Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* -*- c -*- --------------------------------------------------------------- * |
2 | * | |
3 | * linux/fs/autofs/root.c | |
4 | * | |
5 | * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved | |
6 | * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> | |
34ca959c | 7 | * Copyright 2001-2006 Ian Kent <raven@themaw.net> |
1da177e4 LT |
8 | * |
9 | * This file is part of the Linux kernel and is made available under | |
10 | * the terms of the GNU General Public License, version 2, or at your | |
11 | * option, any later version, incorporated herein by reference. | |
12 | * | |
13 | * ------------------------------------------------------------------------- */ | |
14 | ||
16f7e0fe | 15 | #include <linux/capability.h> |
1da177e4 LT |
16 | #include <linux/errno.h> |
17 | #include <linux/stat.h> | |
18 | #include <linux/param.h> | |
19 | #include <linux/time.h> | |
1da177e4 LT |
20 | #include "autofs_i.h" |
21 | ||
22 | static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); | |
23 | static int autofs4_dir_unlink(struct inode *,struct dentry *); | |
24 | static int autofs4_dir_rmdir(struct inode *,struct dentry *); | |
25 | static int autofs4_dir_mkdir(struct inode *,struct dentry *,int); | |
26 | static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long); | |
27 | static int autofs4_dir_open(struct inode *inode, struct file *file); | |
28 | static int autofs4_dir_close(struct inode *inode, struct file *file); | |
29 | static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir); | |
30 | static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir); | |
31 | static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *); | |
34ca959c | 32 | static void *autofs4_follow_link(struct dentry *, struct nameidata *); |
1da177e4 | 33 | |
4b6f5d20 | 34 | const struct file_operations autofs4_root_operations = { |
1da177e4 LT |
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 | ||
4b6f5d20 | 42 | const struct file_operations autofs4_dir_operations = { |
1da177e4 LT |
43 | .open = autofs4_dir_open, |
44 | .release = autofs4_dir_close, | |
45 | .read = generic_read_dir, | |
46 | .readdir = autofs4_dir_readdir, | |
47 | }; | |
48 | ||
754661f1 | 49 | const struct inode_operations autofs4_indirect_root_inode_operations = { |
1da177e4 LT |
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 | ||
754661f1 | 57 | const struct inode_operations autofs4_direct_root_inode_operations = { |
34ca959c | 58 | .lookup = autofs4_lookup, |
871f9434 IK |
59 | .unlink = autofs4_dir_unlink, |
60 | .mkdir = autofs4_dir_mkdir, | |
61 | .rmdir = autofs4_dir_rmdir, | |
34ca959c IK |
62 | .follow_link = autofs4_follow_link, |
63 | }; | |
64 | ||
754661f1 | 65 | const struct inode_operations autofs4_dir_inode_operations = { |
1da177e4 LT |
66 | .lookup = autofs4_lookup, |
67 | .unlink = autofs4_dir_unlink, | |
68 | .symlink = autofs4_dir_symlink, | |
69 | .mkdir = autofs4_dir_mkdir, | |
70 | .rmdir = autofs4_dir_rmdir, | |
71 | }; | |
72 | ||
73 | static int autofs4_root_readdir(struct file *file, void *dirent, | |
74 | filldir_t filldir) | |
75 | { | |
a4669ed8 | 76 | struct autofs_sb_info *sbi = autofs4_sbi(file->f_path.dentry->d_sb); |
1da177e4 LT |
77 | int oz_mode = autofs4_oz_mode(sbi); |
78 | ||
79 | DPRINTK("called, filp->f_pos = %lld", file->f_pos); | |
80 | ||
81 | /* | |
82 | * Don't set reghost flag if: | |
83 | * 1) f_pos is larger than zero -- we've already been here. | |
84 | * 2) we haven't even enabled reghosting in the 1st place. | |
85 | * 3) this is the daemon doing a readdir | |
86 | */ | |
87 | if (oz_mode && file->f_pos == 0 && sbi->reghost_enabled) | |
88 | sbi->needs_reghost = 1; | |
89 | ||
90 | DPRINTK("needs_reghost = %d", sbi->needs_reghost); | |
91 | ||
f360ce3b | 92 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
93 | } |
94 | ||
1da177e4 LT |
95 | static int autofs4_dir_open(struct inode *inode, struct file *file) |
96 | { | |
a4669ed8 JJS |
97 | struct dentry *dentry = file->f_path.dentry; |
98 | struct vfsmount *mnt = file->f_path.mnt; | |
1da177e4 | 99 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 100 | struct dentry *cursor; |
1da177e4 LT |
101 | int status; |
102 | ||
f360ce3b IK |
103 | status = dcache_dir_open(inode, file); |
104 | if (status) | |
105 | goto out; | |
106 | ||
107 | cursor = file->private_data; | |
108 | cursor->d_fsdata = NULL; | |
109 | ||
1da177e4 LT |
110 | DPRINTK("file=%p dentry=%p %.*s", |
111 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
112 | ||
113 | if (autofs4_oz_mode(sbi)) | |
114 | goto out; | |
115 | ||
116 | if (autofs4_ispending(dentry)) { | |
117 | DPRINTK("dentry busy"); | |
f360ce3b IK |
118 | dcache_dir_close(inode, file); |
119 | status = -EBUSY; | |
120 | goto out; | |
1da177e4 LT |
121 | } |
122 | ||
f360ce3b | 123 | status = -ENOENT; |
1da177e4 LT |
124 | if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) { |
125 | struct nameidata nd; | |
f360ce3b | 126 | int empty, ret; |
1da177e4 LT |
127 | |
128 | /* In case there are stale directory dentrys from a failed mount */ | |
129 | spin_lock(&dcache_lock); | |
130 | empty = list_empty(&dentry->d_subdirs); | |
131 | spin_unlock(&dcache_lock); | |
132 | ||
133 | if (!empty) | |
134 | d_invalidate(dentry); | |
135 | ||
136 | nd.flags = LOOKUP_DIRECTORY; | |
f360ce3b | 137 | ret = (dentry->d_op->d_revalidate)(dentry, &nd); |
1da177e4 | 138 | |
bcdc5e01 IK |
139 | if (ret <= 0) { |
140 | if (ret < 0) | |
141 | status = ret; | |
f360ce3b IK |
142 | dcache_dir_close(inode, file); |
143 | goto out; | |
144 | } | |
1da177e4 LT |
145 | } |
146 | ||
147 | if (d_mountpoint(dentry)) { | |
148 | struct file *fp = NULL; | |
149 | struct vfsmount *fp_mnt = mntget(mnt); | |
150 | struct dentry *fp_dentry = dget(dentry); | |
151 | ||
9b1e3afd IK |
152 | if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) { |
153 | dput(fp_dentry); | |
154 | mntput(fp_mnt); | |
f360ce3b IK |
155 | dcache_dir_close(inode, file); |
156 | goto out; | |
9b1e3afd | 157 | } |
1da177e4 LT |
158 | |
159 | fp = dentry_open(fp_dentry, fp_mnt, file->f_flags); | |
160 | status = PTR_ERR(fp); | |
161 | if (IS_ERR(fp)) { | |
f360ce3b IK |
162 | dcache_dir_close(inode, file); |
163 | goto out; | |
1da177e4 | 164 | } |
f360ce3b | 165 | cursor->d_fsdata = fp; |
1da177e4 | 166 | } |
1da177e4 | 167 | return 0; |
f360ce3b IK |
168 | out: |
169 | return status; | |
1da177e4 LT |
170 | } |
171 | ||
172 | static int autofs4_dir_close(struct inode *inode, struct file *file) | |
173 | { | |
a4669ed8 | 174 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 175 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b IK |
176 | struct dentry *cursor = file->private_data; |
177 | int status = 0; | |
1da177e4 LT |
178 | |
179 | DPRINTK("file=%p dentry=%p %.*s", | |
180 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
181 | ||
182 | if (autofs4_oz_mode(sbi)) | |
183 | goto out; | |
184 | ||
185 | if (autofs4_ispending(dentry)) { | |
186 | DPRINTK("dentry busy"); | |
f360ce3b IK |
187 | status = -EBUSY; |
188 | goto out; | |
1da177e4 LT |
189 | } |
190 | ||
191 | if (d_mountpoint(dentry)) { | |
f360ce3b IK |
192 | struct file *fp = cursor->d_fsdata; |
193 | if (!fp) { | |
194 | status = -ENOENT; | |
195 | goto out; | |
196 | } | |
1da177e4 | 197 | filp_close(fp, current->files); |
1da177e4 LT |
198 | } |
199 | out: | |
f360ce3b IK |
200 | dcache_dir_close(inode, file); |
201 | return status; | |
1da177e4 LT |
202 | } |
203 | ||
204 | static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir) | |
205 | { | |
a4669ed8 | 206 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 207 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 208 | struct dentry *cursor = file->private_data; |
1da177e4 LT |
209 | int status; |
210 | ||
211 | DPRINTK("file=%p dentry=%p %.*s", | |
212 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
213 | ||
214 | if (autofs4_oz_mode(sbi)) | |
215 | goto out; | |
216 | ||
217 | if (autofs4_ispending(dentry)) { | |
218 | DPRINTK("dentry busy"); | |
219 | return -EBUSY; | |
220 | } | |
221 | ||
222 | if (d_mountpoint(dentry)) { | |
f360ce3b | 223 | struct file *fp = cursor->d_fsdata; |
1da177e4 LT |
224 | |
225 | if (!fp) | |
226 | return -ENOENT; | |
227 | ||
228 | if (!fp->f_op || !fp->f_op->readdir) | |
229 | goto out; | |
230 | ||
231 | status = vfs_readdir(fp, filldir, dirent); | |
232 | file->f_pos = fp->f_pos; | |
233 | if (status) | |
234 | autofs4_copy_atime(file, fp); | |
235 | return status; | |
236 | } | |
237 | out: | |
f360ce3b | 238 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
239 | } |
240 | ||
862b110f | 241 | static int try_to_fill_dentry(struct dentry *dentry, int flags) |
1da177e4 | 242 | { |
862b110f | 243 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
718c604a | 244 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
1da177e4 LT |
245 | int status = 0; |
246 | ||
247 | /* Block on any pending expiry here; invalidate the dentry | |
248 | when expiration is done to trigger mount request with a new | |
249 | dentry */ | |
718c604a | 250 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { |
1da177e4 LT |
251 | DPRINTK("waiting for expire %p name=%.*s", |
252 | dentry, dentry->d_name.len, dentry->d_name.name); | |
253 | ||
254 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
718c604a | 255 | |
1da177e4 | 256 | DPRINTK("expire done status=%d", status); |
718c604a | 257 | |
1684b2bb IK |
258 | /* |
259 | * If the directory still exists the mount request must | |
260 | * continue otherwise it can't be followed at the right | |
261 | * time during the walk. | |
262 | */ | |
263 | status = d_invalidate(dentry); | |
264 | if (status != -EBUSY) | |
f50b6f86 | 265 | return -EAGAIN; |
1da177e4 LT |
266 | } |
267 | ||
268 | DPRINTK("dentry=%p %.*s ino=%p", | |
269 | dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); | |
270 | ||
718c604a IK |
271 | /* |
272 | * Wait for a pending mount, triggering one if there | |
273 | * isn't one already | |
274 | */ | |
1da177e4 LT |
275 | if (dentry->d_inode == NULL) { |
276 | DPRINTK("waiting for mount name=%.*s", | |
277 | dentry->d_name.len, dentry->d_name.name); | |
278 | ||
279 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
718c604a | 280 | |
1da177e4 LT |
281 | DPRINTK("mount done status=%d", status); |
282 | ||
1da177e4 LT |
283 | /* Turn this into a real negative dentry? */ |
284 | if (status == -ENOENT) { | |
1da177e4 LT |
285 | spin_lock(&dentry->d_lock); |
286 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
287 | spin_unlock(&dentry->d_lock); | |
34ca959c | 288 | return status; |
1da177e4 LT |
289 | } else if (status) { |
290 | /* Return a negative dentry, but leave it "pending" */ | |
34ca959c | 291 | return status; |
1da177e4 LT |
292 | } |
293 | /* Trigger mount for path component or follow link */ | |
294 | } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) || | |
295 | current->link_count) { | |
296 | DPRINTK("waiting for mount name=%.*s", | |
297 | dentry->d_name.len, dentry->d_name.name); | |
298 | ||
299 | spin_lock(&dentry->d_lock); | |
300 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
301 | spin_unlock(&dentry->d_lock); | |
302 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
303 | ||
304 | DPRINTK("mount done status=%d", status); | |
305 | ||
306 | if (status) { | |
307 | spin_lock(&dentry->d_lock); | |
308 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
309 | spin_unlock(&dentry->d_lock); | |
34ca959c | 310 | return status; |
1da177e4 LT |
311 | } |
312 | } | |
313 | ||
e0a7aae9 IK |
314 | /* Initialize expiry counter after successful mount */ |
315 | if (ino) | |
316 | ino->last_used = jiffies; | |
317 | ||
1da177e4 LT |
318 | spin_lock(&dentry->d_lock); |
319 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
320 | spin_unlock(&dentry->d_lock); | |
34ca959c IK |
321 | return status; |
322 | } | |
323 | ||
324 | /* For autofs direct mounts the follow link triggers the mount */ | |
325 | static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) | |
326 | { | |
327 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
a5370553 | 328 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
34ca959c IK |
329 | int oz_mode = autofs4_oz_mode(sbi); |
330 | unsigned int lookup_type; | |
331 | int status; | |
332 | ||
333 | DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d", | |
334 | dentry, dentry->d_name.len, dentry->d_name.name, oz_mode, | |
335 | nd->flags); | |
336 | ||
337 | /* If it's our master or we shouldn't trigger a mount we're done */ | |
338 | lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY); | |
339 | if (oz_mode || !lookup_type) | |
340 | goto done; | |
341 | ||
a5370553 IK |
342 | /* If an expire request is pending wait for it. */ |
343 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { | |
871f9434 IK |
344 | DPRINTK("waiting for active request %p name=%.*s", |
345 | dentry, dentry->d_name.len, dentry->d_name.name); | |
346 | ||
347 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
348 | ||
349 | DPRINTK("request done status=%d", status); | |
350 | } | |
34ca959c | 351 | |
871f9434 IK |
352 | /* |
353 | * If the dentry contains directories then it is an | |
354 | * autofs multi-mount with no root mount offset. So | |
355 | * don't try to mount it again. | |
356 | */ | |
357 | spin_lock(&dcache_lock); | |
be3ca7fe | 358 | if (!d_mountpoint(dentry) && __simple_empty(dentry)) { |
871f9434 IK |
359 | spin_unlock(&dcache_lock); |
360 | ||
361 | status = try_to_fill_dentry(dentry, 0); | |
362 | if (status) | |
363 | goto out_error; | |
364 | ||
365 | /* | |
366 | * The mount succeeded but if there is no root mount | |
367 | * it must be an autofs multi-mount with no root offset | |
368 | * so we don't need to follow the mount. | |
369 | */ | |
370 | if (d_mountpoint(dentry)) { | |
4ac91378 JB |
371 | if (!autofs4_follow_mount(&nd->path.mnt, |
372 | &nd->path.dentry)) { | |
871f9434 IK |
373 | status = -ENOENT; |
374 | goto out_error; | |
375 | } | |
376 | } | |
377 | ||
378 | goto done; | |
34ca959c | 379 | } |
871f9434 | 380 | spin_unlock(&dcache_lock); |
34ca959c IK |
381 | |
382 | done: | |
383 | return NULL; | |
384 | ||
385 | out_error: | |
1d957f9b | 386 | path_put(&nd->path); |
34ca959c | 387 | return ERR_PTR(status); |
1da177e4 LT |
388 | } |
389 | ||
390 | /* | |
391 | * Revalidate is called on every cache lookup. Some of those | |
392 | * cache lookups may actually happen while the dentry is not | |
393 | * yet completely filled in, and revalidate has to delay such | |
394 | * lookups.. | |
395 | */ | |
718c604a | 396 | static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) |
1da177e4 | 397 | { |
718c604a | 398 | struct inode *dir = dentry->d_parent->d_inode; |
1da177e4 LT |
399 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); |
400 | int oz_mode = autofs4_oz_mode(sbi); | |
401 | int flags = nd ? nd->flags : 0; | |
bcdc5e01 | 402 | int status = 1; |
1da177e4 LT |
403 | |
404 | /* Pending dentry */ | |
405 | if (autofs4_ispending(dentry)) { | |
bcdc5e01 IK |
406 | /* The daemon never causes a mount to trigger */ |
407 | if (oz_mode) | |
408 | return 1; | |
409 | ||
410 | /* | |
411 | * A zero status is success otherwise we have a | |
412 | * negative error code. | |
413 | */ | |
414 | status = try_to_fill_dentry(dentry, flags); | |
415 | if (status == 0) | |
f50b6f86 IK |
416 | return 1; |
417 | ||
418 | /* | |
419 | * A status of EAGAIN here means that the dentry has gone | |
420 | * away while waiting for an expire to complete. If we are | |
421 | * racing with expire lookup will wait for it so this must | |
422 | * be a revalidate and we need to send it to lookup. | |
423 | */ | |
424 | if (status == -EAGAIN) | |
425 | return 0; | |
bcdc5e01 IK |
426 | |
427 | return status; | |
1da177e4 LT |
428 | } |
429 | ||
430 | /* Negative dentry.. invalidate if "old" */ | |
431 | if (dentry->d_inode == NULL) | |
2d753e62 | 432 | return 0; |
1da177e4 LT |
433 | |
434 | /* Check for a non-mountpoint directory with no contents */ | |
435 | spin_lock(&dcache_lock); | |
436 | if (S_ISDIR(dentry->d_inode->i_mode) && | |
437 | !d_mountpoint(dentry) && | |
90a59c7c | 438 | __simple_empty(dentry)) { |
1da177e4 LT |
439 | DPRINTK("dentry=%p %.*s, emptydir", |
440 | dentry, dentry->d_name.len, dentry->d_name.name); | |
441 | spin_unlock(&dcache_lock); | |
bcdc5e01 IK |
442 | /* The daemon never causes a mount to trigger */ |
443 | if (oz_mode) | |
444 | return 1; | |
445 | ||
446 | /* | |
447 | * A zero status is success otherwise we have a | |
448 | * negative error code. | |
449 | */ | |
450 | status = try_to_fill_dentry(dentry, flags); | |
451 | if (status == 0) | |
452 | return 1; | |
453 | ||
454 | return status; | |
1da177e4 LT |
455 | } |
456 | spin_unlock(&dcache_lock); | |
457 | ||
1da177e4 LT |
458 | return 1; |
459 | } | |
460 | ||
34ca959c | 461 | void autofs4_dentry_release(struct dentry *de) |
1da177e4 LT |
462 | { |
463 | struct autofs_info *inf; | |
464 | ||
465 | DPRINTK("releasing %p", de); | |
466 | ||
467 | inf = autofs4_dentry_ino(de); | |
468 | de->d_fsdata = NULL; | |
469 | ||
470 | if (inf) { | |
f50b6f86 IK |
471 | struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb); |
472 | ||
f50b6f86 IK |
473 | if (sbi) { |
474 | spin_lock(&sbi->rehash_lock); | |
475 | if (!list_empty(&inf->rehash)) | |
476 | list_del(&inf->rehash); | |
477 | spin_unlock(&sbi->rehash_lock); | |
478 | } | |
479 | ||
c3724b12 JM |
480 | inf->dentry = NULL; |
481 | inf->inode = NULL; | |
482 | ||
1da177e4 LT |
483 | autofs4_free_ino(inf); |
484 | } | |
485 | } | |
486 | ||
487 | /* For dentries of directories in the root dir */ | |
488 | static struct dentry_operations autofs4_root_dentry_operations = { | |
489 | .d_revalidate = autofs4_revalidate, | |
490 | .d_release = autofs4_dentry_release, | |
491 | }; | |
492 | ||
493 | /* For other dentries */ | |
494 | static struct dentry_operations autofs4_dentry_operations = { | |
495 | .d_revalidate = autofs4_revalidate, | |
496 | .d_release = autofs4_dentry_release, | |
497 | }; | |
498 | ||
f50b6f86 IK |
499 | static struct dentry *autofs4_lookup_unhashed(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name) |
500 | { | |
501 | unsigned int len = name->len; | |
502 | unsigned int hash = name->hash; | |
503 | const unsigned char *str = name->name; | |
504 | struct list_head *p, *head; | |
505 | ||
506 | spin_lock(&dcache_lock); | |
507 | spin_lock(&sbi->rehash_lock); | |
508 | head = &sbi->rehash_list; | |
509 | list_for_each(p, head) { | |
510 | struct autofs_info *ino; | |
511 | struct dentry *dentry; | |
512 | struct qstr *qstr; | |
513 | ||
514 | ino = list_entry(p, struct autofs_info, rehash); | |
515 | dentry = ino->dentry; | |
516 | ||
517 | spin_lock(&dentry->d_lock); | |
518 | ||
519 | /* Bad luck, we've already been dentry_iput */ | |
520 | if (!dentry->d_inode) | |
521 | goto next; | |
522 | ||
523 | qstr = &dentry->d_name; | |
524 | ||
525 | if (dentry->d_name.hash != hash) | |
526 | goto next; | |
527 | if (dentry->d_parent != parent) | |
528 | goto next; | |
529 | ||
530 | if (qstr->len != len) | |
531 | goto next; | |
532 | if (memcmp(qstr->name, str, len)) | |
533 | goto next; | |
534 | ||
535 | if (d_unhashed(dentry)) { | |
f50b6f86 IK |
536 | struct inode *inode = dentry->d_inode; |
537 | ||
f249fdd8 | 538 | ino = autofs4_dentry_ino(dentry); |
f50b6f86 IK |
539 | list_del_init(&ino->rehash); |
540 | dget(dentry); | |
541 | /* | |
542 | * Make the rehashed dentry negative so the VFS | |
543 | * behaves as it should. | |
544 | */ | |
545 | if (inode) { | |
546 | dentry->d_inode = NULL; | |
547 | list_del_init(&dentry->d_alias); | |
548 | spin_unlock(&dentry->d_lock); | |
549 | spin_unlock(&sbi->rehash_lock); | |
550 | spin_unlock(&dcache_lock); | |
551 | iput(inode); | |
552 | return dentry; | |
553 | } | |
554 | spin_unlock(&dentry->d_lock); | |
555 | spin_unlock(&sbi->rehash_lock); | |
556 | spin_unlock(&dcache_lock); | |
557 | return dentry; | |
558 | } | |
559 | next: | |
560 | spin_unlock(&dentry->d_lock); | |
561 | } | |
562 | spin_unlock(&sbi->rehash_lock); | |
563 | spin_unlock(&dcache_lock); | |
564 | ||
565 | return NULL; | |
566 | } | |
567 | ||
1da177e4 LT |
568 | /* Lookups in the root directory */ |
569 | static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
570 | { | |
571 | struct autofs_sb_info *sbi; | |
f50b6f86 | 572 | struct dentry *unhashed; |
1da177e4 LT |
573 | int oz_mode; |
574 | ||
575 | DPRINTK("name = %.*s", | |
576 | dentry->d_name.len, dentry->d_name.name); | |
577 | ||
718c604a | 578 | /* File name too long to exist */ |
1da177e4 | 579 | if (dentry->d_name.len > NAME_MAX) |
718c604a | 580 | return ERR_PTR(-ENAMETOOLONG); |
1da177e4 LT |
581 | |
582 | sbi = autofs4_sbi(dir->i_sb); | |
1da177e4 | 583 | oz_mode = autofs4_oz_mode(sbi); |
718c604a | 584 | |
1da177e4 | 585 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
a47afb0f | 586 | current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); |
1da177e4 | 587 | |
f50b6f86 IK |
588 | unhashed = autofs4_lookup_unhashed(sbi, dentry->d_parent, &dentry->d_name); |
589 | if (!unhashed) { | |
590 | /* | |
1864f7bd IK |
591 | * Mark the dentry incomplete but don't hash it. We do this |
592 | * to serialize our inode creation operations (symlink and | |
593 | * mkdir) which prevents deadlock during the callback to | |
594 | * the daemon. Subsequent user space lookups for the same | |
595 | * dentry are placed on the wait queue while the daemon | |
596 | * itself is allowed passage unresticted so the create | |
597 | * operation itself can then hash the dentry. Finally, | |
598 | * we check for the hashed dentry and return the newly | |
599 | * hashed dentry. | |
f50b6f86 IK |
600 | */ |
601 | dentry->d_op = &autofs4_root_dentry_operations; | |
602 | ||
603 | dentry->d_fsdata = NULL; | |
1864f7bd | 604 | d_instantiate(dentry, NULL); |
f50b6f86 IK |
605 | } else { |
606 | struct autofs_info *ino = autofs4_dentry_ino(unhashed); | |
607 | DPRINTK("rehash %p with %p", dentry, unhashed); | |
608 | /* | |
609 | * If we are racing with expire the request might not | |
610 | * be quite complete but the directory has been removed | |
611 | * so it must have been successful, so just wait for it. | |
1864f7bd IK |
612 | * We need to ensure the AUTOFS_INF_EXPIRING flag is clear |
613 | * before continuing as revalidate may fail when calling | |
614 | * try_to_fill_dentry (returning EAGAIN) if we don't. | |
f50b6f86 | 615 | */ |
1864f7bd | 616 | while (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { |
f50b6f86 IK |
617 | DPRINTK("wait for incomplete expire %p name=%.*s", |
618 | unhashed, unhashed->d_name.len, | |
619 | unhashed->d_name.name); | |
620 | autofs4_wait(sbi, unhashed, NFY_NONE); | |
621 | DPRINTK("request completed"); | |
622 | } | |
f50b6f86 IK |
623 | dentry = unhashed; |
624 | } | |
1da177e4 LT |
625 | |
626 | if (!oz_mode) { | |
627 | spin_lock(&dentry->d_lock); | |
628 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
629 | spin_unlock(&dentry->d_lock); | |
630 | } | |
1da177e4 LT |
631 | |
632 | if (dentry->d_op && dentry->d_op->d_revalidate) { | |
1b1dcc1b | 633 | mutex_unlock(&dir->i_mutex); |
1da177e4 | 634 | (dentry->d_op->d_revalidate)(dentry, nd); |
1b1dcc1b | 635 | mutex_lock(&dir->i_mutex); |
1da177e4 LT |
636 | } |
637 | ||
638 | /* | |
639 | * If we are still pending, check if we had to handle | |
640 | * a signal. If so we can force a restart.. | |
641 | */ | |
642 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { | |
643 | /* See if we were interrupted */ | |
644 | if (signal_pending(current)) { | |
645 | sigset_t *sigset = ¤t->pending.signal; | |
646 | if (sigismember (sigset, SIGKILL) || | |
647 | sigismember (sigset, SIGQUIT) || | |
648 | sigismember (sigset, SIGINT)) { | |
f50b6f86 IK |
649 | if (unhashed) |
650 | dput(unhashed); | |
1da177e4 LT |
651 | return ERR_PTR(-ERESTARTNOINTR); |
652 | } | |
653 | } | |
44938af6 IK |
654 | spin_lock(&dentry->d_lock); |
655 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
656 | spin_unlock(&dentry->d_lock); | |
1da177e4 LT |
657 | } |
658 | ||
659 | /* | |
660 | * If this dentry is unhashed, then we shouldn't honour this | |
c9ffec48 IK |
661 | * lookup. Returning ENOENT here doesn't do the right thing |
662 | * for all system calls, but it should be OK for the operations | |
663 | * we permit from an autofs. | |
1da177e4 | 664 | */ |
1864f7bd | 665 | if (!oz_mode && d_unhashed(dentry)) { |
c9ffec48 IK |
666 | /* |
667 | * A user space application can (and has done in the past) | |
668 | * remove and re-create this directory during the callback. | |
669 | * This can leave us with an unhashed dentry, but a | |
670 | * successful mount! So we need to perform another | |
671 | * cached lookup in case the dentry now exists. | |
672 | */ | |
673 | struct dentry *parent = dentry->d_parent; | |
674 | struct dentry *new = d_lookup(parent, &dentry->d_name); | |
675 | if (new != NULL) | |
676 | dentry = new; | |
677 | else | |
678 | dentry = ERR_PTR(-ENOENT); | |
679 | ||
f50b6f86 IK |
680 | if (unhashed) |
681 | dput(unhashed); | |
c9ffec48 IK |
682 | |
683 | return dentry; | |
f50b6f86 IK |
684 | } |
685 | ||
686 | if (unhashed) | |
687 | return dentry; | |
1da177e4 LT |
688 | |
689 | return NULL; | |
690 | } | |
691 | ||
692 | static int autofs4_dir_symlink(struct inode *dir, | |
693 | struct dentry *dentry, | |
694 | const char *symname) | |
695 | { | |
696 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
697 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 698 | struct autofs_info *p_ino; |
1da177e4 LT |
699 | struct inode *inode; |
700 | char *cp; | |
701 | ||
702 | DPRINTK("%s <- %.*s", symname, | |
703 | dentry->d_name.len, dentry->d_name.name); | |
704 | ||
705 | if (!autofs4_oz_mode(sbi)) | |
706 | return -EACCES; | |
707 | ||
708 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
709 | if (ino == NULL) | |
710 | return -ENOSPC; | |
711 | ||
712 | ino->size = strlen(symname); | |
713 | ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL); | |
714 | ||
715 | if (cp == NULL) { | |
716 | kfree(ino); | |
717 | return -ENOSPC; | |
718 | } | |
719 | ||
720 | strcpy(cp, symname); | |
721 | ||
722 | inode = autofs4_get_inode(dir->i_sb, ino); | |
1864f7bd | 723 | d_add(dentry, inode); |
1da177e4 LT |
724 | |
725 | if (dir == dir->i_sb->s_root->d_inode) | |
726 | dentry->d_op = &autofs4_root_dentry_operations; | |
727 | else | |
728 | dentry->d_op = &autofs4_dentry_operations; | |
729 | ||
730 | dentry->d_fsdata = ino; | |
731 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
732 | atomic_inc(&ino->count); |
733 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
734 | if (p_ino && dentry->d_parent != dentry) | |
735 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
736 | ino->inode = inode; |
737 | ||
738 | dir->i_mtime = CURRENT_TIME; | |
739 | ||
740 | return 0; | |
741 | } | |
742 | ||
743 | /* | |
744 | * NOTE! | |
745 | * | |
746 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
747 | * that the file no longer exists. However, doing that means that the | |
748 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 IK |
749 | * this, because the unlink is probably the result of an expire. |
750 | * We simply d_drop it and add it to a rehash candidates list in the | |
751 | * super block, which allows the dentry lookup to reuse it retaining | |
752 | * the flags, such as expire in progress, in case we're racing with expire. | |
1da177e4 LT |
753 | * |
754 | * If a process is blocked on the dentry waiting for the expire to finish, | |
755 | * it will invalidate the dentry and try to mount with a new one. | |
756 | * | |
757 | * Also see autofs4_dir_rmdir().. | |
758 | */ | |
759 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
760 | { | |
761 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
762 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 763 | struct autofs_info *p_ino; |
1da177e4 LT |
764 | |
765 | /* This allows root to remove symlinks */ | |
d78e53c8 | 766 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
767 | return -EACCES; |
768 | ||
1aff3c8b IK |
769 | if (atomic_dec_and_test(&ino->count)) { |
770 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
771 | if (p_ino && dentry->d_parent != dentry) | |
772 | atomic_dec(&p_ino->count); | |
773 | } | |
1da177e4 LT |
774 | dput(ino->dentry); |
775 | ||
776 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 777 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
778 | |
779 | dir->i_mtime = CURRENT_TIME; | |
780 | ||
f50b6f86 IK |
781 | spin_lock(&dcache_lock); |
782 | spin_lock(&sbi->rehash_lock); | |
783 | list_add(&ino->rehash, &sbi->rehash_list); | |
784 | spin_unlock(&sbi->rehash_lock); | |
785 | spin_lock(&dentry->d_lock); | |
786 | __d_drop(dentry); | |
787 | spin_unlock(&dentry->d_lock); | |
788 | spin_unlock(&dcache_lock); | |
1da177e4 LT |
789 | |
790 | return 0; | |
791 | } | |
792 | ||
793 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
794 | { | |
795 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
796 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 797 | struct autofs_info *p_ino; |
1da177e4 | 798 | |
f50b6f86 IK |
799 | DPRINTK("dentry %p, removing %.*s", |
800 | dentry, dentry->d_name.len, dentry->d_name.name); | |
801 | ||
1da177e4 LT |
802 | if (!autofs4_oz_mode(sbi)) |
803 | return -EACCES; | |
804 | ||
805 | spin_lock(&dcache_lock); | |
806 | if (!list_empty(&dentry->d_subdirs)) { | |
807 | spin_unlock(&dcache_lock); | |
808 | return -ENOTEMPTY; | |
809 | } | |
f50b6f86 IK |
810 | spin_lock(&sbi->rehash_lock); |
811 | list_add(&ino->rehash, &sbi->rehash_list); | |
812 | spin_unlock(&sbi->rehash_lock); | |
1da177e4 LT |
813 | spin_lock(&dentry->d_lock); |
814 | __d_drop(dentry); | |
815 | spin_unlock(&dentry->d_lock); | |
816 | spin_unlock(&dcache_lock); | |
817 | ||
1aff3c8b IK |
818 | if (atomic_dec_and_test(&ino->count)) { |
819 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
820 | if (p_ino && dentry->d_parent != dentry) | |
821 | atomic_dec(&p_ino->count); | |
822 | } | |
1da177e4 | 823 | dput(ino->dentry); |
1da177e4 | 824 | dentry->d_inode->i_size = 0; |
ce71ec36 | 825 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
826 | |
827 | if (dir->i_nlink) | |
9a53c3a7 | 828 | drop_nlink(dir); |
1da177e4 LT |
829 | |
830 | return 0; | |
831 | } | |
832 | ||
833 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
834 | { | |
835 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
836 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 837 | struct autofs_info *p_ino; |
1da177e4 LT |
838 | struct inode *inode; |
839 | ||
d78e53c8 | 840 | if (!autofs4_oz_mode(sbi)) |
1da177e4 LT |
841 | return -EACCES; |
842 | ||
843 | DPRINTK("dentry %p, creating %.*s", | |
844 | dentry, dentry->d_name.len, dentry->d_name.name); | |
845 | ||
846 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
847 | if (ino == NULL) | |
848 | return -ENOSPC; | |
849 | ||
850 | inode = autofs4_get_inode(dir->i_sb, ino); | |
1864f7bd | 851 | d_add(dentry, inode); |
1da177e4 LT |
852 | |
853 | if (dir == dir->i_sb->s_root->d_inode) | |
854 | dentry->d_op = &autofs4_root_dentry_operations; | |
855 | else | |
856 | dentry->d_op = &autofs4_dentry_operations; | |
857 | ||
858 | dentry->d_fsdata = ino; | |
859 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
860 | atomic_inc(&ino->count); |
861 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
862 | if (p_ino && dentry->d_parent != dentry) | |
863 | atomic_inc(&p_ino->count); | |
1da177e4 | 864 | ino->inode = inode; |
d8c76e6f | 865 | inc_nlink(dir); |
1da177e4 LT |
866 | dir->i_mtime = CURRENT_TIME; |
867 | ||
868 | return 0; | |
869 | } | |
870 | ||
871 | /* Get/set timeout ioctl() operation */ | |
872 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, | |
873 | unsigned long __user *p) | |
874 | { | |
875 | int rv; | |
876 | unsigned long ntimeout; | |
877 | ||
d78e53c8 SB |
878 | if ((rv = get_user(ntimeout, p)) || |
879 | (rv = put_user(sbi->exp_timeout/HZ, p))) | |
1da177e4 LT |
880 | return rv; |
881 | ||
d78e53c8 | 882 | if (ntimeout > ULONG_MAX/HZ) |
1da177e4 LT |
883 | sbi->exp_timeout = 0; |
884 | else | |
885 | sbi->exp_timeout = ntimeout * HZ; | |
886 | ||
887 | return 0; | |
888 | } | |
889 | ||
890 | /* Return protocol version */ | |
891 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
892 | { | |
893 | return put_user(sbi->version, p); | |
894 | } | |
895 | ||
896 | /* Return protocol sub version */ | |
897 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
898 | { | |
899 | return put_user(sbi->sub_version, p); | |
900 | } | |
901 | ||
902 | /* | |
903 | * Tells the daemon whether we need to reghost or not. Also, clears | |
904 | * the reghost_needed flag. | |
905 | */ | |
906 | static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p) | |
907 | { | |
908 | int status; | |
909 | ||
910 | DPRINTK("returning %d", sbi->needs_reghost); | |
911 | ||
912 | status = put_user(sbi->needs_reghost, p); | |
d78e53c8 | 913 | if (status) |
1da177e4 LT |
914 | return status; |
915 | ||
916 | sbi->needs_reghost = 0; | |
917 | return 0; | |
918 | } | |
919 | ||
920 | /* | |
921 | * Enable / Disable reghosting ioctl() operation | |
922 | */ | |
923 | static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p) | |
924 | { | |
925 | int status; | |
926 | int val; | |
927 | ||
928 | status = get_user(val, p); | |
929 | ||
930 | DPRINTK("reghost = %d", val); | |
931 | ||
932 | if (status) | |
933 | return status; | |
934 | ||
935 | /* turn on/off reghosting, with the val */ | |
936 | sbi->reghost_enabled = val; | |
937 | return 0; | |
938 | } | |
939 | ||
940 | /* | |
941 | * Tells the daemon whether it can umount the autofs mount. | |
942 | */ | |
943 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
944 | { | |
945 | int status = 0; | |
946 | ||
e3474a8e | 947 | if (may_umount(mnt)) |
1da177e4 LT |
948 | status = 1; |
949 | ||
950 | DPRINTK("returning %d", status); | |
951 | ||
952 | status = put_user(status, p); | |
953 | ||
954 | return status; | |
955 | } | |
956 | ||
957 | /* Identify autofs4_dentries - this is so we can tell if there's | |
958 | an extra dentry refcount or not. We only hold a refcount on the | |
959 | dentry if its non-negative (ie, d_inode != NULL) | |
960 | */ | |
961 | int is_autofs4_dentry(struct dentry *dentry) | |
962 | { | |
963 | return dentry && dentry->d_inode && | |
964 | (dentry->d_op == &autofs4_root_dentry_operations || | |
965 | dentry->d_op == &autofs4_dentry_operations) && | |
966 | dentry->d_fsdata != NULL; | |
967 | } | |
968 | ||
969 | /* | |
970 | * ioctl()'s on the root directory is the chief method for the daemon to | |
971 | * generate kernel reactions | |
972 | */ | |
973 | static int autofs4_root_ioctl(struct inode *inode, struct file *filp, | |
974 | unsigned int cmd, unsigned long arg) | |
975 | { | |
976 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
977 | void __user *p = (void __user *)arg; | |
978 | ||
979 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
a47afb0f | 980 | cmd,arg,sbi,task_pgrp_nr(current)); |
1da177e4 | 981 | |
d78e53c8 SB |
982 | if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || |
983 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT) | |
1da177e4 LT |
984 | return -ENOTTY; |
985 | ||
d78e53c8 | 986 | if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) |
1da177e4 LT |
987 | return -EPERM; |
988 | ||
989 | switch(cmd) { | |
990 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
991 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
992 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
993 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
994 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
995 | autofs4_catatonic_mode(sbi); | |
996 | return 0; | |
997 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
998 | return autofs4_get_protover(sbi, p); | |
999 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
1000 | return autofs4_get_protosubver(sbi, p); | |
1001 | case AUTOFS_IOC_SETTIMEOUT: | |
1002 | return autofs4_get_set_timeout(sbi, p); | |
1003 | ||
1004 | case AUTOFS_IOC_TOGGLEREGHOST: | |
1005 | return autofs4_toggle_reghost(sbi, p); | |
1006 | case AUTOFS_IOC_ASKREGHOST: | |
1007 | return autofs4_ask_reghost(sbi, p); | |
1008 | ||
1009 | case AUTOFS_IOC_ASKUMOUNT: | |
a4669ed8 | 1010 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
1011 | |
1012 | /* return a single thing to expire */ | |
1013 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 1014 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
1015 | /* same as above, but can send multiple expires through pipe */ |
1016 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 1017 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
1018 | |
1019 | default: | |
1020 | return -ENOSYS; | |
1021 | } | |
1022 | } |