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> | |
18 | #include <linux/param.h> | |
19 | #include <linux/time.h> | |
1da177e4 LT |
20 | #include "autofs_i.h" |
21 | ||
22 | static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); | |
23 | static int autofs4_dir_unlink(struct inode *,struct dentry *); | |
24 | static int autofs4_dir_rmdir(struct inode *,struct dentry *); | |
25 | static int autofs4_dir_mkdir(struct inode *,struct dentry *,int); | |
26 | static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long); | |
27 | static int autofs4_dir_open(struct inode *inode, struct file *file); | |
1da177e4 | 28 | static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); |
34ca959c | 29 | static void *autofs4_follow_link(struct dentry *, struct nameidata *); |
1da177e4 | 30 | |
6d5cb926 IK |
31 | #define TRIGGER_FLAGS (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) |
32 | #define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE) | |
33 | ||
4b6f5d20 | 34 | const struct file_operations autofs4_root_operations = { |
1da177e4 LT |
35 | .open = dcache_dir_open, |
36 | .release = dcache_dir_close, | |
37 | .read = generic_read_dir, | |
aa55ddf3 | 38 | .readdir = dcache_readdir, |
59af1584 | 39 | .llseek = dcache_dir_lseek, |
1da177e4 LT |
40 | .ioctl = autofs4_root_ioctl, |
41 | }; | |
42 | ||
4b6f5d20 | 43 | const struct file_operations autofs4_dir_operations = { |
1da177e4 | 44 | .open = autofs4_dir_open, |
ff9cd499 | 45 | .release = dcache_dir_close, |
1da177e4 | 46 | .read = generic_read_dir, |
ff9cd499 | 47 | .readdir = dcache_readdir, |
59af1584 | 48 | .llseek = dcache_dir_lseek, |
1da177e4 LT |
49 | }; |
50 | ||
754661f1 | 51 | const struct inode_operations autofs4_indirect_root_inode_operations = { |
1da177e4 LT |
52 | .lookup = autofs4_lookup, |
53 | .unlink = autofs4_dir_unlink, | |
54 | .symlink = autofs4_dir_symlink, | |
55 | .mkdir = autofs4_dir_mkdir, | |
56 | .rmdir = autofs4_dir_rmdir, | |
57 | }; | |
58 | ||
754661f1 | 59 | const struct inode_operations autofs4_direct_root_inode_operations = { |
34ca959c | 60 | .lookup = autofs4_lookup, |
871f9434 IK |
61 | .unlink = autofs4_dir_unlink, |
62 | .mkdir = autofs4_dir_mkdir, | |
63 | .rmdir = autofs4_dir_rmdir, | |
34ca959c IK |
64 | .follow_link = autofs4_follow_link, |
65 | }; | |
66 | ||
754661f1 | 67 | const struct inode_operations autofs4_dir_inode_operations = { |
1da177e4 LT |
68 | .lookup = autofs4_lookup, |
69 | .unlink = autofs4_dir_unlink, | |
70 | .symlink = autofs4_dir_symlink, | |
71 | .mkdir = autofs4_dir_mkdir, | |
72 | .rmdir = autofs4_dir_rmdir, | |
73 | }; | |
74 | ||
4f8427d1 IK |
75 | static void autofs4_add_active(struct dentry *dentry) |
76 | { | |
77 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
78 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
79 | if (ino) { | |
80 | spin_lock(&sbi->lookup_lock); | |
81 | if (!ino->active_count) { | |
82 | if (list_empty(&ino->active)) | |
83 | list_add(&ino->active, &sbi->active_list); | |
84 | } | |
85 | ino->active_count++; | |
86 | spin_unlock(&sbi->lookup_lock); | |
87 | } | |
88 | return; | |
89 | } | |
90 | ||
91 | static void autofs4_del_active(struct dentry *dentry) | |
92 | { | |
93 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
94 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
95 | if (ino) { | |
96 | spin_lock(&sbi->lookup_lock); | |
97 | ino->active_count--; | |
98 | if (!ino->active_count) { | |
99 | if (!list_empty(&ino->active)) | |
100 | list_del_init(&ino->active); | |
101 | } | |
102 | spin_unlock(&sbi->lookup_lock); | |
103 | } | |
104 | return; | |
105 | } | |
106 | ||
213614d5 IK |
107 | static void autofs4_add_rehash_entry(struct autofs_info *ino, |
108 | struct rehash_entry *entry) | |
109 | { | |
110 | entry->task = current; | |
111 | INIT_LIST_HEAD(&entry->list); | |
112 | list_add(&entry->list, &ino->rehash_list); | |
113 | return; | |
114 | } | |
115 | ||
116 | static void autofs4_remove_rehash_entry(struct autofs_info *ino) | |
117 | { | |
118 | struct list_head *head = &ino->rehash_list; | |
119 | struct rehash_entry *entry; | |
120 | list_for_each_entry(entry, head, list) { | |
121 | if (entry->task == current) { | |
122 | list_del(&entry->list); | |
123 | kfree(entry); | |
124 | break; | |
125 | } | |
126 | } | |
127 | return; | |
128 | } | |
129 | ||
130 | static void autofs4_remove_rehash_entrys(struct autofs_info *ino) | |
131 | { | |
132 | struct autofs_sb_info *sbi = ino->sbi; | |
133 | struct rehash_entry *entry, *next; | |
134 | struct list_head *head; | |
135 | ||
136 | spin_lock(&sbi->fs_lock); | |
137 | spin_lock(&sbi->lookup_lock); | |
138 | if (!(ino->flags & AUTOFS_INF_REHASH)) { | |
139 | spin_unlock(&sbi->lookup_lock); | |
140 | spin_unlock(&sbi->fs_lock); | |
141 | return; | |
142 | } | |
143 | ino->flags &= ~AUTOFS_INF_REHASH; | |
144 | head = &ino->rehash_list; | |
145 | list_for_each_entry_safe(entry, next, head, list) { | |
146 | list_del(&entry->list); | |
147 | kfree(entry); | |
148 | } | |
149 | spin_unlock(&sbi->lookup_lock); | |
150 | spin_unlock(&sbi->fs_lock); | |
151 | dput(ino->dentry); | |
152 | ||
153 | return; | |
154 | } | |
155 | ||
156 | static void autofs4_revalidate_drop(struct dentry *dentry, | |
157 | struct rehash_entry *entry) | |
158 | { | |
159 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
160 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
161 | /* | |
162 | * Add to the active list so we can pick this up in | |
163 | * ->lookup(). Also add an entry to a rehash list so | |
164 | * we know when there are no dentrys in flight so we | |
165 | * know when we can rehash the dentry. | |
166 | */ | |
167 | spin_lock(&sbi->lookup_lock); | |
168 | if (list_empty(&ino->active)) | |
169 | list_add(&ino->active, &sbi->active_list); | |
170 | autofs4_add_rehash_entry(ino, entry); | |
171 | spin_unlock(&sbi->lookup_lock); | |
172 | if (!(ino->flags & AUTOFS_INF_REHASH)) { | |
173 | ino->flags |= AUTOFS_INF_REHASH; | |
174 | dget(dentry); | |
175 | spin_lock(&dentry->d_lock); | |
176 | __d_drop(dentry); | |
177 | spin_unlock(&dentry->d_lock); | |
178 | } | |
179 | return; | |
180 | } | |
181 | ||
182 | static void autofs4_revalidate_rehash(struct dentry *dentry) | |
183 | { | |
184 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
185 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
186 | if (ino->flags & AUTOFS_INF_REHASH) { | |
187 | spin_lock(&sbi->lookup_lock); | |
188 | autofs4_remove_rehash_entry(ino); | |
189 | if (list_empty(&ino->rehash_list)) { | |
190 | spin_unlock(&sbi->lookup_lock); | |
191 | ino->flags &= ~AUTOFS_INF_REHASH; | |
192 | d_rehash(dentry); | |
193 | dput(ino->dentry); | |
194 | } else | |
195 | spin_unlock(&sbi->lookup_lock); | |
196 | } | |
197 | return; | |
198 | } | |
199 | ||
36b6413e IK |
200 | static unsigned int autofs4_need_mount(unsigned int flags) |
201 | { | |
202 | unsigned int res = 0; | |
203 | if (flags & (TRIGGER_FLAGS | TRIGGER_INTENTS)) | |
204 | res = 1; | |
205 | return res; | |
206 | } | |
207 | ||
1da177e4 LT |
208 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
209 | { | |
a4669ed8 | 210 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 211 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 212 | |
1da177e4 LT |
213 | DPRINTK("file=%p dentry=%p %.*s", |
214 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
215 | ||
216 | if (autofs4_oz_mode(sbi)) | |
217 | goto out; | |
218 | ||
ff9cd499 IK |
219 | /* |
220 | * An empty directory in an autofs file system is always a | |
221 | * mount point. The daemon must have failed to mount this | |
222 | * during lookup so it doesn't exist. This can happen, for | |
223 | * example, if user space returns an incorrect status for a | |
224 | * mount request. Otherwise we're doing a readdir on the | |
225 | * autofs file system so just let the libfs routines handle | |
226 | * it. | |
227 | */ | |
228 | spin_lock(&dcache_lock); | |
c42c7f7e | 229 | if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { |
1da177e4 | 230 | spin_unlock(&dcache_lock); |
ff9cd499 | 231 | return -ENOENT; |
1da177e4 | 232 | } |
ff9cd499 | 233 | spin_unlock(&dcache_lock); |
1da177e4 | 234 | |
1da177e4 | 235 | out: |
ff9cd499 | 236 | return dcache_dir_open(inode, file); |
1da177e4 LT |
237 | } |
238 | ||
213614d5 | 239 | static int try_to_fill_dentry(struct dentry *dentry) |
1da177e4 | 240 | { |
862b110f | 241 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
718c604a | 242 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
9d2de6ad | 243 | int status; |
1da177e4 | 244 | |
1da177e4 LT |
245 | DPRINTK("dentry=%p %.*s ino=%p", |
246 | dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); | |
247 | ||
718c604a IK |
248 | /* |
249 | * Wait for a pending mount, triggering one if there | |
250 | * isn't one already | |
251 | */ | |
213614d5 IK |
252 | DPRINTK("waiting for mount name=%.*s", |
253 | dentry->d_name.len, dentry->d_name.name); | |
1da177e4 | 254 | |
213614d5 | 255 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); |
718c604a | 256 | |
213614d5 | 257 | DPRINTK("mount done status=%d", status); |
1da177e4 | 258 | |
213614d5 IK |
259 | /* Update expiry counter */ |
260 | ino->last_used = jiffies; | |
1da177e4 | 261 | |
213614d5 | 262 | return status; |
34ca959c IK |
263 | } |
264 | ||
265 | /* For autofs direct mounts the follow link triggers the mount */ | |
266 | static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) | |
267 | { | |
268 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
a5370553 | 269 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
34ca959c IK |
270 | int oz_mode = autofs4_oz_mode(sbi); |
271 | unsigned int lookup_type; | |
272 | int status; | |
273 | ||
274 | DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d", | |
275 | dentry, dentry->d_name.len, dentry->d_name.name, oz_mode, | |
276 | nd->flags); | |
6e60a9ab IK |
277 | /* |
278 | * For an expire of a covered direct or offset mount we need | |
9393bd07 | 279 | * to break out of follow_down() at the autofs mount trigger |
6e60a9ab IK |
280 | * (d_mounted--), so we can see the expiring flag, and manage |
281 | * the blocking and following here until the expire is completed. | |
282 | */ | |
283 | if (oz_mode) { | |
284 | spin_lock(&sbi->fs_lock); | |
285 | if (ino->flags & AUTOFS_INF_EXPIRING) { | |
286 | spin_unlock(&sbi->fs_lock); | |
287 | /* Follow down to our covering mount. */ | |
9393bd07 | 288 | if (!follow_down(&nd->path)) |
6e60a9ab | 289 | goto done; |
ec6e8c7d | 290 | goto follow; |
6e60a9ab IK |
291 | } |
292 | spin_unlock(&sbi->fs_lock); | |
34ca959c | 293 | goto done; |
6e60a9ab | 294 | } |
34ca959c | 295 | |
6e60a9ab | 296 | /* If an expire request is pending everyone must wait. */ |
06a35985 | 297 | autofs4_expire_wait(dentry); |
871f9434 | 298 | |
6e60a9ab | 299 | /* We trigger a mount for almost all flags */ |
36b6413e | 300 | lookup_type = autofs4_need_mount(nd->flags); |
aa952eb2 IK |
301 | spin_lock(&sbi->fs_lock); |
302 | spin_lock(&dcache_lock); | |
303 | if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) { | |
304 | spin_unlock(&dcache_lock); | |
305 | spin_unlock(&sbi->fs_lock); | |
ec6e8c7d | 306 | goto follow; |
aa952eb2 | 307 | } |
6e60a9ab | 308 | |
871f9434 | 309 | /* |
6e60a9ab IK |
310 | * If the dentry contains directories then it is an autofs |
311 | * multi-mount with no root mount offset. So don't try to | |
312 | * mount it again. | |
871f9434 | 313 | */ |
aa952eb2 | 314 | if (ino->flags & AUTOFS_INF_PENDING || |
c42c7f7e | 315 | (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) { |
213614d5 | 316 | ino->flags |= AUTOFS_INF_PENDING; |
871f9434 | 317 | spin_unlock(&dcache_lock); |
aa952eb2 | 318 | spin_unlock(&sbi->fs_lock); |
871f9434 | 319 | |
213614d5 IK |
320 | status = try_to_fill_dentry(dentry); |
321 | ||
322 | spin_lock(&sbi->fs_lock); | |
323 | ino->flags &= ~AUTOFS_INF_PENDING; | |
324 | spin_unlock(&sbi->fs_lock); | |
325 | ||
871f9434 IK |
326 | if (status) |
327 | goto out_error; | |
328 | ||
6e60a9ab | 329 | goto follow; |
34ca959c | 330 | } |
871f9434 | 331 | spin_unlock(&dcache_lock); |
aa952eb2 | 332 | spin_unlock(&sbi->fs_lock); |
6e60a9ab IK |
333 | follow: |
334 | /* | |
335 | * If there is no root mount it must be an autofs | |
336 | * multi-mount with no root offset so we don't need | |
337 | * to follow it. | |
338 | */ | |
339 | if (d_mountpoint(dentry)) { | |
9393bd07 | 340 | if (!autofs4_follow_mount(&nd->path)) { |
6e60a9ab IK |
341 | status = -ENOENT; |
342 | goto out_error; | |
343 | } | |
344 | } | |
34ca959c IK |
345 | |
346 | done: | |
347 | return NULL; | |
348 | ||
349 | out_error: | |
1d957f9b | 350 | path_put(&nd->path); |
34ca959c | 351 | return ERR_PTR(status); |
1da177e4 LT |
352 | } |
353 | ||
354 | /* | |
355 | * Revalidate is called on every cache lookup. Some of those | |
356 | * cache lookups may actually happen while the dentry is not | |
357 | * yet completely filled in, and revalidate has to delay such | |
358 | * lookups.. | |
359 | */ | |
718c604a | 360 | static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 361 | { |
718c604a | 362 | struct inode *dir = dentry->d_parent->d_inode; |
1da177e4 | 363 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
213614d5 IK |
364 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
365 | struct rehash_entry *entry; | |
1da177e4 | 366 | int flags = nd ? nd->flags : 0; |
213614d5 IK |
367 | unsigned int mutex_aquired; |
368 | ||
369 | DPRINTK("name = %.*s oz_mode = %d", | |
370 | dentry->d_name.len, dentry->d_name.name, oz_mode); | |
371 | ||
372 | /* Daemon never causes a mount to trigger */ | |
373 | if (autofs4_oz_mode(sbi)) | |
374 | return 1; | |
375 | ||
376 | entry = kmalloc(sizeof(struct rehash_entry), GFP_KERNEL); | |
377 | if (!entry) | |
378 | return -ENOMEM; | |
379 | ||
380 | mutex_aquired = mutex_trylock(&dir->i_mutex); | |
1da177e4 | 381 | |
97e7449a | 382 | spin_lock(&sbi->fs_lock); |
213614d5 IK |
383 | spin_lock(&dcache_lock); |
384 | /* Pending dentry */ | |
1da177e4 | 385 | if (autofs4_ispending(dentry)) { |
213614d5 | 386 | int status; |
97e7449a | 387 | |
213614d5 IK |
388 | /* |
389 | * We can only unhash and send this to ->lookup() if | |
390 | * the directory mutex is held over d_revalidate() and | |
391 | * ->lookup(). This prevents the VFS from incorrectly | |
392 | * seeing the dentry as non-existent. | |
393 | */ | |
394 | ino->flags |= AUTOFS_INF_PENDING; | |
395 | if (!mutex_aquired) { | |
396 | autofs4_revalidate_drop(dentry, entry); | |
397 | spin_unlock(&dcache_lock); | |
398 | spin_unlock(&sbi->fs_lock); | |
399 | return 0; | |
400 | } | |
401 | spin_unlock(&dcache_lock); | |
402 | spin_unlock(&sbi->fs_lock); | |
403 | mutex_unlock(&dir->i_mutex); | |
404 | kfree(entry); | |
bcdc5e01 | 405 | |
06a35985 IK |
406 | /* |
407 | * If the directory has gone away due to an expire | |
408 | * we have been called as ->d_revalidate() and so | |
409 | * we need to return false and proceed to ->lookup(). | |
410 | */ | |
411 | if (autofs4_expire_wait(dentry) == -EAGAIN) | |
412 | return 0; | |
413 | ||
bcdc5e01 IK |
414 | /* |
415 | * A zero status is success otherwise we have a | |
416 | * negative error code. | |
417 | */ | |
213614d5 IK |
418 | status = try_to_fill_dentry(dentry); |
419 | ||
420 | spin_lock(&sbi->fs_lock); | |
421 | ino->flags &= ~AUTOFS_INF_PENDING; | |
422 | spin_unlock(&sbi->fs_lock); | |
423 | ||
bcdc5e01 | 424 | if (status == 0) |
f50b6f86 IK |
425 | return 1; |
426 | ||
bcdc5e01 | 427 | return status; |
1da177e4 | 428 | } |
1da177e4 LT |
429 | |
430 | /* Check for a non-mountpoint directory with no contents */ | |
1da177e4 | 431 | if (S_ISDIR(dentry->d_inode->i_mode) && |
c42c7f7e | 432 | !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { |
1da177e4 LT |
433 | DPRINTK("dentry=%p %.*s, emptydir", |
434 | dentry, dentry->d_name.len, dentry->d_name.name); | |
97e7449a | 435 | |
213614d5 IK |
436 | if (autofs4_need_mount(flags) || current->link_count) { |
437 | int status; | |
bcdc5e01 | 438 | |
213614d5 IK |
439 | /* |
440 | * We can only unhash and send this to ->lookup() if | |
441 | * the directory mutex is held over d_revalidate() and | |
442 | * ->lookup(). This prevents the VFS from incorrectly | |
443 | * seeing the dentry as non-existent. | |
444 | */ | |
445 | ino->flags |= AUTOFS_INF_PENDING; | |
446 | if (!mutex_aquired) { | |
447 | autofs4_revalidate_drop(dentry, entry); | |
448 | spin_unlock(&dcache_lock); | |
449 | spin_unlock(&sbi->fs_lock); | |
450 | return 0; | |
451 | } | |
452 | spin_unlock(&dcache_lock); | |
453 | spin_unlock(&sbi->fs_lock); | |
454 | mutex_unlock(&dir->i_mutex); | |
455 | kfree(entry); | |
bcdc5e01 | 456 | |
213614d5 IK |
457 | /* |
458 | * A zero status is success otherwise we have a | |
459 | * negative error code. | |
460 | */ | |
461 | status = try_to_fill_dentry(dentry); | |
462 | ||
463 | spin_lock(&sbi->fs_lock); | |
464 | ino->flags &= ~AUTOFS_INF_PENDING; | |
465 | spin_unlock(&sbi->fs_lock); | |
466 | ||
467 | if (status == 0) | |
468 | return 1; | |
469 | ||
470 | return status; | |
471 | } | |
1da177e4 LT |
472 | } |
473 | spin_unlock(&dcache_lock); | |
213614d5 IK |
474 | spin_unlock(&sbi->fs_lock); |
475 | ||
476 | if (mutex_aquired) | |
477 | mutex_unlock(&dir->i_mutex); | |
478 | ||
479 | kfree(entry); | |
1da177e4 | 480 | |
1da177e4 LT |
481 | return 1; |
482 | } | |
483 | ||
213614d5 IK |
484 | static void autofs4_free_rehash_entrys(struct autofs_info *inf) |
485 | { | |
486 | struct list_head *head = &inf->rehash_list; | |
487 | struct rehash_entry *entry, *next; | |
488 | list_for_each_entry_safe(entry, next, head, list) { | |
489 | list_del(&entry->list); | |
490 | kfree(entry); | |
491 | } | |
492 | } | |
493 | ||
34ca959c | 494 | void autofs4_dentry_release(struct dentry *de) |
1da177e4 LT |
495 | { |
496 | struct autofs_info *inf; | |
497 | ||
498 | DPRINTK("releasing %p", de); | |
499 | ||
500 | inf = autofs4_dentry_ino(de); | |
501 | de->d_fsdata = NULL; | |
502 | ||
503 | if (inf) { | |
f50b6f86 IK |
504 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); |
505 | ||
f50b6f86 | 506 | if (sbi) { |
5f6f4f28 | 507 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
508 | if (!list_empty(&inf->active)) |
509 | list_del(&inf->active); | |
5f6f4f28 IK |
510 | if (!list_empty(&inf->expiring)) |
511 | list_del(&inf->expiring); | |
213614d5 IK |
512 | if (!list_empty(&inf->rehash_list)) |
513 | autofs4_free_rehash_entrys(inf); | |
5f6f4f28 | 514 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
515 | } |
516 | ||
c3724b12 JM |
517 | inf->dentry = NULL; |
518 | inf->inode = NULL; | |
519 | ||
1da177e4 LT |
520 | autofs4_free_ino(inf); |
521 | } | |
522 | } | |
523 | ||
524 | /* For dentries of directories in the root dir */ | |
08f11513 | 525 | static const struct dentry_operations autofs4_root_dentry_operations = { |
1da177e4 LT |
526 | .d_revalidate = autofs4_revalidate, |
527 | .d_release = autofs4_dentry_release, | |
528 | }; | |
529 | ||
530 | /* For other dentries */ | |
08f11513 | 531 | static const struct dentry_operations autofs4_dentry_operations = { |
1da177e4 LT |
532 | .d_revalidate = autofs4_revalidate, |
533 | .d_release = autofs4_dentry_release, | |
534 | }; | |
535 | ||
6510c9d8 | 536 | static struct dentry *autofs4_lookup_active(struct dentry *dentry) |
25767378 | 537 | { |
6510c9d8 IK |
538 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
539 | struct dentry *parent = dentry->d_parent; | |
540 | struct qstr *name = &dentry->d_name; | |
25767378 IK |
541 | unsigned int len = name->len; |
542 | unsigned int hash = name->hash; | |
543 | const unsigned char *str = name->name; | |
544 | struct list_head *p, *head; | |
545 | ||
213614d5 | 546 | restart: |
25767378 IK |
547 | spin_lock(&dcache_lock); |
548 | spin_lock(&sbi->lookup_lock); | |
549 | head = &sbi->active_list; | |
550 | list_for_each(p, head) { | |
551 | struct autofs_info *ino; | |
e4d5ade7 | 552 | struct dentry *active; |
25767378 IK |
553 | struct qstr *qstr; |
554 | ||
555 | ino = list_entry(p, struct autofs_info, active); | |
e4d5ade7 | 556 | active = ino->dentry; |
25767378 | 557 | |
e4d5ade7 | 558 | spin_lock(&active->d_lock); |
25767378 IK |
559 | |
560 | /* Already gone? */ | |
e4d5ade7 | 561 | if (atomic_read(&active->d_count) == 0) |
25767378 IK |
562 | goto next; |
563 | ||
213614d5 IK |
564 | if (active->d_inode && IS_DEADDIR(active->d_inode)) { |
565 | if (!list_empty(&ino->rehash_list)) { | |
566 | dget(active); | |
567 | spin_unlock(&active->d_lock); | |
568 | spin_unlock(&sbi->lookup_lock); | |
569 | spin_unlock(&dcache_lock); | |
570 | autofs4_remove_rehash_entrys(ino); | |
571 | dput(active); | |
572 | goto restart; | |
573 | } | |
574 | goto next; | |
575 | } | |
576 | ||
e4d5ade7 | 577 | qstr = &active->d_name; |
25767378 | 578 | |
e4d5ade7 | 579 | if (active->d_name.hash != hash) |
25767378 | 580 | goto next; |
e4d5ade7 | 581 | if (active->d_parent != parent) |
25767378 IK |
582 | goto next; |
583 | ||
584 | if (qstr->len != len) | |
585 | goto next; | |
586 | if (memcmp(qstr->name, str, len)) | |
587 | goto next; | |
588 | ||
213614d5 IK |
589 | dget(active); |
590 | spin_unlock(&active->d_lock); | |
591 | spin_unlock(&sbi->lookup_lock); | |
592 | spin_unlock(&dcache_lock); | |
593 | return active; | |
25767378 | 594 | next: |
e4d5ade7 | 595 | spin_unlock(&active->d_lock); |
25767378 IK |
596 | } |
597 | spin_unlock(&sbi->lookup_lock); | |
598 | spin_unlock(&dcache_lock); | |
599 | ||
600 | return NULL; | |
601 | } | |
602 | ||
6510c9d8 | 603 | static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) |
f50b6f86 | 604 | { |
6510c9d8 IK |
605 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
606 | struct dentry *parent = dentry->d_parent; | |
607 | struct qstr *name = &dentry->d_name; | |
f50b6f86 IK |
608 | unsigned int len = name->len; |
609 | unsigned int hash = name->hash; | |
610 | const unsigned char *str = name->name; | |
611 | struct list_head *p, *head; | |
612 | ||
613 | spin_lock(&dcache_lock); | |
5f6f4f28 IK |
614 | spin_lock(&sbi->lookup_lock); |
615 | head = &sbi->expiring_list; | |
f50b6f86 IK |
616 | list_for_each(p, head) { |
617 | struct autofs_info *ino; | |
cb4b492a | 618 | struct dentry *expiring; |
f50b6f86 IK |
619 | struct qstr *qstr; |
620 | ||
5f6f4f28 | 621 | ino = list_entry(p, struct autofs_info, expiring); |
cb4b492a | 622 | expiring = ino->dentry; |
f50b6f86 | 623 | |
cb4b492a | 624 | spin_lock(&expiring->d_lock); |
f50b6f86 IK |
625 | |
626 | /* Bad luck, we've already been dentry_iput */ | |
cb4b492a | 627 | if (!expiring->d_inode) |
f50b6f86 IK |
628 | goto next; |
629 | ||
cb4b492a | 630 | qstr = &expiring->d_name; |
f50b6f86 | 631 | |
cb4b492a | 632 | if (expiring->d_name.hash != hash) |
f50b6f86 | 633 | goto next; |
cb4b492a | 634 | if (expiring->d_parent != parent) |
f50b6f86 IK |
635 | goto next; |
636 | ||
637 | if (qstr->len != len) | |
638 | goto next; | |
639 | if (memcmp(qstr->name, str, len)) | |
640 | goto next; | |
641 | ||
213614d5 IK |
642 | dget(expiring); |
643 | spin_unlock(&expiring->d_lock); | |
644 | spin_unlock(&sbi->lookup_lock); | |
645 | spin_unlock(&dcache_lock); | |
646 | return expiring; | |
f50b6f86 | 647 | next: |
cb4b492a | 648 | spin_unlock(&expiring->d_lock); |
f50b6f86 | 649 | } |
5f6f4f28 | 650 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
651 | spin_unlock(&dcache_lock); |
652 | ||
653 | return NULL; | |
654 | } | |
655 | ||
213614d5 IK |
656 | static struct autofs_info *init_new_dentry(struct autofs_sb_info *sbi, |
657 | struct dentry *dentry, int oz_mode) | |
658 | { | |
659 | struct autofs_info *ino; | |
660 | ||
661 | /* | |
662 | * Mark the dentry incomplete but don't hash it. We do this | |
663 | * to serialize our inode creation operations (symlink and | |
664 | * mkdir) which prevents deadlock during the callback to | |
665 | * the daemon. Subsequent user space lookups for the same | |
666 | * dentry are placed on the wait queue while the daemon | |
667 | * itself is allowed passage unresticted so the create | |
668 | * operation itself can then hash the dentry. Finally, | |
669 | * we check for the hashed dentry and return the newly | |
670 | * hashed dentry. | |
671 | */ | |
672 | dentry->d_op = &autofs4_root_dentry_operations; | |
673 | ||
674 | /* | |
675 | * And we need to ensure that the same dentry is used for | |
676 | * all following lookup calls until it is hashed so that | |
677 | * the dentry flags are persistent throughout the request. | |
678 | */ | |
679 | ino = autofs4_init_ino(NULL, sbi, 0555); | |
680 | if (!ino) | |
681 | return ERR_PTR(-ENOMEM); | |
682 | ||
683 | dentry->d_fsdata = ino; | |
684 | ino->dentry = dentry; | |
685 | ||
686 | /* | |
687 | * Only set the mount pending flag for new dentrys not created | |
688 | * by the daemon. | |
689 | */ | |
690 | if (!oz_mode) | |
691 | ino->flags |= AUTOFS_INF_PENDING; | |
692 | ||
693 | d_instantiate(dentry, NULL); | |
694 | ||
695 | return ino; | |
696 | } | |
697 | ||
1da177e4 LT |
698 | /* Lookups in the root directory */ |
699 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
700 | { | |
701 | struct autofs_sb_info *sbi; | |
25767378 | 702 | struct autofs_info *ino; |
90387c9c | 703 | struct dentry *expiring, *active; |
1da177e4 | 704 | int oz_mode; |
213614d5 | 705 | int status = 0; |
1da177e4 LT |
706 | |
707 | DPRINTK("name = %.*s", | |
708 | dentry->d_name.len, dentry->d_name.name); | |
709 | ||
718c604a | 710 | /* File name too long to exist */ |
1da177e4 | 711 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 712 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
713 | |
714 | sbi = autofs4_sbi(dir->i_sb); | |
1da177e4 | 715 | oz_mode = autofs4_oz_mode(sbi); |
718c604a | 716 | |
1da177e4 | 717 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
a47afb0f | 718 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); |
1da177e4 | 719 | |
213614d5 | 720 | spin_lock(&sbi->fs_lock); |
6510c9d8 | 721 | active = autofs4_lookup_active(dentry); |
90387c9c IK |
722 | if (active) { |
723 | dentry = active; | |
aa952eb2 | 724 | ino = autofs4_dentry_ino(dentry); |
213614d5 IK |
725 | /* If this came from revalidate, rehash it */ |
726 | autofs4_revalidate_rehash(dentry); | |
727 | spin_unlock(&sbi->fs_lock); | |
aa952eb2 | 728 | } else { |
213614d5 IK |
729 | spin_unlock(&sbi->fs_lock); |
730 | ino = init_new_dentry(sbi, dentry, oz_mode); | |
731 | if (IS_ERR(ino)) | |
732 | return (struct dentry *) ino; | |
25767378 | 733 | } |
5f6f4f28 | 734 | |
213614d5 IK |
735 | autofs4_add_active(dentry); |
736 | ||
1da177e4 | 737 | if (!oz_mode) { |
6510c9d8 | 738 | expiring = autofs4_lookup_expiring(dentry); |
213614d5 | 739 | mutex_unlock(&dir->i_mutex); |
8f63aaa8 IK |
740 | if (expiring) { |
741 | /* | |
742 | * If we are racing with expire the request might not | |
743 | * be quite complete but the directory has been removed | |
744 | * so it must have been successful, so just wait for it. | |
745 | */ | |
8f63aaa8 | 746 | autofs4_expire_wait(expiring); |
8f63aaa8 IK |
747 | dput(expiring); |
748 | } | |
213614d5 IK |
749 | status = try_to_fill_dentry(dentry); |
750 | mutex_lock(&dir->i_mutex); | |
aa952eb2 | 751 | spin_lock(&sbi->fs_lock); |
213614d5 | 752 | ino->flags &= ~AUTOFS_INF_PENDING; |
aa952eb2 | 753 | spin_unlock(&sbi->fs_lock); |
1da177e4 LT |
754 | } |
755 | ||
213614d5 IK |
756 | autofs4_del_active(dentry); |
757 | ||
1da177e4 | 758 | /* |
213614d5 | 759 | * If we had a mount fail, check if we had to handle |
1da177e4 LT |
760 | * a signal. If so we can force a restart.. |
761 | */ | |
213614d5 | 762 | if (status) { |
1da177e4 LT |
763 | /* See if we were interrupted */ |
764 | if (signal_pending(current)) { | |
765 | sigset_t *sigset = ¤t->pending.signal; | |
766 | if (sigismember (sigset, SIGKILL) || | |
767 | sigismember (sigset, SIGQUIT) || | |
768 | sigismember (sigset, SIGINT)) { | |
90387c9c IK |
769 | if (active) |
770 | dput(active); | |
1da177e4 LT |
771 | return ERR_PTR(-ERESTARTNOINTR); |
772 | } | |
773 | } | |
774 | } | |
775 | ||
776 | /* | |
213614d5 IK |
777 | * User space can (and has done in the past) remove and re-create |
778 | * this directory during the callback. This can leave us with an | |
779 | * unhashed dentry, but a successful mount! So we need to | |
780 | * perform another cached lookup in case the dentry now exists. | |
1da177e4 | 781 | */ |
213614d5 IK |
782 | if (!oz_mode && !have_submounts(dentry)) { |
783 | struct dentry *new; | |
784 | new = d_lookup(dentry->d_parent, &dentry->d_name); | |
785 | if (new) { | |
786 | if (active) | |
787 | dput(active); | |
788 | return new; | |
789 | } else { | |
790 | if (!status) | |
791 | status = -ENOENT; | |
792 | } | |
793 | } | |
c9ffec48 | 794 | |
213614d5 IK |
795 | /* |
796 | * If we had a mount failure, return status to user space. | |
797 | * If the mount succeeded and we used a dentry from the active queue | |
798 | * return it. | |
799 | */ | |
800 | if (status) { | |
801 | dentry = ERR_PTR(status); | |
90387c9c IK |
802 | if (active) |
803 | dput(active); | |
c9ffec48 | 804 | return dentry; |
213614d5 IK |
805 | } else { |
806 | /* | |
807 | * Valid successful mount, return active dentry or NULL | |
808 | * for a new dentry. | |
809 | */ | |
810 | if (active) | |
811 | return active; | |
f50b6f86 IK |
812 | } |
813 | ||
1da177e4 LT |
814 | return NULL; |
815 | } | |
816 | ||
817 | static int autofs4_dir_symlink(struct inode *dir, | |
818 | struct dentry *dentry, | |
819 | const char *symname) | |
820 | { | |
821 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
822 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 823 | struct autofs_info *p_ino; |
1da177e4 LT |
824 | struct inode *inode; |
825 | char *cp; | |
826 | ||
827 | DPRINTK("%s <- %.*s", symname, | |
828 | dentry->d_name.len, dentry->d_name.name); | |
829 | ||
830 | if (!autofs4_oz_mode(sbi)) | |
831 | return -EACCES; | |
832 | ||
833 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
25767378 IK |
834 | if (!ino) |
835 | return -ENOMEM; | |
1da177e4 | 836 | |
ef581a74 | 837 | ino->size = strlen(symname); |
25767378 IK |
838 | cp = kmalloc(ino->size + 1, GFP_KERNEL); |
839 | if (!cp) { | |
840 | if (!dentry->d_fsdata) | |
841 | kfree(ino); | |
842 | return -ENOMEM; | |
1da177e4 LT |
843 | } |
844 | ||
845 | strcpy(cp, symname); | |
846 | ||
847 | inode = autofs4_get_inode(dir->i_sb, ino); | |
25767378 IK |
848 | if (!inode) { |
849 | kfree(cp); | |
850 | if (!dentry->d_fsdata) | |
851 | kfree(ino); | |
852 | return -ENOMEM; | |
853 | } | |
1864f7bd | 854 | d_add(dentry, inode); |
1da177e4 LT |
855 | |
856 | if (dir == dir->i_sb->s_root->d_inode) | |
857 | dentry->d_op = &autofs4_root_dentry_operations; | |
858 | else | |
859 | dentry->d_op = &autofs4_dentry_operations; | |
860 | ||
861 | dentry->d_fsdata = ino; | |
862 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
863 | atomic_inc(&ino->count); |
864 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
865 | if (p_ino && dentry->d_parent != dentry) | |
866 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
867 | ino->inode = inode; |
868 | ||
25767378 | 869 | ino->u.symlink = cp; |
1da177e4 LT |
870 | dir->i_mtime = CURRENT_TIME; |
871 | ||
872 | return 0; | |
873 | } | |
874 | ||
875 | /* | |
876 | * NOTE! | |
877 | * | |
878 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
879 | * that the file no longer exists. However, doing that means that the | |
880 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 881 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
882 | * We simply d_drop it and add it to a expiring list in the super block, |
883 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
884 | * |
885 | * If a process is blocked on the dentry waiting for the expire to finish, | |
886 | * it will invalidate the dentry and try to mount with a new one. | |
887 | * | |
888 | * Also see autofs4_dir_rmdir().. | |
889 | */ | |
890 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
891 | { | |
892 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
893 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 894 | struct autofs_info *p_ino; |
1da177e4 LT |
895 | |
896 | /* This allows root to remove symlinks */ | |
d78e53c8 | 897 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
898 | return -EACCES; |
899 | ||
1aff3c8b IK |
900 | if (atomic_dec_and_test(&ino->count)) { |
901 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
902 | if (p_ino && dentry->d_parent != dentry) | |
903 | atomic_dec(&p_ino->count); | |
904 | } | |
1da177e4 LT |
905 | dput(ino->dentry); |
906 | ||
907 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 908 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
909 | |
910 | dir->i_mtime = CURRENT_TIME; | |
911 | ||
f50b6f86 | 912 | spin_lock(&dcache_lock); |
f50b6f86 IK |
913 | spin_lock(&dentry->d_lock); |
914 | __d_drop(dentry); | |
915 | spin_unlock(&dentry->d_lock); | |
916 | spin_unlock(&dcache_lock); | |
1da177e4 LT |
917 | |
918 | return 0; | |
919 | } | |
920 | ||
921 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
922 | { | |
923 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
924 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 925 | struct autofs_info *p_ino; |
1da177e4 | 926 | |
f50b6f86 IK |
927 | DPRINTK("dentry %p, removing %.*s", |
928 | dentry, dentry->d_name.len, dentry->d_name.name); | |
929 | ||
1da177e4 LT |
930 | if (!autofs4_oz_mode(sbi)) |
931 | return -EACCES; | |
932 | ||
933 | spin_lock(&dcache_lock); | |
934 | if (!list_empty(&dentry->d_subdirs)) { | |
935 | spin_unlock(&dcache_lock); | |
936 | return -ENOTEMPTY; | |
937 | } | |
938 | spin_lock(&dentry->d_lock); | |
939 | __d_drop(dentry); | |
940 | spin_unlock(&dentry->d_lock); | |
941 | spin_unlock(&dcache_lock); | |
942 | ||
1aff3c8b IK |
943 | if (atomic_dec_and_test(&ino->count)) { |
944 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
945 | if (p_ino && dentry->d_parent != dentry) | |
946 | atomic_dec(&p_ino->count); | |
947 | } | |
1da177e4 | 948 | dput(ino->dentry); |
1da177e4 | 949 | dentry->d_inode->i_size = 0; |
ce71ec36 | 950 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
951 | |
952 | if (dir->i_nlink) | |
9a53c3a7 | 953 | drop_nlink(dir); |
1da177e4 LT |
954 | |
955 | return 0; | |
956 | } | |
957 | ||
958 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
959 | { | |
960 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
961 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 962 | struct autofs_info *p_ino; |
1da177e4 LT |
963 | struct inode *inode; |
964 | ||
d78e53c8 | 965 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
966 | return -EACCES; |
967 | ||
968 | DPRINTK("dentry %p, creating %.*s", | |
969 | dentry, dentry->d_name.len, dentry->d_name.name); | |
970 | ||
971 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
25767378 IK |
972 | if (!ino) |
973 | return -ENOMEM; | |
974 | ||
1da177e4 | 975 | inode = autofs4_get_inode(dir->i_sb, ino); |
25767378 IK |
976 | if (!inode) { |
977 | if (!dentry->d_fsdata) | |
978 | kfree(ino); | |
979 | return -ENOMEM; | |
980 | } | |
1864f7bd | 981 | d_add(dentry, inode); |
1da177e4 LT |
982 | |
983 | if (dir == dir->i_sb->s_root->d_inode) | |
984 | dentry->d_op = &autofs4_root_dentry_operations; | |
985 | else | |
986 | dentry->d_op = &autofs4_dentry_operations; | |
987 | ||
988 | dentry->d_fsdata = ino; | |
989 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
990 | atomic_inc(&ino->count); |
991 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
992 | if (p_ino && dentry->d_parent != dentry) | |
993 | atomic_inc(&p_ino->count); | |
1da177e4 | 994 | ino->inode = inode; |
d8c76e6f | 995 | inc_nlink(dir); |
1da177e4 LT |
996 | dir->i_mtime = CURRENT_TIME; |
997 | ||
998 | return 0; | |
999 | } | |
1000 | ||
1001 | /* Get/set timeout ioctl() operation */ | |
1002 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, | |
1003 | unsigned long __user *p) | |
1004 | { | |
1005 | int rv; | |
1006 | unsigned long ntimeout; | |
1007 | ||
d78e53c8 SB |
1008 | if ((rv = get_user(ntimeout, p)) || |
1009 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
1010 | return rv; |
1011 | ||
d78e53c8 | 1012 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
1013 | sbi->exp_timeout = 0; |
1014 | else | |
1015 | sbi->exp_timeout = ntimeout * HZ; | |
1016 | ||
1017 | return 0; | |
1018 | } | |
1019 | ||
1020 | /* Return protocol version */ | |
1021 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
1022 | { | |
1023 | return put_user(sbi->version, p); | |
1024 | } | |
1025 | ||
1026 | /* Return protocol sub version */ | |
1027 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
1028 | { | |
1029 | return put_user(sbi->sub_version, p); | |
1030 | } | |
1031 | ||
1da177e4 LT |
1032 | /* |
1033 | * Tells the daemon whether it can umount the autofs mount. | |
1034 | */ | |
1035 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
1036 | { | |
1037 | int status = 0; | |
1038 | ||
e3474a8e | 1039 | if (may_umount(mnt)) |
1da177e4 LT |
1040 | status = 1; |
1041 | ||
1042 | DPRINTK("returning %d", status); | |
1043 | ||
1044 | status = put_user(status, p); | |
1045 | ||
1046 | return status; | |
1047 | } | |
1048 | ||
1049 | /* Identify autofs4_dentries - this is so we can tell if there's | |
1050 | an extra dentry refcount or not. We only hold a refcount on the | |
1051 | dentry if its non-negative (ie, d_inode != NULL) | |
1052 | */ | |
1053 | int is_autofs4_dentry(struct dentry *dentry) | |
1054 | { | |
1055 | return dentry && dentry->d_inode && | |
1056 | (dentry->d_op == &autofs4_root_dentry_operations || | |
1057 | dentry->d_op == &autofs4_dentry_operations) && | |
1058 | dentry->d_fsdata != NULL; | |
1059 | } | |
1060 | ||
1061 | /* | |
1062 | * ioctl()'s on the root directory is the chief method for the daemon to | |
1063 | * generate kernel reactions | |
1064 | */ | |
1065 | static int autofs4_root_ioctl(struct inode *inode, struct file *filp, | |
1066 | unsigned int cmd, unsigned long arg) | |
1067 | { | |
1068 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
1069 | void __user *p = (void __user *)arg; | |
1070 | ||
1071 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 1072 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 1073 | |
d78e53c8 SB |
1074 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
1075 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
1076 | return -ENOTTY; |
1077 | ||
d78e53c8 | 1078 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
1079 | return -EPERM; |
1080 | ||
1081 | switch(cmd) { | |
1082 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
1083 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
1084 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
1085 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
1086 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
1087 | autofs4_catatonic_mode(sbi); | |
1088 | return 0; | |
1089 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
1090 | return autofs4_get_protover(sbi, p); | |
1091 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
1092 | return autofs4_get_protosubver(sbi, p); | |
1093 | case AUTOFS_IOC_SETTIMEOUT: | |
1094 | return autofs4_get_set_timeout(sbi, p); | |
1095 | ||
1da177e4 | 1096 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 1097 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
1098 | |
1099 | /* return a single thing to expire */ | |
1100 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 1101 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
1102 | /* same as above, but can send multiple expires through pipe */ |
1103 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 1104 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
1105 | |
1106 | default: | |
1107 | return -ENOSYS; | |
1108 | } | |
1109 | } |