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Commit | Line | Data |
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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 | ||
754661f1 | 50 | const 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 | ||
754661f1 | 58 | const struct inode_operations autofs4_direct_root_inode_operations = { |
34ca959c | 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 | ||
754661f1 | 66 | const struct inode_operations autofs4_dir_inode_operations = { |
1da177e4 LT |
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 | { | |
a4669ed8 | 77 | struct autofs_sb_info *sbi = autofs4_sbi(file->f_path.dentry->d_sb); |
1da177e4 LT |
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 | { | |
a4669ed8 JJS |
98 | struct dentry *dentry = file->f_path.dentry; |
99 | struct vfsmount *mnt = file->f_path.mnt; | |
1da177e4 | 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 | |
bcdc5e01 IK |
140 | if (ret <= 0) { |
141 | if (ret < 0) | |
142 | status = ret; | |
f360ce3b IK |
143 | dcache_dir_close(inode, file); |
144 | goto out; | |
145 | } | |
1da177e4 LT |
146 | } |
147 | ||
148 | if (d_mountpoint(dentry)) { | |
149 | struct file *fp = NULL; | |
150 | struct vfsmount *fp_mnt = mntget(mnt); | |
151 | struct dentry *fp_dentry = dget(dentry); | |
152 | ||
9b1e3afd IK |
153 | if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) { |
154 | dput(fp_dentry); | |
155 | mntput(fp_mnt); | |
f360ce3b IK |
156 | dcache_dir_close(inode, file); |
157 | goto out; | |
9b1e3afd | 158 | } |
1da177e4 LT |
159 | |
160 | fp = dentry_open(fp_dentry, fp_mnt, file->f_flags); | |
161 | status = PTR_ERR(fp); | |
162 | if (IS_ERR(fp)) { | |
f360ce3b IK |
163 | dcache_dir_close(inode, file); |
164 | goto out; | |
1da177e4 | 165 | } |
f360ce3b | 166 | cursor->d_fsdata = fp; |
1da177e4 | 167 | } |
1da177e4 | 168 | return 0; |
f360ce3b IK |
169 | out: |
170 | return status; | |
1da177e4 LT |
171 | } |
172 | ||
173 | static int autofs4_dir_close(struct inode *inode, struct file *file) | |
174 | { | |
a4669ed8 | 175 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 176 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b IK |
177 | struct dentry *cursor = file->private_data; |
178 | int status = 0; | |
1da177e4 LT |
179 | |
180 | DPRINTK("file=%p dentry=%p %.*s", | |
181 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
182 | ||
183 | if (autofs4_oz_mode(sbi)) | |
184 | goto out; | |
185 | ||
186 | if (autofs4_ispending(dentry)) { | |
187 | DPRINTK("dentry busy"); | |
f360ce3b IK |
188 | status = -EBUSY; |
189 | goto out; | |
1da177e4 LT |
190 | } |
191 | ||
192 | if (d_mountpoint(dentry)) { | |
f360ce3b IK |
193 | struct file *fp = cursor->d_fsdata; |
194 | if (!fp) { | |
195 | status = -ENOENT; | |
196 | goto out; | |
197 | } | |
1da177e4 | 198 | filp_close(fp, current->files); |
1da177e4 LT |
199 | } |
200 | out: | |
f360ce3b IK |
201 | dcache_dir_close(inode, file); |
202 | return status; | |
1da177e4 LT |
203 | } |
204 | ||
205 | static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir) | |
206 | { | |
a4669ed8 | 207 | struct dentry *dentry = file->f_path.dentry; |
1da177e4 | 208 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
f360ce3b | 209 | struct dentry *cursor = file->private_data; |
1da177e4 LT |
210 | int status; |
211 | ||
212 | DPRINTK("file=%p dentry=%p %.*s", | |
213 | file, dentry, dentry->d_name.len, dentry->d_name.name); | |
214 | ||
215 | if (autofs4_oz_mode(sbi)) | |
216 | goto out; | |
217 | ||
218 | if (autofs4_ispending(dentry)) { | |
219 | DPRINTK("dentry busy"); | |
220 | return -EBUSY; | |
221 | } | |
222 | ||
223 | if (d_mountpoint(dentry)) { | |
f360ce3b | 224 | struct file *fp = cursor->d_fsdata; |
1da177e4 LT |
225 | |
226 | if (!fp) | |
227 | return -ENOENT; | |
228 | ||
229 | if (!fp->f_op || !fp->f_op->readdir) | |
230 | goto out; | |
231 | ||
232 | status = vfs_readdir(fp, filldir, dirent); | |
233 | file->f_pos = fp->f_pos; | |
234 | if (status) | |
235 | autofs4_copy_atime(file, fp); | |
236 | return status; | |
237 | } | |
238 | out: | |
f360ce3b | 239 | return dcache_readdir(file, dirent, filldir); |
1da177e4 LT |
240 | } |
241 | ||
862b110f | 242 | static int try_to_fill_dentry(struct dentry *dentry, int flags) |
1da177e4 | 243 | { |
862b110f | 244 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); |
718c604a | 245 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
1da177e4 LT |
246 | int status = 0; |
247 | ||
248 | /* Block on any pending expiry here; invalidate the dentry | |
249 | when expiration is done to trigger mount request with a new | |
250 | dentry */ | |
718c604a | 251 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { |
1da177e4 LT |
252 | DPRINTK("waiting for expire %p name=%.*s", |
253 | dentry, dentry->d_name.len, dentry->d_name.name); | |
254 | ||
255 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
718c604a | 256 | |
1da177e4 | 257 | DPRINTK("expire done status=%d", status); |
718c604a | 258 | |
1684b2bb IK |
259 | /* |
260 | * If the directory still exists the mount request must | |
261 | * continue otherwise it can't be followed at the right | |
262 | * time during the walk. | |
263 | */ | |
264 | status = d_invalidate(dentry); | |
265 | if (status != -EBUSY) | |
f50b6f86 | 266 | return -EAGAIN; |
1da177e4 LT |
267 | } |
268 | ||
269 | DPRINTK("dentry=%p %.*s ino=%p", | |
270 | dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); | |
271 | ||
718c604a IK |
272 | /* |
273 | * Wait for a pending mount, triggering one if there | |
274 | * isn't one already | |
275 | */ | |
1da177e4 LT |
276 | if (dentry->d_inode == NULL) { |
277 | DPRINTK("waiting for mount name=%.*s", | |
278 | dentry->d_name.len, dentry->d_name.name); | |
279 | ||
280 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
718c604a | 281 | |
1da177e4 LT |
282 | DPRINTK("mount done status=%d", status); |
283 | ||
1da177e4 LT |
284 | /* Turn this into a real negative dentry? */ |
285 | if (status == -ENOENT) { | |
1da177e4 LT |
286 | spin_lock(&dentry->d_lock); |
287 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
288 | spin_unlock(&dentry->d_lock); | |
34ca959c | 289 | return status; |
1da177e4 LT |
290 | } else if (status) { |
291 | /* Return a negative dentry, but leave it "pending" */ | |
34ca959c | 292 | return status; |
1da177e4 LT |
293 | } |
294 | /* Trigger mount for path component or follow link */ | |
295 | } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) || | |
296 | current->link_count) { | |
297 | DPRINTK("waiting for mount name=%.*s", | |
298 | dentry->d_name.len, dentry->d_name.name); | |
299 | ||
300 | spin_lock(&dentry->d_lock); | |
301 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
302 | spin_unlock(&dentry->d_lock); | |
303 | status = autofs4_wait(sbi, dentry, NFY_MOUNT); | |
304 | ||
305 | DPRINTK("mount done status=%d", status); | |
306 | ||
307 | if (status) { | |
308 | spin_lock(&dentry->d_lock); | |
309 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
310 | spin_unlock(&dentry->d_lock); | |
34ca959c | 311 | return status; |
1da177e4 LT |
312 | } |
313 | } | |
314 | ||
e0a7aae9 IK |
315 | /* Initialize expiry counter after successful mount */ |
316 | if (ino) | |
317 | ino->last_used = jiffies; | |
318 | ||
1da177e4 LT |
319 | spin_lock(&dentry->d_lock); |
320 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
321 | spin_unlock(&dentry->d_lock); | |
34ca959c IK |
322 | return status; |
323 | } | |
324 | ||
325 | /* For autofs direct mounts the follow link triggers the mount */ | |
326 | static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) | |
327 | { | |
328 | struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); | |
a5370553 | 329 | struct autofs_info *ino = autofs4_dentry_ino(dentry); |
34ca959c IK |
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 | ||
a5370553 IK |
343 | /* If an expire request is pending wait for it. */ |
344 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { | |
871f9434 IK |
345 | DPRINTK("waiting for active request %p name=%.*s", |
346 | dentry, dentry->d_name.len, dentry->d_name.name); | |
347 | ||
348 | status = autofs4_wait(sbi, dentry, NFY_NONE); | |
349 | ||
350 | DPRINTK("request done status=%d", status); | |
351 | } | |
34ca959c | 352 | |
871f9434 IK |
353 | /* |
354 | * If the dentry contains directories then it is an | |
355 | * autofs multi-mount with no root mount offset. So | |
356 | * don't try to mount it again. | |
357 | */ | |
358 | spin_lock(&dcache_lock); | |
be3ca7fe | 359 | if (!d_mountpoint(dentry) && __simple_empty(dentry)) { |
871f9434 IK |
360 | spin_unlock(&dcache_lock); |
361 | ||
362 | status = try_to_fill_dentry(dentry, 0); | |
363 | if (status) | |
364 | goto out_error; | |
365 | ||
366 | /* | |
367 | * The mount succeeded but if there is no root mount | |
368 | * it must be an autofs multi-mount with no root offset | |
369 | * so we don't need to follow the mount. | |
370 | */ | |
371 | if (d_mountpoint(dentry)) { | |
372 | if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) { | |
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: | |
386 | path_release(nd); | |
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 | ||
1da177e4 LT |
473 | inf->dentry = NULL; |
474 | inf->inode = NULL; | |
475 | ||
f50b6f86 IK |
476 | if (sbi) { |
477 | spin_lock(&sbi->rehash_lock); | |
478 | if (!list_empty(&inf->rehash)) | |
479 | list_del(&inf->rehash); | |
480 | spin_unlock(&sbi->rehash_lock); | |
481 | } | |
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)) { | |
536 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
537 | struct inode *inode = dentry->d_inode; | |
538 | ||
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 LT |
585 | DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", |
586 | current->pid, process_group(current), sbi->catatonic, oz_mode); | |
587 | ||
f50b6f86 IK |
588 | unhashed = autofs4_lookup_unhashed(sbi, dentry->d_parent, &dentry->d_name); |
589 | if (!unhashed) { | |
590 | /* | |
591 | * Mark the dentry incomplete, but add it. This is needed so | |
592 | * that the VFS layer knows about the dentry, and we can count | |
593 | * on catching any lookups through the revalidate. | |
594 | * | |
595 | * Let all the hard work be done by the revalidate function that | |
596 | * needs to be able to do this anyway.. | |
597 | * | |
598 | * We need to do this before we release the directory semaphore. | |
599 | */ | |
600 | dentry->d_op = &autofs4_root_dentry_operations; | |
601 | ||
602 | dentry->d_fsdata = NULL; | |
603 | d_add(dentry, NULL); | |
604 | } else { | |
605 | struct autofs_info *ino = autofs4_dentry_ino(unhashed); | |
606 | DPRINTK("rehash %p with %p", dentry, unhashed); | |
607 | /* | |
608 | * If we are racing with expire the request might not | |
609 | * be quite complete but the directory has been removed | |
610 | * so it must have been successful, so just wait for it. | |
611 | */ | |
612 | if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { | |
613 | DPRINTK("wait for incomplete expire %p name=%.*s", | |
614 | unhashed, unhashed->d_name.len, | |
615 | unhashed->d_name.name); | |
616 | autofs4_wait(sbi, unhashed, NFY_NONE); | |
617 | DPRINTK("request completed"); | |
618 | } | |
619 | d_rehash(unhashed); | |
620 | dentry = unhashed; | |
621 | } | |
1da177e4 LT |
622 | |
623 | if (!oz_mode) { | |
624 | spin_lock(&dentry->d_lock); | |
625 | dentry->d_flags |= DCACHE_AUTOFS_PENDING; | |
626 | spin_unlock(&dentry->d_lock); | |
627 | } | |
1da177e4 LT |
628 | |
629 | if (dentry->d_op && dentry->d_op->d_revalidate) { | |
1b1dcc1b | 630 | mutex_unlock(&dir->i_mutex); |
1da177e4 | 631 | (dentry->d_op->d_revalidate)(dentry, nd); |
1b1dcc1b | 632 | mutex_lock(&dir->i_mutex); |
1da177e4 LT |
633 | } |
634 | ||
635 | /* | |
636 | * If we are still pending, check if we had to handle | |
637 | * a signal. If so we can force a restart.. | |
638 | */ | |
639 | if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { | |
640 | /* See if we were interrupted */ | |
641 | if (signal_pending(current)) { | |
642 | sigset_t *sigset = ¤t->pending.signal; | |
643 | if (sigismember (sigset, SIGKILL) || | |
644 | sigismember (sigset, SIGQUIT) || | |
645 | sigismember (sigset, SIGINT)) { | |
f50b6f86 IK |
646 | if (unhashed) |
647 | dput(unhashed); | |
1da177e4 LT |
648 | return ERR_PTR(-ERESTARTNOINTR); |
649 | } | |
650 | } | |
44938af6 IK |
651 | spin_lock(&dentry->d_lock); |
652 | dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; | |
653 | spin_unlock(&dentry->d_lock); | |
1da177e4 LT |
654 | } |
655 | ||
656 | /* | |
657 | * If this dentry is unhashed, then we shouldn't honour this | |
658 | * lookup even if the dentry is positive. Returning ENOENT here | |
659 | * doesn't do the right thing for all system calls, but it should | |
660 | * be OK for the operations we permit from an autofs. | |
661 | */ | |
f50b6f86 IK |
662 | if (dentry->d_inode && d_unhashed(dentry)) { |
663 | if (unhashed) | |
664 | dput(unhashed); | |
1da177e4 | 665 | return ERR_PTR(-ENOENT); |
f50b6f86 IK |
666 | } |
667 | ||
668 | if (unhashed) | |
669 | return dentry; | |
1da177e4 LT |
670 | |
671 | return NULL; | |
672 | } | |
673 | ||
674 | static int autofs4_dir_symlink(struct inode *dir, | |
675 | struct dentry *dentry, | |
676 | const char *symname) | |
677 | { | |
678 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
679 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 680 | struct autofs_info *p_ino; |
1da177e4 LT |
681 | struct inode *inode; |
682 | char *cp; | |
683 | ||
684 | DPRINTK("%s <- %.*s", symname, | |
685 | dentry->d_name.len, dentry->d_name.name); | |
686 | ||
687 | if (!autofs4_oz_mode(sbi)) | |
688 | return -EACCES; | |
689 | ||
690 | ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); | |
691 | if (ino == NULL) | |
692 | return -ENOSPC; | |
693 | ||
694 | ino->size = strlen(symname); | |
695 | ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL); | |
696 | ||
697 | if (cp == NULL) { | |
698 | kfree(ino); | |
699 | return -ENOSPC; | |
700 | } | |
701 | ||
702 | strcpy(cp, symname); | |
703 | ||
704 | inode = autofs4_get_inode(dir->i_sb, ino); | |
705 | d_instantiate(dentry, inode); | |
706 | ||
707 | if (dir == dir->i_sb->s_root->d_inode) | |
708 | dentry->d_op = &autofs4_root_dentry_operations; | |
709 | else | |
710 | dentry->d_op = &autofs4_dentry_operations; | |
711 | ||
712 | dentry->d_fsdata = ino; | |
713 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
714 | atomic_inc(&ino->count); |
715 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
716 | if (p_ino && dentry->d_parent != dentry) | |
717 | atomic_inc(&p_ino->count); | |
1da177e4 LT |
718 | ino->inode = inode; |
719 | ||
720 | dir->i_mtime = CURRENT_TIME; | |
721 | ||
722 | return 0; | |
723 | } | |
724 | ||
725 | /* | |
726 | * NOTE! | |
727 | * | |
728 | * Normal filesystems would do a "d_delete()" to tell the VFS dcache | |
729 | * that the file no longer exists. However, doing that means that the | |
730 | * VFS layer can turn the dentry into a negative dentry. We don't want | |
f50b6f86 IK |
731 | * this, because the unlink is probably the result of an expire. |
732 | * We simply d_drop it and add it to a rehash candidates list in the | |
733 | * super block, which allows the dentry lookup to reuse it retaining | |
734 | * the flags, such as expire in progress, in case we're racing with expire. | |
1da177e4 LT |
735 | * |
736 | * If a process is blocked on the dentry waiting for the expire to finish, | |
737 | * it will invalidate the dentry and try to mount with a new one. | |
738 | * | |
739 | * Also see autofs4_dir_rmdir().. | |
740 | */ | |
741 | static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) | |
742 | { | |
743 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
744 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 745 | struct autofs_info *p_ino; |
1da177e4 LT |
746 | |
747 | /* This allows root to remove symlinks */ | |
748 | if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) | |
749 | return -EACCES; | |
750 | ||
1aff3c8b IK |
751 | if (atomic_dec_and_test(&ino->count)) { |
752 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
753 | if (p_ino && dentry->d_parent != dentry) | |
754 | atomic_dec(&p_ino->count); | |
755 | } | |
1da177e4 LT |
756 | dput(ino->dentry); |
757 | ||
758 | dentry->d_inode->i_size = 0; | |
ce71ec36 | 759 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
760 | |
761 | dir->i_mtime = CURRENT_TIME; | |
762 | ||
f50b6f86 IK |
763 | spin_lock(&dcache_lock); |
764 | spin_lock(&sbi->rehash_lock); | |
765 | list_add(&ino->rehash, &sbi->rehash_list); | |
766 | spin_unlock(&sbi->rehash_lock); | |
767 | spin_lock(&dentry->d_lock); | |
768 | __d_drop(dentry); | |
769 | spin_unlock(&dentry->d_lock); | |
770 | spin_unlock(&dcache_lock); | |
1da177e4 LT |
771 | |
772 | return 0; | |
773 | } | |
774 | ||
775 | static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) | |
776 | { | |
777 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
778 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 779 | struct autofs_info *p_ino; |
1da177e4 | 780 | |
f50b6f86 IK |
781 | DPRINTK("dentry %p, removing %.*s", |
782 | dentry, dentry->d_name.len, dentry->d_name.name); | |
783 | ||
1da177e4 LT |
784 | if (!autofs4_oz_mode(sbi)) |
785 | return -EACCES; | |
786 | ||
787 | spin_lock(&dcache_lock); | |
788 | if (!list_empty(&dentry->d_subdirs)) { | |
789 | spin_unlock(&dcache_lock); | |
790 | return -ENOTEMPTY; | |
791 | } | |
f50b6f86 IK |
792 | spin_lock(&sbi->rehash_lock); |
793 | list_add(&ino->rehash, &sbi->rehash_list); | |
794 | spin_unlock(&sbi->rehash_lock); | |
1da177e4 LT |
795 | spin_lock(&dentry->d_lock); |
796 | __d_drop(dentry); | |
797 | spin_unlock(&dentry->d_lock); | |
798 | spin_unlock(&dcache_lock); | |
799 | ||
1aff3c8b IK |
800 | if (atomic_dec_and_test(&ino->count)) { |
801 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
802 | if (p_ino && dentry->d_parent != dentry) | |
803 | atomic_dec(&p_ino->count); | |
804 | } | |
1da177e4 | 805 | dput(ino->dentry); |
1da177e4 | 806 | dentry->d_inode->i_size = 0; |
ce71ec36 | 807 | clear_nlink(dentry->d_inode); |
1da177e4 LT |
808 | |
809 | if (dir->i_nlink) | |
9a53c3a7 | 810 | drop_nlink(dir); |
1da177e4 LT |
811 | |
812 | return 0; | |
813 | } | |
814 | ||
815 | static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
816 | { | |
817 | struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); | |
818 | struct autofs_info *ino = autofs4_dentry_ino(dentry); | |
1aff3c8b | 819 | struct autofs_info *p_ino; |
1da177e4 LT |
820 | struct inode *inode; |
821 | ||
822 | if ( !autofs4_oz_mode(sbi) ) | |
823 | return -EACCES; | |
824 | ||
825 | DPRINTK("dentry %p, creating %.*s", | |
826 | dentry, dentry->d_name.len, dentry->d_name.name); | |
827 | ||
828 | ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); | |
829 | if (ino == NULL) | |
830 | return -ENOSPC; | |
831 | ||
832 | inode = autofs4_get_inode(dir->i_sb, ino); | |
833 | d_instantiate(dentry, inode); | |
834 | ||
835 | if (dir == dir->i_sb->s_root->d_inode) | |
836 | dentry->d_op = &autofs4_root_dentry_operations; | |
837 | else | |
838 | dentry->d_op = &autofs4_dentry_operations; | |
839 | ||
840 | dentry->d_fsdata = ino; | |
841 | ino->dentry = dget(dentry); | |
1aff3c8b IK |
842 | atomic_inc(&ino->count); |
843 | p_ino = autofs4_dentry_ino(dentry->d_parent); | |
844 | if (p_ino && dentry->d_parent != dentry) | |
845 | atomic_inc(&p_ino->count); | |
1da177e4 | 846 | ino->inode = inode; |
d8c76e6f | 847 | inc_nlink(dir); |
1da177e4 LT |
848 | dir->i_mtime = CURRENT_TIME; |
849 | ||
850 | return 0; | |
851 | } | |
852 | ||
853 | /* Get/set timeout ioctl() operation */ | |
854 | static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi, | |
855 | unsigned long __user *p) | |
856 | { | |
857 | int rv; | |
858 | unsigned long ntimeout; | |
859 | ||
860 | if ( (rv = get_user(ntimeout, p)) || | |
861 | (rv = put_user(sbi->exp_timeout/HZ, p)) ) | |
862 | return rv; | |
863 | ||
864 | if ( ntimeout > ULONG_MAX/HZ ) | |
865 | sbi->exp_timeout = 0; | |
866 | else | |
867 | sbi->exp_timeout = ntimeout * HZ; | |
868 | ||
869 | return 0; | |
870 | } | |
871 | ||
872 | /* Return protocol version */ | |
873 | static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p) | |
874 | { | |
875 | return put_user(sbi->version, p); | |
876 | } | |
877 | ||
878 | /* Return protocol sub version */ | |
879 | static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p) | |
880 | { | |
881 | return put_user(sbi->sub_version, p); | |
882 | } | |
883 | ||
884 | /* | |
885 | * Tells the daemon whether we need to reghost or not. Also, clears | |
886 | * the reghost_needed flag. | |
887 | */ | |
888 | static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p) | |
889 | { | |
890 | int status; | |
891 | ||
892 | DPRINTK("returning %d", sbi->needs_reghost); | |
893 | ||
894 | status = put_user(sbi->needs_reghost, p); | |
895 | if ( status ) | |
896 | return status; | |
897 | ||
898 | sbi->needs_reghost = 0; | |
899 | return 0; | |
900 | } | |
901 | ||
902 | /* | |
903 | * Enable / Disable reghosting ioctl() operation | |
904 | */ | |
905 | static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p) | |
906 | { | |
907 | int status; | |
908 | int val; | |
909 | ||
910 | status = get_user(val, p); | |
911 | ||
912 | DPRINTK("reghost = %d", val); | |
913 | ||
914 | if (status) | |
915 | return status; | |
916 | ||
917 | /* turn on/off reghosting, with the val */ | |
918 | sbi->reghost_enabled = val; | |
919 | return 0; | |
920 | } | |
921 | ||
922 | /* | |
923 | * Tells the daemon whether it can umount the autofs mount. | |
924 | */ | |
925 | static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) | |
926 | { | |
927 | int status = 0; | |
928 | ||
e3474a8e | 929 | if (may_umount(mnt)) |
1da177e4 LT |
930 | status = 1; |
931 | ||
932 | DPRINTK("returning %d", status); | |
933 | ||
934 | status = put_user(status, p); | |
935 | ||
936 | return status; | |
937 | } | |
938 | ||
939 | /* Identify autofs4_dentries - this is so we can tell if there's | |
940 | an extra dentry refcount or not. We only hold a refcount on the | |
941 | dentry if its non-negative (ie, d_inode != NULL) | |
942 | */ | |
943 | int is_autofs4_dentry(struct dentry *dentry) | |
944 | { | |
945 | return dentry && dentry->d_inode && | |
946 | (dentry->d_op == &autofs4_root_dentry_operations || | |
947 | dentry->d_op == &autofs4_dentry_operations) && | |
948 | dentry->d_fsdata != NULL; | |
949 | } | |
950 | ||
951 | /* | |
952 | * ioctl()'s on the root directory is the chief method for the daemon to | |
953 | * generate kernel reactions | |
954 | */ | |
955 | static int autofs4_root_ioctl(struct inode *inode, struct file *filp, | |
956 | unsigned int cmd, unsigned long arg) | |
957 | { | |
958 | struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); | |
959 | void __user *p = (void __user *)arg; | |
960 | ||
961 | DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u", | |
962 | cmd,arg,sbi,process_group(current)); | |
963 | ||
964 | if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || | |
965 | _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT ) | |
966 | return -ENOTTY; | |
967 | ||
968 | if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) | |
969 | return -EPERM; | |
970 | ||
971 | switch(cmd) { | |
972 | case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ | |
973 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); | |
974 | case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ | |
975 | return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); | |
976 | case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ | |
977 | autofs4_catatonic_mode(sbi); | |
978 | return 0; | |
979 | case AUTOFS_IOC_PROTOVER: /* Get protocol version */ | |
980 | return autofs4_get_protover(sbi, p); | |
981 | case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */ | |
982 | return autofs4_get_protosubver(sbi, p); | |
983 | case AUTOFS_IOC_SETTIMEOUT: | |
984 | return autofs4_get_set_timeout(sbi, p); | |
985 | ||
986 | case AUTOFS_IOC_TOGGLEREGHOST: | |
987 | return autofs4_toggle_reghost(sbi, p); | |
988 | case AUTOFS_IOC_ASKREGHOST: | |
989 | return autofs4_ask_reghost(sbi, p); | |
990 | ||
991 | case AUTOFS_IOC_ASKUMOUNT: | |
a4669ed8 | 992 | return autofs4_ask_umount(filp->f_path.mnt, p); |
1da177e4 LT |
993 | |
994 | /* return a single thing to expire */ | |
995 | case AUTOFS_IOC_EXPIRE: | |
a4669ed8 | 996 | return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
997 | /* same as above, but can send multiple expires through pipe */ |
998 | case AUTOFS_IOC_EXPIRE_MULTI: | |
a4669ed8 | 999 | return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p); |
1da177e4 LT |
1000 | |
1001 | default: | |
1002 | return -ENOSYS; | |
1003 | } | |
1004 | } |