Commit | Line | Data |
---|---|---|
e9be9d5e MS |
1 | /* |
2 | * | |
3 | * Copyright (C) 2011 Novell Inc. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License version 2 as published by | |
7 | * the Free Software Foundation. | |
8 | */ | |
9 | ||
10 | #include <linux/fs.h> | |
11 | #include <linux/namei.h> | |
cf9a6784 | 12 | #include <linux/pagemap.h> |
e9be9d5e MS |
13 | #include <linux/xattr.h> |
14 | #include <linux/security.h> | |
15 | #include <linux/mount.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/parser.h> | |
18 | #include <linux/module.h> | |
e458bcd1 | 19 | #include <linux/pagemap.h> |
e9be9d5e | 20 | #include <linux/sched.h> |
cc259639 | 21 | #include <linux/statfs.h> |
f45827e8 | 22 | #include <linux/seq_file.h> |
e9be9d5e MS |
23 | #include "overlayfs.h" |
24 | ||
25 | MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); | |
26 | MODULE_DESCRIPTION("Overlay filesystem"); | |
27 | MODULE_LICENSE("GPL"); | |
28 | ||
f45827e8 EZ |
29 | struct ovl_config { |
30 | char *lowerdir; | |
31 | char *upperdir; | |
32 | char *workdir; | |
8d3095f4 | 33 | bool default_permissions; |
f45827e8 EZ |
34 | }; |
35 | ||
e9be9d5e MS |
36 | /* private information held for overlayfs's superblock */ |
37 | struct ovl_fs { | |
38 | struct vfsmount *upper_mnt; | |
dd662667 MS |
39 | unsigned numlower; |
40 | struct vfsmount **lower_mnt; | |
e9be9d5e | 41 | struct dentry *workdir; |
cc259639 | 42 | long lower_namelen; |
f45827e8 EZ |
43 | /* pathnames of lower and upper dirs, for show_options */ |
44 | struct ovl_config config; | |
e9be9d5e MS |
45 | }; |
46 | ||
47 | struct ovl_dir_cache; | |
48 | ||
49 | /* private information held for every overlayfs dentry */ | |
50 | struct ovl_entry { | |
51 | struct dentry *__upperdentry; | |
e9be9d5e MS |
52 | struct ovl_dir_cache *cache; |
53 | union { | |
54 | struct { | |
55 | u64 version; | |
56 | bool opaque; | |
57 | }; | |
58 | struct rcu_head rcu; | |
59 | }; | |
dd662667 MS |
60 | unsigned numlower; |
61 | struct path lowerstack[]; | |
e9be9d5e MS |
62 | }; |
63 | ||
a78d9f0d MS |
64 | #define OVL_MAX_STACK 500 |
65 | ||
dd662667 MS |
66 | static struct dentry *__ovl_dentry_lower(struct ovl_entry *oe) |
67 | { | |
68 | return oe->numlower ? oe->lowerstack[0].dentry : NULL; | |
69 | } | |
e9be9d5e MS |
70 | |
71 | enum ovl_path_type ovl_path_type(struct dentry *dentry) | |
72 | { | |
73 | struct ovl_entry *oe = dentry->d_fsdata; | |
1afaba1e | 74 | enum ovl_path_type type = 0; |
e9be9d5e MS |
75 | |
76 | if (oe->__upperdentry) { | |
1afaba1e MS |
77 | type = __OVL_PATH_UPPER; |
78 | ||
45d11738 KK |
79 | /* |
80 | * Non-dir dentry can hold lower dentry from previous | |
81 | * location. Its purity depends only on opaque flag. | |
82 | */ | |
83 | if (oe->numlower && S_ISDIR(dentry->d_inode->i_mode)) | |
84 | type |= __OVL_PATH_MERGE; | |
85 | else if (!oe->opaque) | |
1afaba1e | 86 | type |= __OVL_PATH_PURE; |
9d7459d8 MS |
87 | } else { |
88 | if (oe->numlower > 1) | |
89 | type |= __OVL_PATH_MERGE; | |
e9be9d5e | 90 | } |
1afaba1e | 91 | return type; |
e9be9d5e MS |
92 | } |
93 | ||
94 | static struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe) | |
95 | { | |
71d50928 | 96 | return lockless_dereference(oe->__upperdentry); |
e9be9d5e MS |
97 | } |
98 | ||
99 | void ovl_path_upper(struct dentry *dentry, struct path *path) | |
100 | { | |
101 | struct ovl_fs *ofs = dentry->d_sb->s_fs_info; | |
102 | struct ovl_entry *oe = dentry->d_fsdata; | |
103 | ||
104 | path->mnt = ofs->upper_mnt; | |
105 | path->dentry = ovl_upperdentry_dereference(oe); | |
106 | } | |
107 | ||
108 | enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) | |
109 | { | |
e9be9d5e MS |
110 | enum ovl_path_type type = ovl_path_type(dentry); |
111 | ||
1afaba1e | 112 | if (!OVL_TYPE_UPPER(type)) |
e9be9d5e MS |
113 | ovl_path_lower(dentry, path); |
114 | else | |
115 | ovl_path_upper(dentry, path); | |
116 | ||
117 | return type; | |
118 | } | |
119 | ||
120 | struct dentry *ovl_dentry_upper(struct dentry *dentry) | |
121 | { | |
122 | struct ovl_entry *oe = dentry->d_fsdata; | |
123 | ||
124 | return ovl_upperdentry_dereference(oe); | |
125 | } | |
126 | ||
127 | struct dentry *ovl_dentry_lower(struct dentry *dentry) | |
128 | { | |
129 | struct ovl_entry *oe = dentry->d_fsdata; | |
130 | ||
dd662667 | 131 | return __ovl_dentry_lower(oe); |
e9be9d5e MS |
132 | } |
133 | ||
134 | struct dentry *ovl_dentry_real(struct dentry *dentry) | |
135 | { | |
136 | struct ovl_entry *oe = dentry->d_fsdata; | |
137 | struct dentry *realdentry; | |
138 | ||
139 | realdentry = ovl_upperdentry_dereference(oe); | |
140 | if (!realdentry) | |
dd662667 | 141 | realdentry = __ovl_dentry_lower(oe); |
e9be9d5e MS |
142 | |
143 | return realdentry; | |
144 | } | |
145 | ||
146 | struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper) | |
147 | { | |
148 | struct dentry *realdentry; | |
149 | ||
150 | realdentry = ovl_upperdentry_dereference(oe); | |
151 | if (realdentry) { | |
152 | *is_upper = true; | |
153 | } else { | |
dd662667 | 154 | realdentry = __ovl_dentry_lower(oe); |
e9be9d5e MS |
155 | *is_upper = false; |
156 | } | |
157 | return realdentry; | |
158 | } | |
159 | ||
8d3095f4 MS |
160 | struct vfsmount *ovl_entry_mnt_real(struct ovl_entry *oe, struct inode *inode, |
161 | bool is_upper) | |
162 | { | |
163 | if (is_upper) { | |
164 | struct ovl_fs *ofs = inode->i_sb->s_fs_info; | |
165 | ||
166 | return ofs->upper_mnt; | |
167 | } else { | |
168 | return oe->numlower ? oe->lowerstack[0].mnt : NULL; | |
169 | } | |
170 | } | |
171 | ||
e9be9d5e MS |
172 | struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry) |
173 | { | |
174 | struct ovl_entry *oe = dentry->d_fsdata; | |
175 | ||
176 | return oe->cache; | |
177 | } | |
178 | ||
8d3095f4 MS |
179 | bool ovl_is_default_permissions(struct inode *inode) |
180 | { | |
181 | struct ovl_fs *ofs = inode->i_sb->s_fs_info; | |
182 | ||
183 | return ofs->config.default_permissions; | |
184 | } | |
185 | ||
e9be9d5e MS |
186 | void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache) |
187 | { | |
188 | struct ovl_entry *oe = dentry->d_fsdata; | |
189 | ||
190 | oe->cache = cache; | |
191 | } | |
192 | ||
193 | void ovl_path_lower(struct dentry *dentry, struct path *path) | |
194 | { | |
e9be9d5e MS |
195 | struct ovl_entry *oe = dentry->d_fsdata; |
196 | ||
dd662667 | 197 | *path = oe->numlower ? oe->lowerstack[0] : (struct path) { NULL, NULL }; |
e9be9d5e MS |
198 | } |
199 | ||
200 | int ovl_want_write(struct dentry *dentry) | |
201 | { | |
202 | struct ovl_fs *ofs = dentry->d_sb->s_fs_info; | |
203 | return mnt_want_write(ofs->upper_mnt); | |
204 | } | |
205 | ||
206 | void ovl_drop_write(struct dentry *dentry) | |
207 | { | |
208 | struct ovl_fs *ofs = dentry->d_sb->s_fs_info; | |
209 | mnt_drop_write(ofs->upper_mnt); | |
210 | } | |
211 | ||
212 | struct dentry *ovl_workdir(struct dentry *dentry) | |
213 | { | |
214 | struct ovl_fs *ofs = dentry->d_sb->s_fs_info; | |
215 | return ofs->workdir; | |
216 | } | |
217 | ||
218 | bool ovl_dentry_is_opaque(struct dentry *dentry) | |
219 | { | |
220 | struct ovl_entry *oe = dentry->d_fsdata; | |
221 | return oe->opaque; | |
222 | } | |
223 | ||
224 | void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque) | |
225 | { | |
226 | struct ovl_entry *oe = dentry->d_fsdata; | |
227 | oe->opaque = opaque; | |
228 | } | |
229 | ||
230 | void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry) | |
231 | { | |
232 | struct ovl_entry *oe = dentry->d_fsdata; | |
233 | ||
5955102c | 234 | WARN_ON(!inode_is_locked(upperdentry->d_parent->d_inode)); |
e9be9d5e MS |
235 | WARN_ON(oe->__upperdentry); |
236 | BUG_ON(!upperdentry->d_inode); | |
237 | /* | |
238 | * Make sure upperdentry is consistent before making it visible to | |
239 | * ovl_upperdentry_dereference(). | |
240 | */ | |
241 | smp_wmb(); | |
242 | oe->__upperdentry = upperdentry; | |
243 | } | |
244 | ||
245 | void ovl_dentry_version_inc(struct dentry *dentry) | |
246 | { | |
247 | struct ovl_entry *oe = dentry->d_fsdata; | |
248 | ||
5955102c | 249 | WARN_ON(!inode_is_locked(dentry->d_inode)); |
e9be9d5e MS |
250 | oe->version++; |
251 | } | |
252 | ||
253 | u64 ovl_dentry_version_get(struct dentry *dentry) | |
254 | { | |
255 | struct ovl_entry *oe = dentry->d_fsdata; | |
256 | ||
5955102c | 257 | WARN_ON(!inode_is_locked(dentry->d_inode)); |
e9be9d5e MS |
258 | return oe->version; |
259 | } | |
260 | ||
261 | bool ovl_is_whiteout(struct dentry *dentry) | |
262 | { | |
263 | struct inode *inode = dentry->d_inode; | |
264 | ||
265 | return inode && IS_WHITEOUT(inode); | |
266 | } | |
267 | ||
268 | static bool ovl_is_opaquedir(struct dentry *dentry) | |
269 | { | |
270 | int res; | |
271 | char val; | |
272 | struct inode *inode = dentry->d_inode; | |
273 | ||
274 | if (!S_ISDIR(inode->i_mode) || !inode->i_op->getxattr) | |
275 | return false; | |
276 | ||
cead89bb | 277 | res = inode->i_op->getxattr(dentry, OVL_XATTR_OPAQUE, &val, 1); |
e9be9d5e MS |
278 | if (res == 1 && val == 'y') |
279 | return true; | |
280 | ||
281 | return false; | |
282 | } | |
283 | ||
284 | static void ovl_dentry_release(struct dentry *dentry) | |
285 | { | |
286 | struct ovl_entry *oe = dentry->d_fsdata; | |
287 | ||
288 | if (oe) { | |
dd662667 MS |
289 | unsigned int i; |
290 | ||
e9be9d5e | 291 | dput(oe->__upperdentry); |
dd662667 MS |
292 | for (i = 0; i < oe->numlower; i++) |
293 | dput(oe->lowerstack[i].dentry); | |
e9be9d5e MS |
294 | kfree_rcu(oe, rcu); |
295 | } | |
296 | } | |
297 | ||
d101a125 MS |
298 | static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode) |
299 | { | |
300 | struct dentry *real; | |
301 | ||
302 | if (d_is_dir(dentry)) { | |
303 | if (!inode || inode == d_inode(dentry)) | |
304 | return dentry; | |
305 | goto bug; | |
306 | } | |
307 | ||
308 | real = ovl_dentry_upper(dentry); | |
309 | if (real && (!inode || inode == d_inode(real))) | |
310 | return real; | |
311 | ||
312 | real = ovl_dentry_lower(dentry); | |
313 | if (!real) | |
314 | goto bug; | |
315 | ||
316 | if (!inode || inode == d_inode(real)) | |
317 | return real; | |
318 | ||
319 | /* Handle recursion */ | |
320 | if (real->d_flags & DCACHE_OP_REAL) | |
321 | return real->d_op->d_real(real, inode); | |
322 | ||
323 | bug: | |
324 | WARN(1, "ovl_d_real(%pd4, %s:%lu\n): real dentry not found\n", dentry, | |
325 | inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0); | |
326 | return dentry; | |
327 | } | |
328 | ||
7c03b5d4 MS |
329 | static int ovl_dentry_revalidate(struct dentry *dentry, unsigned int flags) |
330 | { | |
331 | struct ovl_entry *oe = dentry->d_fsdata; | |
332 | unsigned int i; | |
333 | int ret = 1; | |
334 | ||
335 | for (i = 0; i < oe->numlower; i++) { | |
336 | struct dentry *d = oe->lowerstack[i].dentry; | |
337 | ||
338 | if (d->d_flags & DCACHE_OP_REVALIDATE) { | |
339 | ret = d->d_op->d_revalidate(d, flags); | |
340 | if (ret < 0) | |
341 | return ret; | |
342 | if (!ret) { | |
343 | if (!(flags & LOOKUP_RCU)) | |
344 | d_invalidate(d); | |
345 | return -ESTALE; | |
346 | } | |
347 | } | |
348 | } | |
349 | return 1; | |
350 | } | |
351 | ||
352 | static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags) | |
353 | { | |
354 | struct ovl_entry *oe = dentry->d_fsdata; | |
355 | unsigned int i; | |
356 | int ret = 1; | |
357 | ||
358 | for (i = 0; i < oe->numlower; i++) { | |
359 | struct dentry *d = oe->lowerstack[i].dentry; | |
360 | ||
361 | if (d->d_flags & DCACHE_OP_WEAK_REVALIDATE) { | |
362 | ret = d->d_op->d_weak_revalidate(d, flags); | |
363 | if (ret <= 0) | |
364 | break; | |
365 | } | |
366 | } | |
367 | return ret; | |
368 | } | |
369 | ||
e9be9d5e MS |
370 | static const struct dentry_operations ovl_dentry_operations = { |
371 | .d_release = ovl_dentry_release, | |
4bacc9c9 | 372 | .d_select_inode = ovl_d_select_inode, |
d101a125 | 373 | .d_real = ovl_d_real, |
e9be9d5e MS |
374 | }; |
375 | ||
7c03b5d4 MS |
376 | static const struct dentry_operations ovl_reval_dentry_operations = { |
377 | .d_release = ovl_dentry_release, | |
b5891cfa | 378 | .d_select_inode = ovl_d_select_inode, |
d101a125 | 379 | .d_real = ovl_d_real, |
7c03b5d4 MS |
380 | .d_revalidate = ovl_dentry_revalidate, |
381 | .d_weak_revalidate = ovl_dentry_weak_revalidate, | |
382 | }; | |
383 | ||
dd662667 | 384 | static struct ovl_entry *ovl_alloc_entry(unsigned int numlower) |
e9be9d5e | 385 | { |
dd662667 MS |
386 | size_t size = offsetof(struct ovl_entry, lowerstack[numlower]); |
387 | struct ovl_entry *oe = kzalloc(size, GFP_KERNEL); | |
388 | ||
389 | if (oe) | |
390 | oe->numlower = numlower; | |
391 | ||
392 | return oe; | |
e9be9d5e MS |
393 | } |
394 | ||
7c03b5d4 MS |
395 | static bool ovl_dentry_remote(struct dentry *dentry) |
396 | { | |
397 | return dentry->d_flags & | |
398 | (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE); | |
399 | } | |
400 | ||
401 | static bool ovl_dentry_weird(struct dentry *dentry) | |
402 | { | |
403 | return dentry->d_flags & (DCACHE_NEED_AUTOMOUNT | | |
404 | DCACHE_MANAGE_TRANSIT | | |
405 | DCACHE_OP_HASH | | |
406 | DCACHE_OP_COMPARE); | |
407 | } | |
408 | ||
e9be9d5e MS |
409 | static inline struct dentry *ovl_lookup_real(struct dentry *dir, |
410 | struct qstr *name) | |
411 | { | |
412 | struct dentry *dentry; | |
413 | ||
38b78a5f | 414 | dentry = lookup_hash(name, dir); |
e9be9d5e MS |
415 | |
416 | if (IS_ERR(dentry)) { | |
417 | if (PTR_ERR(dentry) == -ENOENT) | |
418 | dentry = NULL; | |
419 | } else if (!dentry->d_inode) { | |
420 | dput(dentry); | |
421 | dentry = NULL; | |
7c03b5d4 | 422 | } else if (ovl_dentry_weird(dentry)) { |
a6f15d9a | 423 | dput(dentry); |
7c03b5d4 | 424 | /* Don't support traversing automounts and other weirdness */ |
a6f15d9a | 425 | dentry = ERR_PTR(-EREMOTE); |
e9be9d5e MS |
426 | } |
427 | return dentry; | |
428 | } | |
429 | ||
5ef88da5 MS |
430 | /* |
431 | * Returns next layer in stack starting from top. | |
432 | * Returns -1 if this is the last layer. | |
433 | */ | |
434 | int ovl_path_next(int idx, struct dentry *dentry, struct path *path) | |
435 | { | |
436 | struct ovl_entry *oe = dentry->d_fsdata; | |
437 | ||
438 | BUG_ON(idx < 0); | |
439 | if (idx == 0) { | |
440 | ovl_path_upper(dentry, path); | |
441 | if (path->dentry) | |
442 | return oe->numlower ? 1 : -1; | |
443 | idx++; | |
444 | } | |
445 | BUG_ON(idx > oe->numlower); | |
446 | *path = oe->lowerstack[idx - 1]; | |
447 | ||
448 | return (idx < oe->numlower) ? idx + 1 : -1; | |
449 | } | |
450 | ||
e9be9d5e MS |
451 | struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, |
452 | unsigned int flags) | |
453 | { | |
454 | struct ovl_entry *oe; | |
3d3c6b89 MS |
455 | struct ovl_entry *poe = dentry->d_parent->d_fsdata; |
456 | struct path *stack = NULL; | |
457 | struct dentry *upperdir, *upperdentry = NULL; | |
458 | unsigned int ctr = 0; | |
e9be9d5e | 459 | struct inode *inode = NULL; |
3d3c6b89 MS |
460 | bool upperopaque = false; |
461 | struct dentry *this, *prev = NULL; | |
462 | unsigned int i; | |
e9be9d5e MS |
463 | int err; |
464 | ||
3d3c6b89 | 465 | upperdir = ovl_upperdentry_dereference(poe); |
e9be9d5e | 466 | if (upperdir) { |
3d3c6b89 MS |
467 | this = ovl_lookup_real(upperdir, &dentry->d_name); |
468 | err = PTR_ERR(this); | |
469 | if (IS_ERR(this)) | |
470 | goto out; | |
471 | ||
3e01cee3 | 472 | if (this) { |
7c03b5d4 MS |
473 | if (unlikely(ovl_dentry_remote(this))) { |
474 | dput(this); | |
475 | err = -EREMOTE; | |
476 | goto out; | |
477 | } | |
3d3c6b89 MS |
478 | if (ovl_is_whiteout(this)) { |
479 | dput(this); | |
480 | this = NULL; | |
481 | upperopaque = true; | |
3e01cee3 | 482 | } else if (poe->numlower && ovl_is_opaquedir(this)) { |
3d3c6b89 | 483 | upperopaque = true; |
e9be9d5e MS |
484 | } |
485 | } | |
3d3c6b89 | 486 | upperdentry = prev = this; |
e9be9d5e | 487 | } |
3d3c6b89 MS |
488 | |
489 | if (!upperopaque && poe->numlower) { | |
490 | err = -ENOMEM; | |
491 | stack = kcalloc(poe->numlower, sizeof(struct path), GFP_KERNEL); | |
492 | if (!stack) | |
493 | goto out_put_upper; | |
e9be9d5e MS |
494 | } |
495 | ||
3d3c6b89 MS |
496 | for (i = 0; !upperopaque && i < poe->numlower; i++) { |
497 | bool opaque = false; | |
498 | struct path lowerpath = poe->lowerstack[i]; | |
499 | ||
3d3c6b89 MS |
500 | this = ovl_lookup_real(lowerpath.dentry, &dentry->d_name); |
501 | err = PTR_ERR(this); | |
09e10322 MS |
502 | if (IS_ERR(this)) { |
503 | /* | |
504 | * If it's positive, then treat ENAMETOOLONG as ENOENT. | |
505 | */ | |
506 | if (err == -ENAMETOOLONG && (upperdentry || ctr)) | |
507 | continue; | |
3d3c6b89 | 508 | goto out_put; |
09e10322 | 509 | } |
3d3c6b89 MS |
510 | if (!this) |
511 | continue; | |
3e01cee3 MS |
512 | if (ovl_is_whiteout(this)) { |
513 | dput(this); | |
514 | break; | |
515 | } | |
3d3c6b89 | 516 | /* |
3e01cee3 MS |
517 | * Only makes sense to check opaque dir if this is not the |
518 | * lowermost layer. | |
3d3c6b89 | 519 | */ |
3e01cee3 MS |
520 | if (i < poe->numlower - 1 && ovl_is_opaquedir(this)) |
521 | opaque = true; | |
a425c037 | 522 | |
523 | if (prev && (!S_ISDIR(prev->d_inode->i_mode) || | |
524 | !S_ISDIR(this->d_inode->i_mode))) { | |
525 | /* | |
526 | * FIXME: check for upper-opaqueness maybe better done | |
527 | * in remove code. | |
528 | */ | |
3d3c6b89 MS |
529 | if (prev == upperdentry) |
530 | upperopaque = true; | |
531 | dput(this); | |
532 | break; | |
533 | } | |
a425c037 | 534 | /* |
535 | * If this is a non-directory then stop here. | |
536 | */ | |
537 | if (!S_ISDIR(this->d_inode->i_mode)) | |
538 | opaque = true; | |
539 | ||
3d3c6b89 MS |
540 | stack[ctr].dentry = this; |
541 | stack[ctr].mnt = lowerpath.mnt; | |
542 | ctr++; | |
543 | prev = this; | |
544 | if (opaque) | |
545 | break; | |
e9be9d5e MS |
546 | } |
547 | ||
3d3c6b89 MS |
548 | oe = ovl_alloc_entry(ctr); |
549 | err = -ENOMEM; | |
550 | if (!oe) | |
551 | goto out_put; | |
552 | ||
553 | if (upperdentry || ctr) { | |
e9be9d5e MS |
554 | struct dentry *realdentry; |
555 | ||
3d3c6b89 MS |
556 | realdentry = upperdentry ? upperdentry : stack[0].dentry; |
557 | ||
e9be9d5e MS |
558 | err = -ENOMEM; |
559 | inode = ovl_new_inode(dentry->d_sb, realdentry->d_inode->i_mode, | |
560 | oe); | |
561 | if (!inode) | |
3d3c6b89 | 562 | goto out_free_oe; |
e9be9d5e MS |
563 | ovl_copyattr(realdentry->d_inode, inode); |
564 | } | |
565 | ||
3d3c6b89 | 566 | oe->opaque = upperopaque; |
e9be9d5e | 567 | oe->__upperdentry = upperdentry; |
3d3c6b89 MS |
568 | memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr); |
569 | kfree(stack); | |
e9be9d5e MS |
570 | dentry->d_fsdata = oe; |
571 | d_add(dentry, inode); | |
572 | ||
573 | return NULL; | |
574 | ||
3d3c6b89 | 575 | out_free_oe: |
e9be9d5e | 576 | kfree(oe); |
3d3c6b89 MS |
577 | out_put: |
578 | for (i = 0; i < ctr; i++) | |
579 | dput(stack[i].dentry); | |
580 | kfree(stack); | |
581 | out_put_upper: | |
582 | dput(upperdentry); | |
e9be9d5e MS |
583 | out: |
584 | return ERR_PTR(err); | |
585 | } | |
586 | ||
587 | struct file *ovl_path_open(struct path *path, int flags) | |
588 | { | |
589 | return dentry_open(path, flags, current_cred()); | |
590 | } | |
591 | ||
592 | static void ovl_put_super(struct super_block *sb) | |
593 | { | |
594 | struct ovl_fs *ufs = sb->s_fs_info; | |
dd662667 | 595 | unsigned i; |
e9be9d5e MS |
596 | |
597 | dput(ufs->workdir); | |
598 | mntput(ufs->upper_mnt); | |
dd662667 MS |
599 | for (i = 0; i < ufs->numlower; i++) |
600 | mntput(ufs->lower_mnt[i]); | |
5ffdbe8b | 601 | kfree(ufs->lower_mnt); |
e9be9d5e | 602 | |
f45827e8 EZ |
603 | kfree(ufs->config.lowerdir); |
604 | kfree(ufs->config.upperdir); | |
605 | kfree(ufs->config.workdir); | |
e9be9d5e MS |
606 | kfree(ufs); |
607 | } | |
608 | ||
cc259639 AW |
609 | /** |
610 | * ovl_statfs | |
611 | * @sb: The overlayfs super block | |
612 | * @buf: The struct kstatfs to fill in with stats | |
613 | * | |
614 | * Get the filesystem statistics. As writes always target the upper layer | |
4ebc5818 | 615 | * filesystem pass the statfs to the upper filesystem (if it exists) |
cc259639 AW |
616 | */ |
617 | static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) | |
618 | { | |
619 | struct ovl_fs *ofs = dentry->d_sb->s_fs_info; | |
620 | struct dentry *root_dentry = dentry->d_sb->s_root; | |
621 | struct path path; | |
622 | int err; | |
623 | ||
4ebc5818 | 624 | ovl_path_real(root_dentry, &path); |
cc259639 AW |
625 | |
626 | err = vfs_statfs(&path, buf); | |
627 | if (!err) { | |
628 | buf->f_namelen = max(buf->f_namelen, ofs->lower_namelen); | |
629 | buf->f_type = OVERLAYFS_SUPER_MAGIC; | |
630 | } | |
631 | ||
632 | return err; | |
633 | } | |
634 | ||
f45827e8 EZ |
635 | /** |
636 | * ovl_show_options | |
637 | * | |
638 | * Prints the mount options for a given superblock. | |
639 | * Returns zero; does not fail. | |
640 | */ | |
641 | static int ovl_show_options(struct seq_file *m, struct dentry *dentry) | |
642 | { | |
643 | struct super_block *sb = dentry->d_sb; | |
644 | struct ovl_fs *ufs = sb->s_fs_info; | |
645 | ||
a068acf2 | 646 | seq_show_option(m, "lowerdir", ufs->config.lowerdir); |
53a08cb9 | 647 | if (ufs->config.upperdir) { |
a068acf2 KC |
648 | seq_show_option(m, "upperdir", ufs->config.upperdir); |
649 | seq_show_option(m, "workdir", ufs->config.workdir); | |
53a08cb9 | 650 | } |
8d3095f4 MS |
651 | if (ufs->config.default_permissions) |
652 | seq_puts(m, ",default_permissions"); | |
f45827e8 EZ |
653 | return 0; |
654 | } | |
655 | ||
3cdf6fe9 SL |
656 | static int ovl_remount(struct super_block *sb, int *flags, char *data) |
657 | { | |
658 | struct ovl_fs *ufs = sb->s_fs_info; | |
659 | ||
cc6f67bc | 660 | if (!(*flags & MS_RDONLY) && (!ufs->upper_mnt || !ufs->workdir)) |
3cdf6fe9 SL |
661 | return -EROFS; |
662 | ||
663 | return 0; | |
664 | } | |
665 | ||
e9be9d5e MS |
666 | static const struct super_operations ovl_super_operations = { |
667 | .put_super = ovl_put_super, | |
cc259639 | 668 | .statfs = ovl_statfs, |
f45827e8 | 669 | .show_options = ovl_show_options, |
3cdf6fe9 | 670 | .remount_fs = ovl_remount, |
e9be9d5e MS |
671 | }; |
672 | ||
673 | enum { | |
674 | OPT_LOWERDIR, | |
675 | OPT_UPPERDIR, | |
676 | OPT_WORKDIR, | |
8d3095f4 | 677 | OPT_DEFAULT_PERMISSIONS, |
e9be9d5e MS |
678 | OPT_ERR, |
679 | }; | |
680 | ||
681 | static const match_table_t ovl_tokens = { | |
682 | {OPT_LOWERDIR, "lowerdir=%s"}, | |
683 | {OPT_UPPERDIR, "upperdir=%s"}, | |
684 | {OPT_WORKDIR, "workdir=%s"}, | |
8d3095f4 | 685 | {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, |
e9be9d5e MS |
686 | {OPT_ERR, NULL} |
687 | }; | |
688 | ||
91c77947 MS |
689 | static char *ovl_next_opt(char **s) |
690 | { | |
691 | char *sbegin = *s; | |
692 | char *p; | |
693 | ||
694 | if (sbegin == NULL) | |
695 | return NULL; | |
696 | ||
697 | for (p = sbegin; *p; p++) { | |
698 | if (*p == '\\') { | |
699 | p++; | |
700 | if (!*p) | |
701 | break; | |
702 | } else if (*p == ',') { | |
703 | *p = '\0'; | |
704 | *s = p + 1; | |
705 | return sbegin; | |
706 | } | |
707 | } | |
708 | *s = NULL; | |
709 | return sbegin; | |
710 | } | |
711 | ||
e9be9d5e MS |
712 | static int ovl_parse_opt(char *opt, struct ovl_config *config) |
713 | { | |
714 | char *p; | |
715 | ||
91c77947 | 716 | while ((p = ovl_next_opt(&opt)) != NULL) { |
e9be9d5e MS |
717 | int token; |
718 | substring_t args[MAX_OPT_ARGS]; | |
719 | ||
720 | if (!*p) | |
721 | continue; | |
722 | ||
723 | token = match_token(p, ovl_tokens, args); | |
724 | switch (token) { | |
725 | case OPT_UPPERDIR: | |
726 | kfree(config->upperdir); | |
727 | config->upperdir = match_strdup(&args[0]); | |
728 | if (!config->upperdir) | |
729 | return -ENOMEM; | |
730 | break; | |
731 | ||
732 | case OPT_LOWERDIR: | |
733 | kfree(config->lowerdir); | |
734 | config->lowerdir = match_strdup(&args[0]); | |
735 | if (!config->lowerdir) | |
736 | return -ENOMEM; | |
737 | break; | |
738 | ||
739 | case OPT_WORKDIR: | |
740 | kfree(config->workdir); | |
741 | config->workdir = match_strdup(&args[0]); | |
742 | if (!config->workdir) | |
743 | return -ENOMEM; | |
744 | break; | |
745 | ||
8d3095f4 MS |
746 | case OPT_DEFAULT_PERMISSIONS: |
747 | config->default_permissions = true; | |
748 | break; | |
749 | ||
e9be9d5e | 750 | default: |
bead55ef | 751 | pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p); |
e9be9d5e MS |
752 | return -EINVAL; |
753 | } | |
754 | } | |
71cbad7e | 755 | |
756 | /* Workdir is useless in non-upper mount */ | |
757 | if (!config->upperdir && config->workdir) { | |
758 | pr_info("overlayfs: option \"workdir=%s\" is useless in a non-upper mount, ignore\n", | |
759 | config->workdir); | |
760 | kfree(config->workdir); | |
761 | config->workdir = NULL; | |
762 | } | |
763 | ||
e9be9d5e MS |
764 | return 0; |
765 | } | |
766 | ||
767 | #define OVL_WORKDIR_NAME "work" | |
768 | ||
769 | static struct dentry *ovl_workdir_create(struct vfsmount *mnt, | |
770 | struct dentry *dentry) | |
771 | { | |
772 | struct inode *dir = dentry->d_inode; | |
773 | struct dentry *work; | |
774 | int err; | |
775 | bool retried = false; | |
776 | ||
777 | err = mnt_want_write(mnt); | |
778 | if (err) | |
779 | return ERR_PTR(err); | |
780 | ||
5955102c | 781 | inode_lock_nested(dir, I_MUTEX_PARENT); |
e9be9d5e MS |
782 | retry: |
783 | work = lookup_one_len(OVL_WORKDIR_NAME, dentry, | |
784 | strlen(OVL_WORKDIR_NAME)); | |
785 | ||
786 | if (!IS_ERR(work)) { | |
787 | struct kstat stat = { | |
788 | .mode = S_IFDIR | 0, | |
789 | }; | |
790 | ||
791 | if (work->d_inode) { | |
792 | err = -EEXIST; | |
793 | if (retried) | |
794 | goto out_dput; | |
795 | ||
796 | retried = true; | |
797 | ovl_cleanup(dir, work); | |
798 | dput(work); | |
799 | goto retry; | |
800 | } | |
801 | ||
802 | err = ovl_create_real(dir, work, &stat, NULL, NULL, true); | |
803 | if (err) | |
804 | goto out_dput; | |
805 | } | |
806 | out_unlock: | |
5955102c | 807 | inode_unlock(dir); |
e9be9d5e MS |
808 | mnt_drop_write(mnt); |
809 | ||
810 | return work; | |
811 | ||
812 | out_dput: | |
813 | dput(work); | |
814 | work = ERR_PTR(err); | |
815 | goto out_unlock; | |
816 | } | |
817 | ||
91c77947 MS |
818 | static void ovl_unescape(char *s) |
819 | { | |
820 | char *d = s; | |
821 | ||
822 | for (;; s++, d++) { | |
823 | if (*s == '\\') | |
824 | s++; | |
825 | *d = *s; | |
826 | if (!*s) | |
827 | break; | |
828 | } | |
829 | } | |
830 | ||
ab508822 MS |
831 | static int ovl_mount_dir_noesc(const char *name, struct path *path) |
832 | { | |
a78d9f0d | 833 | int err = -EINVAL; |
ab508822 | 834 | |
a78d9f0d MS |
835 | if (!*name) { |
836 | pr_err("overlayfs: empty lowerdir\n"); | |
837 | goto out; | |
838 | } | |
ab508822 MS |
839 | err = kern_path(name, LOOKUP_FOLLOW, path); |
840 | if (err) { | |
841 | pr_err("overlayfs: failed to resolve '%s': %i\n", name, err); | |
842 | goto out; | |
843 | } | |
844 | err = -EINVAL; | |
7c03b5d4 | 845 | if (ovl_dentry_weird(path->dentry)) { |
ab508822 MS |
846 | pr_err("overlayfs: filesystem on '%s' not supported\n", name); |
847 | goto out_put; | |
848 | } | |
849 | if (!S_ISDIR(path->dentry->d_inode->i_mode)) { | |
850 | pr_err("overlayfs: '%s' not a directory\n", name); | |
851 | goto out_put; | |
852 | } | |
853 | return 0; | |
854 | ||
855 | out_put: | |
856 | path_put(path); | |
857 | out: | |
858 | return err; | |
859 | } | |
860 | ||
861 | static int ovl_mount_dir(const char *name, struct path *path) | |
862 | { | |
863 | int err = -ENOMEM; | |
864 | char *tmp = kstrdup(name, GFP_KERNEL); | |
865 | ||
866 | if (tmp) { | |
867 | ovl_unescape(tmp); | |
868 | err = ovl_mount_dir_noesc(tmp, path); | |
7c03b5d4 MS |
869 | |
870 | if (!err) | |
871 | if (ovl_dentry_remote(path->dentry)) { | |
872 | pr_err("overlayfs: filesystem on '%s' not supported as upperdir\n", | |
873 | tmp); | |
874 | path_put(path); | |
875 | err = -EINVAL; | |
876 | } | |
ab508822 MS |
877 | kfree(tmp); |
878 | } | |
879 | return err; | |
880 | } | |
881 | ||
882 | static int ovl_lower_dir(const char *name, struct path *path, long *namelen, | |
7c03b5d4 | 883 | int *stack_depth, bool *remote) |
ab508822 MS |
884 | { |
885 | int err; | |
886 | struct kstatfs statfs; | |
887 | ||
a78d9f0d | 888 | err = ovl_mount_dir_noesc(name, path); |
ab508822 MS |
889 | if (err) |
890 | goto out; | |
891 | ||
892 | err = vfs_statfs(path, &statfs); | |
893 | if (err) { | |
894 | pr_err("overlayfs: statfs failed on '%s'\n", name); | |
895 | goto out_put; | |
896 | } | |
897 | *namelen = max(*namelen, statfs.f_namelen); | |
898 | *stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth); | |
899 | ||
7c03b5d4 MS |
900 | if (ovl_dentry_remote(path->dentry)) |
901 | *remote = true; | |
902 | ||
ab508822 MS |
903 | return 0; |
904 | ||
905 | out_put: | |
906 | path_put(path); | |
907 | out: | |
908 | return err; | |
909 | } | |
910 | ||
e9be9d5e MS |
911 | /* Workdir should not be subdir of upperdir and vice versa */ |
912 | static bool ovl_workdir_ok(struct dentry *workdir, struct dentry *upperdir) | |
913 | { | |
914 | bool ok = false; | |
915 | ||
916 | if (workdir != upperdir) { | |
917 | ok = (lock_rename(workdir, upperdir) == NULL); | |
918 | unlock_rename(workdir, upperdir); | |
919 | } | |
920 | return ok; | |
921 | } | |
922 | ||
a78d9f0d MS |
923 | static unsigned int ovl_split_lowerdirs(char *str) |
924 | { | |
925 | unsigned int ctr = 1; | |
926 | char *s, *d; | |
927 | ||
928 | for (s = d = str;; s++, d++) { | |
929 | if (*s == '\\') { | |
930 | s++; | |
931 | } else if (*s == ':') { | |
932 | *d = '\0'; | |
933 | ctr++; | |
934 | continue; | |
935 | } | |
936 | *d = *s; | |
937 | if (!*s) | |
938 | break; | |
939 | } | |
940 | return ctr; | |
941 | } | |
942 | ||
e9be9d5e MS |
943 | static int ovl_fill_super(struct super_block *sb, void *data, int silent) |
944 | { | |
53a08cb9 MS |
945 | struct path upperpath = { NULL, NULL }; |
946 | struct path workpath = { NULL, NULL }; | |
e9be9d5e MS |
947 | struct dentry *root_dentry; |
948 | struct ovl_entry *oe; | |
949 | struct ovl_fs *ufs; | |
a78d9f0d MS |
950 | struct path *stack = NULL; |
951 | char *lowertmp; | |
952 | char *lower; | |
953 | unsigned int numlower; | |
954 | unsigned int stacklen = 0; | |
dd662667 | 955 | unsigned int i; |
7c03b5d4 | 956 | bool remote = false; |
e9be9d5e MS |
957 | int err; |
958 | ||
f45827e8 EZ |
959 | err = -ENOMEM; |
960 | ufs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); | |
961 | if (!ufs) | |
e9be9d5e MS |
962 | goto out; |
963 | ||
f45827e8 EZ |
964 | err = ovl_parse_opt((char *) data, &ufs->config); |
965 | if (err) | |
966 | goto out_free_config; | |
967 | ||
e9be9d5e | 968 | err = -EINVAL; |
53a08cb9 | 969 | if (!ufs->config.lowerdir) { |
07f2af7b KK |
970 | if (!silent) |
971 | pr_err("overlayfs: missing 'lowerdir'\n"); | |
e9be9d5e MS |
972 | goto out_free_config; |
973 | } | |
974 | ||
53a08cb9 | 975 | sb->s_stack_depth = 0; |
cf9a6784 | 976 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
53a08cb9 | 977 | if (ufs->config.upperdir) { |
53a08cb9 MS |
978 | if (!ufs->config.workdir) { |
979 | pr_err("overlayfs: missing 'workdir'\n"); | |
980 | goto out_free_config; | |
981 | } | |
e9be9d5e | 982 | |
53a08cb9 MS |
983 | err = ovl_mount_dir(ufs->config.upperdir, &upperpath); |
984 | if (err) | |
985 | goto out_free_config; | |
e9be9d5e | 986 | |
71cbad7e | 987 | /* Upper fs should not be r/o */ |
988 | if (upperpath.mnt->mnt_sb->s_flags & MS_RDONLY) { | |
989 | pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n"); | |
990 | err = -EINVAL; | |
991 | goto out_put_upperpath; | |
992 | } | |
993 | ||
53a08cb9 MS |
994 | err = ovl_mount_dir(ufs->config.workdir, &workpath); |
995 | if (err) | |
996 | goto out_put_upperpath; | |
997 | ||
2f83fd8c | 998 | err = -EINVAL; |
53a08cb9 MS |
999 | if (upperpath.mnt != workpath.mnt) { |
1000 | pr_err("overlayfs: workdir and upperdir must reside under the same mount\n"); | |
1001 | goto out_put_workpath; | |
1002 | } | |
1003 | if (!ovl_workdir_ok(workpath.dentry, upperpath.dentry)) { | |
1004 | pr_err("overlayfs: workdir and upperdir must be separate subtrees\n"); | |
1005 | goto out_put_workpath; | |
1006 | } | |
1007 | sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth; | |
cc259639 | 1008 | } |
a78d9f0d MS |
1009 | err = -ENOMEM; |
1010 | lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL); | |
1011 | if (!lowertmp) | |
ab508822 | 1012 | goto out_put_workpath; |
69c433ed | 1013 | |
a78d9f0d MS |
1014 | err = -EINVAL; |
1015 | stacklen = ovl_split_lowerdirs(lowertmp); | |
6be4506e | 1016 | if (stacklen > OVL_MAX_STACK) { |
1017 | pr_err("overlayfs: too many lower directries, limit is %d\n", | |
1018 | OVL_MAX_STACK); | |
a78d9f0d | 1019 | goto out_free_lowertmp; |
6be4506e | 1020 | } else if (!ufs->config.upperdir && stacklen == 1) { |
1021 | pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n"); | |
1022 | goto out_free_lowertmp; | |
1023 | } | |
a78d9f0d MS |
1024 | |
1025 | stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL); | |
1026 | if (!stack) | |
1027 | goto out_free_lowertmp; | |
1028 | ||
1029 | lower = lowertmp; | |
1030 | for (numlower = 0; numlower < stacklen; numlower++) { | |
1031 | err = ovl_lower_dir(lower, &stack[numlower], | |
7c03b5d4 MS |
1032 | &ufs->lower_namelen, &sb->s_stack_depth, |
1033 | &remote); | |
a78d9f0d MS |
1034 | if (err) |
1035 | goto out_put_lowerpath; | |
1036 | ||
1037 | lower = strchr(lower, '\0') + 1; | |
1038 | } | |
1039 | ||
69c433ed | 1040 | err = -EINVAL; |
ab508822 | 1041 | sb->s_stack_depth++; |
69c433ed MS |
1042 | if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { |
1043 | pr_err("overlayfs: maximum fs stacking depth exceeded\n"); | |
3b7a9a24 | 1044 | goto out_put_lowerpath; |
69c433ed MS |
1045 | } |
1046 | ||
53a08cb9 MS |
1047 | if (ufs->config.upperdir) { |
1048 | ufs->upper_mnt = clone_private_mount(&upperpath); | |
1049 | err = PTR_ERR(ufs->upper_mnt); | |
1050 | if (IS_ERR(ufs->upper_mnt)) { | |
1051 | pr_err("overlayfs: failed to clone upperpath\n"); | |
1052 | goto out_put_lowerpath; | |
1053 | } | |
3b7a9a24 | 1054 | |
53a08cb9 MS |
1055 | ufs->workdir = ovl_workdir_create(ufs->upper_mnt, workpath.dentry); |
1056 | err = PTR_ERR(ufs->workdir); | |
1057 | if (IS_ERR(ufs->workdir)) { | |
cc6f67bc MS |
1058 | pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n", |
1059 | ufs->config.workdir, OVL_WORKDIR_NAME, -err); | |
1060 | sb->s_flags |= MS_RDONLY; | |
1061 | ufs->workdir = NULL; | |
53a08cb9 | 1062 | } |
45aebeaf VG |
1063 | |
1064 | /* | |
1065 | * Upper should support d_type, else whiteouts are visible. | |
1066 | * Given workdir and upper are on same fs, we can do | |
1067 | * iterate_dir() on workdir. | |
1068 | */ | |
1069 | err = ovl_check_d_type_supported(&workpath); | |
1070 | if (err < 0) | |
1071 | goto out_put_workdir; | |
1072 | ||
1073 | if (!err) { | |
1074 | pr_err("overlayfs: upper fs needs to support d_type.\n"); | |
1075 | err = -EINVAL; | |
1076 | goto out_put_workdir; | |
1077 | } | |
e9be9d5e MS |
1078 | } |
1079 | ||
2f83fd8c | 1080 | err = -ENOMEM; |
a78d9f0d | 1081 | ufs->lower_mnt = kcalloc(numlower, sizeof(struct vfsmount *), GFP_KERNEL); |
dd662667 | 1082 | if (ufs->lower_mnt == NULL) |
3b7a9a24 | 1083 | goto out_put_workdir; |
a78d9f0d MS |
1084 | for (i = 0; i < numlower; i++) { |
1085 | struct vfsmount *mnt = clone_private_mount(&stack[i]); | |
dd662667 | 1086 | |
2f83fd8c | 1087 | err = PTR_ERR(mnt); |
a78d9f0d MS |
1088 | if (IS_ERR(mnt)) { |
1089 | pr_err("overlayfs: failed to clone lowerpath\n"); | |
1090 | goto out_put_lower_mnt; | |
1091 | } | |
1092 | /* | |
1093 | * Make lower_mnt R/O. That way fchmod/fchown on lower file | |
1094 | * will fail instead of modifying lower fs. | |
1095 | */ | |
1096 | mnt->mnt_flags |= MNT_READONLY; | |
dd662667 | 1097 | |
a78d9f0d MS |
1098 | ufs->lower_mnt[ufs->numlower] = mnt; |
1099 | ufs->numlower++; | |
1100 | } | |
e9be9d5e | 1101 | |
71cbad7e | 1102 | /* If the upper fs is nonexistent, we mark overlayfs r/o too */ |
1103 | if (!ufs->upper_mnt) | |
e9be9d5e MS |
1104 | sb->s_flags |= MS_RDONLY; |
1105 | ||
7c03b5d4 MS |
1106 | if (remote) |
1107 | sb->s_d_op = &ovl_reval_dentry_operations; | |
1108 | else | |
1109 | sb->s_d_op = &ovl_dentry_operations; | |
e9be9d5e MS |
1110 | |
1111 | err = -ENOMEM; | |
a78d9f0d | 1112 | oe = ovl_alloc_entry(numlower); |
3b7a9a24 MS |
1113 | if (!oe) |
1114 | goto out_put_lower_mnt; | |
e9be9d5e | 1115 | |
3b7a9a24 | 1116 | root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, oe)); |
e9be9d5e | 1117 | if (!root_dentry) |
3b7a9a24 | 1118 | goto out_free_oe; |
e9be9d5e MS |
1119 | |
1120 | mntput(upperpath.mnt); | |
a78d9f0d MS |
1121 | for (i = 0; i < numlower; i++) |
1122 | mntput(stack[i].mnt); | |
e9be9d5e | 1123 | path_put(&workpath); |
a78d9f0d | 1124 | kfree(lowertmp); |
e9be9d5e MS |
1125 | |
1126 | oe->__upperdentry = upperpath.dentry; | |
a78d9f0d MS |
1127 | for (i = 0; i < numlower; i++) { |
1128 | oe->lowerstack[i].dentry = stack[i].dentry; | |
1129 | oe->lowerstack[i].mnt = ufs->lower_mnt[i]; | |
1130 | } | |
0f95502a | 1131 | kfree(stack); |
e9be9d5e MS |
1132 | |
1133 | root_dentry->d_fsdata = oe; | |
1134 | ||
ed06e069 MS |
1135 | ovl_copyattr(ovl_dentry_real(root_dentry)->d_inode, |
1136 | root_dentry->d_inode); | |
1137 | ||
cc259639 | 1138 | sb->s_magic = OVERLAYFS_SUPER_MAGIC; |
e9be9d5e MS |
1139 | sb->s_op = &ovl_super_operations; |
1140 | sb->s_root = root_dentry; | |
1141 | sb->s_fs_info = ufs; | |
1142 | ||
1143 | return 0; | |
1144 | ||
3b7a9a24 MS |
1145 | out_free_oe: |
1146 | kfree(oe); | |
e9be9d5e | 1147 | out_put_lower_mnt: |
dd662667 MS |
1148 | for (i = 0; i < ufs->numlower; i++) |
1149 | mntput(ufs->lower_mnt[i]); | |
1150 | kfree(ufs->lower_mnt); | |
3b7a9a24 MS |
1151 | out_put_workdir: |
1152 | dput(ufs->workdir); | |
e9be9d5e | 1153 | mntput(ufs->upper_mnt); |
e9be9d5e | 1154 | out_put_lowerpath: |
a78d9f0d MS |
1155 | for (i = 0; i < numlower; i++) |
1156 | path_put(&stack[i]); | |
1157 | kfree(stack); | |
1158 | out_free_lowertmp: | |
1159 | kfree(lowertmp); | |
3b7a9a24 MS |
1160 | out_put_workpath: |
1161 | path_put(&workpath); | |
e9be9d5e MS |
1162 | out_put_upperpath: |
1163 | path_put(&upperpath); | |
e9be9d5e | 1164 | out_free_config: |
f45827e8 EZ |
1165 | kfree(ufs->config.lowerdir); |
1166 | kfree(ufs->config.upperdir); | |
1167 | kfree(ufs->config.workdir); | |
1168 | kfree(ufs); | |
e9be9d5e MS |
1169 | out: |
1170 | return err; | |
1171 | } | |
1172 | ||
1173 | static struct dentry *ovl_mount(struct file_system_type *fs_type, int flags, | |
1174 | const char *dev_name, void *raw_data) | |
1175 | { | |
1176 | return mount_nodev(fs_type, flags, raw_data, ovl_fill_super); | |
1177 | } | |
1178 | ||
1179 | static struct file_system_type ovl_fs_type = { | |
1180 | .owner = THIS_MODULE, | |
ef94b186 | 1181 | .name = "overlay", |
e9be9d5e MS |
1182 | .mount = ovl_mount, |
1183 | .kill_sb = kill_anon_super, | |
1184 | }; | |
ef94b186 | 1185 | MODULE_ALIAS_FS("overlay"); |
e9be9d5e MS |
1186 | |
1187 | static int __init ovl_init(void) | |
1188 | { | |
1189 | return register_filesystem(&ovl_fs_type); | |
1190 | } | |
1191 | ||
1192 | static void __exit ovl_exit(void) | |
1193 | { | |
1194 | unregister_filesystem(&ovl_fs_type); | |
1195 | } | |
1196 | ||
1197 | module_init(ovl_init); | |
1198 | module_exit(ovl_exit); |