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 LT |
28 | static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir); |
29 | static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); | |
34ca959c | 30 | static void *autofs4_follow_link(struct dentry *, struct nameidata *); |
1da177e4 | 31 | |
6d5cb926 IK |
32 | #define TRIGGER_FLAGS (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) |
33 | #define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE) | |
34 | ||
4b6f5d20 | 35 | const struct file_operations autofs4_root_operations = { |
1da177e4 LT |
36 | .open = dcache_dir_open, |
37 | .release = dcache_dir_close, | |
38 | .read = generic_read_dir, | |
39 | .readdir = autofs4_root_readdir, | |
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, |
1da177e4 LT |
48 | }; |
49 | ||
754661f1 | 50 | const struct inode_operations autofs4_indirect_root_inode_operations = { |
1da177e4 LT |
51 | .lookup = autofs4_lookup, |
52 | .unlink = autofs4_dir_unlink, | |
53 | .symlink = autofs4_dir_symlink, | |
54 | .mkdir = autofs4_dir_mkdir, | |
55 | .rmdir = autofs4_dir_rmdir, | |
56 | }; | |
57 | ||
754661f1 | 58 | const struct inode_operations autofs4_direct_root_inode_operations = { |
34ca959c | 59 | .lookup = autofs4_lookup, |
871f9434 IK |
60 | .unlink = autofs4_dir_unlink, |
61 | .mkdir = autofs4_dir_mkdir, | |
62 | .rmdir = autofs4_dir_rmdir, | |
34ca959c IK |
63 | .follow_link = autofs4_follow_link, |
64 | }; | |
65 | ||
754661f1 | 66 | const struct inode_operations autofs4_dir_inode_operations = { |
1da177e4 LT |
67 | .lookup = autofs4_lookup, |
68 | .unlink = autofs4_dir_unlink, | |
69 | .symlink = autofs4_dir_symlink, | |
70 | .mkdir = autofs4_dir_mkdir, | |
71 | .rmdir = autofs4_dir_rmdir, | |
72 | }; | |
73 | ||
74 | static int autofs4_root_readdir(struct file *file, void *dirent, | |
75 | filldir_t filldir) | |
76 | { | |
a4669ed8 | 77 | struct autofs_sb_info *sbi = autofs4_sbi(file->f_path.dentry->d_sb); |
1da177e4 LT |
78 | int oz_mode = autofs4_oz_mode(sbi); |
79 | ||
80 | DPRINTK("called, filp->f_pos = %lld", file->f_pos); | |
81 | ||
82 | /* | |
83 | * Don't set reghost flag if: | |
84 | * 1) f_pos is larger than zero -- we've already been here. | |
85 | * 2) we haven't even enabled reghosting in the 1st place. | |
86 | * 3) this is the daemon doing a readdir | |
87 | */ | |
88 | if (oz_mode && file->f_pos == 0 && sbi->reghost_enabled) | |
89 | sbi->needs_reghost = 1; | |
90 | ||
91 | DPRINTK("needs_reghost = %d", sbi->needs_reghost); | |
92 | ||
f360ce3b | 93 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
94 | } |
95 | ||
1da177e4 LT |
96 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
97 | { | |
a4669ed8 | 98 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 99 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 100 | |
1da177e4 LT |
101 | DPRINTK("file=%p dentry=%p %.*s", |
102 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
103 | ||
104 | if (autofs4_oz_mode(sbi)) | |
105 | goto out; | |
106 | ||
ff9cd499 IK |
107 | /* |
108 | * An empty directory in an autofs file system is always a | |
109 | * mount point. The daemon must have failed to mount this | |
110 | * during lookup so it doesn't exist. This can happen, for | |
111 | * example, if user space returns an incorrect status for a | |
112 | * mount request. Otherwise we're doing a readdir on the | |
113 | * autofs file system so just let the libfs routines handle | |
114 | * it. | |
115 | */ | |
116 | spin_lock(&dcache_lock); | |
117 | if (!d_mountpoint(dentry) && __simple_empty(dentry)) { | |
1da177e4 | 118 | spin_unlock(&dcache_lock); |
ff9cd499 | 119 | return -ENOENT; |
1da177e4 | 120 | } |
ff9cd499 | 121 | spin_unlock(&dcache_lock); |
1da177e4 | 122 | |
1da177e4 | 123 | out: |
ff9cd499 | 124 | return dcache_dir_open(inode, file); |
1da177e4 LT |
125 | } |
126 | ||
862b110f | 127 | static int try_to_fill_dentry(struct dentry *dentry, int flags) |
1da177e4 | 128 | { |
862b110f | 129 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
718c604a | 130 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
9d2de6ad | 131 | int status; |
1da177e4 LT |
132 | |
133 | /* Block on any pending expiry here; invalidate the dentry | |
134 | when expiration is done to trigger mount request with a new | |
135 | dentry */ | |
718c604a | 136 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { |
1da177e4 LT |
137 | DPRINTK("waiting for expire %p name=%.*s", |
138 | dentry, dentry->d_name.len, dentry->d_name.name); | |
139 | ||
140 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
718c604a | 141 | |
1da177e4 | 142 | DPRINTK("expire done status=%d", status); |
718c604a | 143 | |
1684b2bb IK |
144 | /* |
145 | * If the directory still exists the mount request must | |
146 | * continue otherwise it can't be followed at the right | |
147 | * time during the walk. | |
148 | */ | |
149 | status = d_invalidate(dentry); | |
150 | if (status != -EBUSY) | |
f50b6f86 | 151 | return -EAGAIN; |
1da177e4 LT |
152 | } |
153 | ||
154 | DPRINTK("dentry=%p %.*s ino=%p", | |
155 | dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); | |
156 | ||
718c604a IK |
157 | /* |
158 | * Wait for a pending mount, triggering one if there | |
159 | * isn't one already | |
160 | */ | |
1da177e4 LT |
161 | if (dentry->d_inode == NULL) { |
162 | DPRINTK("waiting for mount name=%.*s", | |
163 | dentry->d_name.len, dentry->d_name.name); | |
164 | ||
165 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
718c604a | 166 | |
1da177e4 LT |
167 | DPRINTK("mount done status=%d", status); |
168 | ||
1da177e4 LT |
169 | /* Turn this into a real negative dentry? */ |
170 | if (status == -ENOENT) { | |
1da177e4 LT |
171 | spin_lock(&dentry->d_lock); |
172 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
173 | spin_unlock(&dentry->d_lock); | |
34ca959c | 174 | return status; |
1da177e4 LT |
175 | } else if (status) { |
176 | /* Return a negative dentry, but leave it "pending" */ | |
34ca959c | 177 | return status; |
1da177e4 LT |
178 | } |
179 | /* Trigger mount for path component or follow link */ | |
26e81b31 IK |
180 | } else if (dentry->d_flags & DCACHE_AUTOFS_PENDING || |
181 | flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) || | |
1da177e4 LT |
182 | current->link_count) { |
183 | DPRINTK("waiting for mount name=%.*s", | |
184 | dentry->d_name.len, dentry->d_name.name); | |
185 | ||
186 | spin_lock(&dentry->d_lock); | |
187 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
188 | spin_unlock(&dentry->d_lock); | |
189 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
190 | ||
191 | DPRINTK("mount done status=%d", status); | |
192 | ||
193 | if (status) { | |
194 | spin_lock(&dentry->d_lock); | |
195 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
196 | spin_unlock(&dentry->d_lock); | |
34ca959c | 197 | return status; |
1da177e4 LT |
198 | } |
199 | } | |
200 | ||
e0a7aae9 IK |
201 | /* Initialize expiry counter after successful mount */ |
202 | if (ino) | |
203 | ino->last_used = jiffies; | |
204 | ||
1da177e4 LT |
205 | spin_lock(&dentry->d_lock); |
206 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
207 | spin_unlock(&dentry->d_lock); | |
03379044 | 208 | |
9d2de6ad | 209 | return 0; |
34ca959c IK |
210 | } |
211 | ||
212 | /* For autofs direct mounts the follow link triggers the mount */ | |
213 | static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) | |
214 | { | |
215 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
a5370553 | 216 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
34ca959c IK |
217 | int oz_mode = autofs4_oz_mode(sbi); |
218 | unsigned int lookup_type; | |
219 | int status; | |
220 | ||
221 | DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d", | |
222 | dentry, dentry->d_name.len, dentry->d_name.name, oz_mode, | |
223 | nd->flags); | |
224 | ||
225 | /* If it's our master or we shouldn't trigger a mount we're done */ | |
6d5cb926 | 226 | lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS); |
26e81b31 IK |
227 | if (oz_mode || |
228 | !(lookup_type || dentry->d_flags & DCACHE_AUTOFS_PENDING)) | |
34ca959c IK |
229 | goto done; |
230 | ||
a5370553 IK |
231 | /* If an expire request is pending wait for it. */ |
232 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { | |
871f9434 IK |
233 | DPRINTK("waiting for active request %p name=%.*s", |
234 | dentry, dentry->d_name.len, dentry->d_name.name); | |
235 | ||
236 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
237 | ||
238 | DPRINTK("request done status=%d", status); | |
239 | } | |
34ca959c | 240 | |
871f9434 IK |
241 | /* |
242 | * If the dentry contains directories then it is an | |
243 | * autofs multi-mount with no root mount offset. So | |
244 | * don't try to mount it again. | |
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 | ||
255 | /* | |
256 | * The mount succeeded but if there is no root mount | |
257 | * it must be an autofs multi-mount with no root offset | |
258 | * so we don't need to follow the mount. | |
259 | */ | |
260 | if (d_mountpoint(dentry)) { | |
4ac91378 JB |
261 | if (!autofs4_follow_mount(&nd->path.mnt, |
262 | &nd->path.dentry)) { | |
871f9434 IK |
263 | status = -ENOENT; |
264 | goto out_error; | |
265 | } | |
266 | } | |
267 | ||
268 | goto done; | |
34ca959c | 269 | } |
871f9434 | 270 | spin_unlock(&dcache_lock); |
34ca959c IK |
271 | |
272 | done: | |
273 | return NULL; | |
274 | ||
275 | out_error: | |
1d957f9b | 276 | path_put(&nd->path); |
34ca959c | 277 | return ERR_PTR(status); |
1da177e4 LT |
278 | } |
279 | ||
280 | /* | |
281 | * Revalidate is called on every cache lookup. Some of those | |
282 | * cache lookups may actually happen while the dentry is not | |
283 | * yet completely filled in, and revalidate has to delay such | |
284 | * lookups.. | |
285 | */ | |
718c604a | 286 | static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 287 | { |
718c604a | 288 | struct inode *dir = dentry->d_parent->d_inode; |
1da177e4 LT |
289 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
290 | int oz_mode = autofs4_oz_mode(sbi); | |
291 | int flags = nd ? nd->flags : 0; | |
bcdc5e01 | 292 | int status = 1; |
1da177e4 LT |
293 | |
294 | /* Pending dentry */ | |
295 | if (autofs4_ispending(dentry)) { | |
bcdc5e01 IK |
296 | /* The daemon never causes a mount to trigger */ |
297 | if (oz_mode) | |
298 | return 1; | |
299 | ||
300 | /* | |
301 | * A zero status is success otherwise we have a | |
302 | * negative error code. | |
303 | */ | |
304 | status = try_to_fill_dentry(dentry, flags); | |
305 | if (status == 0) | |
f50b6f86 IK |
306 | return 1; |
307 | ||
308 | /* | |
309 | * A status of EAGAIN here means that the dentry has gone | |
310 | * away while waiting for an expire to complete. If we are | |
311 | * racing with expire lookup will wait for it so this must | |
312 | * be a revalidate and we need to send it to lookup. | |
313 | */ | |
314 | if (status == -EAGAIN) | |
315 | return 0; | |
bcdc5e01 IK |
316 | |
317 | return status; | |
1da177e4 LT |
318 | } |
319 | ||
320 | /* Negative dentry.. invalidate if "old" */ | |
321 | if (dentry->d_inode == NULL) | |
2d753e62 | 322 | return 0; |
1da177e4 LT |
323 | |
324 | /* Check for a non-mountpoint directory with no contents */ | |
325 | spin_lock(&dcache_lock); | |
326 | if (S_ISDIR(dentry->d_inode->i_mode) && | |
327 | !d_mountpoint(dentry) && | |
90a59c7c | 328 | __simple_empty(dentry)) { |
1da177e4 LT |
329 | DPRINTK("dentry=%p %.*s, emptydir", |
330 | dentry, dentry->d_name.len, dentry->d_name.name); | |
331 | spin_unlock(&dcache_lock); | |
bcdc5e01 IK |
332 | /* The daemon never causes a mount to trigger */ |
333 | if (oz_mode) | |
334 | return 1; | |
335 | ||
336 | /* | |
337 | * A zero status is success otherwise we have a | |
338 | * negative error code. | |
339 | */ | |
340 | status = try_to_fill_dentry(dentry, flags); | |
341 | if (status == 0) | |
342 | return 1; | |
343 | ||
344 | return status; | |
1da177e4 LT |
345 | } |
346 | spin_unlock(&dcache_lock); | |
347 | ||
1da177e4 LT |
348 | return 1; |
349 | } | |
350 | ||
34ca959c | 351 | void autofs4_dentry_release(struct dentry *de) |
1da177e4 LT |
352 | { |
353 | struct autofs_info *inf; | |
354 | ||
355 | DPRINTK("releasing %p", de); | |
356 | ||
357 | inf = autofs4_dentry_ino(de); | |
358 | de->d_fsdata = NULL; | |
359 | ||
360 | if (inf) { | |
f50b6f86 IK |
361 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); |
362 | ||
f50b6f86 | 363 | if (sbi) { |
5f6f4f28 | 364 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
365 | if (!list_empty(&inf->active)) |
366 | list_del(&inf->active); | |
5f6f4f28 IK |
367 | if (!list_empty(&inf->expiring)) |
368 | list_del(&inf->expiring); | |
369 | spin_unlock(&sbi->lookup_lock); | |
f50b6f86 IK |
370 | } |
371 | ||
c3724b12 JM |
372 | inf->dentry = NULL; |
373 | inf->inode = NULL; | |
374 | ||
1da177e4 LT |
375 | autofs4_free_ino(inf); |
376 | } | |
377 | } | |
378 | ||
379 | /* For dentries of directories in the root dir */ | |
380 | static struct dentry_operations autofs4_root_dentry_operations = { | |
381 | .d_revalidate = autofs4_revalidate, | |
382 | .d_release = autofs4_dentry_release, | |
383 | }; | |
384 | ||
385 | /* For other dentries */ | |
386 | static struct dentry_operations autofs4_dentry_operations = { | |
387 | .d_revalidate = autofs4_revalidate, | |
388 | .d_release = autofs4_dentry_release, | |
389 | }; | |
390 | ||
25767378 IK |
391 | static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name) |
392 | { | |
393 | unsigned int len = name->len; | |
394 | unsigned int hash = name->hash; | |
395 | const unsigned char *str = name->name; | |
396 | struct list_head *p, *head; | |
397 | ||
398 | spin_lock(&dcache_lock); | |
399 | spin_lock(&sbi->lookup_lock); | |
400 | head = &sbi->active_list; | |
401 | list_for_each(p, head) { | |
402 | struct autofs_info *ino; | |
403 | struct dentry *dentry; | |
404 | struct qstr *qstr; | |
405 | ||
406 | ino = list_entry(p, struct autofs_info, active); | |
407 | dentry = ino->dentry; | |
408 | ||
409 | spin_lock(&dentry->d_lock); | |
410 | ||
411 | /* Already gone? */ | |
412 | if (atomic_read(&dentry->d_count) == 0) | |
413 | goto next; | |
414 | ||
415 | qstr = &dentry->d_name; | |
416 | ||
417 | if (dentry->d_name.hash != hash) | |
418 | goto next; | |
419 | if (dentry->d_parent != parent) | |
420 | goto next; | |
421 | ||
422 | if (qstr->len != len) | |
423 | goto next; | |
424 | if (memcmp(qstr->name, str, len)) | |
425 | goto next; | |
426 | ||
427 | if (d_unhashed(dentry)) { | |
428 | dget(dentry); | |
429 | spin_unlock(&dentry->d_lock); | |
430 | spin_unlock(&sbi->lookup_lock); | |
431 | spin_unlock(&dcache_lock); | |
432 | return dentry; | |
433 | } | |
434 | next: | |
435 | spin_unlock(&dentry->d_lock); | |
436 | } | |
437 | spin_unlock(&sbi->lookup_lock); | |
438 | spin_unlock(&dcache_lock); | |
439 | ||
440 | return NULL; | |
441 | } | |
442 | ||
5f6f4f28 | 443 | static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name) |
f50b6f86 IK |
444 | { |
445 | unsigned int len = name->len; | |
446 | unsigned int hash = name->hash; | |
447 | const unsigned char *str = name->name; | |
448 | struct list_head *p, *head; | |
449 | ||
450 | spin_lock(&dcache_lock); | |
5f6f4f28 IK |
451 | spin_lock(&sbi->lookup_lock); |
452 | head = &sbi->expiring_list; | |
f50b6f86 IK |
453 | list_for_each(p, head) { |
454 | struct autofs_info *ino; | |
455 | struct dentry *dentry; | |
456 | struct qstr *qstr; | |
457 | ||
5f6f4f28 | 458 | ino = list_entry(p, struct autofs_info, expiring); |
f50b6f86 IK |
459 | dentry = ino->dentry; |
460 | ||
461 | spin_lock(&dentry->d_lock); | |
462 | ||
463 | /* Bad luck, we've already been dentry_iput */ | |
464 | if (!dentry->d_inode) | |
465 | goto next; | |
466 | ||
467 | qstr = &dentry->d_name; | |
468 | ||
469 | if (dentry->d_name.hash != hash) | |
470 | goto next; | |
471 | if (dentry->d_parent != parent) | |
472 | goto next; | |
473 | ||
474 | if (qstr->len != len) | |
475 | goto next; | |
476 | if (memcmp(qstr->name, str, len)) | |
477 | goto next; | |
478 | ||
479 | if (d_unhashed(dentry)) { | |
f50b6f86 | 480 | dget(dentry); |
f50b6f86 | 481 | spin_unlock(&dentry->d_lock); |
5f6f4f28 | 482 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
483 | spin_unlock(&dcache_lock); |
484 | return dentry; | |
485 | } | |
486 | next: | |
487 | spin_unlock(&dentry->d_lock); | |
488 | } | |
5f6f4f28 | 489 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
490 | spin_unlock(&dcache_lock); |
491 | ||
492 | return NULL; | |
493 | } | |
494 | ||
1da177e4 LT |
495 | /* Lookups in the root directory */ |
496 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
497 | { | |
498 | struct autofs_sb_info *sbi; | |
25767378 IK |
499 | struct autofs_info *ino; |
500 | struct dentry *expiring, *unhashed; | |
1da177e4 LT |
501 | int oz_mode; |
502 | ||
503 | DPRINTK("name = %.*s", | |
504 | dentry->d_name.len, dentry->d_name.name); | |
505 | ||
718c604a | 506 | /* File name too long to exist */ |
1da177e4 | 507 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 508 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
509 | |
510 | sbi = autofs4_sbi(dir->i_sb); | |
1da177e4 | 511 | oz_mode = autofs4_oz_mode(sbi); |
718c604a | 512 | |
1da177e4 | 513 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
a47afb0f | 514 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); |
1da177e4 | 515 | |
5f6f4f28 IK |
516 | expiring = autofs4_lookup_expiring(sbi, dentry->d_parent, &dentry->d_name); |
517 | if (expiring) { | |
f50b6f86 IK |
518 | /* |
519 | * If we are racing with expire the request might not | |
520 | * be quite complete but the directory has been removed | |
521 | * so it must have been successful, so just wait for it. | |
522 | */ | |
25767378 | 523 | ino = autofs4_dentry_ino(expiring); |
1864f7bd | 524 | while (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { |
f50b6f86 | 525 | DPRINTK("wait for incomplete expire %p name=%.*s", |
5f6f4f28 IK |
526 | expiring, expiring->d_name.len, |
527 | expiring->d_name.name); | |
528 | autofs4_wait(sbi, expiring, NFY_NONE); | |
f50b6f86 IK |
529 | DPRINTK("request completed"); |
530 | } | |
5f6f4f28 IK |
531 | spin_lock(&sbi->lookup_lock); |
532 | if (!list_empty(&ino->expiring)) | |
533 | list_del_init(&ino->expiring); | |
534 | spin_unlock(&sbi->lookup_lock); | |
535 | dput(expiring); | |
f50b6f86 | 536 | } |
1da177e4 | 537 | |
25767378 IK |
538 | unhashed = autofs4_lookup_active(sbi, dentry->d_parent, &dentry->d_name); |
539 | if (unhashed) | |
540 | dentry = unhashed; | |
541 | else { | |
542 | /* | |
543 | * Mark the dentry incomplete but don't hash it. We do this | |
544 | * to serialize our inode creation operations (symlink and | |
545 | * mkdir) which prevents deadlock during the callback to | |
546 | * the daemon. Subsequent user space lookups for the same | |
547 | * dentry are placed on the wait queue while the daemon | |
548 | * itself is allowed passage unresticted so the create | |
549 | * operation itself can then hash the dentry. Finally, | |
550 | * we check for the hashed dentry and return the newly | |
551 | * hashed dentry. | |
552 | */ | |
553 | dentry->d_op = &autofs4_root_dentry_operations; | |
554 | ||
555 | /* | |
556 | * And we need to ensure that the same dentry is used for | |
557 | * all following lookup calls until it is hashed so that | |
558 | * the dentry flags are persistent throughout the request. | |
559 | */ | |
560 | ino = autofs4_init_ino(NULL, sbi, 0555); | |
561 | if (!ino) | |
562 | return ERR_PTR(-ENOMEM); | |
563 | ||
564 | dentry->d_fsdata = ino; | |
565 | ino->dentry = dentry; | |
566 | ||
567 | spin_lock(&sbi->lookup_lock); | |
568 | list_add(&ino->active, &sbi->active_list); | |
569 | spin_unlock(&sbi->lookup_lock); | |
5f6f4f28 | 570 | |
25767378 IK |
571 | d_instantiate(dentry, NULL); |
572 | } | |
5f6f4f28 | 573 | |
1da177e4 LT |
574 | if (!oz_mode) { |
575 | spin_lock(&dentry->d_lock); | |
576 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
577 | spin_unlock(&dentry->d_lock); | |
c432c258 IK |
578 | if (dentry->d_op && dentry->d_op->d_revalidate) { |
579 | mutex_unlock(&dir->i_mutex); | |
580 | (dentry->d_op->d_revalidate)(dentry, nd); | |
581 | mutex_lock(&dir->i_mutex); | |
582 | } | |
1da177e4 LT |
583 | } |
584 | ||
585 | /* | |
586 | * If we are still pending, check if we had to handle | |
587 | * a signal. If so we can force a restart.. | |
588 | */ | |
589 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { | |
590 | /* See if we were interrupted */ | |
591 | if (signal_pending(current)) { | |
592 | sigset_t *sigset = ¤t->pending.signal; | |
593 | if (sigismember (sigset, SIGKILL) || | |
594 | sigismember (sigset, SIGQUIT) || | |
595 | sigismember (sigset, SIGINT)) { | |
25767378 IK |
596 | if (unhashed) |
597 | dput(unhashed); | |
1da177e4 LT |
598 | return ERR_PTR(-ERESTARTNOINTR); |
599 | } | |
600 | } | |
25767378 IK |
601 | if (!oz_mode) { |
602 | spin_lock(&dentry->d_lock); | |
603 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
604 | spin_unlock(&dentry->d_lock); | |
605 | } | |
1da177e4 LT |
606 | } |
607 | ||
608 | /* | |
609 | * If this dentry is unhashed, then we shouldn't honour this | |
c9ffec48 IK |
610 | * lookup. Returning ENOENT here doesn't do the right thing |
611 | * for all system calls, but it should be OK for the operations | |
612 | * we permit from an autofs. | |
1da177e4 | 613 | */ |
1864f7bd | 614 | if (!oz_mode && d_unhashed(dentry)) { |
c9ffec48 IK |
615 | /* |
616 | * A user space application can (and has done in the past) | |
617 | * remove and re-create this directory during the callback. | |
618 | * This can leave us with an unhashed dentry, but a | |
619 | * successful mount! So we need to perform another | |
620 | * cached lookup in case the dentry now exists. | |
621 | */ | |
622 | struct dentry *parent = dentry->d_parent; | |
623 | struct dentry *new = d_lookup(parent, &dentry->d_name); | |
624 | if (new != NULL) | |
625 | dentry = new; | |
626 | else | |
627 | dentry = ERR_PTR(-ENOENT); | |
628 | ||
25767378 IK |
629 | if (unhashed) |
630 | dput(unhashed); | |
631 | ||
c9ffec48 | 632 | return dentry; |
f50b6f86 IK |
633 | } |
634 | ||
25767378 IK |
635 | if (unhashed) |
636 | return unhashed; | |
637 | ||
1da177e4 LT |
638 | return NULL; |
639 | } | |
640 | ||
641 | static int autofs4_dir_symlink(struct inode *dir, | |
642 | struct dentry *dentry, | |
643 | const char *symname) | |
644 | { | |
645 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
646 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 647 | struct autofs_info *p_ino; |
1da177e4 LT |
648 | struct inode *inode; |
649 | char *cp; | |
650 | ||
651 | DPRINTK("%s <- %.*s", symname, | |
652 | dentry->d_name.len, dentry->d_name.name); | |
653 | ||
654 | if (!autofs4_oz_mode(sbi)) | |
655 | return -EACCES; | |
656 | ||
657 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
25767378 IK |
658 | if (!ino) |
659 | return -ENOMEM; | |
1da177e4 | 660 | |
25767378 IK |
661 | spin_lock(&sbi->lookup_lock); |
662 | if (!list_empty(&ino->active)) | |
663 | list_del_init(&ino->active); | |
664 | spin_unlock(&sbi->lookup_lock); | |
1da177e4 | 665 | |
ef581a74 | 666 | ino->size = strlen(symname); |
25767378 IK |
667 | cp = kmalloc(ino->size + 1, GFP_KERNEL); |
668 | if (!cp) { | |
669 | if (!dentry->d_fsdata) | |
670 | kfree(ino); | |
671 | return -ENOMEM; | |
1da177e4 LT |
672 | } |
673 | ||
674 | strcpy(cp, symname); | |
675 | ||
676 | inode = autofs4_get_inode(dir->i_sb, ino); | |
25767378 IK |
677 | if (!inode) { |
678 | kfree(cp); | |
679 | if (!dentry->d_fsdata) | |
680 | kfree(ino); | |
681 | return -ENOMEM; | |
682 | } | |
1864f7bd | 683 | d_add(dentry, inode); |
1da177e4 LT |
684 | |
685 | if (dir == dir->i_sb->s_root->d_inode) | |
686 | dentry->d_op = &autofs4_root_dentry_operations; | |
687 | else | |
688 | dentry->d_op = &autofs4_dentry_operations; | |
689 | ||
690 | dentry->d_fsdata = ino; | |
691 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
692 | atomic_inc(&ino->count); |
693 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
694 | if (p_ino && dentry->d_parent != dentry) | |
695 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
696 | ino->inode = inode; |
697 | ||
25767378 | 698 | ino->u.symlink = cp; |
1da177e4 LT |
699 | dir->i_mtime = CURRENT_TIME; |
700 | ||
701 | return 0; | |
702 | } | |
703 | ||
704 | /* | |
705 | * NOTE! | |
706 | * | |
707 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
708 | * that the file no longer exists. However, doing that means that the | |
709 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 | 710 | * this, because the unlink is probably the result of an expire. |
5f6f4f28 IK |
711 | * We simply d_drop it and add it to a expiring list in the super block, |
712 | * which allows the dentry lookup to check for an incomplete expire. | |
1da177e4 LT |
713 | * |
714 | * If a process is blocked on the dentry waiting for the expire to finish, | |
715 | * it will invalidate the dentry and try to mount with a new one. | |
716 | * | |
717 | * Also see autofs4_dir_rmdir().. | |
718 | */ | |
719 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
720 | { | |
721 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
722 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 723 | struct autofs_info *p_ino; |
1da177e4 LT |
724 | |
725 | /* This allows root to remove symlinks */ | |
d78e53c8 | 726 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
727 | return -EACCES; |
728 | ||
1aff3c8b IK |
729 | if (atomic_dec_and_test(&ino->count)) { |
730 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
731 | if (p_ino && dentry->d_parent != dentry) | |
732 | atomic_dec(&p_ino->count); | |
733 | } | |
1da177e4 LT |
734 | dput(ino->dentry); |
735 | ||
736 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 737 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
738 | |
739 | dir->i_mtime = CURRENT_TIME; | |
740 | ||
f50b6f86 | 741 | spin_lock(&dcache_lock); |
5f6f4f28 | 742 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
743 | if (list_empty(&ino->expiring)) |
744 | list_add(&ino->expiring, &sbi->expiring_list); | |
5f6f4f28 | 745 | spin_unlock(&sbi->lookup_lock); |
f50b6f86 IK |
746 | spin_lock(&dentry->d_lock); |
747 | __d_drop(dentry); | |
748 | spin_unlock(&dentry->d_lock); | |
749 | spin_unlock(&dcache_lock); | |
1da177e4 LT |
750 | |
751 | return 0; | |
752 | } | |
753 | ||
754 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
755 | { | |
756 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
757 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 758 | struct autofs_info *p_ino; |
1da177e4 | 759 | |
f50b6f86 IK |
760 | DPRINTK("dentry %p, removing %.*s", |
761 | dentry, dentry->d_name.len, dentry->d_name.name); | |
762 | ||
1da177e4 LT |
763 | if (!autofs4_oz_mode(sbi)) |
764 | return -EACCES; | |
765 | ||
766 | spin_lock(&dcache_lock); | |
767 | if (!list_empty(&dentry->d_subdirs)) { | |
768 | spin_unlock(&dcache_lock); | |
769 | return -ENOTEMPTY; | |
770 | } | |
5f6f4f28 | 771 | spin_lock(&sbi->lookup_lock); |
25767378 IK |
772 | if (list_empty(&ino->expiring)) |
773 | list_add(&ino->expiring, &sbi->expiring_list); | |
5f6f4f28 | 774 | spin_unlock(&sbi->lookup_lock); |
1da177e4 LT |
775 | spin_lock(&dentry->d_lock); |
776 | __d_drop(dentry); | |
777 | spin_unlock(&dentry->d_lock); | |
778 | spin_unlock(&dcache_lock); | |
779 | ||
1aff3c8b IK |
780 | if (atomic_dec_and_test(&ino->count)) { |
781 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
782 | if (p_ino && dentry->d_parent != dentry) | |
783 | atomic_dec(&p_ino->count); | |
784 | } | |
1da177e4 | 785 | dput(ino->dentry); |
1da177e4 | 786 | dentry->d_inode->i_size = 0; |
ce71ec36 | 787 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
788 | |
789 | if (dir->i_nlink) | |
9a53c3a7 | 790 | drop_nlink(dir); |
1da177e4 LT |
791 | |
792 | return 0; | |
793 | } | |
794 | ||
795 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
796 | { | |
797 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
798 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 799 | struct autofs_info *p_ino; |
1da177e4 LT |
800 | struct inode *inode; |
801 | ||
d78e53c8 | 802 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
803 | return -EACCES; |
804 | ||
805 | DPRINTK("dentry %p, creating %.*s", | |
806 | dentry, dentry->d_name.len, dentry->d_name.name); | |
807 | ||
808 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
25767378 IK |
809 | if (!ino) |
810 | return -ENOMEM; | |
811 | ||
812 | spin_lock(&sbi->lookup_lock); | |
813 | if (!list_empty(&ino->active)) | |
814 | list_del_init(&ino->active); | |
815 | spin_unlock(&sbi->lookup_lock); | |
1da177e4 LT |
816 | |
817 | inode = autofs4_get_inode(dir->i_sb, ino); | |
25767378 IK |
818 | if (!inode) { |
819 | if (!dentry->d_fsdata) | |
820 | kfree(ino); | |
821 | return -ENOMEM; | |
822 | } | |
1864f7bd | 823 | d_add(dentry, inode); |
1da177e4 LT |
824 | |
825 | if (dir == dir->i_sb->s_root->d_inode) | |
826 | dentry->d_op = &autofs4_root_dentry_operations; | |
827 | else | |
828 | dentry->d_op = &autofs4_dentry_operations; | |
829 | ||
830 | dentry->d_fsdata = ino; | |
831 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
832 | atomic_inc(&ino->count); |
833 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
834 | if (p_ino && dentry->d_parent != dentry) | |
835 | atomic_inc(&p_ino->count); | |
1da177e4 | 836 | ino->inode = inode; |
d8c76e6f | 837 | inc_nlink(dir); |
1da177e4 LT |
838 | dir->i_mtime = CURRENT_TIME; |
839 | ||
840 | return 0; | |
841 | } | |
842 | ||
843 | /* Get/set timeout ioctl() operation */ | |
844 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, | |
845 | unsigned long __user *p) | |
846 | { | |
847 | int rv; | |
848 | unsigned long ntimeout; | |
849 | ||
d78e53c8 SB |
850 | if ((rv = get_user(ntimeout, p)) || |
851 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
852 | return rv; |
853 | ||
d78e53c8 | 854 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
855 | sbi->exp_timeout = 0; |
856 | else | |
857 | sbi->exp_timeout = ntimeout * HZ; | |
858 | ||
859 | return 0; | |
860 | } | |
861 | ||
862 | /* Return protocol version */ | |
863 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
864 | { | |
865 | return put_user(sbi->version, p); | |
866 | } | |
867 | ||
868 | /* Return protocol sub version */ | |
869 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
870 | { | |
871 | return put_user(sbi->sub_version, p); | |
872 | } | |
873 | ||
874 | /* | |
875 | * Tells the daemon whether we need to reghost or not. Also, clears | |
876 | * the reghost_needed flag. | |
877 | */ | |
878 | static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p) | |
879 | { | |
880 | int status; | |
881 | ||
882 | DPRINTK("returning %d", sbi->needs_reghost); | |
883 | ||
884 | status = put_user(sbi->needs_reghost, p); | |
d78e53c8 | 885 | if (status) |
1da177e4 LT |
886 | return status; |
887 | ||
888 | sbi->needs_reghost = 0; | |
889 | return 0; | |
890 | } | |
891 | ||
892 | /* | |
893 | * Enable / Disable reghosting ioctl() operation | |
894 | */ | |
895 | static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p) | |
896 | { | |
897 | int status; | |
898 | int val; | |
899 | ||
900 | status = get_user(val, p); | |
901 | ||
902 | DPRINTK("reghost = %d", val); | |
903 | ||
904 | if (status) | |
905 | return status; | |
906 | ||
907 | /* turn on/off reghosting, with the val */ | |
908 | sbi->reghost_enabled = val; | |
909 | return 0; | |
910 | } | |
911 | ||
912 | /* | |
913 | * Tells the daemon whether it can umount the autofs mount. | |
914 | */ | |
915 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
916 | { | |
917 | int status = 0; | |
918 | ||
e3474a8e | 919 | if (may_umount(mnt)) |
1da177e4 LT |
920 | status = 1; |
921 | ||
922 | DPRINTK("returning %d", status); | |
923 | ||
924 | status = put_user(status, p); | |
925 | ||
926 | return status; | |
927 | } | |
928 | ||
929 | /* Identify autofs4_dentries - this is so we can tell if there's | |
930 | an extra dentry refcount or not. We only hold a refcount on the | |
931 | dentry if its non-negative (ie, d_inode != NULL) | |
932 | */ | |
933 | int is_autofs4_dentry(struct dentry *dentry) | |
934 | { | |
935 | return dentry && dentry->d_inode && | |
936 | (dentry->d_op == &autofs4_root_dentry_operations || | |
937 | dentry->d_op == &autofs4_dentry_operations) && | |
938 | dentry->d_fsdata != NULL; | |
939 | } | |
940 | ||
941 | /* | |
942 | * ioctl()'s on the root directory is the chief method for the daemon to | |
943 | * generate kernel reactions | |
944 | */ | |
945 | static int autofs4_root_ioctl(struct inode *inode, struct file *filp, | |
946 | unsigned int cmd, unsigned long arg) | |
947 | { | |
948 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
949 | void __user *p = (void __user *)arg; | |
950 | ||
951 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 952 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 953 | |
d78e53c8 SB |
954 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
955 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
956 | return -ENOTTY; |
957 | ||
d78e53c8 | 958 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
959 | return -EPERM; |
960 | ||
961 | switch(cmd) { | |
962 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
963 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
964 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
965 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
966 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
967 | autofs4_catatonic_mode(sbi); | |
968 | return 0; | |
969 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
970 | return autofs4_get_protover(sbi, p); | |
971 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
972 | return autofs4_get_protosubver(sbi, p); | |
973 | case AUTOFS_IOC_SETTIMEOUT: | |
974 | return autofs4_get_set_timeout(sbi, p); | |
975 | ||
976 | case AUTOFS_IOC_TOGGLEREGHOST: | |
977 | return autofs4_toggle_reghost(sbi, p); | |
978 | case AUTOFS_IOC_ASKREGHOST: | |
979 | return autofs4_ask_reghost(sbi, p); | |
980 | ||
981 | case AUTOFS_IOC_ASKUMOUNT: | |
a4669ed8 | 982 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
983 | |
984 | /* return a single thing to expire */ | |
985 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 986 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
987 | /* same as above, but can send multiple expires through pipe */ |
988 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 989 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
990 | |
991 | default: | |
992 | return -ENOSYS; | |
993 | } | |
994 | } |