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> | |
7 | * Copyright 2001-2003 Ian Kent <raven@themaw.net> | |
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 *); | |
1da177e4 LT |
33 | |
34 | struct file_operations autofs4_root_operations = { | |
35 | .open = dcache_dir_open, | |
36 | .release = dcache_dir_close, | |
37 | .read = generic_read_dir, | |
38 | .readdir = autofs4_root_readdir, | |
39 | .ioctl = autofs4_root_ioctl, | |
40 | }; | |
41 | ||
42 | struct file_operations autofs4_dir_operations = { | |
43 | .open = autofs4_dir_open, | |
44 | .release = autofs4_dir_close, | |
45 | .read = generic_read_dir, | |
46 | .readdir = autofs4_dir_readdir, | |
47 | }; | |
48 | ||
49 | struct inode_operations autofs4_root_inode_operations = { | |
50 | .lookup = autofs4_lookup, | |
51 | .unlink = autofs4_dir_unlink, | |
52 | .symlink = autofs4_dir_symlink, | |
53 | .mkdir = autofs4_dir_mkdir, | |
54 | .rmdir = autofs4_dir_rmdir, | |
55 | }; | |
56 | ||
57 | struct inode_operations autofs4_dir_inode_operations = { | |
58 | .lookup = autofs4_lookup, | |
59 | .unlink = autofs4_dir_unlink, | |
60 | .symlink = autofs4_dir_symlink, | |
61 | .mkdir = autofs4_dir_mkdir, | |
62 | .rmdir = autofs4_dir_rmdir, | |
63 | }; | |
64 | ||
65 | static int autofs4_root_readdir(struct file *file, void *dirent, | |
66 | filldir_t filldir) | |
67 | { | |
68 | struct autofs_sb_info *sbi = autofs4_sbi(file->f_dentry->d_sb); | |
69 | int oz_mode = autofs4_oz_mode(sbi); | |
70 | ||
71 | DPRINTK("called, filp->f_pos = %lld", file->f_pos); | |
72 | ||
73 | /* | |
74 | * Don't set reghost flag if: | |
75 | * 1) f_pos is larger than zero -- we've already been here. | |
76 | * 2) we haven't even enabled reghosting in the 1st place. | |
77 | * 3) this is the daemon doing a readdir | |
78 | */ | |
79 | if (oz_mode && file->f_pos == 0 && sbi->reghost_enabled) | |
80 | sbi->needs_reghost = 1; | |
81 | ||
82 | DPRINTK("needs_reghost = %d", sbi->needs_reghost); | |
83 | ||
f360ce3b | 84 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
85 | } |
86 | ||
1da177e4 LT |
87 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
88 | { | |
89 | struct dentry *dentry = file->f_dentry; | |
90 | struct vfsmount *mnt = file->f_vfsmnt; | |
91 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b | 92 | struct dentry *cursor; |
1da177e4 LT |
93 | int status; |
94 | ||
f360ce3b IK |
95 | status = dcache_dir_open(inode, file); |
96 | if (status) | |
97 | goto out; | |
98 | ||
99 | cursor = file->private_data; | |
100 | cursor->d_fsdata = NULL; | |
101 | ||
1da177e4 LT |
102 | DPRINTK("file=%p dentry=%p %.*s", |
103 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
104 | ||
105 | if (autofs4_oz_mode(sbi)) | |
106 | goto out; | |
107 | ||
108 | if (autofs4_ispending(dentry)) { | |
109 | DPRINTK("dentry busy"); | |
f360ce3b IK |
110 | dcache_dir_close(inode, file); |
111 | status = -EBUSY; | |
112 | goto out; | |
1da177e4 LT |
113 | } |
114 | ||
f360ce3b | 115 | status = -ENOENT; |
1da177e4 LT |
116 | if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) { |
117 | struct nameidata nd; | |
f360ce3b | 118 | int empty, ret; |
1da177e4 LT |
119 | |
120 | /* In case there are stale directory dentrys from a failed mount */ | |
121 | spin_lock(&dcache_lock); | |
122 | empty = list_empty(&dentry->d_subdirs); | |
123 | spin_unlock(&dcache_lock); | |
124 | ||
125 | if (!empty) | |
126 | d_invalidate(dentry); | |
127 | ||
128 | nd.flags = LOOKUP_DIRECTORY; | |
f360ce3b | 129 | ret = (dentry->d_op->d_revalidate)(dentry, &nd); |
1da177e4 | 130 | |
f360ce3b IK |
131 | if (!ret) { |
132 | dcache_dir_close(inode, file); | |
133 | goto out; | |
134 | } | |
1da177e4 LT |
135 | } |
136 | ||
137 | if (d_mountpoint(dentry)) { | |
138 | struct file *fp = NULL; | |
139 | struct vfsmount *fp_mnt = mntget(mnt); | |
140 | struct dentry *fp_dentry = dget(dentry); | |
141 | ||
9b1e3afd IK |
142 | if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) { |
143 | dput(fp_dentry); | |
144 | mntput(fp_mnt); | |
f360ce3b IK |
145 | dcache_dir_close(inode, file); |
146 | goto out; | |
9b1e3afd | 147 | } |
1da177e4 LT |
148 | |
149 | fp = dentry_open(fp_dentry, fp_mnt, file->f_flags); | |
150 | status = PTR_ERR(fp); | |
151 | if (IS_ERR(fp)) { | |
f360ce3b IK |
152 | dcache_dir_close(inode, file); |
153 | goto out; | |
1da177e4 | 154 | } |
f360ce3b | 155 | cursor->d_fsdata = fp; |
1da177e4 | 156 | } |
1da177e4 | 157 | return 0; |
f360ce3b IK |
158 | out: |
159 | return status; | |
1da177e4 LT |
160 | } |
161 | ||
162 | static int autofs4_dir_close(struct inode *inode, struct file *file) | |
163 | { | |
164 | struct dentry *dentry = file->f_dentry; | |
165 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b IK |
166 | struct dentry *cursor = file->private_data; |
167 | int status = 0; | |
1da177e4 LT |
168 | |
169 | DPRINTK("file=%p dentry=%p %.*s", | |
170 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
171 | ||
172 | if (autofs4_oz_mode(sbi)) | |
173 | goto out; | |
174 | ||
175 | if (autofs4_ispending(dentry)) { | |
176 | DPRINTK("dentry busy"); | |
f360ce3b IK |
177 | status = -EBUSY; |
178 | goto out; | |
1da177e4 LT |
179 | } |
180 | ||
181 | if (d_mountpoint(dentry)) { | |
f360ce3b IK |
182 | struct file *fp = cursor->d_fsdata; |
183 | if (!fp) { | |
184 | status = -ENOENT; | |
185 | goto out; | |
186 | } | |
1da177e4 | 187 | filp_close(fp, current->files); |
1da177e4 LT |
188 | } |
189 | out: | |
f360ce3b IK |
190 | dcache_dir_close(inode, file); |
191 | return status; | |
1da177e4 LT |
192 | } |
193 | ||
194 | static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir) | |
195 | { | |
196 | struct dentry *dentry = file->f_dentry; | |
197 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b | 198 | struct dentry *cursor = file->private_data; |
1da177e4 LT |
199 | int status; |
200 | ||
201 | DPRINTK("file=%p dentry=%p %.*s", | |
202 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
203 | ||
204 | if (autofs4_oz_mode(sbi)) | |
205 | goto out; | |
206 | ||
207 | if (autofs4_ispending(dentry)) { | |
208 | DPRINTK("dentry busy"); | |
209 | return -EBUSY; | |
210 | } | |
211 | ||
212 | if (d_mountpoint(dentry)) { | |
f360ce3b | 213 | struct file *fp = cursor->d_fsdata; |
1da177e4 LT |
214 | |
215 | if (!fp) | |
216 | return -ENOENT; | |
217 | ||
218 | if (!fp->f_op || !fp->f_op->readdir) | |
219 | goto out; | |
220 | ||
221 | status = vfs_readdir(fp, filldir, dirent); | |
222 | file->f_pos = fp->f_pos; | |
223 | if (status) | |
224 | autofs4_copy_atime(file, fp); | |
225 | return status; | |
226 | } | |
227 | out: | |
f360ce3b | 228 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
229 | } |
230 | ||
862b110f | 231 | static int try_to_fill_dentry(struct dentry *dentry, int flags) |
1da177e4 | 232 | { |
862b110f | 233 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
718c604a | 234 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
1da177e4 LT |
235 | int status = 0; |
236 | ||
237 | /* Block on any pending expiry here; invalidate the dentry | |
238 | when expiration is done to trigger mount request with a new | |
239 | dentry */ | |
718c604a | 240 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { |
1da177e4 LT |
241 | DPRINTK("waiting for expire %p name=%.*s", |
242 | dentry, dentry->d_name.len, dentry->d_name.name); | |
243 | ||
244 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
718c604a | 245 | |
1da177e4 | 246 | DPRINTK("expire done status=%d", status); |
718c604a | 247 | |
1684b2bb IK |
248 | /* |
249 | * If the directory still exists the mount request must | |
250 | * continue otherwise it can't be followed at the right | |
251 | * time during the walk. | |
252 | */ | |
253 | status = d_invalidate(dentry); | |
254 | if (status != -EBUSY) | |
255 | return 0; | |
1da177e4 LT |
256 | } |
257 | ||
258 | DPRINTK("dentry=%p %.*s ino=%p", | |
259 | dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); | |
260 | ||
718c604a IK |
261 | /* |
262 | * Wait for a pending mount, triggering one if there | |
263 | * isn't one already | |
264 | */ | |
1da177e4 LT |
265 | if (dentry->d_inode == NULL) { |
266 | DPRINTK("waiting for mount name=%.*s", | |
267 | dentry->d_name.len, dentry->d_name.name); | |
268 | ||
269 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
718c604a | 270 | |
1da177e4 LT |
271 | DPRINTK("mount done status=%d", status); |
272 | ||
273 | if (status && dentry->d_inode) | |
274 | return 0; /* Try to get the kernel to invalidate this dentry */ | |
718c604a | 275 | |
1da177e4 LT |
276 | /* Turn this into a real negative dentry? */ |
277 | if (status == -ENOENT) { | |
1da177e4 LT |
278 | spin_lock(&dentry->d_lock); |
279 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
280 | spin_unlock(&dentry->d_lock); | |
2d753e62 | 281 | return 0; |
1da177e4 LT |
282 | } else if (status) { |
283 | /* Return a negative dentry, but leave it "pending" */ | |
2d753e62 | 284 | return 0; |
1da177e4 LT |
285 | } |
286 | /* Trigger mount for path component or follow link */ | |
287 | } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) || | |
288 | current->link_count) { | |
289 | DPRINTK("waiting for mount name=%.*s", | |
290 | dentry->d_name.len, dentry->d_name.name); | |
291 | ||
292 | spin_lock(&dentry->d_lock); | |
293 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
294 | spin_unlock(&dentry->d_lock); | |
295 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
296 | ||
297 | DPRINTK("mount done status=%d", status); | |
298 | ||
299 | if (status) { | |
300 | spin_lock(&dentry->d_lock); | |
301 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
302 | spin_unlock(&dentry->d_lock); | |
303 | return 0; | |
304 | } | |
305 | } | |
306 | ||
e0a7aae9 IK |
307 | /* Initialize expiry counter after successful mount */ |
308 | if (ino) | |
309 | ino->last_used = jiffies; | |
310 | ||
1da177e4 LT |
311 | spin_lock(&dentry->d_lock); |
312 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
313 | spin_unlock(&dentry->d_lock); | |
314 | return 1; | |
315 | } | |
316 | ||
317 | /* | |
318 | * Revalidate is called on every cache lookup. Some of those | |
319 | * cache lookups may actually happen while the dentry is not | |
320 | * yet completely filled in, and revalidate has to delay such | |
321 | * lookups.. | |
322 | */ | |
718c604a | 323 | static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 324 | { |
718c604a | 325 | struct inode *dir = dentry->d_parent->d_inode; |
1da177e4 LT |
326 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
327 | int oz_mode = autofs4_oz_mode(sbi); | |
328 | int flags = nd ? nd->flags : 0; | |
329 | int status = 1; | |
330 | ||
331 | /* Pending dentry */ | |
332 | if (autofs4_ispending(dentry)) { | |
333 | if (!oz_mode) | |
862b110f | 334 | status = try_to_fill_dentry(dentry, flags); |
1da177e4 LT |
335 | return status; |
336 | } | |
337 | ||
338 | /* Negative dentry.. invalidate if "old" */ | |
339 | if (dentry->d_inode == NULL) | |
2d753e62 | 340 | return 0; |
1da177e4 LT |
341 | |
342 | /* Check for a non-mountpoint directory with no contents */ | |
343 | spin_lock(&dcache_lock); | |
344 | if (S_ISDIR(dentry->d_inode->i_mode) && | |
345 | !d_mountpoint(dentry) && | |
2d753e62 | 346 | simple_empty_nolock(dentry)) { |
1da177e4 LT |
347 | DPRINTK("dentry=%p %.*s, emptydir", |
348 | dentry, dentry->d_name.len, dentry->d_name.name); | |
349 | spin_unlock(&dcache_lock); | |
350 | if (!oz_mode) | |
862b110f | 351 | status = try_to_fill_dentry(dentry, flags); |
1da177e4 LT |
352 | return status; |
353 | } | |
354 | spin_unlock(&dcache_lock); | |
355 | ||
1da177e4 LT |
356 | return 1; |
357 | } | |
358 | ||
359 | static void autofs4_dentry_release(struct dentry *de) | |
360 | { | |
361 | struct autofs_info *inf; | |
362 | ||
363 | DPRINTK("releasing %p", de); | |
364 | ||
365 | inf = autofs4_dentry_ino(de); | |
366 | de->d_fsdata = NULL; | |
367 | ||
368 | if (inf) { | |
369 | inf->dentry = NULL; | |
370 | inf->inode = NULL; | |
371 | ||
372 | autofs4_free_ino(inf); | |
373 | } | |
374 | } | |
375 | ||
376 | /* For dentries of directories in the root dir */ | |
377 | static struct dentry_operations autofs4_root_dentry_operations = { | |
378 | .d_revalidate = autofs4_revalidate, | |
379 | .d_release = autofs4_dentry_release, | |
380 | }; | |
381 | ||
382 | /* For other dentries */ | |
383 | static struct dentry_operations autofs4_dentry_operations = { | |
384 | .d_revalidate = autofs4_revalidate, | |
385 | .d_release = autofs4_dentry_release, | |
386 | }; | |
387 | ||
388 | /* Lookups in the root directory */ | |
389 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
390 | { | |
391 | struct autofs_sb_info *sbi; | |
392 | int oz_mode; | |
393 | ||
394 | DPRINTK("name = %.*s", | |
395 | dentry->d_name.len, dentry->d_name.name); | |
396 | ||
718c604a | 397 | /* File name too long to exist */ |
1da177e4 | 398 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 399 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
400 | |
401 | sbi = autofs4_sbi(dir->i_sb); | |
1da177e4 | 402 | oz_mode = autofs4_oz_mode(sbi); |
718c604a | 403 | |
1da177e4 LT |
404 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
405 | current->pid, process_group(current), sbi->catatonic, oz_mode); | |
406 | ||
407 | /* | |
408 | * Mark the dentry incomplete, but add it. This is needed so | |
409 | * that the VFS layer knows about the dentry, and we can count | |
410 | * on catching any lookups through the revalidate. | |
411 | * | |
412 | * Let all the hard work be done by the revalidate function that | |
413 | * needs to be able to do this anyway.. | |
414 | * | |
415 | * We need to do this before we release the directory semaphore. | |
416 | */ | |
417 | dentry->d_op = &autofs4_root_dentry_operations; | |
418 | ||
419 | if (!oz_mode) { | |
420 | spin_lock(&dentry->d_lock); | |
421 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
422 | spin_unlock(&dentry->d_lock); | |
423 | } | |
424 | dentry->d_fsdata = NULL; | |
425 | d_add(dentry, NULL); | |
426 | ||
427 | if (dentry->d_op && dentry->d_op->d_revalidate) { | |
1b1dcc1b | 428 | mutex_unlock(&dir->i_mutex); |
1da177e4 | 429 | (dentry->d_op->d_revalidate)(dentry, nd); |
1b1dcc1b | 430 | mutex_lock(&dir->i_mutex); |
1da177e4 LT |
431 | } |
432 | ||
433 | /* | |
434 | * If we are still pending, check if we had to handle | |
435 | * a signal. If so we can force a restart.. | |
436 | */ | |
437 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { | |
438 | /* See if we were interrupted */ | |
439 | if (signal_pending(current)) { | |
440 | sigset_t *sigset = ¤t->pending.signal; | |
441 | if (sigismember (sigset, SIGKILL) || | |
442 | sigismember (sigset, SIGQUIT) || | |
443 | sigismember (sigset, SIGINT)) { | |
444 | return ERR_PTR(-ERESTARTNOINTR); | |
445 | } | |
446 | } | |
447 | } | |
448 | ||
449 | /* | |
450 | * If this dentry is unhashed, then we shouldn't honour this | |
451 | * lookup even if the dentry is positive. Returning ENOENT here | |
452 | * doesn't do the right thing for all system calls, but it should | |
453 | * be OK for the operations we permit from an autofs. | |
454 | */ | |
718c604a | 455 | if (dentry->d_inode && d_unhashed(dentry)) |
1da177e4 LT |
456 | return ERR_PTR(-ENOENT); |
457 | ||
458 | return NULL; | |
459 | } | |
460 | ||
461 | static int autofs4_dir_symlink(struct inode *dir, | |
462 | struct dentry *dentry, | |
463 | const char *symname) | |
464 | { | |
465 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
466 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 467 | struct autofs_info *p_ino; |
1da177e4 LT |
468 | struct inode *inode; |
469 | char *cp; | |
470 | ||
471 | DPRINTK("%s <- %.*s", symname, | |
472 | dentry->d_name.len, dentry->d_name.name); | |
473 | ||
474 | if (!autofs4_oz_mode(sbi)) | |
475 | return -EACCES; | |
476 | ||
477 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
478 | if (ino == NULL) | |
479 | return -ENOSPC; | |
480 | ||
481 | ino->size = strlen(symname); | |
482 | ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL); | |
483 | ||
484 | if (cp == NULL) { | |
485 | kfree(ino); | |
486 | return -ENOSPC; | |
487 | } | |
488 | ||
489 | strcpy(cp, symname); | |
490 | ||
491 | inode = autofs4_get_inode(dir->i_sb, ino); | |
492 | d_instantiate(dentry, inode); | |
493 | ||
494 | if (dir == dir->i_sb->s_root->d_inode) | |
495 | dentry->d_op = &autofs4_root_dentry_operations; | |
496 | else | |
497 | dentry->d_op = &autofs4_dentry_operations; | |
498 | ||
499 | dentry->d_fsdata = ino; | |
500 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
501 | atomic_inc(&ino->count); |
502 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
503 | if (p_ino && dentry->d_parent != dentry) | |
504 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
505 | ino->inode = inode; |
506 | ||
507 | dir->i_mtime = CURRENT_TIME; | |
508 | ||
509 | return 0; | |
510 | } | |
511 | ||
512 | /* | |
513 | * NOTE! | |
514 | * | |
515 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
516 | * that the file no longer exists. However, doing that means that the | |
517 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
518 | * this, because since the unlink is probably the result of an expire. | |
519 | * We simply d_drop it, which allows the dentry lookup to remount it | |
520 | * if necessary. | |
521 | * | |
522 | * If a process is blocked on the dentry waiting for the expire to finish, | |
523 | * it will invalidate the dentry and try to mount with a new one. | |
524 | * | |
525 | * Also see autofs4_dir_rmdir().. | |
526 | */ | |
527 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
528 | { | |
529 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
530 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 531 | struct autofs_info *p_ino; |
1da177e4 LT |
532 | |
533 | /* This allows root to remove symlinks */ | |
534 | if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) | |
535 | return -EACCES; | |
536 | ||
1aff3c8b IK |
537 | if (atomic_dec_and_test(&ino->count)) { |
538 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
539 | if (p_ino && dentry->d_parent != dentry) | |
540 | atomic_dec(&p_ino->count); | |
541 | } | |
1da177e4 LT |
542 | dput(ino->dentry); |
543 | ||
544 | dentry->d_inode->i_size = 0; | |
545 | dentry->d_inode->i_nlink = 0; | |
546 | ||
547 | dir->i_mtime = CURRENT_TIME; | |
548 | ||
549 | d_drop(dentry); | |
550 | ||
551 | return 0; | |
552 | } | |
553 | ||
554 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
555 | { | |
556 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
557 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 558 | struct autofs_info *p_ino; |
1da177e4 LT |
559 | |
560 | if (!autofs4_oz_mode(sbi)) | |
561 | return -EACCES; | |
562 | ||
563 | spin_lock(&dcache_lock); | |
564 | if (!list_empty(&dentry->d_subdirs)) { | |
565 | spin_unlock(&dcache_lock); | |
566 | return -ENOTEMPTY; | |
567 | } | |
568 | spin_lock(&dentry->d_lock); | |
569 | __d_drop(dentry); | |
570 | spin_unlock(&dentry->d_lock); | |
571 | spin_unlock(&dcache_lock); | |
572 | ||
1aff3c8b IK |
573 | if (atomic_dec_and_test(&ino->count)) { |
574 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
575 | if (p_ino && dentry->d_parent != dentry) | |
576 | atomic_dec(&p_ino->count); | |
577 | } | |
1da177e4 | 578 | dput(ino->dentry); |
1da177e4 LT |
579 | dentry->d_inode->i_size = 0; |
580 | dentry->d_inode->i_nlink = 0; | |
581 | ||
582 | if (dir->i_nlink) | |
583 | dir->i_nlink--; | |
584 | ||
585 | return 0; | |
586 | } | |
587 | ||
588 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
589 | { | |
590 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
591 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 592 | struct autofs_info *p_ino; |
1da177e4 LT |
593 | struct inode *inode; |
594 | ||
595 | if ( !autofs4_oz_mode(sbi) ) | |
596 | return -EACCES; | |
597 | ||
598 | DPRINTK("dentry %p, creating %.*s", | |
599 | dentry, dentry->d_name.len, dentry->d_name.name); | |
600 | ||
601 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
602 | if (ino == NULL) | |
603 | return -ENOSPC; | |
604 | ||
605 | inode = autofs4_get_inode(dir->i_sb, ino); | |
606 | d_instantiate(dentry, inode); | |
607 | ||
608 | if (dir == dir->i_sb->s_root->d_inode) | |
609 | dentry->d_op = &autofs4_root_dentry_operations; | |
610 | else | |
611 | dentry->d_op = &autofs4_dentry_operations; | |
612 | ||
613 | dentry->d_fsdata = ino; | |
614 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
615 | atomic_inc(&ino->count); |
616 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
617 | if (p_ino && dentry->d_parent != dentry) | |
618 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
619 | ino->inode = inode; |
620 | dir->i_nlink++; | |
621 | dir->i_mtime = CURRENT_TIME; | |
622 | ||
623 | return 0; | |
624 | } | |
625 | ||
626 | /* Get/set timeout ioctl() operation */ | |
627 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, | |
628 | unsigned long __user *p) | |
629 | { | |
630 | int rv; | |
631 | unsigned long ntimeout; | |
632 | ||
633 | if ( (rv = get_user(ntimeout, p)) || | |
634 | (rv = put_user(sbi->exp_timeout/HZ, p)) ) | |
635 | return rv; | |
636 | ||
637 | if ( ntimeout > ULONG_MAX/HZ ) | |
638 | sbi->exp_timeout = 0; | |
639 | else | |
640 | sbi->exp_timeout = ntimeout * HZ; | |
641 | ||
642 | return 0; | |
643 | } | |
644 | ||
645 | /* Return protocol version */ | |
646 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
647 | { | |
648 | return put_user(sbi->version, p); | |
649 | } | |
650 | ||
651 | /* Return protocol sub version */ | |
652 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
653 | { | |
654 | return put_user(sbi->sub_version, p); | |
655 | } | |
656 | ||
657 | /* | |
658 | * Tells the daemon whether we need to reghost or not. Also, clears | |
659 | * the reghost_needed flag. | |
660 | */ | |
661 | static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p) | |
662 | { | |
663 | int status; | |
664 | ||
665 | DPRINTK("returning %d", sbi->needs_reghost); | |
666 | ||
667 | status = put_user(sbi->needs_reghost, p); | |
668 | if ( status ) | |
669 | return status; | |
670 | ||
671 | sbi->needs_reghost = 0; | |
672 | return 0; | |
673 | } | |
674 | ||
675 | /* | |
676 | * Enable / Disable reghosting ioctl() operation | |
677 | */ | |
678 | static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p) | |
679 | { | |
680 | int status; | |
681 | int val; | |
682 | ||
683 | status = get_user(val, p); | |
684 | ||
685 | DPRINTK("reghost = %d", val); | |
686 | ||
687 | if (status) | |
688 | return status; | |
689 | ||
690 | /* turn on/off reghosting, with the val */ | |
691 | sbi->reghost_enabled = val; | |
692 | return 0; | |
693 | } | |
694 | ||
695 | /* | |
696 | * Tells the daemon whether it can umount the autofs mount. | |
697 | */ | |
698 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
699 | { | |
700 | int status = 0; | |
701 | ||
702 | if (may_umount(mnt) == 0) | |
703 | status = 1; | |
704 | ||
705 | DPRINTK("returning %d", status); | |
706 | ||
707 | status = put_user(status, p); | |
708 | ||
709 | return status; | |
710 | } | |
711 | ||
712 | /* Identify autofs4_dentries - this is so we can tell if there's | |
713 | an extra dentry refcount or not. We only hold a refcount on the | |
714 | dentry if its non-negative (ie, d_inode != NULL) | |
715 | */ | |
716 | int is_autofs4_dentry(struct dentry *dentry) | |
717 | { | |
718 | return dentry && dentry->d_inode && | |
719 | (dentry->d_op == &autofs4_root_dentry_operations || | |
720 | dentry->d_op == &autofs4_dentry_operations) && | |
721 | dentry->d_fsdata != NULL; | |
722 | } | |
723 | ||
724 | /* | |
725 | * ioctl()'s on the root directory is the chief method for the daemon to | |
726 | * generate kernel reactions | |
727 | */ | |
728 | static int autofs4_root_ioctl(struct inode *inode, struct file *filp, | |
729 | unsigned int cmd, unsigned long arg) | |
730 | { | |
731 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
732 | void __user *p = (void __user *)arg; | |
733 | ||
734 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
735 | cmd,arg,sbi,process_group(current)); | |
736 | ||
737 | if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || | |
738 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT ) | |
739 | return -ENOTTY; | |
740 | ||
741 | if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) | |
742 | return -EPERM; | |
743 | ||
744 | switch(cmd) { | |
745 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
746 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
747 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
748 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
749 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
750 | autofs4_catatonic_mode(sbi); | |
751 | return 0; | |
752 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
753 | return autofs4_get_protover(sbi, p); | |
754 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
755 | return autofs4_get_protosubver(sbi, p); | |
756 | case AUTOFS_IOC_SETTIMEOUT: | |
757 | return autofs4_get_set_timeout(sbi, p); | |
758 | ||
759 | case AUTOFS_IOC_TOGGLEREGHOST: | |
760 | return autofs4_toggle_reghost(sbi, p); | |
761 | case AUTOFS_IOC_ASKREGHOST: | |
762 | return autofs4_ask_reghost(sbi, p); | |
763 | ||
764 | case AUTOFS_IOC_ASKUMOUNT: | |
765 | return autofs4_ask_umount(filp->f_vfsmnt, p); | |
766 | ||
767 | /* return a single thing to expire */ | |
768 | case AUTOFS_IOC_EXPIRE: | |
769 | return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi, p); | |
770 | /* same as above, but can send multiple expires through pipe */ | |
771 | case AUTOFS_IOC_EXPIRE_MULTI: | |
772 | return autofs4_expire_multi(inode->i_sb,filp->f_vfsmnt,sbi, p); | |
773 | ||
774 | default: | |
775 | return -ENOSYS; | |
776 | } | |
777 | } |