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 | ||
576bb263 | 26 | int ovl_cleanup(struct ovl_fs *ofs, struct inode *wdir, struct dentry *wdentry) |
e9be9d5e MS |
27 | { |
28 | int err; | |
29 | ||
30 | dget(wdentry); | |
e36cb0b8 | 31 | if (d_is_dir(wdentry)) |
576bb263 | 32 | err = ovl_do_rmdir(ofs, wdir, wdentry); |
e9be9d5e | 33 | else |
576bb263 | 34 | err = ovl_do_unlink(ofs, wdir, wdentry); |
e9be9d5e MS |
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 | ||
576bb263 | 45 | struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, 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 | 53 | |
22f289ce | 54 | temp = ovl_lookup_upper(ofs, name, workdir, strlen(name)); |
e9be9d5e | 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 | 72 | if (!ofs->whiteout) { |
576bb263 | 73 | whiteout = ovl_lookup_temp(ofs, workdir); |
c21c839b CX |
74 | if (IS_ERR(whiteout)) |
75 | goto out; | |
e9be9d5e | 76 | |
576bb263 | 77 | err = ovl_do_whiteout(ofs, wdir, whiteout); |
c21c839b CX |
78 | if (err) { |
79 | dput(whiteout); | |
80 | whiteout = ERR_PTR(err); | |
81 | goto out; | |
82 | } | |
83 | ofs->whiteout = whiteout; | |
e9be9d5e MS |
84 | } |
85 | ||
c21c839b | 86 | if (ofs->share_whiteout) { |
576bb263 | 87 | whiteout = ovl_lookup_temp(ofs, workdir); |
c21c839b CX |
88 | if (IS_ERR(whiteout)) |
89 | goto out; | |
90 | ||
576bb263 | 91 | err = ovl_do_link(ofs, ofs->whiteout, wdir, whiteout); |
c21c839b CX |
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 | ||
576bb263 | 125 | err = ovl_do_rename(ofs, wdir, whiteout, dir, dentry, flags); |
e7dd0e71 AG |
126 | if (err) |
127 | goto kill_whiteout; | |
128 | if (flags) | |
576bb263 | 129 | ovl_cleanup(ofs, wdir, dentry); |
e7dd0e71 AG |
130 | |
131 | out: | |
132 | dput(whiteout); | |
133 | return err; | |
134 | ||
135 | kill_whiteout: | |
576bb263 | 136 | ovl_cleanup(ofs, wdir, whiteout); |
e7dd0e71 AG |
137 | goto out; |
138 | } | |
139 | ||
576bb263 CB |
140 | int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, |
141 | struct dentry **newdentry, umode_t mode) | |
f73cc77c AV |
142 | { |
143 | int err; | |
144 | struct dentry *d, *dentry = *newdentry; | |
145 | ||
576bb263 | 146 | err = ovl_do_mkdir(ofs, dir, dentry, mode); |
f73cc77c AV |
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 | */ | |
22f289ce CB |
158 | d = ovl_lookup_upper(ofs, dentry->d_name.name, dentry->d_parent, |
159 | dentry->d_name.len); | |
f73cc77c | 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 | ||
576bb263 CB |
171 | struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir, |
172 | struct dentry *newdentry, 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 | 183 | if (attr->hardlink) { |
576bb263 | 184 | err = ovl_do_link(ofs, attr->hardlink, dir, newdentry); |
e9be9d5e | 185 | } else { |
32a3d848 | 186 | switch (attr->mode & S_IFMT) { |
e9be9d5e | 187 | case S_IFREG: |
576bb263 | 188 | err = ovl_do_create(ofs, dir, newdentry, attr->mode); |
e9be9d5e MS |
189 | break; |
190 | ||
191 | case S_IFDIR: | |
f73cc77c | 192 | /* mkdir is special... */ |
576bb263 | 193 | err = ovl_mkdir_real(ofs, 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: | |
576bb263 | 200 | err = ovl_do_mknod(ofs, dir, newdentry, attr->mode, |
6cf00764 | 201 | attr->rdev); |
e9be9d5e MS |
202 | break; |
203 | ||
204 | case S_IFLNK: | |
576bb263 | 205 | err = ovl_do_symlink(ofs, 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 | ||
576bb263 CB |
227 | struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, |
228 | struct ovl_cattr *attr) | |
137ec526 | 229 | { |
576bb263 CB |
230 | return ovl_create_real(ofs, d_inode(workdir), |
231 | ovl_lookup_temp(ofs, workdir), attr); | |
137ec526 AG |
232 | } |
233 | ||
21a22878 AG |
234 | static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper, |
235 | int xerr) | |
e9be9d5e | 236 | { |
a0c236b1 | 237 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
5cf5b477 MS |
238 | int err; |
239 | ||
a0c236b1 | 240 | err = ovl_check_setxattr(ofs, upper, OVL_XATTR_OPAQUE, "y", 1, xerr); |
5cf5b477 MS |
241 | if (!err) |
242 | ovl_dentry_set_opaque(dentry); | |
243 | ||
244 | return err; | |
e9be9d5e MS |
245 | } |
246 | ||
21a22878 AG |
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, upperdentry, -EIO); | |
255 | } | |
256 | ||
01b39dcc AG |
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) | |
72e48481 | 264 | { |
01b39dcc AG |
265 | struct ovl_inode_params oip = { |
266 | .upperdentry = newdentry, | |
267 | .newinode = inode, | |
268 | }; | |
269 | ||
d9854c87 | 270 | ovl_dir_modified(dentry->d_parent, false); |
55acc661 | 271 | ovl_dentry_set_upper_alias(dentry); |
f4288844 MS |
272 | ovl_dentry_update_reval(dentry, newdentry, |
273 | DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); | |
274 | ||
51f7e52d | 275 | if (!hardlink) { |
01b39dcc AG |
276 | /* |
277 | * ovl_obtain_alias() can be called after ovl_create_real() | |
278 | * and before we get here, so we may get an inode from cache | |
279 | * with the same real upperdentry that is not the inode we | |
280 | * pre-allocated. In this case we will use the cached inode | |
281 | * to instantiate the new dentry. | |
282 | * | |
283 | * XXX: if we ever use ovl_obtain_alias() to decode directory | |
284 | * file handles, need to use ovl_get_inode_locked() and | |
285 | * d_instantiate_new() here to prevent from creating two | |
286 | * hashed directory inode aliases. | |
287 | */ | |
288 | inode = ovl_get_inode(dentry->d_sb, &oip); | |
acf3062a | 289 | if (IS_ERR(inode)) |
01b39dcc | 290 | return PTR_ERR(inode); |
28166ab3 VG |
291 | if (inode == oip.newinode) |
292 | ovl_set_flag(OVL_UPPERDATA, inode); | |
51f7e52d | 293 | } else { |
09d8b586 MS |
294 | WARN_ON(ovl_inode_real(inode) != d_inode(newdentry)); |
295 | dput(newdentry); | |
51f7e52d MS |
296 | inc_nlink(inode); |
297 | } | |
01b39dcc | 298 | |
72e48481 | 299 | d_instantiate(dentry, inode); |
01b39dcc | 300 | if (inode != oip.newinode) { |
1bd0a3ae | 301 | pr_warn_ratelimited("newly created inode found in cache (%pd2)\n", |
01b39dcc AG |
302 | dentry); |
303 | } | |
304 | ||
5b6c9053 AG |
305 | /* Force lookup of new upper hardlink to find its lower */ |
306 | if (hardlink) | |
307 | d_drop(dentry); | |
01b39dcc AG |
308 | |
309 | return 0; | |
72e48481 VG |
310 | } |
311 | ||
97c684cc AG |
312 | static bool ovl_type_merge(struct dentry *dentry) |
313 | { | |
314 | return OVL_TYPE_MERGE(ovl_path_type(dentry)); | |
315 | } | |
316 | ||
ee1d6d37 AG |
317 | static bool ovl_type_origin(struct dentry *dentry) |
318 | { | |
319 | return OVL_TYPE_ORIGIN(ovl_path_type(dentry)); | |
320 | } | |
321 | ||
e9be9d5e | 322 | static int ovl_create_upper(struct dentry *dentry, struct inode *inode, |
471ec5dc | 323 | struct ovl_cattr *attr) |
e9be9d5e | 324 | { |
1fc31aac | 325 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e MS |
326 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); |
327 | struct inode *udir = upperdir->d_inode; | |
328 | struct dentry *newdentry; | |
329 | int err; | |
330 | ||
471ec5dc | 331 | if (!attr->hardlink && !IS_POSIXACL(udir)) |
32a3d848 | 332 | attr->mode &= ~current_umask(); |
38b25697 | 333 | |
5955102c | 334 | inode_lock_nested(udir, I_MUTEX_PARENT); |
576bb263 | 335 | newdentry = ovl_create_real(ofs, udir, |
22f289ce CB |
336 | ovl_lookup_upper(ofs, dentry->d_name.name, |
337 | upperdir, dentry->d_name.len), | |
95a1c815 | 338 | attr); |
e9be9d5e MS |
339 | err = PTR_ERR(newdentry); |
340 | if (IS_ERR(newdentry)) | |
341 | goto out_unlock; | |
e9be9d5e | 342 | |
1fc31aac VY |
343 | if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry) && |
344 | !ovl_allow_offline_changes(ofs)) { | |
97c684cc AG |
345 | /* Setting opaque here is just an optimization, allow to fail */ |
346 | ovl_set_opaque(dentry, newdentry); | |
347 | } | |
348 | ||
01b39dcc AG |
349 | err = ovl_instantiate(dentry, inode, newdentry, !!attr->hardlink); |
350 | if (err) | |
351 | goto out_cleanup; | |
e9be9d5e | 352 | out_unlock: |
5955102c | 353 | inode_unlock(udir); |
e9be9d5e | 354 | return err; |
01b39dcc AG |
355 | |
356 | out_cleanup: | |
576bb263 | 357 | ovl_cleanup(ofs, udir, newdentry); |
01b39dcc AG |
358 | dput(newdentry); |
359 | goto out_unlock; | |
e9be9d5e MS |
360 | } |
361 | ||
e9be9d5e MS |
362 | static struct dentry *ovl_clear_empty(struct dentry *dentry, |
363 | struct list_head *list) | |
364 | { | |
576bb263 | 365 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e MS |
366 | struct dentry *workdir = ovl_workdir(dentry); |
367 | struct inode *wdir = workdir->d_inode; | |
368 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
369 | struct inode *udir = upperdir->d_inode; | |
370 | struct path upperpath; | |
371 | struct dentry *upper; | |
372 | struct dentry *opaquedir; | |
373 | struct kstat stat; | |
374 | int err; | |
375 | ||
cc6f67bc MS |
376 | if (WARN_ON(!workdir)) |
377 | return ERR_PTR(-EROFS); | |
378 | ||
e9be9d5e MS |
379 | err = ovl_lock_rename_workdir(workdir, upperdir); |
380 | if (err) | |
381 | goto out; | |
382 | ||
383 | ovl_path_upper(dentry, &upperpath); | |
a528d35e DH |
384 | err = vfs_getattr(&upperpath, &stat, |
385 | STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); | |
e9be9d5e MS |
386 | if (err) |
387 | goto out_unlock; | |
388 | ||
389 | err = -ESTALE; | |
390 | if (!S_ISDIR(stat.mode)) | |
391 | goto out_unlock; | |
392 | upper = upperpath.dentry; | |
393 | if (upper->d_parent->d_inode != udir) | |
394 | goto out_unlock; | |
395 | ||
576bb263 | 396 | opaquedir = ovl_create_temp(ofs, workdir, OVL_CATTR(stat.mode)); |
e9be9d5e MS |
397 | err = PTR_ERR(opaquedir); |
398 | if (IS_ERR(opaquedir)) | |
399 | goto out_unlock; | |
400 | ||
dad7017a | 401 | err = ovl_copy_xattr(dentry->d_sb, &upperpath, opaquedir); |
e9be9d5e MS |
402 | if (err) |
403 | goto out_cleanup; | |
404 | ||
5cf5b477 | 405 | err = ovl_set_opaque(dentry, opaquedir); |
e9be9d5e MS |
406 | if (err) |
407 | goto out_cleanup; | |
408 | ||
5955102c | 409 | inode_lock(opaquedir->d_inode); |
5272eaf3 | 410 | err = ovl_set_attr(ofs, opaquedir, &stat); |
5955102c | 411 | inode_unlock(opaquedir->d_inode); |
e9be9d5e MS |
412 | if (err) |
413 | goto out_cleanup; | |
414 | ||
576bb263 | 415 | err = ovl_do_rename(ofs, wdir, opaquedir, udir, upper, RENAME_EXCHANGE); |
e9be9d5e MS |
416 | if (err) |
417 | goto out_cleanup; | |
418 | ||
576bb263 CB |
419 | ovl_cleanup_whiteouts(ofs, upper, list); |
420 | ovl_cleanup(ofs, wdir, upper); | |
e9be9d5e MS |
421 | unlock_rename(workdir, upperdir); |
422 | ||
423 | /* dentry's upper doesn't match now, get rid of it */ | |
424 | d_drop(dentry); | |
425 | ||
426 | return opaquedir; | |
427 | ||
428 | out_cleanup: | |
576bb263 | 429 | ovl_cleanup(ofs, wdir, opaquedir); |
e9be9d5e MS |
430 | dput(opaquedir); |
431 | out_unlock: | |
432 | unlock_rename(workdir, upperdir); | |
433 | out: | |
434 | return ERR_PTR(err); | |
435 | } | |
436 | ||
c914c0e2 | 437 | static int ovl_set_upper_acl(struct ovl_fs *ofs, struct dentry *upperdentry, |
31acceb9 | 438 | const char *acl_name, struct posix_acl *acl) |
38b25697 | 439 | { |
38b25697 MS |
440 | if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl) |
441 | return 0; | |
442 | ||
31acceb9 | 443 | return ovl_do_set_acl(ofs, upperdentry, acl_name, acl); |
38b25697 MS |
444 | } |
445 | ||
e9be9d5e | 446 | static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, |
471ec5dc | 447 | struct ovl_cattr *cattr) |
e9be9d5e | 448 | { |
c914c0e2 | 449 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e MS |
450 | struct dentry *workdir = ovl_workdir(dentry); |
451 | struct inode *wdir = workdir->d_inode; | |
452 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); | |
453 | struct inode *udir = upperdir->d_inode; | |
454 | struct dentry *upper; | |
455 | struct dentry *newdentry; | |
456 | int err; | |
38b25697 | 457 | struct posix_acl *acl, *default_acl; |
471ec5dc | 458 | bool hardlink = !!cattr->hardlink; |
e9be9d5e | 459 | |
cc6f67bc MS |
460 | if (WARN_ON(!workdir)) |
461 | return -EROFS; | |
462 | ||
38b25697 MS |
463 | if (!hardlink) { |
464 | err = posix_acl_create(dentry->d_parent->d_inode, | |
32a3d848 | 465 | &cattr->mode, &default_acl, &acl); |
38b25697 MS |
466 | if (err) |
467 | return err; | |
468 | } | |
469 | ||
e9be9d5e MS |
470 | err = ovl_lock_rename_workdir(workdir, upperdir); |
471 | if (err) | |
472 | goto out; | |
473 | ||
22f289ce CB |
474 | upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir, |
475 | dentry->d_name.len); | |
e9be9d5e MS |
476 | err = PTR_ERR(upper); |
477 | if (IS_ERR(upper)) | |
95a1c815 | 478 | goto out_unlock; |
e9be9d5e | 479 | |
5e127580 MS |
480 | err = -ESTALE; |
481 | if (d_is_negative(upper) || !IS_WHITEOUT(d_inode(upper))) | |
482 | goto out_dput; | |
483 | ||
576bb263 | 484 | newdentry = ovl_create_temp(ofs, workdir, cattr); |
95a1c815 MS |
485 | err = PTR_ERR(newdentry); |
486 | if (IS_ERR(newdentry)) | |
487 | goto out_dput; | |
e9be9d5e | 488 | |
bb0d2b8a MS |
489 | /* |
490 | * mode could have been mutilated due to umask (e.g. sgid directory) | |
491 | */ | |
51f7e52d | 492 | if (!hardlink && |
32a3d848 AV |
493 | !S_ISLNK(cattr->mode) && |
494 | newdentry->d_inode->i_mode != cattr->mode) { | |
bb0d2b8a MS |
495 | struct iattr attr = { |
496 | .ia_valid = ATTR_MODE, | |
32a3d848 | 497 | .ia_mode = cattr->mode, |
bb0d2b8a MS |
498 | }; |
499 | inode_lock(newdentry->d_inode); | |
a15506ea | 500 | err = ovl_do_notify_change(ofs, newdentry, &attr); |
bb0d2b8a MS |
501 | inode_unlock(newdentry->d_inode); |
502 | if (err) | |
503 | goto out_cleanup; | |
504 | } | |
38b25697 | 505 | if (!hardlink) { |
c914c0e2 AG |
506 | err = ovl_set_upper_acl(ofs, newdentry, |
507 | XATTR_NAME_POSIX_ACL_ACCESS, acl); | |
38b25697 MS |
508 | if (err) |
509 | goto out_cleanup; | |
510 | ||
c914c0e2 AG |
511 | err = ovl_set_upper_acl(ofs, newdentry, |
512 | XATTR_NAME_POSIX_ACL_DEFAULT, default_acl); | |
38b25697 MS |
513 | if (err) |
514 | goto out_cleanup; | |
515 | } | |
bb0d2b8a | 516 | |
32a3d848 | 517 | if (!hardlink && S_ISDIR(cattr->mode)) { |
5cf5b477 | 518 | err = ovl_set_opaque(dentry, newdentry); |
e9be9d5e MS |
519 | if (err) |
520 | goto out_cleanup; | |
521 | ||
576bb263 | 522 | err = ovl_do_rename(ofs, wdir, newdentry, udir, upper, |
e9be9d5e MS |
523 | RENAME_EXCHANGE); |
524 | if (err) | |
525 | goto out_cleanup; | |
526 | ||
576bb263 | 527 | ovl_cleanup(ofs, wdir, upper); |
e9be9d5e | 528 | } else { |
576bb263 | 529 | err = ovl_do_rename(ofs, wdir, newdentry, udir, upper, 0); |
e9be9d5e MS |
530 | if (err) |
531 | goto out_cleanup; | |
532 | } | |
01b39dcc | 533 | err = ovl_instantiate(dentry, inode, newdentry, hardlink); |
52d5a0c6 | 534 | if (err) { |
576bb263 | 535 | ovl_cleanup(ofs, udir, newdentry); |
52d5a0c6 | 536 | dput(newdentry); |
537 | } | |
e9be9d5e | 538 | out_dput: |
95a1c815 | 539 | dput(upper); |
e9be9d5e MS |
540 | out_unlock: |
541 | unlock_rename(workdir, upperdir); | |
542 | out: | |
38b25697 MS |
543 | if (!hardlink) { |
544 | posix_acl_release(acl); | |
545 | posix_acl_release(default_acl); | |
546 | } | |
e9be9d5e MS |
547 | return err; |
548 | ||
549 | out_cleanup: | |
576bb263 | 550 | ovl_cleanup(ofs, wdir, newdentry); |
95a1c815 MS |
551 | dput(newdentry); |
552 | goto out_dput; | |
e9be9d5e MS |
553 | } |
554 | ||
51f7e52d | 555 | static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, |
471ec5dc | 556 | struct ovl_cattr *attr, bool origin) |
e9be9d5e MS |
557 | { |
558 | int err; | |
1175b6b8 VG |
559 | const struct cred *old_cred; |
560 | struct cred *override_cred; | |
ea3dad18 | 561 | struct dentry *parent = dentry->d_parent; |
e9be9d5e | 562 | |
ea3dad18 | 563 | err = ovl_copy_up(parent); |
e9be9d5e | 564 | if (err) |
51f7e52d | 565 | return err; |
bb0d2b8a | 566 | |
1175b6b8 | 567 | old_cred = ovl_override_creds(dentry->d_sb); |
ea3dad18 AG |
568 | |
569 | /* | |
570 | * When linking a file with copy up origin into a new parent, mark the | |
571 | * new parent dir "impure". | |
572 | */ | |
573 | if (origin) { | |
574 | err = ovl_set_impure(parent, ovl_dentry_upper(parent)); | |
575 | if (err) | |
576 | goto out_revert_creds; | |
577 | } | |
578 | ||
1175b6b8 VG |
579 | err = -ENOMEM; |
580 | override_cred = prepare_creds(); | |
581 | if (override_cred) { | |
bb0d2b8a MS |
582 | override_cred->fsuid = inode->i_uid; |
583 | override_cred->fsgid = inode->i_gid; | |
471ec5dc | 584 | if (!attr->hardlink) { |
2602625b | 585 | err = security_dentry_create_files_as(dentry, |
32a3d848 | 586 | attr->mode, &dentry->d_name, old_cred, |
2602625b VG |
587 | override_cred); |
588 | if (err) { | |
589 | put_cred(override_cred); | |
590 | goto out_revert_creds; | |
591 | } | |
592 | } | |
1175b6b8 VG |
593 | put_cred(override_creds(override_cred)); |
594 | put_cred(override_cred); | |
595 | ||
c412ce49 | 596 | if (!ovl_dentry_is_whiteout(dentry)) |
471ec5dc | 597 | err = ovl_create_upper(dentry, inode, attr); |
1175b6b8 | 598 | else |
471ec5dc | 599 | err = ovl_create_over_whiteout(dentry, inode, attr); |
e9be9d5e | 600 | } |
2602625b | 601 | out_revert_creds: |
1175b6b8 | 602 | revert_creds(old_cred); |
e9be9d5e MS |
603 | return err; |
604 | } | |
605 | ||
606 | static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, | |
607 | const char *link) | |
608 | { | |
609 | int err; | |
51f7e52d | 610 | struct inode *inode; |
471ec5dc | 611 | struct ovl_cattr attr = { |
51f7e52d | 612 | .rdev = rdev, |
32a3d848 | 613 | .link = link, |
51f7e52d | 614 | }; |
e9be9d5e MS |
615 | |
616 | err = ovl_want_write(dentry); | |
51f7e52d MS |
617 | if (err) |
618 | goto out; | |
619 | ||
01b39dcc | 620 | /* Preallocate inode to be used by ovl_get_inode() */ |
51f7e52d | 621 | err = -ENOMEM; |
ca4c8a3a | 622 | inode = ovl_new_inode(dentry->d_sb, mode, rdev); |
51f7e52d MS |
623 | if (!inode) |
624 | goto out_drop_write; | |
625 | ||
6faf05c2 MS |
626 | spin_lock(&inode->i_lock); |
627 | inode->i_state |= I_CREATING; | |
628 | spin_unlock(&inode->i_lock); | |
629 | ||
21cb47be | 630 | inode_init_owner(&init_user_ns, inode, dentry->d_parent->d_inode, mode); |
32a3d848 | 631 | attr.mode = inode->i_mode; |
51f7e52d | 632 | |
471ec5dc | 633 | err = ovl_create_or_link(dentry, inode, &attr, false); |
01b39dcc AG |
634 | /* Did we end up using the preallocated inode? */ |
635 | if (inode != d_inode(dentry)) | |
51f7e52d | 636 | iput(inode); |
e9be9d5e | 637 | |
51f7e52d MS |
638 | out_drop_write: |
639 | ovl_drop_write(dentry); | |
640 | out: | |
e9be9d5e MS |
641 | return err; |
642 | } | |
643 | ||
549c7297 CB |
644 | static int ovl_create(struct user_namespace *mnt_userns, struct inode *dir, |
645 | struct dentry *dentry, umode_t mode, bool excl) | |
e9be9d5e MS |
646 | { |
647 | return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL); | |
648 | } | |
649 | ||
549c7297 CB |
650 | static int ovl_mkdir(struct user_namespace *mnt_userns, struct inode *dir, |
651 | struct dentry *dentry, umode_t mode) | |
e9be9d5e MS |
652 | { |
653 | return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL); | |
654 | } | |
655 | ||
549c7297 CB |
656 | static int ovl_mknod(struct user_namespace *mnt_userns, struct inode *dir, |
657 | struct dentry *dentry, umode_t mode, dev_t rdev) | |
e9be9d5e MS |
658 | { |
659 | /* Don't allow creation of "whiteout" on overlay */ | |
660 | if (S_ISCHR(mode) && rdev == WHITEOUT_DEV) | |
661 | return -EPERM; | |
662 | ||
663 | return ovl_create_object(dentry, mode, rdev, NULL); | |
664 | } | |
665 | ||
549c7297 CB |
666 | static int ovl_symlink(struct user_namespace *mnt_userns, struct inode *dir, |
667 | struct dentry *dentry, const char *link) | |
e9be9d5e MS |
668 | { |
669 | return ovl_create_object(dentry, S_IFLNK, 0, link); | |
670 | } | |
671 | ||
91ff20f3 AG |
672 | static int ovl_set_link_redirect(struct dentry *dentry) |
673 | { | |
674 | const struct cred *old_cred; | |
675 | int err; | |
676 | ||
677 | old_cred = ovl_override_creds(dentry->d_sb); | |
678 | err = ovl_set_redirect(dentry, false); | |
679 | revert_creds(old_cred); | |
680 | ||
681 | return err; | |
682 | } | |
683 | ||
e9be9d5e MS |
684 | static int ovl_link(struct dentry *old, struct inode *newdir, |
685 | struct dentry *new) | |
686 | { | |
687 | int err; | |
51f7e52d | 688 | struct inode *inode; |
e9be9d5e MS |
689 | |
690 | err = ovl_want_write(old); | |
691 | if (err) | |
692 | goto out; | |
693 | ||
694 | err = ovl_copy_up(old); | |
695 | if (err) | |
696 | goto out_drop_write; | |
697 | ||
6cd07870 AG |
698 | err = ovl_copy_up(new->d_parent); |
699 | if (err) | |
700 | goto out_drop_write; | |
701 | ||
4120fe64 | 702 | if (ovl_is_metacopy_dentry(old)) { |
91ff20f3 | 703 | err = ovl_set_link_redirect(old); |
4120fe64 VG |
704 | if (err) |
705 | goto out_drop_write; | |
706 | } | |
707 | ||
0e32992f | 708 | err = ovl_nlink_start(old); |
5f8415d6 AG |
709 | if (err) |
710 | goto out_drop_write; | |
711 | ||
51f7e52d MS |
712 | inode = d_inode(old); |
713 | ihold(inode); | |
714 | ||
471ec5dc AG |
715 | err = ovl_create_or_link(new, inode, |
716 | &(struct ovl_cattr) {.hardlink = ovl_dentry_upper(old)}, | |
717 | ovl_type_origin(old)); | |
51f7e52d MS |
718 | if (err) |
719 | iput(inode); | |
e9be9d5e | 720 | |
0e32992f | 721 | ovl_nlink_end(old); |
e9be9d5e MS |
722 | out_drop_write: |
723 | ovl_drop_write(old); | |
724 | out: | |
725 | return err; | |
726 | } | |
727 | ||
9020df37 MS |
728 | static bool ovl_matches_upper(struct dentry *dentry, struct dentry *upper) |
729 | { | |
730 | return d_inode(ovl_dentry_upper(dentry)) == d_inode(upper); | |
731 | } | |
732 | ||
6d0a8a90 AG |
733 | static int ovl_remove_and_whiteout(struct dentry *dentry, |
734 | struct list_head *list) | |
e9be9d5e | 735 | { |
c21c839b | 736 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e | 737 | struct dentry *workdir = ovl_workdir(dentry); |
e9be9d5e | 738 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); |
e9be9d5e MS |
739 | struct dentry *upper; |
740 | struct dentry *opaquedir = NULL; | |
741 | int err; | |
742 | ||
cc6f67bc MS |
743 | if (WARN_ON(!workdir)) |
744 | return -EROFS; | |
745 | ||
6d0a8a90 AG |
746 | if (!list_empty(list)) { |
747 | opaquedir = ovl_clear_empty(dentry, list); | |
30c17ebf MS |
748 | err = PTR_ERR(opaquedir); |
749 | if (IS_ERR(opaquedir)) | |
750 | goto out; | |
e9be9d5e MS |
751 | } |
752 | ||
753 | err = ovl_lock_rename_workdir(workdir, upperdir); | |
754 | if (err) | |
755 | goto out_dput; | |
756 | ||
22f289ce CB |
757 | upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir, |
758 | dentry->d_name.len); | |
cfc9fde0 MP |
759 | err = PTR_ERR(upper); |
760 | if (IS_ERR(upper)) | |
e9be9d5e MS |
761 | goto out_unlock; |
762 | ||
cfc9fde0 MP |
763 | err = -ESTALE; |
764 | if ((opaquedir && upper != opaquedir) || | |
765 | (!opaquedir && ovl_dentry_upper(dentry) && | |
9020df37 | 766 | !ovl_matches_upper(dentry, upper))) { |
cfc9fde0 MP |
767 | goto out_dput_upper; |
768 | } | |
e9be9d5e | 769 | |
c21c839b | 770 | err = ovl_cleanup_and_whiteout(ofs, d_inode(upperdir), upper); |
cfc9fde0 | 771 | if (err) |
e7dd0e71 | 772 | goto out_d_drop; |
e9be9d5e | 773 | |
d9854c87 | 774 | ovl_dir_modified(dentry->d_parent, true); |
e9be9d5e MS |
775 | out_d_drop: |
776 | d_drop(dentry); | |
cfc9fde0 MP |
777 | out_dput_upper: |
778 | dput(upper); | |
e9be9d5e MS |
779 | out_unlock: |
780 | unlock_rename(workdir, upperdir); | |
781 | out_dput: | |
782 | dput(opaquedir); | |
783 | out: | |
784 | return err; | |
e9be9d5e MS |
785 | } |
786 | ||
6d0a8a90 AG |
787 | static int ovl_remove_upper(struct dentry *dentry, bool is_dir, |
788 | struct list_head *list) | |
e9be9d5e | 789 | { |
576bb263 | 790 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e MS |
791 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); |
792 | struct inode *dir = upperdir->d_inode; | |
11f37104 | 793 | struct dentry *upper; |
d1595119 | 794 | struct dentry *opaquedir = NULL; |
e9be9d5e MS |
795 | int err; |
796 | ||
6d0a8a90 AG |
797 | if (!list_empty(list)) { |
798 | opaquedir = ovl_clear_empty(dentry, list); | |
d1595119 AG |
799 | err = PTR_ERR(opaquedir); |
800 | if (IS_ERR(opaquedir)) | |
801 | goto out; | |
802 | } | |
803 | ||
5955102c | 804 | inode_lock_nested(dir, I_MUTEX_PARENT); |
22f289ce CB |
805 | upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir, |
806 | dentry->d_name.len); | |
11f37104 MS |
807 | err = PTR_ERR(upper); |
808 | if (IS_ERR(upper)) | |
809 | goto out_unlock; | |
810 | ||
e9be9d5e | 811 | err = -ESTALE; |
d1595119 | 812 | if ((opaquedir && upper != opaquedir) || |
9020df37 | 813 | (!opaquedir && !ovl_matches_upper(dentry, upper))) |
d1595119 AG |
814 | goto out_dput_upper; |
815 | ||
816 | if (is_dir) | |
576bb263 | 817 | err = ovl_do_rmdir(ofs, dir, upper); |
d1595119 | 818 | else |
576bb263 | 819 | err = ovl_do_unlink(ofs, dir, upper); |
d9854c87 | 820 | ovl_dir_modified(dentry->d_parent, ovl_type_origin(dentry)); |
e9be9d5e MS |
821 | |
822 | /* | |
823 | * Keeping this dentry hashed would mean having to release | |
824 | * upperpath/lowerpath, which could only be done if we are the | |
825 | * sole user of this dentry. Too tricky... Just unhash for | |
826 | * now. | |
827 | */ | |
ce9113bb RW |
828 | if (!err) |
829 | d_drop(dentry); | |
d1595119 AG |
830 | out_dput_upper: |
831 | dput(upper); | |
11f37104 | 832 | out_unlock: |
5955102c | 833 | inode_unlock(dir); |
d1595119 AG |
834 | dput(opaquedir); |
835 | out: | |
e9be9d5e MS |
836 | return err; |
837 | } | |
838 | ||
6d0a8a90 AG |
839 | static bool ovl_pure_upper(struct dentry *dentry) |
840 | { | |
841 | return !ovl_dentry_lower(dentry) && | |
842 | !ovl_test_flag(OVL_WHITEOUTS, d_inode(dentry)); | |
843 | } | |
844 | ||
83552eac MS |
845 | static void ovl_drop_nlink(struct dentry *dentry) |
846 | { | |
847 | struct inode *inode = d_inode(dentry); | |
848 | struct dentry *alias; | |
849 | ||
850 | /* Try to find another, hashed alias */ | |
851 | spin_lock(&inode->i_lock); | |
852 | hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { | |
853 | if (alias != dentry && !d_unhashed(alias)) | |
854 | break; | |
855 | } | |
856 | spin_unlock(&inode->i_lock); | |
857 | ||
858 | /* | |
859 | * Changes to underlying layers may cause i_nlink to lose sync with | |
860 | * reality. In this case prevent the link count from going to zero | |
861 | * prematurely. | |
862 | */ | |
863 | if (inode->i_nlink > !!alias) | |
864 | drop_nlink(inode); | |
865 | } | |
866 | ||
e9be9d5e MS |
867 | static int ovl_do_remove(struct dentry *dentry, bool is_dir) |
868 | { | |
e9be9d5e | 869 | int err; |
1175b6b8 | 870 | const struct cred *old_cred; |
6d0a8a90 AG |
871 | bool lower_positive = ovl_lower_positive(dentry); |
872 | LIST_HEAD(list); | |
873 | ||
874 | /* No need to clean pure upper removed by vfs_rmdir() */ | |
875 | if (is_dir && (lower_positive || !ovl_pure_upper(dentry))) { | |
876 | err = ovl_check_empty_dir(dentry, &list); | |
877 | if (err) | |
878 | goto out; | |
879 | } | |
1175b6b8 | 880 | |
e9be9d5e MS |
881 | err = ovl_want_write(dentry); |
882 | if (err) | |
883 | goto out; | |
884 | ||
885 | err = ovl_copy_up(dentry->d_parent); | |
886 | if (err) | |
887 | goto out_drop_write; | |
888 | ||
0e32992f | 889 | err = ovl_nlink_start(dentry); |
5f8415d6 AG |
890 | if (err) |
891 | goto out_drop_write; | |
e9be9d5e | 892 | |
1175b6b8 | 893 | old_cred = ovl_override_creds(dentry->d_sb); |
6d0a8a90 AG |
894 | if (!lower_positive) |
895 | err = ovl_remove_upper(dentry, is_dir, &list); | |
1175b6b8 | 896 | else |
6d0a8a90 | 897 | err = ovl_remove_and_whiteout(dentry, &list); |
1175b6b8 | 898 | revert_creds(old_cred); |
dbc816d0 MS |
899 | if (!err) { |
900 | if (is_dir) | |
901 | clear_nlink(dentry->d_inode); | |
902 | else | |
83552eac | 903 | ovl_drop_nlink(dentry); |
dbc816d0 | 904 | } |
0e32992f | 905 | ovl_nlink_end(dentry); |
d9854c87 MS |
906 | |
907 | /* | |
908 | * Copy ctime | |
909 | * | |
910 | * Note: we fail to update ctime if there was no copy-up, only a | |
911 | * whiteout | |
912 | */ | |
2878dffc CB |
913 | if (ovl_dentry_upper(dentry)) |
914 | ovl_copyattr(d_inode(dentry)); | |
d9854c87 | 915 | |
e9be9d5e MS |
916 | out_drop_write: |
917 | ovl_drop_write(dentry); | |
918 | out: | |
6d0a8a90 | 919 | ovl_cache_free(&list); |
e9be9d5e MS |
920 | return err; |
921 | } | |
922 | ||
923 | static int ovl_unlink(struct inode *dir, struct dentry *dentry) | |
924 | { | |
925 | return ovl_do_remove(dentry, false); | |
926 | } | |
927 | ||
928 | static int ovl_rmdir(struct inode *dir, struct dentry *dentry) | |
929 | { | |
930 | return ovl_do_remove(dentry, true); | |
931 | } | |
932 | ||
370e55ac MS |
933 | static bool ovl_type_merge_or_lower(struct dentry *dentry) |
934 | { | |
935 | enum ovl_path_type type = ovl_path_type(dentry); | |
936 | ||
937 | return OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type); | |
938 | } | |
939 | ||
a6c60655 MS |
940 | static bool ovl_can_move(struct dentry *dentry) |
941 | { | |
942 | return ovl_redirect_dir(dentry->d_sb) || | |
943 | !d_is_dir(dentry) || !ovl_type_merge_or_lower(dentry); | |
944 | } | |
945 | ||
7bb08383 | 946 | static char *ovl_get_redirect(struct dentry *dentry, bool abs_redirect) |
a6c60655 MS |
947 | { |
948 | char *buf, *ret; | |
949 | struct dentry *d, *tmp; | |
3ea22a71 | 950 | int buflen = ovl_redirect_max + 1; |
a6c60655 | 951 | |
7bb08383 | 952 | if (!abs_redirect) { |
a6c60655 MS |
953 | ret = kstrndup(dentry->d_name.name, dentry->d_name.len, |
954 | GFP_KERNEL); | |
955 | goto out; | |
956 | } | |
957 | ||
0ee931c4 | 958 | buf = ret = kmalloc(buflen, GFP_KERNEL); |
a6c60655 MS |
959 | if (!buf) |
960 | goto out; | |
961 | ||
962 | buflen--; | |
963 | buf[buflen] = '\0'; | |
964 | for (d = dget(dentry); !IS_ROOT(d);) { | |
965 | const char *name; | |
966 | int thislen; | |
967 | ||
968 | spin_lock(&d->d_lock); | |
969 | name = ovl_dentry_get_redirect(d); | |
970 | if (name) { | |
971 | thislen = strlen(name); | |
972 | } else { | |
973 | name = d->d_name.name; | |
974 | thislen = d->d_name.len; | |
975 | } | |
976 | ||
977 | /* If path is too long, fall back to userspace move */ | |
978 | if (thislen + (name[0] != '/') > buflen) { | |
979 | ret = ERR_PTR(-EXDEV); | |
980 | spin_unlock(&d->d_lock); | |
981 | goto out_put; | |
982 | } | |
983 | ||
984 | buflen -= thislen; | |
985 | memcpy(&buf[buflen], name, thislen); | |
a6c60655 | 986 | spin_unlock(&d->d_lock); |
e04527fe | 987 | tmp = dget_parent(d); |
a6c60655 MS |
988 | |
989 | dput(d); | |
990 | d = tmp; | |
991 | ||
992 | /* Absolute redirect: finished */ | |
993 | if (buf[buflen] == '/') | |
994 | break; | |
995 | buflen--; | |
996 | buf[buflen] = '/'; | |
997 | } | |
998 | ret = kstrdup(&buf[buflen], GFP_KERNEL); | |
999 | out_put: | |
1000 | dput(d); | |
1001 | kfree(buf); | |
1002 | out: | |
1003 | return ret ? ret : ERR_PTR(-ENOMEM); | |
1004 | } | |
1005 | ||
7bb08383 VG |
1006 | static bool ovl_need_absolute_redirect(struct dentry *dentry, bool samedir) |
1007 | { | |
1008 | struct dentry *lowerdentry; | |
1009 | ||
1010 | if (!samedir) | |
1011 | return true; | |
1012 | ||
1013 | if (d_is_dir(dentry)) | |
1014 | return false; | |
1015 | ||
1016 | /* | |
1017 | * For non-dir hardlinked files, we need absolute redirects | |
1018 | * in general as two upper hardlinks could be in different | |
1019 | * dirs. We could put a relative redirect now and convert | |
1020 | * it to absolute redirect later. But when nlink > 1 and | |
1021 | * indexing is on, that means relative redirect needs to be | |
1022 | * converted to absolute during copy up of another lower | |
1023 | * hardllink as well. | |
1024 | * | |
1025 | * So without optimizing too much, just check if lower is | |
1026 | * a hard link or not. If lower is hard link, put absolute | |
1027 | * redirect. | |
1028 | */ | |
1029 | lowerdentry = ovl_dentry_lower(dentry); | |
1030 | return (d_inode(lowerdentry)->i_nlink > 1); | |
1031 | } | |
1032 | ||
a6c60655 MS |
1033 | static int ovl_set_redirect(struct dentry *dentry, bool samedir) |
1034 | { | |
1035 | int err; | |
a0c236b1 | 1036 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
a6c60655 | 1037 | const char *redirect = ovl_dentry_get_redirect(dentry); |
7bb08383 | 1038 | bool absolute_redirect = ovl_need_absolute_redirect(dentry, samedir); |
a6c60655 | 1039 | |
7bb08383 | 1040 | if (redirect && (!absolute_redirect || redirect[0] == '/')) |
a6c60655 MS |
1041 | return 0; |
1042 | ||
7bb08383 | 1043 | redirect = ovl_get_redirect(dentry, absolute_redirect); |
a6c60655 MS |
1044 | if (IS_ERR(redirect)) |
1045 | return PTR_ERR(redirect); | |
1046 | ||
a0c236b1 | 1047 | err = ovl_check_setxattr(ofs, ovl_dentry_upper(dentry), |
21a22878 AG |
1048 | OVL_XATTR_REDIRECT, |
1049 | redirect, strlen(redirect), -EXDEV); | |
a6c60655 MS |
1050 | if (!err) { |
1051 | spin_lock(&dentry->d_lock); | |
1052 | ovl_dentry_set_redirect(dentry, redirect); | |
1053 | spin_unlock(&dentry->d_lock); | |
1054 | } else { | |
1055 | kfree(redirect); | |
1bd0a3ae | 1056 | pr_warn_ratelimited("failed to set redirect (%i)\n", |
da2e6b7e | 1057 | err); |
a6c60655 MS |
1058 | /* Fall back to userspace copy-up */ |
1059 | err = -EXDEV; | |
1060 | } | |
1061 | return err; | |
1062 | } | |
1063 | ||
549c7297 CB |
1064 | static int ovl_rename(struct user_namespace *mnt_userns, struct inode *olddir, |
1065 | struct dentry *old, struct inode *newdir, | |
1066 | struct dentry *new, unsigned int flags) | |
e9be9d5e MS |
1067 | { |
1068 | int err; | |
e9be9d5e MS |
1069 | struct dentry *old_upperdir; |
1070 | struct dentry *new_upperdir; | |
1071 | struct dentry *olddentry; | |
1072 | struct dentry *newdentry; | |
1073 | struct dentry *trap; | |
1074 | bool old_opaque; | |
1075 | bool new_opaque; | |
e9be9d5e | 1076 | bool cleanup_whiteout = false; |
0e32992f | 1077 | bool update_nlink = false; |
e9be9d5e | 1078 | bool overwrite = !(flags & RENAME_EXCHANGE); |
e36cb0b8 | 1079 | bool is_dir = d_is_dir(old); |
370e55ac | 1080 | bool new_is_dir = d_is_dir(new); |
a6c60655 | 1081 | bool samedir = olddir == newdir; |
e9be9d5e MS |
1082 | struct dentry *opaquedir = NULL; |
1083 | const struct cred *old_cred = NULL; | |
576bb263 | 1084 | struct ovl_fs *ofs = OVL_FS(old->d_sb); |
6d0a8a90 | 1085 | LIST_HEAD(list); |
e9be9d5e MS |
1086 | |
1087 | err = -EINVAL; | |
1088 | if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) | |
1089 | goto out; | |
1090 | ||
1091 | flags &= ~RENAME_NOREPLACE; | |
1092 | ||
e9be9d5e | 1093 | /* Don't copy up directory trees */ |
e9be9d5e | 1094 | err = -EXDEV; |
a6c60655 | 1095 | if (!ovl_can_move(old)) |
370e55ac | 1096 | goto out; |
a6c60655 | 1097 | if (!overwrite && !ovl_can_move(new)) |
e9be9d5e | 1098 | goto out; |
e9be9d5e | 1099 | |
6d0a8a90 AG |
1100 | if (overwrite && new_is_dir && !ovl_pure_upper(new)) { |
1101 | err = ovl_check_empty_dir(new, &list); | |
1102 | if (err) | |
1103 | goto out; | |
1104 | } | |
1105 | ||
1106 | if (overwrite) { | |
1107 | if (ovl_lower_positive(old)) { | |
1108 | if (!ovl_dentry_is_whiteout(new)) { | |
1109 | /* Whiteout source */ | |
1110 | flags |= RENAME_WHITEOUT; | |
1111 | } else { | |
1112 | /* Switch whiteouts */ | |
1113 | flags |= RENAME_EXCHANGE; | |
1114 | } | |
1115 | } else if (is_dir && ovl_dentry_is_whiteout(new)) { | |
1116 | flags |= RENAME_EXCHANGE; | |
1117 | cleanup_whiteout = true; | |
1118 | } | |
1119 | } | |
1120 | ||
e9be9d5e MS |
1121 | err = ovl_want_write(old); |
1122 | if (err) | |
1123 | goto out; | |
1124 | ||
1125 | err = ovl_copy_up(old); | |
1126 | if (err) | |
1127 | goto out_drop_write; | |
1128 | ||
1129 | err = ovl_copy_up(new->d_parent); | |
1130 | if (err) | |
1131 | goto out_drop_write; | |
1132 | if (!overwrite) { | |
1133 | err = ovl_copy_up(new); | |
1134 | if (err) | |
1135 | goto out_drop_write; | |
0e32992f AG |
1136 | } else if (d_inode(new)) { |
1137 | err = ovl_nlink_start(new); | |
5f8415d6 AG |
1138 | if (err) |
1139 | goto out_drop_write; | |
0e32992f AG |
1140 | |
1141 | update_nlink = true; | |
e9be9d5e MS |
1142 | } |
1143 | ||
1175b6b8 | 1144 | old_cred = ovl_override_creds(old->d_sb); |
e9be9d5e | 1145 | |
6d0a8a90 AG |
1146 | if (!list_empty(&list)) { |
1147 | opaquedir = ovl_clear_empty(new, &list); | |
e9be9d5e MS |
1148 | err = PTR_ERR(opaquedir); |
1149 | if (IS_ERR(opaquedir)) { | |
1150 | opaquedir = NULL; | |
1151 | goto out_revert_creds; | |
1152 | } | |
1153 | } | |
1154 | ||
e9be9d5e MS |
1155 | old_upperdir = ovl_dentry_upper(old->d_parent); |
1156 | new_upperdir = ovl_dentry_upper(new->d_parent); | |
1157 | ||
ee1d6d37 AG |
1158 | if (!samedir) { |
1159 | /* | |
1160 | * When moving a merge dir or non-dir with copy up origin into | |
f3a15685 AG |
1161 | * a new parent, we are marking the new parent dir "impure". |
1162 | * When ovl_iterate() iterates an "impure" upper dir, it will | |
1163 | * lookup the origin inodes of the entries to fill d_ino. | |
ee1d6d37 | 1164 | */ |
f3a15685 | 1165 | if (ovl_type_origin(old)) { |
ee1d6d37 AG |
1166 | err = ovl_set_impure(new->d_parent, new_upperdir); |
1167 | if (err) | |
1168 | goto out_revert_creds; | |
1169 | } | |
f3a15685 | 1170 | if (!overwrite && ovl_type_origin(new)) { |
ee1d6d37 AG |
1171 | err = ovl_set_impure(old->d_parent, old_upperdir); |
1172 | if (err) | |
1173 | goto out_revert_creds; | |
1174 | } | |
1175 | } | |
1176 | ||
e9be9d5e MS |
1177 | trap = lock_rename(new_upperdir, old_upperdir); |
1178 | ||
22f289ce CB |
1179 | olddentry = ovl_lookup_upper(ofs, old->d_name.name, old_upperdir, |
1180 | old->d_name.len); | |
11f37104 MS |
1181 | err = PTR_ERR(olddentry); |
1182 | if (IS_ERR(olddentry)) | |
1183 | goto out_unlock; | |
1184 | ||
1185 | err = -ESTALE; | |
9020df37 | 1186 | if (!ovl_matches_upper(old, olddentry)) |
11f37104 MS |
1187 | goto out_dput_old; |
1188 | ||
22f289ce CB |
1189 | newdentry = ovl_lookup_upper(ofs, new->d_name.name, new_upperdir, |
1190 | new->d_name.len); | |
11f37104 MS |
1191 | err = PTR_ERR(newdentry); |
1192 | if (IS_ERR(newdentry)) | |
1193 | goto out_dput_old; | |
1194 | ||
3ee23ff1 MS |
1195 | old_opaque = ovl_dentry_is_opaque(old); |
1196 | new_opaque = ovl_dentry_is_opaque(new); | |
1197 | ||
11f37104 | 1198 | err = -ESTALE; |
09d8b586 | 1199 | if (d_inode(new) && ovl_dentry_upper(new)) { |
e9be9d5e | 1200 | if (opaquedir) { |
11f37104 MS |
1201 | if (newdentry != opaquedir) |
1202 | goto out_dput; | |
e9be9d5e | 1203 | } else { |
9020df37 | 1204 | if (!ovl_matches_upper(new, newdentry)) |
11f37104 | 1205 | goto out_dput; |
e9be9d5e MS |
1206 | } |
1207 | } else { | |
a295aef6 ZL |
1208 | if (!d_is_negative(newdentry)) { |
1209 | if (!new_opaque || !ovl_is_whiteout(newdentry)) | |
1210 | goto out_dput; | |
1211 | } else { | |
1212 | if (flags & RENAME_EXCHANGE) | |
1213 | goto out_dput; | |
1214 | } | |
e9be9d5e MS |
1215 | } |
1216 | ||
e9be9d5e MS |
1217 | if (olddentry == trap) |
1218 | goto out_dput; | |
1219 | if (newdentry == trap) | |
1220 | goto out_dput; | |
1221 | ||
6889ee5a | 1222 | if (olddentry->d_inode == newdentry->d_inode) |
804032fa MS |
1223 | goto out_dput; |
1224 | ||
5cf5b477 | 1225 | err = 0; |
7bb08383 VG |
1226 | if (ovl_type_merge_or_lower(old)) |
1227 | err = ovl_set_redirect(old, samedir); | |
1228 | else if (is_dir && !old_opaque && ovl_type_merge(new->d_parent)) | |
1229 | err = ovl_set_opaque_xerr(old, olddentry, -EXDEV); | |
1230 | if (err) | |
1231 | goto out_dput; | |
1232 | ||
1233 | if (!overwrite && ovl_type_merge_or_lower(new)) | |
1234 | err = ovl_set_redirect(new, samedir); | |
1235 | else if (!overwrite && new_is_dir && !new_opaque && | |
1236 | ovl_type_merge(old->d_parent)) | |
1237 | err = ovl_set_opaque_xerr(new, newdentry, -EXDEV); | |
1238 | if (err) | |
1239 | goto out_dput; | |
e9be9d5e | 1240 | |
576bb263 | 1241 | err = ovl_do_rename(ofs, old_upperdir->d_inode, olddentry, |
3ee23ff1 MS |
1242 | new_upperdir->d_inode, newdentry, flags); |
1243 | if (err) | |
e9be9d5e | 1244 | goto out_dput; |
e9be9d5e MS |
1245 | |
1246 | if (cleanup_whiteout) | |
576bb263 | 1247 | ovl_cleanup(ofs, old_upperdir->d_inode, newdentry); |
e9be9d5e | 1248 | |
f681eb1d AG |
1249 | if (overwrite && d_inode(new)) { |
1250 | if (new_is_dir) | |
1251 | clear_nlink(d_inode(new)); | |
1252 | else | |
83552eac | 1253 | ovl_drop_nlink(new); |
f681eb1d AG |
1254 | } |
1255 | ||
d9854c87 MS |
1256 | ovl_dir_modified(old->d_parent, ovl_type_origin(old) || |
1257 | (!overwrite && ovl_type_origin(new))); | |
1258 | ovl_dir_modified(new->d_parent, ovl_type_origin(old) || | |
1259 | (d_inode(new) && ovl_type_origin(new))); | |
1260 | ||
1261 | /* copy ctime: */ | |
2878dffc | 1262 | ovl_copyattr(d_inode(old)); |
d9854c87 | 1263 | if (d_inode(new) && ovl_dentry_upper(new)) |
2878dffc | 1264 | ovl_copyattr(d_inode(new)); |
e9be9d5e MS |
1265 | |
1266 | out_dput: | |
1267 | dput(newdentry); | |
11f37104 MS |
1268 | out_dput_old: |
1269 | dput(olddentry); | |
e9be9d5e MS |
1270 | out_unlock: |
1271 | unlock_rename(new_upperdir, old_upperdir); | |
1272 | out_revert_creds: | |
1175b6b8 | 1273 | revert_creds(old_cred); |
0e32992f AG |
1274 | if (update_nlink) |
1275 | ovl_nlink_end(new); | |
e9be9d5e MS |
1276 | out_drop_write: |
1277 | ovl_drop_write(old); | |
1278 | out: | |
1279 | dput(opaquedir); | |
6d0a8a90 | 1280 | ovl_cache_free(&list); |
e9be9d5e MS |
1281 | return err; |
1282 | } | |
1283 | ||
1284 | const struct inode_operations ovl_dir_inode_operations = { | |
1285 | .lookup = ovl_lookup, | |
1286 | .mkdir = ovl_mkdir, | |
1287 | .symlink = ovl_symlink, | |
1288 | .unlink = ovl_unlink, | |
1289 | .rmdir = ovl_rmdir, | |
6c02cb59 | 1290 | .rename = ovl_rename, |
e9be9d5e MS |
1291 | .link = ovl_link, |
1292 | .setattr = ovl_setattr, | |
1293 | .create = ovl_create, | |
1294 | .mknod = ovl_mknod, | |
1295 | .permission = ovl_permission, | |
5b712091 | 1296 | .getattr = ovl_getattr, |
e9be9d5e | 1297 | .listxattr = ovl_listxattr, |
6c0a8bfb CB |
1298 | .get_inode_acl = ovl_get_inode_acl, |
1299 | .get_acl = ovl_get_acl, | |
0e641857 | 1300 | .set_acl = ovl_set_acl, |
d719e8f2 | 1301 | .update_time = ovl_update_time, |
66dbfabf MS |
1302 | .fileattr_get = ovl_fileattr_get, |
1303 | .fileattr_set = ovl_fileattr_set, | |
e9be9d5e | 1304 | }; |