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> |
9a87907d | 17 | #include <linux/backing-file.h> |
e9be9d5e MS |
18 | #include "overlayfs.h" |
19 | ||
3ea22a71 MS |
20 | static unsigned short ovl_redirect_max = 256; |
21 | module_param_named(redirect_max, ovl_redirect_max, ushort, 0644); | |
253e7483 | 22 | MODULE_PARM_DESC(redirect_max, |
3ea22a71 MS |
23 | "Maximum length of absolute redirect xattr value"); |
24 | ||
4120fe64 VG |
25 | static int ovl_set_redirect(struct dentry *dentry, bool samedir); |
26 | ||
576bb263 | 27 | int ovl_cleanup(struct ovl_fs *ofs, struct inode *wdir, struct dentry *wdentry) |
e9be9d5e MS |
28 | { |
29 | int err; | |
30 | ||
31 | dget(wdentry); | |
e36cb0b8 | 32 | if (d_is_dir(wdentry)) |
576bb263 | 33 | err = ovl_do_rmdir(ofs, wdir, wdentry); |
e9be9d5e | 34 | else |
576bb263 | 35 | err = ovl_do_unlink(ofs, wdir, wdentry); |
e9be9d5e MS |
36 | dput(wdentry); |
37 | ||
38 | if (err) { | |
1bd0a3ae | 39 | pr_err("cleanup of '%pd2' failed (%i)\n", |
e9be9d5e MS |
40 | wdentry, err); |
41 | } | |
415543d5 AG |
42 | |
43 | return err; | |
e9be9d5e MS |
44 | } |
45 | ||
576bb263 | 46 | struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir) |
e9be9d5e MS |
47 | { |
48 | struct dentry *temp; | |
49 | char name[20]; | |
6a45b362 | 50 | static atomic_t temp_id = ATOMIC_INIT(0); |
e9be9d5e | 51 | |
6a45b362 RW |
52 | /* counter is allowed to wrap, since temp dentries are ephemeral */ |
53 | snprintf(name, sizeof(name), "#%x", atomic_inc_return(&temp_id)); | |
e9be9d5e | 54 | |
22f289ce | 55 | temp = ovl_lookup_upper(ofs, name, workdir, strlen(name)); |
e9be9d5e | 56 | if (!IS_ERR(temp) && temp->d_inode) { |
1bd0a3ae | 57 | pr_err("workdir/%s already exists\n", name); |
e9be9d5e MS |
58 | dput(temp); |
59 | temp = ERR_PTR(-EIO); | |
60 | } | |
61 | ||
62 | return temp; | |
63 | } | |
64 | ||
65 | /* caller holds i_mutex on workdir */ | |
c21c839b | 66 | static struct dentry *ovl_whiteout(struct ovl_fs *ofs) |
e9be9d5e MS |
67 | { |
68 | int err; | |
69 | struct dentry *whiteout; | |
c21c839b | 70 | struct dentry *workdir = ofs->workdir; |
e9be9d5e MS |
71 | struct inode *wdir = workdir->d_inode; |
72 | ||
c21c839b | 73 | if (!ofs->whiteout) { |
576bb263 | 74 | whiteout = ovl_lookup_temp(ofs, workdir); |
c21c839b CX |
75 | if (IS_ERR(whiteout)) |
76 | goto out; | |
e9be9d5e | 77 | |
576bb263 | 78 | err = ovl_do_whiteout(ofs, wdir, whiteout); |
c21c839b CX |
79 | if (err) { |
80 | dput(whiteout); | |
81 | whiteout = ERR_PTR(err); | |
82 | goto out; | |
83 | } | |
84 | ofs->whiteout = whiteout; | |
e9be9d5e MS |
85 | } |
86 | ||
e4599d4b | 87 | if (!ofs->no_shared_whiteout) { |
576bb263 | 88 | whiteout = ovl_lookup_temp(ofs, workdir); |
c21c839b CX |
89 | if (IS_ERR(whiteout)) |
90 | goto out; | |
91 | ||
576bb263 | 92 | err = ovl_do_link(ofs, ofs->whiteout, wdir, whiteout); |
c21c839b CX |
93 | if (!err) |
94 | goto out; | |
95 | ||
96 | if (err != -EMLINK) { | |
97 | pr_warn("Failed to link whiteout - disabling whiteout inode sharing(nlink=%u, err=%i)\n", | |
98 | ofs->whiteout->d_inode->i_nlink, err); | |
e4599d4b | 99 | ofs->no_shared_whiteout = true; |
c21c839b CX |
100 | } |
101 | dput(whiteout); | |
102 | } | |
103 | whiteout = ofs->whiteout; | |
104 | ofs->whiteout = NULL; | |
105 | out: | |
e9be9d5e MS |
106 | return whiteout; |
107 | } | |
108 | ||
e7dd0e71 | 109 | /* Caller must hold i_mutex on both workdir and dir */ |
c21c839b | 110 | int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, |
e7dd0e71 AG |
111 | struct dentry *dentry) |
112 | { | |
c21c839b | 113 | struct inode *wdir = ofs->workdir->d_inode; |
e7dd0e71 AG |
114 | struct dentry *whiteout; |
115 | int err; | |
116 | int flags = 0; | |
117 | ||
c21c839b | 118 | whiteout = ovl_whiteout(ofs); |
e7dd0e71 AG |
119 | err = PTR_ERR(whiteout); |
120 | if (IS_ERR(whiteout)) | |
121 | return err; | |
122 | ||
123 | if (d_is_dir(dentry)) | |
124 | flags = RENAME_EXCHANGE; | |
125 | ||
576bb263 | 126 | err = ovl_do_rename(ofs, wdir, whiteout, dir, dentry, flags); |
e7dd0e71 AG |
127 | if (err) |
128 | goto kill_whiteout; | |
129 | if (flags) | |
576bb263 | 130 | ovl_cleanup(ofs, wdir, dentry); |
e7dd0e71 AG |
131 | |
132 | out: | |
133 | dput(whiteout); | |
134 | return err; | |
135 | ||
136 | kill_whiteout: | |
576bb263 | 137 | ovl_cleanup(ofs, wdir, whiteout); |
e7dd0e71 AG |
138 | goto out; |
139 | } | |
140 | ||
576bb263 CB |
141 | int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, |
142 | struct dentry **newdentry, umode_t mode) | |
f73cc77c AV |
143 | { |
144 | int err; | |
145 | struct dentry *d, *dentry = *newdentry; | |
146 | ||
576bb263 | 147 | err = ovl_do_mkdir(ofs, dir, dentry, mode); |
f73cc77c AV |
148 | if (err) |
149 | return err; | |
150 | ||
151 | if (likely(!d_unhashed(dentry))) | |
152 | return 0; | |
153 | ||
154 | /* | |
155 | * vfs_mkdir() may succeed and leave the dentry passed | |
156 | * to it unhashed and negative. If that happens, try to | |
157 | * lookup a new hashed and positive dentry. | |
158 | */ | |
22f289ce CB |
159 | d = ovl_lookup_upper(ofs, dentry->d_name.name, dentry->d_parent, |
160 | dentry->d_name.len); | |
f73cc77c | 161 | if (IS_ERR(d)) { |
1bd0a3ae | 162 | pr_warn("failed lookup after mkdir (%pd2, err=%i).\n", |
f73cc77c AV |
163 | dentry, err); |
164 | return PTR_ERR(d); | |
165 | } | |
166 | dput(dentry); | |
167 | *newdentry = d; | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
576bb263 CB |
172 | struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir, |
173 | struct dentry *newdentry, struct ovl_cattr *attr) | |
e9be9d5e MS |
174 | { |
175 | int err; | |
176 | ||
95a1c815 MS |
177 | if (IS_ERR(newdentry)) |
178 | return newdentry; | |
179 | ||
180 | err = -ESTALE; | |
e9be9d5e | 181 | if (newdentry->d_inode) |
95a1c815 | 182 | goto out; |
e9be9d5e | 183 | |
471ec5dc | 184 | if (attr->hardlink) { |
576bb263 | 185 | err = ovl_do_link(ofs, attr->hardlink, dir, newdentry); |
e9be9d5e | 186 | } else { |
32a3d848 | 187 | switch (attr->mode & S_IFMT) { |
e9be9d5e | 188 | case S_IFREG: |
576bb263 | 189 | err = ovl_do_create(ofs, dir, newdentry, attr->mode); |
e9be9d5e MS |
190 | break; |
191 | ||
192 | case S_IFDIR: | |
f73cc77c | 193 | /* mkdir is special... */ |
576bb263 | 194 | err = ovl_mkdir_real(ofs, dir, &newdentry, attr->mode); |
e9be9d5e MS |
195 | break; |
196 | ||
197 | case S_IFCHR: | |
198 | case S_IFBLK: | |
199 | case S_IFIFO: | |
200 | case S_IFSOCK: | |
576bb263 | 201 | err = ovl_do_mknod(ofs, dir, newdentry, attr->mode, |
6cf00764 | 202 | attr->rdev); |
e9be9d5e MS |
203 | break; |
204 | ||
205 | case S_IFLNK: | |
576bb263 | 206 | err = ovl_do_symlink(ofs, dir, newdentry, attr->link); |
e9be9d5e MS |
207 | break; |
208 | ||
209 | default: | |
210 | err = -EPERM; | |
211 | } | |
212 | } | |
213 | if (!err && WARN_ON(!newdentry->d_inode)) { | |
214 | /* | |
215 | * Not quite sure if non-instantiated dentry is legal or not. | |
216 | * VFS doesn't seem to care so check and warn here. | |
217 | */ | |
dd8ac699 | 218 | err = -EIO; |
e9be9d5e | 219 | } |
95a1c815 MS |
220 | out: |
221 | if (err) { | |
222 | dput(newdentry); | |
223 | return ERR_PTR(err); | |
224 | } | |
225 | return newdentry; | |
e9be9d5e MS |
226 | } |
227 | ||
576bb263 CB |
228 | struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, |
229 | struct ovl_cattr *attr) | |
137ec526 | 230 | { |
576bb263 CB |
231 | return ovl_create_real(ofs, d_inode(workdir), |
232 | ovl_lookup_temp(ofs, workdir), attr); | |
137ec526 AG |
233 | } |
234 | ||
21a22878 AG |
235 | static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper, |
236 | int xerr) | |
e9be9d5e | 237 | { |
a0c236b1 | 238 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
5cf5b477 MS |
239 | int err; |
240 | ||
a0c236b1 | 241 | err = ovl_check_setxattr(ofs, upper, OVL_XATTR_OPAQUE, "y", 1, xerr); |
5cf5b477 MS |
242 | if (!err) |
243 | ovl_dentry_set_opaque(dentry); | |
244 | ||
245 | return err; | |
e9be9d5e MS |
246 | } |
247 | ||
21a22878 AG |
248 | static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) |
249 | { | |
250 | /* | |
251 | * Fail with -EIO when trying to create opaque dir and upper doesn't | |
252 | * support xattrs. ovl_rename() calls ovl_set_opaque_xerr(-EXDEV) to | |
253 | * return a specific error for noxattr case. | |
254 | */ | |
255 | return ovl_set_opaque_xerr(dentry, upperdentry, -EIO); | |
256 | } | |
257 | ||
01b39dcc AG |
258 | /* |
259 | * Common operations required to be done after creation of file on upper. | |
260 | * If @hardlink is false, then @inode is a pre-allocated inode, we may or | |
261 | * may not use to instantiate the new dentry. | |
262 | */ | |
263 | static int ovl_instantiate(struct dentry *dentry, struct inode *inode, | |
9a87907d | 264 | struct dentry *newdentry, bool hardlink, struct file *tmpfile) |
72e48481 | 265 | { |
01b39dcc AG |
266 | struct ovl_inode_params oip = { |
267 | .upperdentry = newdentry, | |
268 | .newinode = inode, | |
269 | }; | |
270 | ||
55acc661 | 271 | ovl_dentry_set_upper_alias(dentry); |
0af950f5 | 272 | ovl_dentry_init_reval(dentry, newdentry, NULL); |
f4288844 | 273 | |
51f7e52d | 274 | if (!hardlink) { |
01b39dcc AG |
275 | /* |
276 | * ovl_obtain_alias() can be called after ovl_create_real() | |
277 | * and before we get here, so we may get an inode from cache | |
278 | * with the same real upperdentry that is not the inode we | |
279 | * pre-allocated. In this case we will use the cached inode | |
280 | * to instantiate the new dentry. | |
281 | * | |
282 | * XXX: if we ever use ovl_obtain_alias() to decode directory | |
283 | * file handles, need to use ovl_get_inode_locked() and | |
284 | * d_instantiate_new() here to prevent from creating two | |
285 | * hashed directory inode aliases. | |
286 | */ | |
287 | inode = ovl_get_inode(dentry->d_sb, &oip); | |
acf3062a | 288 | if (IS_ERR(inode)) |
01b39dcc | 289 | return PTR_ERR(inode); |
28166ab3 VG |
290 | if (inode == oip.newinode) |
291 | ovl_set_flag(OVL_UPPERDATA, inode); | |
51f7e52d | 292 | } else { |
09d8b586 MS |
293 | WARN_ON(ovl_inode_real(inode) != d_inode(newdentry)); |
294 | dput(newdentry); | |
51f7e52d MS |
295 | inc_nlink(inode); |
296 | } | |
01b39dcc | 297 | |
9a87907d MS |
298 | if (tmpfile) |
299 | d_mark_tmpfile(tmpfile, inode); | |
300 | ||
72e48481 | 301 | d_instantiate(dentry, inode); |
01b39dcc | 302 | if (inode != oip.newinode) { |
1bd0a3ae | 303 | pr_warn_ratelimited("newly created inode found in cache (%pd2)\n", |
01b39dcc AG |
304 | dentry); |
305 | } | |
306 | ||
5b6c9053 AG |
307 | /* Force lookup of new upper hardlink to find its lower */ |
308 | if (hardlink) | |
309 | d_drop(dentry); | |
01b39dcc AG |
310 | |
311 | return 0; | |
72e48481 VG |
312 | } |
313 | ||
97c684cc AG |
314 | static bool ovl_type_merge(struct dentry *dentry) |
315 | { | |
316 | return OVL_TYPE_MERGE(ovl_path_type(dentry)); | |
317 | } | |
318 | ||
ee1d6d37 AG |
319 | static bool ovl_type_origin(struct dentry *dentry) |
320 | { | |
321 | return OVL_TYPE_ORIGIN(ovl_path_type(dentry)); | |
322 | } | |
323 | ||
e9be9d5e | 324 | static int ovl_create_upper(struct dentry *dentry, struct inode *inode, |
471ec5dc | 325 | struct ovl_cattr *attr) |
e9be9d5e | 326 | { |
1fc31aac | 327 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e MS |
328 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); |
329 | struct inode *udir = upperdir->d_inode; | |
330 | struct dentry *newdentry; | |
331 | int err; | |
332 | ||
5955102c | 333 | inode_lock_nested(udir, I_MUTEX_PARENT); |
576bb263 | 334 | newdentry = ovl_create_real(ofs, udir, |
22f289ce CB |
335 | ovl_lookup_upper(ofs, dentry->d_name.name, |
336 | upperdir, dentry->d_name.len), | |
95a1c815 | 337 | attr); |
e9be9d5e MS |
338 | err = PTR_ERR(newdentry); |
339 | if (IS_ERR(newdentry)) | |
340 | goto out_unlock; | |
e9be9d5e | 341 | |
1fc31aac VY |
342 | if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry) && |
343 | !ovl_allow_offline_changes(ofs)) { | |
97c684cc AG |
344 | /* Setting opaque here is just an optimization, allow to fail */ |
345 | ovl_set_opaque(dentry, newdentry); | |
346 | } | |
347 | ||
9a87907d MS |
348 | ovl_dir_modified(dentry->d_parent, false); |
349 | err = ovl_instantiate(dentry, inode, newdentry, !!attr->hardlink, NULL); | |
01b39dcc AG |
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 | 480 | err = -ESTALE; |
bc8df7a3 | 481 | if (d_is_negative(upper) || !ovl_upper_is_whiteout(ofs, upper)) |
5e127580 MS |
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 | } | |
9a87907d MS |
533 | ovl_dir_modified(dentry->d_parent, false); |
534 | err = ovl_instantiate(dentry, inode, newdentry, hardlink, NULL); | |
52d5a0c6 | 535 | if (err) { |
576bb263 | 536 | ovl_cleanup(ofs, udir, newdentry); |
52d5a0c6 | 537 | dput(newdentry); |
538 | } | |
e9be9d5e | 539 | out_dput: |
95a1c815 | 540 | dput(upper); |
e9be9d5e MS |
541 | out_unlock: |
542 | unlock_rename(workdir, upperdir); | |
543 | out: | |
38b25697 MS |
544 | if (!hardlink) { |
545 | posix_acl_release(acl); | |
546 | posix_acl_release(default_acl); | |
547 | } | |
e9be9d5e MS |
548 | return err; |
549 | ||
550 | out_cleanup: | |
576bb263 | 551 | ovl_cleanup(ofs, wdir, newdentry); |
95a1c815 MS |
552 | dput(newdentry); |
553 | goto out_dput; | |
e9be9d5e MS |
554 | } |
555 | ||
9a87907d MS |
556 | static int ovl_setup_cred_for_create(struct dentry *dentry, struct inode *inode, |
557 | umode_t mode, const struct cred *old_cred) | |
558 | { | |
559 | int err; | |
560 | struct cred *override_cred; | |
561 | ||
562 | override_cred = prepare_creds(); | |
563 | if (!override_cred) | |
564 | return -ENOMEM; | |
565 | ||
566 | override_cred->fsuid = inode->i_uid; | |
567 | override_cred->fsgid = inode->i_gid; | |
568 | err = security_dentry_create_files_as(dentry, mode, &dentry->d_name, | |
569 | old_cred, override_cred); | |
570 | if (err) { | |
571 | put_cred(override_cred); | |
572 | return err; | |
573 | } | |
574 | put_cred(override_creds(override_cred)); | |
575 | put_cred(override_cred); | |
576 | ||
577 | return 0; | |
578 | } | |
579 | ||
51f7e52d | 580 | static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, |
471ec5dc | 581 | struct ovl_cattr *attr, bool origin) |
e9be9d5e MS |
582 | { |
583 | int err; | |
1175b6b8 | 584 | const struct cred *old_cred; |
ea3dad18 | 585 | struct dentry *parent = dentry->d_parent; |
e9be9d5e | 586 | |
1175b6b8 | 587 | old_cred = ovl_override_creds(dentry->d_sb); |
ea3dad18 AG |
588 | |
589 | /* | |
590 | * When linking a file with copy up origin into a new parent, mark the | |
591 | * new parent dir "impure". | |
592 | */ | |
593 | if (origin) { | |
594 | err = ovl_set_impure(parent, ovl_dentry_upper(parent)); | |
595 | if (err) | |
596 | goto out_revert_creds; | |
597 | } | |
598 | ||
5b0db512 | 599 | if (!attr->hardlink) { |
5b0db512 ZT |
600 | /* |
601 | * In the creation cases(create, mkdir, mknod, symlink), | |
602 | * ovl should transfer current's fs{u,g}id to underlying | |
603 | * fs. Because underlying fs want to initialize its new | |
604 | * inode owner using current's fs{u,g}id. And in this | |
605 | * case, the @inode is a new inode that is initialized | |
606 | * in inode_init_owner() to current's fs{u,g}id. So use | |
607 | * the inode's i_{u,g}id to override the cred's fs{u,g}id. | |
608 | * | |
609 | * But in the other hardlink case, ovl_link() does not | |
610 | * create a new inode, so just use the ovl mounter's | |
611 | * fs{u,g}id. | |
612 | */ | |
9a87907d MS |
613 | err = ovl_setup_cred_for_create(dentry, inode, attr->mode, old_cred); |
614 | if (err) | |
5b0db512 | 615 | goto out_revert_creds; |
e9be9d5e | 616 | } |
5b0db512 ZT |
617 | |
618 | if (!ovl_dentry_is_whiteout(dentry)) | |
619 | err = ovl_create_upper(dentry, inode, attr); | |
620 | else | |
621 | err = ovl_create_over_whiteout(dentry, inode, attr); | |
622 | ||
2602625b | 623 | out_revert_creds: |
1175b6b8 | 624 | revert_creds(old_cred); |
e9be9d5e MS |
625 | return err; |
626 | } | |
627 | ||
628 | static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, | |
629 | const char *link) | |
630 | { | |
631 | int err; | |
51f7e52d | 632 | struct inode *inode; |
471ec5dc | 633 | struct ovl_cattr attr = { |
51f7e52d | 634 | .rdev = rdev, |
32a3d848 | 635 | .link = link, |
51f7e52d | 636 | }; |
e9be9d5e | 637 | |
162d0644 AG |
638 | err = ovl_copy_up(dentry->d_parent); |
639 | if (err) | |
640 | return err; | |
641 | ||
e9be9d5e | 642 | err = ovl_want_write(dentry); |
51f7e52d MS |
643 | if (err) |
644 | goto out; | |
645 | ||
01b39dcc | 646 | /* Preallocate inode to be used by ovl_get_inode() */ |
51f7e52d | 647 | err = -ENOMEM; |
ca4c8a3a | 648 | inode = ovl_new_inode(dentry->d_sb, mode, rdev); |
51f7e52d MS |
649 | if (!inode) |
650 | goto out_drop_write; | |
651 | ||
6faf05c2 MS |
652 | spin_lock(&inode->i_lock); |
653 | inode->i_state |= I_CREATING; | |
654 | spin_unlock(&inode->i_lock); | |
655 | ||
f2d40141 | 656 | inode_init_owner(&nop_mnt_idmap, inode, dentry->d_parent->d_inode, mode); |
32a3d848 | 657 | attr.mode = inode->i_mode; |
51f7e52d | 658 | |
471ec5dc | 659 | err = ovl_create_or_link(dentry, inode, &attr, false); |
01b39dcc AG |
660 | /* Did we end up using the preallocated inode? */ |
661 | if (inode != d_inode(dentry)) | |
51f7e52d | 662 | iput(inode); |
e9be9d5e | 663 | |
51f7e52d MS |
664 | out_drop_write: |
665 | ovl_drop_write(dentry); | |
666 | out: | |
e9be9d5e MS |
667 | return err; |
668 | } | |
669 | ||
6c960e68 | 670 | static int ovl_create(struct mnt_idmap *idmap, struct inode *dir, |
549c7297 | 671 | struct dentry *dentry, umode_t mode, bool excl) |
e9be9d5e MS |
672 | { |
673 | return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL); | |
674 | } | |
675 | ||
c54bd91e | 676 | static int ovl_mkdir(struct mnt_idmap *idmap, struct inode *dir, |
549c7297 | 677 | struct dentry *dentry, umode_t mode) |
e9be9d5e MS |
678 | { |
679 | return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL); | |
680 | } | |
681 | ||
5ebb29be | 682 | static int ovl_mknod(struct mnt_idmap *idmap, struct inode *dir, |
549c7297 | 683 | struct dentry *dentry, umode_t mode, dev_t rdev) |
e9be9d5e MS |
684 | { |
685 | /* Don't allow creation of "whiteout" on overlay */ | |
686 | if (S_ISCHR(mode) && rdev == WHITEOUT_DEV) | |
687 | return -EPERM; | |
688 | ||
689 | return ovl_create_object(dentry, mode, rdev, NULL); | |
690 | } | |
691 | ||
7a77db95 | 692 | static int ovl_symlink(struct mnt_idmap *idmap, struct inode *dir, |
549c7297 | 693 | struct dentry *dentry, const char *link) |
e9be9d5e MS |
694 | { |
695 | return ovl_create_object(dentry, S_IFLNK, 0, link); | |
696 | } | |
697 | ||
91ff20f3 AG |
698 | static int ovl_set_link_redirect(struct dentry *dentry) |
699 | { | |
700 | const struct cred *old_cred; | |
701 | int err; | |
702 | ||
703 | old_cred = ovl_override_creds(dentry->d_sb); | |
704 | err = ovl_set_redirect(dentry, false); | |
705 | revert_creds(old_cred); | |
706 | ||
707 | return err; | |
708 | } | |
709 | ||
e9be9d5e MS |
710 | static int ovl_link(struct dentry *old, struct inode *newdir, |
711 | struct dentry *new) | |
712 | { | |
713 | int err; | |
51f7e52d | 714 | struct inode *inode; |
e9be9d5e | 715 | |
162d0644 | 716 | err = ovl_copy_up(old); |
e9be9d5e MS |
717 | if (err) |
718 | goto out; | |
719 | ||
162d0644 | 720 | err = ovl_copy_up(new->d_parent); |
e9be9d5e | 721 | if (err) |
162d0644 | 722 | goto out; |
e9be9d5e | 723 | |
162d0644 | 724 | err = ovl_nlink_start(old); |
6cd07870 | 725 | if (err) |
162d0644 | 726 | goto out; |
6cd07870 | 727 | |
4120fe64 | 728 | if (ovl_is_metacopy_dentry(old)) { |
91ff20f3 | 729 | err = ovl_set_link_redirect(old); |
4120fe64 | 730 | if (err) |
162d0644 | 731 | goto out_nlink_end; |
4120fe64 VG |
732 | } |
733 | ||
51f7e52d MS |
734 | inode = d_inode(old); |
735 | ihold(inode); | |
736 | ||
471ec5dc AG |
737 | err = ovl_create_or_link(new, inode, |
738 | &(struct ovl_cattr) {.hardlink = ovl_dentry_upper(old)}, | |
739 | ovl_type_origin(old)); | |
51f7e52d MS |
740 | if (err) |
741 | iput(inode); | |
e9be9d5e | 742 | |
162d0644 | 743 | out_nlink_end: |
0e32992f | 744 | ovl_nlink_end(old); |
e9be9d5e MS |
745 | out: |
746 | return err; | |
747 | } | |
748 | ||
9020df37 MS |
749 | static bool ovl_matches_upper(struct dentry *dentry, struct dentry *upper) |
750 | { | |
751 | return d_inode(ovl_dentry_upper(dentry)) == d_inode(upper); | |
752 | } | |
753 | ||
6d0a8a90 AG |
754 | static int ovl_remove_and_whiteout(struct dentry *dentry, |
755 | struct list_head *list) | |
e9be9d5e | 756 | { |
c21c839b | 757 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e | 758 | struct dentry *workdir = ovl_workdir(dentry); |
e9be9d5e | 759 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); |
e9be9d5e MS |
760 | struct dentry *upper; |
761 | struct dentry *opaquedir = NULL; | |
762 | int err; | |
763 | ||
cc6f67bc MS |
764 | if (WARN_ON(!workdir)) |
765 | return -EROFS; | |
766 | ||
6d0a8a90 AG |
767 | if (!list_empty(list)) { |
768 | opaquedir = ovl_clear_empty(dentry, list); | |
30c17ebf MS |
769 | err = PTR_ERR(opaquedir); |
770 | if (IS_ERR(opaquedir)) | |
771 | goto out; | |
e9be9d5e MS |
772 | } |
773 | ||
774 | err = ovl_lock_rename_workdir(workdir, upperdir); | |
775 | if (err) | |
776 | goto out_dput; | |
777 | ||
22f289ce CB |
778 | upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir, |
779 | dentry->d_name.len); | |
cfc9fde0 MP |
780 | err = PTR_ERR(upper); |
781 | if (IS_ERR(upper)) | |
e9be9d5e MS |
782 | goto out_unlock; |
783 | ||
cfc9fde0 MP |
784 | err = -ESTALE; |
785 | if ((opaquedir && upper != opaquedir) || | |
786 | (!opaquedir && ovl_dentry_upper(dentry) && | |
9020df37 | 787 | !ovl_matches_upper(dentry, upper))) { |
cfc9fde0 MP |
788 | goto out_dput_upper; |
789 | } | |
e9be9d5e | 790 | |
c21c839b | 791 | err = ovl_cleanup_and_whiteout(ofs, d_inode(upperdir), upper); |
cfc9fde0 | 792 | if (err) |
e7dd0e71 | 793 | goto out_d_drop; |
e9be9d5e | 794 | |
d9854c87 | 795 | ovl_dir_modified(dentry->d_parent, true); |
e9be9d5e MS |
796 | out_d_drop: |
797 | d_drop(dentry); | |
cfc9fde0 MP |
798 | out_dput_upper: |
799 | dput(upper); | |
e9be9d5e MS |
800 | out_unlock: |
801 | unlock_rename(workdir, upperdir); | |
802 | out_dput: | |
803 | dput(opaquedir); | |
804 | out: | |
805 | return err; | |
e9be9d5e MS |
806 | } |
807 | ||
6d0a8a90 AG |
808 | static int ovl_remove_upper(struct dentry *dentry, bool is_dir, |
809 | struct list_head *list) | |
e9be9d5e | 810 | { |
576bb263 | 811 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
e9be9d5e MS |
812 | struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); |
813 | struct inode *dir = upperdir->d_inode; | |
11f37104 | 814 | struct dentry *upper; |
d1595119 | 815 | struct dentry *opaquedir = NULL; |
e9be9d5e MS |
816 | int err; |
817 | ||
6d0a8a90 AG |
818 | if (!list_empty(list)) { |
819 | opaquedir = ovl_clear_empty(dentry, list); | |
d1595119 AG |
820 | err = PTR_ERR(opaquedir); |
821 | if (IS_ERR(opaquedir)) | |
822 | goto out; | |
823 | } | |
824 | ||
5955102c | 825 | inode_lock_nested(dir, I_MUTEX_PARENT); |
22f289ce CB |
826 | upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir, |
827 | dentry->d_name.len); | |
11f37104 MS |
828 | err = PTR_ERR(upper); |
829 | if (IS_ERR(upper)) | |
830 | goto out_unlock; | |
831 | ||
e9be9d5e | 832 | err = -ESTALE; |
d1595119 | 833 | if ((opaquedir && upper != opaquedir) || |
9020df37 | 834 | (!opaquedir && !ovl_matches_upper(dentry, upper))) |
d1595119 AG |
835 | goto out_dput_upper; |
836 | ||
837 | if (is_dir) | |
576bb263 | 838 | err = ovl_do_rmdir(ofs, dir, upper); |
d1595119 | 839 | else |
576bb263 | 840 | err = ovl_do_unlink(ofs, dir, upper); |
d9854c87 | 841 | ovl_dir_modified(dentry->d_parent, ovl_type_origin(dentry)); |
e9be9d5e MS |
842 | |
843 | /* | |
844 | * Keeping this dentry hashed would mean having to release | |
845 | * upperpath/lowerpath, which could only be done if we are the | |
846 | * sole user of this dentry. Too tricky... Just unhash for | |
847 | * now. | |
848 | */ | |
ce9113bb RW |
849 | if (!err) |
850 | d_drop(dentry); | |
d1595119 AG |
851 | out_dput_upper: |
852 | dput(upper); | |
11f37104 | 853 | out_unlock: |
5955102c | 854 | inode_unlock(dir); |
d1595119 AG |
855 | dput(opaquedir); |
856 | out: | |
e9be9d5e MS |
857 | return err; |
858 | } | |
859 | ||
6d0a8a90 AG |
860 | static bool ovl_pure_upper(struct dentry *dentry) |
861 | { | |
862 | return !ovl_dentry_lower(dentry) && | |
863 | !ovl_test_flag(OVL_WHITEOUTS, d_inode(dentry)); | |
864 | } | |
865 | ||
83552eac MS |
866 | static void ovl_drop_nlink(struct dentry *dentry) |
867 | { | |
868 | struct inode *inode = d_inode(dentry); | |
869 | struct dentry *alias; | |
870 | ||
871 | /* Try to find another, hashed alias */ | |
872 | spin_lock(&inode->i_lock); | |
873 | hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { | |
874 | if (alias != dentry && !d_unhashed(alias)) | |
875 | break; | |
876 | } | |
877 | spin_unlock(&inode->i_lock); | |
878 | ||
879 | /* | |
880 | * Changes to underlying layers may cause i_nlink to lose sync with | |
881 | * reality. In this case prevent the link count from going to zero | |
882 | * prematurely. | |
883 | */ | |
884 | if (inode->i_nlink > !!alias) | |
885 | drop_nlink(inode); | |
886 | } | |
887 | ||
e9be9d5e MS |
888 | static int ovl_do_remove(struct dentry *dentry, bool is_dir) |
889 | { | |
e9be9d5e | 890 | int err; |
1175b6b8 | 891 | const struct cred *old_cred; |
6d0a8a90 AG |
892 | bool lower_positive = ovl_lower_positive(dentry); |
893 | LIST_HEAD(list); | |
894 | ||
895 | /* No need to clean pure upper removed by vfs_rmdir() */ | |
896 | if (is_dir && (lower_positive || !ovl_pure_upper(dentry))) { | |
897 | err = ovl_check_empty_dir(dentry, &list); | |
898 | if (err) | |
899 | goto out; | |
900 | } | |
1175b6b8 | 901 | |
e9be9d5e MS |
902 | err = ovl_copy_up(dentry->d_parent); |
903 | if (err) | |
162d0644 | 904 | goto out; |
e9be9d5e | 905 | |
0e32992f | 906 | err = ovl_nlink_start(dentry); |
5f8415d6 | 907 | if (err) |
162d0644 | 908 | goto out; |
e9be9d5e | 909 | |
1175b6b8 | 910 | old_cred = ovl_override_creds(dentry->d_sb); |
6d0a8a90 AG |
911 | if (!lower_positive) |
912 | err = ovl_remove_upper(dentry, is_dir, &list); | |
1175b6b8 | 913 | else |
6d0a8a90 | 914 | err = ovl_remove_and_whiteout(dentry, &list); |
1175b6b8 | 915 | revert_creds(old_cred); |
dbc816d0 MS |
916 | if (!err) { |
917 | if (is_dir) | |
918 | clear_nlink(dentry->d_inode); | |
919 | else | |
83552eac | 920 | ovl_drop_nlink(dentry); |
dbc816d0 | 921 | } |
0e32992f | 922 | ovl_nlink_end(dentry); |
d9854c87 MS |
923 | |
924 | /* | |
925 | * Copy ctime | |
926 | * | |
927 | * Note: we fail to update ctime if there was no copy-up, only a | |
928 | * whiteout | |
929 | */ | |
2878dffc CB |
930 | if (ovl_dentry_upper(dentry)) |
931 | ovl_copyattr(d_inode(dentry)); | |
d9854c87 | 932 | |
e9be9d5e | 933 | out: |
6d0a8a90 | 934 | ovl_cache_free(&list); |
e9be9d5e MS |
935 | return err; |
936 | } | |
937 | ||
938 | static int ovl_unlink(struct inode *dir, struct dentry *dentry) | |
939 | { | |
940 | return ovl_do_remove(dentry, false); | |
941 | } | |
942 | ||
943 | static int ovl_rmdir(struct inode *dir, struct dentry *dentry) | |
944 | { | |
945 | return ovl_do_remove(dentry, true); | |
946 | } | |
947 | ||
370e55ac MS |
948 | static bool ovl_type_merge_or_lower(struct dentry *dentry) |
949 | { | |
950 | enum ovl_path_type type = ovl_path_type(dentry); | |
951 | ||
952 | return OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type); | |
953 | } | |
954 | ||
a6c60655 MS |
955 | static bool ovl_can_move(struct dentry *dentry) |
956 | { | |
af5f2396 | 957 | return ovl_redirect_dir(OVL_FS(dentry->d_sb)) || |
a6c60655 MS |
958 | !d_is_dir(dentry) || !ovl_type_merge_or_lower(dentry); |
959 | } | |
960 | ||
7bb08383 | 961 | static char *ovl_get_redirect(struct dentry *dentry, bool abs_redirect) |
a6c60655 MS |
962 | { |
963 | char *buf, *ret; | |
964 | struct dentry *d, *tmp; | |
3ea22a71 | 965 | int buflen = ovl_redirect_max + 1; |
a6c60655 | 966 | |
7bb08383 | 967 | if (!abs_redirect) { |
a6c60655 MS |
968 | ret = kstrndup(dentry->d_name.name, dentry->d_name.len, |
969 | GFP_KERNEL); | |
970 | goto out; | |
971 | } | |
972 | ||
0ee931c4 | 973 | buf = ret = kmalloc(buflen, GFP_KERNEL); |
a6c60655 MS |
974 | if (!buf) |
975 | goto out; | |
976 | ||
977 | buflen--; | |
978 | buf[buflen] = '\0'; | |
979 | for (d = dget(dentry); !IS_ROOT(d);) { | |
980 | const char *name; | |
981 | int thislen; | |
982 | ||
983 | spin_lock(&d->d_lock); | |
984 | name = ovl_dentry_get_redirect(d); | |
985 | if (name) { | |
986 | thislen = strlen(name); | |
987 | } else { | |
988 | name = d->d_name.name; | |
989 | thislen = d->d_name.len; | |
990 | } | |
991 | ||
992 | /* If path is too long, fall back to userspace move */ | |
993 | if (thislen + (name[0] != '/') > buflen) { | |
994 | ret = ERR_PTR(-EXDEV); | |
995 | spin_unlock(&d->d_lock); | |
996 | goto out_put; | |
997 | } | |
998 | ||
999 | buflen -= thislen; | |
1000 | memcpy(&buf[buflen], name, thislen); | |
a6c60655 | 1001 | spin_unlock(&d->d_lock); |
e04527fe | 1002 | tmp = dget_parent(d); |
a6c60655 MS |
1003 | |
1004 | dput(d); | |
1005 | d = tmp; | |
1006 | ||
1007 | /* Absolute redirect: finished */ | |
1008 | if (buf[buflen] == '/') | |
1009 | break; | |
1010 | buflen--; | |
1011 | buf[buflen] = '/'; | |
1012 | } | |
1013 | ret = kstrdup(&buf[buflen], GFP_KERNEL); | |
1014 | out_put: | |
1015 | dput(d); | |
1016 | kfree(buf); | |
1017 | out: | |
1018 | return ret ? ret : ERR_PTR(-ENOMEM); | |
1019 | } | |
1020 | ||
7bb08383 VG |
1021 | static bool ovl_need_absolute_redirect(struct dentry *dentry, bool samedir) |
1022 | { | |
1023 | struct dentry *lowerdentry; | |
1024 | ||
1025 | if (!samedir) | |
1026 | return true; | |
1027 | ||
1028 | if (d_is_dir(dentry)) | |
1029 | return false; | |
1030 | ||
1031 | /* | |
1032 | * For non-dir hardlinked files, we need absolute redirects | |
1033 | * in general as two upper hardlinks could be in different | |
1034 | * dirs. We could put a relative redirect now and convert | |
1035 | * it to absolute redirect later. But when nlink > 1 and | |
1036 | * indexing is on, that means relative redirect needs to be | |
1037 | * converted to absolute during copy up of another lower | |
1038 | * hardllink as well. | |
1039 | * | |
1040 | * So without optimizing too much, just check if lower is | |
1041 | * a hard link or not. If lower is hard link, put absolute | |
1042 | * redirect. | |
1043 | */ | |
1044 | lowerdentry = ovl_dentry_lower(dentry); | |
1045 | return (d_inode(lowerdentry)->i_nlink > 1); | |
1046 | } | |
1047 | ||
a6c60655 MS |
1048 | static int ovl_set_redirect(struct dentry *dentry, bool samedir) |
1049 | { | |
1050 | int err; | |
a0c236b1 | 1051 | struct ovl_fs *ofs = OVL_FS(dentry->d_sb); |
a6c60655 | 1052 | const char *redirect = ovl_dentry_get_redirect(dentry); |
7bb08383 | 1053 | bool absolute_redirect = ovl_need_absolute_redirect(dentry, samedir); |
a6c60655 | 1054 | |
7bb08383 | 1055 | if (redirect && (!absolute_redirect || redirect[0] == '/')) |
a6c60655 MS |
1056 | return 0; |
1057 | ||
7bb08383 | 1058 | redirect = ovl_get_redirect(dentry, absolute_redirect); |
a6c60655 MS |
1059 | if (IS_ERR(redirect)) |
1060 | return PTR_ERR(redirect); | |
1061 | ||
a0c236b1 | 1062 | err = ovl_check_setxattr(ofs, ovl_dentry_upper(dentry), |
21a22878 AG |
1063 | OVL_XATTR_REDIRECT, |
1064 | redirect, strlen(redirect), -EXDEV); | |
a6c60655 MS |
1065 | if (!err) { |
1066 | spin_lock(&dentry->d_lock); | |
1067 | ovl_dentry_set_redirect(dentry, redirect); | |
1068 | spin_unlock(&dentry->d_lock); | |
1069 | } else { | |
1070 | kfree(redirect); | |
1bd0a3ae | 1071 | pr_warn_ratelimited("failed to set redirect (%i)\n", |
da2e6b7e | 1072 | err); |
a6c60655 MS |
1073 | /* Fall back to userspace copy-up */ |
1074 | err = -EXDEV; | |
1075 | } | |
1076 | return err; | |
1077 | } | |
1078 | ||
e18275ae | 1079 | static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, |
549c7297 CB |
1080 | struct dentry *old, struct inode *newdir, |
1081 | struct dentry *new, unsigned int flags) | |
e9be9d5e MS |
1082 | { |
1083 | int err; | |
e9be9d5e MS |
1084 | struct dentry *old_upperdir; |
1085 | struct dentry *new_upperdir; | |
1086 | struct dentry *olddentry; | |
1087 | struct dentry *newdentry; | |
1088 | struct dentry *trap; | |
1089 | bool old_opaque; | |
1090 | bool new_opaque; | |
e9be9d5e | 1091 | bool cleanup_whiteout = false; |
0e32992f | 1092 | bool update_nlink = false; |
e9be9d5e | 1093 | bool overwrite = !(flags & RENAME_EXCHANGE); |
e36cb0b8 | 1094 | bool is_dir = d_is_dir(old); |
370e55ac | 1095 | bool new_is_dir = d_is_dir(new); |
a6c60655 | 1096 | bool samedir = olddir == newdir; |
e9be9d5e MS |
1097 | struct dentry *opaquedir = NULL; |
1098 | const struct cred *old_cred = NULL; | |
576bb263 | 1099 | struct ovl_fs *ofs = OVL_FS(old->d_sb); |
6d0a8a90 | 1100 | LIST_HEAD(list); |
e9be9d5e MS |
1101 | |
1102 | err = -EINVAL; | |
1103 | if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) | |
1104 | goto out; | |
1105 | ||
1106 | flags &= ~RENAME_NOREPLACE; | |
1107 | ||
e9be9d5e | 1108 | /* Don't copy up directory trees */ |
e9be9d5e | 1109 | err = -EXDEV; |
a6c60655 | 1110 | if (!ovl_can_move(old)) |
370e55ac | 1111 | goto out; |
a6c60655 | 1112 | if (!overwrite && !ovl_can_move(new)) |
e9be9d5e | 1113 | goto out; |
e9be9d5e | 1114 | |
6d0a8a90 AG |
1115 | if (overwrite && new_is_dir && !ovl_pure_upper(new)) { |
1116 | err = ovl_check_empty_dir(new, &list); | |
1117 | if (err) | |
1118 | goto out; | |
1119 | } | |
1120 | ||
1121 | if (overwrite) { | |
1122 | if (ovl_lower_positive(old)) { | |
1123 | if (!ovl_dentry_is_whiteout(new)) { | |
1124 | /* Whiteout source */ | |
1125 | flags |= RENAME_WHITEOUT; | |
1126 | } else { | |
1127 | /* Switch whiteouts */ | |
1128 | flags |= RENAME_EXCHANGE; | |
1129 | } | |
1130 | } else if (is_dir && ovl_dentry_is_whiteout(new)) { | |
1131 | flags |= RENAME_EXCHANGE; | |
1132 | cleanup_whiteout = true; | |
1133 | } | |
1134 | } | |
1135 | ||
e9be9d5e MS |
1136 | err = ovl_copy_up(old); |
1137 | if (err) | |
162d0644 | 1138 | goto out; |
e9be9d5e MS |
1139 | |
1140 | err = ovl_copy_up(new->d_parent); | |
1141 | if (err) | |
162d0644 | 1142 | goto out; |
e9be9d5e MS |
1143 | if (!overwrite) { |
1144 | err = ovl_copy_up(new); | |
1145 | if (err) | |
162d0644 | 1146 | goto out; |
0e32992f AG |
1147 | } else if (d_inode(new)) { |
1148 | err = ovl_nlink_start(new); | |
5f8415d6 | 1149 | if (err) |
162d0644 | 1150 | goto out; |
0e32992f AG |
1151 | |
1152 | update_nlink = true; | |
e9be9d5e MS |
1153 | } |
1154 | ||
162d0644 AG |
1155 | if (!update_nlink) { |
1156 | /* ovl_nlink_start() took ovl_want_write() */ | |
1157 | err = ovl_want_write(old); | |
1158 | if (err) | |
1159 | goto out; | |
1160 | } | |
1161 | ||
1175b6b8 | 1162 | old_cred = ovl_override_creds(old->d_sb); |
e9be9d5e | 1163 | |
6d0a8a90 AG |
1164 | if (!list_empty(&list)) { |
1165 | opaquedir = ovl_clear_empty(new, &list); | |
e9be9d5e MS |
1166 | err = PTR_ERR(opaquedir); |
1167 | if (IS_ERR(opaquedir)) { | |
1168 | opaquedir = NULL; | |
1169 | goto out_revert_creds; | |
1170 | } | |
1171 | } | |
1172 | ||
e9be9d5e MS |
1173 | old_upperdir = ovl_dentry_upper(old->d_parent); |
1174 | new_upperdir = ovl_dentry_upper(new->d_parent); | |
1175 | ||
ee1d6d37 AG |
1176 | if (!samedir) { |
1177 | /* | |
1178 | * When moving a merge dir or non-dir with copy up origin into | |
f3a15685 AG |
1179 | * a new parent, we are marking the new parent dir "impure". |
1180 | * When ovl_iterate() iterates an "impure" upper dir, it will | |
1181 | * lookup the origin inodes of the entries to fill d_ino. | |
ee1d6d37 | 1182 | */ |
f3a15685 | 1183 | if (ovl_type_origin(old)) { |
ee1d6d37 AG |
1184 | err = ovl_set_impure(new->d_parent, new_upperdir); |
1185 | if (err) | |
1186 | goto out_revert_creds; | |
1187 | } | |
f3a15685 | 1188 | if (!overwrite && ovl_type_origin(new)) { |
ee1d6d37 AG |
1189 | err = ovl_set_impure(old->d_parent, old_upperdir); |
1190 | if (err) | |
1191 | goto out_revert_creds; | |
1192 | } | |
1193 | } | |
1194 | ||
e9be9d5e | 1195 | trap = lock_rename(new_upperdir, old_upperdir); |
a8b00268 AV |
1196 | if (IS_ERR(trap)) { |
1197 | err = PTR_ERR(trap); | |
1198 | goto out_revert_creds; | |
1199 | } | |
e9be9d5e | 1200 | |
22f289ce CB |
1201 | olddentry = ovl_lookup_upper(ofs, old->d_name.name, old_upperdir, |
1202 | old->d_name.len); | |
11f37104 MS |
1203 | err = PTR_ERR(olddentry); |
1204 | if (IS_ERR(olddentry)) | |
1205 | goto out_unlock; | |
1206 | ||
1207 | err = -ESTALE; | |
9020df37 | 1208 | if (!ovl_matches_upper(old, olddentry)) |
11f37104 MS |
1209 | goto out_dput_old; |
1210 | ||
22f289ce CB |
1211 | newdentry = ovl_lookup_upper(ofs, new->d_name.name, new_upperdir, |
1212 | new->d_name.len); | |
11f37104 MS |
1213 | err = PTR_ERR(newdentry); |
1214 | if (IS_ERR(newdentry)) | |
1215 | goto out_dput_old; | |
1216 | ||
3ee23ff1 MS |
1217 | old_opaque = ovl_dentry_is_opaque(old); |
1218 | new_opaque = ovl_dentry_is_opaque(new); | |
1219 | ||
11f37104 | 1220 | err = -ESTALE; |
09d8b586 | 1221 | if (d_inode(new) && ovl_dentry_upper(new)) { |
e9be9d5e | 1222 | if (opaquedir) { |
11f37104 MS |
1223 | if (newdentry != opaquedir) |
1224 | goto out_dput; | |
e9be9d5e | 1225 | } else { |
9020df37 | 1226 | if (!ovl_matches_upper(new, newdentry)) |
11f37104 | 1227 | goto out_dput; |
e9be9d5e MS |
1228 | } |
1229 | } else { | |
a295aef6 | 1230 | if (!d_is_negative(newdentry)) { |
bc8df7a3 | 1231 | if (!new_opaque || !ovl_upper_is_whiteout(ofs, newdentry)) |
a295aef6 ZL |
1232 | goto out_dput; |
1233 | } else { | |
1234 | if (flags & RENAME_EXCHANGE) | |
1235 | goto out_dput; | |
1236 | } | |
e9be9d5e MS |
1237 | } |
1238 | ||
e9be9d5e MS |
1239 | if (olddentry == trap) |
1240 | goto out_dput; | |
1241 | if (newdentry == trap) | |
1242 | goto out_dput; | |
1243 | ||
6889ee5a | 1244 | if (olddentry->d_inode == newdentry->d_inode) |
804032fa MS |
1245 | goto out_dput; |
1246 | ||
5cf5b477 | 1247 | err = 0; |
7bb08383 VG |
1248 | if (ovl_type_merge_or_lower(old)) |
1249 | err = ovl_set_redirect(old, samedir); | |
1250 | else if (is_dir && !old_opaque && ovl_type_merge(new->d_parent)) | |
1251 | err = ovl_set_opaque_xerr(old, olddentry, -EXDEV); | |
1252 | if (err) | |
1253 | goto out_dput; | |
1254 | ||
1255 | if (!overwrite && ovl_type_merge_or_lower(new)) | |
1256 | err = ovl_set_redirect(new, samedir); | |
1257 | else if (!overwrite && new_is_dir && !new_opaque && | |
1258 | ovl_type_merge(old->d_parent)) | |
1259 | err = ovl_set_opaque_xerr(new, newdentry, -EXDEV); | |
1260 | if (err) | |
1261 | goto out_dput; | |
e9be9d5e | 1262 | |
576bb263 | 1263 | err = ovl_do_rename(ofs, old_upperdir->d_inode, olddentry, |
3ee23ff1 MS |
1264 | new_upperdir->d_inode, newdentry, flags); |
1265 | if (err) | |
e9be9d5e | 1266 | goto out_dput; |
e9be9d5e MS |
1267 | |
1268 | if (cleanup_whiteout) | |
576bb263 | 1269 | ovl_cleanup(ofs, old_upperdir->d_inode, newdentry); |
e9be9d5e | 1270 | |
f681eb1d AG |
1271 | if (overwrite && d_inode(new)) { |
1272 | if (new_is_dir) | |
1273 | clear_nlink(d_inode(new)); | |
1274 | else | |
83552eac | 1275 | ovl_drop_nlink(new); |
f681eb1d AG |
1276 | } |
1277 | ||
d9854c87 MS |
1278 | ovl_dir_modified(old->d_parent, ovl_type_origin(old) || |
1279 | (!overwrite && ovl_type_origin(new))); | |
1280 | ovl_dir_modified(new->d_parent, ovl_type_origin(old) || | |
1281 | (d_inode(new) && ovl_type_origin(new))); | |
1282 | ||
1283 | /* copy ctime: */ | |
2878dffc | 1284 | ovl_copyattr(d_inode(old)); |
d9854c87 | 1285 | if (d_inode(new) && ovl_dentry_upper(new)) |
2878dffc | 1286 | ovl_copyattr(d_inode(new)); |
e9be9d5e MS |
1287 | |
1288 | out_dput: | |
1289 | dput(newdentry); | |
11f37104 MS |
1290 | out_dput_old: |
1291 | dput(olddentry); | |
e9be9d5e MS |
1292 | out_unlock: |
1293 | unlock_rename(new_upperdir, old_upperdir); | |
1294 | out_revert_creds: | |
1175b6b8 | 1295 | revert_creds(old_cred); |
0e32992f AG |
1296 | if (update_nlink) |
1297 | ovl_nlink_end(new); | |
162d0644 AG |
1298 | else |
1299 | ovl_drop_write(old); | |
e9be9d5e MS |
1300 | out: |
1301 | dput(opaquedir); | |
6d0a8a90 | 1302 | ovl_cache_free(&list); |
e9be9d5e MS |
1303 | return err; |
1304 | } | |
1305 | ||
9a87907d MS |
1306 | static int ovl_create_tmpfile(struct file *file, struct dentry *dentry, |
1307 | struct inode *inode, umode_t mode) | |
1308 | { | |
1309 | const struct cred *old_cred; | |
1310 | struct path realparentpath; | |
1311 | struct file *realfile; | |
1312 | struct dentry *newdentry; | |
1313 | /* It's okay to set O_NOATIME, since the owner will be current fsuid */ | |
1314 | int flags = file->f_flags | OVL_OPEN_FLAGS; | |
1315 | int err; | |
1316 | ||
9a87907d MS |
1317 | old_cred = ovl_override_creds(dentry->d_sb); |
1318 | err = ovl_setup_cred_for_create(dentry, inode, mode, old_cred); | |
1319 | if (err) | |
1320 | goto out_revert_creds; | |
1321 | ||
1322 | ovl_path_upper(dentry->d_parent, &realparentpath); | |
1323 | realfile = backing_tmpfile_open(&file->f_path, flags, &realparentpath, | |
1324 | mode, current_cred()); | |
1325 | err = PTR_ERR_OR_ZERO(realfile); | |
1326 | pr_debug("tmpfile/open(%pd2, 0%o) = %i\n", realparentpath.dentry, mode, err); | |
1327 | if (err) | |
1328 | goto out_revert_creds; | |
1329 | ||
1330 | /* ovl_instantiate() consumes the newdentry reference on success */ | |
1331 | newdentry = dget(realfile->f_path.dentry); | |
1332 | err = ovl_instantiate(dentry, inode, newdentry, false, file); | |
1333 | if (!err) { | |
1334 | file->private_data = realfile; | |
1335 | } else { | |
1336 | dput(newdentry); | |
1337 | fput(realfile); | |
1338 | } | |
1339 | out_revert_creds: | |
1340 | revert_creds(old_cred); | |
1341 | return err; | |
1342 | } | |
1343 | ||
1344 | static int ovl_dummy_open(struct inode *inode, struct file *file) | |
1345 | { | |
1346 | return 0; | |
1347 | } | |
1348 | ||
1349 | static int ovl_tmpfile(struct mnt_idmap *idmap, struct inode *dir, | |
1350 | struct file *file, umode_t mode) | |
1351 | { | |
1352 | int err; | |
1353 | struct dentry *dentry = file->f_path.dentry; | |
1354 | struct inode *inode; | |
1355 | ||
1356 | if (!OVL_FS(dentry->d_sb)->tmpfile) | |
1357 | return -EOPNOTSUPP; | |
1358 | ||
db03d390 MS |
1359 | err = ovl_copy_up(dentry->d_parent); |
1360 | if (err) | |
1361 | return err; | |
1362 | ||
9a87907d MS |
1363 | err = ovl_want_write(dentry); |
1364 | if (err) | |
1365 | return err; | |
1366 | ||
1367 | err = -ENOMEM; | |
1368 | inode = ovl_new_inode(dentry->d_sb, mode, 0); | |
1369 | if (!inode) | |
1370 | goto drop_write; | |
1371 | ||
1372 | inode_init_owner(&nop_mnt_idmap, inode, dir, mode); | |
1373 | err = ovl_create_tmpfile(file, dentry, inode, inode->i_mode); | |
1374 | if (err) | |
1375 | goto put_inode; | |
1376 | ||
1377 | /* | |
1378 | * Check if the preallocated inode was actually used. Having something | |
1379 | * else assigned to the dentry shouldn't happen as that would indicate | |
1380 | * that the backing tmpfile "leaked" out of overlayfs. | |
1381 | */ | |
1382 | err = -EIO; | |
1383 | if (WARN_ON(inode != d_inode(dentry))) | |
1384 | goto put_realfile; | |
1385 | ||
1386 | /* inode reference was transferred to dentry */ | |
1387 | inode = NULL; | |
1388 | err = finish_open(file, dentry, ovl_dummy_open); | |
1389 | put_realfile: | |
1390 | /* Without FMODE_OPENED ->release() won't be called on @file */ | |
1391 | if (!(file->f_mode & FMODE_OPENED)) | |
1392 | fput(file->private_data); | |
1393 | put_inode: | |
1394 | iput(inode); | |
1395 | drop_write: | |
1396 | ovl_drop_write(dentry); | |
1397 | return err; | |
1398 | } | |
1399 | ||
e9be9d5e MS |
1400 | const struct inode_operations ovl_dir_inode_operations = { |
1401 | .lookup = ovl_lookup, | |
1402 | .mkdir = ovl_mkdir, | |
1403 | .symlink = ovl_symlink, | |
1404 | .unlink = ovl_unlink, | |
1405 | .rmdir = ovl_rmdir, | |
6c02cb59 | 1406 | .rename = ovl_rename, |
e9be9d5e MS |
1407 | .link = ovl_link, |
1408 | .setattr = ovl_setattr, | |
1409 | .create = ovl_create, | |
1410 | .mknod = ovl_mknod, | |
1411 | .permission = ovl_permission, | |
5b712091 | 1412 | .getattr = ovl_getattr, |
e9be9d5e | 1413 | .listxattr = ovl_listxattr, |
6c0a8bfb CB |
1414 | .get_inode_acl = ovl_get_inode_acl, |
1415 | .get_acl = ovl_get_acl, | |
0e641857 | 1416 | .set_acl = ovl_set_acl, |
d719e8f2 | 1417 | .update_time = ovl_update_time, |
66dbfabf MS |
1418 | .fileattr_get = ovl_fileattr_get, |
1419 | .fileattr_set = ovl_fileattr_set, | |
9a87907d | 1420 | .tmpfile = ovl_tmpfile, |
e9be9d5e | 1421 | }; |