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> | |
20 | #include <linux/smp_lock.h> | |
21 | #include "autofs_i.h" | |
22 | ||
23 | static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); | |
24 | static int autofs4_dir_unlink(struct inode *,struct dentry *); | |
25 | static int autofs4_dir_rmdir(struct inode *,struct dentry *); | |
26 | static int autofs4_dir_mkdir(struct inode *,struct dentry *,int); | |
27 | static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long); | |
28 | static int autofs4_dir_open(struct inode *inode, struct file *file); | |
29 | static int autofs4_dir_close(struct inode *inode, struct file *file); | |
30 | static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir); | |
31 | static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir); | |
32 | static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); | |
34ca959c | 33 | static void *autofs4_follow_link(struct dentry *, struct nameidata *); |
1da177e4 LT |
34 | |
35 | struct file_operations autofs4_root_operations = { | |
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 | ||
43 | struct file_operations autofs4_dir_operations = { | |
44 | .open = autofs4_dir_open, | |
45 | .release = autofs4_dir_close, | |
46 | .read = generic_read_dir, | |
47 | .readdir = autofs4_dir_readdir, | |
48 | }; | |
49 | ||
34ca959c | 50 | 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 | ||
34ca959c IK |
58 | struct inode_operations autofs4_direct_root_inode_operations = { |
59 | .lookup = autofs4_lookup, | |
60 | .follow_link = autofs4_follow_link, | |
61 | }; | |
62 | ||
1da177e4 LT |
63 | struct inode_operations autofs4_dir_inode_operations = { |
64 | .lookup = autofs4_lookup, | |
65 | .unlink = autofs4_dir_unlink, | |
66 | .symlink = autofs4_dir_symlink, | |
67 | .mkdir = autofs4_dir_mkdir, | |
68 | .rmdir = autofs4_dir_rmdir, | |
69 | }; | |
70 | ||
71 | static int autofs4_root_readdir(struct file *file, void *dirent, | |
72 | filldir_t filldir) | |
73 | { | |
74 | struct autofs_sb_info *sbi = autofs4_sbi(file->f_dentry->d_sb); | |
75 | int oz_mode = autofs4_oz_mode(sbi); | |
76 | ||
77 | DPRINTK("called, filp->f_pos = %lld", file->f_pos); | |
78 | ||
79 | /* | |
80 | * Don't set reghost flag if: | |
81 | * 1) f_pos is larger than zero -- we've already been here. | |
82 | * 2) we haven't even enabled reghosting in the 1st place. | |
83 | * 3) this is the daemon doing a readdir | |
84 | */ | |
85 | if (oz_mode && file->f_pos == 0 && sbi->reghost_enabled) | |
86 | sbi->needs_reghost = 1; | |
87 | ||
88 | DPRINTK("needs_reghost = %d", sbi->needs_reghost); | |
89 | ||
f360ce3b | 90 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
91 | } |
92 | ||
1da177e4 LT |
93 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
94 | { | |
95 | struct dentry *dentry = file->f_dentry; | |
96 | struct vfsmount *mnt = file->f_vfsmnt; | |
97 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b | 98 | struct dentry *cursor; |
1da177e4 LT |
99 | int status; |
100 | ||
f360ce3b IK |
101 | status = dcache_dir_open(inode, file); |
102 | if (status) | |
103 | goto out; | |
104 | ||
105 | cursor = file->private_data; | |
106 | cursor->d_fsdata = NULL; | |
107 | ||
1da177e4 LT |
108 | DPRINTK("file=%p dentry=%p %.*s", |
109 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
110 | ||
111 | if (autofs4_oz_mode(sbi)) | |
112 | goto out; | |
113 | ||
114 | if (autofs4_ispending(dentry)) { | |
115 | DPRINTK("dentry busy"); | |
f360ce3b IK |
116 | dcache_dir_close(inode, file); |
117 | status = -EBUSY; | |
118 | goto out; | |
1da177e4 LT |
119 | } |
120 | ||
f360ce3b | 121 | status = -ENOENT; |
1da177e4 LT |
122 | if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) { |
123 | struct nameidata nd; | |
f360ce3b | 124 | int empty, ret; |
1da177e4 LT |
125 | |
126 | /* In case there are stale directory dentrys from a failed mount */ | |
127 | spin_lock(&dcache_lock); | |
128 | empty = list_empty(&dentry->d_subdirs); | |
129 | spin_unlock(&dcache_lock); | |
130 | ||
131 | if (!empty) | |
132 | d_invalidate(dentry); | |
133 | ||
134 | nd.flags = LOOKUP_DIRECTORY; | |
f360ce3b | 135 | ret = (dentry->d_op->d_revalidate)(dentry, &nd); |
1da177e4 | 136 | |
f360ce3b IK |
137 | if (!ret) { |
138 | dcache_dir_close(inode, file); | |
139 | goto out; | |
140 | } | |
1da177e4 LT |
141 | } |
142 | ||
143 | if (d_mountpoint(dentry)) { | |
144 | struct file *fp = NULL; | |
145 | struct vfsmount *fp_mnt = mntget(mnt); | |
146 | struct dentry *fp_dentry = dget(dentry); | |
147 | ||
9b1e3afd IK |
148 | if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) { |
149 | dput(fp_dentry); | |
150 | mntput(fp_mnt); | |
f360ce3b IK |
151 | dcache_dir_close(inode, file); |
152 | goto out; | |
9b1e3afd | 153 | } |
1da177e4 LT |
154 | |
155 | fp = dentry_open(fp_dentry, fp_mnt, file->f_flags); | |
156 | status = PTR_ERR(fp); | |
157 | if (IS_ERR(fp)) { | |
f360ce3b IK |
158 | dcache_dir_close(inode, file); |
159 | goto out; | |
1da177e4 | 160 | } |
f360ce3b | 161 | cursor->d_fsdata = fp; |
1da177e4 | 162 | } |
1da177e4 | 163 | return 0; |
f360ce3b IK |
164 | out: |
165 | return status; | |
1da177e4 LT |
166 | } |
167 | ||
168 | static int autofs4_dir_close(struct inode *inode, struct file *file) | |
169 | { | |
170 | struct dentry *dentry = file->f_dentry; | |
171 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b IK |
172 | struct dentry *cursor = file->private_data; |
173 | int status = 0; | |
1da177e4 LT |
174 | |
175 | DPRINTK("file=%p dentry=%p %.*s", | |
176 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
177 | ||
178 | if (autofs4_oz_mode(sbi)) | |
179 | goto out; | |
180 | ||
181 | if (autofs4_ispending(dentry)) { | |
182 | DPRINTK("dentry busy"); | |
f360ce3b IK |
183 | status = -EBUSY; |
184 | goto out; | |
1da177e4 LT |
185 | } |
186 | ||
187 | if (d_mountpoint(dentry)) { | |
f360ce3b IK |
188 | struct file *fp = cursor->d_fsdata; |
189 | if (!fp) { | |
190 | status = -ENOENT; | |
191 | goto out; | |
192 | } | |
1da177e4 | 193 | filp_close(fp, current->files); |
1da177e4 LT |
194 | } |
195 | out: | |
f360ce3b IK |
196 | dcache_dir_close(inode, file); |
197 | return status; | |
1da177e4 LT |
198 | } |
199 | ||
200 | static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir) | |
201 | { | |
202 | struct dentry *dentry = file->f_dentry; | |
203 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b | 204 | struct dentry *cursor = file->private_data; |
1da177e4 LT |
205 | int status; |
206 | ||
207 | DPRINTK("file=%p dentry=%p %.*s", | |
208 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
209 | ||
210 | if (autofs4_oz_mode(sbi)) | |
211 | goto out; | |
212 | ||
213 | if (autofs4_ispending(dentry)) { | |
214 | DPRINTK("dentry busy"); | |
215 | return -EBUSY; | |
216 | } | |
217 | ||
218 | if (d_mountpoint(dentry)) { | |
f360ce3b | 219 | struct file *fp = cursor->d_fsdata; |
1da177e4 LT |
220 | |
221 | if (!fp) | |
222 | return -ENOENT; | |
223 | ||
224 | if (!fp->f_op || !fp->f_op->readdir) | |
225 | goto out; | |
226 | ||
227 | status = vfs_readdir(fp, filldir, dirent); | |
228 | file->f_pos = fp->f_pos; | |
229 | if (status) | |
230 | autofs4_copy_atime(file, fp); | |
231 | return status; | |
232 | } | |
233 | out: | |
f360ce3b | 234 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
235 | } |
236 | ||
862b110f | 237 | static int try_to_fill_dentry(struct dentry *dentry, int flags) |
1da177e4 | 238 | { |
862b110f | 239 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
718c604a | 240 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
1da177e4 LT |
241 | int status = 0; |
242 | ||
243 | /* Block on any pending expiry here; invalidate the dentry | |
244 | when expiration is done to trigger mount request with a new | |
245 | dentry */ | |
718c604a | 246 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { |
1da177e4 LT |
247 | DPRINTK("waiting for expire %p name=%.*s", |
248 | dentry, dentry->d_name.len, dentry->d_name.name); | |
249 | ||
250 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
718c604a | 251 | |
1da177e4 | 252 | DPRINTK("expire done status=%d", status); |
718c604a | 253 | |
1684b2bb IK |
254 | /* |
255 | * If the directory still exists the mount request must | |
256 | * continue otherwise it can't be followed at the right | |
257 | * time during the walk. | |
258 | */ | |
259 | status = d_invalidate(dentry); | |
260 | if (status != -EBUSY) | |
34ca959c | 261 | return -ENOENT; |
1da177e4 LT |
262 | } |
263 | ||
264 | DPRINTK("dentry=%p %.*s ino=%p", | |
265 | dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); | |
266 | ||
718c604a IK |
267 | /* |
268 | * Wait for a pending mount, triggering one if there | |
269 | * isn't one already | |
270 | */ | |
1da177e4 LT |
271 | if (dentry->d_inode == NULL) { |
272 | DPRINTK("waiting for mount name=%.*s", | |
273 | dentry->d_name.len, dentry->d_name.name); | |
274 | ||
275 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
718c604a | 276 | |
1da177e4 LT |
277 | DPRINTK("mount done status=%d", status); |
278 | ||
279 | if (status && dentry->d_inode) | |
34ca959c | 280 | return status; /* Try to get the kernel to invalidate this dentry */ |
718c604a | 281 | |
1da177e4 LT |
282 | /* Turn this into a real negative dentry? */ |
283 | if (status == -ENOENT) { | |
1da177e4 LT |
284 | spin_lock(&dentry->d_lock); |
285 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
286 | spin_unlock(&dentry->d_lock); | |
34ca959c | 287 | return status; |
1da177e4 LT |
288 | } else if (status) { |
289 | /* Return a negative dentry, but leave it "pending" */ | |
34ca959c | 290 | return status; |
1da177e4 LT |
291 | } |
292 | /* Trigger mount for path component or follow link */ | |
293 | } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) || | |
294 | current->link_count) { | |
295 | DPRINTK("waiting for mount name=%.*s", | |
296 | dentry->d_name.len, dentry->d_name.name); | |
297 | ||
298 | spin_lock(&dentry->d_lock); | |
299 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
300 | spin_unlock(&dentry->d_lock); | |
301 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
302 | ||
303 | DPRINTK("mount done status=%d", status); | |
304 | ||
305 | if (status) { | |
306 | spin_lock(&dentry->d_lock); | |
307 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
308 | spin_unlock(&dentry->d_lock); | |
34ca959c | 309 | return status; |
1da177e4 LT |
310 | } |
311 | } | |
312 | ||
e0a7aae9 IK |
313 | /* Initialize expiry counter after successful mount */ |
314 | if (ino) | |
315 | ino->last_used = jiffies; | |
316 | ||
1da177e4 LT |
317 | spin_lock(&dentry->d_lock); |
318 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
319 | spin_unlock(&dentry->d_lock); | |
34ca959c IK |
320 | return status; |
321 | } | |
322 | ||
323 | /* For autofs direct mounts the follow link triggers the mount */ | |
324 | static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) | |
325 | { | |
326 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
327 | int oz_mode = autofs4_oz_mode(sbi); | |
328 | unsigned int lookup_type; | |
329 | int status; | |
330 | ||
331 | DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d", | |
332 | dentry, dentry->d_name.len, dentry->d_name.name, oz_mode, | |
333 | nd->flags); | |
334 | ||
335 | /* If it's our master or we shouldn't trigger a mount we're done */ | |
336 | lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY); | |
337 | if (oz_mode || !lookup_type) | |
338 | goto done; | |
339 | ||
340 | status = try_to_fill_dentry(dentry, 0); | |
341 | if (status) | |
342 | goto out_error; | |
343 | ||
344 | if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) { | |
345 | status = -ENOENT; | |
346 | goto out_error; | |
347 | } | |
348 | ||
349 | done: | |
350 | return NULL; | |
351 | ||
352 | out_error: | |
353 | path_release(nd); | |
354 | return ERR_PTR(status); | |
1da177e4 LT |
355 | } |
356 | ||
357 | /* | |
358 | * Revalidate is called on every cache lookup. Some of those | |
359 | * cache lookups may actually happen while the dentry is not | |
360 | * yet completely filled in, and revalidate has to delay such | |
361 | * lookups.. | |
362 | */ | |
718c604a | 363 | static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 364 | { |
718c604a | 365 | struct inode *dir = dentry->d_parent->d_inode; |
1da177e4 LT |
366 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
367 | int oz_mode = autofs4_oz_mode(sbi); | |
368 | int flags = nd ? nd->flags : 0; | |
34ca959c | 369 | int status = 0; |
1da177e4 LT |
370 | |
371 | /* Pending dentry */ | |
372 | if (autofs4_ispending(dentry)) { | |
373 | if (!oz_mode) | |
862b110f | 374 | status = try_to_fill_dentry(dentry, flags); |
34ca959c | 375 | return !status; |
1da177e4 LT |
376 | } |
377 | ||
378 | /* Negative dentry.. invalidate if "old" */ | |
379 | if (dentry->d_inode == NULL) | |
2d753e62 | 380 | return 0; |
1da177e4 LT |
381 | |
382 | /* Check for a non-mountpoint directory with no contents */ | |
383 | spin_lock(&dcache_lock); | |
384 | if (S_ISDIR(dentry->d_inode->i_mode) && | |
385 | !d_mountpoint(dentry) && | |
90a59c7c | 386 | __simple_empty(dentry)) { |
1da177e4 LT |
387 | DPRINTK("dentry=%p %.*s, emptydir", |
388 | dentry, dentry->d_name.len, dentry->d_name.name); | |
389 | spin_unlock(&dcache_lock); | |
390 | if (!oz_mode) | |
862b110f | 391 | status = try_to_fill_dentry(dentry, flags); |
34ca959c | 392 | return !status; |
1da177e4 LT |
393 | } |
394 | spin_unlock(&dcache_lock); | |
395 | ||
1da177e4 LT |
396 | return 1; |
397 | } | |
398 | ||
34ca959c | 399 | void autofs4_dentry_release(struct dentry *de) |
1da177e4 LT |
400 | { |
401 | struct autofs_info *inf; | |
402 | ||
403 | DPRINTK("releasing %p", de); | |
404 | ||
405 | inf = autofs4_dentry_ino(de); | |
406 | de->d_fsdata = NULL; | |
407 | ||
408 | if (inf) { | |
409 | inf->dentry = NULL; | |
410 | inf->inode = NULL; | |
411 | ||
412 | autofs4_free_ino(inf); | |
413 | } | |
414 | } | |
415 | ||
416 | /* For dentries of directories in the root dir */ | |
417 | static struct dentry_operations autofs4_root_dentry_operations = { | |
418 | .d_revalidate = autofs4_revalidate, | |
419 | .d_release = autofs4_dentry_release, | |
420 | }; | |
421 | ||
422 | /* For other dentries */ | |
423 | static struct dentry_operations autofs4_dentry_operations = { | |
424 | .d_revalidate = autofs4_revalidate, | |
425 | .d_release = autofs4_dentry_release, | |
426 | }; | |
427 | ||
428 | /* Lookups in the root directory */ | |
429 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
430 | { | |
431 | struct autofs_sb_info *sbi; | |
432 | int oz_mode; | |
433 | ||
434 | DPRINTK("name = %.*s", | |
435 | dentry->d_name.len, dentry->d_name.name); | |
436 | ||
718c604a | 437 | /* File name too long to exist */ |
1da177e4 | 438 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 439 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
440 | |
441 | sbi = autofs4_sbi(dir->i_sb); | |
1da177e4 | 442 | oz_mode = autofs4_oz_mode(sbi); |
718c604a | 443 | |
1da177e4 LT |
444 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
445 | current->pid, process_group(current), sbi->catatonic, oz_mode); | |
446 | ||
447 | /* | |
448 | * Mark the dentry incomplete, but add it. This is needed so | |
449 | * that the VFS layer knows about the dentry, and we can count | |
450 | * on catching any lookups through the revalidate. | |
451 | * | |
452 | * Let all the hard work be done by the revalidate function that | |
453 | * needs to be able to do this anyway.. | |
454 | * | |
455 | * We need to do this before we release the directory semaphore. | |
456 | */ | |
457 | dentry->d_op = &autofs4_root_dentry_operations; | |
458 | ||
459 | if (!oz_mode) { | |
460 | spin_lock(&dentry->d_lock); | |
461 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
462 | spin_unlock(&dentry->d_lock); | |
463 | } | |
464 | dentry->d_fsdata = NULL; | |
465 | d_add(dentry, NULL); | |
466 | ||
467 | if (dentry->d_op && dentry->d_op->d_revalidate) { | |
1b1dcc1b | 468 | mutex_unlock(&dir->i_mutex); |
1da177e4 | 469 | (dentry->d_op->d_revalidate)(dentry, nd); |
1b1dcc1b | 470 | mutex_lock(&dir->i_mutex); |
1da177e4 LT |
471 | } |
472 | ||
473 | /* | |
474 | * If we are still pending, check if we had to handle | |
475 | * a signal. If so we can force a restart.. | |
476 | */ | |
477 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { | |
478 | /* See if we were interrupted */ | |
479 | if (signal_pending(current)) { | |
480 | sigset_t *sigset = ¤t->pending.signal; | |
481 | if (sigismember (sigset, SIGKILL) || | |
482 | sigismember (sigset, SIGQUIT) || | |
483 | sigismember (sigset, SIGINT)) { | |
484 | return ERR_PTR(-ERESTARTNOINTR); | |
485 | } | |
486 | } | |
487 | } | |
488 | ||
489 | /* | |
490 | * If this dentry is unhashed, then we shouldn't honour this | |
491 | * lookup even if the dentry is positive. Returning ENOENT here | |
492 | * doesn't do the right thing for all system calls, but it should | |
493 | * be OK for the operations we permit from an autofs. | |
494 | */ | |
718c604a | 495 | if (dentry->d_inode && d_unhashed(dentry)) |
1da177e4 LT |
496 | return ERR_PTR(-ENOENT); |
497 | ||
498 | return NULL; | |
499 | } | |
500 | ||
501 | static int autofs4_dir_symlink(struct inode *dir, | |
502 | struct dentry *dentry, | |
503 | const char *symname) | |
504 | { | |
505 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
506 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 507 | struct autofs_info *p_ino; |
1da177e4 LT |
508 | struct inode *inode; |
509 | char *cp; | |
510 | ||
511 | DPRINTK("%s <- %.*s", symname, | |
512 | dentry->d_name.len, dentry->d_name.name); | |
513 | ||
514 | if (!autofs4_oz_mode(sbi)) | |
515 | return -EACCES; | |
516 | ||
517 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
518 | if (ino == NULL) | |
519 | return -ENOSPC; | |
520 | ||
521 | ino->size = strlen(symname); | |
522 | ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL); | |
523 | ||
524 | if (cp == NULL) { | |
525 | kfree(ino); | |
526 | return -ENOSPC; | |
527 | } | |
528 | ||
529 | strcpy(cp, symname); | |
530 | ||
531 | inode = autofs4_get_inode(dir->i_sb, ino); | |
532 | d_instantiate(dentry, inode); | |
533 | ||
534 | if (dir == dir->i_sb->s_root->d_inode) | |
535 | dentry->d_op = &autofs4_root_dentry_operations; | |
536 | else | |
537 | dentry->d_op = &autofs4_dentry_operations; | |
538 | ||
539 | dentry->d_fsdata = ino; | |
540 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
541 | atomic_inc(&ino->count); |
542 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
543 | if (p_ino && dentry->d_parent != dentry) | |
544 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
545 | ino->inode = inode; |
546 | ||
547 | dir->i_mtime = CURRENT_TIME; | |
548 | ||
549 | return 0; | |
550 | } | |
551 | ||
552 | /* | |
553 | * NOTE! | |
554 | * | |
555 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
556 | * that the file no longer exists. However, doing that means that the | |
557 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
558 | * this, because since the unlink is probably the result of an expire. | |
559 | * We simply d_drop it, which allows the dentry lookup to remount it | |
560 | * if necessary. | |
561 | * | |
562 | * If a process is blocked on the dentry waiting for the expire to finish, | |
563 | * it will invalidate the dentry and try to mount with a new one. | |
564 | * | |
565 | * Also see autofs4_dir_rmdir().. | |
566 | */ | |
567 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
568 | { | |
569 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
570 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 571 | struct autofs_info *p_ino; |
1da177e4 LT |
572 | |
573 | /* This allows root to remove symlinks */ | |
574 | if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) | |
575 | return -EACCES; | |
576 | ||
1aff3c8b IK |
577 | if (atomic_dec_and_test(&ino->count)) { |
578 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
579 | if (p_ino && dentry->d_parent != dentry) | |
580 | atomic_dec(&p_ino->count); | |
581 | } | |
1da177e4 LT |
582 | dput(ino->dentry); |
583 | ||
584 | dentry->d_inode->i_size = 0; | |
585 | dentry->d_inode->i_nlink = 0; | |
586 | ||
587 | dir->i_mtime = CURRENT_TIME; | |
588 | ||
589 | d_drop(dentry); | |
590 | ||
591 | return 0; | |
592 | } | |
593 | ||
594 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
595 | { | |
596 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
597 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 598 | struct autofs_info *p_ino; |
1da177e4 LT |
599 | |
600 | if (!autofs4_oz_mode(sbi)) | |
601 | return -EACCES; | |
602 | ||
603 | spin_lock(&dcache_lock); | |
604 | if (!list_empty(&dentry->d_subdirs)) { | |
605 | spin_unlock(&dcache_lock); | |
606 | return -ENOTEMPTY; | |
607 | } | |
608 | spin_lock(&dentry->d_lock); | |
609 | __d_drop(dentry); | |
610 | spin_unlock(&dentry->d_lock); | |
611 | spin_unlock(&dcache_lock); | |
612 | ||
1aff3c8b IK |
613 | if (atomic_dec_and_test(&ino->count)) { |
614 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
615 | if (p_ino && dentry->d_parent != dentry) | |
616 | atomic_dec(&p_ino->count); | |
617 | } | |
1da177e4 | 618 | dput(ino->dentry); |
1da177e4 LT |
619 | dentry->d_inode->i_size = 0; |
620 | dentry->d_inode->i_nlink = 0; | |
621 | ||
622 | if (dir->i_nlink) | |
623 | dir->i_nlink--; | |
624 | ||
625 | return 0; | |
626 | } | |
627 | ||
628 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
629 | { | |
630 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
631 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 632 | struct autofs_info *p_ino; |
1da177e4 LT |
633 | struct inode *inode; |
634 | ||
635 | if ( !autofs4_oz_mode(sbi) ) | |
636 | return -EACCES; | |
637 | ||
638 | DPRINTK("dentry %p, creating %.*s", | |
639 | dentry, dentry->d_name.len, dentry->d_name.name); | |
640 | ||
641 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
642 | if (ino == NULL) | |
643 | return -ENOSPC; | |
644 | ||
645 | inode = autofs4_get_inode(dir->i_sb, ino); | |
646 | d_instantiate(dentry, inode); | |
647 | ||
648 | if (dir == dir->i_sb->s_root->d_inode) | |
649 | dentry->d_op = &autofs4_root_dentry_operations; | |
650 | else | |
651 | dentry->d_op = &autofs4_dentry_operations; | |
652 | ||
653 | dentry->d_fsdata = ino; | |
654 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
655 | atomic_inc(&ino->count); |
656 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
657 | if (p_ino && dentry->d_parent != dentry) | |
658 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
659 | ino->inode = inode; |
660 | dir->i_nlink++; | |
661 | dir->i_mtime = CURRENT_TIME; | |
662 | ||
663 | return 0; | |
664 | } | |
665 | ||
666 | /* Get/set timeout ioctl() operation */ | |
667 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, | |
668 | unsigned long __user *p) | |
669 | { | |
670 | int rv; | |
671 | unsigned long ntimeout; | |
672 | ||
673 | if ( (rv = get_user(ntimeout, p)) || | |
674 | (rv = put_user(sbi->exp_timeout/HZ, p)) ) | |
675 | return rv; | |
676 | ||
677 | if ( ntimeout > ULONG_MAX/HZ ) | |
678 | sbi->exp_timeout = 0; | |
679 | else | |
680 | sbi->exp_timeout = ntimeout * HZ; | |
681 | ||
682 | return 0; | |
683 | } | |
684 | ||
685 | /* Return protocol version */ | |
686 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
687 | { | |
688 | return put_user(sbi->version, p); | |
689 | } | |
690 | ||
691 | /* Return protocol sub version */ | |
692 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
693 | { | |
694 | return put_user(sbi->sub_version, p); | |
695 | } | |
696 | ||
697 | /* | |
698 | * Tells the daemon whether we need to reghost or not. Also, clears | |
699 | * the reghost_needed flag. | |
700 | */ | |
701 | static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p) | |
702 | { | |
703 | int status; | |
704 | ||
705 | DPRINTK("returning %d", sbi->needs_reghost); | |
706 | ||
707 | status = put_user(sbi->needs_reghost, p); | |
708 | if ( status ) | |
709 | return status; | |
710 | ||
711 | sbi->needs_reghost = 0; | |
712 | return 0; | |
713 | } | |
714 | ||
715 | /* | |
716 | * Enable / Disable reghosting ioctl() operation | |
717 | */ | |
718 | static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p) | |
719 | { | |
720 | int status; | |
721 | int val; | |
722 | ||
723 | status = get_user(val, p); | |
724 | ||
725 | DPRINTK("reghost = %d", val); | |
726 | ||
727 | if (status) | |
728 | return status; | |
729 | ||
730 | /* turn on/off reghosting, with the val */ | |
731 | sbi->reghost_enabled = val; | |
732 | return 0; | |
733 | } | |
734 | ||
735 | /* | |
736 | * Tells the daemon whether it can umount the autofs mount. | |
737 | */ | |
738 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
739 | { | |
740 | int status = 0; | |
741 | ||
e3474a8e | 742 | if (may_umount(mnt)) |
1da177e4 LT |
743 | status = 1; |
744 | ||
745 | DPRINTK("returning %d", status); | |
746 | ||
747 | status = put_user(status, p); | |
748 | ||
749 | return status; | |
750 | } | |
751 | ||
752 | /* Identify autofs4_dentries - this is so we can tell if there's | |
753 | an extra dentry refcount or not. We only hold a refcount on the | |
754 | dentry if its non-negative (ie, d_inode != NULL) | |
755 | */ | |
756 | int is_autofs4_dentry(struct dentry *dentry) | |
757 | { | |
758 | return dentry && dentry->d_inode && | |
759 | (dentry->d_op == &autofs4_root_dentry_operations || | |
760 | dentry->d_op == &autofs4_dentry_operations) && | |
761 | dentry->d_fsdata != NULL; | |
762 | } | |
763 | ||
764 | /* | |
765 | * ioctl()'s on the root directory is the chief method for the daemon to | |
766 | * generate kernel reactions | |
767 | */ | |
768 | static int autofs4_root_ioctl(struct inode *inode, struct file *filp, | |
769 | unsigned int cmd, unsigned long arg) | |
770 | { | |
771 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
772 | void __user *p = (void __user *)arg; | |
773 | ||
774 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
775 | cmd,arg,sbi,process_group(current)); | |
776 | ||
777 | if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || | |
778 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT ) | |
779 | return -ENOTTY; | |
780 | ||
781 | if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) | |
782 | return -EPERM; | |
783 | ||
784 | switch(cmd) { | |
785 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
786 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
787 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
788 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
789 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
790 | autofs4_catatonic_mode(sbi); | |
791 | return 0; | |
792 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
793 | return autofs4_get_protover(sbi, p); | |
794 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
795 | return autofs4_get_protosubver(sbi, p); | |
796 | case AUTOFS_IOC_SETTIMEOUT: | |
797 | return autofs4_get_set_timeout(sbi, p); | |
798 | ||
799 | case AUTOFS_IOC_TOGGLEREGHOST: | |
800 | return autofs4_toggle_reghost(sbi, p); | |
801 | case AUTOFS_IOC_ASKREGHOST: | |
802 | return autofs4_ask_reghost(sbi, p); | |
803 | ||
804 | case AUTOFS_IOC_ASKUMOUNT: | |
805 | return autofs4_ask_umount(filp->f_vfsmnt, p); | |
806 | ||
807 | /* return a single thing to expire */ | |
808 | case AUTOFS_IOC_EXPIRE: | |
809 | return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi, p); | |
810 | /* same as above, but can send multiple expires through pipe */ | |
811 | case AUTOFS_IOC_EXPIRE_MULTI: | |
812 | return autofs4_expire_multi(inode->i_sb,filp->f_vfsmnt,sbi, p); | |
813 | ||
814 | default: | |
815 | return -ENOSYS; | |
816 | } | |
817 | } |