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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/autofs4/root.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/autofs4/root.c')
-rw-r--r--fs/autofs4/root.c808
1 files changed, 808 insertions, 0 deletions
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
new file mode 100644
index 000000000000..3765c047f157
--- /dev/null
+++ b/fs/autofs4/root.c
@@ -0,0 +1,808 @@
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
15#include <linux/errno.h>
16#include <linux/stat.h>
17#include <linux/param.h>
18#include <linux/time.h>
19#include <linux/smp_lock.h>
20#include "autofs_i.h"
21
22static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
23static int autofs4_dir_unlink(struct inode *,struct dentry *);
24static int autofs4_dir_rmdir(struct inode *,struct dentry *);
25static int autofs4_dir_mkdir(struct inode *,struct dentry *,int);
26static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
27static int autofs4_dir_open(struct inode *inode, struct file *file);
28static int autofs4_dir_close(struct inode *inode, struct file *file);
29static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);
30static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
31static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
32static int autofs4_dcache_readdir(struct file *, void *, filldir_t);
33
34struct 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
42struct 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
49struct 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
57struct 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
65static 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
84 return autofs4_dcache_readdir(file, dirent, filldir);
85}
86
87/* Update usage from here to top of tree, so that scan of
88 top-level directories will give a useful result */
89static void autofs4_update_usage(struct dentry *dentry)
90{
91 struct dentry *top = dentry->d_sb->s_root;
92
93 spin_lock(&dcache_lock);
94 for(; dentry != top; dentry = dentry->d_parent) {
95 struct autofs_info *ino = autofs4_dentry_ino(dentry);
96
97 if (ino) {
98 update_atime(dentry->d_inode);
99 ino->last_used = jiffies;
100 }
101 }
102 spin_unlock(&dcache_lock);
103}
104
105/*
106 * From 2.4 kernel readdir.c
107 */
108static int autofs4_dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
109{
110 int i;
111 struct dentry *dentry = filp->f_dentry;
112
113 i = filp->f_pos;
114 switch (i) {
115 case 0:
116 if (filldir(dirent, ".", 1, i, dentry->d_inode->i_ino, DT_DIR) < 0)
117 break;
118 i++;
119 filp->f_pos++;
120 /* fallthrough */
121 case 1:
122 if (filldir(dirent, "..", 2, i, dentry->d_parent->d_inode->i_ino, DT_DIR) < 0)
123 break;
124 i++;
125 filp->f_pos++;
126 /* fallthrough */
127 default: {
128 struct list_head *list;
129 int j = i-2;
130
131 spin_lock(&dcache_lock);
132 list = dentry->d_subdirs.next;
133
134 for (;;) {
135 if (list == &dentry->d_subdirs) {
136 spin_unlock(&dcache_lock);
137 return 0;
138 }
139 if (!j)
140 break;
141 j--;
142 list = list->next;
143 }
144
145 while(1) {
146 struct dentry *de = list_entry(list, struct dentry, d_child);
147
148 if (!d_unhashed(de) && de->d_inode) {
149 spin_unlock(&dcache_lock);
150 if (filldir(dirent, de->d_name.name, de->d_name.len, filp->f_pos, de->d_inode->i_ino, DT_UNKNOWN) < 0)
151 break;
152 spin_lock(&dcache_lock);
153 }
154 filp->f_pos++;
155 list = list->next;
156 if (list != &dentry->d_subdirs)
157 continue;
158 spin_unlock(&dcache_lock);
159 break;
160 }
161 }
162 }
163 return 0;
164}
165
166static int autofs4_dir_open(struct inode *inode, struct file *file)
167{
168 struct dentry *dentry = file->f_dentry;
169 struct vfsmount *mnt = file->f_vfsmnt;
170 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
171 int status;
172
173 DPRINTK("file=%p dentry=%p %.*s",
174 file, dentry, dentry->d_name.len, dentry->d_name.name);
175
176 if (autofs4_oz_mode(sbi))
177 goto out;
178
179 if (autofs4_ispending(dentry)) {
180 DPRINTK("dentry busy");
181 return -EBUSY;
182 }
183
184 if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) {
185 struct nameidata nd;
186 int empty;
187
188 /* In case there are stale directory dentrys from a failed mount */
189 spin_lock(&dcache_lock);
190 empty = list_empty(&dentry->d_subdirs);
191 spin_unlock(&dcache_lock);
192
193 if (!empty)
194 d_invalidate(dentry);
195
196 nd.flags = LOOKUP_DIRECTORY;
197 status = (dentry->d_op->d_revalidate)(dentry, &nd);
198
199 if (!status)
200 return -ENOENT;
201 }
202
203 if (d_mountpoint(dentry)) {
204 struct file *fp = NULL;
205 struct vfsmount *fp_mnt = mntget(mnt);
206 struct dentry *fp_dentry = dget(dentry);
207
208 while (follow_down(&fp_mnt, &fp_dentry) && d_mountpoint(fp_dentry));
209
210 fp = dentry_open(fp_dentry, fp_mnt, file->f_flags);
211 status = PTR_ERR(fp);
212 if (IS_ERR(fp)) {
213 file->private_data = NULL;
214 return status;
215 }
216 file->private_data = fp;
217 }
218out:
219 return 0;
220}
221
222static int autofs4_dir_close(struct inode *inode, struct file *file)
223{
224 struct dentry *dentry = file->f_dentry;
225 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
226
227 DPRINTK("file=%p dentry=%p %.*s",
228 file, dentry, dentry->d_name.len, dentry->d_name.name);
229
230 if (autofs4_oz_mode(sbi))
231 goto out;
232
233 if (autofs4_ispending(dentry)) {
234 DPRINTK("dentry busy");
235 return -EBUSY;
236 }
237
238 if (d_mountpoint(dentry)) {
239 struct file *fp = file->private_data;
240
241 if (!fp)
242 return -ENOENT;
243
244 filp_close(fp, current->files);
245 file->private_data = NULL;
246 }
247out:
248 return 0;
249}
250
251static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir)
252{
253 struct dentry *dentry = file->f_dentry;
254 struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
255 int status;
256
257 DPRINTK("file=%p dentry=%p %.*s",
258 file, dentry, dentry->d_name.len, dentry->d_name.name);
259
260 if (autofs4_oz_mode(sbi))
261 goto out;
262
263 if (autofs4_ispending(dentry)) {
264 DPRINTK("dentry busy");
265 return -EBUSY;
266 }
267
268 if (d_mountpoint(dentry)) {
269 struct file *fp = file->private_data;
270
271 if (!fp)
272 return -ENOENT;
273
274 if (!fp->f_op || !fp->f_op->readdir)
275 goto out;
276
277 status = vfs_readdir(fp, filldir, dirent);
278 file->f_pos = fp->f_pos;
279 if (status)
280 autofs4_copy_atime(file, fp);
281 return status;
282 }
283out:
284 return autofs4_dcache_readdir(file, dirent, filldir);
285}
286
287static int try_to_fill_dentry(struct dentry *dentry,
288 struct super_block *sb,
289 struct autofs_sb_info *sbi, int flags)
290{
291 struct autofs_info *de_info = autofs4_dentry_ino(dentry);
292 int status = 0;
293
294 /* Block on any pending expiry here; invalidate the dentry
295 when expiration is done to trigger mount request with a new
296 dentry */
297 if (de_info && (de_info->flags & AUTOFS_INF_EXPIRING)) {
298 DPRINTK("waiting for expire %p name=%.*s",
299 dentry, dentry->d_name.len, dentry->d_name.name);
300
301 status = autofs4_wait(sbi, dentry, NFY_NONE);
302
303 DPRINTK("expire done status=%d", status);
304
305 return 0;
306 }
307
308 DPRINTK("dentry=%p %.*s ino=%p",
309 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
310
311 /* Wait for a pending mount, triggering one if there isn't one already */
312 if (dentry->d_inode == NULL) {
313 DPRINTK("waiting for mount name=%.*s",
314 dentry->d_name.len, dentry->d_name.name);
315
316 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
317
318 DPRINTK("mount done status=%d", status);
319
320 if (status && dentry->d_inode)
321 return 0; /* Try to get the kernel to invalidate this dentry */
322
323 /* Turn this into a real negative dentry? */
324 if (status == -ENOENT) {
325 dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
326 spin_lock(&dentry->d_lock);
327 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
328 spin_unlock(&dentry->d_lock);
329 return 1;
330 } else if (status) {
331 /* Return a negative dentry, but leave it "pending" */
332 return 1;
333 }
334 /* Trigger mount for path component or follow link */
335 } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
336 current->link_count) {
337 DPRINTK("waiting for mount name=%.*s",
338 dentry->d_name.len, dentry->d_name.name);
339
340 spin_lock(&dentry->d_lock);
341 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
342 spin_unlock(&dentry->d_lock);
343 status = autofs4_wait(sbi, dentry, NFY_MOUNT);
344
345 DPRINTK("mount done status=%d", status);
346
347 if (status) {
348 spin_lock(&dentry->d_lock);
349 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
350 spin_unlock(&dentry->d_lock);
351 return 0;
352 }
353 }
354
355 /* We don't update the usages for the autofs daemon itself, this
356 is necessary for recursive autofs mounts */
357 if (!autofs4_oz_mode(sbi))
358 autofs4_update_usage(dentry);
359
360 spin_lock(&dentry->d_lock);
361 dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
362 spin_unlock(&dentry->d_lock);
363 return 1;
364}
365
366/*
367 * Revalidate is called on every cache lookup. Some of those
368 * cache lookups may actually happen while the dentry is not
369 * yet completely filled in, and revalidate has to delay such
370 * lookups..
371 */
372static int autofs4_revalidate(struct dentry * dentry, struct nameidata *nd)
373{
374 struct inode * dir = dentry->d_parent->d_inode;
375 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
376 int oz_mode = autofs4_oz_mode(sbi);
377 int flags = nd ? nd->flags : 0;
378 int status = 1;
379
380 /* Pending dentry */
381 if (autofs4_ispending(dentry)) {
382 if (!oz_mode)
383 status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags);
384 return status;
385 }
386
387 /* Negative dentry.. invalidate if "old" */
388 if (dentry->d_inode == NULL)
389 return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT);
390
391 /* Check for a non-mountpoint directory with no contents */
392 spin_lock(&dcache_lock);
393 if (S_ISDIR(dentry->d_inode->i_mode) &&
394 !d_mountpoint(dentry) &&
395 list_empty(&dentry->d_subdirs)) {
396 DPRINTK("dentry=%p %.*s, emptydir",
397 dentry, dentry->d_name.len, dentry->d_name.name);
398 spin_unlock(&dcache_lock);
399 if (!oz_mode)
400 status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags);
401 return status;
402 }
403 spin_unlock(&dcache_lock);
404
405 /* Update the usage list */
406 if (!oz_mode)
407 autofs4_update_usage(dentry);
408
409 return 1;
410}
411
412static void autofs4_dentry_release(struct dentry *de)
413{
414 struct autofs_info *inf;
415
416 DPRINTK("releasing %p", de);
417
418 inf = autofs4_dentry_ino(de);
419 de->d_fsdata = NULL;
420
421 if (inf) {
422 inf->dentry = NULL;
423 inf->inode = NULL;
424
425 autofs4_free_ino(inf);
426 }
427}
428
429/* For dentries of directories in the root dir */
430static struct dentry_operations autofs4_root_dentry_operations = {
431 .d_revalidate = autofs4_revalidate,
432 .d_release = autofs4_dentry_release,
433};
434
435/* For other dentries */
436static struct dentry_operations autofs4_dentry_operations = {
437 .d_revalidate = autofs4_revalidate,
438 .d_release = autofs4_dentry_release,
439};
440
441/* Lookups in the root directory */
442static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
443{
444 struct autofs_sb_info *sbi;
445 int oz_mode;
446
447 DPRINTK("name = %.*s",
448 dentry->d_name.len, dentry->d_name.name);
449
450 if (dentry->d_name.len > NAME_MAX)
451 return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */
452
453 sbi = autofs4_sbi(dir->i_sb);
454
455 oz_mode = autofs4_oz_mode(sbi);
456 DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
457 current->pid, process_group(current), sbi->catatonic, oz_mode);
458
459 /*
460 * Mark the dentry incomplete, but add it. This is needed so
461 * that the VFS layer knows about the dentry, and we can count
462 * on catching any lookups through the revalidate.
463 *
464 * Let all the hard work be done by the revalidate function that
465 * needs to be able to do this anyway..
466 *
467 * We need to do this before we release the directory semaphore.
468 */
469 dentry->d_op = &autofs4_root_dentry_operations;
470
471 if (!oz_mode) {
472 spin_lock(&dentry->d_lock);
473 dentry->d_flags |= DCACHE_AUTOFS_PENDING;
474 spin_unlock(&dentry->d_lock);
475 }
476 dentry->d_fsdata = NULL;
477 d_add(dentry, NULL);
478
479 if (dentry->d_op && dentry->d_op->d_revalidate) {
480 up(&dir->i_sem);
481 (dentry->d_op->d_revalidate)(dentry, nd);
482 down(&dir->i_sem);
483 }
484
485 /*
486 * If we are still pending, check if we had to handle
487 * a signal. If so we can force a restart..
488 */
489 if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
490 /* See if we were interrupted */
491 if (signal_pending(current)) {
492 sigset_t *sigset = &current->pending.signal;
493 if (sigismember (sigset, SIGKILL) ||
494 sigismember (sigset, SIGQUIT) ||
495 sigismember (sigset, SIGINT)) {
496 return ERR_PTR(-ERESTARTNOINTR);
497 }
498 }
499 }
500
501 /*
502 * If this dentry is unhashed, then we shouldn't honour this
503 * lookup even if the dentry is positive. Returning ENOENT here
504 * doesn't do the right thing for all system calls, but it should
505 * be OK for the operations we permit from an autofs.
506 */
507 if ( dentry->d_inode && d_unhashed(dentry) )
508 return ERR_PTR(-ENOENT);
509
510 return NULL;
511}
512
513static int autofs4_dir_symlink(struct inode *dir,
514 struct dentry *dentry,
515 const char *symname)
516{
517 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
518 struct autofs_info *ino = autofs4_dentry_ino(dentry);
519 struct inode *inode;
520 char *cp;
521
522 DPRINTK("%s <- %.*s", symname,
523 dentry->d_name.len, dentry->d_name.name);
524
525 if (!autofs4_oz_mode(sbi))
526 return -EACCES;
527
528 ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
529 if (ino == NULL)
530 return -ENOSPC;
531
532 ino->size = strlen(symname);
533 ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL);
534
535 if (cp == NULL) {
536 kfree(ino);
537 return -ENOSPC;
538 }
539
540 strcpy(cp, symname);
541
542 inode = autofs4_get_inode(dir->i_sb, ino);
543 d_instantiate(dentry, inode);
544
545 if (dir == dir->i_sb->s_root->d_inode)
546 dentry->d_op = &autofs4_root_dentry_operations;
547 else
548 dentry->d_op = &autofs4_dentry_operations;
549
550 dentry->d_fsdata = ino;
551 ino->dentry = dget(dentry);
552 ino->inode = inode;
553
554 dir->i_mtime = CURRENT_TIME;
555
556 return 0;
557}
558
559/*
560 * NOTE!
561 *
562 * Normal filesystems would do a "d_delete()" to tell the VFS dcache
563 * that the file no longer exists. However, doing that means that the
564 * VFS layer can turn the dentry into a negative dentry. We don't want
565 * this, because since the unlink is probably the result of an expire.
566 * We simply d_drop it, which allows the dentry lookup to remount it
567 * if necessary.
568 *
569 * If a process is blocked on the dentry waiting for the expire to finish,
570 * it will invalidate the dentry and try to mount with a new one.
571 *
572 * Also see autofs4_dir_rmdir()..
573 */
574static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
575{
576 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
577 struct autofs_info *ino = autofs4_dentry_ino(dentry);
578
579 /* This allows root to remove symlinks */
580 if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
581 return -EACCES;
582
583 dput(ino->dentry);
584
585 dentry->d_inode->i_size = 0;
586 dentry->d_inode->i_nlink = 0;
587
588 dir->i_mtime = CURRENT_TIME;
589
590 d_drop(dentry);
591
592 return 0;
593}
594
595static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
596{
597 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
598 struct autofs_info *ino = autofs4_dentry_ino(dentry);
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
613 dput(ino->dentry);
614
615 dentry->d_inode->i_size = 0;
616 dentry->d_inode->i_nlink = 0;
617
618 if (dir->i_nlink)
619 dir->i_nlink--;
620
621 return 0;
622}
623
624static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
625{
626 struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
627 struct autofs_info *ino = autofs4_dentry_ino(dentry);
628 struct inode *inode;
629
630 if ( !autofs4_oz_mode(sbi) )
631 return -EACCES;
632
633 DPRINTK("dentry %p, creating %.*s",
634 dentry, dentry->d_name.len, dentry->d_name.name);
635
636 ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
637 if (ino == NULL)
638 return -ENOSPC;
639
640 inode = autofs4_get_inode(dir->i_sb, ino);
641 d_instantiate(dentry, inode);
642
643 if (dir == dir->i_sb->s_root->d_inode)
644 dentry->d_op = &autofs4_root_dentry_operations;
645 else
646 dentry->d_op = &autofs4_dentry_operations;
647
648 dentry->d_fsdata = ino;
649 ino->dentry = dget(dentry);
650 ino->inode = inode;
651 dir->i_nlink++;
652 dir->i_mtime = CURRENT_TIME;
653
654 return 0;
655}
656
657/* Get/set timeout ioctl() operation */
658static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
659 unsigned long __user *p)
660{
661 int rv;
662 unsigned long ntimeout;
663
664 if ( (rv = get_user(ntimeout, p)) ||
665 (rv = put_user(sbi->exp_timeout/HZ, p)) )
666 return rv;
667
668 if ( ntimeout > ULONG_MAX/HZ )
669 sbi->exp_timeout = 0;
670 else
671 sbi->exp_timeout = ntimeout * HZ;
672
673 return 0;
674}
675
676/* Return protocol version */
677static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
678{
679 return put_user(sbi->version, p);
680}
681
682/* Return protocol sub version */
683static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p)
684{
685 return put_user(sbi->sub_version, p);
686}
687
688/*
689 * Tells the daemon whether we need to reghost or not. Also, clears
690 * the reghost_needed flag.
691 */
692static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p)
693{
694 int status;
695
696 DPRINTK("returning %d", sbi->needs_reghost);
697
698 status = put_user(sbi->needs_reghost, p);
699 if ( status )
700 return status;
701
702 sbi->needs_reghost = 0;
703 return 0;
704}
705
706/*
707 * Enable / Disable reghosting ioctl() operation
708 */
709static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p)
710{
711 int status;
712 int val;
713
714 status = get_user(val, p);
715
716 DPRINTK("reghost = %d", val);
717
718 if (status)
719 return status;
720
721 /* turn on/off reghosting, with the val */
722 sbi->reghost_enabled = val;
723 return 0;
724}
725
726/*
727* Tells the daemon whether it can umount the autofs mount.
728*/
729static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
730{
731 int status = 0;
732
733 if (may_umount(mnt) == 0)
734 status = 1;
735
736 DPRINTK("returning %d", status);
737
738 status = put_user(status, p);
739
740 return status;
741}
742
743/* Identify autofs4_dentries - this is so we can tell if there's
744 an extra dentry refcount or not. We only hold a refcount on the
745 dentry if its non-negative (ie, d_inode != NULL)
746*/
747int is_autofs4_dentry(struct dentry *dentry)
748{
749 return dentry && dentry->d_inode &&
750 (dentry->d_op == &autofs4_root_dentry_operations ||
751 dentry->d_op == &autofs4_dentry_operations) &&
752 dentry->d_fsdata != NULL;
753}
754
755/*
756 * ioctl()'s on the root directory is the chief method for the daemon to
757 * generate kernel reactions
758 */
759static int autofs4_root_ioctl(struct inode *inode, struct file *filp,
760 unsigned int cmd, unsigned long arg)
761{
762 struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
763 void __user *p = (void __user *)arg;
764
765 DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
766 cmd,arg,sbi,process_group(current));
767
768 if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
769 _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT )
770 return -ENOTTY;
771
772 if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
773 return -EPERM;
774
775 switch(cmd) {
776 case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */
777 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
778 case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */
779 return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
780 case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
781 autofs4_catatonic_mode(sbi);
782 return 0;
783 case AUTOFS_IOC_PROTOVER: /* Get protocol version */
784 return autofs4_get_protover(sbi, p);
785 case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
786 return autofs4_get_protosubver(sbi, p);
787 case AUTOFS_IOC_SETTIMEOUT:
788 return autofs4_get_set_timeout(sbi, p);
789
790 case AUTOFS_IOC_TOGGLEREGHOST:
791 return autofs4_toggle_reghost(sbi, p);
792 case AUTOFS_IOC_ASKREGHOST:
793 return autofs4_ask_reghost(sbi, p);
794
795 case AUTOFS_IOC_ASKUMOUNT:
796 return autofs4_ask_umount(filp->f_vfsmnt, p);
797
798 /* return a single thing to expire */
799 case AUTOFS_IOC_EXPIRE:
800 return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi, p);
801 /* same as above, but can send multiple expires through pipe */
802 case AUTOFS_IOC_EXPIRE_MULTI:
803 return autofs4_expire_multi(inode->i_sb,filp->f_vfsmnt,sbi, p);
804
805 default:
806 return -ENOSYS;
807 }
808}
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-17 23:07:39 -0500