_dentry_release, | |
79 | }; | |
80 | ||
4f8427d1 IK |
81 | static void autofs4_add_active(struct dentry *dentry) |
82 | { | |
83 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
84 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
85 | if (ino) { | |
86 | spin_lock(&sbi->lookup_lock); | |
87 | if (!ino->active_count) { | |
88 | if (list_empty(&ino->active)) | |
89 | list_add(&ino->active, &sbi->active_list); | |
90 | } | |
91 | ino->active_count++; | |
92 | spin_unlock(&sbi->lookup_lock); | |
93 | } | |
94 | return; | |
95 | } | |
96 | ||
97 | static void autofs4_del_active(struct dentry *dentry) | |
98 | { | |
99 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
100 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
101 | if (ino) { | |
102 | spin_lock(&sbi->lookup_lock); | |
103 | ino->active_count--; | |
104 | if (!ino->active_count) { | |
105 | if (!list_empty(&ino->active)) | |
106 | list_del_init(&ino->active); | |
107 | } | |
108 | spin_unlock(&sbi->lookup_lock); | |
109 | } | |
110 | return; | |
111 | } | |
112 | ||
1da177e4 LT |
113 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
114 | { | |
a4669ed8 | 115 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 116 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 117 | |
1da177e4 LT |
118 | DPRINTK("file=%p dentry=%p %.*s", |
119 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
120 | ||
121 | if (autofs4_oz_mode(sbi)) | |
122 | goto out; | |
123 | ||
ff9cd499 IK |
124 | /* |
125 | * An empty directory in an autofs file system is always a | |
126 | * mount point. The daemon must have failed to mount this | |
127 | * during lookup so it doesn't exist. This can happen, for | |
128 | * example, if user space returns an incorrect status for a | |
129 | * mount request. Otherwise we're doing a readdir on the | |
130 | * autofs file system so just let the libfs routines handle | |
131 | * it. | |
132 | */ | |
b5c84bf6 | 133 | spin_lock(&autofs4_lock); |
2fd6b7f5 | 134 | spin_lock(&dentry->d_lock); |
c42c7f7e | 135 | if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { |
2fd6b7f5 | 136 | spin_unlock(&dentry->d_lock); |
b5c84bf6 | 137 | spin_unlock(&autofs4_lock); |
ff9cd499 | 138 | return -ENOENT; |
1da177e4 | 139 | } |
2fd6b7f5 | 140 | spin_unlock(&dentry->d_lock); |
b5c84bf6 | 141 | spin_unlock(&autofs4_lock); |
1da177e4 | 142 | |
1da177e4 | 143 | out: |
ff9cd499 | 144 | return dcache_dir_open(inode, file); |
1da177e4 LT |
145 | } |
146 | ||
34ca959c | 147 | void autofs4_dentry_release(struct dentry *de) |
1da177e4 LT |
148 | { |
149 | struct autofs_info *inf; | |
150 | ||
151 | DPRINTK("releasing %p", de); | |
152 | ||
153 | inf = autofs4_dentry_ino(de); | |
154 | de->d_fsdata = NULL; | |
155 | ||
156 | if (inf) { | |
f50b6f86 IK |
157 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); |
158 | ||
f50b6f86 | 159 | if (sbi) { |
5f6f4f28 | 160 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
161 | if (!list_empty(&inf->active)) |
162 | list_del(&inf->active); | |
5f6f4f28 IK |
163 | if (!list_empty(&inf->expiring)) |
164 | list_del(&inf->expiring); | |
165 | spin_unlock(&sbi->lookup_lock); | |
f50b6f86 IK |
166 | } |
167 | ||
c3724b12 JM |
168 | inf->dentry = NULL; |
169 | inf->inode = NULL; | |
170 | ||
1da177e4 LT |
171 | autofs4_free_ino(inf); |
172 | } | |
173 | } | |
174 | ||
6510c9d8 | 175 | static struct dentry *autofs4_lookup_active(struct dentry *dentry) |
25767378 | 176 | { |
6510c9d8 IK |
177 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
178 | struct dentry *parent = dentry->d_parent; | |
179 | struct qstr *name = &dentry->d_name; | |
25767378 IK |
180 | unsigned int len = name->len; |
181 | unsigned int hash = name->hash; | |
182 | const unsigned char *str = name->name; | |
183 | struct list_head *p, *head; | |
184 | ||
b5c84bf6 | 185 | spin_lock(&autofs4_lock); |
25767378 IK |
186 | spin_lock(&sbi->lookup_lock); |
187 | head = &sbi->active_list; | |
188 | list_for_each(p, head) { | |
189 | struct autofs_info *ino; | |
e4d5ade7 | 190 | struct dentry *active; |
25767378 IK |
191 | struct qstr *qstr; |
192 | ||
193 | ino = list_entry(p, struct autofs_info, active); | |
e4d5ade7 | 194 | active = ino->dentry; |
25767378 | 195 | |
e4d5ade7 | 196 | spin_lock(&active->d_lock); |
25767378 IK |
197 | |
198 | /* Already gone? */ | |
b7ab39f6 | 199 | if (active->d_count == 0) |
25767378 IK |
200 | goto next; |
201 | ||
e4d5ade7 | 202 | qstr = &active->d_name; |
25767378 | 203 | |
e4d5ade7 | 204 | if (active->d_name.hash != hash) |
25767378 | 205 | goto next; |
e4d5ade7 | 206 | if (active->d_parent != parent) |
25767378 IK |
207 | goto next; |
208 | ||
209 | if (qstr->len != len) | |
210 | goto next; | |
211 | if (memcmp(qstr->name, str, len)) | |
212 | goto next; | |
213 | ||
4b1ae27a | 214 | if (d_unhashed(active)) { |
b7ab39f6 | 215 | dget_dlock(active); |
4b1ae27a AV |
216 | spin_unlock(&active->d_lock); |
217 | spin_unlock(&sbi->lookup_lock); | |
b5c84bf6 | 218 | spin_unlock(&autofs4_lock); |
4b1ae27a AV |
219 | return active; |
220 | } | |
25767378 | 221 | next: |
e4d5ade7 | 222 | spin_unlock(&active->d_lock); |
25767378 IK |
223 | } |
224 | spin_unlock(&sbi->lookup_lock); | |
b5c84bf6 | 225 | spin_unlock(&autofs4_lock); |
25767378 IK |
226 | |
227 | return NULL; | |
228 | } | |
229 | ||
6510c9d8 | 230 | static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) |
f50b6f86 | 231 | { |
6510c9d8 IK |
232 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
233 | struct dentry *parent = dentry->d_parent; | |
234 | struct qstr *name = &dentry->d_name; | |
f50b6f86 IK |
235 | unsigned int len = name->len; |
236 | unsigned int hash = name->hash; | |
237 | const unsigned char *str = name->name; | |
238 | struct list_head *p, *head; | |
239 | ||
b5c84bf6 | 240 | spin_lock(&autofs4_lock); |
5f6f4f28 IK |
241 | spin_lock(&sbi->lookup_lock); |
242 | head = &sbi->expiring_list; | |
f50b6f86 IK |
243 | list_for_each(p, head) { |
244 | struct autofs_info *ino; | |
cb4b492a | 245 | struct dentry *expiring; |
f50b6f86 IK |
246 | struct qstr *qstr; |
247 | ||
5f6f4f28 | 248 | ino = list_entry(p, struct autofs_info, expiring); |
cb4b492a | 249 | expiring = ino->dentry; |
f50b6f86 | 250 | |
cb4b492a | 251 | spin_lock(&expiring->d_lock); |
f50b6f86 IK |
252 | |
253 | /* Bad luck, we've already been dentry_iput */ | |
cb4b492a | 254 | if (!expiring->d_inode) |
f50b6f86 IK |
255 | goto next; |
256 | ||
cb4b492a | 257 | qstr = &expiring->d_name; |
f50b6f86 | 258 | |
cb4b492a | 259 | if (expiring->d_name.hash != hash) |
f50b6f86 | 260 | goto next; |
cb4b492a | 261 | if (expiring->d_parent != parent) |
f50b6f86 IK |
262 | goto next; |
263 | ||
264 | if (qstr->len != len) | |
265 | goto next; | |
266 | if (memcmp(qstr->name, str, len)) | |
267 | goto next; | |
268 | ||
4b1ae27a | 269 | if (d_unhashed(expiring)) { |
b7ab39f6 | 270 | dget_dlock(expiring); |
4b1ae27a AV |
271 | spin_unlock(&expiring->d_lock); |
272 | spin_unlock(&sbi->lookup_lock); | |
b5c84bf6 | 273 | spin_unlock(&autofs4_lock); |
4b1ae27a AV |
274 | return expiring; |
275 | } | |
f50b6f86 | 276 | next: |
cb4b492a | 277 | spin_unlock(&expiring->d_lock); |
f50b6f86 | 278 | } |
5f6f4f28 | 279 | spin_unlock(&sbi->lookup_lock); |
b5c84bf6 | 280 | spin_unlock(&autofs4_lock); |
f50b6f86 IK |
281 | |
282 | return NULL; | |
283 | } | |
284 | ||
10584211 IK |
285 | static int autofs4_mount_wait(struct dentry *dentry) |
286 | { | |
287 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
288 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
289 | int status; | |
290 | ||
291 | if (ino->flags & AUTOFS_INF_PENDING) { | |
292 | DPRINTK("waiting for mount name=%.*s", | |
293 | dentry->d_name.len, dentry->d_name.name); | |
294 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
295 | DPRINTK("mount wait done status=%d", status); | |
296 | ino->last_used = jiffies; | |
297 | return status; | |
298 | } | |
299 | return 0; | |
300 | } | |
301 | ||
302 | static int do_expire_wait(struct dentry *dentry) | |
303 | { | |
304 | struct dentry *expiring; | |
305 | ||
306 | expiring = autofs4_lookup_expiring(dentry); | |
307 | if (!expiring) | |
308 | return autofs4_expire_wait(dentry); | |
309 | else { | |
310 | /* | |
311 | * If we are racing with expire the request might not | |
312 | * be quite complete, but the directory has been removed | |
313 | * so it must have been successful, just wait for it. | |
314 | */ | |
315 | autofs4_expire_wait(expiring); | |
316 | autofs4_del_expiring(expiring); | |
317 | dput(expiring); | |
318 | } | |
319 | return 0; | |
320 | } | |
321 | ||
322 | static struct dentry *autofs4_mountpoint_changed(struct path *path) | |
323 | { | |
324 | struct dentry *dentry = path->dentry; | |
325 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
326 | ||
327 | /* | |
328 | * If this is an indirect mount the dentry could have gone away | |
329 | * as a result of an expire and a new one created. | |
330 | */ | |
331 | if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { | |
332 | struct dentry *parent = dentry->d_parent; | |
333 | struct dentry *new = d_lookup(parent, &dentry->d_name); | |
334 | if (!new) | |
335 | return NULL; | |
336 | dput(path->dentry); | |
337 | path->dentry = new; | |
338 | } | |
339 | return path->dentry; | |
340 | } | |
341 | ||
71e469db | 342 | static struct vfsmount *autofs4_d_automount(struct path *path) |
10584211 IK |
343 | { |
344 | struct dentry *dentry = path->dentry; | |
345 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
346 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
347 | int status; | |
348 | ||
349 | DPRINTK("dentry=%p %.*s", | |
350 | dentry, dentry->d_name.len, dentry->d_name.name); | |
351 | ||
b5b80177 IK |
352 | /* |
353 | * Someone may have manually umounted this or it was a submount | |
354 | * that has gone away. | |
355 | */ | |
356 | spin_lock(&dentry->d_lock); | |
357 | if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { | |
358 | if (!(dentry->d_flags & DCACHE_MANAGE_TRANSIT) && | |
359 | (dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) | |
360 | __managed_dentry_set_transit(path->dentry); | |
361 | } | |
362 | spin_unlock(&dentry->d_lock); | |
363 | ||
10584211 IK |
364 | /* The daemon never triggers a mount. */ |
365 | if (autofs4_oz_mode(sbi)) | |
366 | return NULL; | |
367 | ||
368 | /* | |
369 | * If an expire request is pending everyone must wait. | |
370 | * If the expire fails we're still mounted so continue | |
371 | * the follow and return. A return of -EAGAIN (which only | |
372 | * happens with indirect mounts) means the expire completed | |
373 | * and the directory was removed, so just go ahead and try | |
374 | * the mount. | |
375 | */ | |
376 | status = do_expire_wait(dentry); | |
377 | if (status && status != -EAGAIN) | |
378 | return NULL; | |
379 | ||
380 | /* Callback to the daemon to perform the mount or wait */ | |
381 | spin_lock(&sbi->fs_lock); | |
382 | if (ino->flags & AUTOFS_INF_PENDING) { | |
383 | spin_unlock(&sbi->fs_lock); | |
384 | status = autofs4_mount_wait(dentry); | |
385 | if (status) | |
386 | return ERR_PTR(status); | |
387 | spin_lock(&sbi->fs_lock); | |
388 | goto done; | |
389 | } | |
390 | ||
391 | /* | |
392 | * If the dentry is a symlink it's equivalent to a directory | |
b5b80177 | 393 | * having d_mountpoint() true, so there's no need to call back |
10584211 IK |
394 | * to the daemon. |
395 | */ | |
396 | if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) | |
397 | goto done; | |
b5b80177 IK |
398 | if (!d_mountpoint(dentry)) { |
399 | /* | |
400 | * It's possible that user space hasn't removed directories | |
401 | * after umounting a rootless multi-mount, although it | |
402 | * should. For v5 have_submounts() is sufficient to handle | |
403 | * this because the leaves of the directory tree under the | |
404 | * mount never trigger mounts themselves (they have an autofs | |
405 | * trigger mount mounted on them). But v4 pseudo direct mounts | |
406 | * do need the leaves to to trigger mounts. In this case we | |
407 | * have no choice but to use the list_empty() check and | |
408 | * require user space behave. | |
409 | */ | |
410 | if (sbi->version > 4) { | |
411 | if (have_submounts(dentry)) | |
412 | goto done; | |
413 | } else { | |
414 | spin_lock(&dentry->d_lock); | |
415 | if (!list_empty(&dentry->d_subdirs)) { | |
416 | spin_unlock(&dentry->d_lock); | |
417 | goto done; | |
418 | } | |
419 | spin_unlock(&dentry->d_lock); | |
420 | } | |
10584211 | 421 | ino->flags |= AUTOFS_INF_PENDING; |
10584211 IK |
422 | spin_unlock(&sbi->fs_lock); |
423 | status = autofs4_mount_wait(dentry); | |
424 | if (status) | |
425 | return ERR_PTR(status); | |
426 | spin_lock(&sbi->fs_lock); | |
427 | ino->flags &= ~AUTOFS_INF_PENDING; | |
10584211 | 428 | } |
10584211 | 429 | done: |
b5b80177 IK |
430 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { |
431 | /* | |
432 | * Any needed mounting has been completed and the path updated | |
433 | * so turn this into a normal dentry so we don't continually | |
434 | * call ->d_automount() and ->d_manage(). | |
435 | */ | |
436 | spin_lock(&dentry->d_lock); | |
437 | __managed_dentry_clear_transit(dentry); | |
438 | /* | |
439 | * Only clear DMANAGED_AUTOMOUNT for rootless multi-mounts and | |
440 | * symlinks as in all other cases the dentry will be covered by | |
441 | * an actual mount so ->d_automount() won't be called during | |
442 | * the follow. | |
443 | */ | |
444 | if ((!d_mountpoint(dentry) && | |
445 | !list_empty(&dentry->d_subdirs)) || | |
446 | (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))) | |
447 | __managed_dentry_clear_automount(dentry); | |
448 | spin_unlock(&dentry->d_lock); | |
449 | } | |
10584211 IK |
450 | spin_unlock(&sbi->fs_lock); |
451 | ||
452 | /* Mount succeeded, check if we ended up with a new dentry */ | |
453 | dentry = autofs4_mountpoint_changed(path); | |
454 | if (!dentry) | |
455 | return ERR_PTR(-ENOENT); | |
456 | ||
457 | return NULL; | |
458 | } | |
459 | ||
b5b80177 IK |
460 | int autofs4_d_manage(struct dentry *dentry, bool mounting_here) |
461 | { | |
462 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
463 | ||
464 | DPRINTK("dentry=%p %.*s", | |
465 | dentry, dentry->d_name.len, dentry->d_name.name); | |
466 | ||
467 | /* The daemon never waits. */ | |
468 | if (autofs4_oz_mode(sbi) || mounting_here) { | |
469 | if (!d_mountpoint(dentry)) | |
470 | return -EISDIR; | |
471 | return 0; | |
472 | } | |
473 | ||
474 | /* Wait for pending expires */ | |
475 | do_expire_wait(dentry); | |
476 | ||
477 | /* | |
478 | * This dentry may be under construction so wait on mount | |
479 | * completion. | |
480 | */ | |
481 | return autofs4_mount_wait(dentry); | |
482 | } | |
483 | ||
1da177e4 LT |
484 | /* Lookups in the root directory */ |
485 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
486 | { | |
487 | struct autofs_sb_info *sbi; | |
25767378 | 488 | struct autofs_info *ino; |
10584211 | 489 | struct dentry *active; |
1da177e4 | 490 | |
10584211 | 491 | DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name); |
1da177e4 | 492 | |
718c604a | 493 | /* File name too long to exist */ |
1da177e4 | 494 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 495 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
496 | |
497 | sbi = autofs4_sbi(dir->i_sb); | |
718c604a | 498 | |
1da177e4 | 499 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
10584211 | 500 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); |
1da177e4 | 501 | |
6510c9d8 | 502 | active = autofs4_lookup_active(dentry); |
90387c9c | 503 | if (active) { |
10584211 | 504 | return active; |
aa952eb2 | 505 | } else { |
71e469db | 506 | d_set_d_op(dentry, &autofs4_dentry_operations); |
4b1ae27a AV |
507 | |
508 | /* | |
10584211 IK |
509 | * A dentry that is not within the root can never trigger a |
510 | * mount operation, unless the directory already exists, so we | |
511 | * can return fail immediately. The daemon however does need | |
512 | * to create directories within the file system. | |
4b1ae27a | 513 | */ |
10584211 IK |
514 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
515 | return ERR_PTR(-ENOENT); | |
516 | ||
517 | /* Mark entries in the root as mount triggers */ | |
518 | if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) { | |
71e469db | 519 | d_set_d_op(dentry, &autofs4_mount_dentry_operations); |
b5b80177 | 520 | __managed_dentry_set_managed(dentry); |
10584211 IK |
521 | } |
522 | ||
4b1ae27a AV |
523 | ino = autofs4_init_ino(NULL, sbi, 0555); |
524 | if (!ino) | |
525 | return ERR_PTR(-ENOMEM); | |
526 | ||
527 | dentry->d_fsdata = ino; | |
528 | ino->dentry = dentry; | |
5f6f4f28 | 529 | |
4b1ae27a AV |
530 | autofs4_add_active(dentry); |
531 | ||
532 | d_instantiate(dentry, NULL); | |
533 | } | |
1da177e4 LT |
534 | return NULL; |
535 | } | |
536 | ||
537 | static int autofs4_dir_symlink(struct inode *dir, | |
538 | struct dentry *dentry, | |
539 | const char *symname) | |
540 | { | |
541 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
542 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 543 | struct autofs_info *p_ino; |
1da177e4 LT |
544 | struct inode *inode; |
545 | char *cp; | |
546 | ||
547 | DPRINTK("%s <- %.*s", symname, | |
548 | dentry->d_name.len, dentry->d_name.name); | |
549 | ||
550 | if (!autofs4_oz_mode(sbi)) | |
551 | return -EACCES; | |
552 | ||
553 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
25767378 IK |
554 | if (!ino) |
555 | return -ENOMEM; | |
1da177e4 | 556 | |
4b1ae27a AV |
557 | autofs4_del_active(dentry); |
558 | ||
ef581a74 | 559 | ino->size = strlen(symname); |
25767378 IK |
560 | cp = kmalloc(ino->size + 1, GFP_KERNEL); |
561 | if (!cp) { | |
562 | if (!dentry->d_fsdata) | |
563 | kfree(ino); | |
564 | return -ENOMEM; | |
1da177e4 LT |
565 | } |
566 | ||
567 | strcpy(cp, symname); | |
568 | ||
569 | inode = autofs4_get_inode(dir->i_sb, ino); | |
25767378 IK |
570 | if (!inode) { |
571 | kfree(cp); | |
572 | if (!dentry->d_fsdata) | |
573 | kfree(ino); | |
574 | return -ENOMEM; | |
575 | } | |
1864f7bd | 576 | d_add(dentry, inode); |
1da177e4 | 577 | |
71e469db IK |
578 | d_set_d_op(dentry, &autofs4_dentry_operations); |
579 | ||
1da177e4 LT |
580 | dentry->d_fsdata = ino; |
581 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
582 | atomic_inc(&ino->count); |
583 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
584 | if (p_ino && dentry->d_parent != dentry) | |
585 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
586 | ino->inode = inode; |
587 | ||
25767378 | 588 | ino->u.symlink = cp; |
1da177e4 LT |
589 | dir->i_mtime = CURRENT_TIME; |
590 | ||
591 | return 0; | |
592 | } | |
593 | ||
594 | /* | |
595 | * NOTE! | |
596 | * | |
597 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
598 | * that the file no longer exists. However, doing that means that the | |
599 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 600 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
601 | * We simply d_drop it and add it to a expiring list in the super block, |
602 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
603 | * |
604 | * If a process is blocked on the dentry waiting for the expire to finish, | |
605 | * it will invalidate the dentry and try to mount with a new one. | |
606 | * | |
607 | * Also see autofs4_dir_rmdir().. | |
608 | */ | |
609 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
610 | { | |
611 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
612 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 613 | struct autofs_info *p_ino; |
1da177e4 LT |
614 | |
615 | /* This allows root to remove symlinks */ | |
d78e53c8 | 616 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
617 | return -EACCES; |
618 | ||
1aff3c8b IK |
619 | if (atomic_dec_and_test(&ino->count)) { |
620 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
621 | if (p_ino && dentry->d_parent != dentry) | |
622 | atomic_dec(&p_ino->count); | |
623 | } | |
1da177e4 LT |
624 | dput(ino->dentry); |
625 | ||
626 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 627 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
628 | |
629 | dir->i_mtime = CURRENT_TIME; | |
630 | ||
b5c84bf6 | 631 | spin_lock(&autofs4_lock); |
4b1ae27a | 632 | autofs4_add_expiring(dentry); |
f50b6f86 IK |
633 | spin_lock(&dentry->d_lock); |
634 | __d_drop(dentry); | |
635 | spin_unlock(&dentry->d_lock); | |
b5c84bf6 | 636 | spin_unlock(&autofs4_lock); |
1da177e4 LT |
637 | |
638 | return 0; | |
639 | } | |
640 | ||
641 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
642 | { | |
643 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
644 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 645 | struct autofs_info *p_ino; |
1da177e4 | 646 | |
f50b6f86 IK |
647 | DPRINTK("dentry %p, removing %.*s", |
648 | dentry, dentry->d_name.len, dentry->d_name.name); | |
649 | ||
1da177e4 LT |
650 | if (!autofs4_oz_mode(sbi)) |
651 | return -EACCES; | |
652 | ||
b5c84bf6 | 653 | spin_lock(&autofs4_lock); |
2fd6b7f5 NP |
654 | spin_lock(&sbi->lookup_lock); |
655 | spin_lock(&dentry->d_lock); | |
1da177e4 | 656 | if (!list_empty(&dentry->d_subdirs)) { |
2fd6b7f5 NP |
657 | spin_unlock(&dentry->d_lock); |
658 | spin_unlock(&sbi->lookup_lock); | |
b5c84bf6 | 659 | spin_unlock(&autofs4_lock); |
1da177e4 LT |
660 | return -ENOTEMPTY; |
661 | } | |
2fd6b7f5 NP |
662 | __autofs4_add_expiring(dentry); |
663 | spin_unlock(&sbi->lookup_lock); | |
1da177e4 LT |
664 | __d_drop(dentry); |
665 | spin_unlock(&dentry->d_lock); | |
b5c84bf6 | 666 | spin_unlock(&autofs4_lock); |
1da177e4 | 667 | |
1aff3c8b IK |
668 | if (atomic_dec_and_test(&ino->count)) { |
669 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
670 | if (p_ino && dentry->d_parent != dentry) | |
671 | atomic_dec(&p_ino->count); | |
672 | } | |
1da177e4 | 673 | dput(ino->dentry); |
1da177e4 | 674 | dentry->d_inode->i_size = 0; |
ce71ec36 | 675 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
676 | |
677 | if (dir->i_nlink) | |
9a53c3a7 | 678 | drop_nlink(dir); |
1da177e4 LT |
679 | |
680 | return 0; | |
681 | } | |
682 | ||
683 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
684 | { | |
685 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
686 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 687 | struct autofs_info *p_ino; |
1da177e4 LT |
688 | struct inode *inode; |
689 | ||
d78e53c8 | 690 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
691 | return -EACCES; |
692 | ||
693 | DPRINTK("dentry %p, creating %.*s", | |
694 | dentry, dentry->d_name.len, dentry->d_name.name); | |
695 | ||
696 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
25767378 IK |
697 | if (!ino) |
698 | return -ENOMEM; | |
699 | ||
4b1ae27a AV |
700 | autofs4_del_active(dentry); |
701 | ||
1da177e4 | 702 | inode = autofs4_get_inode(dir->i_sb, ino); |
25767378 IK |
703 | if (!inode) { |
704 | if (!dentry->d_fsdata) | |
705 | kfree(ino); | |
706 | return -ENOMEM; | |
707 | } | |
1864f7bd | 708 | d_add(dentry, inode); |
1da177e4 | 709 | |
1da177e4 LT |
710 | dentry->d_fsdata = ino; |
711 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
712 | atomic_inc(&ino->count); |
713 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
714 | if (p_ino && dentry->d_parent != dentry) | |
715 | atomic_inc(&p_ino->count); | |
1da177e4 | 716 | ino->inode = inode; |
d8c76e6f | 717 | inc_nlink(dir); |
1da177e4 LT |
718 | dir->i_mtime = CURRENT_TIME; |
719 | ||
720 | return 0; | |
721 | } | |
722 | ||
723 | /* Get/set timeout ioctl() operation */ | |
c9243f5b AB |
724 | #ifdef CONFIG_COMPAT |
725 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, | |
726 | compat_ulong_t __user *p) | |
727 | { | |
728 | int rv; | |
729 | unsigned long ntimeout; | |
730 | ||
731 | if ((rv = get_user(ntimeout, p)) || | |
732 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
733 | return rv; | |
734 | ||
735 | if (ntimeout > UINT_MAX/HZ) | |
736 | sbi->exp_timeout = 0; | |
737 | else | |
738 | sbi->exp_timeout = ntimeout * HZ; | |
739 | ||
740 | return 0; | |
741 | } | |
742 | #endif | |
743 | ||
1da177e4 LT |
744 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
745 | unsigned long __user *p) | |
746 | { | |
747 | int rv; | |
748 | unsigned long ntimeout; | |
749 | ||
d78e53c8 SB |
750 | if ((rv = get_user(ntimeout, p)) || |
751 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
752 | return rv; |
753 | ||
d78e53c8 | 754 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
755 | sbi->exp_timeout = 0; |
756 | else | |
757 | sbi->exp_timeout = ntimeout * HZ; | |
758 | ||
759 | return 0; | |
760 | } | |
761 | ||
762 | /* Return protocol version */ | |
763 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
764 | { | |
765 | return put_user(sbi->version, p); | |
766 | } | |
767 | ||
768 | /* Return protocol sub version */ | |
769 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
770 | { | |
771 | return put_user(sbi->sub_version, p); | |
772 | } | |
773 | ||
1da177e4 LT |
774 | /* |
775 | * Tells the daemon whether it can umount the autofs mount. | |
776 | */ | |
777 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
778 | { | |
779 | int status = 0; | |
780 | ||
e3474a8e | 781 | if (may_umount(mnt)) |
1da177e4 LT |
782 | status = 1; |
783 | ||
784 | DPRINTK("returning %d", status); | |
785 | ||
786 | status = put_user(status, p); | |
787 | ||
788 | return status; | |
789 | } | |
790 | ||
791 | /* Identify autofs4_dentries - this is so we can tell if there's | |
792 | an extra dentry refcount or not. We only hold a refcount on the | |
793 | dentry if its non-negative (ie, d_inode != NULL) | |
794 | */ | |
795 | int is_autofs4_dentry(struct dentry *dentry) | |
796 | { | |
797 | return dentry && dentry->d_inode && | |
71e469db | 798 | (dentry->d_op == &autofs4_mount_dentry_operations || |
1da177e4 LT |
799 | dentry->d_op == &autofs4_dentry_operations) && |
800 | dentry->d_fsdata != NULL; | |
801 | } | |
802 | ||
803 | /* | |
804 | * ioctl()'s on the root directory is the chief method for the daemon to | |
805 | * generate kernel reactions | |
806 | */ | |
3663df70 FW |
807 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
808 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
809 | { |
810 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
811 | void __user *p = (void __user *)arg; | |
812 | ||
813 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 814 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 815 | |
d78e53c8 SB |
816 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
817 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
818 | return -ENOTTY; |
819 | ||
d78e53c8 | 820 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
821 | return -EPERM; |
822 | ||
823 | switch(cmd) { | |
824 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
825 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
826 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
827 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
828 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
829 | autofs4_catatonic_mode(sbi); | |
830 | return 0; | |
831 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
832 | return autofs4_get_protover(sbi, p); | |
833 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
834 | return autofs4_get_protosubver(sbi, p); | |
835 | case AUTOFS_IOC_SETTIMEOUT: | |
836 | return autofs4_get_set_timeout(sbi, p); | |
c9243f5b AB |
837 | #ifdef CONFIG_COMPAT |
838 | case AUTOFS_IOC_SETTIMEOUT32: | |
839 | return autofs4_compat_get_set_timeout(sbi, p); | |
840 | #endif | |
1da177e4 | 841 | |
1da177e4 | 842 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 843 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
844 | |
845 | /* return a single thing to expire */ | |
846 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 847 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
848 | /* same as above, but can send multiple expires through pipe */ |
849 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 850 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
851 | |
852 | default: | |
853 | return -ENOSYS; | |
854 | } | |
855 | } | |
3663df70 FW |
856 | |
857 | static long autofs4_root_ioctl(struct file *filp, | |
858 | unsigned int cmd, unsigned long arg) | |
859 | { | |
3663df70 | 860 | struct inode *inode = filp->f_dentry->d_inode; |
de47de74 | 861 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
3663df70 | 862 | } |
c9243f5b AB |
863 | |
864 | #ifdef CONFIG_COMPAT | |
865 | static long autofs4_root_compat_ioctl(struct file *filp, | |
866 | unsigned int cmd, unsigned long arg) | |
867 | { | |
868 | struct inode *inode = filp->f_path.dentry->d_inode; | |
869 | int ret; | |
870 | ||
c9243f5b AB |
871 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
872 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); | |
873 | else | |
874 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, | |
875 | (unsigned long)compat_ptr(arg)); | |
c9243f5b AB |
876 | |
877 | return ret; | |
878 | } | |
879 | #endif |