Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
e9be9d5e MS |
2 | /* |
3 | * | |
4 | * Copyright (C) 2011 Novell Inc. | |
e9be9d5e MS |
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> | |
3ea22a71 | 12 | #include <linux/module.h> |
38b25697 MS |
13 | #include <linux/posix_acl.h> |
14 | #include <linux/posix_acl_xattr.h> | |
6a45b362 | 15 | #include <linux/atomic.h> |
a6c60655 | 16 | #include <linux/ratelimit.h> |
e9be9d5e MS |
17 | #include "overlayfs.h" |
18 | ||
3ea22a71 MS |
19 | static unsigned short ovl_redirect_max = 256; |
20 | module_param_named(redirect_max, ovl_redirect_max, ushort, 0644); | |
253e7483 | 21 | MODULE_PARM_DESC(redirect_max, |
3ea22a71 MS |
22 | "Maximum length of absolute redirect xattr value"); |
23 | ||
4120fe64 VG |
24 | static int ovl_set_redirect(struct dentry *dentry, bool samedir); |
25 | ||
415543d5 | 26 | int ovl_cleanup(struct inode *wdir, struct dentry *wdentry) |
e9be9d5e MS |
27 | { |
28 | int err; | |
29 | ||
30 | dget(wdentry); | |
e36cb0b8 | 31 | if (d_is_dir(wdentry)) |
e9be9d5e MS |
32 | err = ovl_do_rmdir(wdir, wdentry); |
33 | else | |
34 | err = ovl_do_unlink(wdir, wdentry); | |
35 | dput(wdentry); | |
36 | ||
37 | if (err) { | |
1bd0a3ae | 38 | pr_err("cleanup of '%pd2' failed (%i)\n", |
e9be9d5e MS |
39 | wdentry, err); |
40 | } | |
415543d5 AG |
41 | |
42 | return err; | |
e9be9d5e MS |
43 | } |
44 | ||
cad218ab | 45 | struct dentry *ovl_lookup_temp(struct dentry *workdir) |
e9be9d5e MS |
46 | { |
47 | struct dentry *temp; | |
48 | char name[20]; | |
6a45b362 | 49 | static atomic_t temp_id = ATOMIC_INIT(0); |
e9be9d5e | 50 | |
6a45b362 RW |
51 | /* counter is allowed to wrap, since temp dentries are ephemeral */ |
52 | snprintf(name, sizeof(name), "#%x", atomic_inc_return(&temp_id)); | |
e9be9d5e MS |
53 | |
54 | temp = lookup_one_len(name, workdir, strlen(name)); | |
55 | if (!IS_ERR(temp) && temp->d_inode) { | |
1bd0a3ae | 56 | pr_err("workdir/%s already exists\n", name); |
e9be9d5e MS |
57 | dput(temp); |
58 | temp = ERR_PTR(-EIO); | |
59 | } | |
60 | ||
61 | return temp; | |
62 | } | |
63 | ||
64 | /* caller holds i_mutex on workdir */ | |
c21c839b | 65 | static struct dentry *ovl_whiteout(struct ovl_fs *ofs) |
e9be9d5e MS |
66 | { |
67 | int err; | |
68 | struct dentry *whiteout; | |
c21c839b | 69 | struct dentry *workdir = ofs->workdir; |
e9be9d5e MS |
70 | struct inode *wdir = workdir->d_inode; |
71 | ||
c21c839b CX |
72 | if (!ofs->whiteout) { |
73 | whiteout = ovl_lookup_temp(workdir); | |
74 | if (IS_ERR(whiteout)) | |
75 | goto out; | |
e9be9d5e | 76 | |
c21c839b CX |
77 | err = ovl_do_whiteout(wdir, whiteout); |
78 | if (err) { | |
79 | dput(whiteout); | |
80 | whiteout = ERR_PTR(err); | |
81 | goto out; | |
82 | } | |
83 | ofs->whiteout = whiteout; | |
e9be9d5e MS |
84 | } |
85 | ||
c21c839b CX |
86 | if (ofs->share_whiteout) { |
87 | whiteout = ovl_lookup_temp(workdir); | |
88 | if (IS_ERR(whiteout)) | |
89 | goto out; | |
90 | ||
91 | err = ovl_do_link(ofs->whiteout, wdir, 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->share_whiteout = false; | |
99 | } | |
100 | dput(whiteout); | |
101 | } | |
102 | whiteout = ofs->whiteout; | |
103 | ofs->whiteout = NULL; | |
104 | out: | |
e9be9d5e MS |
105 | return whiteout; |
106 | } | |
107 | ||
e7dd0e71 | 108 | /* Caller must hold i_mutex on both workdir and dir */ |
c21c839b | 109 | int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, |
e7dd0e71 AG |
110 | struct dentry *dentry) |
111 | { | |
c21c839b | 112 | struct inode *wdir = ofs->workdir->d_inode; |
e7dd0e71 AG |
113 | struct dentry *whiteout; |
114 | int err; | |
115 | int flags = 0; | |
116 | ||
c21c839b | 117 | whiteout = ovl_whiteout(ofs); |
e7dd0e71 AG |
118 | err = PTR_ERR(whiteout); |
119 | if (IS_ERR(whiteout)) | |
120 | return err; | |
121 | ||
122 | if (d_is_dir(dentry)) | |
123 | flags = RENAME_EXCHANGE; | |
124 | ||
125 | err = ovl_do_rename(wdir, whiteout, dir, dentry, flags); | |
126 | if (err) | |
127 | goto kill_whiteout; | |
128 | if (flags) | |
129 | ovl_cleanup(wdir, dentry); | |
130 | ||
131 | out: | |
132 | dput(whiteout); | |
133 | return err; | |
134 | ||
135 | kill_whiteout: | |
136 | ovl_cleanup(wdir, whiteout); | |
137 | goto out; | |
138 | } | |
139 | ||
f73cc77c AV |
140 | static int ovl_mkdir_real(struct inode *dir, struct dentry **newdentry, |
141 | umode_t mode) | |
142 | { | |
143 | int err; | |
144 | struct dentry *d, *dentry = *newdentry; | |
145 | ||
146 | err = ovl_do_mkdir(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 = lookup_one_len(dentry->d_name.name, dentry->d_parent, | |
159 | dentry->d_name.len); | |
160 | if (IS_ERR(d)) { | |
1bd0a3ae | 161 | pr_warn("failed lookup after mkdir (%pd2, err=%i).\n", |
f73cc77c AV |
162 | dentry, err); |
163 | return PTR_ERR(d); | |
164 | } | |
165 | dput(dentry); | |
166 | *newdentry = d; | |
167 | ||
168 | return 0; | |
169 | } | |
170 | ||
95a1c815 MS |
171 | struct dentry *ovl_create_real(struct inode *dir, struct dentry *newdentry, |
172 | struct ovl_cattr *attr) | |
e9be9d5e MS |
173 | { |
174 | int err; | |
175 | ||
95a1c815 MS |
176 | if (IS_ERR(newdentry)) |
177 | return newdentry; | |
178 | ||
179 | err = -ESTALE; | |
e9be9d5e | 180 | if (newdentry->d_inode) |
95a1c815 | 181 | goto out; |
e9be9d5e | 182 | |
471ec5dc AG |
183 | if (attr->hardlink) { |
184 | err = ovl_do_link(attr->hardlink, dir, newdentry); | |
e9be9d5e | 185 | } else { |
32a3d848 | 186 | switch (attr->mode & S_IFMT) { |
e9be9d5e | 187 | case S_IFREG: |
6cf00764 | 188 | err = ovl_do_create(dir, newdentry, attr->mode); |
e9be9d5e MS |
189 | break; |
190 | ||
191 | case S_IFDIR: | |
f73cc77c AV |
192 | /* mkdir is special... */ |
193 | err = ovl_mkdir_real(dir, &newdentry, attr->mode); | |
e9be9d5e MS |
194 | break; |
195 | ||
196 | case S_IFCHR: | |
197 | case S_IFBLK: | |
198 | case S_IFIFO: | |
199 | case S_IFSOCK: | |
6cf00764 AG |
200 | err = ovl_do_mknod(dir, newdentry, attr->mode, |
201 | attr->rdev); | |
e9be9d5e MS |
202 | break; |
203 | ||
204 | case S_IFLNK: | |
6cf00764 | 205 | err = ovl_do_symlink(dir, newdentry, attr->link); |
e9be9d5e MS |
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 | */ | |
dd8ac699 | 217 | err = -EIO; |
e9be9d5e | 218 | } |
95a1c815 MS |
219 | out: |
220 | if (err) { | |
221 | dput(newdentry); | |
222 | return ERR_PTR(err); | |
223 | } | |
224 | return newdentry; | |
e9be9d5e MS |
225 | } |
226 | ||
137ec526 AG |
227 | struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr) |
228 | { | |
229 | return ovl_create_real(d_inode(workdir), ovl_lookup_temp(workdir), | |
230 | attr); | |
231 | } | |
232 | ||
21a22878 AG |
233 | static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper, |
234 | int xerr) | |
e9be9d5e | 235 | { |
5cf5b477 MS |
236 | int err; |
237 | ||
21a22878 | 238 | err = ovl_check_setxattr(dentry, upper, OVL_XATTR_OPAQUE, "y", 1, xerr); |
5cf5b477 MS |
239 | if (!err) |
240 | ovl_dentry_set_opaque(dentry); | |
241 | ||
242 | return err; | |
e9be9d5e MS |
243 | } |
244 | ||
21a22878 AG |
245 | static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) |
246 | { | |
247 | /* | |
248 | * Fail with -EIO when trying to create opaque dir and upper doesn't | |
249 | * support xattrs. ovl_rename() calls ovl_set_opaque_xerr(-EXDEV) to | |
250 | * return a specific error for noxattr case. | |
251 | */ | |
252 | return ovl_set_opaque_xerr(dentry, upperdentry, -EIO); | |
253 | } | |
254 | ||
01b39dcc AG |
255 | /* |
256 | * Common operations required to be done after creation of file on upper. | |
257 | * If @hardlink is false, then @inode is a pre-allocated inode, we may or | |
258 | * may not use to instantiate the new dentry. | |
259 | */ | |
260 | static int ovl_instantiate(struct dentry *dentry, struct inode *inode, | |
261 | struct dentry *newdentry, bool hardlink) | |
72e48481 | 262 | { |
01b39dcc AG |
263 | struct ovl_inode_params oip = { |
264 | .upperdentry = newdentry, | |
265 | .newinode = inode, | |
266 | }; | |
267 | ||
d9854c87 | 268 | ovl_dir_modified(dentry->d_parent, false); |
55acc661 | 269 | ovl_dentry_set_upper_alias(dentry); |
f4288844 MS |
270 | ovl_dentry_update_reval(dentry, newdentry, |
271 | DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); | |
272 | ||
51f7e52d | 273 | if (!hardlink) { |
01b39dcc AG |
274 | /* |
275 | * ovl_obtain_alias() can be called after ovl_create_real() | |
276 | * and before we get here, so we may get an inode from cache | |
277 | * with the same real upperdentry that is not the inode we | |
278 | * pre-allocated. In this case we will use the cached inode | |
279 | * to instantiate the new dentry. | |
280 | * | |
281 | * XXX: if we ever use ovl_obtain_alias() to decode directory | |
282 | * file handles, need to use ovl_get_inode_locked() and | |
283 | * d_instantiate_new() here to prevent from creating two | |
284 | * hashed directory inode aliases. | |
285 | */ | |
286 | inode = ovl_get_inode(dentry->d_sb, &oip); | |
acf3062a | 287 | if (IS_ERR(inode)) |
01b39dcc | 288 | return PTR_ERR(inode); |
28166ab3 VG |
289 | if (inode == oip.newinode) |
290 | ovl_set_flag(OVL_UPPERDATA, inode); | |
51f7e52d | 291 | } else { |
09d8b586 MS |
292 | WARN_ON(ovl_inode_real(inode) != d_inode(newdentry)); |
293 | dput(newdentry); | |
51f7e52d MS |
294 | inc_nlink(inode); |
295 | } | |
01b39dcc | 296 | |
72e48481 | 297 | d_instantiate(dentry, inode); |
01b39dcc | 298 | if (inode != oip.newinode) { |
1bd0a3ae | 299 | pr_warn_ratelimited("newly created inode found in cache (%pd2)\n", |
01b39dcc AG |
300 | dentry); |
301 | } | |
302 | ||
5b6c9053 AG |
303 | /* Force lookup of new upper hardlink to find its lower */ |
304 | if (hardlink) | |
305 | d_drop(dentry); | |
01b39dcc AG |
306 | |
307 | return 0; | |
72e48481 VG |
308 | } |
309 | ||
97c684cc AG |
310 | static bool ovl_type_merge(struct dentry *dentry) |
311 | { | |
312 | return OVL_TYPE_MERGE(ovl_path_type(dentry)); | |
313 | } | |
314 | ||
ee1d6d37 AG |
315 | static bool ovl_type_origin(struct dentry *dentry) |
316 | { | |
317 | return OVL_TYPE_ORIGIN(ovl_path_type(dentry)); | |
318 | } | |
319 | ||
e9be9d5e | 320 | static int ovl_create_upper(struct dentry *dentry, struct inode *inode, |
471ec5dc | 321 | struct ovl_cattr *attr) |
e9be9d5e MS |
322 | { |
323 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
324 | struct inode *udir = upperdir->d_inode; | |
325 | struct dentry *newdentry; | |
326 | int err; | |
327 | ||
471ec5dc | 328 | if (!attr->hardlink && !IS_POSIXACL(udir)) |
32a3d848 | 329 | attr->mode &= ~current_umask(); |
38b25697 | 330 | |
5955102c | 331 | inode_lock_nested(udir, I_MUTEX_PARENT); |
95a1c815 MS |
332 | newdentry = ovl_create_real(udir, |
333 | lookup_one_len(dentry->d_name.name, | |
334 | upperdir, | |
335 | dentry->d_name.len), | |
336 | attr); | |
e9be9d5e MS |
337 | err = PTR_ERR(newdentry); |
338 | if (IS_ERR(newdentry)) | |
339 | goto out_unlock; | |
e9be9d5e | 340 | |
4a99f3c8 | 341 | if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry)) { |
97c684cc AG |
342 | /* Setting opaque here is just an optimization, allow to fail */ |
343 | ovl_set_opaque(dentry, newdentry); | |
344 | } | |
345 | ||
01b39dcc AG |
346 | err = ovl_instantiate(dentry, inode, newdentry, !!attr->hardlink); |
347 | if (err) | |
348 | goto out_cleanup; | |
e9be9d5e | 349 | out_unlock: |
5955102c | 350 | inode_unlock(udir); |
e9be9d5e | 351 | return err; |
01b39dcc AG |
352 | |
353 | out_cleanup: | |
354 | ovl_cleanup(udir, newdentry); | |
355 | dput(newdentry); | |
356 | goto out_unlock; | |
e9be9d5e MS |
357 | } |
358 | ||
e9be9d5e MS |
359 | static struct dentry *ovl_clear_empty(struct dentry *dentry, |
360 | struct list_head *list) | |
361 | { | |
362 | struct dentry *workdir = ovl_workdir(dentry); | |
363 | struct inode *wdir = workdir->d_inode; | |
364 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
365 | struct inode *udir = upperdir->d_inode; | |
366 | struct path upperpath; | |
367 | struct dentry *upper; | |
368 | struct dentry *opaquedir; | |
369 | struct kstat stat; | |
370 | int err; | |
371 | ||
cc6f67bc MS |
372 | if (WARN_ON(!workdir)) |
373 | return ERR_PTR(-EROFS); | |
374 | ||
e9be9d5e MS |
375 | err = ovl_lock_rename_workdir(workdir, upperdir); |
376 | if (err) | |
377 | goto out; | |
378 | ||
379 | ovl_path_upper(dentry, &upperpath); | |
a528d35e DH |
380 | err = vfs_getattr(&upperpath, &stat, |
381 | STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); | |
e9be9d5e MS |
382 | if (err) |
383 | goto out_unlock; | |
384 | ||
385 | err = -ESTALE; | |
386 | if (!S_ISDIR(stat.mode)) | |
387 | goto out_unlock; | |
388 | upper = upperpath.dentry; | |
389 | if (upper->d_parent->d_inode != udir) | |
390 | goto out_unlock; | |
391 | ||
137ec526 | 392 | opaquedir = ovl_create_temp(workdir, OVL_CATTR(stat.mode)); |
e9be9d5e MS |
393 | err = PTR_ERR(opaquedir); |
394 | if (IS_ERR(opaquedir)) | |
395 | goto out_unlock; | |
396 | ||
e9be9d5e MS |
397 | err = ovl_copy_xattr(upper, opaquedir); |
398 | if (err) | |
399 | goto out_cleanup; | |
400 | ||
5cf5b477 | 401 | err = ovl_set_opaque(dentry, opaquedir); |
e9be9d5e MS |
402 | if (err) |
403 | goto out_cleanup; | |
404 | ||
5955102c | 405 | inode_lock(opaquedir->d_inode); |
e9be9d5e | 406 | err = ovl_set_attr(opaquedir, &stat); |
5955102c | 407 | inode_unlock(opaquedir->d_inode); |
e9be9d5e MS |
408 | if (err) |
409 | goto out_cleanup; | |
410 | ||
411 | err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE); | |
412 | if (err) | |
413 | goto out_cleanup; | |
414 | ||
415 | ovl_cleanup_whiteouts(upper, list); | |
416 | ovl_cleanup(wdir, upper); | |
417 | unlock_rename(workdir, upperdir); | |
418 | ||
419 | /* dentry's upper doesn't match now, get rid of it */ | |
420 | d_drop(dentry); | |
421 | ||
422 | return opaquedir; | |
423 | ||
424 | out_cleanup: | |
425 | ovl_cleanup(wdir, opaquedir); | |
e9be9d5e MS |
426 | dput(opaquedir); |
427 | out_unlock: | |
428 | unlock_rename(workdir, upperdir); | |
429 | out: | |
430 | return ERR_PTR(err); | |
431 | } | |
432 | ||
38b25697 MS |
433 | static int ovl_set_upper_acl(struct dentry *upperdentry, const char *name, |
434 | const struct posix_acl *acl) | |
435 | { | |
436 | void *buffer; | |
437 | size_t size; | |
438 | int err; | |
439 | ||
440 | if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl) | |
441 | return 0; | |
442 | ||
14fa0856 | 443 | size = posix_acl_xattr_size(acl->a_count); |
38b25697 MS |
444 | buffer = kmalloc(size, GFP_KERNEL); |
445 | if (!buffer) | |
446 | return -ENOMEM; | |
447 | ||
14fa0856 | 448 | err = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); |
38b25697 MS |
449 | if (err < 0) |
450 | goto out_free; | |
451 | ||
452 | err = vfs_setxattr(upperdentry, name, buffer, size, XATTR_CREATE); | |
453 | out_free: | |
454 | kfree(buffer); | |
455 | return err; | |
456 | } | |
457 | ||
e9be9d5e | 458 | static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, |
471ec5dc | 459 | struct ovl_cattr *cattr) |
e9be9d5e MS |
460 | { |
461 | struct dentry *workdir = ovl_workdir(dentry); | |
462 | struct inode *wdir = workdir->d_inode; | |
463 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
464 | struct inode *udir = upperdir->d_inode; | |
465 | struct dentry *upper; | |
466 | struct dentry *newdentry; | |
467 | int err; | |
38b25697 | 468 | struct posix_acl *acl, *default_acl; |
471ec5dc | 469 | bool hardlink = !!cattr->hardlink; |
e9be9d5e | 470 | |
cc6f67bc MS |
471 | if (WARN_ON(!workdir)) |
472 | return -EROFS; | |
473 | ||
38b25697 MS |
474 | if (!hardlink) { |
475 | err = posix_acl_create(dentry->d_parent->d_inode, | |
32a3d848 | 476 | &cattr->mode, &default_acl, &acl); |
38b25697 MS |
477 | if (err) |
478 | return err; | |
479 | } | |
480 | ||
e9be9d5e MS |
481 | err = ovl_lock_rename_workdir(workdir, upperdir); |
482 | if (err) | |
483 | goto out; | |
484 | ||
e9be9d5e MS |
485 | upper = lookup_one_len(dentry->d_name.name, upperdir, |
486 | dentry->d_name.len); | |
487 | err = PTR_ERR(upper); | |
488 | if (IS_ERR(upper)) | |
95a1c815 | 489 | goto out_unlock; |
e9be9d5e | 490 | |
5e127580 MS |
491 | err = -ESTALE; |
492 | if (d_is_negative(upper) || !IS_WHITEOUT(d_inode(upper))) | |
493 | goto out_dput; | |
494 | ||
137ec526 | 495 | newdentry = ovl_create_temp(workdir, cattr); |
95a1c815 MS |
496 | err = PTR_ERR(newdentry); |
497 | if (IS_ERR(newdentry)) | |
498 | goto out_dput; | |
e9be9d5e | 499 | |
bb0d2b8a MS |
500 | /* |
501 | * mode could have been mutilated due to umask (e.g. sgid directory) | |
502 | */ | |
51f7e52d | 503 | if (!hardlink && |
32a3d848 AV |
504 | !S_ISLNK(cattr->mode) && |
505 | newdentry->d_inode->i_mode != cattr->mode) { | |
bb0d2b8a MS |
506 | struct iattr attr = { |
507 | .ia_valid = ATTR_MODE, | |
32a3d848 | 508 | .ia_mode = cattr->mode, |
bb0d2b8a MS |
509 | }; |
510 | inode_lock(newdentry->d_inode); | |
511 | err = notify_change(newdentry, &attr, NULL); | |
512 | inode_unlock(newdentry->d_inode); | |
513 | if (err) | |
514 | goto out_cleanup; | |
515 | } | |
38b25697 MS |
516 | if (!hardlink) { |
517 | err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_ACCESS, | |
518 | acl); | |
519 | if (err) | |
520 | goto out_cleanup; | |
521 | ||
522 | err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_DEFAULT, | |
523 | default_acl); | |
524 | if (err) | |
525 | goto out_cleanup; | |
526 | } | |
bb0d2b8a | 527 | |
32a3d848 | 528 | if (!hardlink && S_ISDIR(cattr->mode)) { |
5cf5b477 | 529 | err = ovl_set_opaque(dentry, newdentry); |
e9be9d5e MS |
530 | if (err) |
531 | goto out_cleanup; | |
532 | ||
533 | err = ovl_do_rename(wdir, newdentry, udir, upper, | |
534 | RENAME_EXCHANGE); | |
535 | if (err) | |
536 | goto out_cleanup; | |
537 | ||
538 | ovl_cleanup(wdir, upper); | |
539 | } else { | |
540 | err = ovl_do_rename(wdir, newdentry, udir, upper, 0); | |
541 | if (err) | |
542 | goto out_cleanup; | |
543 | } | |
01b39dcc AG |
544 | err = ovl_instantiate(dentry, inode, newdentry, hardlink); |
545 | if (err) | |
546 | goto out_cleanup; | |
e9be9d5e | 547 | out_dput: |
95a1c815 | 548 | dput(upper); |
e9be9d5e MS |
549 | out_unlock: |
550 | unlock_rename(workdir, upperdir); | |
551 | out: | |
38b25697 MS |
552 | if (!hardlink) { |
553 | posix_acl_release(acl); | |
554 | posix_acl_release(default_acl); | |
555 | } | |
e9be9d5e MS |
556 | return err; |
557 | ||
558 | out_cleanup: | |
559 | ovl_cleanup(wdir, newdentry); | |
95a1c815 MS |
560 | dput(newdentry); |
561 | goto out_dput; | |
e9be9d5e MS |
562 | } |
563 | ||
51f7e52d | 564 | static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, |
471ec5dc | 565 | struct ovl_cattr *attr, bool origin) |
e9be9d5e MS |
566 | { |
567 | int err; | |
1175b6b8 VG |
568 | const struct cred *old_cred; |
569 | struct cred *override_cred; | |
ea3dad18 | 570 | struct dentry *parent = dentry->d_parent; |
e9be9d5e | 571 | |
ea3dad18 | 572 | err = ovl_copy_up(parent); |
e9be9d5e | 573 | if (err) |
51f7e52d | 574 | return err; |
bb0d2b8a | 575 | |
1175b6b8 | 576 | old_cred = ovl_override_creds(dentry->d_sb); |
ea3dad18 AG |
577 | |
578 | /* | |
579 | * When linking a file with copy up origin into a new parent, mark the | |
580 | * new parent dir "impure". | |
581 | */ | |
582 | if (origin) { | |
583 | err = ovl_set_impure(parent, ovl_dentry_upper(parent)); | |
584 | if (err) | |
585 | goto out_revert_creds; | |
586 | } | |
587 | ||
1175b6b8 VG |
588 | err = -ENOMEM; |
589 | override_cred = prepare_creds(); | |
590 | if (override_cred) { | |
bb0d2b8a MS |
591 | override_cred->fsuid = inode->i_uid; |
592 | override_cred->fsgid = inode->i_gid; | |
471ec5dc | 593 | if (!attr->hardlink) { |
2602625b | 594 | err = security_dentry_create_files_as(dentry, |
32a3d848 | 595 | attr->mode, &dentry->d_name, old_cred, |
2602625b VG |
596 | override_cred); |
597 | if (err) { | |
598 | put_cred(override_cred); | |
599 | goto out_revert_creds; | |
600 | } | |
601 | } | |
1175b6b8 VG |
602 | put_cred(override_creds(override_cred)); |
603 | put_cred(override_cred); | |
604 | ||
c412ce49 | 605 | if (!ovl_dentry_is_whiteout(dentry)) |
471ec5dc | 606 | err = ovl_create_upper(dentry, inode, attr); |
1175b6b8 | 607 | else |
471ec5dc | 608 | err = ovl_create_over_whiteout(dentry, inode, attr); |
e9be9d5e | 609 | } |
2602625b | 610 | out_revert_creds: |
1175b6b8 | 611 | revert_creds(old_cred); |
e9be9d5e MS |
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; | |
51f7e52d | 619 | struct inode *inode; |
471ec5dc | 620 | struct ovl_cattr attr = { |
51f7e52d | 621 | .rdev = rdev, |
32a3d848 | 622 | .link = link, |
51f7e52d | 623 | }; |
e9be9d5e MS |
624 | |
625 | err = ovl_want_write(dentry); | |
51f7e52d MS |
626 | if (err) |
627 | goto out; | |
628 | ||
01b39dcc | 629 | /* Preallocate inode to be used by ovl_get_inode() */ |
51f7e52d | 630 | err = -ENOMEM; |
ca4c8a3a | 631 | inode = ovl_new_inode(dentry->d_sb, mode, rdev); |
51f7e52d MS |
632 | if (!inode) |
633 | goto out_drop_write; | |
634 | ||
6faf05c2 MS |
635 | spin_lock(&inode->i_lock); |
636 | inode->i_state |= I_CREATING; | |
637 | spin_unlock(&inode->i_lock); | |
638 | ||
51f7e52d | 639 | inode_init_owner(inode, dentry->d_parent->d_inode, mode); |
32a3d848 | 640 | attr.mode = inode->i_mode; |
51f7e52d | 641 | |
471ec5dc | 642 | err = ovl_create_or_link(dentry, inode, &attr, false); |
01b39dcc AG |
643 | /* Did we end up using the preallocated inode? */ |
644 | if (inode != d_inode(dentry)) | |
51f7e52d | 645 | iput(inode); |
e9be9d5e | 646 | |
51f7e52d MS |
647 | out_drop_write: |
648 | ovl_drop_write(dentry); | |
649 | out: | |
e9be9d5e MS |
650 | return err; |
651 | } | |
652 | ||
653 | static int ovl_create(struct inode *dir, struct dentry *dentry, umode_t mode, | |
654 | bool excl) | |
655 | { | |
656 | return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL); | |
657 | } | |
658 | ||
659 | static int ovl_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) | |
660 | { | |
661 | return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL); | |
662 | } | |
663 | ||
664 | static int ovl_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, | |
665 | dev_t rdev) | |
666 | { | |
667 | /* Don't allow creation of "whiteout" on overlay */ | |
668 | if (S_ISCHR(mode) && rdev == WHITEOUT_DEV) | |
669 | return -EPERM; | |
670 | ||
671 | return ovl_create_object(dentry, mode, rdev, NULL); | |
672 | } | |
673 | ||
674 | static int ovl_symlink(struct inode *dir, struct dentry *dentry, | |
675 | const char *link) | |
676 | { | |
677 | return ovl_create_object(dentry, S_IFLNK, 0, link); | |
678 | } | |
679 | ||
91ff20f3 AG |
680 | static int ovl_set_link_redirect(struct dentry *dentry) |
681 | { | |
682 | const struct cred *old_cred; | |
683 | int err; | |
684 | ||
685 | old_cred = ovl_override_creds(dentry->d_sb); | |
686 | err = ovl_set_redirect(dentry, false); | |
687 | revert_creds(old_cred); | |
688 | ||
689 | return err; | |
690 | } | |
691 | ||
e9be9d5e MS |
692 | static int ovl_link(struct dentry *old, struct inode *newdir, |
693 | struct dentry *new) | |
694 | { | |
695 | int err; | |
51f7e52d | 696 | struct inode *inode; |
e9be9d5e MS |
697 | |
698 | err = ovl_want_write(old); | |
699 | if (err) | |
700 | goto out; | |
701 | ||
702 | err = ovl_copy_up(old); | |
703 | if (err) | |
704 | goto out_drop_write; | |
705 | ||
6cd07870 AG |
706 | err = ovl_copy_up(new->d_parent); |
707 | if (err) | |
708 | goto out_drop_write; | |
709 | ||
4120fe64 | 710 | if (ovl_is_metacopy_dentry(old)) { |
91ff20f3 | 711 | err = ovl_set_link_redirect(old); |
4120fe64 VG |
712 | if (err) |
713 | goto out_drop_write; | |
714 | } | |
715 | ||
0e32992f | 716 | err = ovl_nlink_start(old); |
5f8415d6 AG |
717 | if (err) |
718 | goto out_drop_write; | |
719 | ||
51f7e52d MS |
720 | inode = d_inode(old); |
721 | ihold(inode); | |
722 | ||
471ec5dc AG |
723 | err = ovl_create_or_link(new, inode, |
724 | &(struct ovl_cattr) {.hardlink = ovl_dentry_upper(old)}, | |
725 | ovl_type_origin(old)); | |
51f7e52d MS |
726 | if (err) |
727 | iput(inode); | |
e9be9d5e | 728 | |
0e32992f | 729 | ovl_nlink_end(old); |
e9be9d5e MS |
730 | out_drop_write: |
731 | ovl_drop_write(old); | |
732 | out: | |
733 | return err; | |
734 | } | |
735 | ||
9020df37 MS |
736 | static bool ovl_matches_upper(struct dentry *dentry, struct dentry *upper) |
737 | { | |
738 | return d_inode(ovl_dentry_upper(dentry)) == d_inode(upper); | |
739 | } | |
740 | ||
6d0a8a90 AG |
741 | static int ovl_remove_and_whiteout(struct dentry *dentry, |
742 | struct list_head *list) | |
e9be9d5e | 743 | { |
c21c839b | 744 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e | 745 | struct dentry *workdir = ovl_workdir(dentry); |
e9be9d5e | 746 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); |
e9be9d5e MS |
747 | struct dentry *upper; |
748 | struct dentry *opaquedir = NULL; | |
749 | int err; | |
750 | ||
cc6f67bc MS |
751 | if (WARN_ON(!workdir)) |
752 | return -EROFS; | |
753 | ||
6d0a8a90 AG |
754 | if (!list_empty(list)) { |
755 | opaquedir = ovl_clear_empty(dentry, list); | |
30c17ebf MS |
756 | err = PTR_ERR(opaquedir); |
757 | if (IS_ERR(opaquedir)) | |
758 | goto out; | |
e9be9d5e MS |
759 | } |
760 | ||
761 | err = ovl_lock_rename_workdir(workdir, upperdir); | |
762 | if (err) | |
763 | goto out_dput; | |
764 | ||
cfc9fde0 MP |
765 | upper = lookup_one_len(dentry->d_name.name, upperdir, |
766 | dentry->d_name.len); | |
767 | err = PTR_ERR(upper); | |
768 | if (IS_ERR(upper)) | |
e9be9d5e MS |
769 | goto out_unlock; |
770 | ||
cfc9fde0 MP |
771 | err = -ESTALE; |
772 | if ((opaquedir && upper != opaquedir) || | |
773 | (!opaquedir && ovl_dentry_upper(dentry) && | |
9020df37 | 774 | !ovl_matches_upper(dentry, upper))) { |
cfc9fde0 MP |
775 | goto out_dput_upper; |
776 | } | |
e9be9d5e | 777 | |
c21c839b | 778 | err = ovl_cleanup_and_whiteout(ofs, d_inode(upperdir), upper); |
cfc9fde0 | 779 | if (err) |
e7dd0e71 | 780 | goto out_d_drop; |
e9be9d5e | 781 | |
d9854c87 | 782 | ovl_dir_modified(dentry->d_parent, true); |
e9be9d5e MS |
783 | out_d_drop: |
784 | d_drop(dentry); | |
cfc9fde0 MP |
785 | out_dput_upper: |
786 | dput(upper); | |
e9be9d5e MS |
787 | out_unlock: |
788 | unlock_rename(workdir, upperdir); | |
789 | out_dput: | |
790 | dput(opaquedir); | |
791 | out: | |
792 | return err; | |
e9be9d5e MS |
793 | } |
794 | ||
6d0a8a90 AG |
795 | static int ovl_remove_upper(struct dentry *dentry, bool is_dir, |
796 | struct list_head *list) | |
e9be9d5e MS |
797 | { |
798 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
799 | struct inode *dir = upperdir->d_inode; | |
11f37104 | 800 | struct dentry *upper; |
d1595119 | 801 | struct dentry *opaquedir = NULL; |
e9be9d5e MS |
802 | int err; |
803 | ||
6d0a8a90 AG |
804 | if (!list_empty(list)) { |
805 | opaquedir = ovl_clear_empty(dentry, list); | |
d1595119 AG |
806 | err = PTR_ERR(opaquedir); |
807 | if (IS_ERR(opaquedir)) | |
808 | goto out; | |
809 | } | |
810 | ||
5955102c | 811 | inode_lock_nested(dir, I_MUTEX_PARENT); |
11f37104 MS |
812 | upper = lookup_one_len(dentry->d_name.name, upperdir, |
813 | dentry->d_name.len); | |
814 | err = PTR_ERR(upper); | |
815 | if (IS_ERR(upper)) | |
816 | goto out_unlock; | |
817 | ||
e9be9d5e | 818 | err = -ESTALE; |
d1595119 | 819 | if ((opaquedir && upper != opaquedir) || |
9020df37 | 820 | (!opaquedir && !ovl_matches_upper(dentry, upper))) |
d1595119 AG |
821 | goto out_dput_upper; |
822 | ||
823 | if (is_dir) | |
824 | err = vfs_rmdir(dir, upper); | |
825 | else | |
826 | err = vfs_unlink(dir, upper, NULL); | |
d9854c87 | 827 | ovl_dir_modified(dentry->d_parent, ovl_type_origin(dentry)); |
e9be9d5e MS |
828 | |
829 | /* | |
830 | * Keeping this dentry hashed would mean having to release | |
831 | * upperpath/lowerpath, which could only be done if we are the | |
832 | * sole user of this dentry. Too tricky... Just unhash for | |
833 | * now. | |
834 | */ | |
ce9113bb RW |
835 | if (!err) |
836 | d_drop(dentry); | |
d1595119 AG |
837 | out_dput_upper: |
838 | dput(upper); | |
11f37104 | 839 | out_unlock: |
5955102c | 840 | inode_unlock(dir); |
d1595119 AG |
841 | dput(opaquedir); |
842 | out: | |
e9be9d5e MS |
843 | return err; |
844 | } | |
845 | ||
6d0a8a90 AG |
846 | static bool ovl_pure_upper(struct dentry *dentry) |
847 | { | |
848 | return !ovl_dentry_lower(dentry) && | |
849 | !ovl_test_flag(OVL_WHITEOUTS, d_inode(dentry)); | |
850 | } | |
851 | ||
83552eac MS |
852 | static void ovl_drop_nlink(struct dentry *dentry) |
853 | { | |
854 | struct inode *inode = d_inode(dentry); | |
855 | struct dentry *alias; | |
856 | ||
857 | /* Try to find another, hashed alias */ | |
858 | spin_lock(&inode->i_lock); | |
859 | hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { | |
860 | if (alias != dentry && !d_unhashed(alias)) | |
861 | break; | |
862 | } | |
863 | spin_unlock(&inode->i_lock); | |
864 | ||
865 | /* | |
866 | * Changes to underlying layers may cause i_nlink to lose sync with | |
867 | * reality. In this case prevent the link count from going to zero | |
868 | * prematurely. | |
869 | */ | |
870 | if (inode->i_nlink > !!alias) | |
871 | drop_nlink(inode); | |
872 | } | |
873 | ||
e9be9d5e MS |
874 | static int ovl_do_remove(struct dentry *dentry, bool is_dir) |
875 | { | |
e9be9d5e | 876 | int err; |
1175b6b8 | 877 | const struct cred *old_cred; |
d9854c87 | 878 | struct dentry *upperdentry; |
6d0a8a90 AG |
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); | |
885 | if (err) | |
886 | goto out; | |
887 | } | |
1175b6b8 | 888 | |
e9be9d5e MS |
889 | err = ovl_want_write(dentry); |
890 | if (err) | |
891 | goto out; | |
892 | ||
893 | err = ovl_copy_up(dentry->d_parent); | |
894 | if (err) | |
895 | goto out_drop_write; | |
896 | ||
0e32992f | 897 | err = ovl_nlink_start(dentry); |
5f8415d6 AG |
898 | if (err) |
899 | goto out_drop_write; | |
e9be9d5e | 900 | |
1175b6b8 | 901 | old_cred = ovl_override_creds(dentry->d_sb); |
6d0a8a90 AG |
902 | if (!lower_positive) |
903 | err = ovl_remove_upper(dentry, is_dir, &list); | |
1175b6b8 | 904 | else |
6d0a8a90 | 905 | err = ovl_remove_and_whiteout(dentry, &list); |
1175b6b8 | 906 | revert_creds(old_cred); |
dbc816d0 MS |
907 | if (!err) { |
908 | if (is_dir) | |
909 | clear_nlink(dentry->d_inode); | |
910 | else | |
83552eac | 911 | ovl_drop_nlink(dentry); |
dbc816d0 | 912 | } |
0e32992f | 913 | ovl_nlink_end(dentry); |
d9854c87 MS |
914 | |
915 | /* | |
916 | * Copy ctime | |
917 | * | |
918 | * Note: we fail to update ctime if there was no copy-up, only a | |
919 | * whiteout | |
920 | */ | |
921 | upperdentry = ovl_dentry_upper(dentry); | |
922 | if (upperdentry) | |
923 | ovl_copyattr(d_inode(upperdentry), d_inode(dentry)); | |
924 | ||
e9be9d5e MS |
925 | out_drop_write: |
926 | ovl_drop_write(dentry); | |
927 | out: | |
6d0a8a90 | 928 | ovl_cache_free(&list); |
e9be9d5e MS |
929 | return err; |
930 | } | |
931 | ||
932 | static int ovl_unlink(struct inode *dir, struct dentry *dentry) | |
933 | { | |
934 | return ovl_do_remove(dentry, false); | |
935 | } | |
936 | ||
937 | static int ovl_rmdir(struct inode *dir, struct dentry *dentry) | |
938 | { | |
939 | return ovl_do_remove(dentry, true); | |
940 | } | |
941 | ||
370e55ac MS |
942 | static bool ovl_type_merge_or_lower(struct dentry *dentry) |
943 | { | |
944 | enum ovl_path_type type = ovl_path_type(dentry); | |
945 | ||
946 | return OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type); | |
947 | } | |
948 | ||
a6c60655 MS |
949 | static bool ovl_can_move(struct dentry *dentry) |
950 | { | |
951 | return ovl_redirect_dir(dentry->d_sb) || | |
952 | !d_is_dir(dentry) || !ovl_type_merge_or_lower(dentry); | |
953 | } | |
954 | ||
7bb08383 | 955 | static char *ovl_get_redirect(struct dentry *dentry, bool abs_redirect) |
a6c60655 MS |
956 | { |
957 | char *buf, *ret; | |
958 | struct dentry *d, *tmp; | |
3ea22a71 | 959 | int buflen = ovl_redirect_max + 1; |
a6c60655 | 960 | |
7bb08383 | 961 | if (!abs_redirect) { |
a6c60655 MS |
962 | ret = kstrndup(dentry->d_name.name, dentry->d_name.len, |
963 | GFP_KERNEL); | |
964 | goto out; | |
965 | } | |
966 | ||
0ee931c4 | 967 | buf = ret = kmalloc(buflen, GFP_KERNEL); |
a6c60655 MS |
968 | if (!buf) |
969 | goto out; | |
970 | ||
971 | buflen--; | |
972 | buf[buflen] = '\0'; | |
973 | for (d = dget(dentry); !IS_ROOT(d);) { | |
974 | const char *name; | |
975 | int thislen; | |
976 | ||
977 | spin_lock(&d->d_lock); | |
978 | name = ovl_dentry_get_redirect(d); | |
979 | if (name) { | |
980 | thislen = strlen(name); | |
981 | } else { | |
982 | name = d->d_name.name; | |
983 | thislen = d->d_name.len; | |
984 | } | |
985 | ||
986 | /* If path is too long, fall back to userspace move */ | |
987 | if (thislen + (name[0] != '/') > buflen) { | |
988 | ret = ERR_PTR(-EXDEV); | |
989 | spin_unlock(&d->d_lock); | |
990 | goto out_put; | |
991 | } | |
992 | ||
993 | buflen -= thislen; | |
994 | memcpy(&buf[buflen], name, thislen); | |
995 | tmp = dget_dlock(d->d_parent); | |
996 | spin_unlock(&d->d_lock); | |
997 | ||
998 | dput(d); | |
999 | d = tmp; | |
1000 | ||
1001 | /* Absolute redirect: finished */ | |
1002 | if (buf[buflen] == '/') | |
1003 | break; | |
1004 | buflen--; | |
1005 | buf[buflen] = '/'; | |
1006 | } | |
1007 | ret = kstrdup(&buf[buflen], GFP_KERNEL); | |
1008 | out_put: | |
1009 | dput(d); | |
1010 | kfree(buf); | |
1011 | out: | |
1012 | return ret ? ret : ERR_PTR(-ENOMEM); | |
1013 | } | |
1014 | ||
7bb08383 VG |
1015 | static bool ovl_need_absolute_redirect(struct dentry *dentry, bool samedir) |
1016 | { | |
1017 | struct dentry *lowerdentry; | |
1018 | ||
1019 | if (!samedir) | |
1020 | return true; | |
1021 | ||
1022 | if (d_is_dir(dentry)) | |
1023 | return false; | |
1024 | ||
1025 | /* | |
1026 | * For non-dir hardlinked files, we need absolute redirects | |
1027 | * in general as two upper hardlinks could be in different | |
1028 | * dirs. We could put a relative redirect now and convert | |
1029 | * it to absolute redirect later. But when nlink > 1 and | |
1030 | * indexing is on, that means relative redirect needs to be | |
1031 | * converted to absolute during copy up of another lower | |
1032 | * hardllink as well. | |
1033 | * | |
1034 | * So without optimizing too much, just check if lower is | |
1035 | * a hard link or not. If lower is hard link, put absolute | |
1036 | * redirect. | |
1037 | */ | |
1038 | lowerdentry = ovl_dentry_lower(dentry); | |
1039 | return (d_inode(lowerdentry)->i_nlink > 1); | |
1040 | } | |
1041 | ||
a6c60655 MS |
1042 | static int ovl_set_redirect(struct dentry *dentry, bool samedir) |
1043 | { | |
1044 | int err; | |
1045 | const char *redirect = ovl_dentry_get_redirect(dentry); | |
7bb08383 | 1046 | bool absolute_redirect = ovl_need_absolute_redirect(dentry, samedir); |
a6c60655 | 1047 | |
7bb08383 | 1048 | if (redirect && (!absolute_redirect || redirect[0] == '/')) |
a6c60655 MS |
1049 | return 0; |
1050 | ||
7bb08383 | 1051 | redirect = ovl_get_redirect(dentry, absolute_redirect); |
a6c60655 MS |
1052 | if (IS_ERR(redirect)) |
1053 | return PTR_ERR(redirect); | |
1054 | ||
21a22878 AG |
1055 | err = ovl_check_setxattr(dentry, ovl_dentry_upper(dentry), |
1056 | OVL_XATTR_REDIRECT, | |
1057 | redirect, strlen(redirect), -EXDEV); | |
a6c60655 MS |
1058 | if (!err) { |
1059 | spin_lock(&dentry->d_lock); | |
1060 | ovl_dentry_set_redirect(dentry, redirect); | |
1061 | spin_unlock(&dentry->d_lock); | |
1062 | } else { | |
1063 | kfree(redirect); | |
1bd0a3ae | 1064 | pr_warn_ratelimited("failed to set redirect (%i)\n", |
da2e6b7e | 1065 | err); |
a6c60655 MS |
1066 | /* Fall back to userspace copy-up */ |
1067 | err = -EXDEV; | |
1068 | } | |
1069 | return err; | |
1070 | } | |
1071 | ||
6c02cb59 MS |
1072 | static int ovl_rename(struct inode *olddir, struct dentry *old, |
1073 | struct inode *newdir, struct dentry *new, | |
1074 | unsigned int flags) | |
e9be9d5e MS |
1075 | { |
1076 | int err; | |
e9be9d5e MS |
1077 | struct dentry *old_upperdir; |
1078 | struct dentry *new_upperdir; | |
1079 | struct dentry *olddentry; | |
1080 | struct dentry *newdentry; | |
1081 | struct dentry *trap; | |
1082 | bool old_opaque; | |
1083 | bool new_opaque; | |
e9be9d5e | 1084 | bool cleanup_whiteout = false; |
0e32992f | 1085 | bool update_nlink = false; |
e9be9d5e | 1086 | bool overwrite = !(flags & RENAME_EXCHANGE); |
e36cb0b8 | 1087 | bool is_dir = d_is_dir(old); |
370e55ac | 1088 | bool new_is_dir = d_is_dir(new); |
a6c60655 | 1089 | bool samedir = olddir == newdir; |
e9be9d5e MS |
1090 | struct dentry *opaquedir = NULL; |
1091 | const struct cred *old_cred = NULL; | |
6d0a8a90 | 1092 | LIST_HEAD(list); |
e9be9d5e MS |
1093 | |
1094 | err = -EINVAL; | |
1095 | if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) | |
1096 | goto out; | |
1097 | ||
1098 | flags &= ~RENAME_NOREPLACE; | |
1099 | ||
e9be9d5e | 1100 | /* Don't copy up directory trees */ |
e9be9d5e | 1101 | err = -EXDEV; |
a6c60655 | 1102 | if (!ovl_can_move(old)) |
370e55ac | 1103 | goto out; |
a6c60655 | 1104 | if (!overwrite && !ovl_can_move(new)) |
e9be9d5e | 1105 | goto out; |
e9be9d5e | 1106 | |
6d0a8a90 AG |
1107 | if (overwrite && new_is_dir && !ovl_pure_upper(new)) { |
1108 | err = ovl_check_empty_dir(new, &list); | |
1109 | if (err) | |
1110 | goto out; | |
1111 | } | |
1112 | ||
1113 | if (overwrite) { | |
1114 | if (ovl_lower_positive(old)) { | |
1115 | if (!ovl_dentry_is_whiteout(new)) { | |
1116 | /* Whiteout source */ | |
1117 | flags |= RENAME_WHITEOUT; | |
1118 | } else { | |
1119 | /* Switch whiteouts */ | |
1120 | flags |= RENAME_EXCHANGE; | |
1121 | } | |
1122 | } else if (is_dir && ovl_dentry_is_whiteout(new)) { | |
1123 | flags |= RENAME_EXCHANGE; | |
1124 | cleanup_whiteout = true; | |
1125 | } | |
1126 | } | |
1127 | ||
e9be9d5e MS |
1128 | err = ovl_want_write(old); |
1129 | if (err) | |
1130 | goto out; | |
1131 | ||
1132 | err = ovl_copy_up(old); | |
1133 | if (err) | |
1134 | goto out_drop_write; | |
1135 | ||
1136 | err = ovl_copy_up(new->d_parent); | |
1137 | if (err) | |
1138 | goto out_drop_write; | |
1139 | if (!overwrite) { | |
1140 | err = ovl_copy_up(new); | |
1141 | if (err) | |
1142 | goto out_drop_write; | |
0e32992f AG |
1143 | } else if (d_inode(new)) { |
1144 | err = ovl_nlink_start(new); | |
5f8415d6 AG |
1145 | if (err) |
1146 | goto out_drop_write; | |
0e32992f AG |
1147 | |
1148 | update_nlink = true; | |
e9be9d5e MS |
1149 | } |
1150 | ||
1175b6b8 | 1151 | old_cred = ovl_override_creds(old->d_sb); |
e9be9d5e | 1152 | |
6d0a8a90 AG |
1153 | if (!list_empty(&list)) { |
1154 | opaquedir = ovl_clear_empty(new, &list); | |
e9be9d5e MS |
1155 | err = PTR_ERR(opaquedir); |
1156 | if (IS_ERR(opaquedir)) { | |
1157 | opaquedir = NULL; | |
1158 | goto out_revert_creds; | |
1159 | } | |
1160 | } | |
1161 | ||
e9be9d5e MS |
1162 | old_upperdir = ovl_dentry_upper(old->d_parent); |
1163 | new_upperdir = ovl_dentry_upper(new->d_parent); | |
1164 | ||
ee1d6d37 AG |
1165 | if (!samedir) { |
1166 | /* | |
1167 | * When moving a merge dir or non-dir with copy up origin into | |
f3a15685 AG |
1168 | * a new parent, we are marking the new parent dir "impure". |
1169 | * When ovl_iterate() iterates an "impure" upper dir, it will | |
1170 | * lookup the origin inodes of the entries to fill d_ino. | |
ee1d6d37 | 1171 | */ |
f3a15685 | 1172 | if (ovl_type_origin(old)) { |
ee1d6d37 AG |
1173 | err = ovl_set_impure(new->d_parent, new_upperdir); |
1174 | if (err) | |
1175 | goto out_revert_creds; | |
1176 | } | |
f3a15685 | 1177 | if (!overwrite && ovl_type_origin(new)) { |
ee1d6d37 AG |
1178 | err = ovl_set_impure(old->d_parent, old_upperdir); |
1179 | if (err) | |
1180 | goto out_revert_creds; | |
1181 | } | |
1182 | } | |
1183 | ||
e9be9d5e MS |
1184 | trap = lock_rename(new_upperdir, old_upperdir); |
1185 | ||
11f37104 MS |
1186 | olddentry = lookup_one_len(old->d_name.name, old_upperdir, |
1187 | old->d_name.len); | |
1188 | err = PTR_ERR(olddentry); | |
1189 | if (IS_ERR(olddentry)) | |
1190 | goto out_unlock; | |
1191 | ||
1192 | err = -ESTALE; | |
9020df37 | 1193 | if (!ovl_matches_upper(old, olddentry)) |
11f37104 MS |
1194 | goto out_dput_old; |
1195 | ||
1196 | newdentry = lookup_one_len(new->d_name.name, new_upperdir, | |
1197 | new->d_name.len); | |
1198 | err = PTR_ERR(newdentry); | |
1199 | if (IS_ERR(newdentry)) | |
1200 | goto out_dput_old; | |
1201 | ||
3ee23ff1 MS |
1202 | old_opaque = ovl_dentry_is_opaque(old); |
1203 | new_opaque = ovl_dentry_is_opaque(new); | |
1204 | ||
11f37104 | 1205 | err = -ESTALE; |
09d8b586 | 1206 | if (d_inode(new) && ovl_dentry_upper(new)) { |
e9be9d5e | 1207 | if (opaquedir) { |
11f37104 MS |
1208 | if (newdentry != opaquedir) |
1209 | goto out_dput; | |
e9be9d5e | 1210 | } else { |
9020df37 | 1211 | if (!ovl_matches_upper(new, newdentry)) |
11f37104 | 1212 | goto out_dput; |
e9be9d5e MS |
1213 | } |
1214 | } else { | |
11f37104 MS |
1215 | if (!d_is_negative(newdentry) && |
1216 | (!new_opaque || !ovl_is_whiteout(newdentry))) | |
1217 | goto out_dput; | |
e9be9d5e MS |
1218 | } |
1219 | ||
e9be9d5e MS |
1220 | if (olddentry == trap) |
1221 | goto out_dput; | |
1222 | if (newdentry == trap) | |
1223 | goto out_dput; | |
1224 | ||
6889ee5a | 1225 | if (olddentry->d_inode == newdentry->d_inode) |
804032fa MS |
1226 | goto out_dput; |
1227 | ||
5cf5b477 | 1228 | err = 0; |
7bb08383 VG |
1229 | if (ovl_type_merge_or_lower(old)) |
1230 | err = ovl_set_redirect(old, samedir); | |
1231 | else if (is_dir && !old_opaque && ovl_type_merge(new->d_parent)) | |
1232 | err = ovl_set_opaque_xerr(old, olddentry, -EXDEV); | |
1233 | if (err) | |
1234 | goto out_dput; | |
1235 | ||
1236 | if (!overwrite && ovl_type_merge_or_lower(new)) | |
1237 | err = ovl_set_redirect(new, samedir); | |
1238 | else if (!overwrite && new_is_dir && !new_opaque && | |
1239 | ovl_type_merge(old->d_parent)) | |
1240 | err = ovl_set_opaque_xerr(new, newdentry, -EXDEV); | |
1241 | if (err) | |
1242 | goto out_dput; | |
e9be9d5e | 1243 | |
3ee23ff1 MS |
1244 | err = ovl_do_rename(old_upperdir->d_inode, olddentry, |
1245 | new_upperdir->d_inode, newdentry, flags); | |
1246 | if (err) | |
e9be9d5e | 1247 | goto out_dput; |
e9be9d5e MS |
1248 | |
1249 | if (cleanup_whiteout) | |
1250 | ovl_cleanup(old_upperdir->d_inode, newdentry); | |
1251 | ||
f681eb1d AG |
1252 | if (overwrite && d_inode(new)) { |
1253 | if (new_is_dir) | |
1254 | clear_nlink(d_inode(new)); | |
1255 | else | |
83552eac | 1256 | ovl_drop_nlink(new); |
f681eb1d AG |
1257 | } |
1258 | ||
d9854c87 MS |
1259 | ovl_dir_modified(old->d_parent, ovl_type_origin(old) || |
1260 | (!overwrite && ovl_type_origin(new))); | |
1261 | ovl_dir_modified(new->d_parent, ovl_type_origin(old) || | |
1262 | (d_inode(new) && ovl_type_origin(new))); | |
1263 | ||
1264 | /* copy ctime: */ | |
1265 | ovl_copyattr(d_inode(olddentry), d_inode(old)); | |
1266 | if (d_inode(new) && ovl_dentry_upper(new)) | |
1267 | ovl_copyattr(d_inode(newdentry), d_inode(new)); | |
e9be9d5e MS |
1268 | |
1269 | out_dput: | |
1270 | dput(newdentry); | |
11f37104 MS |
1271 | out_dput_old: |
1272 | dput(olddentry); | |
e9be9d5e MS |
1273 | out_unlock: |
1274 | unlock_rename(new_upperdir, old_upperdir); | |
1275 | out_revert_creds: | |
1175b6b8 | 1276 | revert_creds(old_cred); |
0e32992f AG |
1277 | if (update_nlink) |
1278 | ovl_nlink_end(new); | |
e9be9d5e MS |
1279 | out_drop_write: |
1280 | ovl_drop_write(old); | |
1281 | out: | |
1282 | dput(opaquedir); | |
6d0a8a90 | 1283 | ovl_cache_free(&list); |
e9be9d5e MS |
1284 | return err; |
1285 | } | |
1286 | ||
1287 | const struct inode_operations ovl_dir_inode_operations = { | |
1288 | .lookup = ovl_lookup, | |
1289 | .mkdir = ovl_mkdir, | |
1290 | .symlink = ovl_symlink, | |
1291 | .unlink = ovl_unlink, | |
1292 | .rmdir = ovl_rmdir, | |
6c02cb59 | 1293 | .rename = ovl_rename, |
e9be9d5e MS |
1294 | .link = ovl_link, |
1295 | .setattr = ovl_setattr, | |
1296 | .create = ovl_create, | |
1297 | .mknod = ovl_mknod, | |
1298 | .permission = ovl_permission, | |
5b712091 | 1299 | .getattr = ovl_getattr, |
e9be9d5e | 1300 | .listxattr = ovl_listxattr, |
39a25b2b | 1301 | .get_acl = ovl_get_acl, |
d719e8f2 | 1302 | .update_time = ovl_update_time, |
e9be9d5e | 1303 | }; |