1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * |
4 | * Copyright (C) 2011 Novell Inc. |
5 | */ |
6 | |
7 | #include <linux/fs.h> |
8 | #include <linux/namei.h> |
9 | #include <linux/xattr.h> |
10 | #include <linux/security.h> |
11 | #include <linux/cred.h> |
12 | #include <linux/module.h> |
13 | #include <linux/posix_acl.h> |
14 | #include <linux/posix_acl_xattr.h> |
15 | #include <linux/atomic.h> |
16 | #include <linux/ratelimit.h> |
17 | #include "overlayfs.h" |
18 | |
19 | static unsigned short ovl_redirect_max = 256; |
20 | module_param_named(redirect_max, ovl_redirect_max, ushort, 0644); |
21 | MODULE_PARM_DESC(redirect_max, |
22 | "Maximum length of absolute redirect xattr value" ); |
23 | |
24 | static int ovl_set_redirect(struct dentry *dentry, bool samedir); |
25 | |
26 | int ovl_cleanup(struct ovl_fs *ofs, struct inode *wdir, struct dentry *wdentry) |
27 | { |
28 | int err; |
29 | |
30 | dget(dentry: wdentry); |
31 | if (d_is_dir(dentry: wdentry)) |
32 | err = ovl_do_rmdir(ofs, dir: wdir, dentry: wdentry); |
33 | else |
34 | err = ovl_do_unlink(ofs, dir: wdir, dentry: wdentry); |
35 | dput(wdentry); |
36 | |
37 | if (err) { |
38 | pr_err("cleanup of '%pd2' failed (%i)\n" , |
39 | wdentry, err); |
40 | } |
41 | |
42 | return err; |
43 | } |
44 | |
45 | struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir) |
46 | { |
47 | struct dentry *temp; |
48 | char name[20]; |
49 | static atomic_t temp_id = ATOMIC_INIT(0); |
50 | |
51 | /* counter is allowed to wrap, since temp dentries are ephemeral */ |
52 | snprintf(buf: name, size: sizeof(name), fmt: "#%x" , atomic_inc_return(v: &temp_id)); |
53 | |
54 | temp = ovl_lookup_upper(ofs, name, base: workdir, strlen(name)); |
55 | if (!IS_ERR(ptr: temp) && temp->d_inode) { |
56 | pr_err("workdir/%s already exists\n" , name); |
57 | dput(temp); |
58 | temp = ERR_PTR(error: -EIO); |
59 | } |
60 | |
61 | return temp; |
62 | } |
63 | |
64 | /* caller holds i_mutex on workdir */ |
65 | static struct dentry *ovl_whiteout(struct ovl_fs *ofs) |
66 | { |
67 | int err; |
68 | struct dentry *whiteout; |
69 | struct dentry *workdir = ofs->workdir; |
70 | struct inode *wdir = workdir->d_inode; |
71 | |
72 | if (!ofs->whiteout) { |
73 | whiteout = ovl_lookup_temp(ofs, workdir); |
74 | if (IS_ERR(ptr: whiteout)) |
75 | goto out; |
76 | |
77 | err = ovl_do_whiteout(ofs, dir: wdir, dentry: whiteout); |
78 | if (err) { |
79 | dput(whiteout); |
80 | whiteout = ERR_PTR(error: err); |
81 | goto out; |
82 | } |
83 | ofs->whiteout = whiteout; |
84 | } |
85 | |
86 | if (!ofs->no_shared_whiteout) { |
87 | whiteout = ovl_lookup_temp(ofs, workdir); |
88 | if (IS_ERR(ptr: whiteout)) |
89 | goto out; |
90 | |
91 | err = ovl_do_link(ofs, old_dentry: ofs->whiteout, dir: wdir, new_dentry: whiteout); |
92 | if (!err) |
93 | goto out; |
94 | |
95 | if (err != -EMLINK) { |
96 | pr_warn("Failed to link whiteout - disabling whiteout inode sharing(nlink=%u, err=%i)\n" , |
97 | ofs->whiteout->d_inode->i_nlink, err); |
98 | ofs->no_shared_whiteout = true; |
99 | } |
100 | dput(whiteout); |
101 | } |
102 | whiteout = ofs->whiteout; |
103 | ofs->whiteout = NULL; |
104 | out: |
105 | return whiteout; |
106 | } |
107 | |
108 | /* Caller must hold i_mutex on both workdir and dir */ |
109 | int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, |
110 | struct dentry *dentry) |
111 | { |
112 | struct inode *wdir = ofs->workdir->d_inode; |
113 | struct dentry *whiteout; |
114 | int err; |
115 | int flags = 0; |
116 | |
117 | whiteout = ovl_whiteout(ofs); |
118 | err = PTR_ERR(ptr: whiteout); |
119 | if (IS_ERR(ptr: whiteout)) |
120 | return err; |
121 | |
122 | if (d_is_dir(dentry)) |
123 | flags = RENAME_EXCHANGE; |
124 | |
125 | err = ovl_do_rename(ofs, olddir: wdir, olddentry: whiteout, newdir: dir, newdentry: dentry, flags); |
126 | if (err) |
127 | goto kill_whiteout; |
128 | if (flags) |
129 | ovl_cleanup(ofs, wdir, wdentry: dentry); |
130 | |
131 | out: |
132 | dput(whiteout); |
133 | return err; |
134 | |
135 | kill_whiteout: |
136 | ovl_cleanup(ofs, wdir, wdentry: whiteout); |
137 | goto out; |
138 | } |
139 | |
140 | int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, |
141 | struct dentry **newdentry, umode_t mode) |
142 | { |
143 | int err; |
144 | struct dentry *d, *dentry = *newdentry; |
145 | |
146 | err = ovl_do_mkdir(ofs, dir, dentry, mode); |
147 | if (err) |
148 | return err; |
149 | |
150 | if (likely(!d_unhashed(dentry))) |
151 | return 0; |
152 | |
153 | /* |
154 | * vfs_mkdir() may succeed and leave the dentry passed |
155 | * to it unhashed and negative. If that happens, try to |
156 | * lookup a new hashed and positive dentry. |
157 | */ |
158 | d = ovl_lookup_upper(ofs, name: dentry->d_name.name, base: dentry->d_parent, |
159 | len: dentry->d_name.len); |
160 | if (IS_ERR(ptr: d)) { |
161 | pr_warn("failed lookup after mkdir (%pd2, err=%i).\n" , |
162 | dentry, err); |
163 | return PTR_ERR(ptr: d); |
164 | } |
165 | dput(dentry); |
166 | *newdentry = d; |
167 | |
168 | return 0; |
169 | } |
170 | |
171 | struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir, |
172 | struct dentry *newdentry, struct ovl_cattr *attr) |
173 | { |
174 | int err; |
175 | |
176 | if (IS_ERR(ptr: newdentry)) |
177 | return newdentry; |
178 | |
179 | err = -ESTALE; |
180 | if (newdentry->d_inode) |
181 | goto out; |
182 | |
183 | if (attr->hardlink) { |
184 | err = ovl_do_link(ofs, old_dentry: attr->hardlink, dir, new_dentry: newdentry); |
185 | } else { |
186 | switch (attr->mode & S_IFMT) { |
187 | case S_IFREG: |
188 | err = ovl_do_create(ofs, dir, dentry: newdentry, mode: attr->mode); |
189 | break; |
190 | |
191 | case S_IFDIR: |
192 | /* mkdir is special... */ |
193 | err = ovl_mkdir_real(ofs, dir, newdentry: &newdentry, mode: attr->mode); |
194 | break; |
195 | |
196 | case S_IFCHR: |
197 | case S_IFBLK: |
198 | case S_IFIFO: |
199 | case S_IFSOCK: |
200 | err = ovl_do_mknod(ofs, dir, dentry: newdentry, mode: attr->mode, |
201 | dev: attr->rdev); |
202 | break; |
203 | |
204 | case S_IFLNK: |
205 | err = ovl_do_symlink(ofs, dir, dentry: newdentry, oldname: attr->link); |
206 | break; |
207 | |
208 | default: |
209 | err = -EPERM; |
210 | } |
211 | } |
212 | if (!err && WARN_ON(!newdentry->d_inode)) { |
213 | /* |
214 | * Not quite sure if non-instantiated dentry is legal or not. |
215 | * VFS doesn't seem to care so check and warn here. |
216 | */ |
217 | err = -EIO; |
218 | } |
219 | out: |
220 | if (err) { |
221 | dput(newdentry); |
222 | return ERR_PTR(error: err); |
223 | } |
224 | return newdentry; |
225 | } |
226 | |
227 | struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, |
228 | struct ovl_cattr *attr) |
229 | { |
230 | return ovl_create_real(ofs, dir: d_inode(dentry: workdir), |
231 | newdentry: ovl_lookup_temp(ofs, workdir), attr); |
232 | } |
233 | |
234 | static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper, |
235 | int xerr) |
236 | { |
237 | struct ovl_fs *ofs = OVL_FS(sb: dentry->d_sb); |
238 | int err; |
239 | |
240 | err = ovl_check_setxattr(ofs, upperdentry: upper, ox: OVL_XATTR_OPAQUE, value: "y" , size: 1, xerr); |
241 | if (!err) |
242 | ovl_dentry_set_opaque(dentry); |
243 | |
244 | return err; |
245 | } |
246 | |
247 | static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) |
248 | { |
249 | /* |
250 | * Fail with -EIO when trying to create opaque dir and upper doesn't |
251 | * support xattrs. ovl_rename() calls ovl_set_opaque_xerr(-EXDEV) to |
252 | * return a specific error for noxattr case. |
253 | */ |
254 | return ovl_set_opaque_xerr(dentry, upper: upperdentry, xerr: -EIO); |
255 | } |
256 | |
257 | /* |
258 | * Common operations required to be done after creation of file on upper. |
259 | * If @hardlink is false, then @inode is a pre-allocated inode, we may or |
260 | * may not use to instantiate the new dentry. |
261 | */ |
262 | static int ovl_instantiate(struct dentry *dentry, struct inode *inode, |
263 | struct dentry *newdentry, bool hardlink) |
264 | { |
265 | struct ovl_inode_params oip = { |
266 | .upperdentry = newdentry, |
267 | .newinode = inode, |
268 | }; |
269 | |
270 | ovl_dir_modified(dentry: dentry->d_parent, impurity: false); |
271 | ovl_dentry_set_upper_alias(dentry); |
272 | ovl_dentry_init_reval(dentry, upperdentry: newdentry, NULL); |
273 | |
274 | if (!hardlink) { |
275 | /* |
276 | * ovl_obtain_alias() can be called after ovl_create_real() |
277 | * and before we get here, so we may get an inode from cache |
278 | * with the same real upperdentry that is not the inode we |
279 | * pre-allocated. In this case we will use the cached inode |
280 | * to instantiate the new dentry. |
281 | * |
282 | * XXX: if we ever use ovl_obtain_alias() to decode directory |
283 | * file handles, need to use ovl_get_inode_locked() and |
284 | * d_instantiate_new() here to prevent from creating two |
285 | * hashed directory inode aliases. |
286 | */ |
287 | inode = ovl_get_inode(sb: dentry->d_sb, oip: &oip); |
288 | if (IS_ERR(ptr: inode)) |
289 | return PTR_ERR(ptr: inode); |
290 | if (inode == oip.newinode) |
291 | ovl_set_flag(flag: OVL_UPPERDATA, inode); |
292 | } else { |
293 | WARN_ON(ovl_inode_real(inode) != d_inode(newdentry)); |
294 | dput(newdentry); |
295 | inc_nlink(inode); |
296 | } |
297 | |
298 | d_instantiate(dentry, inode); |
299 | if (inode != oip.newinode) { |
300 | pr_warn_ratelimited("newly created inode found in cache (%pd2)\n" , |
301 | dentry); |
302 | } |
303 | |
304 | /* Force lookup of new upper hardlink to find its lower */ |
305 | if (hardlink) |
306 | d_drop(dentry); |
307 | |
308 | return 0; |
309 | } |
310 | |
311 | static bool ovl_type_merge(struct dentry *dentry) |
312 | { |
313 | return OVL_TYPE_MERGE(ovl_path_type(dentry)); |
314 | } |
315 | |
316 | static bool ovl_type_origin(struct dentry *dentry) |
317 | { |
318 | return OVL_TYPE_ORIGIN(ovl_path_type(dentry)); |
319 | } |
320 | |
321 | static int ovl_create_upper(struct dentry *dentry, struct inode *inode, |
322 | struct ovl_cattr *attr) |
323 | { |
324 | struct ovl_fs *ofs = OVL_FS(sb: dentry->d_sb); |
325 | struct dentry *upperdir = ovl_dentry_upper(dentry: dentry->d_parent); |
326 | struct inode *udir = upperdir->d_inode; |
327 | struct dentry *newdentry; |
328 | int err; |
329 | |
330 | if (!attr->hardlink && !IS_POSIXACL(udir)) |
331 | attr->mode &= ~current_umask(); |
332 | |
333 | inode_lock_nested(inode: udir, subclass: I_MUTEX_PARENT); |
334 | newdentry = ovl_create_real(ofs, dir: udir, |
335 | newdentry: ovl_lookup_upper(ofs, name: dentry->d_name.name, |
336 | base: upperdir, len: dentry->d_name.len), |
337 | attr); |
338 | err = PTR_ERR(ptr: newdentry); |
339 | if (IS_ERR(ptr: newdentry)) |
340 | goto out_unlock; |
341 | |
342 | if (ovl_type_merge(dentry: dentry->d_parent) && d_is_dir(dentry: newdentry) && |
343 | !ovl_allow_offline_changes(ofs)) { |
344 | /* Setting opaque here is just an optimization, allow to fail */ |
345 | ovl_set_opaque(dentry, upperdentry: newdentry); |
346 | } |
347 | |
348 | err = ovl_instantiate(dentry, inode, newdentry, hardlink: !!attr->hardlink); |
349 | if (err) |
350 | goto out_cleanup; |
351 | out_unlock: |
352 | inode_unlock(inode: udir); |
353 | return err; |
354 | |
355 | out_cleanup: |
356 | ovl_cleanup(ofs, wdir: udir, wdentry: newdentry); |
357 | dput(newdentry); |
358 | goto out_unlock; |
359 | } |
360 | |
361 | static struct dentry *ovl_clear_empty(struct dentry *dentry, |
362 | struct list_head *list) |
363 | { |
364 | struct ovl_fs *ofs = OVL_FS(sb: dentry->d_sb); |
365 | struct dentry *workdir = ovl_workdir(dentry); |
366 | struct inode *wdir = workdir->d_inode; |
367 | struct dentry *upperdir = ovl_dentry_upper(dentry: dentry->d_parent); |
368 | struct inode *udir = upperdir->d_inode; |
369 | struct path upperpath; |
370 | struct dentry *upper; |
371 | struct dentry *opaquedir; |
372 | struct kstat stat; |
373 | int err; |
374 | |
375 | if (WARN_ON(!workdir)) |
376 | return ERR_PTR(error: -EROFS); |
377 | |
378 | err = ovl_lock_rename_workdir(workdir, upperdir); |
379 | if (err) |
380 | goto out; |
381 | |
382 | ovl_path_upper(dentry, path: &upperpath); |
383 | err = vfs_getattr(&upperpath, &stat, |
384 | STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); |
385 | if (err) |
386 | goto out_unlock; |
387 | |
388 | err = -ESTALE; |
389 | if (!S_ISDIR(stat.mode)) |
390 | goto out_unlock; |
391 | upper = upperpath.dentry; |
392 | if (upper->d_parent->d_inode != udir) |
393 | goto out_unlock; |
394 | |
395 | opaquedir = ovl_create_temp(ofs, workdir, OVL_CATTR(stat.mode)); |
396 | err = PTR_ERR(ptr: opaquedir); |
397 | if (IS_ERR(ptr: opaquedir)) |
398 | goto out_unlock; |
399 | |
400 | err = ovl_copy_xattr(sb: dentry->d_sb, path: &upperpath, new: opaquedir); |
401 | if (err) |
402 | goto out_cleanup; |
403 | |
404 | err = ovl_set_opaque(dentry, upperdentry: opaquedir); |
405 | if (err) |
406 | goto out_cleanup; |
407 | |
408 | inode_lock(inode: opaquedir->d_inode); |
409 | err = ovl_set_attr(ofs, upper: opaquedir, stat: &stat); |
410 | inode_unlock(inode: opaquedir->d_inode); |
411 | if (err) |
412 | goto out_cleanup; |
413 | |
414 | err = ovl_do_rename(ofs, olddir: wdir, olddentry: opaquedir, newdir: udir, newdentry: upper, RENAME_EXCHANGE); |
415 | if (err) |
416 | goto out_cleanup; |
417 | |
418 | ovl_cleanup_whiteouts(ofs, upper, list); |
419 | ovl_cleanup(ofs, wdir, wdentry: upper); |
420 | unlock_rename(workdir, upperdir); |
421 | |
422 | /* dentry's upper doesn't match now, get rid of it */ |
423 | d_drop(dentry); |
424 | |
425 | return opaquedir; |
426 | |
427 | out_cleanup: |
428 | ovl_cleanup(ofs, wdir, wdentry: opaquedir); |
429 | dput(opaquedir); |
430 | out_unlock: |
431 | unlock_rename(workdir, upperdir); |
432 | out: |
433 | return ERR_PTR(error: err); |
434 | } |
435 | |
436 | static int ovl_set_upper_acl(struct ovl_fs *ofs, struct dentry *upperdentry, |
437 | const char *acl_name, struct posix_acl *acl) |
438 | { |
439 | if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl) |
440 | return 0; |
441 | |
442 | return ovl_do_set_acl(ofs, dentry: upperdentry, acl_name, acl); |
443 | } |
444 | |
445 | static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, |
446 | struct ovl_cattr *cattr) |
447 | { |
448 | struct ovl_fs *ofs = OVL_FS(sb: dentry->d_sb); |
449 | struct dentry *workdir = ovl_workdir(dentry); |
450 | struct inode *wdir = workdir->d_inode; |
451 | struct dentry *upperdir = ovl_dentry_upper(dentry: dentry->d_parent); |
452 | struct inode *udir = upperdir->d_inode; |
453 | struct dentry *upper; |
454 | struct dentry *newdentry; |
455 | int err; |
456 | struct posix_acl *acl, *default_acl; |
457 | bool hardlink = !!cattr->hardlink; |
458 | |
459 | if (WARN_ON(!workdir)) |
460 | return -EROFS; |
461 | |
462 | if (!hardlink) { |
463 | err = posix_acl_create(dentry->d_parent->d_inode, |
464 | &cattr->mode, &default_acl, &acl); |
465 | if (err) |
466 | return err; |
467 | } |
468 | |
469 | err = ovl_lock_rename_workdir(workdir, upperdir); |
470 | if (err) |
471 | goto out; |
472 | |
473 | upper = ovl_lookup_upper(ofs, name: dentry->d_name.name, base: upperdir, |
474 | len: dentry->d_name.len); |
475 | err = PTR_ERR(ptr: upper); |
476 | if (IS_ERR(ptr: upper)) |
477 | goto out_unlock; |
478 | |
479 | err = -ESTALE; |
480 | if (d_is_negative(dentry: upper) || !ovl_upper_is_whiteout(ofs, upperdentry: upper)) |
481 | goto out_dput; |
482 | |
483 | newdentry = ovl_create_temp(ofs, workdir, attr: cattr); |
484 | err = PTR_ERR(ptr: newdentry); |
485 | if (IS_ERR(ptr: newdentry)) |
486 | goto out_dput; |
487 | |
488 | /* |
489 | * mode could have been mutilated due to umask (e.g. sgid directory) |
490 | */ |
491 | if (!hardlink && |
492 | !S_ISLNK(cattr->mode) && |
493 | newdentry->d_inode->i_mode != cattr->mode) { |
494 | struct iattr attr = { |
495 | .ia_valid = ATTR_MODE, |
496 | .ia_mode = cattr->mode, |
497 | }; |
498 | inode_lock(inode: newdentry->d_inode); |
499 | err = ovl_do_notify_change(ofs, upperdentry: newdentry, attr: &attr); |
500 | inode_unlock(inode: newdentry->d_inode); |
501 | if (err) |
502 | goto out_cleanup; |
503 | } |
504 | if (!hardlink) { |
505 | err = ovl_set_upper_acl(ofs, upperdentry: newdentry, |
506 | XATTR_NAME_POSIX_ACL_ACCESS, acl); |
507 | if (err) |
508 | goto out_cleanup; |
509 | |
510 | err = ovl_set_upper_acl(ofs, upperdentry: newdentry, |
511 | XATTR_NAME_POSIX_ACL_DEFAULT, acl: default_acl); |
512 | if (err) |
513 | goto out_cleanup; |
514 | } |
515 | |
516 | if (!hardlink && S_ISDIR(cattr->mode)) { |
517 | err = ovl_set_opaque(dentry, upperdentry: newdentry); |
518 | if (err) |
519 | goto out_cleanup; |
520 | |
521 | err = ovl_do_rename(ofs, olddir: wdir, olddentry: newdentry, newdir: udir, newdentry: upper, |
522 | RENAME_EXCHANGE); |
523 | if (err) |
524 | goto out_cleanup; |
525 | |
526 | ovl_cleanup(ofs, wdir, wdentry: upper); |
527 | } else { |
528 | err = ovl_do_rename(ofs, olddir: wdir, olddentry: newdentry, newdir: udir, newdentry: upper, flags: 0); |
529 | if (err) |
530 | goto out_cleanup; |
531 | } |
532 | err = ovl_instantiate(dentry, inode, newdentry, hardlink); |
533 | if (err) { |
534 | ovl_cleanup(ofs, wdir: udir, wdentry: newdentry); |
535 | dput(newdentry); |
536 | } |
537 | out_dput: |
538 | dput(upper); |
539 | out_unlock: |
540 | unlock_rename(workdir, upperdir); |
541 | out: |
542 | if (!hardlink) { |
543 | posix_acl_release(acl); |
544 | posix_acl_release(acl: default_acl); |
545 | } |
546 | return err; |
547 | |
548 | out_cleanup: |
549 | ovl_cleanup(ofs, wdir, wdentry: newdentry); |
550 | dput(newdentry); |
551 | goto out_dput; |
552 | } |
553 | |
554 | static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, |
555 | struct ovl_cattr *attr, bool origin) |
556 | { |
557 | int err; |
558 | const struct cred *old_cred; |
559 | struct cred *override_cred; |
560 | struct dentry *parent = dentry->d_parent; |
561 | |
562 | old_cred = ovl_override_creds(sb: dentry->d_sb); |
563 | |
564 | /* |
565 | * When linking a file with copy up origin into a new parent, mark the |
566 | * new parent dir "impure". |
567 | */ |
568 | if (origin) { |
569 | err = ovl_set_impure(dentry: parent, upperdentry: ovl_dentry_upper(dentry: parent)); |
570 | if (err) |
571 | goto out_revert_creds; |
572 | } |
573 | |
574 | if (!attr->hardlink) { |
575 | err = -ENOMEM; |
576 | override_cred = prepare_creds(); |
577 | if (!override_cred) |
578 | goto out_revert_creds; |
579 | /* |
580 | * In the creation cases(create, mkdir, mknod, symlink), |
581 | * ovl should transfer current's fs{u,g}id to underlying |
582 | * fs. Because underlying fs want to initialize its new |
583 | * inode owner using current's fs{u,g}id. And in this |
584 | * case, the @inode is a new inode that is initialized |
585 | * in inode_init_owner() to current's fs{u,g}id. So use |
586 | * the inode's i_{u,g}id to override the cred's fs{u,g}id. |
587 | * |
588 | * But in the other hardlink case, ovl_link() does not |
589 | * create a new inode, so just use the ovl mounter's |
590 | * fs{u,g}id. |
591 | */ |
592 | override_cred->fsuid = inode->i_uid; |
593 | override_cred->fsgid = inode->i_gid; |
594 | err = security_dentry_create_files_as(dentry, |
595 | mode: attr->mode, name: &dentry->d_name, old: old_cred, |
596 | new: override_cred); |
597 | if (err) { |
598 | put_cred(cred: override_cred); |
599 | goto out_revert_creds; |
600 | } |
601 | put_cred(cred: override_creds(override_cred)); |
602 | put_cred(cred: override_cred); |
603 | } |
604 | |
605 | if (!ovl_dentry_is_whiteout(dentry)) |
606 | err = ovl_create_upper(dentry, inode, attr); |
607 | else |
608 | err = ovl_create_over_whiteout(dentry, inode, cattr: attr); |
609 | |
610 | out_revert_creds: |
611 | revert_creds(old_cred); |
612 | return err; |
613 | } |
614 | |
615 | static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, |
616 | const char *link) |
617 | { |
618 | int err; |
619 | struct inode *inode; |
620 | struct ovl_cattr attr = { |
621 | .rdev = rdev, |
622 | .link = link, |
623 | }; |
624 | |
625 | err = ovl_copy_up(dentry: dentry->d_parent); |
626 | if (err) |
627 | return err; |
628 | |
629 | err = ovl_want_write(dentry); |
630 | if (err) |
631 | goto out; |
632 | |
633 | /* Preallocate inode to be used by ovl_get_inode() */ |
634 | err = -ENOMEM; |
635 | inode = ovl_new_inode(sb: dentry->d_sb, mode, rdev); |
636 | if (!inode) |
637 | goto out_drop_write; |
638 | |
639 | spin_lock(lock: &inode->i_lock); |
640 | inode->i_state |= I_CREATING; |
641 | spin_unlock(lock: &inode->i_lock); |
642 | |
643 | inode_init_owner(idmap: &nop_mnt_idmap, inode, dir: dentry->d_parent->d_inode, mode); |
644 | attr.mode = inode->i_mode; |
645 | |
646 | err = ovl_create_or_link(dentry, inode, attr: &attr, origin: false); |
647 | /* Did we end up using the preallocated inode? */ |
648 | if (inode != d_inode(dentry)) |
649 | iput(inode); |
650 | |
651 | out_drop_write: |
652 | ovl_drop_write(dentry); |
653 | out: |
654 | return err; |
655 | } |
656 | |
657 | static int ovl_create(struct mnt_idmap *idmap, struct inode *dir, |
658 | struct dentry *dentry, umode_t mode, bool excl) |
659 | { |
660 | return ovl_create_object(dentry, mode: (mode & 07777) | S_IFREG, rdev: 0, NULL); |
661 | } |
662 | |
663 | static int ovl_mkdir(struct mnt_idmap *idmap, struct inode *dir, |
664 | struct dentry *dentry, umode_t mode) |
665 | { |
666 | return ovl_create_object(dentry, mode: (mode & 07777) | S_IFDIR, rdev: 0, NULL); |
667 | } |
668 | |
669 | static int ovl_mknod(struct mnt_idmap *idmap, struct inode *dir, |
670 | struct dentry *dentry, umode_t mode, dev_t rdev) |
671 | { |
672 | /* Don't allow creation of "whiteout" on overlay */ |
673 | if (S_ISCHR(mode) && rdev == WHITEOUT_DEV) |
674 | return -EPERM; |
675 | |
676 | return ovl_create_object(dentry, mode, rdev, NULL); |
677 | } |
678 | |
679 | static int ovl_symlink(struct mnt_idmap *idmap, struct inode *dir, |
680 | struct dentry *dentry, const char *link) |
681 | { |
682 | return ovl_create_object(dentry, S_IFLNK, rdev: 0, link); |
683 | } |
684 | |
685 | static int ovl_set_link_redirect(struct dentry *dentry) |
686 | { |
687 | const struct cred *old_cred; |
688 | int err; |
689 | |
690 | old_cred = ovl_override_creds(sb: dentry->d_sb); |
691 | err = ovl_set_redirect(dentry, samedir: false); |
692 | revert_creds(old_cred); |
693 | |
694 | return err; |
695 | } |
696 | |
697 | static int ovl_link(struct dentry *old, struct inode *newdir, |
698 | struct dentry *new) |
699 | { |
700 | int err; |
701 | struct inode *inode; |
702 | |
703 | err = ovl_copy_up(dentry: old); |
704 | if (err) |
705 | goto out; |
706 | |
707 | err = ovl_copy_up(dentry: new->d_parent); |
708 | if (err) |
709 | goto out; |
710 | |
711 | err = ovl_nlink_start(dentry: old); |
712 | if (err) |
713 | goto out; |
714 | |
715 | if (ovl_is_metacopy_dentry(dentry: old)) { |
716 | err = ovl_set_link_redirect(dentry: old); |
717 | if (err) |
718 | goto out_nlink_end; |
719 | } |
720 | |
721 | inode = d_inode(dentry: old); |
722 | ihold(inode); |
723 | |
724 | err = ovl_create_or_link(dentry: new, inode, |
725 | attr: &(struct ovl_cattr) {.hardlink = ovl_dentry_upper(dentry: old)}, |
726 | origin: ovl_type_origin(dentry: old)); |
727 | if (err) |
728 | iput(inode); |
729 | |
730 | out_nlink_end: |
731 | ovl_nlink_end(dentry: old); |
732 | out: |
733 | return err; |
734 | } |
735 | |
736 | static bool ovl_matches_upper(struct dentry *dentry, struct dentry *upper) |
737 | { |
738 | return d_inode(dentry: ovl_dentry_upper(dentry)) == d_inode(dentry: upper); |
739 | } |
740 | |
741 | static int ovl_remove_and_whiteout(struct dentry *dentry, |
742 | struct list_head *list) |
743 | { |
744 | struct ovl_fs *ofs = OVL_FS(sb: dentry->d_sb); |
745 | struct dentry *workdir = ovl_workdir(dentry); |
746 | struct dentry *upperdir = ovl_dentry_upper(dentry: dentry->d_parent); |
747 | struct dentry *upper; |
748 | struct dentry *opaquedir = NULL; |
749 | int err; |
750 | |
751 | if (WARN_ON(!workdir)) |
752 | return -EROFS; |
753 | |
754 | if (!list_empty(head: list)) { |
755 | opaquedir = ovl_clear_empty(dentry, list); |
756 | err = PTR_ERR(ptr: opaquedir); |
757 | if (IS_ERR(ptr: opaquedir)) |
758 | goto out; |
759 | } |
760 | |
761 | err = ovl_lock_rename_workdir(workdir, upperdir); |
762 | if (err) |
763 | goto out_dput; |
764 | |
765 | upper = ovl_lookup_upper(ofs, name: dentry->d_name.name, base: upperdir, |
766 | len: dentry->d_name.len); |
767 | err = PTR_ERR(ptr: upper); |
768 | if (IS_ERR(ptr: upper)) |
769 | goto out_unlock; |
770 | |
771 | err = -ESTALE; |
772 | if ((opaquedir && upper != opaquedir) || |
773 | (!opaquedir && ovl_dentry_upper(dentry) && |
774 | !ovl_matches_upper(dentry, upper))) { |
775 | goto out_dput_upper; |
776 | } |
777 | |
778 | err = ovl_cleanup_and_whiteout(ofs, dir: d_inode(dentry: upperdir), dentry: upper); |
779 | if (err) |
780 | goto out_d_drop; |
781 | |
782 | ovl_dir_modified(dentry: dentry->d_parent, impurity: true); |
783 | out_d_drop: |
784 | d_drop(dentry); |
785 | out_dput_upper: |
786 | dput(upper); |
787 | out_unlock: |
788 | unlock_rename(workdir, upperdir); |
789 | out_dput: |
790 | dput(opaquedir); |
791 | out: |
792 | return err; |
793 | } |
794 | |
795 | static int ovl_remove_upper(struct dentry *dentry, bool is_dir, |
796 | struct list_head *list) |
797 | { |
798 | struct ovl_fs *ofs = OVL_FS(sb: dentry->d_sb); |
799 | struct dentry *upperdir = ovl_dentry_upper(dentry: dentry->d_parent); |
800 | struct inode *dir = upperdir->d_inode; |
801 | struct dentry *upper; |
802 | struct dentry *opaquedir = NULL; |
803 | int err; |
804 | |
805 | if (!list_empty(head: list)) { |
806 | opaquedir = ovl_clear_empty(dentry, list); |
807 | err = PTR_ERR(ptr: opaquedir); |
808 | if (IS_ERR(ptr: opaquedir)) |
809 | goto out; |
810 | } |
811 | |
812 | inode_lock_nested(inode: dir, subclass: I_MUTEX_PARENT); |
813 | upper = ovl_lookup_upper(ofs, name: dentry->d_name.name, base: upperdir, |
814 | len: dentry->d_name.len); |
815 | err = PTR_ERR(ptr: upper); |
816 | if (IS_ERR(ptr: upper)) |
817 | goto out_unlock; |
818 | |
819 | err = -ESTALE; |
820 | if ((opaquedir && upper != opaquedir) || |
821 | (!opaquedir && !ovl_matches_upper(dentry, upper))) |
822 | goto out_dput_upper; |
823 | |
824 | if (is_dir) |
825 | err = ovl_do_rmdir(ofs, dir, dentry: upper); |
826 | else |
827 | err = ovl_do_unlink(ofs, dir, dentry: upper); |
828 | ovl_dir_modified(dentry: dentry->d_parent, impurity: ovl_type_origin(dentry)); |
829 | |
830 | /* |
831 | * Keeping this dentry hashed would mean having to release |
832 | * upperpath/lowerpath, which could only be done if we are the |
833 | * sole user of this dentry. Too tricky... Just unhash for |
834 | * now. |
835 | */ |
836 | if (!err) |
837 | d_drop(dentry); |
838 | out_dput_upper: |
839 | dput(upper); |
840 | out_unlock: |
841 | inode_unlock(inode: dir); |
842 | dput(opaquedir); |
843 | out: |
844 | return err; |
845 | } |
846 | |
847 | static bool ovl_pure_upper(struct dentry *dentry) |
848 | { |
849 | return !ovl_dentry_lower(dentry) && |
850 | !ovl_test_flag(flag: OVL_WHITEOUTS, inode: d_inode(dentry)); |
851 | } |
852 | |
853 | static void ovl_drop_nlink(struct dentry *dentry) |
854 | { |
855 | struct inode *inode = d_inode(dentry); |
856 | struct dentry *alias; |
857 | |
858 | /* Try to find another, hashed alias */ |
859 | spin_lock(lock: &inode->i_lock); |
860 | hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { |
861 | if (alias != dentry && !d_unhashed(dentry: alias)) |
862 | break; |
863 | } |
864 | spin_unlock(lock: &inode->i_lock); |
865 | |
866 | /* |
867 | * Changes to underlying layers may cause i_nlink to lose sync with |
868 | * reality. In this case prevent the link count from going to zero |
869 | * prematurely. |
870 | */ |
871 | if (inode->i_nlink > !!alias) |
872 | drop_nlink(inode); |
873 | } |
874 | |
875 | static int ovl_do_remove(struct dentry *dentry, bool is_dir) |
876 | { |
877 | int err; |
878 | const struct cred *old_cred; |
879 | bool lower_positive = ovl_lower_positive(dentry); |
880 | LIST_HEAD(list); |
881 | |
882 | /* No need to clean pure upper removed by vfs_rmdir() */ |
883 | if (is_dir && (lower_positive || !ovl_pure_upper(dentry))) { |
884 | err = ovl_check_empty_dir(dentry, list: &list); |
885 | if (err) |
886 | goto out; |
887 | } |
888 | |
889 | err = ovl_copy_up(dentry: dentry->d_parent); |
890 | if (err) |
891 | goto out; |
892 | |
893 | err = ovl_nlink_start(dentry); |
894 | if (err) |
895 | goto out; |
896 | |
897 | old_cred = ovl_override_creds(sb: dentry->d_sb); |
898 | if (!lower_positive) |
899 | err = ovl_remove_upper(dentry, is_dir, list: &list); |
900 | else |
901 | err = ovl_remove_and_whiteout(dentry, list: &list); |
902 | revert_creds(old_cred); |
903 | if (!err) { |
904 | if (is_dir) |
905 | clear_nlink(inode: dentry->d_inode); |
906 | else |
907 | ovl_drop_nlink(dentry); |
908 | } |
909 | ovl_nlink_end(dentry); |
910 | |
911 | /* |
912 | * Copy ctime |
913 | * |
914 | * Note: we fail to update ctime if there was no copy-up, only a |
915 | * whiteout |
916 | */ |
917 | if (ovl_dentry_upper(dentry)) |
918 | ovl_copyattr(to: d_inode(dentry)); |
919 | |
920 | out: |
921 | ovl_cache_free(list: &list); |
922 | return err; |
923 | } |
924 | |
925 | static int ovl_unlink(struct inode *dir, struct dentry *dentry) |
926 | { |
927 | return ovl_do_remove(dentry, is_dir: false); |
928 | } |
929 | |
930 | static int ovl_rmdir(struct inode *dir, struct dentry *dentry) |
931 | { |
932 | return ovl_do_remove(dentry, is_dir: true); |
933 | } |
934 | |
935 | static bool ovl_type_merge_or_lower(struct dentry *dentry) |
936 | { |
937 | enum ovl_path_type type = ovl_path_type(dentry); |
938 | |
939 | return OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type); |
940 | } |
941 | |
942 | static bool ovl_can_move(struct dentry *dentry) |
943 | { |
944 | return ovl_redirect_dir(ofs: OVL_FS(sb: dentry->d_sb)) || |
945 | !d_is_dir(dentry) || !ovl_type_merge_or_lower(dentry); |
946 | } |
947 | |
948 | static char *ovl_get_redirect(struct dentry *dentry, bool abs_redirect) |
949 | { |
950 | char *buf, *ret; |
951 | struct dentry *d, *tmp; |
952 | int buflen = ovl_redirect_max + 1; |
953 | |
954 | if (!abs_redirect) { |
955 | ret = kstrndup(s: dentry->d_name.name, len: dentry->d_name.len, |
956 | GFP_KERNEL); |
957 | goto out; |
958 | } |
959 | |
960 | buf = ret = kmalloc(size: buflen, GFP_KERNEL); |
961 | if (!buf) |
962 | goto out; |
963 | |
964 | buflen--; |
965 | buf[buflen] = '\0'; |
966 | for (d = dget(dentry); !IS_ROOT(d);) { |
967 | const char *name; |
968 | int thislen; |
969 | |
970 | spin_lock(lock: &d->d_lock); |
971 | name = ovl_dentry_get_redirect(dentry: d); |
972 | if (name) { |
973 | thislen = strlen(name); |
974 | } else { |
975 | name = d->d_name.name; |
976 | thislen = d->d_name.len; |
977 | } |
978 | |
979 | /* If path is too long, fall back to userspace move */ |
980 | if (thislen + (name[0] != '/') > buflen) { |
981 | ret = ERR_PTR(error: -EXDEV); |
982 | spin_unlock(lock: &d->d_lock); |
983 | goto out_put; |
984 | } |
985 | |
986 | buflen -= thislen; |
987 | memcpy(&buf[buflen], name, thislen); |
988 | spin_unlock(lock: &d->d_lock); |
989 | tmp = dget_parent(dentry: d); |
990 | |
991 | dput(d); |
992 | d = tmp; |
993 | |
994 | /* Absolute redirect: finished */ |
995 | if (buf[buflen] == '/') |
996 | break; |
997 | buflen--; |
998 | buf[buflen] = '/'; |
999 | } |
1000 | ret = kstrdup(s: &buf[buflen], GFP_KERNEL); |
1001 | out_put: |
1002 | dput(d); |
1003 | kfree(objp: buf); |
1004 | out: |
1005 | return ret ? ret : ERR_PTR(error: -ENOMEM); |
1006 | } |
1007 | |
1008 | static bool ovl_need_absolute_redirect(struct dentry *dentry, bool samedir) |
1009 | { |
1010 | struct dentry *lowerdentry; |
1011 | |
1012 | if (!samedir) |
1013 | return true; |
1014 | |
1015 | if (d_is_dir(dentry)) |
1016 | return false; |
1017 | |
1018 | /* |
1019 | * For non-dir hardlinked files, we need absolute redirects |
1020 | * in general as two upper hardlinks could be in different |
1021 | * dirs. We could put a relative redirect now and convert |
1022 | * it to absolute redirect later. But when nlink > 1 and |
1023 | * indexing is on, that means relative redirect needs to be |
1024 | * converted to absolute during copy up of another lower |
1025 | * hardllink as well. |
1026 | * |
1027 | * So without optimizing too much, just check if lower is |
1028 | * a hard link or not. If lower is hard link, put absolute |
1029 | * redirect. |
1030 | */ |
1031 | lowerdentry = ovl_dentry_lower(dentry); |
1032 | return (d_inode(dentry: lowerdentry)->i_nlink > 1); |
1033 | } |
1034 | |
1035 | static int ovl_set_redirect(struct dentry *dentry, bool samedir) |
1036 | { |
1037 | int err; |
1038 | struct ovl_fs *ofs = OVL_FS(sb: dentry->d_sb); |
1039 | const char *redirect = ovl_dentry_get_redirect(dentry); |
1040 | bool absolute_redirect = ovl_need_absolute_redirect(dentry, samedir); |
1041 | |
1042 | if (redirect && (!absolute_redirect || redirect[0] == '/')) |
1043 | return 0; |
1044 | |
1045 | redirect = ovl_get_redirect(dentry, abs_redirect: absolute_redirect); |
1046 | if (IS_ERR(ptr: redirect)) |
1047 | return PTR_ERR(ptr: redirect); |
1048 | |
1049 | err = ovl_check_setxattr(ofs, upperdentry: ovl_dentry_upper(dentry), |
1050 | ox: OVL_XATTR_REDIRECT, |
1051 | value: redirect, strlen(redirect), xerr: -EXDEV); |
1052 | if (!err) { |
1053 | spin_lock(lock: &dentry->d_lock); |
1054 | ovl_dentry_set_redirect(dentry, redirect); |
1055 | spin_unlock(lock: &dentry->d_lock); |
1056 | } else { |
1057 | kfree(objp: redirect); |
1058 | pr_warn_ratelimited("failed to set redirect (%i)\n" , |
1059 | err); |
1060 | /* Fall back to userspace copy-up */ |
1061 | err = -EXDEV; |
1062 | } |
1063 | return err; |
1064 | } |
1065 | |
1066 | static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, |
1067 | struct dentry *old, struct inode *newdir, |
1068 | struct dentry *new, unsigned int flags) |
1069 | { |
1070 | int err; |
1071 | struct dentry *old_upperdir; |
1072 | struct dentry *new_upperdir; |
1073 | struct dentry *olddentry; |
1074 | struct dentry *newdentry; |
1075 | struct dentry *trap; |
1076 | bool old_opaque; |
1077 | bool new_opaque; |
1078 | bool cleanup_whiteout = false; |
1079 | bool update_nlink = false; |
1080 | bool overwrite = !(flags & RENAME_EXCHANGE); |
1081 | bool is_dir = d_is_dir(dentry: old); |
1082 | bool new_is_dir = d_is_dir(dentry: new); |
1083 | bool samedir = olddir == newdir; |
1084 | struct dentry *opaquedir = NULL; |
1085 | const struct cred *old_cred = NULL; |
1086 | struct ovl_fs *ofs = OVL_FS(sb: old->d_sb); |
1087 | LIST_HEAD(list); |
1088 | |
1089 | err = -EINVAL; |
1090 | if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) |
1091 | goto out; |
1092 | |
1093 | flags &= ~RENAME_NOREPLACE; |
1094 | |
1095 | /* Don't copy up directory trees */ |
1096 | err = -EXDEV; |
1097 | if (!ovl_can_move(dentry: old)) |
1098 | goto out; |
1099 | if (!overwrite && !ovl_can_move(dentry: new)) |
1100 | goto out; |
1101 | |
1102 | if (overwrite && new_is_dir && !ovl_pure_upper(dentry: new)) { |
1103 | err = ovl_check_empty_dir(dentry: new, list: &list); |
1104 | if (err) |
1105 | goto out; |
1106 | } |
1107 | |
1108 | if (overwrite) { |
1109 | if (ovl_lower_positive(dentry: old)) { |
1110 | if (!ovl_dentry_is_whiteout(dentry: new)) { |
1111 | /* Whiteout source */ |
1112 | flags |= RENAME_WHITEOUT; |
1113 | } else { |
1114 | /* Switch whiteouts */ |
1115 | flags |= RENAME_EXCHANGE; |
1116 | } |
1117 | } else if (is_dir && ovl_dentry_is_whiteout(dentry: new)) { |
1118 | flags |= RENAME_EXCHANGE; |
1119 | cleanup_whiteout = true; |
1120 | } |
1121 | } |
1122 | |
1123 | err = ovl_copy_up(dentry: old); |
1124 | if (err) |
1125 | goto out; |
1126 | |
1127 | err = ovl_copy_up(dentry: new->d_parent); |
1128 | if (err) |
1129 | goto out; |
1130 | if (!overwrite) { |
1131 | err = ovl_copy_up(dentry: new); |
1132 | if (err) |
1133 | goto out; |
1134 | } else if (d_inode(dentry: new)) { |
1135 | err = ovl_nlink_start(dentry: new); |
1136 | if (err) |
1137 | goto out; |
1138 | |
1139 | update_nlink = true; |
1140 | } |
1141 | |
1142 | if (!update_nlink) { |
1143 | /* ovl_nlink_start() took ovl_want_write() */ |
1144 | err = ovl_want_write(dentry: old); |
1145 | if (err) |
1146 | goto out; |
1147 | } |
1148 | |
1149 | old_cred = ovl_override_creds(sb: old->d_sb); |
1150 | |
1151 | if (!list_empty(head: &list)) { |
1152 | opaquedir = ovl_clear_empty(dentry: new, list: &list); |
1153 | err = PTR_ERR(ptr: opaquedir); |
1154 | if (IS_ERR(ptr: opaquedir)) { |
1155 | opaquedir = NULL; |
1156 | goto out_revert_creds; |
1157 | } |
1158 | } |
1159 | |
1160 | old_upperdir = ovl_dentry_upper(dentry: old->d_parent); |
1161 | new_upperdir = ovl_dentry_upper(dentry: new->d_parent); |
1162 | |
1163 | if (!samedir) { |
1164 | /* |
1165 | * When moving a merge dir or non-dir with copy up origin into |
1166 | * a new parent, we are marking the new parent dir "impure". |
1167 | * When ovl_iterate() iterates an "impure" upper dir, it will |
1168 | * lookup the origin inodes of the entries to fill d_ino. |
1169 | */ |
1170 | if (ovl_type_origin(dentry: old)) { |
1171 | err = ovl_set_impure(dentry: new->d_parent, upperdentry: new_upperdir); |
1172 | if (err) |
1173 | goto out_revert_creds; |
1174 | } |
1175 | if (!overwrite && ovl_type_origin(dentry: new)) { |
1176 | err = ovl_set_impure(dentry: old->d_parent, upperdentry: old_upperdir); |
1177 | if (err) |
1178 | goto out_revert_creds; |
1179 | } |
1180 | } |
1181 | |
1182 | trap = lock_rename(new_upperdir, old_upperdir); |
1183 | |
1184 | olddentry = ovl_lookup_upper(ofs, name: old->d_name.name, base: old_upperdir, |
1185 | len: old->d_name.len); |
1186 | err = PTR_ERR(ptr: olddentry); |
1187 | if (IS_ERR(ptr: olddentry)) |
1188 | goto out_unlock; |
1189 | |
1190 | err = -ESTALE; |
1191 | if (!ovl_matches_upper(dentry: old, upper: olddentry)) |
1192 | goto out_dput_old; |
1193 | |
1194 | newdentry = ovl_lookup_upper(ofs, name: new->d_name.name, base: new_upperdir, |
1195 | len: new->d_name.len); |
1196 | err = PTR_ERR(ptr: newdentry); |
1197 | if (IS_ERR(ptr: newdentry)) |
1198 | goto out_dput_old; |
1199 | |
1200 | old_opaque = ovl_dentry_is_opaque(dentry: old); |
1201 | new_opaque = ovl_dentry_is_opaque(dentry: new); |
1202 | |
1203 | err = -ESTALE; |
1204 | if (d_inode(dentry: new) && ovl_dentry_upper(dentry: new)) { |
1205 | if (opaquedir) { |
1206 | if (newdentry != opaquedir) |
1207 | goto out_dput; |
1208 | } else { |
1209 | if (!ovl_matches_upper(dentry: new, upper: newdentry)) |
1210 | goto out_dput; |
1211 | } |
1212 | } else { |
1213 | if (!d_is_negative(dentry: newdentry)) { |
1214 | if (!new_opaque || !ovl_upper_is_whiteout(ofs, upperdentry: newdentry)) |
1215 | goto out_dput; |
1216 | } else { |
1217 | if (flags & RENAME_EXCHANGE) |
1218 | goto out_dput; |
1219 | } |
1220 | } |
1221 | |
1222 | if (olddentry == trap) |
1223 | goto out_dput; |
1224 | if (newdentry == trap) |
1225 | goto out_dput; |
1226 | |
1227 | if (olddentry->d_inode == newdentry->d_inode) |
1228 | goto out_dput; |
1229 | |
1230 | err = 0; |
1231 | if (ovl_type_merge_or_lower(dentry: old)) |
1232 | err = ovl_set_redirect(dentry: old, samedir); |
1233 | else if (is_dir && !old_opaque && ovl_type_merge(dentry: new->d_parent)) |
1234 | err = ovl_set_opaque_xerr(dentry: old, upper: olddentry, xerr: -EXDEV); |
1235 | if (err) |
1236 | goto out_dput; |
1237 | |
1238 | if (!overwrite && ovl_type_merge_or_lower(dentry: new)) |
1239 | err = ovl_set_redirect(dentry: new, samedir); |
1240 | else if (!overwrite && new_is_dir && !new_opaque && |
1241 | ovl_type_merge(dentry: old->d_parent)) |
1242 | err = ovl_set_opaque_xerr(dentry: new, upper: newdentry, xerr: -EXDEV); |
1243 | if (err) |
1244 | goto out_dput; |
1245 | |
1246 | err = ovl_do_rename(ofs, olddir: old_upperdir->d_inode, olddentry, |
1247 | newdir: new_upperdir->d_inode, newdentry, flags); |
1248 | if (err) |
1249 | goto out_dput; |
1250 | |
1251 | if (cleanup_whiteout) |
1252 | ovl_cleanup(ofs, wdir: old_upperdir->d_inode, wdentry: newdentry); |
1253 | |
1254 | if (overwrite && d_inode(dentry: new)) { |
1255 | if (new_is_dir) |
1256 | clear_nlink(inode: d_inode(dentry: new)); |
1257 | else |
1258 | ovl_drop_nlink(dentry: new); |
1259 | } |
1260 | |
1261 | ovl_dir_modified(dentry: old->d_parent, impurity: ovl_type_origin(dentry: old) || |
1262 | (!overwrite && ovl_type_origin(dentry: new))); |
1263 | ovl_dir_modified(dentry: new->d_parent, impurity: ovl_type_origin(dentry: old) || |
1264 | (d_inode(dentry: new) && ovl_type_origin(dentry: new))); |
1265 | |
1266 | /* copy ctime: */ |
1267 | ovl_copyattr(to: d_inode(dentry: old)); |
1268 | if (d_inode(dentry: new) && ovl_dentry_upper(dentry: new)) |
1269 | ovl_copyattr(to: d_inode(dentry: new)); |
1270 | |
1271 | out_dput: |
1272 | dput(newdentry); |
1273 | out_dput_old: |
1274 | dput(olddentry); |
1275 | out_unlock: |
1276 | unlock_rename(new_upperdir, old_upperdir); |
1277 | out_revert_creds: |
1278 | revert_creds(old_cred); |
1279 | if (update_nlink) |
1280 | ovl_nlink_end(dentry: new); |
1281 | else |
1282 | ovl_drop_write(dentry: old); |
1283 | out: |
1284 | dput(opaquedir); |
1285 | ovl_cache_free(list: &list); |
1286 | return err; |
1287 | } |
1288 | |
1289 | const struct inode_operations ovl_dir_inode_operations = { |
1290 | .lookup = ovl_lookup, |
1291 | .mkdir = ovl_mkdir, |
1292 | .symlink = ovl_symlink, |
1293 | .unlink = ovl_unlink, |
1294 | .rmdir = ovl_rmdir, |
1295 | .rename = ovl_rename, |
1296 | .link = ovl_link, |
1297 | .setattr = ovl_setattr, |
1298 | .create = ovl_create, |
1299 | .mknod = ovl_mknod, |
1300 | .permission = ovl_permission, |
1301 | .getattr = ovl_getattr, |
1302 | .listxattr = ovl_listxattr, |
1303 | .get_inode_acl = ovl_get_inode_acl, |
1304 | .get_acl = ovl_get_acl, |
1305 | .set_acl = ovl_set_acl, |
1306 | .update_time = ovl_update_time, |
1307 | .fileattr_get = ovl_fileattr_get, |
1308 | .fileattr_set = ovl_fileattr_set, |
1309 | }; |
1310 | |