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1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
e4a3f096 | 3 | * Copyright (C) 2005-2020 Junjiro R. Okajima |
a3a49a17 SF |
4 | * |
5 | * This program, aufs is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
18 | ||
19 | /* | |
20 | * lookup and dentry operations | |
21 | */ | |
22 | ||
23 | #include <linux/iversion.h> | |
24 | #include <linux/namei.h> | |
25 | #include "aufs.h" | |
26 | ||
27 | /* | |
28 | * returns positive/negative dentry, NULL or an error. | |
29 | * NULL means whiteout-ed or not-found. | |
30 | */ | |
31 | static struct dentry* | |
32 | au_do_lookup(struct dentry *h_parent, struct dentry *dentry, | |
33 | aufs_bindex_t bindex, struct au_do_lookup_args *args) | |
34 | { | |
35 | struct dentry *h_dentry; | |
36 | struct inode *h_inode; | |
37 | struct au_branch *br; | |
38 | int wh_found, opq; | |
39 | unsigned char wh_able; | |
40 | const unsigned char allow_neg = !!au_ftest_lkup(args->flags, ALLOW_NEG); | |
41 | const unsigned char ignore_perm = !!au_ftest_lkup(args->flags, | |
42 | IGNORE_PERM); | |
43 | ||
44 | wh_found = 0; | |
45 | br = au_sbr(dentry->d_sb, bindex); | |
46 | wh_able = !!au_br_whable(br->br_perm); | |
47 | if (wh_able) | |
48 | wh_found = au_wh_test(h_parent, &args->whname, ignore_perm); | |
49 | h_dentry = ERR_PTR(wh_found); | |
50 | if (!wh_found) | |
51 | goto real_lookup; | |
52 | if (unlikely(wh_found < 0)) | |
53 | goto out; | |
54 | ||
55 | /* We found a whiteout */ | |
56 | /* au_set_dbbot(dentry, bindex); */ | |
57 | au_set_dbwh(dentry, bindex); | |
58 | if (!allow_neg) | |
59 | return NULL; /* success */ | |
60 | ||
61 | real_lookup: | |
62 | if (!ignore_perm) | |
63 | h_dentry = vfsub_lkup_one(args->name, h_parent); | |
64 | else | |
65 | h_dentry = au_sio_lkup_one(args->name, h_parent); | |
66 | if (IS_ERR(h_dentry)) { | |
67 | if (PTR_ERR(h_dentry) == -ENAMETOOLONG | |
68 | && !allow_neg) | |
69 | h_dentry = NULL; | |
70 | goto out; | |
71 | } | |
72 | ||
73 | h_inode = d_inode(h_dentry); | |
74 | if (d_is_negative(h_dentry)) { | |
75 | if (!allow_neg) | |
76 | goto out_neg; | |
77 | } else if (wh_found | |
78 | || (args->type && args->type != (h_inode->i_mode & S_IFMT))) | |
79 | goto out_neg; | |
80 | else if (au_ftest_lkup(args->flags, DIRREN) | |
81 | /* && h_inode */ | |
82 | && !au_dr_lkup_h_ino(args, bindex, h_inode->i_ino)) { | |
83 | AuDbg("b%d %pd ignored hi%llu\n", bindex, h_dentry, | |
84 | (unsigned long long)h_inode->i_ino); | |
85 | goto out_neg; | |
86 | } | |
87 | ||
88 | if (au_dbbot(dentry) <= bindex) | |
89 | au_set_dbbot(dentry, bindex); | |
90 | if (au_dbtop(dentry) < 0 || bindex < au_dbtop(dentry)) | |
91 | au_set_dbtop(dentry, bindex); | |
92 | au_set_h_dptr(dentry, bindex, h_dentry); | |
93 | ||
94 | if (!d_is_dir(h_dentry) | |
95 | || !wh_able | |
96 | || (d_really_is_positive(dentry) && !d_is_dir(dentry))) | |
97 | goto out; /* success */ | |
98 | ||
99 | inode_lock_shared_nested(h_inode, AuLsc_I_CHILD); | |
100 | opq = au_diropq_test(h_dentry); | |
101 | inode_unlock_shared(h_inode); | |
102 | if (opq > 0) | |
103 | au_set_dbdiropq(dentry, bindex); | |
104 | else if (unlikely(opq < 0)) { | |
105 | au_set_h_dptr(dentry, bindex, NULL); | |
106 | h_dentry = ERR_PTR(opq); | |
107 | } | |
108 | goto out; | |
109 | ||
110 | out_neg: | |
111 | dput(h_dentry); | |
112 | h_dentry = NULL; | |
113 | out: | |
114 | return h_dentry; | |
115 | } | |
116 | ||
117 | static int au_test_shwh(struct super_block *sb, const struct qstr *name) | |
118 | { | |
119 | if (unlikely(!au_opt_test(au_mntflags(sb), SHWH) | |
120 | && !strncmp(name->name, AUFS_WH_PFX, AUFS_WH_PFX_LEN))) | |
121 | return -EPERM; | |
122 | return 0; | |
123 | } | |
124 | ||
125 | /* | |
126 | * returns the number of lower positive dentries, | |
127 | * otherwise an error. | |
128 | * can be called at unlinking with @type is zero. | |
129 | */ | |
130 | int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t btop, | |
131 | unsigned int flags) | |
132 | { | |
133 | int npositive, err; | |
134 | aufs_bindex_t bindex, btail, bdiropq; | |
135 | unsigned char isdir, dirperm1, dirren; | |
136 | struct au_do_lookup_args args = { | |
137 | .flags = flags, | |
138 | .name = &dentry->d_name | |
139 | }; | |
140 | struct dentry *parent; | |
141 | struct super_block *sb; | |
142 | ||
143 | sb = dentry->d_sb; | |
144 | err = au_test_shwh(sb, args.name); | |
145 | if (unlikely(err)) | |
146 | goto out; | |
147 | ||
148 | err = au_wh_name_alloc(&args.whname, args.name); | |
149 | if (unlikely(err)) | |
150 | goto out; | |
151 | ||
152 | isdir = !!d_is_dir(dentry); | |
153 | dirperm1 = !!au_opt_test(au_mntflags(sb), DIRPERM1); | |
154 | dirren = !!au_opt_test(au_mntflags(sb), DIRREN); | |
155 | if (dirren) | |
156 | au_fset_lkup(args.flags, DIRREN); | |
157 | ||
158 | npositive = 0; | |
159 | parent = dget_parent(dentry); | |
160 | btail = au_dbtaildir(parent); | |
161 | for (bindex = btop; bindex <= btail; bindex++) { | |
162 | struct dentry *h_parent, *h_dentry; | |
163 | struct inode *h_inode, *h_dir; | |
164 | struct au_branch *br; | |
165 | ||
166 | h_dentry = au_h_dptr(dentry, bindex); | |
167 | if (h_dentry) { | |
168 | if (d_is_positive(h_dentry)) | |
169 | npositive++; | |
170 | break; | |
171 | } | |
172 | h_parent = au_h_dptr(parent, bindex); | |
173 | if (!h_parent || !d_is_dir(h_parent)) | |
174 | continue; | |
175 | ||
176 | if (dirren) { | |
177 | /* if the inum matches, then use the prepared name */ | |
178 | err = au_dr_lkup_name(&args, bindex); | |
179 | if (unlikely(err)) | |
180 | goto out_parent; | |
181 | } | |
182 | ||
183 | h_dir = d_inode(h_parent); | |
184 | inode_lock_shared_nested(h_dir, AuLsc_I_PARENT); | |
185 | h_dentry = au_do_lookup(h_parent, dentry, bindex, &args); | |
186 | inode_unlock_shared(h_dir); | |
187 | err = PTR_ERR(h_dentry); | |
188 | if (IS_ERR(h_dentry)) | |
189 | goto out_parent; | |
190 | if (h_dentry) | |
191 | au_fclr_lkup(args.flags, ALLOW_NEG); | |
192 | if (dirperm1) | |
193 | au_fset_lkup(args.flags, IGNORE_PERM); | |
194 | ||
195 | if (au_dbwh(dentry) == bindex) | |
196 | break; | |
197 | if (!h_dentry) | |
198 | continue; | |
199 | if (d_is_negative(h_dentry)) | |
200 | continue; | |
201 | h_inode = d_inode(h_dentry); | |
202 | npositive++; | |
203 | if (!args.type) | |
204 | args.type = h_inode->i_mode & S_IFMT; | |
205 | if (args.type != S_IFDIR) | |
206 | break; | |
207 | else if (isdir) { | |
208 | /* the type of lower may be different */ | |
209 | bdiropq = au_dbdiropq(dentry); | |
210 | if (bdiropq >= 0 && bdiropq <= bindex) | |
211 | break; | |
212 | } | |
213 | br = au_sbr(sb, bindex); | |
214 | if (dirren | |
215 | && au_dr_hino_test_add(&br->br_dirren, h_inode->i_ino, | |
216 | /*add_ent*/NULL)) { | |
217 | /* prepare next name to lookup */ | |
218 | err = au_dr_lkup(&args, dentry, bindex); | |
219 | if (unlikely(err)) | |
220 | goto out_parent; | |
221 | } | |
222 | } | |
223 | ||
224 | if (npositive) { | |
225 | AuLabel(positive); | |
226 | au_update_dbtop(dentry); | |
227 | } | |
228 | err = npositive; | |
229 | if (unlikely(!au_opt_test(au_mntflags(sb), UDBA_NONE) | |
230 | && au_dbtop(dentry) < 0)) { | |
231 | err = -EIO; | |
232 | AuIOErr("both of real entry and whiteout found, %pd, err %d\n", | |
233 | dentry, err); | |
234 | } | |
235 | ||
236 | out_parent: | |
237 | dput(parent); | |
238 | au_kfree_try_rcu(args.whname.name); | |
239 | if (dirren) | |
240 | au_dr_lkup_fin(&args); | |
241 | out: | |
242 | return err; | |
243 | } | |
244 | ||
245 | struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent) | |
246 | { | |
247 | struct dentry *dentry; | |
248 | int wkq_err; | |
249 | ||
250 | if (!au_test_h_perm_sio(d_inode(parent), MAY_EXEC)) | |
251 | dentry = vfsub_lkup_one(name, parent); | |
252 | else { | |
253 | struct vfsub_lkup_one_args args = { | |
254 | .errp = &dentry, | |
255 | .name = name, | |
256 | .parent = parent | |
257 | }; | |
258 | ||
259 | wkq_err = au_wkq_wait(vfsub_call_lkup_one, &args); | |
260 | if (unlikely(wkq_err)) | |
261 | dentry = ERR_PTR(wkq_err); | |
262 | } | |
263 | ||
264 | return dentry; | |
265 | } | |
266 | ||
267 | /* | |
268 | * lookup @dentry on @bindex which should be negative. | |
269 | */ | |
270 | int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex, int wh) | |
271 | { | |
272 | int err; | |
273 | struct dentry *parent, *h_parent, *h_dentry; | |
274 | struct au_branch *br; | |
275 | ||
276 | parent = dget_parent(dentry); | |
277 | h_parent = au_h_dptr(parent, bindex); | |
278 | br = au_sbr(dentry->d_sb, bindex); | |
279 | if (wh) | |
280 | h_dentry = au_whtmp_lkup(h_parent, br, &dentry->d_name); | |
281 | else | |
282 | h_dentry = au_sio_lkup_one(&dentry->d_name, h_parent); | |
283 | err = PTR_ERR(h_dentry); | |
284 | if (IS_ERR(h_dentry)) | |
285 | goto out; | |
286 | if (unlikely(d_is_positive(h_dentry))) { | |
287 | err = -EIO; | |
288 | AuIOErr("%pd should be negative on b%d.\n", h_dentry, bindex); | |
289 | dput(h_dentry); | |
290 | goto out; | |
291 | } | |
292 | ||
293 | err = 0; | |
294 | if (bindex < au_dbtop(dentry)) | |
295 | au_set_dbtop(dentry, bindex); | |
296 | if (au_dbbot(dentry) < bindex) | |
297 | au_set_dbbot(dentry, bindex); | |
298 | au_set_h_dptr(dentry, bindex, h_dentry); | |
299 | ||
300 | out: | |
301 | dput(parent); | |
302 | return err; | |
303 | } | |
304 | ||
305 | /* ---------------------------------------------------------------------- */ | |
306 | ||
307 | /* subset of struct inode */ | |
308 | struct au_iattr { | |
309 | unsigned long i_ino; | |
310 | /* unsigned int i_nlink; */ | |
311 | kuid_t i_uid; | |
312 | kgid_t i_gid; | |
313 | u64 i_version; | |
314 | /* | |
315 | loff_t i_size; | |
316 | blkcnt_t i_blocks; | |
317 | */ | |
318 | umode_t i_mode; | |
319 | }; | |
320 | ||
321 | static void au_iattr_save(struct au_iattr *ia, struct inode *h_inode) | |
322 | { | |
323 | ia->i_ino = h_inode->i_ino; | |
324 | /* ia->i_nlink = h_inode->i_nlink; */ | |
325 | ia->i_uid = h_inode->i_uid; | |
326 | ia->i_gid = h_inode->i_gid; | |
327 | ia->i_version = inode_query_iversion(h_inode); | |
328 | /* | |
329 | ia->i_size = h_inode->i_size; | |
330 | ia->i_blocks = h_inode->i_blocks; | |
331 | */ | |
332 | ia->i_mode = (h_inode->i_mode & S_IFMT); | |
333 | } | |
334 | ||
335 | static int au_iattr_test(struct au_iattr *ia, struct inode *h_inode) | |
336 | { | |
337 | return ia->i_ino != h_inode->i_ino | |
338 | /* || ia->i_nlink != h_inode->i_nlink */ | |
339 | || !uid_eq(ia->i_uid, h_inode->i_uid) | |
340 | || !gid_eq(ia->i_gid, h_inode->i_gid) | |
341 | || !inode_eq_iversion(h_inode, ia->i_version) | |
342 | /* | |
343 | || ia->i_size != h_inode->i_size | |
344 | || ia->i_blocks != h_inode->i_blocks | |
345 | */ | |
346 | || ia->i_mode != (h_inode->i_mode & S_IFMT); | |
347 | } | |
348 | ||
349 | static int au_h_verify_dentry(struct dentry *h_dentry, struct dentry *h_parent, | |
350 | struct au_branch *br) | |
351 | { | |
352 | int err; | |
353 | struct au_iattr ia; | |
354 | struct inode *h_inode; | |
355 | struct dentry *h_d; | |
356 | struct super_block *h_sb; | |
357 | ||
358 | err = 0; | |
359 | memset(&ia, -1, sizeof(ia)); | |
360 | h_sb = h_dentry->d_sb; | |
361 | h_inode = NULL; | |
362 | if (d_is_positive(h_dentry)) { | |
363 | h_inode = d_inode(h_dentry); | |
364 | au_iattr_save(&ia, h_inode); | |
365 | } else if (au_test_nfs(h_sb) || au_test_fuse(h_sb)) | |
366 | /* nfs d_revalidate may return 0 for negative dentry */ | |
367 | /* fuse d_revalidate always return 0 for negative dentry */ | |
368 | goto out; | |
369 | ||
370 | /* main purpose is namei.c:cached_lookup() and d_revalidate */ | |
371 | h_d = vfsub_lkup_one(&h_dentry->d_name, h_parent); | |
372 | err = PTR_ERR(h_d); | |
373 | if (IS_ERR(h_d)) | |
374 | goto out; | |
375 | ||
376 | err = 0; | |
377 | if (unlikely(h_d != h_dentry | |
378 | || d_inode(h_d) != h_inode | |
379 | || (h_inode && au_iattr_test(&ia, h_inode)))) | |
380 | err = au_busy_or_stale(); | |
381 | dput(h_d); | |
382 | ||
383 | out: | |
384 | AuTraceErr(err); | |
385 | return err; | |
386 | } | |
387 | ||
388 | int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir, | |
389 | struct dentry *h_parent, struct au_branch *br) | |
390 | { | |
391 | int err; | |
392 | ||
393 | err = 0; | |
394 | if (udba == AuOpt_UDBA_REVAL | |
395 | && !au_test_fs_remote(h_dentry->d_sb)) { | |
396 | IMustLock(h_dir); | |
397 | err = (d_inode(h_dentry->d_parent) != h_dir); | |
398 | } else if (udba != AuOpt_UDBA_NONE) | |
399 | err = au_h_verify_dentry(h_dentry, h_parent, br); | |
400 | ||
401 | return err; | |
402 | } | |
403 | ||
404 | /* ---------------------------------------------------------------------- */ | |
405 | ||
406 | static int au_do_refresh_hdentry(struct dentry *dentry, struct dentry *parent) | |
407 | { | |
408 | int err; | |
409 | aufs_bindex_t new_bindex, bindex, bbot, bwh, bdiropq; | |
410 | struct au_hdentry tmp, *p, *q; | |
411 | struct au_dinfo *dinfo; | |
412 | struct super_block *sb; | |
413 | ||
414 | DiMustWriteLock(dentry); | |
415 | ||
416 | sb = dentry->d_sb; | |
417 | dinfo = au_di(dentry); | |
418 | bbot = dinfo->di_bbot; | |
419 | bwh = dinfo->di_bwh; | |
420 | bdiropq = dinfo->di_bdiropq; | |
421 | bindex = dinfo->di_btop; | |
422 | p = au_hdentry(dinfo, bindex); | |
423 | for (; bindex <= bbot; bindex++, p++) { | |
424 | if (!p->hd_dentry) | |
425 | continue; | |
426 | ||
427 | new_bindex = au_br_index(sb, p->hd_id); | |
428 | if (new_bindex == bindex) | |
429 | continue; | |
430 | ||
431 | if (dinfo->di_bwh == bindex) | |
432 | bwh = new_bindex; | |
433 | if (dinfo->di_bdiropq == bindex) | |
434 | bdiropq = new_bindex; | |
435 | if (new_bindex < 0) { | |
436 | au_hdput(p); | |
437 | p->hd_dentry = NULL; | |
438 | continue; | |
439 | } | |
440 | ||
441 | /* swap two lower dentries, and loop again */ | |
442 | q = au_hdentry(dinfo, new_bindex); | |
443 | tmp = *q; | |
444 | *q = *p; | |
445 | *p = tmp; | |
446 | if (tmp.hd_dentry) { | |
447 | bindex--; | |
448 | p--; | |
449 | } | |
450 | } | |
451 | ||
452 | dinfo->di_bwh = -1; | |
453 | if (bwh >= 0 && bwh <= au_sbbot(sb) && au_sbr_whable(sb, bwh)) | |
454 | dinfo->di_bwh = bwh; | |
455 | ||
456 | dinfo->di_bdiropq = -1; | |
457 | if (bdiropq >= 0 | |
458 | && bdiropq <= au_sbbot(sb) | |
459 | && au_sbr_whable(sb, bdiropq)) | |
460 | dinfo->di_bdiropq = bdiropq; | |
461 | ||
462 | err = -EIO; | |
463 | dinfo->di_btop = -1; | |
464 | dinfo->di_bbot = -1; | |
465 | bbot = au_dbbot(parent); | |
466 | bindex = 0; | |
467 | p = au_hdentry(dinfo, bindex); | |
468 | for (; bindex <= bbot; bindex++, p++) | |
469 | if (p->hd_dentry) { | |
470 | dinfo->di_btop = bindex; | |
471 | break; | |
472 | } | |
473 | ||
474 | if (dinfo->di_btop >= 0) { | |
475 | bindex = bbot; | |
476 | p = au_hdentry(dinfo, bindex); | |
477 | for (; bindex >= 0; bindex--, p--) | |
478 | if (p->hd_dentry) { | |
479 | dinfo->di_bbot = bindex; | |
480 | err = 0; | |
481 | break; | |
482 | } | |
483 | } | |
484 | ||
485 | return err; | |
486 | } | |
487 | ||
488 | static void au_do_hide(struct dentry *dentry) | |
489 | { | |
490 | struct inode *inode; | |
491 | ||
492 | if (d_really_is_positive(dentry)) { | |
493 | inode = d_inode(dentry); | |
494 | if (!d_is_dir(dentry)) { | |
495 | if (inode->i_nlink && !d_unhashed(dentry)) | |
496 | drop_nlink(inode); | |
497 | } else { | |
498 | clear_nlink(inode); | |
499 | /* stop next lookup */ | |
500 | inode->i_flags |= S_DEAD; | |
501 | } | |
502 | smp_mb(); /* necessary? */ | |
503 | } | |
504 | d_drop(dentry); | |
505 | } | |
506 | ||
507 | static int au_hide_children(struct dentry *parent) | |
508 | { | |
509 | int err, i, j, ndentry; | |
510 | struct au_dcsub_pages dpages; | |
511 | struct au_dpage *dpage; | |
512 | struct dentry *dentry; | |
513 | ||
514 | err = au_dpages_init(&dpages, GFP_NOFS); | |
515 | if (unlikely(err)) | |
516 | goto out; | |
517 | err = au_dcsub_pages(&dpages, parent, NULL, NULL); | |
518 | if (unlikely(err)) | |
519 | goto out_dpages; | |
520 | ||
521 | /* in reverse order */ | |
522 | for (i = dpages.ndpage - 1; i >= 0; i--) { | |
523 | dpage = dpages.dpages + i; | |
524 | ndentry = dpage->ndentry; | |
525 | for (j = ndentry - 1; j >= 0; j--) { | |
526 | dentry = dpage->dentries[j]; | |
527 | if (dentry != parent) | |
528 | au_do_hide(dentry); | |
529 | } | |
530 | } | |
531 | ||
532 | out_dpages: | |
533 | au_dpages_free(&dpages); | |
534 | out: | |
535 | return err; | |
536 | } | |
537 | ||
538 | static void au_hide(struct dentry *dentry) | |
539 | { | |
540 | int err; | |
541 | ||
542 | AuDbgDentry(dentry); | |
543 | if (d_is_dir(dentry)) { | |
544 | /* shrink_dcache_parent(dentry); */ | |
545 | err = au_hide_children(dentry); | |
546 | if (unlikely(err)) | |
547 | AuIOErr("%pd, failed hiding children, ignored %d\n", | |
548 | dentry, err); | |
549 | } | |
550 | au_do_hide(dentry); | |
551 | } | |
552 | ||
553 | /* | |
554 | * By adding a dirty branch, a cached dentry may be affected in various ways. | |
555 | * | |
556 | * a dirty branch is added | |
557 | * - on the top of layers | |
558 | * - in the middle of layers | |
559 | * - to the bottom of layers | |
560 | * | |
561 | * on the added branch there exists | |
562 | * - a whiteout | |
563 | * - a diropq | |
564 | * - a same named entry | |
565 | * + exist | |
566 | * * negative --> positive | |
567 | * * positive --> positive | |
568 | * - type is unchanged | |
569 | * - type is changed | |
570 | * + doesn't exist | |
571 | * * negative --> negative | |
572 | * * positive --> negative (rejected by au_br_del() for non-dir case) | |
573 | * - none | |
574 | */ | |
575 | static int au_refresh_by_dinfo(struct dentry *dentry, struct au_dinfo *dinfo, | |
576 | struct au_dinfo *tmp) | |
577 | { | |
578 | int err; | |
579 | aufs_bindex_t bindex, bbot; | |
580 | struct { | |
581 | struct dentry *dentry; | |
582 | struct inode *inode; | |
583 | mode_t mode; | |
584 | } orig_h, tmp_h = { | |
585 | .dentry = NULL | |
586 | }; | |
587 | struct au_hdentry *hd; | |
588 | struct inode *inode, *h_inode; | |
589 | struct dentry *h_dentry; | |
590 | ||
591 | err = 0; | |
592 | AuDebugOn(dinfo->di_btop < 0); | |
593 | orig_h.mode = 0; | |
594 | orig_h.dentry = au_hdentry(dinfo, dinfo->di_btop)->hd_dentry; | |
595 | orig_h.inode = NULL; | |
596 | if (d_is_positive(orig_h.dentry)) { | |
597 | orig_h.inode = d_inode(orig_h.dentry); | |
598 | orig_h.mode = orig_h.inode->i_mode & S_IFMT; | |
599 | } | |
600 | if (tmp->di_btop >= 0) { | |
601 | tmp_h.dentry = au_hdentry(tmp, tmp->di_btop)->hd_dentry; | |
602 | if (d_is_positive(tmp_h.dentry)) { | |
603 | tmp_h.inode = d_inode(tmp_h.dentry); | |
604 | tmp_h.mode = tmp_h.inode->i_mode & S_IFMT; | |
605 | } | |
606 | } | |
607 | ||
608 | inode = NULL; | |
609 | if (d_really_is_positive(dentry)) | |
610 | inode = d_inode(dentry); | |
611 | if (!orig_h.inode) { | |
612 | AuDbg("negative originally\n"); | |
613 | if (inode) { | |
614 | au_hide(dentry); | |
615 | goto out; | |
616 | } | |
617 | AuDebugOn(inode); | |
618 | AuDebugOn(dinfo->di_btop != dinfo->di_bbot); | |
619 | AuDebugOn(dinfo->di_bdiropq != -1); | |
620 | ||
621 | if (!tmp_h.inode) { | |
622 | AuDbg("negative --> negative\n"); | |
623 | /* should have only one negative lower */ | |
624 | if (tmp->di_btop >= 0 | |
625 | && tmp->di_btop < dinfo->di_btop) { | |
626 | AuDebugOn(tmp->di_btop != tmp->di_bbot); | |
627 | AuDebugOn(dinfo->di_btop != dinfo->di_bbot); | |
628 | au_set_h_dptr(dentry, dinfo->di_btop, NULL); | |
629 | au_di_cp(dinfo, tmp); | |
630 | hd = au_hdentry(tmp, tmp->di_btop); | |
631 | au_set_h_dptr(dentry, tmp->di_btop, | |
632 | dget(hd->hd_dentry)); | |
633 | } | |
634 | au_dbg_verify_dinode(dentry); | |
635 | } else { | |
636 | AuDbg("negative --> positive\n"); | |
637 | /* | |
638 | * similar to the behaviour of creating with bypassing | |
639 | * aufs. | |
640 | * unhash it in order to force an error in the | |
641 | * succeeding create operation. | |
642 | * we should not set S_DEAD here. | |
643 | */ | |
644 | d_drop(dentry); | |
645 | /* au_di_swap(tmp, dinfo); */ | |
646 | au_dbg_verify_dinode(dentry); | |
647 | } | |
648 | } else { | |
649 | AuDbg("positive originally\n"); | |
650 | /* inode may be NULL */ | |
651 | AuDebugOn(inode && (inode->i_mode & S_IFMT) != orig_h.mode); | |
652 | if (!tmp_h.inode) { | |
653 | AuDbg("positive --> negative\n"); | |
654 | /* or bypassing aufs */ | |
655 | au_hide(dentry); | |
656 | if (tmp->di_bwh >= 0 && tmp->di_bwh <= dinfo->di_btop) | |
657 | dinfo->di_bwh = tmp->di_bwh; | |
658 | if (inode) | |
659 | err = au_refresh_hinode_self(inode); | |
660 | au_dbg_verify_dinode(dentry); | |
661 | } else if (orig_h.mode == tmp_h.mode) { | |
662 | AuDbg("positive --> positive, same type\n"); | |
663 | if (!S_ISDIR(orig_h.mode) | |
664 | && dinfo->di_btop > tmp->di_btop) { | |
665 | /* | |
666 | * similar to the behaviour of removing and | |
667 | * creating. | |
668 | */ | |
669 | au_hide(dentry); | |
670 | if (inode) | |
671 | err = au_refresh_hinode_self(inode); | |
672 | au_dbg_verify_dinode(dentry); | |
673 | } else { | |
674 | /* fill empty slots */ | |
675 | if (dinfo->di_btop > tmp->di_btop) | |
676 | dinfo->di_btop = tmp->di_btop; | |
677 | if (dinfo->di_bbot < tmp->di_bbot) | |
678 | dinfo->di_bbot = tmp->di_bbot; | |
679 | dinfo->di_bwh = tmp->di_bwh; | |
680 | dinfo->di_bdiropq = tmp->di_bdiropq; | |
681 | bbot = dinfo->di_bbot; | |
682 | bindex = tmp->di_btop; | |
683 | hd = au_hdentry(tmp, bindex); | |
684 | for (; bindex <= bbot; bindex++, hd++) { | |
685 | if (au_h_dptr(dentry, bindex)) | |
686 | continue; | |
687 | h_dentry = hd->hd_dentry; | |
688 | if (!h_dentry) | |
689 | continue; | |
690 | AuDebugOn(d_is_negative(h_dentry)); | |
691 | h_inode = d_inode(h_dentry); | |
692 | AuDebugOn(orig_h.mode | |
693 | != (h_inode->i_mode | |
694 | & S_IFMT)); | |
695 | au_set_h_dptr(dentry, bindex, | |
696 | dget(h_dentry)); | |
697 | } | |
698 | if (inode) | |
699 | err = au_refresh_hinode(inode, dentry); | |
700 | au_dbg_verify_dinode(dentry); | |
701 | } | |
702 | } else { | |
703 | AuDbg("positive --> positive, different type\n"); | |
704 | /* similar to the behaviour of removing and creating */ | |
705 | au_hide(dentry); | |
706 | if (inode) | |
707 | err = au_refresh_hinode_self(inode); | |
708 | au_dbg_verify_dinode(dentry); | |
709 | } | |
710 | } | |
711 | ||
712 | out: | |
713 | return err; | |
714 | } | |
715 | ||
716 | void au_refresh_dop(struct dentry *dentry, int force_reval) | |
717 | { | |
718 | const struct dentry_operations *dop | |
719 | = force_reval ? &aufs_dop : dentry->d_sb->s_d_op; | |
720 | static const unsigned int mask | |
721 | = DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE; | |
722 | ||
723 | BUILD_BUG_ON(sizeof(mask) != sizeof(dentry->d_flags)); | |
724 | ||
725 | if (dentry->d_op == dop) | |
726 | return; | |
727 | ||
728 | AuDbg("%pd\n", dentry); | |
729 | spin_lock(&dentry->d_lock); | |
730 | if (dop == &aufs_dop) | |
731 | dentry->d_flags |= mask; | |
732 | else | |
733 | dentry->d_flags &= ~mask; | |
734 | dentry->d_op = dop; | |
735 | spin_unlock(&dentry->d_lock); | |
736 | } | |
737 | ||
738 | int au_refresh_dentry(struct dentry *dentry, struct dentry *parent) | |
739 | { | |
740 | int err, ebrange, nbr; | |
741 | unsigned int sigen; | |
742 | struct au_dinfo *dinfo, *tmp; | |
743 | struct super_block *sb; | |
744 | struct inode *inode; | |
745 | ||
746 | DiMustWriteLock(dentry); | |
747 | AuDebugOn(IS_ROOT(dentry)); | |
748 | AuDebugOn(d_really_is_negative(parent)); | |
749 | ||
750 | sb = dentry->d_sb; | |
751 | sigen = au_sigen(sb); | |
752 | err = au_digen_test(parent, sigen); | |
753 | if (unlikely(err)) | |
754 | goto out; | |
755 | ||
756 | nbr = au_sbbot(sb) + 1; | |
757 | dinfo = au_di(dentry); | |
758 | err = au_di_realloc(dinfo, nbr, /*may_shrink*/0); | |
759 | if (unlikely(err)) | |
760 | goto out; | |
761 | ebrange = au_dbrange_test(dentry); | |
762 | if (!ebrange) | |
763 | ebrange = au_do_refresh_hdentry(dentry, parent); | |
764 | ||
765 | if (d_unhashed(dentry) || ebrange /* || dinfo->di_tmpfile */) { | |
766 | AuDebugOn(au_dbtop(dentry) < 0 && au_dbbot(dentry) >= 0); | |
767 | if (d_really_is_positive(dentry)) { | |
768 | inode = d_inode(dentry); | |
769 | err = au_refresh_hinode_self(inode); | |
770 | } | |
771 | au_dbg_verify_dinode(dentry); | |
772 | if (!err) | |
773 | goto out_dgen; /* success */ | |
774 | goto out; | |
775 | } | |
776 | ||
777 | /* temporary dinfo */ | |
778 | AuDbgDentry(dentry); | |
779 | err = -ENOMEM; | |
780 | tmp = au_di_alloc(sb, AuLsc_DI_TMP); | |
781 | if (unlikely(!tmp)) | |
782 | goto out; | |
783 | au_di_swap(tmp, dinfo); | |
784 | /* returns the number of positive dentries */ | |
785 | /* | |
786 | * if current working dir is removed, it returns an error. | |
787 | * but the dentry is legal. | |
788 | */ | |
789 | err = au_lkup_dentry(dentry, /*btop*/0, AuLkup_ALLOW_NEG); | |
790 | AuDbgDentry(dentry); | |
791 | au_di_swap(tmp, dinfo); | |
792 | if (err == -ENOENT) | |
793 | err = 0; | |
794 | if (err >= 0) { | |
795 | /* compare/refresh by dinfo */ | |
796 | AuDbgDentry(dentry); | |
797 | err = au_refresh_by_dinfo(dentry, dinfo, tmp); | |
798 | au_dbg_verify_dinode(dentry); | |
799 | AuTraceErr(err); | |
800 | } | |
801 | au_di_realloc(dinfo, nbr, /*may_shrink*/1); /* harmless if err */ | |
802 | au_rw_write_unlock(&tmp->di_rwsem); | |
803 | au_di_free(tmp); | |
804 | if (unlikely(err)) | |
805 | goto out; | |
806 | ||
807 | out_dgen: | |
808 | au_update_digen(dentry); | |
809 | out: | |
810 | if (unlikely(err && !(dentry->d_flags & DCACHE_NFSFS_RENAMED))) { | |
811 | AuIOErr("failed refreshing %pd, %d\n", dentry, err); | |
812 | AuDbgDentry(dentry); | |
813 | } | |
814 | AuTraceErr(err); | |
815 | return err; | |
816 | } | |
817 | ||
818 | static int au_do_h_d_reval(struct dentry *h_dentry, unsigned int flags, | |
819 | struct dentry *dentry, aufs_bindex_t bindex) | |
820 | { | |
821 | int err, valid; | |
822 | ||
823 | err = 0; | |
824 | if (!(h_dentry->d_flags & DCACHE_OP_REVALIDATE)) | |
825 | goto out; | |
826 | ||
827 | AuDbg("b%d\n", bindex); | |
828 | /* | |
829 | * gave up supporting LOOKUP_CREATE/OPEN for lower fs, | |
830 | * due to whiteout and branch permission. | |
831 | */ | |
832 | flags &= ~(/*LOOKUP_PARENT |*/ LOOKUP_OPEN | LOOKUP_CREATE | |
833 | | LOOKUP_FOLLOW | LOOKUP_EXCL); | |
834 | /* it may return tri-state */ | |
835 | valid = h_dentry->d_op->d_revalidate(h_dentry, flags); | |
836 | ||
837 | if (unlikely(valid < 0)) | |
838 | err = valid; | |
839 | else if (!valid) | |
840 | err = -EINVAL; | |
841 | ||
842 | out: | |
843 | AuTraceErr(err); | |
844 | return err; | |
845 | } | |
846 | ||
847 | /* todo: remove this */ | |
848 | static int h_d_revalidate(struct dentry *dentry, struct inode *inode, | |
849 | unsigned int flags, int do_udba, int dirren) | |
850 | { | |
851 | int err; | |
852 | umode_t mode, h_mode; | |
853 | aufs_bindex_t bindex, btail, btop, ibs, ibe; | |
854 | unsigned char plus, unhashed, is_root, h_plus, h_nfs, tmpfile; | |
855 | struct inode *h_inode, *h_cached_inode; | |
856 | struct dentry *h_dentry; | |
857 | struct qstr *name, *h_name; | |
858 | ||
859 | err = 0; | |
860 | plus = 0; | |
861 | mode = 0; | |
862 | ibs = -1; | |
863 | ibe = -1; | |
864 | unhashed = !!d_unhashed(dentry); | |
865 | is_root = !!IS_ROOT(dentry); | |
866 | name = &dentry->d_name; | |
867 | tmpfile = au_di(dentry)->di_tmpfile; | |
868 | ||
869 | /* | |
870 | * Theoretically, REVAL test should be unnecessary in case of | |
871 | * {FS,I}NOTIFY. | |
872 | * But {fs,i}notify doesn't fire some necessary events, | |
873 | * IN_ATTRIB for atime/nlink/pageio | |
874 | * Let's do REVAL test too. | |
875 | */ | |
876 | if (do_udba && inode) { | |
877 | mode = (inode->i_mode & S_IFMT); | |
878 | plus = (inode->i_nlink > 0); | |
879 | ibs = au_ibtop(inode); | |
880 | ibe = au_ibbot(inode); | |
881 | } | |
882 | ||
883 | btop = au_dbtop(dentry); | |
884 | btail = btop; | |
885 | if (inode && S_ISDIR(inode->i_mode)) | |
886 | btail = au_dbtaildir(dentry); | |
887 | for (bindex = btop; bindex <= btail; bindex++) { | |
888 | h_dentry = au_h_dptr(dentry, bindex); | |
889 | if (!h_dentry) | |
890 | continue; | |
891 | ||
892 | AuDbg("b%d, %pd\n", bindex, h_dentry); | |
893 | h_nfs = !!au_test_nfs(h_dentry->d_sb); | |
894 | spin_lock(&h_dentry->d_lock); | |
895 | h_name = &h_dentry->d_name; | |
896 | if (unlikely(do_udba | |
897 | && !is_root | |
898 | && ((!h_nfs | |
899 | && (unhashed != !!d_unhashed(h_dentry) | |
900 | || (!tmpfile && !dirren | |
901 | && !au_qstreq(name, h_name)) | |
902 | )) | |
903 | || (h_nfs | |
904 | && !(flags & LOOKUP_OPEN) | |
905 | && (h_dentry->d_flags | |
906 | & DCACHE_NFSFS_RENAMED))) | |
907 | )) { | |
908 | int h_unhashed; | |
909 | ||
910 | h_unhashed = d_unhashed(h_dentry); | |
911 | spin_unlock(&h_dentry->d_lock); | |
912 | AuDbg("unhash 0x%x 0x%x, %pd %pd\n", | |
913 | unhashed, h_unhashed, dentry, h_dentry); | |
914 | goto err; | |
915 | } | |
916 | spin_unlock(&h_dentry->d_lock); | |
917 | ||
918 | err = au_do_h_d_reval(h_dentry, flags, dentry, bindex); | |
919 | if (unlikely(err)) | |
920 | /* do not goto err, to keep the errno */ | |
921 | break; | |
922 | ||
923 | /* todo: plink too? */ | |
924 | if (!do_udba) | |
925 | continue; | |
926 | ||
927 | /* UDBA tests */ | |
928 | if (unlikely(!!inode != d_is_positive(h_dentry))) | |
929 | goto err; | |
930 | ||
931 | h_inode = NULL; | |
932 | if (d_is_positive(h_dentry)) | |
933 | h_inode = d_inode(h_dentry); | |
934 | h_plus = plus; | |
935 | h_mode = mode; | |
936 | h_cached_inode = h_inode; | |
937 | if (h_inode) { | |
938 | h_mode = (h_inode->i_mode & S_IFMT); | |
939 | h_plus = (h_inode->i_nlink > 0); | |
940 | } | |
941 | if (inode && ibs <= bindex && bindex <= ibe) | |
942 | h_cached_inode = au_h_iptr(inode, bindex); | |
943 | ||
944 | if (!h_nfs) { | |
945 | if (unlikely(plus != h_plus && !tmpfile)) | |
946 | goto err; | |
947 | } else { | |
948 | if (unlikely(!(h_dentry->d_flags & DCACHE_NFSFS_RENAMED) | |
949 | && !is_root | |
950 | && !IS_ROOT(h_dentry) | |
951 | && unhashed != d_unhashed(h_dentry))) | |
952 | goto err; | |
953 | } | |
954 | if (unlikely(mode != h_mode | |
955 | || h_cached_inode != h_inode)) | |
956 | goto err; | |
957 | continue; | |
958 | ||
959 | err: | |
960 | err = -EINVAL; | |
961 | break; | |
962 | } | |
963 | ||
964 | AuTraceErr(err); | |
965 | return err; | |
966 | } | |
967 | ||
968 | /* todo: consolidate with do_refresh() and au_reval_for_attr() */ | |
969 | static int simple_reval_dpath(struct dentry *dentry, unsigned int sigen) | |
970 | { | |
971 | int err; | |
972 | struct dentry *parent; | |
973 | ||
974 | if (!au_digen_test(dentry, sigen)) | |
975 | return 0; | |
976 | ||
977 | parent = dget_parent(dentry); | |
978 | di_read_lock_parent(parent, AuLock_IR); | |
979 | AuDebugOn(au_digen_test(parent, sigen)); | |
980 | au_dbg_verify_gen(parent, sigen); | |
981 | err = au_refresh_dentry(dentry, parent); | |
982 | di_read_unlock(parent, AuLock_IR); | |
983 | dput(parent); | |
984 | AuTraceErr(err); | |
985 | return err; | |
986 | } | |
987 | ||
988 | int au_reval_dpath(struct dentry *dentry, unsigned int sigen) | |
989 | { | |
990 | int err; | |
991 | struct dentry *d, *parent; | |
992 | ||
993 | if (!au_ftest_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIR)) | |
994 | return simple_reval_dpath(dentry, sigen); | |
995 | ||
996 | /* slow loop, keep it simple and stupid */ | |
997 | /* cf: au_cpup_dirs() */ | |
998 | err = 0; | |
999 | parent = NULL; | |
1000 | while (au_digen_test(dentry, sigen)) { | |
1001 | d = dentry; | |
1002 | while (1) { | |
1003 | dput(parent); | |
1004 | parent = dget_parent(d); | |
1005 | if (!au_digen_test(parent, sigen)) | |
1006 | break; | |
1007 | d = parent; | |
1008 | } | |
1009 | ||
1010 | if (d != dentry) | |
1011 | di_write_lock_child2(d); | |
1012 | ||
1013 | /* someone might update our dentry while we were sleeping */ | |
1014 | if (au_digen_test(d, sigen)) { | |
1015 | /* | |
1016 | * todo: consolidate with simple_reval_dpath(), | |
1017 | * do_refresh() and au_reval_for_attr(). | |
1018 | */ | |
1019 | di_read_lock_parent(parent, AuLock_IR); | |
1020 | err = au_refresh_dentry(d, parent); | |
1021 | di_read_unlock(parent, AuLock_IR); | |
1022 | } | |
1023 | ||
1024 | if (d != dentry) | |
1025 | di_write_unlock(d); | |
1026 | dput(parent); | |
1027 | if (unlikely(err)) | |
1028 | break; | |
1029 | } | |
1030 | ||
1031 | return err; | |
1032 | } | |
1033 | ||
1034 | /* | |
1035 | * if valid returns 1, otherwise 0. | |
1036 | */ | |
1037 | static int aufs_d_revalidate(struct dentry *dentry, unsigned int flags) | |
1038 | { | |
1039 | int valid, err; | |
1040 | unsigned int sigen; | |
1041 | unsigned char do_udba, dirren; | |
1042 | struct super_block *sb; | |
1043 | struct inode *inode; | |
1044 | ||
1045 | /* todo: support rcu-walk? */ | |
1046 | if (flags & LOOKUP_RCU) | |
1047 | return -ECHILD; | |
1048 | ||
1049 | valid = 0; | |
1050 | if (unlikely(!au_di(dentry))) | |
1051 | goto out; | |
1052 | ||
1053 | valid = 1; | |
1054 | sb = dentry->d_sb; | |
1055 | /* | |
1056 | * todo: very ugly | |
1057 | * i_mutex of parent dir may be held, | |
1058 | * but we should not return 'invalid' due to busy. | |
1059 | */ | |
1060 | err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW | AuLock_NOPLM); | |
1061 | if (unlikely(err)) { | |
1062 | valid = err; | |
1063 | AuTraceErr(err); | |
1064 | goto out; | |
1065 | } | |
1066 | inode = NULL; | |
1067 | if (d_really_is_positive(dentry)) | |
1068 | inode = d_inode(dentry); | |
1069 | if (unlikely(inode && au_is_bad_inode(inode))) { | |
1070 | err = -EINVAL; | |
1071 | AuTraceErr(err); | |
1072 | goto out_dgrade; | |
1073 | } | |
1074 | if (unlikely(au_dbrange_test(dentry))) { | |
1075 | err = -EINVAL; | |
1076 | AuTraceErr(err); | |
1077 | goto out_dgrade; | |
1078 | } | |
1079 | ||
1080 | sigen = au_sigen(sb); | |
1081 | if (au_digen_test(dentry, sigen)) { | |
1082 | AuDebugOn(IS_ROOT(dentry)); | |
1083 | err = au_reval_dpath(dentry, sigen); | |
1084 | if (unlikely(err)) { | |
1085 | AuTraceErr(err); | |
1086 | goto out_dgrade; | |
1087 | } | |
1088 | } | |
1089 | di_downgrade_lock(dentry, AuLock_IR); | |
1090 | ||
1091 | err = -EINVAL; | |
1092 | if (!(flags & (LOOKUP_OPEN | LOOKUP_EMPTY)) | |
1093 | && inode | |
1094 | && !(inode->i_state && I_LINKABLE) | |
1095 | && (IS_DEADDIR(inode) || !inode->i_nlink)) { | |
1096 | AuTraceErr(err); | |
1097 | goto out_inval; | |
1098 | } | |
1099 | ||
1100 | do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE); | |
1101 | if (do_udba && inode) { | |
1102 | aufs_bindex_t btop = au_ibtop(inode); | |
1103 | struct inode *h_inode; | |
1104 | ||
1105 | if (btop >= 0) { | |
1106 | h_inode = au_h_iptr(inode, btop); | |
1107 | if (h_inode && au_test_higen(inode, h_inode)) { | |
1108 | AuTraceErr(err); | |
1109 | goto out_inval; | |
1110 | } | |
1111 | } | |
1112 | } | |
1113 | ||
1114 | dirren = !!au_opt_test(au_mntflags(sb), DIRREN); | |
1115 | err = h_d_revalidate(dentry, inode, flags, do_udba, dirren); | |
1116 | if (unlikely(!err && do_udba && au_dbtop(dentry) < 0)) { | |
1117 | err = -EIO; | |
1118 | AuDbg("both of real entry and whiteout found, %p, err %d\n", | |
1119 | dentry, err); | |
1120 | } | |
1121 | goto out_inval; | |
1122 | ||
1123 | out_dgrade: | |
1124 | di_downgrade_lock(dentry, AuLock_IR); | |
1125 | out_inval: | |
1126 | aufs_read_unlock(dentry, AuLock_IR); | |
1127 | AuTraceErr(err); | |
1128 | valid = !err; | |
1129 | out: | |
1130 | if (!valid) { | |
1131 | AuDbg("%pd invalid, %d\n", dentry, valid); | |
1132 | d_drop(dentry); | |
1133 | } | |
1134 | return valid; | |
1135 | } | |
1136 | ||
1137 | static void aufs_d_release(struct dentry *dentry) | |
1138 | { | |
1139 | if (au_di(dentry)) { | |
1140 | au_di_fin(dentry); | |
1141 | au_hn_di_reinit(dentry); | |
1142 | } | |
1143 | } | |
1144 | ||
1145 | const struct dentry_operations aufs_dop = { | |
1146 | .d_revalidate = aufs_d_revalidate, | |
1147 | .d_weak_revalidate = aufs_d_revalidate, | |
1148 | .d_release = aufs_d_release | |
1149 | }; | |
1150 | ||
1151 | /* aufs_dop without d_revalidate */ | |
1152 | const struct dentry_operations aufs_dop_noreval = { | |
1153 | .d_release = aufs_d_release | |
1154 | }; |