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Commit | Line | Data |
---|---|---|
e9be9d5e MS |
1 | /* |
2 | * | |
3 | * Copyright (C) 2011 Novell Inc. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License version 2 as published by | |
7 | * the Free Software Foundation. | |
8 | */ | |
9 | ||
10 | #include <linux/fs.h> | |
11 | #include <linux/namei.h> | |
12 | #include <linux/xattr.h> | |
13 | #include <linux/security.h> | |
14 | #include <linux/cred.h> | |
38b25697 MS |
15 | #include <linux/posix_acl.h> |
16 | #include <linux/posix_acl_xattr.h> | |
e9be9d5e MS |
17 | #include "overlayfs.h" |
18 | ||
19 | void ovl_cleanup(struct inode *wdir, struct dentry *wdentry) | |
20 | { | |
21 | int err; | |
22 | ||
23 | dget(wdentry); | |
e36cb0b8 | 24 | if (d_is_dir(wdentry)) |
e9be9d5e MS |
25 | err = ovl_do_rmdir(wdir, wdentry); |
26 | else | |
27 | err = ovl_do_unlink(wdir, wdentry); | |
28 | dput(wdentry); | |
29 | ||
30 | if (err) { | |
31 | pr_err("overlayfs: cleanup of '%pd2' failed (%i)\n", | |
32 | wdentry, err); | |
33 | } | |
34 | } | |
35 | ||
36 | struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry) | |
37 | { | |
38 | struct dentry *temp; | |
39 | char name[20]; | |
40 | ||
41 | snprintf(name, sizeof(name), "#%lx", (unsigned long) dentry); | |
42 | ||
43 | temp = lookup_one_len(name, workdir, strlen(name)); | |
44 | if (!IS_ERR(temp) && temp->d_inode) { | |
45 | pr_err("overlayfs: workdir/%s already exists\n", name); | |
46 | dput(temp); | |
47 | temp = ERR_PTR(-EIO); | |
48 | } | |
49 | ||
50 | return temp; | |
51 | } | |
52 | ||
53 | /* caller holds i_mutex on workdir */ | |
54 | static struct dentry *ovl_whiteout(struct dentry *workdir, | |
55 | struct dentry *dentry) | |
56 | { | |
57 | int err; | |
58 | struct dentry *whiteout; | |
59 | struct inode *wdir = workdir->d_inode; | |
60 | ||
61 | whiteout = ovl_lookup_temp(workdir, dentry); | |
62 | if (IS_ERR(whiteout)) | |
63 | return whiteout; | |
64 | ||
65 | err = ovl_do_whiteout(wdir, whiteout); | |
66 | if (err) { | |
67 | dput(whiteout); | |
68 | whiteout = ERR_PTR(err); | |
69 | } | |
70 | ||
71 | return whiteout; | |
72 | } | |
73 | ||
74 | int ovl_create_real(struct inode *dir, struct dentry *newdentry, | |
75 | struct kstat *stat, const char *link, | |
76 | struct dentry *hardlink, bool debug) | |
77 | { | |
78 | int err; | |
79 | ||
80 | if (newdentry->d_inode) | |
81 | return -ESTALE; | |
82 | ||
83 | if (hardlink) { | |
84 | err = ovl_do_link(hardlink, dir, newdentry, debug); | |
85 | } else { | |
86 | switch (stat->mode & S_IFMT) { | |
87 | case S_IFREG: | |
88 | err = ovl_do_create(dir, newdentry, stat->mode, debug); | |
89 | break; | |
90 | ||
91 | case S_IFDIR: | |
92 | err = ovl_do_mkdir(dir, newdentry, stat->mode, debug); | |
93 | break; | |
94 | ||
95 | case S_IFCHR: | |
96 | case S_IFBLK: | |
97 | case S_IFIFO: | |
98 | case S_IFSOCK: | |
99 | err = ovl_do_mknod(dir, newdentry, | |
100 | stat->mode, stat->rdev, debug); | |
101 | break; | |
102 | ||
103 | case S_IFLNK: | |
104 | err = ovl_do_symlink(dir, newdentry, link, debug); | |
105 | break; | |
106 | ||
107 | default: | |
108 | err = -EPERM; | |
109 | } | |
110 | } | |
111 | if (!err && WARN_ON(!newdentry->d_inode)) { | |
112 | /* | |
113 | * Not quite sure if non-instantiated dentry is legal or not. | |
114 | * VFS doesn't seem to care so check and warn here. | |
115 | */ | |
116 | err = -ENOENT; | |
117 | } | |
118 | return err; | |
119 | } | |
120 | ||
121 | static int ovl_set_opaque(struct dentry *upperdentry) | |
122 | { | |
cead89bb | 123 | return ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0); |
e9be9d5e MS |
124 | } |
125 | ||
126 | static void ovl_remove_opaque(struct dentry *upperdentry) | |
127 | { | |
128 | int err; | |
129 | ||
cead89bb | 130 | err = ovl_do_removexattr(upperdentry, OVL_XATTR_OPAQUE); |
e9be9d5e MS |
131 | if (err) { |
132 | pr_warn("overlayfs: failed to remove opaque from '%s' (%i)\n", | |
133 | upperdentry->d_name.name, err); | |
134 | } | |
135 | } | |
136 | ||
137 | static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry, | |
138 | struct kstat *stat) | |
139 | { | |
140 | int err; | |
141 | enum ovl_path_type type; | |
142 | struct path realpath; | |
1175b6b8 | 143 | const struct cred *old_cred; |
e9be9d5e MS |
144 | |
145 | type = ovl_path_real(dentry, &realpath); | |
1175b6b8 | 146 | old_cred = ovl_override_creds(dentry->d_sb); |
e9be9d5e | 147 | err = vfs_getattr(&realpath, stat); |
1175b6b8 | 148 | revert_creds(old_cred); |
e9be9d5e MS |
149 | if (err) |
150 | return err; | |
151 | ||
152 | stat->dev = dentry->d_sb->s_dev; | |
153 | stat->ino = dentry->d_inode->i_ino; | |
154 | ||
155 | /* | |
156 | * It's probably not worth it to count subdirs to get the | |
157 | * correct link count. nlink=1 seems to pacify 'find' and | |
158 | * other utilities. | |
159 | */ | |
1afaba1e | 160 | if (OVL_TYPE_MERGE(type)) |
e9be9d5e MS |
161 | stat->nlink = 1; |
162 | ||
163 | return 0; | |
164 | } | |
165 | ||
72e48481 VG |
166 | /* Common operations required to be done after creation of file on upper */ |
167 | static void ovl_instantiate(struct dentry *dentry, struct inode *inode, | |
51f7e52d | 168 | struct dentry *newdentry, bool hardlink) |
72e48481 VG |
169 | { |
170 | ovl_dentry_version_inc(dentry->d_parent); | |
171 | ovl_dentry_update(dentry, newdentry); | |
51f7e52d MS |
172 | if (!hardlink) { |
173 | ovl_inode_update(inode, d_inode(newdentry)); | |
174 | ovl_copyattr(newdentry->d_inode, inode); | |
175 | } else { | |
176 | WARN_ON(ovl_inode_real(inode, NULL) != d_inode(newdentry)); | |
177 | inc_nlink(inode); | |
178 | } | |
72e48481 VG |
179 | d_instantiate(dentry, inode); |
180 | } | |
181 | ||
e9be9d5e MS |
182 | static int ovl_create_upper(struct dentry *dentry, struct inode *inode, |
183 | struct kstat *stat, const char *link, | |
184 | struct dentry *hardlink) | |
185 | { | |
186 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
187 | struct inode *udir = upperdir->d_inode; | |
188 | struct dentry *newdentry; | |
189 | int err; | |
190 | ||
38b25697 MS |
191 | if (!hardlink && !IS_POSIXACL(udir)) |
192 | stat->mode &= ~current_umask(); | |
193 | ||
5955102c | 194 | inode_lock_nested(udir, I_MUTEX_PARENT); |
e9be9d5e MS |
195 | newdentry = lookup_one_len(dentry->d_name.name, upperdir, |
196 | dentry->d_name.len); | |
197 | err = PTR_ERR(newdentry); | |
198 | if (IS_ERR(newdentry)) | |
199 | goto out_unlock; | |
200 | err = ovl_create_real(udir, newdentry, stat, link, hardlink, false); | |
201 | if (err) | |
202 | goto out_dput; | |
203 | ||
51f7e52d | 204 | ovl_instantiate(dentry, inode, newdentry, !!hardlink); |
e9be9d5e MS |
205 | newdentry = NULL; |
206 | out_dput: | |
207 | dput(newdentry); | |
208 | out_unlock: | |
5955102c | 209 | inode_unlock(udir); |
e9be9d5e MS |
210 | return err; |
211 | } | |
212 | ||
213 | static int ovl_lock_rename_workdir(struct dentry *workdir, | |
214 | struct dentry *upperdir) | |
215 | { | |
216 | /* Workdir should not be the same as upperdir */ | |
217 | if (workdir == upperdir) | |
218 | goto err; | |
219 | ||
220 | /* Workdir should not be subdir of upperdir and vice versa */ | |
221 | if (lock_rename(workdir, upperdir) != NULL) | |
222 | goto err_unlock; | |
223 | ||
224 | return 0; | |
225 | ||
226 | err_unlock: | |
227 | unlock_rename(workdir, upperdir); | |
228 | err: | |
229 | pr_err("overlayfs: failed to lock workdir+upperdir\n"); | |
230 | return -EIO; | |
231 | } | |
232 | ||
233 | static struct dentry *ovl_clear_empty(struct dentry *dentry, | |
234 | struct list_head *list) | |
235 | { | |
236 | struct dentry *workdir = ovl_workdir(dentry); | |
237 | struct inode *wdir = workdir->d_inode; | |
238 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
239 | struct inode *udir = upperdir->d_inode; | |
240 | struct path upperpath; | |
241 | struct dentry *upper; | |
242 | struct dentry *opaquedir; | |
243 | struct kstat stat; | |
244 | int err; | |
245 | ||
cc6f67bc MS |
246 | if (WARN_ON(!workdir)) |
247 | return ERR_PTR(-EROFS); | |
248 | ||
e9be9d5e MS |
249 | err = ovl_lock_rename_workdir(workdir, upperdir); |
250 | if (err) | |
251 | goto out; | |
252 | ||
253 | ovl_path_upper(dentry, &upperpath); | |
254 | err = vfs_getattr(&upperpath, &stat); | |
255 | if (err) | |
256 | goto out_unlock; | |
257 | ||
258 | err = -ESTALE; | |
259 | if (!S_ISDIR(stat.mode)) | |
260 | goto out_unlock; | |
261 | upper = upperpath.dentry; | |
262 | if (upper->d_parent->d_inode != udir) | |
263 | goto out_unlock; | |
264 | ||
265 | opaquedir = ovl_lookup_temp(workdir, dentry); | |
266 | err = PTR_ERR(opaquedir); | |
267 | if (IS_ERR(opaquedir)) | |
268 | goto out_unlock; | |
269 | ||
270 | err = ovl_create_real(wdir, opaquedir, &stat, NULL, NULL, true); | |
271 | if (err) | |
272 | goto out_dput; | |
273 | ||
274 | err = ovl_copy_xattr(upper, opaquedir); | |
275 | if (err) | |
276 | goto out_cleanup; | |
277 | ||
278 | err = ovl_set_opaque(opaquedir); | |
279 | if (err) | |
280 | goto out_cleanup; | |
281 | ||
5955102c | 282 | inode_lock(opaquedir->d_inode); |
e9be9d5e | 283 | err = ovl_set_attr(opaquedir, &stat); |
5955102c | 284 | inode_unlock(opaquedir->d_inode); |
e9be9d5e MS |
285 | if (err) |
286 | goto out_cleanup; | |
287 | ||
288 | err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE); | |
289 | if (err) | |
290 | goto out_cleanup; | |
291 | ||
292 | ovl_cleanup_whiteouts(upper, list); | |
293 | ovl_cleanup(wdir, upper); | |
294 | unlock_rename(workdir, upperdir); | |
295 | ||
296 | /* dentry's upper doesn't match now, get rid of it */ | |
297 | d_drop(dentry); | |
298 | ||
299 | return opaquedir; | |
300 | ||
301 | out_cleanup: | |
302 | ovl_cleanup(wdir, opaquedir); | |
303 | out_dput: | |
304 | dput(opaquedir); | |
305 | out_unlock: | |
306 | unlock_rename(workdir, upperdir); | |
307 | out: | |
308 | return ERR_PTR(err); | |
309 | } | |
310 | ||
a105d685 | 311 | static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry) |
e9be9d5e MS |
312 | { |
313 | int err; | |
314 | struct dentry *ret = NULL; | |
30c17ebf | 315 | enum ovl_path_type type = ovl_path_type(dentry); |
e9be9d5e MS |
316 | LIST_HEAD(list); |
317 | ||
318 | err = ovl_check_empty_dir(dentry, &list); | |
30c17ebf | 319 | if (err) { |
e9be9d5e | 320 | ret = ERR_PTR(err); |
30c17ebf | 321 | goto out_free; |
a105d685 | 322 | } |
e9be9d5e | 323 | |
30c17ebf MS |
324 | /* |
325 | * When removing an empty opaque directory, then it makes no sense to | |
326 | * replace it with an exact replica of itself. | |
327 | * | |
328 | * If no upperdentry then skip clearing whiteouts. | |
329 | * | |
330 | * Can race with copy-up, since we don't hold the upperdir mutex. | |
331 | * Doesn't matter, since copy-up can't create a non-empty directory | |
332 | * from an empty one. | |
333 | */ | |
334 | if (OVL_TYPE_UPPER(type) && OVL_TYPE_MERGE(type)) | |
335 | ret = ovl_clear_empty(dentry, &list); | |
336 | ||
337 | out_free: | |
e9be9d5e MS |
338 | ovl_cache_free(&list); |
339 | ||
340 | return ret; | |
341 | } | |
342 | ||
38b25697 MS |
343 | static int ovl_set_upper_acl(struct dentry *upperdentry, const char *name, |
344 | const struct posix_acl *acl) | |
345 | { | |
346 | void *buffer; | |
347 | size_t size; | |
348 | int err; | |
349 | ||
350 | if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl) | |
351 | return 0; | |
352 | ||
353 | size = posix_acl_to_xattr(NULL, acl, NULL, 0); | |
354 | buffer = kmalloc(size, GFP_KERNEL); | |
355 | if (!buffer) | |
356 | return -ENOMEM; | |
357 | ||
358 | size = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); | |
359 | err = size; | |
360 | if (err < 0) | |
361 | goto out_free; | |
362 | ||
363 | err = vfs_setxattr(upperdentry, name, buffer, size, XATTR_CREATE); | |
364 | out_free: | |
365 | kfree(buffer); | |
366 | return err; | |
367 | } | |
368 | ||
e9be9d5e MS |
369 | static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, |
370 | struct kstat *stat, const char *link, | |
371 | struct dentry *hardlink) | |
372 | { | |
373 | struct dentry *workdir = ovl_workdir(dentry); | |
374 | struct inode *wdir = workdir->d_inode; | |
375 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
376 | struct inode *udir = upperdir->d_inode; | |
377 | struct dentry *upper; | |
378 | struct dentry *newdentry; | |
379 | int err; | |
38b25697 | 380 | struct posix_acl *acl, *default_acl; |
e9be9d5e | 381 | |
cc6f67bc MS |
382 | if (WARN_ON(!workdir)) |
383 | return -EROFS; | |
384 | ||
38b25697 MS |
385 | if (!hardlink) { |
386 | err = posix_acl_create(dentry->d_parent->d_inode, | |
387 | &stat->mode, &default_acl, &acl); | |
388 | if (err) | |
389 | return err; | |
390 | } | |
391 | ||
e9be9d5e MS |
392 | err = ovl_lock_rename_workdir(workdir, upperdir); |
393 | if (err) | |
394 | goto out; | |
395 | ||
396 | newdentry = ovl_lookup_temp(workdir, dentry); | |
397 | err = PTR_ERR(newdentry); | |
398 | if (IS_ERR(newdentry)) | |
399 | goto out_unlock; | |
400 | ||
401 | upper = lookup_one_len(dentry->d_name.name, upperdir, | |
402 | dentry->d_name.len); | |
403 | err = PTR_ERR(upper); | |
404 | if (IS_ERR(upper)) | |
405 | goto out_dput; | |
406 | ||
407 | err = ovl_create_real(wdir, newdentry, stat, link, hardlink, true); | |
408 | if (err) | |
409 | goto out_dput2; | |
410 | ||
bb0d2b8a MS |
411 | /* |
412 | * mode could have been mutilated due to umask (e.g. sgid directory) | |
413 | */ | |
51f7e52d MS |
414 | if (!hardlink && |
415 | !S_ISLNK(stat->mode) && newdentry->d_inode->i_mode != stat->mode) { | |
bb0d2b8a MS |
416 | struct iattr attr = { |
417 | .ia_valid = ATTR_MODE, | |
418 | .ia_mode = stat->mode, | |
419 | }; | |
420 | inode_lock(newdentry->d_inode); | |
421 | err = notify_change(newdentry, &attr, NULL); | |
422 | inode_unlock(newdentry->d_inode); | |
423 | if (err) | |
424 | goto out_cleanup; | |
425 | } | |
38b25697 MS |
426 | if (!hardlink) { |
427 | err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_ACCESS, | |
428 | acl); | |
429 | if (err) | |
430 | goto out_cleanup; | |
431 | ||
432 | err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_DEFAULT, | |
433 | default_acl); | |
434 | if (err) | |
435 | goto out_cleanup; | |
436 | } | |
bb0d2b8a | 437 | |
51f7e52d | 438 | if (!hardlink && S_ISDIR(stat->mode)) { |
e9be9d5e MS |
439 | err = ovl_set_opaque(newdentry); |
440 | if (err) | |
441 | goto out_cleanup; | |
442 | ||
443 | err = ovl_do_rename(wdir, newdentry, udir, upper, | |
444 | RENAME_EXCHANGE); | |
445 | if (err) | |
446 | goto out_cleanup; | |
447 | ||
448 | ovl_cleanup(wdir, upper); | |
449 | } else { | |
450 | err = ovl_do_rename(wdir, newdentry, udir, upper, 0); | |
451 | if (err) | |
452 | goto out_cleanup; | |
453 | } | |
51f7e52d | 454 | ovl_instantiate(dentry, inode, newdentry, !!hardlink); |
e9be9d5e MS |
455 | newdentry = NULL; |
456 | out_dput2: | |
457 | dput(upper); | |
458 | out_dput: | |
459 | dput(newdentry); | |
460 | out_unlock: | |
461 | unlock_rename(workdir, upperdir); | |
462 | out: | |
38b25697 MS |
463 | if (!hardlink) { |
464 | posix_acl_release(acl); | |
465 | posix_acl_release(default_acl); | |
466 | } | |
e9be9d5e MS |
467 | return err; |
468 | ||
469 | out_cleanup: | |
470 | ovl_cleanup(wdir, newdentry); | |
471 | goto out_dput2; | |
472 | } | |
473 | ||
51f7e52d MS |
474 | static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, |
475 | struct kstat *stat, const char *link, | |
476 | struct dentry *hardlink) | |
e9be9d5e MS |
477 | { |
478 | int err; | |
1175b6b8 VG |
479 | const struct cred *old_cred; |
480 | struct cred *override_cred; | |
e9be9d5e MS |
481 | |
482 | err = ovl_copy_up(dentry->d_parent); | |
483 | if (err) | |
51f7e52d | 484 | return err; |
bb0d2b8a | 485 | |
1175b6b8 VG |
486 | old_cred = ovl_override_creds(dentry->d_sb); |
487 | err = -ENOMEM; | |
488 | override_cred = prepare_creds(); | |
489 | if (override_cred) { | |
bb0d2b8a MS |
490 | override_cred->fsuid = inode->i_uid; |
491 | override_cred->fsgid = inode->i_gid; | |
1175b6b8 VG |
492 | put_cred(override_creds(override_cred)); |
493 | put_cred(override_cred); | |
494 | ||
495 | if (!ovl_dentry_is_opaque(dentry)) | |
51f7e52d | 496 | err = ovl_create_upper(dentry, inode, stat, link, |
1175b6b8 VG |
497 | hardlink); |
498 | else | |
51f7e52d | 499 | err = ovl_create_over_whiteout(dentry, inode, stat, |
1175b6b8 | 500 | link, hardlink); |
e9be9d5e | 501 | } |
1175b6b8 | 502 | revert_creds(old_cred); |
bb0d2b8a MS |
503 | if (!err) { |
504 | struct inode *realinode = d_inode(ovl_dentry_upper(dentry)); | |
505 | ||
506 | WARN_ON(inode->i_mode != realinode->i_mode); | |
507 | WARN_ON(!uid_eq(inode->i_uid, realinode->i_uid)); | |
508 | WARN_ON(!gid_eq(inode->i_gid, realinode->i_gid)); | |
bb0d2b8a | 509 | } |
e9be9d5e MS |
510 | return err; |
511 | } | |
512 | ||
513 | static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, | |
514 | const char *link) | |
515 | { | |
516 | int err; | |
51f7e52d MS |
517 | struct inode *inode; |
518 | struct kstat stat = { | |
519 | .rdev = rdev, | |
520 | }; | |
e9be9d5e MS |
521 | |
522 | err = ovl_want_write(dentry); | |
51f7e52d MS |
523 | if (err) |
524 | goto out; | |
525 | ||
526 | err = -ENOMEM; | |
527 | inode = ovl_new_inode(dentry->d_sb, mode); | |
528 | if (!inode) | |
529 | goto out_drop_write; | |
530 | ||
531 | inode_init_owner(inode, dentry->d_parent->d_inode, mode); | |
532 | stat.mode = inode->i_mode; | |
533 | ||
534 | err = ovl_create_or_link(dentry, inode, &stat, link, NULL); | |
535 | if (err) | |
536 | iput(inode); | |
e9be9d5e | 537 | |
51f7e52d MS |
538 | out_drop_write: |
539 | ovl_drop_write(dentry); | |
540 | out: | |
e9be9d5e MS |
541 | return err; |
542 | } | |
543 | ||
544 | static int ovl_create(struct inode *dir, struct dentry *dentry, umode_t mode, | |
545 | bool excl) | |
546 | { | |
547 | return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL); | |
548 | } | |
549 | ||
550 | static int ovl_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) | |
551 | { | |
552 | return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL); | |
553 | } | |
554 | ||
555 | static int ovl_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, | |
556 | dev_t rdev) | |
557 | { | |
558 | /* Don't allow creation of "whiteout" on overlay */ | |
559 | if (S_ISCHR(mode) && rdev == WHITEOUT_DEV) | |
560 | return -EPERM; | |
561 | ||
562 | return ovl_create_object(dentry, mode, rdev, NULL); | |
563 | } | |
564 | ||
565 | static int ovl_symlink(struct inode *dir, struct dentry *dentry, | |
566 | const char *link) | |
567 | { | |
568 | return ovl_create_object(dentry, S_IFLNK, 0, link); | |
569 | } | |
570 | ||
571 | static int ovl_link(struct dentry *old, struct inode *newdir, | |
572 | struct dentry *new) | |
573 | { | |
574 | int err; | |
51f7e52d | 575 | struct inode *inode; |
e9be9d5e MS |
576 | |
577 | err = ovl_want_write(old); | |
578 | if (err) | |
579 | goto out; | |
580 | ||
581 | err = ovl_copy_up(old); | |
582 | if (err) | |
583 | goto out_drop_write; | |
584 | ||
51f7e52d MS |
585 | inode = d_inode(old); |
586 | ihold(inode); | |
587 | ||
588 | err = ovl_create_or_link(new, inode, NULL, NULL, ovl_dentry_upper(old)); | |
589 | if (err) | |
590 | iput(inode); | |
e9be9d5e MS |
591 | |
592 | out_drop_write: | |
593 | ovl_drop_write(old); | |
594 | out: | |
595 | return err; | |
596 | } | |
597 | ||
a105d685 | 598 | static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir) |
e9be9d5e MS |
599 | { |
600 | struct dentry *workdir = ovl_workdir(dentry); | |
601 | struct inode *wdir = workdir->d_inode; | |
602 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
603 | struct inode *udir = upperdir->d_inode; | |
604 | struct dentry *whiteout; | |
605 | struct dentry *upper; | |
606 | struct dentry *opaquedir = NULL; | |
607 | int err; | |
cfc9fde0 | 608 | int flags = 0; |
e9be9d5e | 609 | |
cc6f67bc MS |
610 | if (WARN_ON(!workdir)) |
611 | return -EROFS; | |
612 | ||
d377c5eb | 613 | if (is_dir) { |
30c17ebf MS |
614 | opaquedir = ovl_check_empty_and_clear(dentry); |
615 | err = PTR_ERR(opaquedir); | |
616 | if (IS_ERR(opaquedir)) | |
617 | goto out; | |
e9be9d5e MS |
618 | } |
619 | ||
620 | err = ovl_lock_rename_workdir(workdir, upperdir); | |
621 | if (err) | |
622 | goto out_dput; | |
623 | ||
cfc9fde0 MP |
624 | upper = lookup_one_len(dentry->d_name.name, upperdir, |
625 | dentry->d_name.len); | |
626 | err = PTR_ERR(upper); | |
627 | if (IS_ERR(upper)) | |
e9be9d5e MS |
628 | goto out_unlock; |
629 | ||
cfc9fde0 MP |
630 | err = -ESTALE; |
631 | if ((opaquedir && upper != opaquedir) || | |
632 | (!opaquedir && ovl_dentry_upper(dentry) && | |
633 | upper != ovl_dentry_upper(dentry))) { | |
634 | goto out_dput_upper; | |
635 | } | |
e9be9d5e | 636 | |
cfc9fde0 MP |
637 | whiteout = ovl_whiteout(workdir, dentry); |
638 | err = PTR_ERR(whiteout); | |
639 | if (IS_ERR(whiteout)) | |
640 | goto out_dput_upper; | |
e9be9d5e | 641 | |
cfc9fde0 MP |
642 | if (d_is_dir(upper)) |
643 | flags = RENAME_EXCHANGE; | |
e9be9d5e | 644 | |
cfc9fde0 MP |
645 | err = ovl_do_rename(wdir, whiteout, udir, upper, flags); |
646 | if (err) | |
647 | goto kill_whiteout; | |
648 | if (flags) | |
649 | ovl_cleanup(wdir, upper); | |
e9be9d5e | 650 | |
e9be9d5e MS |
651 | ovl_dentry_version_inc(dentry->d_parent); |
652 | out_d_drop: | |
653 | d_drop(dentry); | |
654 | dput(whiteout); | |
cfc9fde0 MP |
655 | out_dput_upper: |
656 | dput(upper); | |
e9be9d5e MS |
657 | out_unlock: |
658 | unlock_rename(workdir, upperdir); | |
659 | out_dput: | |
660 | dput(opaquedir); | |
661 | out: | |
662 | return err; | |
663 | ||
664 | kill_whiteout: | |
665 | ovl_cleanup(wdir, whiteout); | |
666 | goto out_d_drop; | |
667 | } | |
668 | ||
669 | static int ovl_remove_upper(struct dentry *dentry, bool is_dir) | |
670 | { | |
671 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
672 | struct inode *dir = upperdir->d_inode; | |
11f37104 | 673 | struct dentry *upper; |
e9be9d5e MS |
674 | int err; |
675 | ||
5955102c | 676 | inode_lock_nested(dir, I_MUTEX_PARENT); |
11f37104 MS |
677 | upper = lookup_one_len(dentry->d_name.name, upperdir, |
678 | dentry->d_name.len); | |
679 | err = PTR_ERR(upper); | |
680 | if (IS_ERR(upper)) | |
681 | goto out_unlock; | |
682 | ||
e9be9d5e | 683 | err = -ESTALE; |
11f37104 | 684 | if (upper == ovl_dentry_upper(dentry)) { |
e9be9d5e MS |
685 | if (is_dir) |
686 | err = vfs_rmdir(dir, upper); | |
687 | else | |
688 | err = vfs_unlink(dir, upper, NULL); | |
e9be9d5e MS |
689 | ovl_dentry_version_inc(dentry->d_parent); |
690 | } | |
11f37104 | 691 | dput(upper); |
e9be9d5e MS |
692 | |
693 | /* | |
694 | * Keeping this dentry hashed would mean having to release | |
695 | * upperpath/lowerpath, which could only be done if we are the | |
696 | * sole user of this dentry. Too tricky... Just unhash for | |
697 | * now. | |
698 | */ | |
ce9113bb RW |
699 | if (!err) |
700 | d_drop(dentry); | |
11f37104 | 701 | out_unlock: |
5955102c | 702 | inode_unlock(dir); |
e9be9d5e MS |
703 | |
704 | return err; | |
705 | } | |
706 | ||
707 | static inline int ovl_check_sticky(struct dentry *dentry) | |
708 | { | |
709 | struct inode *dir = ovl_dentry_real(dentry->d_parent)->d_inode; | |
710 | struct inode *inode = ovl_dentry_real(dentry)->d_inode; | |
711 | ||
712 | if (check_sticky(dir, inode)) | |
713 | return -EPERM; | |
714 | ||
715 | return 0; | |
716 | } | |
717 | ||
718 | static int ovl_do_remove(struct dentry *dentry, bool is_dir) | |
719 | { | |
720 | enum ovl_path_type type; | |
721 | int err; | |
1175b6b8 VG |
722 | const struct cred *old_cred; |
723 | ||
e9be9d5e MS |
724 | |
725 | err = ovl_check_sticky(dentry); | |
726 | if (err) | |
727 | goto out; | |
728 | ||
729 | err = ovl_want_write(dentry); | |
730 | if (err) | |
731 | goto out; | |
732 | ||
733 | err = ovl_copy_up(dentry->d_parent); | |
734 | if (err) | |
735 | goto out_drop_write; | |
736 | ||
737 | type = ovl_path_type(dentry); | |
e9be9d5e | 738 | |
1175b6b8 VG |
739 | old_cred = ovl_override_creds(dentry->d_sb); |
740 | if (OVL_TYPE_PURE_UPPER(type)) | |
741 | err = ovl_remove_upper(dentry, is_dir); | |
742 | else | |
a105d685 | 743 | err = ovl_remove_and_whiteout(dentry, is_dir); |
1175b6b8 | 744 | revert_creds(old_cred); |
dbc816d0 MS |
745 | if (!err) { |
746 | if (is_dir) | |
747 | clear_nlink(dentry->d_inode); | |
748 | else | |
749 | drop_nlink(dentry->d_inode); | |
750 | } | |
e9be9d5e MS |
751 | out_drop_write: |
752 | ovl_drop_write(dentry); | |
753 | out: | |
754 | return err; | |
755 | } | |
756 | ||
757 | static int ovl_unlink(struct inode *dir, struct dentry *dentry) | |
758 | { | |
759 | return ovl_do_remove(dentry, false); | |
760 | } | |
761 | ||
762 | static int ovl_rmdir(struct inode *dir, struct dentry *dentry) | |
763 | { | |
764 | return ovl_do_remove(dentry, true); | |
765 | } | |
766 | ||
767 | static int ovl_rename2(struct inode *olddir, struct dentry *old, | |
768 | struct inode *newdir, struct dentry *new, | |
769 | unsigned int flags) | |
770 | { | |
771 | int err; | |
772 | enum ovl_path_type old_type; | |
773 | enum ovl_path_type new_type; | |
774 | struct dentry *old_upperdir; | |
775 | struct dentry *new_upperdir; | |
776 | struct dentry *olddentry; | |
777 | struct dentry *newdentry; | |
778 | struct dentry *trap; | |
779 | bool old_opaque; | |
780 | bool new_opaque; | |
e9be9d5e MS |
781 | bool cleanup_whiteout = false; |
782 | bool overwrite = !(flags & RENAME_EXCHANGE); | |
e36cb0b8 | 783 | bool is_dir = d_is_dir(old); |
e9be9d5e MS |
784 | bool new_is_dir = false; |
785 | struct dentry *opaquedir = NULL; | |
786 | const struct cred *old_cred = NULL; | |
e9be9d5e MS |
787 | |
788 | err = -EINVAL; | |
789 | if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) | |
790 | goto out; | |
791 | ||
792 | flags &= ~RENAME_NOREPLACE; | |
793 | ||
794 | err = ovl_check_sticky(old); | |
795 | if (err) | |
796 | goto out; | |
797 | ||
798 | /* Don't copy up directory trees */ | |
799 | old_type = ovl_path_type(old); | |
800 | err = -EXDEV; | |
1afaba1e | 801 | if (OVL_TYPE_MERGE_OR_LOWER(old_type) && is_dir) |
e9be9d5e MS |
802 | goto out; |
803 | ||
804 | if (new->d_inode) { | |
805 | err = ovl_check_sticky(new); | |
806 | if (err) | |
807 | goto out; | |
808 | ||
e36cb0b8 | 809 | if (d_is_dir(new)) |
e9be9d5e MS |
810 | new_is_dir = true; |
811 | ||
812 | new_type = ovl_path_type(new); | |
813 | err = -EXDEV; | |
1afaba1e | 814 | if (!overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) |
e9be9d5e MS |
815 | goto out; |
816 | ||
817 | err = 0; | |
1afaba1e | 818 | if (!OVL_TYPE_UPPER(new_type) && !OVL_TYPE_UPPER(old_type)) { |
e9be9d5e MS |
819 | if (ovl_dentry_lower(old)->d_inode == |
820 | ovl_dentry_lower(new)->d_inode) | |
821 | goto out; | |
822 | } | |
1afaba1e | 823 | if (OVL_TYPE_UPPER(new_type) && OVL_TYPE_UPPER(old_type)) { |
e9be9d5e MS |
824 | if (ovl_dentry_upper(old)->d_inode == |
825 | ovl_dentry_upper(new)->d_inode) | |
826 | goto out; | |
827 | } | |
828 | } else { | |
829 | if (ovl_dentry_is_opaque(new)) | |
1afaba1e | 830 | new_type = __OVL_PATH_UPPER; |
e9be9d5e | 831 | else |
1afaba1e | 832 | new_type = __OVL_PATH_UPPER | __OVL_PATH_PURE; |
e9be9d5e MS |
833 | } |
834 | ||
835 | err = ovl_want_write(old); | |
836 | if (err) | |
837 | goto out; | |
838 | ||
839 | err = ovl_copy_up(old); | |
840 | if (err) | |
841 | goto out_drop_write; | |
842 | ||
843 | err = ovl_copy_up(new->d_parent); | |
844 | if (err) | |
845 | goto out_drop_write; | |
846 | if (!overwrite) { | |
847 | err = ovl_copy_up(new); | |
848 | if (err) | |
849 | goto out_drop_write; | |
850 | } | |
851 | ||
1afaba1e MS |
852 | old_opaque = !OVL_TYPE_PURE_UPPER(old_type); |
853 | new_opaque = !OVL_TYPE_PURE_UPPER(new_type); | |
e9be9d5e | 854 | |
1175b6b8 | 855 | old_cred = ovl_override_creds(old->d_sb); |
e9be9d5e | 856 | |
1afaba1e | 857 | if (overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) { |
a105d685 | 858 | opaquedir = ovl_check_empty_and_clear(new); |
e9be9d5e MS |
859 | err = PTR_ERR(opaquedir); |
860 | if (IS_ERR(opaquedir)) { | |
861 | opaquedir = NULL; | |
862 | goto out_revert_creds; | |
863 | } | |
864 | } | |
865 | ||
866 | if (overwrite) { | |
867 | if (old_opaque) { | |
868 | if (new->d_inode || !new_opaque) { | |
869 | /* Whiteout source */ | |
870 | flags |= RENAME_WHITEOUT; | |
871 | } else { | |
872 | /* Switch whiteouts */ | |
873 | flags |= RENAME_EXCHANGE; | |
874 | } | |
875 | } else if (is_dir && !new->d_inode && new_opaque) { | |
876 | flags |= RENAME_EXCHANGE; | |
877 | cleanup_whiteout = true; | |
878 | } | |
879 | } | |
880 | ||
881 | old_upperdir = ovl_dentry_upper(old->d_parent); | |
882 | new_upperdir = ovl_dentry_upper(new->d_parent); | |
883 | ||
884 | trap = lock_rename(new_upperdir, old_upperdir); | |
885 | ||
11f37104 MS |
886 | |
887 | olddentry = lookup_one_len(old->d_name.name, old_upperdir, | |
888 | old->d_name.len); | |
889 | err = PTR_ERR(olddentry); | |
890 | if (IS_ERR(olddentry)) | |
891 | goto out_unlock; | |
892 | ||
893 | err = -ESTALE; | |
894 | if (olddentry != ovl_dentry_upper(old)) | |
895 | goto out_dput_old; | |
896 | ||
897 | newdentry = lookup_one_len(new->d_name.name, new_upperdir, | |
898 | new->d_name.len); | |
899 | err = PTR_ERR(newdentry); | |
900 | if (IS_ERR(newdentry)) | |
901 | goto out_dput_old; | |
902 | ||
903 | err = -ESTALE; | |
904 | if (ovl_dentry_upper(new)) { | |
e9be9d5e | 905 | if (opaquedir) { |
11f37104 MS |
906 | if (newdentry != opaquedir) |
907 | goto out_dput; | |
e9be9d5e | 908 | } else { |
11f37104 MS |
909 | if (newdentry != ovl_dentry_upper(new)) |
910 | goto out_dput; | |
e9be9d5e MS |
911 | } |
912 | } else { | |
11f37104 MS |
913 | if (!d_is_negative(newdentry) && |
914 | (!new_opaque || !ovl_is_whiteout(newdentry))) | |
915 | goto out_dput; | |
e9be9d5e MS |
916 | } |
917 | ||
e9be9d5e MS |
918 | if (olddentry == trap) |
919 | goto out_dput; | |
920 | if (newdentry == trap) | |
921 | goto out_dput; | |
922 | ||
923 | if (is_dir && !old_opaque && new_opaque) { | |
924 | err = ovl_set_opaque(olddentry); | |
925 | if (err) | |
926 | goto out_dput; | |
927 | } | |
928 | if (!overwrite && new_is_dir && old_opaque && !new_opaque) { | |
929 | err = ovl_set_opaque(newdentry); | |
930 | if (err) | |
931 | goto out_dput; | |
932 | } | |
933 | ||
934 | if (old_opaque || new_opaque) { | |
935 | err = ovl_do_rename(old_upperdir->d_inode, olddentry, | |
936 | new_upperdir->d_inode, newdentry, | |
937 | flags); | |
938 | } else { | |
939 | /* No debug for the plain case */ | |
940 | BUG_ON(flags & ~RENAME_EXCHANGE); | |
941 | err = vfs_rename(old_upperdir->d_inode, olddentry, | |
942 | new_upperdir->d_inode, newdentry, | |
943 | NULL, flags); | |
944 | } | |
945 | ||
946 | if (err) { | |
947 | if (is_dir && !old_opaque && new_opaque) | |
948 | ovl_remove_opaque(olddentry); | |
949 | if (!overwrite && new_is_dir && old_opaque && !new_opaque) | |
950 | ovl_remove_opaque(newdentry); | |
951 | goto out_dput; | |
952 | } | |
953 | ||
954 | if (is_dir && old_opaque && !new_opaque) | |
955 | ovl_remove_opaque(olddentry); | |
956 | if (!overwrite && new_is_dir && !old_opaque && new_opaque) | |
957 | ovl_remove_opaque(newdentry); | |
958 | ||
45d11738 KK |
959 | /* |
960 | * Old dentry now lives in different location. Dentries in | |
961 | * lowerstack are stale. We cannot drop them here because | |
962 | * access to them is lockless. This could be only pure upper | |
963 | * or opaque directory - numlower is zero. Or upper non-dir | |
964 | * entry - its pureness is tracked by flag opaque. | |
965 | */ | |
e9be9d5e MS |
966 | if (old_opaque != new_opaque) { |
967 | ovl_dentry_set_opaque(old, new_opaque); | |
968 | if (!overwrite) | |
969 | ovl_dentry_set_opaque(new, old_opaque); | |
970 | } | |
971 | ||
972 | if (cleanup_whiteout) | |
973 | ovl_cleanup(old_upperdir->d_inode, newdentry); | |
974 | ||
975 | ovl_dentry_version_inc(old->d_parent); | |
976 | ovl_dentry_version_inc(new->d_parent); | |
977 | ||
978 | out_dput: | |
979 | dput(newdentry); | |
11f37104 MS |
980 | out_dput_old: |
981 | dput(olddentry); | |
e9be9d5e MS |
982 | out_unlock: |
983 | unlock_rename(new_upperdir, old_upperdir); | |
984 | out_revert_creds: | |
1175b6b8 | 985 | revert_creds(old_cred); |
e9be9d5e MS |
986 | out_drop_write: |
987 | ovl_drop_write(old); | |
988 | out: | |
989 | dput(opaquedir); | |
990 | return err; | |
991 | } | |
992 | ||
993 | const struct inode_operations ovl_dir_inode_operations = { | |
994 | .lookup = ovl_lookup, | |
995 | .mkdir = ovl_mkdir, | |
996 | .symlink = ovl_symlink, | |
997 | .unlink = ovl_unlink, | |
998 | .rmdir = ovl_rmdir, | |
999 | .rename2 = ovl_rename2, | |
1000 | .link = ovl_link, | |
1001 | .setattr = ovl_setattr, | |
1002 | .create = ovl_create, | |
1003 | .mknod = ovl_mknod, | |
1004 | .permission = ovl_permission, | |
1005 | .getattr = ovl_dir_getattr, | |
d837a49b | 1006 | .setxattr = generic_setxattr, |
0eb45fc3 | 1007 | .getxattr = generic_getxattr, |
e9be9d5e | 1008 | .listxattr = ovl_listxattr, |
0e585ccc | 1009 | .removexattr = generic_removexattr, |
39a25b2b | 1010 | .get_acl = ovl_get_acl, |
d719e8f2 | 1011 | .update_time = ovl_update_time, |
e9be9d5e | 1012 | }; |