Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* -*- c -*- --------------------------------------------------------------- * |
2 | * | |
3 | * linux/fs/autofs/root.c | |
4 | * | |
5 | * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved | |
6 | * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> | |
34ca959c | 7 | * Copyright 2001-2006 Ian Kent <raven@themaw.net> |
1da177e4 LT |
8 | * |
9 | * This file is part of the Linux kernel and is made available under | |
10 | * the terms of the GNU General Public License, version 2, or at your | |
11 | * option, any later version, incorporated herein by reference. | |
12 | * | |
13 | * ------------------------------------------------------------------------- */ | |
14 | ||
16f7e0fe | 15 | #include <linux/capability.h> |
1da177e4 LT |
16 | #include <linux/errno.h> |
17 | #include <linux/stat.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
1da177e4 LT |
19 | #include <linux/param.h> |
20 | #include <linux/time.h> | |
c9243f5b | 21 | #include <linux/compat.h> |
00e300e1 | 22 | #include <linux/mutex.h> |
c9243f5b | 23 | |
1da177e4 LT |
24 | #include "autofs_i.h" |
25 | ||
26 | static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); | |
27 | static int autofs4_dir_unlink(struct inode *,struct dentry *); | |
28 | static int autofs4_dir_rmdir(struct inode *,struct dentry *); | |
18bb1db3 | 29 | static int autofs4_dir_mkdir(struct inode *,struct dentry *,umode_t); |
3663df70 | 30 | static long autofs4_root_ioctl(struct file *,unsigned int,unsigned long); |
5a44a73b | 31 | #ifdef CONFIG_COMPAT |
c9243f5b | 32 | static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long); |
5a44a73b | 33 | #endif |
1da177e4 | 34 | static int autofs4_dir_open(struct inode *inode, struct file *file); |
00cd8dd3 | 35 | static struct dentry *autofs4_lookup(struct inode *,struct dentry *, unsigned int); |
71e469db | 36 | static struct vfsmount *autofs4_d_automount(struct path *); |
1aed3e42 | 37 | static int autofs4_d_manage(struct dentry *, bool); |
b89b12b4 | 38 | static void autofs4_dentry_release(struct dentry *); |
1da177e4 | 39 | |
4b6f5d20 | 40 | const struct file_operations autofs4_root_operations = { |
1da177e4 LT |
41 | .open = dcache_dir_open, |
42 | .release = dcache_dir_close, | |
43 | .read = generic_read_dir, | |
5f99f4e7 | 44 | .iterate = dcache_readdir, |
59af1584 | 45 | .llseek = dcache_dir_lseek, |
3663df70 | 46 | .unlocked_ioctl = autofs4_root_ioctl, |
c9243f5b AB |
47 | #ifdef CONFIG_COMPAT |
48 | .compat_ioctl = autofs4_root_compat_ioctl, | |
49 | #endif | |
1da177e4 LT |
50 | }; |
51 | ||
4b6f5d20 | 52 | const struct file_operations autofs4_dir_operations = { |
1da177e4 | 53 | .open = autofs4_dir_open, |
ff9cd499 | 54 | .release = dcache_dir_close, |
1da177e4 | 55 | .read = generic_read_dir, |
5f99f4e7 | 56 | .iterate = dcache_readdir, |
59af1584 | 57 | .llseek = dcache_dir_lseek, |
1da177e4 LT |
58 | }; |
59 | ||
754661f1 | 60 | const struct inode_operations autofs4_dir_inode_operations = { |
1da177e4 LT |
61 | .lookup = autofs4_lookup, |
62 | .unlink = autofs4_dir_unlink, | |
63 | .symlink = autofs4_dir_symlink, | |
64 | .mkdir = autofs4_dir_mkdir, | |
65 | .rmdir = autofs4_dir_rmdir, | |
66 | }; | |
67 | ||
71e469db | 68 | const struct dentry_operations autofs4_dentry_operations = { |
71e469db IK |
69 | .d_automount = autofs4_d_automount, |
70 | .d_manage = autofs4_d_manage, | |
71 | .d_release = autofs4_dentry_release, | |
72 | }; | |
73 | ||
4f8427d1 IK |
74 | static void autofs4_add_active(struct dentry *dentry) |
75 | { | |
76 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
77 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
78 | if (ino) { | |
79 | spin_lock(&sbi->lookup_lock); | |
80 | if (!ino->active_count) { | |
81 | if (list_empty(&ino->active)) | |
82 | list_add(&ino->active, &sbi->active_list); | |
83 | } | |
84 | ino->active_count++; | |
85 | spin_unlock(&sbi->lookup_lock); | |
86 | } | |
87 | return; | |
88 | } | |
89 | ||
90 | static void autofs4_del_active(struct dentry *dentry) | |
91 | { | |
92 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
93 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
94 | if (ino) { | |
95 | spin_lock(&sbi->lookup_lock); | |
96 | ino->active_count--; | |
97 | if (!ino->active_count) { | |
98 | if (!list_empty(&ino->active)) | |
99 | list_del_init(&ino->active); | |
100 | } | |
101 | spin_unlock(&sbi->lookup_lock); | |
102 | } | |
103 | return; | |
104 | } | |
105 | ||
1da177e4 LT |
106 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
107 | { | |
a4669ed8 | 108 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 109 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 110 | |
1da177e4 LT |
111 | DPRINTK("file=%p dentry=%p %.*s", |
112 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
113 | ||
114 | if (autofs4_oz_mode(sbi)) | |
115 | goto out; | |
116 | ||
ff9cd499 IK |
117 | /* |
118 | * An empty directory in an autofs file system is always a | |
119 | * mount point. The daemon must have failed to mount this | |
120 | * during lookup so it doesn't exist. This can happen, for | |
121 | * example, if user space returns an incorrect status for a | |
122 | * mount request. Otherwise we're doing a readdir on the | |
123 | * autofs file system so just let the libfs routines handle | |
124 | * it. | |
125 | */ | |
e7854723 | 126 | spin_lock(&sbi->lookup_lock); |
0259cb02 | 127 | if (!d_mountpoint(dentry) && simple_empty(dentry)) { |
e7854723 | 128 | spin_unlock(&sbi->lookup_lock); |
ff9cd499 | 129 | return -ENOENT; |
1da177e4 | 130 | } |
e7854723 | 131 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 132 | |
1da177e4 | 133 | out: |
ff9cd499 | 134 | return dcache_dir_open(inode, file); |
1da177e4 LT |
135 | } |
136 | ||
b89b12b4 | 137 | static void autofs4_dentry_release(struct dentry *de) |
1da177e4 | 138 | { |
b89b12b4 AV |
139 | struct autofs_info *ino = autofs4_dentry_ino(de); |
140 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); | |
1da177e4 LT |
141 | |
142 | DPRINTK("releasing %p", de); | |
143 | ||
b89b12b4 AV |
144 | if (!ino) |
145 | return; | |
146 | ||
147 | if (sbi) { | |
148 | spin_lock(&sbi->lookup_lock); | |
149 | if (!list_empty(&ino->active)) | |
150 | list_del(&ino->active); | |
151 | if (!list_empty(&ino->expiring)) | |
152 | list_del(&ino->expiring); | |
153 | spin_unlock(&sbi->lookup_lock); | |
1da177e4 | 154 | } |
b89b12b4 AV |
155 | |
156 | autofs4_free_ino(ino); | |
1da177e4 LT |
157 | } |
158 | ||
6510c9d8 | 159 | static struct dentry *autofs4_lookup_active(struct dentry *dentry) |
25767378 | 160 | { |
6510c9d8 IK |
161 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
162 | struct dentry *parent = dentry->d_parent; | |
163 | struct qstr *name = &dentry->d_name; | |
25767378 IK |
164 | unsigned int len = name->len; |
165 | unsigned int hash = name->hash; | |
166 | const unsigned char *str = name->name; | |
167 | struct list_head *p, *head; | |
168 | ||
25767378 | 169 | head = &sbi->active_list; |
668128e9 N |
170 | if (list_empty(head)) |
171 | return NULL; | |
172 | spin_lock(&sbi->lookup_lock); | |
25767378 IK |
173 | list_for_each(p, head) { |
174 | struct autofs_info *ino; | |
e4d5ade7 | 175 | struct dentry *active; |
25767378 IK |
176 | struct qstr *qstr; |
177 | ||
178 | ino = list_entry(p, struct autofs_info, active); | |
e4d5ade7 | 179 | active = ino->dentry; |
25767378 | 180 | |
e4d5ade7 | 181 | spin_lock(&active->d_lock); |
25767378 IK |
182 | |
183 | /* Already gone? */ | |
6b6751f7 | 184 | if ((int) d_count(active) <= 0) |
25767378 IK |
185 | goto next; |
186 | ||
e4d5ade7 | 187 | qstr = &active->d_name; |
25767378 | 188 | |
e4d5ade7 | 189 | if (active->d_name.hash != hash) |
25767378 | 190 | goto next; |
e4d5ade7 | 191 | if (active->d_parent != parent) |
25767378 IK |
192 | goto next; |
193 | ||
194 | if (qstr->len != len) | |
195 | goto next; | |
196 | if (memcmp(qstr->name, str, len)) | |
197 | goto next; | |
198 | ||
4b1ae27a | 199 | if (d_unhashed(active)) { |
b7ab39f6 | 200 | dget_dlock(active); |
4b1ae27a AV |
201 | spin_unlock(&active->d_lock); |
202 | spin_unlock(&sbi->lookup_lock); | |
4b1ae27a AV |
203 | return active; |
204 | } | |
25767378 | 205 | next: |
e4d5ade7 | 206 | spin_unlock(&active->d_lock); |
25767378 IK |
207 | } |
208 | spin_unlock(&sbi->lookup_lock); | |
25767378 IK |
209 | |
210 | return NULL; | |
211 | } | |
212 | ||
23bfc2a2 N |
213 | static struct dentry *autofs4_lookup_expiring(struct dentry *dentry, |
214 | bool rcu_walk) | |
f50b6f86 | 215 | { |
6510c9d8 IK |
216 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
217 | struct dentry *parent = dentry->d_parent; | |
218 | struct qstr *name = &dentry->d_name; | |
f50b6f86 IK |
219 | unsigned int len = name->len; |
220 | unsigned int hash = name->hash; | |
221 | const unsigned char *str = name->name; | |
222 | struct list_head *p, *head; | |
223 | ||
5f6f4f28 | 224 | head = &sbi->expiring_list; |
668128e9 N |
225 | if (list_empty(head)) |
226 | return NULL; | |
227 | spin_lock(&sbi->lookup_lock); | |
f50b6f86 IK |
228 | list_for_each(p, head) { |
229 | struct autofs_info *ino; | |
cb4b492a | 230 | struct dentry *expiring; |
f50b6f86 IK |
231 | struct qstr *qstr; |
232 | ||
23bfc2a2 N |
233 | if (rcu_walk) { |
234 | spin_unlock(&sbi->lookup_lock); | |
235 | return ERR_PTR(-ECHILD); | |
236 | } | |
237 | ||
5f6f4f28 | 238 | ino = list_entry(p, struct autofs_info, expiring); |
cb4b492a | 239 | expiring = ino->dentry; |
f50b6f86 | 240 | |
cb4b492a | 241 | spin_lock(&expiring->d_lock); |
f50b6f86 | 242 | |
6b6751f7 | 243 | /* We've already been dentry_iput or unlinked */ |
cb4b492a | 244 | if (!expiring->d_inode) |
f50b6f86 IK |
245 | goto next; |
246 | ||
cb4b492a | 247 | qstr = &expiring->d_name; |
f50b6f86 | 248 | |
cb4b492a | 249 | if (expiring->d_name.hash != hash) |
f50b6f86 | 250 | goto next; |
cb4b492a | 251 | if (expiring->d_parent != parent) |
f50b6f86 IK |
252 | goto next; |
253 | ||
254 | if (qstr->len != len) | |
255 | goto next; | |
256 | if (memcmp(qstr->name, str, len)) | |
257 | goto next; | |
258 | ||
4b1ae27a | 259 | if (d_unhashed(expiring)) { |
b7ab39f6 | 260 | dget_dlock(expiring); |
4b1ae27a AV |
261 | spin_unlock(&expiring->d_lock); |
262 | spin_unlock(&sbi->lookup_lock); | |
4b1ae27a AV |
263 | return expiring; |
264 | } | |
f50b6f86 | 265 | next: |
cb4b492a | 266 | spin_unlock(&expiring->d_lock); |
f50b6f86 | 267 | } |
5f6f4f28 | 268 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
269 | |
270 | return NULL; | |
271 | } | |
272 | ||
23bfc2a2 | 273 | static int autofs4_mount_wait(struct dentry *dentry, bool rcu_walk) |
10584211 IK |
274 | { |
275 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
276 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
3c319985 | 277 | int status = 0; |
10584211 IK |
278 | |
279 | if (ino->flags & AUTOFS_INF_PENDING) { | |
23bfc2a2 N |
280 | if (rcu_walk) |
281 | return -ECHILD; | |
10584211 IK |
282 | DPRINTK("waiting for mount name=%.*s", |
283 | dentry->d_name.len, dentry->d_name.name); | |
284 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
285 | DPRINTK("mount wait done status=%d", status); | |
10584211 | 286 | } |
3c319985 IK |
287 | ino->last_used = jiffies; |
288 | return status; | |
10584211 IK |
289 | } |
290 | ||
23bfc2a2 | 291 | static int do_expire_wait(struct dentry *dentry, bool rcu_walk) |
10584211 IK |
292 | { |
293 | struct dentry *expiring; | |
294 | ||
23bfc2a2 N |
295 | expiring = autofs4_lookup_expiring(dentry, rcu_walk); |
296 | if (IS_ERR(expiring)) | |
297 | return PTR_ERR(expiring); | |
10584211 | 298 | if (!expiring) |
23bfc2a2 | 299 | return autofs4_expire_wait(dentry, rcu_walk); |
10584211 IK |
300 | else { |
301 | /* | |
302 | * If we are racing with expire the request might not | |
303 | * be quite complete, but the directory has been removed | |
304 | * so it must have been successful, just wait for it. | |
305 | */ | |
23bfc2a2 | 306 | autofs4_expire_wait(expiring, 0); |
10584211 IK |
307 | autofs4_del_expiring(expiring); |
308 | dput(expiring); | |
309 | } | |
310 | return 0; | |
311 | } | |
312 | ||
313 | static struct dentry *autofs4_mountpoint_changed(struct path *path) | |
314 | { | |
315 | struct dentry *dentry = path->dentry; | |
316 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
317 | ||
318 | /* | |
319 | * If this is an indirect mount the dentry could have gone away | |
320 | * as a result of an expire and a new one created. | |
321 | */ | |
322 | if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { | |
323 | struct dentry *parent = dentry->d_parent; | |
3c319985 | 324 | struct autofs_info *ino; |
10584211 IK |
325 | struct dentry *new = d_lookup(parent, &dentry->d_name); |
326 | if (!new) | |
327 | return NULL; | |
3c319985 IK |
328 | ino = autofs4_dentry_ino(new); |
329 | ino->last_used = jiffies; | |
10584211 IK |
330 | dput(path->dentry); |
331 | path->dentry = new; | |
332 | } | |
333 | return path->dentry; | |
334 | } | |
335 | ||
71e469db | 336 | static struct vfsmount *autofs4_d_automount(struct path *path) |
10584211 IK |
337 | { |
338 | struct dentry *dentry = path->dentry; | |
339 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
340 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
341 | int status; | |
342 | ||
343 | DPRINTK("dentry=%p %.*s", | |
344 | dentry, dentry->d_name.len, dentry->d_name.name); | |
345 | ||
346 | /* The daemon never triggers a mount. */ | |
347 | if (autofs4_oz_mode(sbi)) | |
348 | return NULL; | |
349 | ||
350 | /* | |
351 | * If an expire request is pending everyone must wait. | |
352 | * If the expire fails we're still mounted so continue | |
353 | * the follow and return. A return of -EAGAIN (which only | |
354 | * happens with indirect mounts) means the expire completed | |
355 | * and the directory was removed, so just go ahead and try | |
356 | * the mount. | |
357 | */ | |
23bfc2a2 | 358 | status = do_expire_wait(dentry, 0); |
10584211 IK |
359 | if (status && status != -EAGAIN) |
360 | return NULL; | |
361 | ||
362 | /* Callback to the daemon to perform the mount or wait */ | |
363 | spin_lock(&sbi->fs_lock); | |
364 | if (ino->flags & AUTOFS_INF_PENDING) { | |
365 | spin_unlock(&sbi->fs_lock); | |
23bfc2a2 | 366 | status = autofs4_mount_wait(dentry, 0); |
10584211 IK |
367 | if (status) |
368 | return ERR_PTR(status); | |
10584211 IK |
369 | goto done; |
370 | } | |
371 | ||
372 | /* | |
373 | * If the dentry is a symlink it's equivalent to a directory | |
b5b80177 | 374 | * having d_mountpoint() true, so there's no need to call back |
10584211 IK |
375 | * to the daemon. |
376 | */ | |
f55fb0c2 IK |
377 | if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) { |
378 | spin_unlock(&sbi->fs_lock); | |
10584211 | 379 | goto done; |
f55fb0c2 IK |
380 | } |
381 | ||
b5b80177 IK |
382 | if (!d_mountpoint(dentry)) { |
383 | /* | |
384 | * It's possible that user space hasn't removed directories | |
385 | * after umounting a rootless multi-mount, although it | |
386 | * should. For v5 have_submounts() is sufficient to handle | |
387 | * this because the leaves of the directory tree under the | |
388 | * mount never trigger mounts themselves (they have an autofs | |
389 | * trigger mount mounted on them). But v4 pseudo direct mounts | |
3b97dd05 | 390 | * do need the leaves to trigger mounts. In this case we |
b5b80177 IK |
391 | * have no choice but to use the list_empty() check and |
392 | * require user space behave. | |
393 | */ | |
394 | if (sbi->version > 4) { | |
f55fb0c2 IK |
395 | if (have_submounts(dentry)) { |
396 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 397 | goto done; |
f55fb0c2 | 398 | } |
b5b80177 | 399 | } else { |
9d8072e7 PH |
400 | if (!simple_empty(dentry)) { |
401 | spin_unlock(&sbi->fs_lock); | |
b5b80177 | 402 | goto done; |
9d8072e7 | 403 | } |
b5b80177 | 404 | } |
10584211 | 405 | ino->flags |= AUTOFS_INF_PENDING; |
10584211 | 406 | spin_unlock(&sbi->fs_lock); |
23bfc2a2 | 407 | status = autofs4_mount_wait(dentry, 0); |
10584211 IK |
408 | spin_lock(&sbi->fs_lock); |
409 | ino->flags &= ~AUTOFS_INF_PENDING; | |
49999ab2 IK |
410 | if (status) { |
411 | spin_unlock(&sbi->fs_lock); | |
412 | return ERR_PTR(status); | |
413 | } | |
10584211 | 414 | } |
10584211 | 415 | spin_unlock(&sbi->fs_lock); |
f55fb0c2 | 416 | done: |
10584211 IK |
417 | /* Mount succeeded, check if we ended up with a new dentry */ |
418 | dentry = autofs4_mountpoint_changed(path); | |
419 | if (!dentry) | |
420 | return ERR_PTR(-ENOENT); | |
421 | ||
422 | return NULL; | |
423 | } | |
424 | ||
95482986 | 425 | static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk) |
b5b80177 IK |
426 | { |
427 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f55fb0c2 IK |
428 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
429 | int status; | |
b5b80177 IK |
430 | |
431 | DPRINTK("dentry=%p %.*s", | |
432 | dentry, dentry->d_name.len, dentry->d_name.name); | |
433 | ||
434 | /* The daemon never waits. */ | |
1aed3e42 | 435 | if (autofs4_oz_mode(sbi)) { |
b5b80177 IK |
436 | if (!d_mountpoint(dentry)) |
437 | return -EISDIR; | |
438 | return 0; | |
439 | } | |
440 | ||
441 | /* Wait for pending expires */ | |
23bfc2a2 N |
442 | if (do_expire_wait(dentry, rcu_walk) == -ECHILD) |
443 | return -ECHILD; | |
b5b80177 IK |
444 | |
445 | /* | |
446 | * This dentry may be under construction so wait on mount | |
447 | * completion. | |
448 | */ | |
23bfc2a2 | 449 | status = autofs4_mount_wait(dentry, rcu_walk); |
f55fb0c2 IK |
450 | if (status) |
451 | return status; | |
452 | ||
ef16cc59 N |
453 | if (rcu_walk) { |
454 | /* We don't need fs_lock in rcu_walk mode, | |
455 | * just testing 'AUTOFS_INFO_NO_RCU' is enough. | |
456 | * simple_empty() takes a spinlock, so leave it | |
457 | * to last. | |
458 | * We only return -EISDIR when certain this isn't | |
459 | * a mount-trap. | |
23bfc2a2 | 460 | */ |
ef16cc59 N |
461 | struct inode *inode; |
462 | if (ino->flags & (AUTOFS_INF_EXPIRING | AUTOFS_INF_NO_RCU)) | |
463 | return 0; | |
464 | if (d_mountpoint(dentry)) | |
465 | return 0; | |
466 | inode = ACCESS_ONCE(dentry->d_inode); | |
467 | if (inode && S_ISLNK(inode->i_mode)) | |
468 | return -EISDIR; | |
469 | if (list_empty(&dentry->d_subdirs)) | |
470 | return 0; | |
471 | if (!simple_empty(dentry)) | |
472 | return -EISDIR; | |
23bfc2a2 | 473 | return 0; |
ef16cc59 | 474 | } |
23bfc2a2 | 475 | |
f55fb0c2 IK |
476 | spin_lock(&sbi->fs_lock); |
477 | /* | |
478 | * If the dentry has been selected for expire while we slept | |
479 | * on the lock then it might go away. We'll deal with that in | |
480 | * ->d_automount() and wait on a new mount if the expire | |
481 | * succeeds or return here if it doesn't (since there's no | |
482 | * mount to follow with a rootless multi-mount). | |
483 | */ | |
484 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { | |
485 | /* | |
486 | * Any needed mounting has been completed and the path | |
487 | * updated so check if this is a rootless multi-mount so | |
488 | * we can avoid needless calls ->d_automount() and avoid | |
489 | * an incorrect ELOOP error return. | |
490 | */ | |
491 | if ((!d_mountpoint(dentry) && !simple_empty(dentry)) || | |
492 | (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))) | |
493 | status = -EISDIR; | |
494 | } | |
495 | spin_unlock(&sbi->fs_lock); | |
496 | ||
497 | return status; | |
b5b80177 IK |
498 | } |
499 | ||
1da177e4 | 500 | /* Lookups in the root directory */ |
00cd8dd3 | 501 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 LT |
502 | { |
503 | struct autofs_sb_info *sbi; | |
25767378 | 504 | struct autofs_info *ino; |
10584211 | 505 | struct dentry *active; |
1da177e4 | 506 | |
10584211 | 507 | DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name); |
1da177e4 | 508 | |
718c604a | 509 | /* File name too long to exist */ |
1da177e4 | 510 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 511 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
512 | |
513 | sbi = autofs4_sbi(dir->i_sb); | |
718c604a | 514 | |
1da177e4 | 515 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
c0bcc9d5 IK |
516 | current->pid, task_pgrp_nr(current), sbi->catatonic, |
517 | autofs4_oz_mode(sbi)); | |
1da177e4 | 518 | |
6510c9d8 | 519 | active = autofs4_lookup_active(dentry); |
90387c9c | 520 | if (active) { |
10584211 | 521 | return active; |
aa952eb2 | 522 | } else { |
4b1ae27a | 523 | /* |
10584211 IK |
524 | * A dentry that is not within the root can never trigger a |
525 | * mount operation, unless the directory already exists, so we | |
526 | * can return fail immediately. The daemon however does need | |
527 | * to create directories within the file system. | |
4b1ae27a | 528 | */ |
10584211 IK |
529 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
530 | return ERR_PTR(-ENOENT); | |
531 | ||
532 | /* Mark entries in the root as mount triggers */ | |
b650c858 | 533 | if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) |
b5b80177 | 534 | __managed_dentry_set_managed(dentry); |
10584211 | 535 | |
26e6c910 | 536 | ino = autofs4_new_ino(sbi); |
4b1ae27a AV |
537 | if (!ino) |
538 | return ERR_PTR(-ENOMEM); | |
539 | ||
540 | dentry->d_fsdata = ino; | |
541 | ino->dentry = dentry; | |
5f6f4f28 | 542 | |
4b1ae27a AV |
543 | autofs4_add_active(dentry); |
544 | ||
545 | d_instantiate(dentry, NULL); | |
546 | } | |
1da177e4 LT |
547 | return NULL; |
548 | } | |
549 | ||
550 | static int autofs4_dir_symlink(struct inode *dir, | |
551 | struct dentry *dentry, | |
552 | const char *symname) | |
553 | { | |
554 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
555 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 556 | struct autofs_info *p_ino; |
1da177e4 | 557 | struct inode *inode; |
0bf71d4d | 558 | size_t size = strlen(symname); |
1da177e4 LT |
559 | char *cp; |
560 | ||
561 | DPRINTK("%s <- %.*s", symname, | |
562 | dentry->d_name.len, dentry->d_name.name); | |
563 | ||
564 | if (!autofs4_oz_mode(sbi)) | |
565 | return -EACCES; | |
566 | ||
5a37db30 AV |
567 | BUG_ON(!ino); |
568 | ||
26e6c910 | 569 | autofs4_clean_ino(ino); |
1da177e4 | 570 | |
4b1ae27a AV |
571 | autofs4_del_active(dentry); |
572 | ||
0bf71d4d | 573 | cp = kmalloc(size + 1, GFP_KERNEL); |
5a37db30 | 574 | if (!cp) |
25767378 | 575 | return -ENOMEM; |
1da177e4 LT |
576 | |
577 | strcpy(cp, symname); | |
578 | ||
726a5e06 | 579 | inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555); |
25767378 IK |
580 | if (!inode) { |
581 | kfree(cp); | |
582 | if (!dentry->d_fsdata) | |
583 | kfree(ino); | |
584 | return -ENOMEM; | |
585 | } | |
292c5ee8 | 586 | inode->i_private = cp; |
0bf71d4d | 587 | inode->i_size = size; |
1864f7bd | 588 | d_add(dentry, inode); |
1da177e4 | 589 | |
5a37db30 | 590 | dget(dentry); |
1aff3c8b IK |
591 | atomic_inc(&ino->count); |
592 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 593 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 594 | atomic_inc(&p_ino->count); |
1da177e4 LT |
595 | |
596 | dir->i_mtime = CURRENT_TIME; | |
597 | ||
598 | return 0; | |
599 | } | |
600 | ||
601 | /* | |
602 | * NOTE! | |
603 | * | |
604 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
605 | * that the file no longer exists. However, doing that means that the | |
606 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 607 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
608 | * We simply d_drop it and add it to a expiring list in the super block, |
609 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
610 | * |
611 | * If a process is blocked on the dentry waiting for the expire to finish, | |
612 | * it will invalidate the dentry and try to mount with a new one. | |
613 | * | |
614 | * Also see autofs4_dir_rmdir().. | |
615 | */ | |
616 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
617 | { | |
618 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
619 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 620 | struct autofs_info *p_ino; |
1da177e4 LT |
621 | |
622 | /* This allows root to remove symlinks */ | |
d78e53c8 | 623 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
41735818 | 624 | return -EPERM; |
1da177e4 | 625 | |
1aff3c8b IK |
626 | if (atomic_dec_and_test(&ino->count)) { |
627 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 628 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b IK |
629 | atomic_dec(&p_ino->count); |
630 | } | |
1da177e4 LT |
631 | dput(ino->dentry); |
632 | ||
633 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 634 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
635 | |
636 | dir->i_mtime = CURRENT_TIME; | |
637 | ||
e7854723 IK |
638 | spin_lock(&sbi->lookup_lock); |
639 | __autofs4_add_expiring(dentry); | |
0259cb02 | 640 | d_drop(dentry); |
e7854723 | 641 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
642 | |
643 | return 0; | |
644 | } | |
645 | ||
dd89f90d IK |
646 | /* |
647 | * Version 4 of autofs provides a pseudo direct mount implementation | |
648 | * that relies on directories at the leaves of a directory tree under | |
649 | * an indirect mount to trigger mounts. To allow for this we need to | |
650 | * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves | |
651 | * of the directory tree. There is no need to clear the automount flag | |
652 | * following a mount or restore it after an expire because these mounts | |
25985edc | 653 | * are always covered. However, it is necessary to ensure that these |
dd89f90d IK |
654 | * flags are clear on non-empty directories to avoid unnecessary calls |
655 | * during path walks. | |
656 | */ | |
657 | static void autofs_set_leaf_automount_flags(struct dentry *dentry) | |
658 | { | |
659 | struct dentry *parent; | |
660 | ||
661 | /* root and dentrys in the root are already handled */ | |
662 | if (IS_ROOT(dentry->d_parent)) | |
663 | return; | |
664 | ||
665 | managed_dentry_set_managed(dentry); | |
666 | ||
667 | parent = dentry->d_parent; | |
668 | /* only consider parents below dentrys in the root */ | |
669 | if (IS_ROOT(parent->d_parent)) | |
670 | return; | |
671 | managed_dentry_clear_managed(parent); | |
672 | return; | |
673 | } | |
674 | ||
675 | static void autofs_clear_leaf_automount_flags(struct dentry *dentry) | |
676 | { | |
677 | struct list_head *d_child; | |
678 | struct dentry *parent; | |
679 | ||
680 | /* flags for dentrys in the root are handled elsewhere */ | |
681 | if (IS_ROOT(dentry->d_parent)) | |
682 | return; | |
683 | ||
684 | managed_dentry_clear_managed(dentry); | |
685 | ||
686 | parent = dentry->d_parent; | |
687 | /* only consider parents below dentrys in the root */ | |
688 | if (IS_ROOT(parent->d_parent)) | |
689 | return; | |
690 | d_child = &dentry->d_u.d_child; | |
691 | /* Set parent managed if it's becoming empty */ | |
692 | if (d_child->next == &parent->d_subdirs && | |
693 | d_child->prev == &parent->d_subdirs) | |
694 | managed_dentry_set_managed(parent); | |
695 | return; | |
696 | } | |
697 | ||
1da177e4 LT |
698 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
699 | { | |
700 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
701 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 702 | struct autofs_info *p_ino; |
1da177e4 | 703 | |
f50b6f86 IK |
704 | DPRINTK("dentry %p, removing %.*s", |
705 | dentry, dentry->d_name.len, dentry->d_name.name); | |
706 | ||
1da177e4 LT |
707 | if (!autofs4_oz_mode(sbi)) |
708 | return -EACCES; | |
709 | ||
2fd6b7f5 | 710 | spin_lock(&sbi->lookup_lock); |
0259cb02 | 711 | if (!simple_empty(dentry)) { |
2fd6b7f5 | 712 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
713 | return -ENOTEMPTY; |
714 | } | |
2fd6b7f5 | 715 | __autofs4_add_expiring(dentry); |
0259cb02 | 716 | d_drop(dentry); |
e7854723 | 717 | spin_unlock(&sbi->lookup_lock); |
1da177e4 | 718 | |
dd89f90d IK |
719 | if (sbi->version < 5) |
720 | autofs_clear_leaf_automount_flags(dentry); | |
721 | ||
1aff3c8b IK |
722 | if (atomic_dec_and_test(&ino->count)) { |
723 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
724 | if (p_ino && dentry->d_parent != dentry) | |
725 | atomic_dec(&p_ino->count); | |
726 | } | |
1da177e4 | 727 | dput(ino->dentry); |
1da177e4 | 728 | dentry->d_inode->i_size = 0; |
ce71ec36 | 729 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
730 | |
731 | if (dir->i_nlink) | |
9a53c3a7 | 732 | drop_nlink(dir); |
1da177e4 LT |
733 | |
734 | return 0; | |
735 | } | |
736 | ||
18bb1db3 | 737 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
738 | { |
739 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
740 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 741 | struct autofs_info *p_ino; |
1da177e4 LT |
742 | struct inode *inode; |
743 | ||
d78e53c8 | 744 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
745 | return -EACCES; |
746 | ||
747 | DPRINTK("dentry %p, creating %.*s", | |
748 | dentry, dentry->d_name.len, dentry->d_name.name); | |
749 | ||
5a37db30 AV |
750 | BUG_ON(!ino); |
751 | ||
26e6c910 | 752 | autofs4_clean_ino(ino); |
25767378 | 753 | |
4b1ae27a AV |
754 | autofs4_del_active(dentry); |
755 | ||
726a5e06 | 756 | inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555); |
5a37db30 | 757 | if (!inode) |
25767378 | 758 | return -ENOMEM; |
1864f7bd | 759 | d_add(dentry, inode); |
1da177e4 | 760 | |
dd89f90d IK |
761 | if (sbi->version < 5) |
762 | autofs_set_leaf_automount_flags(dentry); | |
763 | ||
5a37db30 | 764 | dget(dentry); |
1aff3c8b IK |
765 | atomic_inc(&ino->count); |
766 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
c24930a9 | 767 | if (p_ino && !IS_ROOT(dentry)) |
1aff3c8b | 768 | atomic_inc(&p_ino->count); |
d8c76e6f | 769 | inc_nlink(dir); |
1da177e4 LT |
770 | dir->i_mtime = CURRENT_TIME; |
771 | ||
772 | return 0; | |
773 | } | |
774 | ||
775 | /* Get/set timeout ioctl() operation */ | |
c9243f5b AB |
776 | #ifdef CONFIG_COMPAT |
777 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, | |
778 | compat_ulong_t __user *p) | |
779 | { | |
780 | int rv; | |
781 | unsigned long ntimeout; | |
782 | ||
783 | if ((rv = get_user(ntimeout, p)) || | |
784 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
785 | return rv; | |
786 | ||
787 | if (ntimeout > UINT_MAX/HZ) | |
788 | sbi->exp_timeout = 0; | |
789 | else | |
790 | sbi->exp_timeout = ntimeout * HZ; | |
791 | ||
792 | return 0; | |
793 | } | |
794 | #endif | |
795 | ||
1da177e4 LT |
796 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
797 | unsigned long __user *p) | |
798 | { | |
799 | int rv; | |
800 | unsigned long ntimeout; | |
801 | ||
d78e53c8 SB |
802 | if ((rv = get_user(ntimeout, p)) || |
803 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
804 | return rv; |
805 | ||
d78e53c8 | 806 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
807 | sbi->exp_timeout = 0; |
808 | else | |
809 | sbi->exp_timeout = ntimeout * HZ; | |
810 | ||
811 | return 0; | |
812 | } | |
813 | ||
814 | /* Return protocol version */ | |
815 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
816 | { | |
817 | return put_user(sbi->version, p); | |
818 | } | |
819 | ||
820 | /* Return protocol sub version */ | |
821 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
822 | { | |
823 | return put_user(sbi->sub_version, p); | |
824 | } | |
825 | ||
1da177e4 LT |
826 | /* |
827 | * Tells the daemon whether it can umount the autofs mount. | |
828 | */ | |
829 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
830 | { | |
831 | int status = 0; | |
832 | ||
e3474a8e | 833 | if (may_umount(mnt)) |
1da177e4 LT |
834 | status = 1; |
835 | ||
836 | DPRINTK("returning %d", status); | |
837 | ||
838 | status = put_user(status, p); | |
839 | ||
840 | return status; | |
841 | } | |
842 | ||
843 | /* Identify autofs4_dentries - this is so we can tell if there's | |
844 | an extra dentry refcount or not. We only hold a refcount on the | |
845 | dentry if its non-negative (ie, d_inode != NULL) | |
846 | */ | |
847 | int is_autofs4_dentry(struct dentry *dentry) | |
848 | { | |
849 | return dentry && dentry->d_inode && | |
b650c858 | 850 | dentry->d_op == &autofs4_dentry_operations && |
1da177e4 LT |
851 | dentry->d_fsdata != NULL; |
852 | } | |
853 | ||
854 | /* | |
855 | * ioctl()'s on the root directory is the chief method for the daemon to | |
856 | * generate kernel reactions | |
857 | */ | |
3663df70 FW |
858 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
859 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
860 | { |
861 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
862 | void __user *p = (void __user *)arg; | |
863 | ||
864 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 865 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 866 | |
d78e53c8 SB |
867 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
868 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
869 | return -ENOTTY; |
870 | ||
d78e53c8 | 871 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
872 | return -EPERM; |
873 | ||
874 | switch(cmd) { | |
875 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
876 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
877 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
878 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
879 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
880 | autofs4_catatonic_mode(sbi); | |
881 | return 0; | |
882 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
883 | return autofs4_get_protover(sbi, p); | |
884 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
885 | return autofs4_get_protosubver(sbi, p); | |
886 | case AUTOFS_IOC_SETTIMEOUT: | |
887 | return autofs4_get_set_timeout(sbi, p); | |
c9243f5b AB |
888 | #ifdef CONFIG_COMPAT |
889 | case AUTOFS_IOC_SETTIMEOUT32: | |
890 | return autofs4_compat_get_set_timeout(sbi, p); | |
891 | #endif | |
1da177e4 | 892 | |
1da177e4 | 893 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 894 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
895 | |
896 | /* return a single thing to expire */ | |
897 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 898 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
899 | /* same as above, but can send multiple expires through pipe */ |
900 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 901 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
902 | |
903 | default: | |
904 | return -ENOSYS; | |
905 | } | |
906 | } | |
3663df70 FW |
907 | |
908 | static long autofs4_root_ioctl(struct file *filp, | |
909 | unsigned int cmd, unsigned long arg) | |
910 | { | |
496ad9aa | 911 | struct inode *inode = file_inode(filp); |
de47de74 | 912 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
3663df70 | 913 | } |
c9243f5b AB |
914 | |
915 | #ifdef CONFIG_COMPAT | |
916 | static long autofs4_root_compat_ioctl(struct file *filp, | |
917 | unsigned int cmd, unsigned long arg) | |
918 | { | |
496ad9aa | 919 | struct inode *inode = file_inode(filp); |
c9243f5b AB |
920 | int ret; |
921 | ||
c9243f5b AB |
922 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
923 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); | |
924 | else | |
925 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, | |
926 | (unsigned long)compat_ptr(arg)); | |
c9243f5b AB |
927 | |
928 | return ret; | |
929 | } | |
930 | #endif |