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 | ||
1da177e4 LT |
107 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
108 | { | |
a4669ed8 | 109 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 110 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 111 | |
1da177e4 LT |
112 | DPRINTK("file=%p dentry=%p %.*s", |
113 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
114 | ||
115 | if (autofs4_oz_mode(sbi)) | |
116 | goto out; | |
117 | ||
ff9cd499 IK |
118 | /* |
119 | * An empty directory in an autofs file system is always a | |
120 | * mount point. The daemon must have failed to mount this | |
121 | * during lookup so it doesn't exist. This can happen, for | |
122 | * example, if user space returns an incorrect status for a | |
123 | * mount request. Otherwise we're doing a readdir on the | |
124 | * autofs file system so just let the libfs routines handle | |
125 | * it. | |
126 | */ | |
127 | spin_lock(&dcache_lock); | |
128 | if (!d_mountpoint(dentry) && __simple_empty(dentry)) { | |
1da177e4 | 129 | spin_unlock(&dcache_lock); |
ff9cd499 | 130 | return -ENOENT; |
1da177e4 | 131 | } |
ff9cd499 | 132 | spin_unlock(&dcache_lock); |
1da177e4 | 133 | |
1da177e4 | 134 | out: |
ff9cd499 | 135 | return dcache_dir_open(inode, file); |
1da177e4 LT |
136 | } |
137 | ||
862b110f | 138 | static int try_to_fill_dentry(struct dentry *dentry, int flags) |
1da177e4 | 139 | { |
862b110f | 140 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
718c604a | 141 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
9d2de6ad | 142 | int status; |
1da177e4 | 143 | |
1da177e4 LT |
144 | DPRINTK("dentry=%p %.*s ino=%p", |
145 | dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); | |
146 | ||
718c604a IK |
147 | /* |
148 | * Wait for a pending mount, triggering one if there | |
149 | * isn't one already | |
150 | */ | |
1da177e4 LT |
151 | if (dentry->d_inode == NULL) { |
152 | DPRINTK("waiting for mount name=%.*s", | |
153 | dentry->d_name.len, dentry->d_name.name); | |
154 | ||
155 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
718c604a | 156 | |
1da177e4 LT |
157 | DPRINTK("mount done status=%d", status); |
158 | ||
1da177e4 LT |
159 | /* Turn this into a real negative dentry? */ |
160 | if (status == -ENOENT) { | |
1da177e4 LT |
161 | spin_lock(&dentry->d_lock); |
162 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
163 | spin_unlock(&dentry->d_lock); | |
34ca959c | 164 | return status; |
1da177e4 LT |
165 | } else if (status) { |
166 | /* Return a negative dentry, but leave it "pending" */ | |
34ca959c | 167 | return status; |
1da177e4 LT |
168 | } |
169 | /* Trigger mount for path component or follow link */ | |
26e81b31 IK |
170 | } else if (dentry->d_flags & DCACHE_AUTOFS_PENDING || |
171 | flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) || | |
1da177e4 LT |
172 | current->link_count) { |
173 | DPRINTK("waiting for mount name=%.*s", | |
174 | dentry->d_name.len, dentry->d_name.name); | |
175 | ||
176 | spin_lock(&dentry->d_lock); | |
177 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
178 | spin_unlock(&dentry->d_lock); | |
179 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
180 | ||
181 | DPRINTK("mount done status=%d", status); | |
182 | ||
183 | if (status) { | |
184 | spin_lock(&dentry->d_lock); | |
185 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
186 | spin_unlock(&dentry->d_lock); | |
34ca959c | 187 | return status; |
1da177e4 LT |
188 | } |
189 | } | |
190 | ||
e0a7aae9 IK |
191 | /* Initialize expiry counter after successful mount */ |
192 | if (ino) | |
193 | ino->last_used = jiffies; | |
194 | ||
1da177e4 LT |
195 | spin_lock(&dentry->d_lock); |
196 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
197 | spin_unlock(&dentry->d_lock); | |
03379044 | 198 | |
9d2de6ad | 199 | return 0; |
34ca959c IK |
200 | } |
201 | ||
202 | /* For autofs direct mounts the follow link triggers the mount */ | |
203 | static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) | |
204 | { | |
205 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
a5370553 | 206 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
34ca959c IK |
207 | int oz_mode = autofs4_oz_mode(sbi); |
208 | unsigned int lookup_type; | |
209 | int status; | |
210 | ||
211 | DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d", | |
212 | dentry, dentry->d_name.len, dentry->d_name.name, oz_mode, | |
213 | nd->flags); | |
6e60a9ab IK |
214 | /* |
215 | * For an expire of a covered direct or offset mount we need | |
9393bd07 | 216 | * to break out of follow_down() at the autofs mount trigger |
6e60a9ab IK |
217 | * (d_mounted--), so we can see the expiring flag, and manage |
218 | * the blocking and following here until the expire is completed. | |
219 | */ | |
220 | if (oz_mode) { | |
221 | spin_lock(&sbi->fs_lock); | |
222 | if (ino->flags & AUTOFS_INF_EXPIRING) { | |
223 | spin_unlock(&sbi->fs_lock); | |
224 | /* Follow down to our covering mount. */ | |
9393bd07 | 225 | if (!follow_down(&nd->path)) |
6e60a9ab | 226 | goto done; |
ec6e8c7d | 227 | goto follow; |
6e60a9ab IK |
228 | } |
229 | spin_unlock(&sbi->fs_lock); | |
34ca959c | 230 | goto done; |
6e60a9ab | 231 | } |
34ca959c | 232 | |
6e60a9ab | 233 | /* If an expire request is pending everyone must wait. */ |
06a35985 | 234 | autofs4_expire_wait(dentry); |
871f9434 | 235 | |
6e60a9ab IK |
236 | /* We trigger a mount for almost all flags */ |
237 | lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS); | |
238 | if (!(lookup_type || dentry->d_flags & DCACHE_AUTOFS_PENDING)) | |
ec6e8c7d | 239 | goto follow; |
6e60a9ab | 240 | |
871f9434 | 241 | /* |
6e60a9ab IK |
242 | * If the dentry contains directories then it is an autofs |
243 | * multi-mount with no root mount offset. So don't try to | |
244 | * mount it again. | |
871f9434 IK |
245 | */ |
246 | spin_lock(&dcache_lock); | |
26e81b31 IK |
247 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING || |
248 | (!d_mountpoint(dentry) && __simple_empty(dentry))) { | |
871f9434 IK |
249 | spin_unlock(&dcache_lock); |
250 | ||
251 | status = try_to_fill_dentry(dentry, 0); | |
252 | if (status) | |
253 | goto out_error; | |
254 | ||
6e60a9ab | 255 | goto follow; |
34ca959c | 256 | } |
871f9434 | 257 | spin_unlock(&dcache_lock); |
6e60a9ab IK |
258 | follow: |
259 | /* | |
260 | * If there is no root mount it must be an autofs | |
261 | * multi-mount with no root offset so we don't need | |
262 | * to follow it. | |
263 | */ | |
264 | if (d_mountpoint(dentry)) { | |
9393bd07 | 265 | if (!autofs4_follow_mount(&nd->path)) { |
6e60a9ab IK |
266 | status = -ENOENT; |
267 | goto out_error; | |
268 | } | |
269 | } | |
34ca959c IK |
270 | |
271 | done: | |
272 | return NULL; | |
273 | ||
274 | out_error: | |
1d957f9b | 275 | path_put(&nd->path); |
34ca959c | 276 | return ERR_PTR(status); |
1da177e4 LT |
277 | } |
278 | ||
279 | /* | |
280 | * Revalidate is called on every cache lookup. Some of those | |
281 | * cache lookups may actually happen while the dentry is not | |
282 | * yet completely filled in, and revalidate has to delay such | |
283 | * lookups.. | |
284 | */ | |
718c604a | 285 | static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 286 | { |
718c604a | 287 | struct inode *dir = dentry->d_parent->d_inode; |
1da177e4 LT |
288 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
289 | int oz_mode = autofs4_oz_mode(sbi); | |
290 | int flags = nd ? nd->flags : 0; | |
bcdc5e01 | 291 | int status = 1; |
1da177e4 LT |
292 | |
293 | /* Pending dentry */ | |
97e7449a | 294 | spin_lock(&sbi->fs_lock); |
1da177e4 | 295 | if (autofs4_ispending(dentry)) { |
bcdc5e01 | 296 | /* The daemon never causes a mount to trigger */ |
97e7449a IK |
297 | spin_unlock(&sbi->fs_lock); |
298 | ||
bcdc5e01 IK |
299 | if (oz_mode) |
300 | return 1; | |
301 | ||
06a35985 IK |
302 | /* |
303 | * If the directory has gone away due to an expire | |
304 | * we have been called as ->d_revalidate() and so | |
305 | * we need to return false and proceed to ->lookup(). | |
306 | */ | |
307 | if (autofs4_expire_wait(dentry) == -EAGAIN) | |
308 | return 0; | |
309 | ||
bcdc5e01 IK |
310 | /* |
311 | * A zero status is success otherwise we have a | |
312 | * negative error code. | |
313 | */ | |
314 | status = try_to_fill_dentry(dentry, flags); | |
315 | if (status == 0) | |
f50b6f86 IK |
316 | return 1; |
317 | ||
bcdc5e01 | 318 | return status; |
1da177e4 | 319 | } |
97e7449a | 320 | spin_unlock(&sbi->fs_lock); |
1da177e4 LT |
321 | |
322 | /* Negative dentry.. invalidate if "old" */ | |
323 | if (dentry->d_inode == NULL) | |
2d753e62 | 324 | return 0; |
1da177e4 LT |
325 | |
326 | /* Check for a non-mountpoint directory with no contents */ | |
327 | spin_lock(&dcache_lock); | |
328 | if (S_ISDIR(dentry->d_inode->i_mode) && | |
329 | !d_mountpoint(dentry) && | |
90a59c7c | 330 | __simple_empty(dentry)) { |
1da177e4 LT |
331 | DPRINTK("dentry=%p %.*s, emptydir", |
332 | dentry, dentry->d_name.len, dentry->d_name.name); | |
333 | spin_unlock(&dcache_lock); | |
97e7449a | 334 | |
bcdc5e01 IK |
335 | /* The daemon never causes a mount to trigger */ |
336 | if (oz_mode) | |
337 | return 1; | |
338 | ||
339 | /* | |
340 | * A zero status is success otherwise we have a | |
341 | * negative error code. | |
342 | */ | |
343 | status = try_to_fill_dentry(dentry, flags); | |
344 | if (status == 0) | |
345 | return 1; | |
346 | ||
347 | return status; | |
1da177e4 LT |
348 | } |
349 | spin_unlock(&dcache_lock); | |
350 | ||
1da177e4 LT |
351 | return 1; |
352 | } | |
353 | ||
34ca959c | 354 | void autofs4_dentry_release(struct dentry *de) |
1da177e4 LT |
355 | { |
356 | struct autofs_info *inf; | |
357 | ||
358 | DPRINTK("releasing %p", de); | |
359 | ||
360 | inf = autofs4_dentry_ino(de); | |
361 | de->d_fsdata = NULL; | |
362 | ||
363 | if (inf) { | |
f50b6f86 IK |
364 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); |
365 | ||
f50b6f86 | 366 | if (sbi) { |
5f6f4f28 | 367 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
368 | if (!list_empty(&inf->active)) |
369 | list_del(&inf->active); | |
5f6f4f28 IK |
370 | if (!list_empty(&inf->expiring)) |
371 | list_del(&inf->expiring); | |
372 | spin_unlock(&sbi->lookup_lock); | |
f50b6f86 IK |
373 | } |
374 | ||
c3724b12 JM |
375 | inf->dentry = NULL; |
376 | inf->inode = NULL; | |
377 | ||
1da177e4 LT |
378 | autofs4_free_ino(inf); |
379 | } | |
380 | } | |
381 | ||
382 | /* For dentries of directories in the root dir */ | |
08f11513 | 383 | static const struct dentry_operations autofs4_root_dentry_operations = { |
1da177e4 LT |
384 | .d_revalidate = autofs4_revalidate, |
385 | .d_release = autofs4_dentry_release, | |
386 | }; | |
387 | ||
388 | /* For other dentries */ | |
08f11513 | 389 | static const struct dentry_operations autofs4_dentry_operations = { |
1da177e4 LT |
390 | .d_revalidate = autofs4_revalidate, |
391 | .d_release = autofs4_dentry_release, | |
392 | }; | |
393 | ||
25767378 IK |
394 | static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name) |
395 | { | |
396 | unsigned int len = name->len; | |
397 | unsigned int hash = name->hash; | |
398 | const unsigned char *str = name->name; | |
399 | struct list_head *p, *head; | |
400 | ||
401 | spin_lock(&dcache_lock); | |
402 | spin_lock(&sbi->lookup_lock); | |
403 | head = &sbi->active_list; | |
404 | list_for_each(p, head) { | |
405 | struct autofs_info *ino; | |
406 | struct dentry *dentry; | |
407 | struct qstr *qstr; | |
408 | ||
409 | ino = list_entry(p, struct autofs_info, active); | |
410 | dentry = ino->dentry; | |
411 | ||
412 | spin_lock(&dentry->d_lock); | |
413 | ||
414 | /* Already gone? */ | |
415 | if (atomic_read(&dentry->d_count) == 0) | |
416 | goto next; | |
417 | ||
418 | qstr = &dentry->d_name; | |
419 | ||
420 | if (dentry->d_name.hash != hash) | |
421 | goto next; | |
422 | if (dentry->d_parent != parent) | |
423 | goto next; | |
424 | ||
425 | if (qstr->len != len) | |
426 | goto next; | |
427 | if (memcmp(qstr->name, str, len)) | |
428 | goto next; | |
429 | ||
430 | if (d_unhashed(dentry)) { | |
431 | dget(dentry); | |
432 | spin_unlock(&dentry->d_lock); | |
433 | spin_unlock(&sbi->lookup_lock); | |
434 | spin_unlock(&dcache_lock); | |
435 | return dentry; | |
436 | } | |
437 | next: | |
438 | spin_unlock(&dentry->d_lock); | |
439 | } | |
440 | spin_unlock(&sbi->lookup_lock); | |
441 | spin_unlock(&dcache_lock); | |
442 | ||
443 | return NULL; | |
444 | } | |
445 | ||
5f6f4f28 | 446 | static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name) |
f50b6f86 IK |
447 | { |
448 | unsigned int len = name->len; | |
449 | unsigned int hash = name->hash; | |
450 | const unsigned char *str = name->name; | |
451 | struct list_head *p, *head; | |
452 | ||
453 | spin_lock(&dcache_lock); | |
5f6f4f28 IK |
454 | spin_lock(&sbi->lookup_lock); |
455 | head = &sbi->expiring_list; | |
f50b6f86 IK |
456 | list_for_each(p, head) { |
457 | struct autofs_info *ino; | |
458 | struct dentry *dentry; | |
459 | struct qstr *qstr; | |
460 | ||
5f6f4f28 | 461 | ino = list_entry(p, struct autofs_info, expiring); |
f50b6f86 IK |
462 | dentry = ino->dentry; |
463 | ||
464 | spin_lock(&dentry->d_lock); | |
465 | ||
466 | /* Bad luck, we've already been dentry_iput */ | |
467 | if (!dentry->d_inode) | |
468 | goto next; | |
469 | ||
470 | qstr = &dentry->d_name; | |
471 | ||
472 | if (dentry->d_name.hash != hash) | |
473 | goto next; | |
474 | if (dentry->d_parent != parent) | |
475 | goto next; | |
476 | ||
477 | if (qstr->len != len) | |
478 | goto next; | |
479 | if (memcmp(qstr->name, str, len)) | |
480 | goto next; | |
481 | ||
482 | if (d_unhashed(dentry)) { | |
f50b6f86 | 483 | dget(dentry); |
f50b6f86 | 484 | spin_unlock(&dentry->d_lock); |
5f6f4f28 | 485 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
486 | spin_unlock(&dcache_lock); |
487 | return dentry; | |
488 | } | |
489 | next: | |
490 | spin_unlock(&dentry->d_lock); | |
491 | } | |
5f6f4f28 | 492 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
493 | spin_unlock(&dcache_lock); |
494 | ||
495 | return NULL; | |
496 | } | |
497 | ||
1da177e4 LT |
498 | /* Lookups in the root directory */ |
499 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
500 | { | |
501 | struct autofs_sb_info *sbi; | |
25767378 IK |
502 | struct autofs_info *ino; |
503 | struct dentry *expiring, *unhashed; | |
1da177e4 LT |
504 | int oz_mode; |
505 | ||
506 | DPRINTK("name = %.*s", | |
507 | dentry->d_name.len, dentry->d_name.name); | |
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); | |
1da177e4 | 514 | oz_mode = autofs4_oz_mode(sbi); |
718c604a | 515 | |
1da177e4 | 516 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
a47afb0f | 517 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); |
1da177e4 | 518 | |
25767378 IK |
519 | unhashed = autofs4_lookup_active(sbi, dentry->d_parent, &dentry->d_name); |
520 | if (unhashed) | |
521 | dentry = unhashed; | |
522 | else { | |
523 | /* | |
524 | * Mark the dentry incomplete but don't hash it. We do this | |
525 | * to serialize our inode creation operations (symlink and | |
526 | * mkdir) which prevents deadlock during the callback to | |
527 | * the daemon. Subsequent user space lookups for the same | |
528 | * dentry are placed on the wait queue while the daemon | |
529 | * itself is allowed passage unresticted so the create | |
530 | * operation itself can then hash the dentry. Finally, | |
531 | * we check for the hashed dentry and return the newly | |
532 | * hashed dentry. | |
533 | */ | |
534 | dentry->d_op = &autofs4_root_dentry_operations; | |
535 | ||
536 | /* | |
537 | * And we need to ensure that the same dentry is used for | |
538 | * all following lookup calls until it is hashed so that | |
539 | * the dentry flags are persistent throughout the request. | |
540 | */ | |
541 | ino = autofs4_init_ino(NULL, sbi, 0555); | |
542 | if (!ino) | |
543 | return ERR_PTR(-ENOMEM); | |
544 | ||
545 | dentry->d_fsdata = ino; | |
546 | ino->dentry = dentry; | |
547 | ||
4f8427d1 | 548 | autofs4_add_active(dentry); |
5f6f4f28 | 549 | |
25767378 IK |
550 | d_instantiate(dentry, NULL); |
551 | } | |
5f6f4f28 | 552 | |
1da177e4 | 553 | if (!oz_mode) { |
8f63aaa8 IK |
554 | mutex_unlock(&dir->i_mutex); |
555 | expiring = autofs4_lookup_expiring(sbi, | |
556 | dentry->d_parent, | |
557 | &dentry->d_name); | |
558 | if (expiring) { | |
559 | /* | |
560 | * If we are racing with expire the request might not | |
561 | * be quite complete but the directory has been removed | |
562 | * so it must have been successful, so just wait for it. | |
563 | */ | |
564 | ino = autofs4_dentry_ino(expiring); | |
565 | autofs4_expire_wait(expiring); | |
566 | spin_lock(&sbi->lookup_lock); | |
567 | if (!list_empty(&ino->expiring)) | |
568 | list_del_init(&ino->expiring); | |
569 | spin_unlock(&sbi->lookup_lock); | |
570 | dput(expiring); | |
571 | } | |
572 | ||
1da177e4 LT |
573 | spin_lock(&dentry->d_lock); |
574 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
575 | spin_unlock(&dentry->d_lock); | |
8f63aaa8 | 576 | if (dentry->d_op && dentry->d_op->d_revalidate) |
c432c258 | 577 | (dentry->d_op->d_revalidate)(dentry, nd); |
8f63aaa8 | 578 | mutex_lock(&dir->i_mutex); |
1da177e4 LT |
579 | } |
580 | ||
581 | /* | |
582 | * If we are still pending, check if we had to handle | |
583 | * a signal. If so we can force a restart.. | |
584 | */ | |
585 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { | |
586 | /* See if we were interrupted */ | |
587 | if (signal_pending(current)) { | |
588 | sigset_t *sigset = ¤t->pending.signal; | |
589 | if (sigismember (sigset, SIGKILL) || | |
590 | sigismember (sigset, SIGQUIT) || | |
591 | sigismember (sigset, SIGINT)) { | |
25767378 IK |
592 | if (unhashed) |
593 | dput(unhashed); | |
1da177e4 LT |
594 | return ERR_PTR(-ERESTARTNOINTR); |
595 | } | |
596 | } | |
25767378 IK |
597 | if (!oz_mode) { |
598 | spin_lock(&dentry->d_lock); | |
599 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
600 | spin_unlock(&dentry->d_lock); | |
601 | } | |
1da177e4 LT |
602 | } |
603 | ||
604 | /* | |
605 | * If this dentry is unhashed, then we shouldn't honour this | |
c9ffec48 IK |
606 | * lookup. Returning ENOENT here doesn't do the right thing |
607 | * for all system calls, but it should be OK for the operations | |
608 | * we permit from an autofs. | |
1da177e4 | 609 | */ |
1864f7bd | 610 | if (!oz_mode && d_unhashed(dentry)) { |
c9ffec48 IK |
611 | /* |
612 | * A user space application can (and has done in the past) | |
613 | * remove and re-create this directory during the callback. | |
614 | * This can leave us with an unhashed dentry, but a | |
615 | * successful mount! So we need to perform another | |
616 | * cached lookup in case the dentry now exists. | |
617 | */ | |
618 | struct dentry *parent = dentry->d_parent; | |
619 | struct dentry *new = d_lookup(parent, &dentry->d_name); | |
620 | if (new != NULL) | |
621 | dentry = new; | |
622 | else | |
623 | dentry = ERR_PTR(-ENOENT); | |
624 | ||
25767378 IK |
625 | if (unhashed) |
626 | dput(unhashed); | |
627 | ||
c9ffec48 | 628 | return dentry; |
f50b6f86 IK |
629 | } |
630 | ||
25767378 IK |
631 | if (unhashed) |
632 | return unhashed; | |
633 | ||
1da177e4 LT |
634 | return NULL; |
635 | } | |
636 | ||
637 | static int autofs4_dir_symlink(struct inode *dir, | |
638 | struct dentry *dentry, | |
639 | const char *symname) | |
640 | { | |
641 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
642 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 643 | struct autofs_info *p_ino; |
1da177e4 LT |
644 | struct inode *inode; |
645 | char *cp; | |
646 | ||
647 | DPRINTK("%s <- %.*s", symname, | |
648 | dentry->d_name.len, dentry->d_name.name); | |
649 | ||
650 | if (!autofs4_oz_mode(sbi)) | |
651 | return -EACCES; | |
652 | ||
653 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
25767378 IK |
654 | if (!ino) |
655 | return -ENOMEM; | |
1da177e4 | 656 | |
4f8427d1 | 657 | autofs4_del_active(dentry); |
1da177e4 | 658 | |
ef581a74 | 659 | ino->size = strlen(symname); |
25767378 IK |
660 | cp = kmalloc(ino->size + 1, GFP_KERNEL); |
661 | if (!cp) { | |
662 | if (!dentry->d_fsdata) | |
663 | kfree(ino); | |
664 | return -ENOMEM; | |
1da177e4 LT |
665 | } |
666 | ||
667 | strcpy(cp, symname); | |
668 | ||
669 | inode = autofs4_get_inode(dir->i_sb, ino); | |
25767378 IK |
670 | if (!inode) { |
671 | kfree(cp); | |
672 | if (!dentry->d_fsdata) | |
673 | kfree(ino); | |
674 | return -ENOMEM; | |
675 | } | |
1864f7bd | 676 | d_add(dentry, inode); |
1da177e4 LT |
677 | |
678 | if (dir == dir->i_sb->s_root->d_inode) | |
679 | dentry->d_op = &autofs4_root_dentry_operations; | |
680 | else | |
681 | dentry->d_op = &autofs4_dentry_operations; | |
682 | ||
683 | dentry->d_fsdata = ino; | |
684 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
685 | atomic_inc(&ino->count); |
686 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
687 | if (p_ino && dentry->d_parent != dentry) | |
688 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
689 | ino->inode = inode; |
690 | ||
25767378 | 691 | ino->u.symlink = cp; |
1da177e4 LT |
692 | dir->i_mtime = CURRENT_TIME; |
693 | ||
694 | return 0; | |
695 | } | |
696 | ||
697 | /* | |
698 | * NOTE! | |
699 | * | |
700 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
701 | * that the file no longer exists. However, doing that means that the | |
702 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 703 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
704 | * We simply d_drop it and add it to a expiring list in the super block, |
705 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
706 | * |
707 | * If a process is blocked on the dentry waiting for the expire to finish, | |
708 | * it will invalidate the dentry and try to mount with a new one. | |
709 | * | |
710 | * Also see autofs4_dir_rmdir().. | |
711 | */ | |
712 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
713 | { | |
714 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
715 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 716 | struct autofs_info *p_ino; |
1da177e4 LT |
717 | |
718 | /* This allows root to remove symlinks */ | |
d78e53c8 | 719 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
720 | return -EACCES; |
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 LT |
727 | dput(ino->dentry); |
728 | ||
729 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 730 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
731 | |
732 | dir->i_mtime = CURRENT_TIME; | |
733 | ||
f50b6f86 | 734 | spin_lock(&dcache_lock); |
5f6f4f28 | 735 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
736 | if (list_empty(&ino->expiring)) |
737 | list_add(&ino->expiring, &sbi->expiring_list); | |
5f6f4f28 | 738 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
739 | spin_lock(&dentry->d_lock); |
740 | __d_drop(dentry); | |
741 | spin_unlock(&dentry->d_lock); | |
742 | spin_unlock(&dcache_lock); | |
1da177e4 LT |
743 | |
744 | return 0; | |
745 | } | |
746 | ||
747 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
748 | { | |
749 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
750 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 751 | struct autofs_info *p_ino; |
1da177e4 | 752 | |
f50b6f86 IK |
753 | DPRINTK("dentry %p, removing %.*s", |
754 | dentry, dentry->d_name.len, dentry->d_name.name); | |
755 | ||
1da177e4 LT |
756 | if (!autofs4_oz_mode(sbi)) |
757 | return -EACCES; | |
758 | ||
759 | spin_lock(&dcache_lock); | |
760 | if (!list_empty(&dentry->d_subdirs)) { | |
761 | spin_unlock(&dcache_lock); | |
762 | return -ENOTEMPTY; | |
763 | } | |
5f6f4f28 | 764 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
765 | if (list_empty(&ino->expiring)) |
766 | list_add(&ino->expiring, &sbi->expiring_list); | |
5f6f4f28 | 767 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
768 | spin_lock(&dentry->d_lock); |
769 | __d_drop(dentry); | |
770 | spin_unlock(&dentry->d_lock); | |
771 | spin_unlock(&dcache_lock); | |
772 | ||
1aff3c8b IK |
773 | if (atomic_dec_and_test(&ino->count)) { |
774 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
775 | if (p_ino && dentry->d_parent != dentry) | |
776 | atomic_dec(&p_ino->count); | |
777 | } | |
1da177e4 | 778 | dput(ino->dentry); |
1da177e4 | 779 | dentry->d_inode->i_size = 0; |
ce71ec36 | 780 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
781 | |
782 | if (dir->i_nlink) | |
9a53c3a7 | 783 | drop_nlink(dir); |
1da177e4 LT |
784 | |
785 | return 0; | |
786 | } | |
787 | ||
788 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
789 | { | |
790 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
791 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 792 | struct autofs_info *p_ino; |
1da177e4 LT |
793 | struct inode *inode; |
794 | ||
d78e53c8 | 795 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
796 | return -EACCES; |
797 | ||
798 | DPRINTK("dentry %p, creating %.*s", | |
799 | dentry, dentry->d_name.len, dentry->d_name.name); | |
800 | ||
801 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
25767378 IK |
802 | if (!ino) |
803 | return -ENOMEM; | |
804 | ||
4f8427d1 | 805 | autofs4_del_active(dentry); |
1da177e4 LT |
806 | |
807 | inode = autofs4_get_inode(dir->i_sb, ino); | |
25767378 IK |
808 | if (!inode) { |
809 | if (!dentry->d_fsdata) | |
810 | kfree(ino); | |
811 | return -ENOMEM; | |
812 | } | |
1864f7bd | 813 | d_add(dentry, inode); |
1da177e4 LT |
814 | |
815 | if (dir == dir->i_sb->s_root->d_inode) | |
816 | dentry->d_op = &autofs4_root_dentry_operations; | |
817 | else | |
818 | dentry->d_op = &autofs4_dentry_operations; | |
819 | ||
820 | dentry->d_fsdata = ino; | |
821 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
822 | atomic_inc(&ino->count); |
823 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
824 | if (p_ino && dentry->d_parent != dentry) | |
825 | atomic_inc(&p_ino->count); | |
1da177e4 | 826 | ino->inode = inode; |
d8c76e6f | 827 | inc_nlink(dir); |
1da177e4 LT |
828 | dir->i_mtime = CURRENT_TIME; |
829 | ||
830 | return 0; | |
831 | } | |
832 | ||
833 | /* Get/set timeout ioctl() operation */ | |
834 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, | |
835 | unsigned long __user *p) | |
836 | { | |
837 | int rv; | |
838 | unsigned long ntimeout; | |
839 | ||
d78e53c8 SB |
840 | if ((rv = get_user(ntimeout, p)) || |
841 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
842 | return rv; |
843 | ||
d78e53c8 | 844 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
845 | sbi->exp_timeout = 0; |
846 | else | |
847 | sbi->exp_timeout = ntimeout * HZ; | |
848 | ||
849 | return 0; | |
850 | } | |
851 | ||
852 | /* Return protocol version */ | |
853 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
854 | { | |
855 | return put_user(sbi->version, p); | |
856 | } | |
857 | ||
858 | /* Return protocol sub version */ | |
859 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
860 | { | |
861 | return put_user(sbi->sub_version, p); | |
862 | } | |
863 | ||
1da177e4 LT |
864 | /* |
865 | * Tells the daemon whether it can umount the autofs mount. | |
866 | */ | |
867 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
868 | { | |
869 | int status = 0; | |
870 | ||
e3474a8e | 871 | if (may_umount(mnt)) |
1da177e4 LT |
872 | status = 1; |
873 | ||
874 | DPRINTK("returning %d", status); | |
875 | ||
876 | status = put_user(status, p); | |
877 | ||
878 | return status; | |
879 | } | |
880 | ||
881 | /* Identify autofs4_dentries - this is so we can tell if there's | |
882 | an extra dentry refcount or not. We only hold a refcount on the | |
883 | dentry if its non-negative (ie, d_inode != NULL) | |
884 | */ | |
885 | int is_autofs4_dentry(struct dentry *dentry) | |
886 | { | |
887 | return dentry && dentry->d_inode && | |
888 | (dentry->d_op == &autofs4_root_dentry_operations || | |
889 | dentry->d_op == &autofs4_dentry_operations) && | |
890 | dentry->d_fsdata != NULL; | |
891 | } | |
892 | ||
893 | /* | |
894 | * ioctl()'s on the root directory is the chief method for the daemon to | |
895 | * generate kernel reactions | |
896 | */ | |
897 | static int autofs4_root_ioctl(struct inode *inode, struct file *filp, | |
898 | unsigned int cmd, unsigned long arg) | |
899 | { | |
900 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
901 | void __user *p = (void __user *)arg; | |
902 | ||
903 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 904 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 905 | |
d78e53c8 SB |
906 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
907 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
908 | return -ENOTTY; |
909 | ||
d78e53c8 | 910 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
911 | return -EPERM; |
912 | ||
913 | switch(cmd) { | |
914 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
915 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
916 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
917 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
918 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
919 | autofs4_catatonic_mode(sbi); | |
920 | return 0; | |
921 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
922 | return autofs4_get_protover(sbi, p); | |
923 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
924 | return autofs4_get_protosubver(sbi, p); | |
925 | case AUTOFS_IOC_SETTIMEOUT: | |
926 | return autofs4_get_set_timeout(sbi, p); | |
927 | ||
1da177e4 | 928 | case AUTOFS_IOC_ASKUMOUNT: |
a4669ed8 | 929 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
930 | |
931 | /* return a single thing to expire */ | |
932 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 933 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
934 | /* same as above, but can send multiple expires through pipe */ |
935 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 936 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
937 | |
938 | default: | |
939 | return -ENOSYS; | |
940 | } | |
941 | } |