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 | 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 LT |
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, | |
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 | ||
1da177e4 LT |
66 | struct inode_operations autofs4_dir_inode_operations = { |
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 | { | |
77 | struct autofs_sb_info *sbi = autofs4_sbi(file->f_dentry->d_sb); | |
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 | { | |
98 | struct dentry *dentry = file->f_dentry; | |
99 | struct vfsmount *mnt = file->f_vfsmnt; | |
100 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b | 101 | struct dentry *cursor; |
1da177e4 LT |
102 | int status; |
103 | ||
f360ce3b IK |
104 | status = dcache_dir_open(inode, file); |
105 | if (status) | |
106 | goto out; | |
107 | ||
108 | cursor = file->private_data; | |
109 | cursor->d_fsdata = NULL; | |
110 | ||
1da177e4 LT |
111 | DPRINTK("file=%p dentry=%p %.*s", |
112 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
113 | ||
114 | if (autofs4_oz_mode(sbi)) | |
115 | goto out; | |
116 | ||
117 | if (autofs4_ispending(dentry)) { | |
118 | DPRINTK("dentry busy"); | |
f360ce3b IK |
119 | dcache_dir_close(inode, file); |
120 | status = -EBUSY; | |
121 | goto out; | |
1da177e4 LT |
122 | } |
123 | ||
f360ce3b | 124 | status = -ENOENT; |
1da177e4 LT |
125 | if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) { |
126 | struct nameidata nd; | |
f360ce3b | 127 | int empty, ret; |
1da177e4 LT |
128 | |
129 | /* In case there are stale directory dentrys from a failed mount */ | |
130 | spin_lock(&dcache_lock); | |
131 | empty = list_empty(&dentry->d_subdirs); | |
132 | spin_unlock(&dcache_lock); | |
133 | ||
134 | if (!empty) | |
135 | d_invalidate(dentry); | |
136 | ||
137 | nd.flags = LOOKUP_DIRECTORY; | |
f360ce3b | 138 | ret = (dentry->d_op->d_revalidate)(dentry, &nd); |
1da177e4 | 139 | |
f360ce3b IK |
140 | if (!ret) { |
141 | dcache_dir_close(inode, file); | |
142 | goto out; | |
143 | } | |
1da177e4 LT |
144 | } |
145 | ||
146 | if (d_mountpoint(dentry)) { | |
147 | struct file *fp = NULL; | |
148 | struct vfsmount *fp_mnt = mntget(mnt); | |
149 | struct dentry *fp_dentry = dget(dentry); | |
150 | ||
9b1e3afd IK |
151 | if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) { |
152 | dput(fp_dentry); | |
153 | mntput(fp_mnt); | |
f360ce3b IK |
154 | dcache_dir_close(inode, file); |
155 | goto out; | |
9b1e3afd | 156 | } |
1da177e4 LT |
157 | |
158 | fp = dentry_open(fp_dentry, fp_mnt, file->f_flags); | |
159 | status = PTR_ERR(fp); | |
160 | if (IS_ERR(fp)) { | |
f360ce3b IK |
161 | dcache_dir_close(inode, file); |
162 | goto out; | |
1da177e4 | 163 | } |
f360ce3b | 164 | cursor->d_fsdata = fp; |
1da177e4 | 165 | } |
1da177e4 | 166 | return 0; |
f360ce3b IK |
167 | out: |
168 | return status; | |
1da177e4 LT |
169 | } |
170 | ||
171 | static int autofs4_dir_close(struct inode *inode, struct file *file) | |
172 | { | |
173 | struct dentry *dentry = file->f_dentry; | |
174 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b IK |
175 | struct dentry *cursor = file->private_data; |
176 | int status = 0; | |
1da177e4 LT |
177 | |
178 | DPRINTK("file=%p dentry=%p %.*s", | |
179 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
180 | ||
181 | if (autofs4_oz_mode(sbi)) | |
182 | goto out; | |
183 | ||
184 | if (autofs4_ispending(dentry)) { | |
185 | DPRINTK("dentry busy"); | |
f360ce3b IK |
186 | status = -EBUSY; |
187 | goto out; | |
1da177e4 LT |
188 | } |
189 | ||
190 | if (d_mountpoint(dentry)) { | |
f360ce3b IK |
191 | struct file *fp = cursor->d_fsdata; |
192 | if (!fp) { | |
193 | status = -ENOENT; | |
194 | goto out; | |
195 | } | |
1da177e4 | 196 | filp_close(fp, current->files); |
1da177e4 LT |
197 | } |
198 | out: | |
f360ce3b IK |
199 | dcache_dir_close(inode, file); |
200 | return status; | |
1da177e4 LT |
201 | } |
202 | ||
203 | static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir) | |
204 | { | |
205 | struct dentry *dentry = file->f_dentry; | |
206 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
f360ce3b | 207 | struct dentry *cursor = file->private_data; |
1da177e4 LT |
208 | int status; |
209 | ||
210 | DPRINTK("file=%p dentry=%p %.*s", | |
211 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
212 | ||
213 | if (autofs4_oz_mode(sbi)) | |
214 | goto out; | |
215 | ||
216 | if (autofs4_ispending(dentry)) { | |
217 | DPRINTK("dentry busy"); | |
218 | return -EBUSY; | |
219 | } | |
220 | ||
221 | if (d_mountpoint(dentry)) { | |
f360ce3b | 222 | struct file *fp = cursor->d_fsdata; |
1da177e4 LT |
223 | |
224 | if (!fp) | |
225 | return -ENOENT; | |
226 | ||
227 | if (!fp->f_op || !fp->f_op->readdir) | |
228 | goto out; | |
229 | ||
230 | status = vfs_readdir(fp, filldir, dirent); | |
231 | file->f_pos = fp->f_pos; | |
232 | if (status) | |
233 | autofs4_copy_atime(file, fp); | |
234 | return status; | |
235 | } | |
236 | out: | |
f360ce3b | 237 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
238 | } |
239 | ||
862b110f | 240 | static int try_to_fill_dentry(struct dentry *dentry, int flags) |
1da177e4 | 241 | { |
862b110f | 242 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
718c604a | 243 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
1da177e4 LT |
244 | int status = 0; |
245 | ||
246 | /* Block on any pending expiry here; invalidate the dentry | |
247 | when expiration is done to trigger mount request with a new | |
248 | dentry */ | |
718c604a | 249 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { |
1da177e4 LT |
250 | DPRINTK("waiting for expire %p name=%.*s", |
251 | dentry, dentry->d_name.len, dentry->d_name.name); | |
252 | ||
253 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
718c604a | 254 | |
1da177e4 | 255 | DPRINTK("expire done status=%d", status); |
718c604a | 256 | |
1684b2bb IK |
257 | /* |
258 | * If the directory still exists the mount request must | |
259 | * continue otherwise it can't be followed at the right | |
260 | * time during the walk. | |
261 | */ | |
262 | status = d_invalidate(dentry); | |
263 | if (status != -EBUSY) | |
34ca959c | 264 | return -ENOENT; |
1da177e4 LT |
265 | } |
266 | ||
267 | DPRINTK("dentry=%p %.*s ino=%p", | |
268 | dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); | |
269 | ||
718c604a IK |
270 | /* |
271 | * Wait for a pending mount, triggering one if there | |
272 | * isn't one already | |
273 | */ | |
1da177e4 LT |
274 | if (dentry->d_inode == NULL) { |
275 | DPRINTK("waiting for mount name=%.*s", | |
276 | dentry->d_name.len, dentry->d_name.name); | |
277 | ||
278 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
718c604a | 279 | |
1da177e4 LT |
280 | DPRINTK("mount done status=%d", status); |
281 | ||
282 | if (status && dentry->d_inode) | |
34ca959c | 283 | return status; /* Try to get the kernel to invalidate this dentry */ |
718c604a | 284 | |
1da177e4 LT |
285 | /* Turn this into a real negative dentry? */ |
286 | if (status == -ENOENT) { | |
1da177e4 LT |
287 | spin_lock(&dentry->d_lock); |
288 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
289 | spin_unlock(&dentry->d_lock); | |
34ca959c | 290 | return status; |
1da177e4 LT |
291 | } else if (status) { |
292 | /* Return a negative dentry, but leave it "pending" */ | |
34ca959c | 293 | return status; |
1da177e4 LT |
294 | } |
295 | /* Trigger mount for path component or follow link */ | |
296 | } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) || | |
297 | current->link_count) { | |
298 | DPRINTK("waiting for mount name=%.*s", | |
299 | dentry->d_name.len, dentry->d_name.name); | |
300 | ||
301 | spin_lock(&dentry->d_lock); | |
302 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
303 | spin_unlock(&dentry->d_lock); | |
304 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
305 | ||
306 | DPRINTK("mount done status=%d", status); | |
307 | ||
308 | if (status) { | |
309 | spin_lock(&dentry->d_lock); | |
310 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
311 | spin_unlock(&dentry->d_lock); | |
34ca959c | 312 | return status; |
1da177e4 LT |
313 | } |
314 | } | |
315 | ||
e0a7aae9 IK |
316 | /* Initialize expiry counter after successful mount */ |
317 | if (ino) | |
318 | ino->last_used = jiffies; | |
319 | ||
1da177e4 LT |
320 | spin_lock(&dentry->d_lock); |
321 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
322 | spin_unlock(&dentry->d_lock); | |
34ca959c IK |
323 | return status; |
324 | } | |
325 | ||
326 | /* For autofs direct mounts the follow link triggers the mount */ | |
327 | static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) | |
328 | { | |
329 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
330 | int oz_mode = autofs4_oz_mode(sbi); | |
331 | unsigned int lookup_type; | |
332 | int status; | |
333 | ||
334 | DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d", | |
335 | dentry, dentry->d_name.len, dentry->d_name.name, oz_mode, | |
336 | nd->flags); | |
337 | ||
338 | /* If it's our master or we shouldn't trigger a mount we're done */ | |
339 | lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY); | |
340 | if (oz_mode || !lookup_type) | |
341 | goto done; | |
342 | ||
871f9434 IK |
343 | /* |
344 | * If a request is pending wait for it. | |
345 | * If it's a mount then it won't be expired till at least | |
346 | * a liitle later and if it's an expire then we might need | |
347 | * to mount it again. | |
348 | */ | |
349 | if (autofs4_ispending(dentry)) { | |
350 | DPRINTK("waiting for active request %p name=%.*s", | |
351 | dentry, dentry->d_name.len, dentry->d_name.name); | |
352 | ||
353 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
354 | ||
355 | DPRINTK("request done status=%d", status); | |
356 | } | |
34ca959c | 357 | |
871f9434 IK |
358 | /* |
359 | * If the dentry contains directories then it is an | |
360 | * autofs multi-mount with no root mount offset. So | |
361 | * don't try to mount it again. | |
362 | */ | |
363 | spin_lock(&dcache_lock); | |
364 | if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { | |
365 | spin_unlock(&dcache_lock); | |
366 | ||
367 | status = try_to_fill_dentry(dentry, 0); | |
368 | if (status) | |
369 | goto out_error; | |
370 | ||
371 | /* | |
372 | * The mount succeeded but if there is no root mount | |
373 | * it must be an autofs multi-mount with no root offset | |
374 | * so we don't need to follow the mount. | |
375 | */ | |
376 | if (d_mountpoint(dentry)) { | |
377 | if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) { | |
378 | status = -ENOENT; | |
379 | goto out_error; | |
380 | } | |
381 | } | |
382 | ||
383 | goto done; | |
34ca959c | 384 | } |
871f9434 | 385 | spin_unlock(&dcache_lock); |
34ca959c IK |
386 | |
387 | done: | |
388 | return NULL; | |
389 | ||
390 | out_error: | |
391 | path_release(nd); | |
392 | return ERR_PTR(status); | |
1da177e4 LT |
393 | } |
394 | ||
395 | /* | |
396 | * Revalidate is called on every cache lookup. Some of those | |
397 | * cache lookups may actually happen while the dentry is not | |
398 | * yet completely filled in, and revalidate has to delay such | |
399 | * lookups.. | |
400 | */ | |
718c604a | 401 | static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 402 | { |
718c604a | 403 | struct inode *dir = dentry->d_parent->d_inode; |
1da177e4 LT |
404 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
405 | int oz_mode = autofs4_oz_mode(sbi); | |
406 | int flags = nd ? nd->flags : 0; | |
34ca959c | 407 | int status = 0; |
1da177e4 LT |
408 | |
409 | /* Pending dentry */ | |
410 | if (autofs4_ispending(dentry)) { | |
411 | if (!oz_mode) | |
862b110f | 412 | status = try_to_fill_dentry(dentry, flags); |
34ca959c | 413 | return !status; |
1da177e4 LT |
414 | } |
415 | ||
416 | /* Negative dentry.. invalidate if "old" */ | |
417 | if (dentry->d_inode == NULL) | |
2d753e62 | 418 | return 0; |
1da177e4 LT |
419 | |
420 | /* Check for a non-mountpoint directory with no contents */ | |
421 | spin_lock(&dcache_lock); | |
422 | if (S_ISDIR(dentry->d_inode->i_mode) && | |
423 | !d_mountpoint(dentry) && | |
90a59c7c | 424 | __simple_empty(dentry)) { |
1da177e4 LT |
425 | DPRINTK("dentry=%p %.*s, emptydir", |
426 | dentry, dentry->d_name.len, dentry->d_name.name); | |
427 | spin_unlock(&dcache_lock); | |
428 | if (!oz_mode) | |
862b110f | 429 | status = try_to_fill_dentry(dentry, flags); |
34ca959c | 430 | return !status; |
1da177e4 LT |
431 | } |
432 | spin_unlock(&dcache_lock); | |
433 | ||
1da177e4 LT |
434 | return 1; |
435 | } | |
436 | ||
34ca959c | 437 | void autofs4_dentry_release(struct dentry *de) |
1da177e4 LT |
438 | { |
439 | struct autofs_info *inf; | |
440 | ||
441 | DPRINTK("releasing %p", de); | |
442 | ||
443 | inf = autofs4_dentry_ino(de); | |
444 | de->d_fsdata = NULL; | |
445 | ||
446 | if (inf) { | |
447 | inf->dentry = NULL; | |
448 | inf->inode = NULL; | |
449 | ||
450 | autofs4_free_ino(inf); | |
451 | } | |
452 | } | |
453 | ||
454 | /* For dentries of directories in the root dir */ | |
455 | static struct dentry_operations autofs4_root_dentry_operations = { | |
456 | .d_revalidate = autofs4_revalidate, | |
457 | .d_release = autofs4_dentry_release, | |
458 | }; | |
459 | ||
460 | /* For other dentries */ | |
461 | static struct dentry_operations autofs4_dentry_operations = { | |
462 | .d_revalidate = autofs4_revalidate, | |
463 | .d_release = autofs4_dentry_release, | |
464 | }; | |
465 | ||
466 | /* Lookups in the root directory */ | |
467 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
468 | { | |
469 | struct autofs_sb_info *sbi; | |
470 | int oz_mode; | |
471 | ||
472 | DPRINTK("name = %.*s", | |
473 | dentry->d_name.len, dentry->d_name.name); | |
474 | ||
718c604a | 475 | /* File name too long to exist */ |
1da177e4 | 476 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 477 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
478 | |
479 | sbi = autofs4_sbi(dir->i_sb); | |
1da177e4 | 480 | oz_mode = autofs4_oz_mode(sbi); |
718c604a | 481 | |
1da177e4 LT |
482 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
483 | current->pid, process_group(current), sbi->catatonic, oz_mode); | |
484 | ||
485 | /* | |
486 | * Mark the dentry incomplete, but add it. This is needed so | |
487 | * that the VFS layer knows about the dentry, and we can count | |
488 | * on catching any lookups through the revalidate. | |
489 | * | |
490 | * Let all the hard work be done by the revalidate function that | |
491 | * needs to be able to do this anyway.. | |
492 | * | |
493 | * We need to do this before we release the directory semaphore. | |
494 | */ | |
495 | dentry->d_op = &autofs4_root_dentry_operations; | |
496 | ||
497 | if (!oz_mode) { | |
498 | spin_lock(&dentry->d_lock); | |
499 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
500 | spin_unlock(&dentry->d_lock); | |
501 | } | |
502 | dentry->d_fsdata = NULL; | |
503 | d_add(dentry, NULL); | |
504 | ||
505 | if (dentry->d_op && dentry->d_op->d_revalidate) { | |
1b1dcc1b | 506 | mutex_unlock(&dir->i_mutex); |
1da177e4 | 507 | (dentry->d_op->d_revalidate)(dentry, nd); |
1b1dcc1b | 508 | mutex_lock(&dir->i_mutex); |
1da177e4 LT |
509 | } |
510 | ||
511 | /* | |
512 | * If we are still pending, check if we had to handle | |
513 | * a signal. If so we can force a restart.. | |
514 | */ | |
515 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { | |
516 | /* See if we were interrupted */ | |
517 | if (signal_pending(current)) { | |
518 | sigset_t *sigset = ¤t->pending.signal; | |
519 | if (sigismember (sigset, SIGKILL) || | |
520 | sigismember (sigset, SIGQUIT) || | |
521 | sigismember (sigset, SIGINT)) { | |
522 | return ERR_PTR(-ERESTARTNOINTR); | |
523 | } | |
524 | } | |
525 | } | |
526 | ||
527 | /* | |
528 | * If this dentry is unhashed, then we shouldn't honour this | |
529 | * lookup even if the dentry is positive. Returning ENOENT here | |
530 | * doesn't do the right thing for all system calls, but it should | |
531 | * be OK for the operations we permit from an autofs. | |
532 | */ | |
718c604a | 533 | if (dentry->d_inode && d_unhashed(dentry)) |
1da177e4 LT |
534 | return ERR_PTR(-ENOENT); |
535 | ||
536 | return NULL; | |
537 | } | |
538 | ||
539 | static int autofs4_dir_symlink(struct inode *dir, | |
540 | struct dentry *dentry, | |
541 | const char *symname) | |
542 | { | |
543 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
544 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 545 | struct autofs_info *p_ino; |
1da177e4 LT |
546 | struct inode *inode; |
547 | char *cp; | |
548 | ||
549 | DPRINTK("%s <- %.*s", symname, | |
550 | dentry->d_name.len, dentry->d_name.name); | |
551 | ||
552 | if (!autofs4_oz_mode(sbi)) | |
553 | return -EACCES; | |
554 | ||
555 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
556 | if (ino == NULL) | |
557 | return -ENOSPC; | |
558 | ||
559 | ino->size = strlen(symname); | |
560 | ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL); | |
561 | ||
562 | if (cp == NULL) { | |
563 | kfree(ino); | |
564 | return -ENOSPC; | |
565 | } | |
566 | ||
567 | strcpy(cp, symname); | |
568 | ||
569 | inode = autofs4_get_inode(dir->i_sb, ino); | |
570 | d_instantiate(dentry, inode); | |
571 | ||
572 | if (dir == dir->i_sb->s_root->d_inode) | |
573 | dentry->d_op = &autofs4_root_dentry_operations; | |
574 | else | |
575 | dentry->d_op = &autofs4_dentry_operations; | |
576 | ||
577 | dentry->d_fsdata = ino; | |
578 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
579 | atomic_inc(&ino->count); |
580 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
581 | if (p_ino && dentry->d_parent != dentry) | |
582 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
583 | ino->inode = inode; |
584 | ||
585 | dir->i_mtime = CURRENT_TIME; | |
586 | ||
587 | return 0; | |
588 | } | |
589 | ||
590 | /* | |
591 | * NOTE! | |
592 | * | |
593 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
594 | * that the file no longer exists. However, doing that means that the | |
595 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
596 | * this, because since the unlink is probably the result of an expire. | |
597 | * We simply d_drop it, which allows the dentry lookup to remount it | |
598 | * if necessary. | |
599 | * | |
600 | * If a process is blocked on the dentry waiting for the expire to finish, | |
601 | * it will invalidate the dentry and try to mount with a new one. | |
602 | * | |
603 | * Also see autofs4_dir_rmdir().. | |
604 | */ | |
605 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
606 | { | |
607 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
608 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 609 | struct autofs_info *p_ino; |
1da177e4 LT |
610 | |
611 | /* This allows root to remove symlinks */ | |
612 | if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) | |
613 | return -EACCES; | |
614 | ||
1aff3c8b IK |
615 | if (atomic_dec_and_test(&ino->count)) { |
616 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
617 | if (p_ino && dentry->d_parent != dentry) | |
618 | atomic_dec(&p_ino->count); | |
619 | } | |
1da177e4 LT |
620 | dput(ino->dentry); |
621 | ||
622 | dentry->d_inode->i_size = 0; | |
623 | dentry->d_inode->i_nlink = 0; | |
624 | ||
625 | dir->i_mtime = CURRENT_TIME; | |
626 | ||
627 | d_drop(dentry); | |
628 | ||
629 | return 0; | |
630 | } | |
631 | ||
632 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
633 | { | |
634 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
635 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 636 | struct autofs_info *p_ino; |
1da177e4 LT |
637 | |
638 | if (!autofs4_oz_mode(sbi)) | |
639 | return -EACCES; | |
640 | ||
641 | spin_lock(&dcache_lock); | |
642 | if (!list_empty(&dentry->d_subdirs)) { | |
643 | spin_unlock(&dcache_lock); | |
644 | return -ENOTEMPTY; | |
645 | } | |
646 | spin_lock(&dentry->d_lock); | |
647 | __d_drop(dentry); | |
648 | spin_unlock(&dentry->d_lock); | |
649 | spin_unlock(&dcache_lock); | |
650 | ||
1aff3c8b IK |
651 | if (atomic_dec_and_test(&ino->count)) { |
652 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
653 | if (p_ino && dentry->d_parent != dentry) | |
654 | atomic_dec(&p_ino->count); | |
655 | } | |
1da177e4 | 656 | dput(ino->dentry); |
1da177e4 LT |
657 | dentry->d_inode->i_size = 0; |
658 | dentry->d_inode->i_nlink = 0; | |
659 | ||
660 | if (dir->i_nlink) | |
661 | dir->i_nlink--; | |
662 | ||
663 | return 0; | |
664 | } | |
665 | ||
666 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
667 | { | |
668 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
669 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 670 | struct autofs_info *p_ino; |
1da177e4 LT |
671 | struct inode *inode; |
672 | ||
673 | if ( !autofs4_oz_mode(sbi) ) | |
674 | return -EACCES; | |
675 | ||
676 | DPRINTK("dentry %p, creating %.*s", | |
677 | dentry, dentry->d_name.len, dentry->d_name.name); | |
678 | ||
679 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
680 | if (ino == NULL) | |
681 | return -ENOSPC; | |
682 | ||
683 | inode = autofs4_get_inode(dir->i_sb, ino); | |
684 | d_instantiate(dentry, inode); | |
685 | ||
686 | if (dir == dir->i_sb->s_root->d_inode) | |
687 | dentry->d_op = &autofs4_root_dentry_operations; | |
688 | else | |
689 | dentry->d_op = &autofs4_dentry_operations; | |
690 | ||
691 | dentry->d_fsdata = ino; | |
692 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
693 | atomic_inc(&ino->count); |
694 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
695 | if (p_ino && dentry->d_parent != dentry) | |
696 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
697 | ino->inode = inode; |
698 | dir->i_nlink++; | |
699 | dir->i_mtime = CURRENT_TIME; | |
700 | ||
701 | return 0; | |
702 | } | |
703 | ||
704 | /* Get/set timeout ioctl() operation */ | |
705 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, | |
706 | unsigned long __user *p) | |
707 | { | |
708 | int rv; | |
709 | unsigned long ntimeout; | |
710 | ||
711 | if ( (rv = get_user(ntimeout, p)) || | |
712 | (rv = put_user(sbi->exp_timeout/HZ, p)) ) | |
713 | return rv; | |
714 | ||
715 | if ( ntimeout > ULONG_MAX/HZ ) | |
716 | sbi->exp_timeout = 0; | |
717 | else | |
718 | sbi->exp_timeout = ntimeout * HZ; | |
719 | ||
720 | return 0; | |
721 | } | |
722 | ||
723 | /* Return protocol version */ | |
724 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
725 | { | |
726 | return put_user(sbi->version, p); | |
727 | } | |
728 | ||
729 | /* Return protocol sub version */ | |
730 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
731 | { | |
732 | return put_user(sbi->sub_version, p); | |
733 | } | |
734 | ||
735 | /* | |
736 | * Tells the daemon whether we need to reghost or not. Also, clears | |
737 | * the reghost_needed flag. | |
738 | */ | |
739 | static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p) | |
740 | { | |
741 | int status; | |
742 | ||
743 | DPRINTK("returning %d", sbi->needs_reghost); | |
744 | ||
745 | status = put_user(sbi->needs_reghost, p); | |
746 | if ( status ) | |
747 | return status; | |
748 | ||
749 | sbi->needs_reghost = 0; | |
750 | return 0; | |
751 | } | |
752 | ||
753 | /* | |
754 | * Enable / Disable reghosting ioctl() operation | |
755 | */ | |
756 | static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p) | |
757 | { | |
758 | int status; | |
759 | int val; | |
760 | ||
761 | status = get_user(val, p); | |
762 | ||
763 | DPRINTK("reghost = %d", val); | |
764 | ||
765 | if (status) | |
766 | return status; | |
767 | ||
768 | /* turn on/off reghosting, with the val */ | |
769 | sbi->reghost_enabled = val; | |
770 | return 0; | |
771 | } | |
772 | ||
773 | /* | |
774 | * Tells the daemon whether it can umount the autofs mount. | |
775 | */ | |
776 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
777 | { | |
778 | int status = 0; | |
779 | ||
e3474a8e | 780 | if (may_umount(mnt)) |
1da177e4 LT |
781 | status = 1; |
782 | ||
783 | DPRINTK("returning %d", status); | |
784 | ||
785 | status = put_user(status, p); | |
786 | ||
787 | return status; | |
788 | } | |
789 | ||
790 | /* Identify autofs4_dentries - this is so we can tell if there's | |
791 | an extra dentry refcount or not. We only hold a refcount on the | |
792 | dentry if its non-negative (ie, d_inode != NULL) | |
793 | */ | |
794 | int is_autofs4_dentry(struct dentry *dentry) | |
795 | { | |
796 | return dentry && dentry->d_inode && | |
797 | (dentry->d_op == &autofs4_root_dentry_operations || | |
798 | dentry->d_op == &autofs4_dentry_operations) && | |
799 | dentry->d_fsdata != NULL; | |
800 | } | |
801 | ||
802 | /* | |
803 | * ioctl()'s on the root directory is the chief method for the daemon to | |
804 | * generate kernel reactions | |
805 | */ | |
806 | static int autofs4_root_ioctl(struct inode *inode, struct file *filp, | |
807 | unsigned int cmd, unsigned long arg) | |
808 | { | |
809 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
810 | void __user *p = (void __user *)arg; | |
811 | ||
812 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
813 | cmd,arg,sbi,process_group(current)); | |
814 | ||
815 | if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || | |
816 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT ) | |
817 | return -ENOTTY; | |
818 | ||
819 | if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) | |
820 | return -EPERM; | |
821 | ||
822 | switch(cmd) { | |
823 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
824 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
825 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
826 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
827 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
828 | autofs4_catatonic_mode(sbi); | |
829 | return 0; | |
830 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
831 | return autofs4_get_protover(sbi, p); | |
832 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
833 | return autofs4_get_protosubver(sbi, p); | |
834 | case AUTOFS_IOC_SETTIMEOUT: | |
835 | return autofs4_get_set_timeout(sbi, p); | |
836 | ||
837 | case AUTOFS_IOC_TOGGLEREGHOST: | |
838 | return autofs4_toggle_reghost(sbi, p); | |
839 | case AUTOFS_IOC_ASKREGHOST: | |
840 | return autofs4_ask_reghost(sbi, p); | |
841 | ||
842 | case AUTOFS_IOC_ASKUMOUNT: | |
843 | return autofs4_ask_umount(filp->f_vfsmnt, p); | |
844 | ||
845 | /* return a single thing to expire */ | |
846 | case AUTOFS_IOC_EXPIRE: | |
847 | return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi, p); | |
848 | /* same as above, but can send multiple expires through pipe */ | |
849 | case AUTOFS_IOC_EXPIRE_MULTI: | |
850 | return autofs4_expire_multi(inode->i_sb,filp->f_vfsmnt,sbi, p); | |
851 | ||
852 | default: | |
853 | return -ENOSYS; | |
854 | } | |
855 | } |