]>
Commit | Line | Data |
---|---|---|
5b88fdd9 SF |
1 | /* |
2 | * Copyright (C) 2005-2016 Junjiro R. Okajima | |
3 | * | |
4 | * This program, aufs is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | /* | |
19 | * inode operations (except add/del/rename) | |
20 | */ | |
21 | ||
22 | #include <linux/device_cgroup.h> | |
23 | #include <linux/fs_stack.h> | |
24 | #include <linux/namei.h> | |
25 | #include <linux/security.h> | |
26 | #include "aufs.h" | |
27 | ||
28 | static int h_permission(struct inode *h_inode, int mask, | |
29 | struct path *h_path, int brperm) | |
30 | { | |
31 | int err; | |
32 | const unsigned char write_mask = !!(mask & (MAY_WRITE | MAY_APPEND)); | |
33 | ||
34 | err = -EPERM; | |
35 | if (write_mask && IS_IMMUTABLE(h_inode)) | |
36 | goto out; | |
37 | ||
38 | err = -EACCES; | |
39 | if (((mask & MAY_EXEC) | |
40 | && S_ISREG(h_inode->i_mode) | |
41 | && (path_noexec(h_path) | |
42 | || !(h_inode->i_mode & S_IXUGO)))) | |
43 | goto out; | |
44 | ||
45 | /* | |
46 | * - skip the lower fs test in the case of write to ro branch. | |
47 | * - nfs dir permission write check is optimized, but a policy for | |
48 | * link/rename requires a real check. | |
49 | * - nfs always sets MS_POSIXACL regardless its mount option 'noacl.' | |
50 | * in this case, generic_permission() returns -EOPNOTSUPP. | |
51 | */ | |
52 | if ((write_mask && !au_br_writable(brperm)) | |
53 | || (au_test_nfs(h_inode->i_sb) && S_ISDIR(h_inode->i_mode) | |
54 | && write_mask && !(mask & MAY_READ)) | |
55 | || !h_inode->i_op->permission) { | |
56 | /* AuLabel(generic_permission); */ | |
57 | /* AuDbg("get_acl %pf\n", h_inode->i_op->get_acl); */ | |
58 | err = generic_permission(h_inode, mask); | |
59 | if (err == -EOPNOTSUPP && au_test_nfs_noacl(h_inode)) | |
60 | err = h_inode->i_op->permission(h_inode, mask); | |
61 | AuTraceErr(err); | |
62 | } else { | |
63 | /* AuLabel(h_inode->permission); */ | |
64 | err = h_inode->i_op->permission(h_inode, mask); | |
65 | AuTraceErr(err); | |
66 | } | |
67 | ||
68 | if (!err) | |
69 | err = devcgroup_inode_permission(h_inode, mask); | |
70 | if (!err) | |
71 | err = security_inode_permission(h_inode, mask); | |
72 | ||
73 | #if 0 | |
74 | if (!err) { | |
75 | /* todo: do we need to call ima_path_check()? */ | |
76 | struct path h_path = { | |
77 | .dentry = | |
78 | .mnt = h_mnt | |
79 | }; | |
80 | err = ima_path_check(&h_path, | |
81 | mask & (MAY_READ | MAY_WRITE | MAY_EXEC), | |
82 | IMA_COUNT_LEAVE); | |
83 | } | |
84 | #endif | |
85 | ||
86 | out: | |
87 | return err; | |
88 | } | |
89 | ||
90 | static int aufs_permission(struct inode *inode, int mask) | |
91 | { | |
92 | int err; | |
93 | aufs_bindex_t bindex, bbot; | |
94 | const unsigned char isdir = !!S_ISDIR(inode->i_mode), | |
95 | write_mask = !!(mask & (MAY_WRITE | MAY_APPEND)); | |
96 | struct inode *h_inode; | |
97 | struct super_block *sb; | |
98 | struct au_branch *br; | |
99 | ||
100 | /* todo: support rcu-walk? */ | |
101 | if (mask & MAY_NOT_BLOCK) | |
102 | return -ECHILD; | |
103 | ||
104 | sb = inode->i_sb; | |
105 | si_read_lock(sb, AuLock_FLUSH); | |
106 | ii_read_lock_child(inode); | |
107 | #if 0 | |
108 | err = au_iigen_test(inode, au_sigen(sb)); | |
109 | if (unlikely(err)) | |
110 | goto out; | |
111 | #endif | |
112 | ||
113 | if (!isdir | |
114 | || write_mask | |
115 | || au_opt_test(au_mntflags(sb), DIRPERM1)) { | |
116 | err = au_busy_or_stale(); | |
117 | h_inode = au_h_iptr(inode, au_ibtop(inode)); | |
118 | if (unlikely(!h_inode | |
119 | || (h_inode->i_mode & S_IFMT) | |
120 | != (inode->i_mode & S_IFMT))) | |
121 | goto out; | |
122 | ||
123 | err = 0; | |
124 | bindex = au_ibtop(inode); | |
125 | br = au_sbr(sb, bindex); | |
126 | err = h_permission(h_inode, mask, &br->br_path, br->br_perm); | |
127 | if (write_mask | |
128 | && !err | |
129 | && !special_file(h_inode->i_mode)) { | |
130 | /* test whether the upper writable branch exists */ | |
131 | err = -EROFS; | |
132 | for (; bindex >= 0; bindex--) | |
133 | if (!au_br_rdonly(au_sbr(sb, bindex))) { | |
134 | err = 0; | |
135 | break; | |
136 | } | |
137 | } | |
138 | goto out; | |
139 | } | |
140 | ||
141 | /* non-write to dir */ | |
142 | err = 0; | |
143 | bbot = au_ibbot(inode); | |
144 | for (bindex = au_ibtop(inode); !err && bindex <= bbot; bindex++) { | |
145 | h_inode = au_h_iptr(inode, bindex); | |
146 | if (h_inode) { | |
147 | err = au_busy_or_stale(); | |
148 | if (unlikely(!S_ISDIR(h_inode->i_mode))) | |
149 | break; | |
150 | ||
151 | br = au_sbr(sb, bindex); | |
152 | err = h_permission(h_inode, mask, &br->br_path, | |
153 | br->br_perm); | |
154 | } | |
155 | } | |
156 | ||
157 | out: | |
158 | ii_read_unlock(inode); | |
159 | si_read_unlock(sb); | |
160 | return err; | |
161 | } | |
162 | ||
163 | /* ---------------------------------------------------------------------- */ | |
164 | ||
165 | static struct dentry *aufs_lookup(struct inode *dir, struct dentry *dentry, | |
166 | unsigned int flags) | |
167 | { | |
168 | struct dentry *ret, *parent; | |
169 | struct inode *inode; | |
170 | struct super_block *sb; | |
171 | int err, npositive; | |
172 | ||
173 | IMustLock(dir); | |
174 | ||
175 | /* todo: support rcu-walk? */ | |
176 | ret = ERR_PTR(-ECHILD); | |
177 | if (flags & LOOKUP_RCU) | |
178 | goto out; | |
179 | ||
180 | ret = ERR_PTR(-ENAMETOOLONG); | |
181 | if (unlikely(dentry->d_name.len > AUFS_MAX_NAMELEN)) | |
182 | goto out; | |
183 | ||
184 | sb = dir->i_sb; | |
185 | err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM); | |
186 | ret = ERR_PTR(err); | |
187 | if (unlikely(err)) | |
188 | goto out; | |
189 | ||
190 | err = au_di_init(dentry); | |
191 | ret = ERR_PTR(err); | |
192 | if (unlikely(err)) | |
193 | goto out_si; | |
194 | ||
195 | inode = NULL; | |
196 | npositive = 0; /* suppress a warning */ | |
197 | parent = dentry->d_parent; /* dir inode is locked */ | |
198 | di_read_lock_parent(parent, AuLock_IR); | |
199 | err = au_alive_dir(parent); | |
200 | if (!err) | |
201 | err = au_digen_test(parent, au_sigen(sb)); | |
202 | if (!err) { | |
203 | /* regardless LOOKUP_CREATE, always ALLOW_NEG */ | |
204 | npositive = au_lkup_dentry(dentry, au_dbtop(parent), | |
205 | AuLkup_ALLOW_NEG); | |
206 | err = npositive; | |
207 | } | |
208 | di_read_unlock(parent, AuLock_IR); | |
209 | ret = ERR_PTR(err); | |
210 | if (unlikely(err < 0)) | |
211 | goto out_unlock; | |
212 | ||
213 | if (npositive) { | |
214 | inode = au_new_inode(dentry, /*must_new*/0); | |
215 | if (IS_ERR(inode)) { | |
216 | ret = (void *)inode; | |
217 | inode = NULL; | |
218 | goto out_unlock; | |
219 | } | |
220 | } | |
221 | ||
222 | if (inode) | |
223 | atomic_inc(&inode->i_count); | |
224 | ret = d_splice_alias(inode, dentry); | |
225 | #if 0 | |
226 | if (unlikely(d_need_lookup(dentry))) { | |
227 | spin_lock(&dentry->d_lock); | |
228 | dentry->d_flags &= ~DCACHE_NEED_LOOKUP; | |
229 | spin_unlock(&dentry->d_lock); | |
230 | } else | |
231 | #endif | |
232 | if (inode) { | |
233 | if (!IS_ERR(ret)) { | |
234 | iput(inode); | |
235 | if (ret && ret != dentry) | |
236 | ii_write_unlock(inode); | |
237 | } else { | |
238 | ii_write_unlock(inode); | |
239 | iput(inode); | |
240 | inode = NULL; | |
241 | } | |
242 | } | |
243 | ||
244 | out_unlock: | |
245 | di_write_unlock(dentry); | |
246 | out_si: | |
247 | si_read_unlock(sb); | |
248 | out: | |
249 | return ret; | |
250 | } | |
251 | ||
252 | /* ---------------------------------------------------------------------- */ | |
253 | ||
254 | struct aopen_node { | |
255 | struct hlist_node hlist; | |
256 | struct file *file, *h_file; | |
257 | }; | |
258 | ||
259 | static int au_do_aopen(struct inode *inode, struct file *file) | |
260 | { | |
261 | struct au_sphlhead *aopen; | |
262 | struct aopen_node *node; | |
263 | struct au_do_open_args args = { | |
264 | .no_lock = 1, | |
265 | .open = au_do_open_nondir | |
266 | }; | |
267 | ||
268 | aopen = &au_sbi(inode->i_sb)->si_aopen; | |
269 | spin_lock(&aopen->spin); | |
270 | hlist_for_each_entry(node, &aopen->head, hlist) | |
271 | if (node->file == file) { | |
272 | args.h_file = node->h_file; | |
273 | break; | |
274 | } | |
275 | spin_unlock(&aopen->spin); | |
276 | /* AuDebugOn(!args.h_file); */ | |
277 | ||
278 | return au_do_open(file, &args); | |
279 | } | |
280 | ||
281 | static int aufs_atomic_open(struct inode *dir, struct dentry *dentry, | |
282 | struct file *file, unsigned int open_flag, | |
283 | umode_t create_mode, int *opened) | |
284 | { | |
285 | int err, h_opened = *opened; | |
286 | unsigned int lkup_flags; | |
287 | struct dentry *parent, *d; | |
288 | struct au_sphlhead *aopen; | |
289 | struct vfsub_aopen_args args = { | |
290 | .open_flag = open_flag, | |
291 | .create_mode = create_mode, | |
292 | .opened = &h_opened | |
293 | }; | |
294 | struct aopen_node aopen_node = { | |
295 | .file = file | |
296 | }; | |
297 | ||
298 | IMustLock(dir); | |
299 | AuDbg("open_flag 0%o\n", open_flag); | |
300 | AuDbgDentry(dentry); | |
301 | ||
302 | err = 0; | |
303 | if (!au_di(dentry)) { | |
304 | lkup_flags = LOOKUP_OPEN; | |
305 | if (open_flag & O_CREAT) | |
306 | lkup_flags |= LOOKUP_CREATE; | |
307 | d = aufs_lookup(dir, dentry, lkup_flags); | |
308 | if (IS_ERR(d)) { | |
309 | err = PTR_ERR(d); | |
310 | AuTraceErr(err); | |
311 | goto out; | |
312 | } else if (d) { | |
313 | /* | |
314 | * obsoleted dentry found. | |
315 | * another error will be returned later. | |
316 | */ | |
317 | d_drop(d); | |
318 | AuDbgDentry(d); | |
319 | dput(d); | |
320 | } | |
321 | AuDbgDentry(dentry); | |
322 | } | |
323 | ||
324 | if (d_is_positive(dentry) | |
325 | || d_unhashed(dentry) | |
326 | || d_unlinked(dentry) | |
327 | || !(open_flag & O_CREAT)) | |
328 | goto out_no_open; | |
329 | ||
330 | err = aufs_read_lock(dentry, AuLock_DW | AuLock_FLUSH | AuLock_GEN); | |
331 | if (unlikely(err)) | |
332 | goto out; | |
333 | ||
334 | parent = dentry->d_parent; /* dir is locked */ | |
335 | di_write_lock_parent(parent); | |
336 | err = au_lkup_dentry(dentry, /*btop*/0, AuLkup_ALLOW_NEG); | |
337 | if (unlikely(err)) | |
338 | goto out_unlock; | |
339 | ||
340 | AuDbgDentry(dentry); | |
341 | if (d_is_positive(dentry)) | |
342 | goto out_unlock; | |
343 | ||
344 | args.file = get_empty_filp(); | |
345 | err = PTR_ERR(args.file); | |
346 | if (IS_ERR(args.file)) | |
347 | goto out_unlock; | |
348 | ||
349 | args.file->f_flags = file->f_flags; | |
350 | err = au_aopen_or_create(dir, dentry, &args); | |
351 | AuTraceErr(err); | |
352 | AuDbgFile(args.file); | |
353 | if (unlikely(err < 0)) { | |
354 | if (h_opened & FILE_OPENED) | |
355 | fput(args.file); | |
356 | else | |
357 | put_filp(args.file); | |
358 | goto out_unlock; | |
359 | } | |
360 | ||
361 | /* some filesystems don't set FILE_CREATED while succeeded? */ | |
362 | *opened |= FILE_CREATED; | |
363 | if (h_opened & FILE_OPENED) | |
364 | aopen_node.h_file = args.file; | |
365 | else { | |
366 | put_filp(args.file); | |
367 | args.file = NULL; | |
368 | } | |
369 | aopen = &au_sbi(dir->i_sb)->si_aopen; | |
370 | au_sphl_add(&aopen_node.hlist, aopen); | |
371 | err = finish_open(file, dentry, au_do_aopen, opened); | |
372 | au_sphl_del(&aopen_node.hlist, aopen); | |
373 | AuTraceErr(err); | |
374 | AuDbgFile(file); | |
375 | if (aopen_node.h_file) | |
376 | fput(aopen_node.h_file); | |
377 | ||
378 | out_unlock: | |
379 | di_write_unlock(parent); | |
380 | aufs_read_unlock(dentry, AuLock_DW); | |
381 | AuDbgDentry(dentry); | |
382 | if (unlikely(err < 0)) | |
383 | goto out; | |
384 | out_no_open: | |
385 | if (err >= 0 && !(*opened & FILE_CREATED)) { | |
386 | AuLabel(out_no_open); | |
387 | dget(dentry); | |
388 | err = finish_no_open(file, dentry); | |
389 | } | |
390 | out: | |
391 | AuDbg("%pd%s%s\n", dentry, | |
392 | (*opened & FILE_CREATED) ? " created" : "", | |
393 | (*opened & FILE_OPENED) ? " opened" : ""); | |
394 | AuTraceErr(err); | |
395 | return err; | |
396 | } | |
397 | ||
398 | ||
399 | /* ---------------------------------------------------------------------- */ | |
400 | ||
401 | static int au_wr_dir_cpup(struct dentry *dentry, struct dentry *parent, | |
402 | const unsigned char add_entry, aufs_bindex_t bcpup, | |
403 | aufs_bindex_t btop) | |
404 | { | |
405 | int err; | |
406 | struct dentry *h_parent; | |
407 | struct inode *h_dir; | |
408 | ||
409 | if (add_entry) | |
410 | IMustLock(d_inode(parent)); | |
411 | else | |
412 | di_write_lock_parent(parent); | |
413 | ||
414 | err = 0; | |
415 | if (!au_h_dptr(parent, bcpup)) { | |
416 | if (btop > bcpup) | |
417 | err = au_cpup_dirs(dentry, bcpup); | |
418 | else if (btop < bcpup) | |
419 | err = au_cpdown_dirs(dentry, bcpup); | |
420 | else | |
421 | BUG(); | |
422 | } | |
423 | if (!err && add_entry && !au_ftest_wrdir(add_entry, TMPFILE)) { | |
424 | h_parent = au_h_dptr(parent, bcpup); | |
425 | h_dir = d_inode(h_parent); | |
426 | inode_lock_nested(h_dir, AuLsc_I_PARENT); | |
427 | err = au_lkup_neg(dentry, bcpup, /*wh*/0); | |
428 | /* todo: no unlock here */ | |
429 | inode_unlock(h_dir); | |
430 | ||
431 | AuDbg("bcpup %d\n", bcpup); | |
432 | if (!err) { | |
433 | if (d_really_is_negative(dentry)) | |
434 | au_set_h_dptr(dentry, btop, NULL); | |
435 | au_update_dbrange(dentry, /*do_put_zero*/0); | |
436 | } | |
437 | } | |
438 | ||
439 | if (!add_entry) | |
440 | di_write_unlock(parent); | |
441 | if (!err) | |
442 | err = bcpup; /* success */ | |
443 | ||
444 | AuTraceErr(err); | |
445 | return err; | |
446 | } | |
447 | ||
448 | /* | |
449 | * decide the branch and the parent dir where we will create a new entry. | |
450 | * returns new bindex or an error. | |
451 | * copyup the parent dir if needed. | |
452 | */ | |
453 | int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry, | |
454 | struct au_wr_dir_args *args) | |
455 | { | |
456 | int err; | |
457 | unsigned int flags; | |
458 | aufs_bindex_t bcpup, btop, src_btop; | |
459 | const unsigned char add_entry | |
460 | = au_ftest_wrdir(args->flags, ADD_ENTRY) | |
461 | | au_ftest_wrdir(args->flags, TMPFILE); | |
462 | struct super_block *sb; | |
463 | struct dentry *parent; | |
464 | struct au_sbinfo *sbinfo; | |
465 | ||
466 | sb = dentry->d_sb; | |
467 | sbinfo = au_sbi(sb); | |
468 | parent = dget_parent(dentry); | |
469 | btop = au_dbtop(dentry); | |
470 | bcpup = btop; | |
471 | if (args->force_btgt < 0) { | |
472 | if (src_dentry) { | |
473 | src_btop = au_dbtop(src_dentry); | |
474 | if (src_btop < btop) | |
475 | bcpup = src_btop; | |
476 | } else if (add_entry) { | |
477 | flags = 0; | |
478 | if (au_ftest_wrdir(args->flags, ISDIR)) | |
479 | au_fset_wbr(flags, DIR); | |
480 | err = AuWbrCreate(sbinfo, dentry, flags); | |
481 | bcpup = err; | |
482 | } | |
483 | ||
484 | if (bcpup < 0 || au_test_ro(sb, bcpup, d_inode(dentry))) { | |
485 | if (add_entry) | |
486 | err = AuWbrCopyup(sbinfo, dentry); | |
487 | else { | |
488 | if (!IS_ROOT(dentry)) { | |
489 | di_read_lock_parent(parent, !AuLock_IR); | |
490 | err = AuWbrCopyup(sbinfo, dentry); | |
491 | di_read_unlock(parent, !AuLock_IR); | |
492 | } else | |
493 | err = AuWbrCopyup(sbinfo, dentry); | |
494 | } | |
495 | bcpup = err; | |
496 | if (unlikely(err < 0)) | |
497 | goto out; | |
498 | } | |
499 | } else { | |
500 | bcpup = args->force_btgt; | |
501 | AuDebugOn(au_test_ro(sb, bcpup, d_inode(dentry))); | |
502 | } | |
503 | ||
504 | AuDbg("btop %d, bcpup %d\n", btop, bcpup); | |
505 | err = bcpup; | |
506 | if (bcpup == btop) | |
507 | goto out; /* success */ | |
508 | ||
509 | /* copyup the new parent into the branch we process */ | |
510 | err = au_wr_dir_cpup(dentry, parent, add_entry, bcpup, btop); | |
511 | if (err >= 0) { | |
512 | if (d_really_is_negative(dentry)) { | |
513 | au_set_h_dptr(dentry, btop, NULL); | |
514 | au_set_dbtop(dentry, bcpup); | |
515 | au_set_dbbot(dentry, bcpup); | |
516 | } | |
517 | AuDebugOn(add_entry | |
518 | && !au_ftest_wrdir(args->flags, TMPFILE) | |
519 | && !au_h_dptr(dentry, bcpup)); | |
520 | } | |
521 | ||
522 | out: | |
523 | dput(parent); | |
524 | return err; | |
525 | } | |
526 | ||
527 | /* ---------------------------------------------------------------------- */ | |
528 | ||
529 | void au_pin_hdir_unlock(struct au_pin *p) | |
530 | { | |
531 | if (p->hdir) | |
532 | au_hn_inode_unlock(p->hdir); | |
533 | } | |
534 | ||
535 | int au_pin_hdir_lock(struct au_pin *p) | |
536 | { | |
537 | int err; | |
538 | ||
539 | err = 0; | |
540 | if (!p->hdir) | |
541 | goto out; | |
542 | ||
543 | /* even if an error happens later, keep this lock */ | |
544 | au_hn_inode_lock_nested(p->hdir, p->lsc_hi); | |
545 | ||
546 | err = -EBUSY; | |
547 | if (unlikely(p->hdir->hi_inode != d_inode(p->h_parent))) | |
548 | goto out; | |
549 | ||
550 | err = 0; | |
551 | if (p->h_dentry) | |
552 | err = au_h_verify(p->h_dentry, p->udba, p->hdir->hi_inode, | |
553 | p->h_parent, p->br); | |
554 | ||
555 | out: | |
556 | return err; | |
557 | } | |
558 | ||
559 | int au_pin_hdir_relock(struct au_pin *p) | |
560 | { | |
561 | int err, i; | |
562 | struct inode *h_i; | |
563 | struct dentry *h_d[] = { | |
564 | p->h_dentry, | |
565 | p->h_parent | |
566 | }; | |
567 | ||
568 | err = au_pin_hdir_lock(p); | |
569 | if (unlikely(err)) | |
570 | goto out; | |
571 | ||
572 | for (i = 0; !err && i < sizeof(h_d)/sizeof(*h_d); i++) { | |
573 | if (!h_d[i]) | |
574 | continue; | |
575 | if (d_is_positive(h_d[i])) { | |
576 | h_i = d_inode(h_d[i]); | |
577 | err = !h_i->i_nlink; | |
578 | } | |
579 | } | |
580 | ||
581 | out: | |
582 | return err; | |
583 | } | |
584 | ||
585 | static void au_pin_hdir_set_owner(struct au_pin *p, struct task_struct *task) | |
586 | { | |
587 | #if !defined(CONFIG_RWSEM_GENERIC_SPINLOCK) && defined(CONFIG_RWSEM_SPIN_ON_OWNER) | |
588 | p->hdir->hi_inode->i_rwsem.owner = task; | |
589 | #endif | |
590 | } | |
591 | ||
592 | void au_pin_hdir_acquire_nest(struct au_pin *p) | |
593 | { | |
594 | if (p->hdir) { | |
595 | rwsem_acquire_nest(&p->hdir->hi_inode->i_rwsem.dep_map, | |
596 | p->lsc_hi, 0, NULL, _RET_IP_); | |
597 | au_pin_hdir_set_owner(p, current); | |
598 | } | |
599 | } | |
600 | ||
601 | void au_pin_hdir_release(struct au_pin *p) | |
602 | { | |
603 | if (p->hdir) { | |
604 | au_pin_hdir_set_owner(p, p->task); | |
605 | rwsem_release(&p->hdir->hi_inode->i_rwsem.dep_map, 1, _RET_IP_); | |
606 | } | |
607 | } | |
608 | ||
609 | struct dentry *au_pinned_h_parent(struct au_pin *pin) | |
610 | { | |
611 | if (pin && pin->parent) | |
612 | return au_h_dptr(pin->parent, pin->bindex); | |
613 | return NULL; | |
614 | } | |
615 | ||
616 | void au_unpin(struct au_pin *p) | |
617 | { | |
618 | if (p->hdir) | |
619 | au_pin_hdir_unlock(p); | |
620 | if (p->h_mnt && au_ftest_pin(p->flags, MNT_WRITE)) | |
621 | vfsub_mnt_drop_write(p->h_mnt); | |
622 | if (!p->hdir) | |
623 | return; | |
624 | ||
625 | if (!au_ftest_pin(p->flags, DI_LOCKED)) | |
626 | di_read_unlock(p->parent, AuLock_IR); | |
627 | iput(p->hdir->hi_inode); | |
628 | dput(p->parent); | |
629 | p->parent = NULL; | |
630 | p->hdir = NULL; | |
631 | p->h_mnt = NULL; | |
632 | /* do not clear p->task */ | |
633 | } | |
634 | ||
635 | int au_do_pin(struct au_pin *p) | |
636 | { | |
637 | int err; | |
638 | struct super_block *sb; | |
639 | struct inode *h_dir; | |
640 | ||
641 | err = 0; | |
642 | sb = p->dentry->d_sb; | |
643 | p->br = au_sbr(sb, p->bindex); | |
644 | if (IS_ROOT(p->dentry)) { | |
645 | if (au_ftest_pin(p->flags, MNT_WRITE)) { | |
646 | p->h_mnt = au_br_mnt(p->br); | |
647 | err = vfsub_mnt_want_write(p->h_mnt); | |
648 | if (unlikely(err)) { | |
649 | au_fclr_pin(p->flags, MNT_WRITE); | |
650 | goto out_err; | |
651 | } | |
652 | } | |
653 | goto out; | |
654 | } | |
655 | ||
656 | p->h_dentry = NULL; | |
657 | if (p->bindex <= au_dbbot(p->dentry)) | |
658 | p->h_dentry = au_h_dptr(p->dentry, p->bindex); | |
659 | ||
660 | p->parent = dget_parent(p->dentry); | |
661 | if (!au_ftest_pin(p->flags, DI_LOCKED)) | |
662 | di_read_lock(p->parent, AuLock_IR, p->lsc_di); | |
663 | ||
664 | h_dir = NULL; | |
665 | p->h_parent = au_h_dptr(p->parent, p->bindex); | |
666 | p->hdir = au_hi(d_inode(p->parent), p->bindex); | |
667 | if (p->hdir) | |
668 | h_dir = p->hdir->hi_inode; | |
669 | ||
670 | /* | |
671 | * udba case, or | |
672 | * if DI_LOCKED is not set, then p->parent may be different | |
673 | * and h_parent can be NULL. | |
674 | */ | |
675 | if (unlikely(!p->hdir || !h_dir || !p->h_parent)) { | |
676 | err = -EBUSY; | |
677 | if (!au_ftest_pin(p->flags, DI_LOCKED)) | |
678 | di_read_unlock(p->parent, AuLock_IR); | |
679 | dput(p->parent); | |
680 | p->parent = NULL; | |
681 | goto out_err; | |
682 | } | |
683 | ||
684 | if (au_ftest_pin(p->flags, MNT_WRITE)) { | |
685 | p->h_mnt = au_br_mnt(p->br); | |
686 | err = vfsub_mnt_want_write(p->h_mnt); | |
687 | if (unlikely(err)) { | |
688 | au_fclr_pin(p->flags, MNT_WRITE); | |
689 | if (!au_ftest_pin(p->flags, DI_LOCKED)) | |
690 | di_read_unlock(p->parent, AuLock_IR); | |
691 | dput(p->parent); | |
692 | p->parent = NULL; | |
693 | goto out_err; | |
694 | } | |
695 | } | |
696 | ||
697 | au_igrab(h_dir); | |
698 | err = au_pin_hdir_lock(p); | |
699 | if (!err) | |
700 | goto out; /* success */ | |
701 | ||
702 | au_unpin(p); | |
703 | ||
704 | out_err: | |
705 | pr_err("err %d\n", err); | |
706 | err = au_busy_or_stale(); | |
707 | out: | |
708 | return err; | |
709 | } | |
710 | ||
711 | void au_pin_init(struct au_pin *p, struct dentry *dentry, | |
712 | aufs_bindex_t bindex, int lsc_di, int lsc_hi, | |
713 | unsigned int udba, unsigned char flags) | |
714 | { | |
715 | p->dentry = dentry; | |
716 | p->udba = udba; | |
717 | p->lsc_di = lsc_di; | |
718 | p->lsc_hi = lsc_hi; | |
719 | p->flags = flags; | |
720 | p->bindex = bindex; | |
721 | ||
722 | p->parent = NULL; | |
723 | p->hdir = NULL; | |
724 | p->h_mnt = NULL; | |
725 | ||
726 | p->h_dentry = NULL; | |
727 | p->h_parent = NULL; | |
728 | p->br = NULL; | |
729 | p->task = current; | |
730 | } | |
731 | ||
732 | int au_pin(struct au_pin *pin, struct dentry *dentry, aufs_bindex_t bindex, | |
733 | unsigned int udba, unsigned char flags) | |
734 | { | |
735 | au_pin_init(pin, dentry, bindex, AuLsc_DI_PARENT, AuLsc_I_PARENT2, | |
736 | udba, flags); | |
737 | return au_do_pin(pin); | |
738 | } | |
739 | ||
740 | /* ---------------------------------------------------------------------- */ | |
741 | ||
742 | /* | |
743 | * ->setattr() and ->getattr() are called in various cases. | |
744 | * chmod, stat: dentry is revalidated. | |
745 | * fchmod, fstat: file and dentry are not revalidated, additionally they may be | |
746 | * unhashed. | |
747 | * for ->setattr(), ia->ia_file is passed from ftruncate only. | |
748 | */ | |
749 | /* todo: consolidate with do_refresh() and simple_reval_dpath() */ | |
750 | int au_reval_for_attr(struct dentry *dentry, unsigned int sigen) | |
751 | { | |
752 | int err; | |
753 | struct dentry *parent; | |
754 | ||
755 | err = 0; | |
756 | if (au_digen_test(dentry, sigen)) { | |
757 | parent = dget_parent(dentry); | |
758 | di_read_lock_parent(parent, AuLock_IR); | |
759 | err = au_refresh_dentry(dentry, parent); | |
760 | di_read_unlock(parent, AuLock_IR); | |
761 | dput(parent); | |
762 | } | |
763 | ||
764 | AuTraceErr(err); | |
765 | return err; | |
766 | } | |
767 | ||
768 | int au_pin_and_icpup(struct dentry *dentry, struct iattr *ia, | |
769 | struct au_icpup_args *a) | |
770 | { | |
771 | int err; | |
772 | loff_t sz; | |
773 | aufs_bindex_t btop, ibtop; | |
774 | struct dentry *hi_wh, *parent; | |
775 | struct inode *inode; | |
776 | struct au_wr_dir_args wr_dir_args = { | |
777 | .force_btgt = -1, | |
778 | .flags = 0 | |
779 | }; | |
780 | ||
781 | if (d_is_dir(dentry)) | |
782 | au_fset_wrdir(wr_dir_args.flags, ISDIR); | |
783 | /* plink or hi_wh() case */ | |
784 | btop = au_dbtop(dentry); | |
785 | inode = d_inode(dentry); | |
786 | ibtop = au_ibtop(inode); | |
787 | if (btop != ibtop && !au_test_ro(inode->i_sb, ibtop, inode)) | |
788 | wr_dir_args.force_btgt = ibtop; | |
789 | err = au_wr_dir(dentry, /*src_dentry*/NULL, &wr_dir_args); | |
790 | if (unlikely(err < 0)) | |
791 | goto out; | |
792 | a->btgt = err; | |
793 | if (err != btop) | |
794 | au_fset_icpup(a->flags, DID_CPUP); | |
795 | ||
796 | err = 0; | |
797 | a->pin_flags = AuPin_MNT_WRITE; | |
798 | parent = NULL; | |
799 | if (!IS_ROOT(dentry)) { | |
800 | au_fset_pin(a->pin_flags, DI_LOCKED); | |
801 | parent = dget_parent(dentry); | |
802 | di_write_lock_parent(parent); | |
803 | } | |
804 | ||
805 | err = au_pin(&a->pin, dentry, a->btgt, a->udba, a->pin_flags); | |
806 | if (unlikely(err)) | |
807 | goto out_parent; | |
808 | ||
809 | sz = -1; | |
810 | a->h_path.dentry = au_h_dptr(dentry, btop); | |
811 | a->h_inode = d_inode(a->h_path.dentry); | |
812 | if (ia && (ia->ia_valid & ATTR_SIZE)) { | |
813 | inode_lock_nested(a->h_inode, AuLsc_I_CHILD); | |
814 | if (ia->ia_size < i_size_read(a->h_inode)) | |
815 | sz = ia->ia_size; | |
816 | inode_unlock(a->h_inode); | |
817 | } | |
818 | ||
819 | hi_wh = NULL; | |
820 | if (au_ftest_icpup(a->flags, DID_CPUP) && d_unlinked(dentry)) { | |
821 | hi_wh = au_hi_wh(inode, a->btgt); | |
822 | if (!hi_wh) { | |
823 | struct au_cp_generic cpg = { | |
824 | .dentry = dentry, | |
825 | .bdst = a->btgt, | |
826 | .bsrc = -1, | |
827 | .len = sz, | |
828 | .pin = &a->pin | |
829 | }; | |
830 | err = au_sio_cpup_wh(&cpg, /*file*/NULL); | |
831 | if (unlikely(err)) | |
832 | goto out_unlock; | |
833 | hi_wh = au_hi_wh(inode, a->btgt); | |
834 | /* todo: revalidate hi_wh? */ | |
835 | } | |
836 | } | |
837 | ||
838 | if (parent) { | |
839 | au_pin_set_parent_lflag(&a->pin, /*lflag*/0); | |
840 | di_downgrade_lock(parent, AuLock_IR); | |
841 | dput(parent); | |
842 | parent = NULL; | |
843 | } | |
844 | if (!au_ftest_icpup(a->flags, DID_CPUP)) | |
845 | goto out; /* success */ | |
846 | ||
847 | if (!d_unhashed(dentry)) { | |
848 | struct au_cp_generic cpg = { | |
849 | .dentry = dentry, | |
850 | .bdst = a->btgt, | |
851 | .bsrc = btop, | |
852 | .len = sz, | |
853 | .pin = &a->pin, | |
854 | .flags = AuCpup_DTIME | AuCpup_HOPEN | |
855 | }; | |
856 | err = au_sio_cpup_simple(&cpg); | |
857 | if (!err) | |
858 | a->h_path.dentry = au_h_dptr(dentry, a->btgt); | |
859 | } else if (!hi_wh) | |
860 | a->h_path.dentry = au_h_dptr(dentry, a->btgt); | |
861 | else | |
862 | a->h_path.dentry = hi_wh; /* do not dget here */ | |
863 | ||
864 | out_unlock: | |
865 | a->h_inode = d_inode(a->h_path.dentry); | |
866 | if (!err) | |
867 | goto out; /* success */ | |
868 | au_unpin(&a->pin); | |
869 | out_parent: | |
870 | if (parent) { | |
871 | di_write_unlock(parent); | |
872 | dput(parent); | |
873 | } | |
874 | out: | |
875 | if (!err) | |
876 | inode_lock_nested(a->h_inode, AuLsc_I_CHILD); | |
877 | return err; | |
878 | } | |
879 | ||
880 | static int aufs_setattr(struct dentry *dentry, struct iattr *ia) | |
881 | { | |
882 | int err; | |
883 | struct inode *inode, *delegated; | |
884 | struct super_block *sb; | |
885 | struct file *file; | |
886 | struct au_icpup_args *a; | |
887 | ||
888 | inode = d_inode(dentry); | |
889 | IMustLock(inode); | |
890 | ||
bff40b16 O |
891 | err = setattr_prepare(dentry, ia); |
892 | if (unlikely(err)) | |
893 | goto out; | |
894 | ||
5b88fdd9 SF |
895 | err = -ENOMEM; |
896 | a = kzalloc(sizeof(*a), GFP_NOFS); | |
897 | if (unlikely(!a)) | |
898 | goto out; | |
899 | ||
900 | if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID)) | |
901 | ia->ia_valid &= ~ATTR_MODE; | |
902 | ||
903 | file = NULL; | |
904 | sb = dentry->d_sb; | |
905 | err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM); | |
906 | if (unlikely(err)) | |
907 | goto out_kfree; | |
908 | ||
909 | if (ia->ia_valid & ATTR_FILE) { | |
910 | /* currently ftruncate(2) only */ | |
911 | AuDebugOn(!d_is_reg(dentry)); | |
912 | file = ia->ia_file; | |
913 | err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1); | |
914 | if (unlikely(err)) | |
915 | goto out_si; | |
916 | ia->ia_file = au_hf_top(file); | |
917 | a->udba = AuOpt_UDBA_NONE; | |
918 | } else { | |
919 | /* fchmod() doesn't pass ia_file */ | |
920 | a->udba = au_opt_udba(sb); | |
921 | di_write_lock_child(dentry); | |
922 | /* no d_unlinked(), to set UDBA_NONE for root */ | |
923 | if (d_unhashed(dentry)) | |
924 | a->udba = AuOpt_UDBA_NONE; | |
925 | if (a->udba != AuOpt_UDBA_NONE) { | |
926 | AuDebugOn(IS_ROOT(dentry)); | |
927 | err = au_reval_for_attr(dentry, au_sigen(sb)); | |
928 | if (unlikely(err)) | |
929 | goto out_dentry; | |
930 | } | |
931 | } | |
932 | ||
933 | err = au_pin_and_icpup(dentry, ia, a); | |
934 | if (unlikely(err < 0)) | |
935 | goto out_dentry; | |
936 | if (au_ftest_icpup(a->flags, DID_CPUP)) { | |
937 | ia->ia_file = NULL; | |
938 | ia->ia_valid &= ~ATTR_FILE; | |
939 | } | |
940 | ||
941 | a->h_path.mnt = au_sbr_mnt(sb, a->btgt); | |
942 | if ((ia->ia_valid & (ATTR_MODE | ATTR_CTIME)) | |
943 | == (ATTR_MODE | ATTR_CTIME)) { | |
944 | err = security_path_chmod(&a->h_path, ia->ia_mode); | |
945 | if (unlikely(err)) | |
946 | goto out_unlock; | |
947 | } else if ((ia->ia_valid & (ATTR_UID | ATTR_GID)) | |
948 | && (ia->ia_valid & ATTR_CTIME)) { | |
949 | err = security_path_chown(&a->h_path, ia->ia_uid, ia->ia_gid); | |
950 | if (unlikely(err)) | |
951 | goto out_unlock; | |
952 | } | |
953 | ||
954 | if (ia->ia_valid & ATTR_SIZE) { | |
955 | struct file *f; | |
956 | ||
957 | if (ia->ia_size < i_size_read(inode)) | |
958 | /* unmap only */ | |
959 | truncate_setsize(inode, ia->ia_size); | |
960 | ||
961 | f = NULL; | |
962 | if (ia->ia_valid & ATTR_FILE) | |
963 | f = ia->ia_file; | |
964 | inode_unlock(a->h_inode); | |
965 | err = vfsub_trunc(&a->h_path, ia->ia_size, ia->ia_valid, f); | |
966 | inode_lock_nested(a->h_inode, AuLsc_I_CHILD); | |
967 | } else { | |
968 | delegated = NULL; | |
969 | while (1) { | |
970 | err = vfsub_notify_change(&a->h_path, ia, &delegated); | |
971 | if (delegated) { | |
972 | err = break_deleg_wait(&delegated); | |
973 | if (!err) | |
974 | continue; | |
975 | } | |
976 | break; | |
977 | } | |
978 | } | |
979 | /* | |
980 | * regardless aufs 'acl' option setting. | |
981 | * why don't all acl-aware fs call this func from their ->setattr()? | |
982 | */ | |
983 | if (!err && (ia->ia_valid & ATTR_MODE)) | |
984 | err = vfsub_acl_chmod(a->h_inode, ia->ia_mode); | |
985 | if (!err) | |
986 | au_cpup_attr_changeable(inode); | |
987 | ||
988 | out_unlock: | |
989 | inode_unlock(a->h_inode); | |
990 | au_unpin(&a->pin); | |
991 | if (unlikely(err)) | |
992 | au_update_dbtop(dentry); | |
993 | out_dentry: | |
994 | di_write_unlock(dentry); | |
995 | if (file) { | |
996 | fi_write_unlock(file); | |
997 | ia->ia_file = file; | |
998 | ia->ia_valid |= ATTR_FILE; | |
999 | } | |
1000 | out_si: | |
1001 | si_read_unlock(sb); | |
1002 | out_kfree: | |
1003 | au_delayed_kfree(a); | |
1004 | out: | |
1005 | AuTraceErr(err); | |
1006 | return err; | |
1007 | } | |
1008 | ||
1009 | #if IS_ENABLED(CONFIG_AUFS_XATTR) || IS_ENABLED(CONFIG_FS_POSIX_ACL) | |
1010 | static int au_h_path_to_set_attr(struct dentry *dentry, | |
1011 | struct au_icpup_args *a, struct path *h_path) | |
1012 | { | |
1013 | int err; | |
1014 | struct super_block *sb; | |
1015 | ||
1016 | sb = dentry->d_sb; | |
1017 | a->udba = au_opt_udba(sb); | |
1018 | /* no d_unlinked(), to set UDBA_NONE for root */ | |
1019 | if (d_unhashed(dentry)) | |
1020 | a->udba = AuOpt_UDBA_NONE; | |
1021 | if (a->udba != AuOpt_UDBA_NONE) { | |
1022 | AuDebugOn(IS_ROOT(dentry)); | |
1023 | err = au_reval_for_attr(dentry, au_sigen(sb)); | |
1024 | if (unlikely(err)) | |
1025 | goto out; | |
1026 | } | |
1027 | err = au_pin_and_icpup(dentry, /*ia*/NULL, a); | |
1028 | if (unlikely(err < 0)) | |
1029 | goto out; | |
1030 | ||
1031 | h_path->dentry = a->h_path.dentry; | |
1032 | h_path->mnt = au_sbr_mnt(sb, a->btgt); | |
1033 | ||
1034 | out: | |
1035 | return err; | |
1036 | } | |
1037 | ||
1038 | ssize_t au_srxattr(struct dentry *dentry, struct inode *inode, | |
1039 | struct au_srxattr *arg) | |
1040 | { | |
1041 | int err; | |
1042 | struct path h_path; | |
1043 | struct super_block *sb; | |
1044 | struct au_icpup_args *a; | |
1045 | struct inode *h_inode; | |
1046 | ||
1047 | IMustLock(inode); | |
1048 | ||
1049 | err = -ENOMEM; | |
1050 | a = kzalloc(sizeof(*a), GFP_NOFS); | |
1051 | if (unlikely(!a)) | |
1052 | goto out; | |
1053 | ||
1054 | sb = dentry->d_sb; | |
1055 | err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM); | |
1056 | if (unlikely(err)) | |
1057 | goto out_kfree; | |
1058 | ||
1059 | h_path.dentry = NULL; /* silence gcc */ | |
1060 | di_write_lock_child(dentry); | |
1061 | err = au_h_path_to_set_attr(dentry, a, &h_path); | |
1062 | if (unlikely(err)) | |
1063 | goto out_di; | |
1064 | ||
1065 | inode_unlock(a->h_inode); | |
1066 | switch (arg->type) { | |
1067 | case AU_XATTR_SET: | |
1068 | AuDebugOn(d_is_negative(h_path.dentry)); | |
1069 | err = vfsub_setxattr(h_path.dentry, | |
1070 | arg->u.set.name, arg->u.set.value, | |
1071 | arg->u.set.size, arg->u.set.flags); | |
1072 | break; | |
1073 | case AU_XATTR_REMOVE: | |
1074 | err = vfsub_removexattr(h_path.dentry, arg->u.remove.name); | |
1075 | break; | |
1076 | case AU_ACL_SET: | |
1077 | err = -EOPNOTSUPP; | |
1078 | h_inode = d_inode(h_path.dentry); | |
1079 | if (h_inode->i_op->set_acl) | |
1080 | err = h_inode->i_op->set_acl(h_inode, | |
1081 | arg->u.acl_set.acl, | |
1082 | arg->u.acl_set.type); | |
1083 | break; | |
1084 | } | |
1085 | if (!err) | |
1086 | au_cpup_attr_timesizes(inode); | |
1087 | ||
1088 | au_unpin(&a->pin); | |
1089 | if (unlikely(err)) | |
1090 | au_update_dbtop(dentry); | |
1091 | ||
1092 | out_di: | |
1093 | di_write_unlock(dentry); | |
1094 | si_read_unlock(sb); | |
1095 | out_kfree: | |
1096 | au_delayed_kfree(a); | |
1097 | out: | |
1098 | AuTraceErr(err); | |
1099 | return err; | |
1100 | } | |
1101 | #endif | |
1102 | ||
1103 | static void au_refresh_iattr(struct inode *inode, struct kstat *st, | |
1104 | unsigned int nlink) | |
1105 | { | |
1106 | unsigned int n; | |
1107 | ||
1108 | inode->i_mode = st->mode; | |
1109 | /* don't i_[ug]id_write() here */ | |
1110 | inode->i_uid = st->uid; | |
1111 | inode->i_gid = st->gid; | |
1112 | inode->i_atime = st->atime; | |
1113 | inode->i_mtime = st->mtime; | |
1114 | inode->i_ctime = st->ctime; | |
1115 | ||
1116 | au_cpup_attr_nlink(inode, /*force*/0); | |
1117 | if (S_ISDIR(inode->i_mode)) { | |
1118 | n = inode->i_nlink; | |
1119 | n -= nlink; | |
1120 | n += st->nlink; | |
1121 | smp_mb(); /* for i_nlink */ | |
1122 | /* 0 can happen */ | |
1123 | set_nlink(inode, n); | |
1124 | } | |
1125 | ||
1126 | spin_lock(&inode->i_lock); | |
1127 | inode->i_blocks = st->blocks; | |
1128 | i_size_write(inode, st->size); | |
1129 | spin_unlock(&inode->i_lock); | |
1130 | } | |
1131 | ||
1132 | /* | |
1133 | * common routine for aufs_getattr() and aufs_getxattr(). | |
1134 | * returns zero or negative (an error). | |
1135 | * @dentry will be read-locked in success. | |
1136 | */ | |
1137 | int au_h_path_getattr(struct dentry *dentry, int force, struct path *h_path) | |
1138 | { | |
1139 | int err; | |
1140 | unsigned int mnt_flags, sigen; | |
1141 | unsigned char udba_none; | |
1142 | aufs_bindex_t bindex; | |
1143 | struct super_block *sb, *h_sb; | |
1144 | struct inode *inode; | |
1145 | ||
1146 | h_path->mnt = NULL; | |
1147 | h_path->dentry = NULL; | |
1148 | ||
1149 | err = 0; | |
1150 | sb = dentry->d_sb; | |
1151 | mnt_flags = au_mntflags(sb); | |
1152 | udba_none = !!au_opt_test(mnt_flags, UDBA_NONE); | |
1153 | ||
1154 | /* support fstat(2) */ | |
1155 | if (!d_unlinked(dentry) && !udba_none) { | |
1156 | sigen = au_sigen(sb); | |
1157 | err = au_digen_test(dentry, sigen); | |
1158 | if (!err) { | |
1159 | di_read_lock_child(dentry, AuLock_IR); | |
1160 | err = au_dbrange_test(dentry); | |
1161 | if (unlikely(err)) { | |
1162 | di_read_unlock(dentry, AuLock_IR); | |
1163 | goto out; | |
1164 | } | |
1165 | } else { | |
1166 | AuDebugOn(IS_ROOT(dentry)); | |
1167 | di_write_lock_child(dentry); | |
1168 | err = au_dbrange_test(dentry); | |
1169 | if (!err) | |
1170 | err = au_reval_for_attr(dentry, sigen); | |
1171 | if (!err) | |
1172 | di_downgrade_lock(dentry, AuLock_IR); | |
1173 | else { | |
1174 | di_write_unlock(dentry); | |
1175 | goto out; | |
1176 | } | |
1177 | } | |
1178 | } else | |
1179 | di_read_lock_child(dentry, AuLock_IR); | |
1180 | ||
1181 | inode = d_inode(dentry); | |
1182 | bindex = au_ibtop(inode); | |
1183 | h_path->mnt = au_sbr_mnt(sb, bindex); | |
1184 | h_sb = h_path->mnt->mnt_sb; | |
1185 | if (!force | |
1186 | && !au_test_fs_bad_iattr(h_sb) | |
1187 | && udba_none) | |
1188 | goto out; /* success */ | |
1189 | ||
1190 | if (au_dbtop(dentry) == bindex) | |
1191 | h_path->dentry = au_h_dptr(dentry, bindex); | |
1192 | else if (au_opt_test(mnt_flags, PLINK) && au_plink_test(inode)) { | |
1193 | h_path->dentry = au_plink_lkup(inode, bindex); | |
1194 | if (IS_ERR(h_path->dentry)) | |
1195 | /* pretending success */ | |
1196 | h_path->dentry = NULL; | |
1197 | else | |
1198 | dput(h_path->dentry); | |
1199 | } | |
1200 | ||
1201 | out: | |
1202 | return err; | |
1203 | } | |
1204 | ||
1205 | static int aufs_getattr(struct vfsmount *mnt __maybe_unused, | |
1206 | struct dentry *dentry, struct kstat *st) | |
1207 | { | |
1208 | int err; | |
1209 | unsigned char positive; | |
1210 | struct path h_path; | |
1211 | struct inode *inode; | |
1212 | struct super_block *sb; | |
1213 | ||
1214 | inode = d_inode(dentry); | |
1215 | sb = dentry->d_sb; | |
1216 | err = si_read_lock(sb, AuLock_FLUSH | AuLock_NOPLM); | |
1217 | if (unlikely(err)) | |
1218 | goto out; | |
1219 | err = au_h_path_getattr(dentry, /*force*/0, &h_path); | |
1220 | if (unlikely(err)) | |
1221 | goto out_si; | |
1222 | if (unlikely(!h_path.dentry)) | |
1223 | /* illegally overlapped or something */ | |
1224 | goto out_fill; /* pretending success */ | |
1225 | ||
1226 | positive = d_is_positive(h_path.dentry); | |
1227 | if (positive) | |
1228 | err = vfs_getattr(&h_path, st); | |
1229 | if (!err) { | |
1230 | if (positive) | |
1231 | au_refresh_iattr(inode, st, | |
1232 | d_inode(h_path.dentry)->i_nlink); | |
1233 | goto out_fill; /* success */ | |
1234 | } | |
1235 | AuTraceErr(err); | |
1236 | goto out_di; | |
1237 | ||
1238 | out_fill: | |
1239 | generic_fillattr(inode, st); | |
1240 | out_di: | |
1241 | di_read_unlock(dentry, AuLock_IR); | |
1242 | out_si: | |
1243 | si_read_unlock(sb); | |
1244 | out: | |
1245 | AuTraceErr(err); | |
1246 | return err; | |
1247 | } | |
1248 | ||
1249 | /* ---------------------------------------------------------------------- */ | |
1250 | ||
1251 | static const char *aufs_get_link(struct dentry *dentry, struct inode *inode, | |
1252 | struct delayed_call *done) | |
1253 | { | |
1254 | const char *ret; | |
1255 | struct dentry *h_dentry; | |
1256 | struct inode *h_inode; | |
1257 | int err; | |
1258 | aufs_bindex_t bindex; | |
1259 | ||
1260 | ret = NULL; /* suppress a warning */ | |
1261 | err = -ECHILD; | |
1262 | if (!dentry) | |
1263 | goto out; | |
1264 | ||
1265 | err = aufs_read_lock(dentry, AuLock_IR | AuLock_GEN); | |
1266 | if (unlikely(err)) | |
1267 | goto out; | |
1268 | ||
1269 | err = au_d_hashed_positive(dentry); | |
1270 | if (unlikely(err)) | |
1271 | goto out_unlock; | |
1272 | ||
1273 | err = -EINVAL; | |
1274 | inode = d_inode(dentry); | |
1275 | bindex = au_ibtop(inode); | |
1276 | h_inode = au_h_iptr(inode, bindex); | |
1277 | if (unlikely(!h_inode->i_op->get_link)) | |
1278 | goto out_unlock; | |
1279 | ||
1280 | err = -EBUSY; | |
1281 | h_dentry = NULL; | |
1282 | if (au_dbtop(dentry) <= bindex) { | |
1283 | h_dentry = au_h_dptr(dentry, bindex); | |
1284 | if (h_dentry) | |
1285 | dget(h_dentry); | |
1286 | } | |
1287 | if (!h_dentry) { | |
1288 | h_dentry = d_find_any_alias(h_inode); | |
1289 | if (IS_ERR(h_dentry)) { | |
1290 | err = PTR_ERR(h_dentry); | |
1291 | goto out_unlock; | |
1292 | } | |
1293 | } | |
1294 | if (unlikely(!h_dentry)) | |
1295 | goto out_unlock; | |
1296 | ||
1297 | err = 0; | |
1298 | AuDbg("%pf\n", h_inode->i_op->get_link); | |
1299 | AuDbgDentry(h_dentry); | |
1300 | ret = h_inode->i_op->get_link(h_dentry, h_inode, done); | |
1301 | dput(h_dentry); | |
1302 | if (IS_ERR(ret)) | |
1303 | err = PTR_ERR(ret); | |
1304 | ||
1305 | out_unlock: | |
1306 | aufs_read_unlock(dentry, AuLock_IR); | |
1307 | out: | |
1308 | if (unlikely(err)) | |
1309 | ret = ERR_PTR(err); | |
1310 | AuTraceErrPtr(ret); | |
1311 | return ret; | |
1312 | } | |
1313 | ||
1314 | /* ---------------------------------------------------------------------- */ | |
1315 | ||
1316 | static int au_is_special(struct inode *inode) | |
1317 | { | |
1318 | return (inode->i_mode & (S_IFBLK | S_IFCHR | S_IFIFO | S_IFSOCK)); | |
1319 | } | |
1320 | ||
1321 | static int aufs_update_time(struct inode *inode, struct timespec *ts, int flags) | |
1322 | { | |
1323 | int err; | |
1324 | aufs_bindex_t bindex; | |
1325 | struct super_block *sb; | |
1326 | struct inode *h_inode; | |
1327 | struct vfsmount *h_mnt; | |
1328 | ||
1329 | sb = inode->i_sb; | |
1330 | WARN_ONCE((flags & S_ATIME) && !IS_NOATIME(inode), | |
1331 | "unexpected s_flags 0x%lx", sb->s_flags); | |
1332 | ||
1333 | /* mmap_sem might be acquired already, cf. aufs_mmap() */ | |
1334 | lockdep_off(); | |
1335 | si_read_lock(sb, AuLock_FLUSH); | |
1336 | ii_write_lock_child(inode); | |
1337 | lockdep_on(); | |
1338 | ||
1339 | err = 0; | |
1340 | bindex = au_ibtop(inode); | |
1341 | h_inode = au_h_iptr(inode, bindex); | |
1342 | if (!au_test_ro(sb, bindex, inode)) { | |
1343 | h_mnt = au_sbr_mnt(sb, bindex); | |
1344 | err = vfsub_mnt_want_write(h_mnt); | |
1345 | if (!err) { | |
1346 | err = vfsub_update_time(h_inode, ts, flags); | |
1347 | vfsub_mnt_drop_write(h_mnt); | |
1348 | } | |
1349 | } else if (au_is_special(h_inode)) { | |
1350 | /* | |
1351 | * Never copy-up here. | |
1352 | * These special files may already be opened and used for | |
1353 | * communicating. If we copied it up, then the communication | |
1354 | * would be corrupted. | |
1355 | */ | |
1356 | AuWarn1("timestamps for i%lu are ignored " | |
1357 | "since it is on readonly branch (hi%lu).\n", | |
1358 | inode->i_ino, h_inode->i_ino); | |
1359 | } else if (flags & ~S_ATIME) { | |
1360 | err = -EIO; | |
1361 | AuIOErr1("unexpected flags 0x%x\n", flags); | |
1362 | AuDebugOn(1); | |
1363 | } | |
1364 | ||
1365 | lockdep_off(); | |
1366 | if (!err) | |
1367 | au_cpup_attr_timesizes(inode); | |
1368 | ii_write_unlock(inode); | |
1369 | si_read_unlock(sb); | |
1370 | lockdep_on(); | |
1371 | ||
1372 | if (!err && (flags & S_VERSION)) | |
1373 | inode_inc_iversion(inode); | |
1374 | ||
1375 | return err; | |
1376 | } | |
1377 | ||
1378 | /* ---------------------------------------------------------------------- */ | |
1379 | ||
1380 | /* no getattr version will be set by module.c:aufs_init() */ | |
1381 | struct inode_operations aufs_iop_nogetattr[AuIop_Last], | |
1382 | aufs_iop[] = { | |
1383 | [AuIop_SYMLINK] = { | |
1384 | .permission = aufs_permission, | |
1385 | #ifdef CONFIG_FS_POSIX_ACL | |
1386 | .get_acl = aufs_get_acl, | |
1387 | .set_acl = aufs_set_acl, /* unsupport for symlink? */ | |
1388 | #endif | |
1389 | ||
1390 | .setattr = aufs_setattr, | |
1391 | .getattr = aufs_getattr, | |
1392 | ||
1393 | #ifdef CONFIG_AUFS_XATTR | |
5b88fdd9 | 1394 | .listxattr = aufs_listxattr, |
5b88fdd9 SF |
1395 | #endif |
1396 | ||
1397 | .readlink = generic_readlink, | |
1398 | .get_link = aufs_get_link, | |
1399 | ||
1400 | /* .update_time = aufs_update_time */ | |
1401 | }, | |
1402 | [AuIop_DIR] = { | |
1403 | .create = aufs_create, | |
1404 | .lookup = aufs_lookup, | |
1405 | .link = aufs_link, | |
1406 | .unlink = aufs_unlink, | |
1407 | .symlink = aufs_symlink, | |
1408 | .mkdir = aufs_mkdir, | |
1409 | .rmdir = aufs_rmdir, | |
1410 | .mknod = aufs_mknod, | |
1411 | .rename = aufs_rename, | |
1412 | ||
1413 | .permission = aufs_permission, | |
1414 | #ifdef CONFIG_FS_POSIX_ACL | |
1415 | .get_acl = aufs_get_acl, | |
1416 | .set_acl = aufs_set_acl, | |
1417 | #endif | |
1418 | ||
1419 | .setattr = aufs_setattr, | |
1420 | .getattr = aufs_getattr, | |
1421 | ||
1422 | #ifdef CONFIG_AUFS_XATTR | |
5b88fdd9 | 1423 | .listxattr = aufs_listxattr, |
5b88fdd9 SF |
1424 | #endif |
1425 | ||
1426 | .update_time = aufs_update_time, | |
1427 | .atomic_open = aufs_atomic_open, | |
1428 | .tmpfile = aufs_tmpfile | |
1429 | }, | |
1430 | [AuIop_OTHER] = { | |
1431 | .permission = aufs_permission, | |
1432 | #ifdef CONFIG_FS_POSIX_ACL | |
1433 | .get_acl = aufs_get_acl, | |
1434 | .set_acl = aufs_set_acl, | |
1435 | #endif | |
1436 | ||
1437 | .setattr = aufs_setattr, | |
1438 | .getattr = aufs_getattr, | |
1439 | ||
1440 | #ifdef CONFIG_AUFS_XATTR | |
5b88fdd9 | 1441 | .listxattr = aufs_listxattr, |
5b88fdd9 SF |
1442 | #endif |
1443 | ||
1444 | .update_time = aufs_update_time | |
1445 | } | |
1446 | }; |