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Commit | Line | Data |
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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 | 38 | static struct vfsmount *autofs4_d_automount(struct path *); |
ab90911f | 39 | static int autofs4_d_manage(struct dentry *, bool, 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); | |
1da177e4 | 154 | if (inf) { |
f50b6f86 | 155 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); |
f50b6f86 | 156 | if (sbi) { |
5f6f4f28 | 157 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
158 | if (!list_empty(&inf->active)) |
159 | list_del(&inf->active); | |
5f6f4f28 IK |
160 | if (!list_empty(&inf->expiring)) |
161 | list_del(&inf->expiring); | |
162 | spin_unlock(&sbi->lookup_lock); | |
f50b6f86 | 163 | } |
1da177e4 LT |
164 | autofs4_free_ino(inf); |
165 | } | |
166 | } | |
167 | ||
6510c9d8 | 168 | static struct dentry *autofs4_lookup_active(struct dentry *dentry) |
25767378 | 169 | { |
6510c9d8 IK |
170 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
171 | struct dentry *parent = dentry->d_parent; | |
172 | struct qstr *name = &dentry->d_name; | |
25767378 IK |
173 | unsigned int len = name->len; |
174 | unsigned int hash = name->hash; | |
175 | const unsigned char *str = name->name; | |
176 | struct list_head *p, *head; | |
177 | ||
b5c84bf6 | 178 | spin_lock(&autofs4_lock); |
25767378 IK |
179 | spin_lock(&sbi->lookup_lock); |
180 | head = &sbi->active_list; | |
181 | list_for_each(p, head) { | |
182 | struct autofs_info *ino; | |
e4d5ade7 | 183 | struct dentry *active; |
25767378 IK |
184 | struct qstr *qstr; |
185 | ||
186 | ino = list_entry(p, struct autofs_info, active); | |
e4d5ade7 | 187 | active = ino->dentry; |
25767378 | 188 | |
e4d5ade7 | 189 | spin_lock(&active->d_lock); |
25767378 IK |
190 | |
191 | /* Already gone? */ | |
b7ab39f6 | 192 | if (active->d_count == 0) |
25767378 IK |
193 | goto next; |
194 | ||
e4d5ade7 | 195 | qstr = &active->d_name; |
25767378 | 196 | |
e4d5ade7 | 197 | if (active->d_name.hash != hash) |
25767378 | 198 | goto next; |
e4d5ade7 | 199 | if (active->d_parent != parent) |
25767378 IK |
200 | goto next; |
201 | ||
202 | if (qstr->len != len) | |
203 | goto next; | |
204 | if (memcmp(qstr->name, str, len)) | |
205 | goto next; | |
206 | ||
4b1ae27a | 207 | if (d_unhashed(active)) { |
b7ab39f6 | 208 | dget_dlock(active); |
4b1ae27a AV |
209 | spin_unlock(&active->d_lock); |
210 | spin_unlock(&sbi->lookup_lock); | |
b5c84bf6 | 211 | spin_unlock(&autofs4_lock); |
4b1ae27a AV |
212 | return active; |
213 | } | |
25767378 | 214 | next: |
e4d5ade7 | 215 | spin_unlock(&active->d_lock); |
25767378 IK |
216 | } |
217 | spin_unlock(&sbi->lookup_lock); | |
b5c84bf6 | 218 | spin_unlock(&autofs4_lock); |
25767378 IK |
219 | |
220 | return NULL; | |
221 | } | |
222 | ||
6510c9d8 | 223 | static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) |
f50b6f86 | 224 | { |
6510c9d8 IK |
225 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
226 | struct dentry *parent = dentry->d_parent; | |
227 | struct qstr *name = &dentry->d_name; | |
f50b6f86 IK |
228 | unsigned int len = name->len; |
229 | unsigned int hash = name->hash; | |
230 | const unsigned char *str = name->name; | |
231 | struct list_head *p, *head; | |
232 | ||
b5c84bf6 | 233 | spin_lock(&autofs4_lock); |
5f6f4f28 IK |
234 | spin_lock(&sbi->lookup_lock); |
235 | head = &sbi->expiring_list; | |
f50b6f86 IK |
236 | list_for_each(p, head) { |
237 | struct autofs_info *ino; | |
cb4b492a | 238 | struct dentry *expiring; |
f50b6f86 IK |
239 | struct qstr *qstr; |
240 | ||
5f6f4f28 | 241 | ino = list_entry(p, struct autofs_info, expiring); |
cb4b492a | 242 | expiring = ino->dentry; |
f50b6f86 | 243 | |
cb4b492a | 244 | spin_lock(&expiring->d_lock); |
f50b6f86 IK |
245 | |
246 | /* Bad luck, we've already been dentry_iput */ | |
cb4b492a | 247 | if (!expiring->d_inode) |
f50b6f86 IK |
248 | goto next; |
249 | ||
cb4b492a | 250 | qstr = &expiring->d_name; |
f50b6f86 | 251 | |
cb4b492a | 252 | if (expiring->d_name.hash != hash) |
f50b6f86 | 253 | goto next; |
cb4b492a | 254 | if (expiring->d_parent != parent) |
f50b6f86 IK |
255 | goto next; |
256 | ||
257 | if (qstr->len != len) | |
258 | goto next; | |
259 | if (memcmp(qstr->name, str, len)) | |
260 | goto next; | |
261 | ||
4b1ae27a | 262 | if (d_unhashed(expiring)) { |
b7ab39f6 | 263 | dget_dlock(expiring); |
4b1ae27a AV |
264 | spin_unlock(&expiring->d_lock); |
265 | spin_unlock(&sbi->lookup_lock); | |
b5c84bf6 | 266 | spin_unlock(&autofs4_lock); |
4b1ae27a AV |
267 | return expiring; |
268 | } | |
f50b6f86 | 269 | next: |
cb4b492a | 270 | spin_unlock(&expiring->d_lock); |
f50b6f86 | 271 | } |
5f6f4f28 | 272 | spin_unlock(&sbi->lookup_lock); |
b5c84bf6 | 273 | spin_unlock(&autofs4_lock); |
f50b6f86 IK |
274 | |
275 | return NULL; | |
276 | } | |
277 | ||
10584211 IK |
278 | static int autofs4_mount_wait(struct dentry *dentry) |
279 | { | |
280 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
281 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
282 | int status; | |
283 | ||
284 | if (ino->flags & AUTOFS_INF_PENDING) { | |
285 | DPRINTK("waiting for mount name=%.*s", | |
286 | dentry->d_name.len, dentry->d_name.name); | |
287 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
288 | DPRINTK("mount wait done status=%d", status); | |
289 | ino->last_used = jiffies; | |
290 | return status; | |
291 | } | |
292 | return 0; | |
293 | } | |
294 | ||
295 | static int do_expire_wait(struct dentry *dentry) | |
296 | { | |
297 | struct dentry *expiring; | |
298 | ||
299 | expiring = autofs4_lookup_expiring(dentry); | |
300 | if (!expiring) | |
301 | return autofs4_expire_wait(dentry); | |
302 | else { | |
303 | /* | |
304 | * If we are racing with expire the request might not | |
305 | * be quite complete, but the directory has been removed | |
306 | * so it must have been successful, just wait for it. | |
307 | */ | |
308 | autofs4_expire_wait(expiring); | |
309 | autofs4_del_expiring(expiring); | |
310 | dput(expiring); | |
311 | } | |
312 | return 0; | |
313 | } | |
314 | ||
315 | static struct dentry *autofs4_mountpoint_changed(struct path *path) | |
316 | { | |
317 | struct dentry *dentry = path->dentry; | |
318 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
319 | ||
320 | /* | |
321 | * If this is an indirect mount the dentry could have gone away | |
322 | * as a result of an expire and a new one created. | |
323 | */ | |
324 | if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { | |
325 | struct dentry *parent = dentry->d_parent; | |
326 | struct dentry *new = d_lookup(parent, &dentry->d_name); | |
327 | if (!new) | |
328 | return NULL; | |
329 | dput(path->dentry); | |
330 | path->dentry = new; | |
331 | } | |
332 | return path->dentry; | |
333 | } | |
334 | ||
71e469db | 335 | static struct vfsmount *autofs4_d_automount(struct path *path) |
10584211 IK |
336 | { |
337 | struct dentry *dentry = path->dentry; | |
338 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
339 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
340 | int status; | |
341 | ||
342 | DPRINTK("dentry=%p %.*s", | |
343 | dentry, dentry->d_name.len, dentry->d_name.name); | |
344 | ||
b5b80177 IK |
345 | /* |
346 | * Someone may have manually umounted this or it was a submount | |
347 | * that has gone away. | |
348 | */ | |
349 | spin_lock(&dentry->d_lock); | |
350 | if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { | |
351 | if (!(dentry->d_flags & DCACHE_MANAGE_TRANSIT) && | |
352 | (dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) | |
353 | __managed_dentry_set_transit(path->dentry); | |
354 | } | |
355 | spin_unlock(&dentry->d_lock); | |
356 | ||
10584211 IK |
357 | /* The daemon never triggers a mount. */ |
358 | if (autofs4_oz_mode(sbi)) | |
359 | return NULL; | |
360 | ||
361 | /* | |
362 | * If an expire request is pending everyone must wait. | |
363 | * If the expire fails we're still mounted so continue | |
364 | * the follow and return. A return of -EAGAIN (which only | |
365 | * happens with indirect mounts) means the expire completed | |
366 | * and the directory was removed, so just go ahead and try | |
367 | * the mount. | |
368 | */ | |
369 | status = do_expire_wait(dentry); | |
370 | if (status && status != -EAGAIN) | |
371 | return NULL; | |
372 | ||
373 | /* Callback to the daemon to perform the mount or wait */ | |
374 | spin_lock(&sbi->fs_lock); | |
375 | if (ino->flags & AUTOFS_INF_PENDING) { | |
376 | spin_unlock(&sbi->fs_lock); | |
377 | status = autofs4_mount_wait(dentry); | |
378 | if (status) | |
379 | return ERR_PTR(status); | |
380 | spin_lock(&sbi->fs_lock); | |
381 | goto done; | |
382 | } | |
383 | ||
384 | /* | |
385 | * If the dentry is a symlink it's equivalent to a directory | |
b5b80177 | 386 | * having d_mountpoint() true, so there's no need to call back |
10584211 IK |
387 | * to the daemon. |
388 | */ | |
389 | if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)) | |
390 | goto done; | |
b5b80177 IK |
391 | if (!d_mountpoint(dentry)) { |
392 | /* | |
393 | * It's possible that user space hasn't removed directories | |
394 | * after umounting a rootless multi-mount, although it | |
395 | * should. For v5 have_submounts() is sufficient to handle | |
396 | * this because the leaves of the directory tree under the | |
397 | * mount never trigger mounts themselves (they have an autofs | |
398 | * trigger mount mounted on them). But v4 pseudo direct mounts | |
399 | * do need the leaves to to trigger mounts. In this case we | |
400 | * have no choice but to use the list_empty() check and | |
401 | * require user space behave. | |
402 | */ | |
403 | if (sbi->version > 4) { | |
404 | if (have_submounts(dentry)) | |
405 | goto done; | |
406 | } else { | |
407 | spin_lock(&dentry->d_lock); | |
408 | if (!list_empty(&dentry->d_subdirs)) { | |
409 | spin_unlock(&dentry->d_lock); | |
410 | goto done; | |
411 | } | |
412 | spin_unlock(&dentry->d_lock); | |
413 | } | |
10584211 | 414 | ino->flags |= AUTOFS_INF_PENDING; |
10584211 IK |
415 | spin_unlock(&sbi->fs_lock); |
416 | status = autofs4_mount_wait(dentry); | |
417 | if (status) | |
418 | return ERR_PTR(status); | |
419 | spin_lock(&sbi->fs_lock); | |
420 | ino->flags &= ~AUTOFS_INF_PENDING; | |
10584211 | 421 | } |
10584211 | 422 | done: |
b5b80177 IK |
423 | if (!(ino->flags & AUTOFS_INF_EXPIRING)) { |
424 | /* | |
425 | * Any needed mounting has been completed and the path updated | |
426 | * so turn this into a normal dentry so we don't continually | |
427 | * call ->d_automount() and ->d_manage(). | |
428 | */ | |
429 | spin_lock(&dentry->d_lock); | |
430 | __managed_dentry_clear_transit(dentry); | |
431 | /* | |
432 | * Only clear DMANAGED_AUTOMOUNT for rootless multi-mounts and | |
433 | * symlinks as in all other cases the dentry will be covered by | |
434 | * an actual mount so ->d_automount() won't be called during | |
435 | * the follow. | |
436 | */ | |
437 | if ((!d_mountpoint(dentry) && | |
438 | !list_empty(&dentry->d_subdirs)) || | |
439 | (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))) | |
440 | __managed_dentry_clear_automount(dentry); | |
441 | spin_unlock(&dentry->d_lock); | |
442 | } | |
10584211 IK |
443 | spin_unlock(&sbi->fs_lock); |
444 | ||
445 | /* Mount succeeded, check if we ended up with a new dentry */ | |
446 | dentry = autofs4_mountpoint_changed(path); | |
447 | if (!dentry) | |
448 | return ERR_PTR(-ENOENT); | |
449 | ||
450 | return NULL; | |
451 | } | |
452 | ||
ab90911f | 453 | int autofs4_d_manage(struct dentry *dentry, bool mounting_here, bool rcu_walk) |
b5b80177 IK |
454 | { |
455 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
456 | ||
457 | DPRINTK("dentry=%p %.*s", | |
458 | dentry, dentry->d_name.len, dentry->d_name.name); | |
459 | ||
460 | /* The daemon never waits. */ | |
461 | if (autofs4_oz_mode(sbi) || mounting_here) { | |
462 | if (!d_mountpoint(dentry)) | |
463 | return -EISDIR; | |
464 | return 0; | |
465 | } | |
466 | ||
ab90911f DH |
467 | /* We need to sleep, so we need pathwalk to be in ref-mode */ |
468 | if (rcu_walk) | |
469 | return -ECHILD; | |
470 | ||
b5b80177 IK |
471 | /* Wait for pending expires */ |
472 | do_expire_wait(dentry); | |
473 | ||
474 | /* | |
475 | * This dentry may be under construction so wait on mount | |
476 | * completion. | |
477 | */ | |
478 | return autofs4_mount_wait(dentry); | |
479 | } | |
480 | ||
1da177e4 LT |
481 | /* Lookups in the root directory */ |
482 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
483 | { | |
484 | struct autofs_sb_info *sbi; | |
25767378 | 485 | struct autofs_info *ino; |
10584211 | 486 | struct dentry *active; |
1da177e4 | 487 | |
10584211 | 488 | DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name); |
1da177e4 | 489 | |
718c604a | 490 | /* File name too long to exist */ |
1da177e4 | 491 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 492 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
493 | |
494 | sbi = autofs4_sbi(dir->i_sb); | |
718c604a | 495 | |
1da177e4 | 496 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
10584211 | 497 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); |
1da177e4 | 498 | |
6510c9d8 | 499 | active = autofs4_lookup_active(dentry); |
90387c9c | 500 | if (active) { |
10584211 | 501 | return active; |
aa952eb2 | 502 | } else { |
71e469db | 503 | d_set_d_op(dentry, &autofs4_dentry_operations); |
4b1ae27a AV |
504 | |
505 | /* | |
10584211 IK |
506 | * A dentry that is not within the root can never trigger a |
507 | * mount operation, unless the directory already exists, so we | |
508 | * can return fail immediately. The daemon however does need | |
509 | * to create directories within the file system. | |
4b1ae27a | 510 | */ |
10584211 IK |
511 | if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) |
512 | return ERR_PTR(-ENOENT); | |
513 | ||
514 | /* Mark entries in the root as mount triggers */ | |
515 | if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) { | |
71e469db | 516 | d_set_d_op(dentry, &autofs4_mount_dentry_operations); |
b5b80177 | 517 | __managed_dentry_set_managed(dentry); |
10584211 IK |
518 | } |
519 | ||
4b1ae27a AV |
520 | ino = autofs4_init_ino(NULL, sbi, 0555); |
521 | if (!ino) | |
522 | return ERR_PTR(-ENOMEM); | |
523 | ||
524 | dentry->d_fsdata = ino; | |
525 | ino->dentry = dentry; | |
5f6f4f28 | 526 | |
4b1ae27a AV |
527 | autofs4_add_active(dentry); |
528 | ||
529 | d_instantiate(dentry, NULL); | |
530 | } | |
1da177e4 LT |
531 | return NULL; |
532 | } | |
533 | ||
534 | static int autofs4_dir_symlink(struct inode *dir, | |
535 | struct dentry *dentry, | |
536 | const char *symname) | |
537 | { | |
538 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
539 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 540 | struct autofs_info *p_ino; |
1da177e4 LT |
541 | struct inode *inode; |
542 | char *cp; | |
543 | ||
544 | DPRINTK("%s <- %.*s", symname, | |
545 | dentry->d_name.len, dentry->d_name.name); | |
546 | ||
547 | if (!autofs4_oz_mode(sbi)) | |
548 | return -EACCES; | |
549 | ||
550 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
25767378 IK |
551 | if (!ino) |
552 | return -ENOMEM; | |
1da177e4 | 553 | |
4b1ae27a AV |
554 | autofs4_del_active(dentry); |
555 | ||
ef581a74 | 556 | ino->size = strlen(symname); |
25767378 IK |
557 | cp = kmalloc(ino->size + 1, GFP_KERNEL); |
558 | if (!cp) { | |
559 | if (!dentry->d_fsdata) | |
560 | kfree(ino); | |
561 | return -ENOMEM; | |
1da177e4 LT |
562 | } |
563 | ||
564 | strcpy(cp, symname); | |
565 | ||
566 | inode = autofs4_get_inode(dir->i_sb, ino); | |
25767378 IK |
567 | if (!inode) { |
568 | kfree(cp); | |
569 | if (!dentry->d_fsdata) | |
570 | kfree(ino); | |
571 | return -ENOMEM; | |
572 | } | |
1864f7bd | 573 | d_add(dentry, inode); |
1da177e4 | 574 | |
71e469db IK |
575 | d_set_d_op(dentry, &autofs4_dentry_operations); |
576 | ||
1da177e4 LT |
577 | dentry->d_fsdata = ino; |
578 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
579 | atomic_inc(&ino->count); |
580 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
581 | if (p_ino && dentry->d_parent != dentry) | |
582 | atomic_inc(&p_ino->count); | |
1da177e4 | 583 | |
25767378 | 584 | ino->u.symlink = cp; |
1da177e4 LT |
585 | dir->i_mtime = CURRENT_TIME; |
586 | ||
587 | return 0; | |
588 | } | |
589 | ||
590 | /* | |
591 | * NOTE! | |
592 | * | |
593 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
594 | * that the file no longer exists. However, doing that means that the | |
595 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 596 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
597 | * We simply d_drop it and add it to a expiring list in the super block, |
598 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
599 | * |
600 | * If a process is blocked on the dentry waiting for the expire to finish, | |
601 | * it will invalidate the dentry and try to mount with a new one. | |
602 | * | |
603 | * Also see autofs4_dir_rmdir().. | |
604 | */ | |
605 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
606 | { | |
607 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
608 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 609 | struct autofs_info *p_ino; |
1da177e4 LT |
610 | |
611 | /* This allows root to remove symlinks */ | |
d78e53c8 | 612 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
613 | return -EACCES; |
614 | ||
1aff3c8b IK |
615 | if (atomic_dec_and_test(&ino->count)) { |
616 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
617 | if (p_ino && dentry->d_parent != dentry) | |
618 | atomic_dec(&p_ino->count); | |
619 | } | |
1da177e4 LT |
620 | dput(ino->dentry); |
621 | ||
622 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 623 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
624 | |
625 | dir->i_mtime = CURRENT_TIME; | |
626 | ||
b5c84bf6 | 627 | spin_lock(&autofs4_lock); |
4b1ae27a | 628 | autofs4_add_expiring(dentry); |
f50b6f86 IK |
629 | spin_lock(&dentry->d_lock); |
630 | __d_drop(dentry); | |
631 | spin_unlock(&dentry->d_lock); | |
b5c84bf6 | 632 | spin_unlock(&autofs4_lock); |
1da177e4 LT |
633 | |
634 | return 0; | |
635 | } | |
636 | ||
dd89f90d IK |
637 | /* |
638 | * Version 4 of autofs provides a pseudo direct mount implementation | |
639 | * that relies on directories at the leaves of a directory tree under | |
640 | * an indirect mount to trigger mounts. To allow for this we need to | |
641 | * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves | |
642 | * of the directory tree. There is no need to clear the automount flag | |
643 | * following a mount or restore it after an expire because these mounts | |
644 | * are always covered. However, it is neccessary to ensure that these | |
645 | * flags are clear on non-empty directories to avoid unnecessary calls | |
646 | * during path walks. | |
647 | */ | |
648 | static void autofs_set_leaf_automount_flags(struct dentry *dentry) | |
649 | { | |
650 | struct dentry *parent; | |
651 | ||
652 | /* root and dentrys in the root are already handled */ | |
653 | if (IS_ROOT(dentry->d_parent)) | |
654 | return; | |
655 | ||
656 | managed_dentry_set_managed(dentry); | |
657 | ||
658 | parent = dentry->d_parent; | |
659 | /* only consider parents below dentrys in the root */ | |
660 | if (IS_ROOT(parent->d_parent)) | |
661 | return; | |
662 | managed_dentry_clear_managed(parent); | |
663 | return; | |
664 | } | |
665 | ||
666 | static void autofs_clear_leaf_automount_flags(struct dentry *dentry) | |
667 | { | |
668 | struct list_head *d_child; | |
669 | struct dentry *parent; | |
670 | ||
671 | /* flags for dentrys in the root are handled elsewhere */ | |
672 | if (IS_ROOT(dentry->d_parent)) | |
673 | return; | |
674 | ||
675 | managed_dentry_clear_managed(dentry); | |
676 | ||
677 | parent = dentry->d_parent; | |
678 | /* only consider parents below dentrys in the root */ | |
679 | if (IS_ROOT(parent->d_parent)) | |
680 | return; | |
681 | d_child = &dentry->d_u.d_child; | |
682 | /* Set parent managed if it's becoming empty */ | |
683 | if (d_child->next == &parent->d_subdirs && | |
684 | d_child->prev == &parent->d_subdirs) | |
685 | managed_dentry_set_managed(parent); | |
686 | return; | |
687 | } | |
688 | ||
1da177e4 LT |
689 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) |
690 | { | |
691 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
692 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 693 | struct autofs_info *p_ino; |
1da177e4 | 694 | |
f50b6f86 IK |
695 | DPRINTK("dentry %p, removing %.*s", |
696 | dentry, dentry->d_name.len, dentry->d_name.name); | |
697 | ||
1da177e4 LT |
698 | if (!autofs4_oz_mode(sbi)) |
699 | return -EACCES; | |
700 | ||
b5c84bf6 | 701 | spin_lock(&autofs4_lock); |
2fd6b7f5 NP |
702 | spin_lock(&sbi->lookup_lock); |
703 | spin_lock(&dentry->d_lock); | |
1da177e4 | 704 | if (!list_empty(&dentry->d_subdirs)) { |
2fd6b7f5 NP |
705 | spin_unlock(&dentry->d_lock); |
706 | spin_unlock(&sbi->lookup_lock); | |
b5c84bf6 | 707 | spin_unlock(&autofs4_lock); |
1da177e4 LT |
708 | return -ENOTEMPTY; |
709 | } | |
2fd6b7f5 NP |
710 | __autofs4_add_expiring(dentry); |
711 | spin_unlock(&sbi->lookup_lock); | |
1da177e4 LT |
712 | __d_drop(dentry); |
713 | spin_unlock(&dentry->d_lock); | |
b5c84bf6 | 714 | spin_unlock(&autofs4_lock); |
1da177e4 | 715 | |
dd89f90d IK |
716 | if (sbi->version < 5) |
717 | autofs_clear_leaf_automount_flags(dentry); | |
718 | ||
1aff3c8b IK |
719 | if (atomic_dec_and_test(&ino->count)) { |
720 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
721 | if (p_ino && dentry->d_parent != dentry) | |
722 | atomic_dec(&p_ino->count); | |
723 | } | |
1da177e4 | 724 | dput(ino->dentry); |
1da177e4 | 725 | dentry->d_inode->i_size = 0; |
ce71ec36 | 726 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
727 | |
728 | if (dir->i_nlink) | |
9a53c3a7 | 729 | drop_nlink(dir); |
1da177e4 LT |
730 | |
731 | return 0; | |
732 | } | |
733 | ||
734 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
735 | { | |
736 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
737 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 738 | struct autofs_info *p_ino; |
1da177e4 LT |
739 | struct inode *inode; |
740 | ||
d78e53c8 | 741 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
742 | return -EACCES; |
743 | ||
744 | DPRINTK("dentry %p, creating %.*s", | |
745 | dentry, dentry->d_name.len, dentry->d_name.name); | |
746 | ||
747 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
25767378 IK |
748 | if (!ino) |
749 | return -ENOMEM; | |
750 | ||
4b1ae27a AV |
751 | autofs4_del_active(dentry); |
752 | ||
1da177e4 | 753 | inode = autofs4_get_inode(dir->i_sb, ino); |
25767378 IK |
754 | if (!inode) { |
755 | if (!dentry->d_fsdata) | |
756 | kfree(ino); | |
757 | return -ENOMEM; | |
758 | } | |
1864f7bd | 759 | d_add(dentry, inode); |
1da177e4 | 760 | |
dd89f90d IK |
761 | if (sbi->version < 5) |
762 | autofs_set_leaf_automount_flags(dentry); | |
763 | ||
1da177e4 LT |
764 | dentry->d_fsdata = ino; |
765 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
766 | atomic_inc(&ino->count); |
767 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
768 | if (p_ino && dentry->d_parent != dentry) | |
769 | atomic_inc(&p_ino->count); | |
d8c76e6f | 770 | inc_nlink(dir); |
1da177e4 LT |
771 | dir->i_mtime = CURRENT_TIME; |
772 | ||
773 | return 0; | |
774 | } | |
775 | ||
776 | /* Get/set timeout ioctl() operation */ | |
c9243f5b AB |
777 | #ifdef CONFIG_COMPAT |
778 | static inline int autofs4_compat_get_set_timeout(struct autofs_sb_info *sbi, | |
779 | compat_ulong_t __user *p) | |
780 | { | |
781 | int rv; | |
782 | unsigned long ntimeout; | |
783 | ||
784 | if ((rv = get_user(ntimeout, p)) || | |
785 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
786 | return rv; | |
787 | ||
788 | if (ntimeout > UINT_MAX/HZ) | |
789 | sbi->exp_timeout = 0; | |
790 | else | |
791 | sbi->exp_timeout = ntimeout * HZ; | |
792 | ||
793 | return 0; | |
794 | } | |
795 | #endif | |
796 | ||
1da177e4 LT |
797 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, |
798 | unsigned long __user *p) | |
799 | { | |
800 | int rv; | |
801 | unsigned long ntimeout; | |
802 | ||
d78e53c8 SB |
803 | if ((rv = get_user(ntimeout, p)) || |
804 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
805 | return rv; |
806 | ||
d78e53c8 | 807 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
808 | sbi->exp_timeout = 0; |
809 | else | |
810 | sbi->exp_timeout = ntimeout * HZ; | |
811 | ||
812 | return 0; | |
813 | } | |
814 | ||
815 | /* Return protocol version */ | |
816 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
817 | { | |
818 | return put_user(sbi->version, p); | |
819 | } | |
820 | ||
821 | /* Return protocol sub version */ | |
822 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
823 | { | |
824 | return put_user(sbi->sub_version, p); | |
825 | } | |
826 | ||
1da177e4 LT |
827 | /* |
828 | * Tells the daemon whether it can umount the autofs mount. | |
829 | */ | |
830 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
831 | { | |
832 | int status = 0; | |
833 | ||
e3474a8e | 834 | if (may_umount(mnt)) |
1da177e4 LT |
835 | status = 1; |
836 | ||
837 | DPRINTK("returning %d", status); | |
838 | ||
839 | status = put_user(status, p); | |
840 | ||
841 | return status; | |
842 | } | |
843 | ||
844 | /* Identify autofs4_dentries - this is so we can tell if there's | |
845 | an extra dentry refcount or not. We only hold a refcount on the | |
846 | dentry if its non-negative (ie, d_inode != NULL) | |
847 | */ | |
848 | int is_autofs4_dentry(struct dentry *dentry) | |
849 | { | |
850 | return dentry && dentry->d_inode && | |
71e469db | 851 | (dentry->d_op == &autofs4_mount_dentry_operations || |
1da177e4 LT |
852 | dentry->d_op == &autofs4_dentry_operations) && |
853 | dentry->d_fsdata != NULL; | |
854 | } | |
855 | ||
856 | /* | |
857 | * ioctl()'s on the root directory is the chief method for the daemon to | |
858 | * generate kernel reactions | |
859 | */ | |
3663df70 FW |
860 | static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp, |
861 | unsigned int cmd, unsigned long arg) | |
1da177e4 LT |
862 | { |
863 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
864 | void __user *p = (void __user *)arg; | |
865 | ||
866 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 867 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 868 | |
d78e53c8 SB |
869 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
870 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
871 | return -ENOTTY; |
872 | ||
d78e53c8 | 873 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
874 | return -EPERM; |
875 | ||
876 | switch(cmd) { | |
877 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
878 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
879 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
880 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
881 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
882 | autofs4_catatonic_mode(sbi); | |
883 | return 0; | |
884 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
885 | return autofs4_get_protover(sbi, p); | |
886 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
887 | return autofs4_get_protosubver(sbi, p); | |
888 | case AUTOFS_IOC_SETTIMEOUT: | |
889 | return autofs4_get_set_timeout(sbi, p); | |
c9243f5b AB |
890 | #ifdef CONFIG_COMPAT |
891 | case AUTOFS_IOC_SETTIMEOUT32: | |
892 | return autofs4_compat_get_set_timeout(sbi, p); | |
893 | #endif | |
1da177e4 | 894 | |
1da177e4 | 895 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 896 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
897 | |
898 | /* return a single thing to expire */ | |
899 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 900 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
901 | /* same as above, but can send multiple expires through pipe */ |
902 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 903 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
904 | |
905 | default: | |
906 | return -ENOSYS; | |
907 | } | |
908 | } | |
3663df70 FW |
909 | |
910 | static long autofs4_root_ioctl(struct file *filp, | |
911 | unsigned int cmd, unsigned long arg) | |
912 | { | |
3663df70 | 913 | struct inode *inode = filp->f_dentry->d_inode; |
de47de74 | 914 | return autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); |
3663df70 | 915 | } |
c9243f5b AB |
916 | |
917 | #ifdef CONFIG_COMPAT | |
918 | static long autofs4_root_compat_ioctl(struct file *filp, | |
919 | unsigned int cmd, unsigned long arg) | |
920 | { | |
921 | struct inode *inode = filp->f_path.dentry->d_inode; | |
922 | int ret; | |
923 | ||
c9243f5b AB |
924 | if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL) |
925 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg); | |
926 | else | |
927 | ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, | |
928 | (unsigned long)compat_ptr(arg)); | |
c9243f5b AB |
929 | |
930 | return ret; | |
931 | } | |
932 | #endif |