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/slab.h> | |
12 | #include <linux/namei.h> | |
13 | #include <linux/file.h> | |
14 | #include <linux/xattr.h> | |
15 | #include <linux/rbtree.h> | |
16 | #include <linux/security.h> | |
17 | #include <linux/cred.h> | |
b5efccbe | 18 | #include <linux/ratelimit.h> |
e9be9d5e MS |
19 | #include "overlayfs.h" |
20 | ||
21 | struct ovl_cache_entry { | |
e9be9d5e MS |
22 | unsigned int len; |
23 | unsigned int type; | |
b5efccbe | 24 | u64 real_ino; |
e9be9d5e | 25 | u64 ino; |
e9be9d5e MS |
26 | struct list_head l_node; |
27 | struct rb_node node; | |
cdb67279 | 28 | struct ovl_cache_entry *next_maybe_whiteout; |
c2096537 | 29 | bool is_whiteout; |
68bf8611 | 30 | char name[]; |
e9be9d5e MS |
31 | }; |
32 | ||
33 | struct ovl_dir_cache { | |
34 | long refcount; | |
35 | u64 version; | |
36 | struct list_head entries; | |
4edb83bb | 37 | struct rb_root root; |
e9be9d5e MS |
38 | }; |
39 | ||
40 | struct ovl_readdir_data { | |
41 | struct dir_context ctx; | |
3fe6e52f | 42 | struct dentry *dentry; |
56656e96 | 43 | bool is_lowest; |
4edb83bb | 44 | struct rb_root *root; |
e9be9d5e | 45 | struct list_head *list; |
db6ec212 | 46 | struct list_head middle; |
cdb67279 | 47 | struct ovl_cache_entry *first_maybe_whiteout; |
e9be9d5e MS |
48 | int count; |
49 | int err; | |
b5efccbe | 50 | bool is_upper; |
45aebeaf | 51 | bool d_type_supported; |
e9be9d5e MS |
52 | }; |
53 | ||
54 | struct ovl_dir_file { | |
55 | bool is_real; | |
56 | bool is_upper; | |
57 | struct ovl_dir_cache *cache; | |
4330397e | 58 | struct list_head *cursor; |
e9be9d5e MS |
59 | struct file *realfile; |
60 | struct file *upperfile; | |
61 | }; | |
62 | ||
63 | static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n) | |
64 | { | |
4edb83bb MS |
65 | return rb_entry(n, struct ovl_cache_entry, node); |
66 | } | |
67 | ||
68 | static bool ovl_cache_entry_find_link(const char *name, int len, | |
69 | struct rb_node ***link, | |
70 | struct rb_node **parent) | |
71 | { | |
72 | bool found = false; | |
73 | struct rb_node **newp = *link; | |
74 | ||
75 | while (!found && *newp) { | |
76 | int cmp; | |
77 | struct ovl_cache_entry *tmp; | |
78 | ||
79 | *parent = *newp; | |
80 | tmp = ovl_cache_entry_from_node(*newp); | |
81 | cmp = strncmp(name, tmp->name, len); | |
82 | if (cmp > 0) | |
83 | newp = &tmp->node.rb_right; | |
84 | else if (cmp < 0 || len < tmp->len) | |
85 | newp = &tmp->node.rb_left; | |
86 | else | |
87 | found = true; | |
88 | } | |
89 | *link = newp; | |
90 | ||
91 | return found; | |
e9be9d5e MS |
92 | } |
93 | ||
94 | static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root, | |
95 | const char *name, int len) | |
96 | { | |
97 | struct rb_node *node = root->rb_node; | |
98 | int cmp; | |
99 | ||
100 | while (node) { | |
101 | struct ovl_cache_entry *p = ovl_cache_entry_from_node(node); | |
102 | ||
103 | cmp = strncmp(name, p->name, len); | |
104 | if (cmp > 0) | |
105 | node = p->node.rb_right; | |
106 | else if (cmp < 0 || len < p->len) | |
107 | node = p->node.rb_left; | |
108 | else | |
109 | return p; | |
110 | } | |
111 | ||
112 | return NULL; | |
113 | } | |
114 | ||
b5efccbe AG |
115 | static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd, |
116 | struct ovl_cache_entry *p) | |
117 | { | |
118 | /* Don't care if not doing ovl_iter() */ | |
119 | if (!rdd->dentry) | |
120 | return false; | |
121 | ||
122 | /* Always recalc d_ino for parent */ | |
123 | if (strcmp(p->name, "..") == 0) | |
124 | return true; | |
125 | ||
126 | /* If this is lower, then native d_ino will do */ | |
127 | if (!rdd->is_upper) | |
128 | return false; | |
129 | ||
130 | /* | |
131 | * Recalc d_ino for '.' and for all entries if dir is impure (contains | |
132 | * copied up entries) | |
133 | */ | |
134 | if ((p->name[0] == '.' && p->len == 1) || | |
135 | ovl_test_flag(OVL_IMPURE, d_inode(rdd->dentry))) | |
136 | return true; | |
137 | ||
138 | return false; | |
139 | } | |
140 | ||
cdb67279 | 141 | static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, |
3e01cee3 | 142 | const char *name, int len, |
e9be9d5e MS |
143 | u64 ino, unsigned int d_type) |
144 | { | |
145 | struct ovl_cache_entry *p; | |
68bf8611 | 146 | size_t size = offsetof(struct ovl_cache_entry, name[len + 1]); |
e9be9d5e | 147 | |
68bf8611 | 148 | p = kmalloc(size, GFP_KERNEL); |
3e01cee3 MS |
149 | if (!p) |
150 | return NULL; | |
151 | ||
152 | memcpy(p->name, name, len); | |
153 | p->name[len] = '\0'; | |
154 | p->len = len; | |
155 | p->type = d_type; | |
b5efccbe | 156 | p->real_ino = ino; |
3e01cee3 | 157 | p->ino = ino; |
b5efccbe AG |
158 | /* Defer setting d_ino for upper entry to ovl_iterate() */ |
159 | if (ovl_calc_d_ino(rdd, p)) | |
160 | p->ino = 0; | |
3e01cee3 | 161 | p->is_whiteout = false; |
3e01cee3 MS |
162 | |
163 | if (d_type == DT_CHR) { | |
cdb67279 MS |
164 | p->next_maybe_whiteout = rdd->first_maybe_whiteout; |
165 | rdd->first_maybe_whiteout = p; | |
3e01cee3 | 166 | } |
e9be9d5e MS |
167 | return p; |
168 | } | |
169 | ||
170 | static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd, | |
171 | const char *name, int len, u64 ino, | |
172 | unsigned int d_type) | |
173 | { | |
4edb83bb | 174 | struct rb_node **newp = &rdd->root->rb_node; |
e9be9d5e MS |
175 | struct rb_node *parent = NULL; |
176 | struct ovl_cache_entry *p; | |
177 | ||
4edb83bb MS |
178 | if (ovl_cache_entry_find_link(name, len, &newp, &parent)) |
179 | return 0; | |
e9be9d5e | 180 | |
cdb67279 | 181 | p = ovl_cache_entry_new(rdd, name, len, ino, d_type); |
31e8ccea MS |
182 | if (p == NULL) { |
183 | rdd->err = -ENOMEM; | |
e9be9d5e | 184 | return -ENOMEM; |
31e8ccea | 185 | } |
e9be9d5e MS |
186 | |
187 | list_add_tail(&p->l_node, rdd->list); | |
188 | rb_link_node(&p->node, parent, newp); | |
4edb83bb | 189 | rb_insert_color(&p->node, rdd->root); |
e9be9d5e MS |
190 | |
191 | return 0; | |
192 | } | |
193 | ||
56656e96 MS |
194 | static int ovl_fill_lowest(struct ovl_readdir_data *rdd, |
195 | const char *name, int namelen, | |
196 | loff_t offset, u64 ino, unsigned int d_type) | |
e9be9d5e MS |
197 | { |
198 | struct ovl_cache_entry *p; | |
199 | ||
4edb83bb | 200 | p = ovl_cache_entry_find(rdd->root, name, namelen); |
e9be9d5e | 201 | if (p) { |
db6ec212 | 202 | list_move_tail(&p->l_node, &rdd->middle); |
e9be9d5e | 203 | } else { |
cdb67279 | 204 | p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type); |
e9be9d5e MS |
205 | if (p == NULL) |
206 | rdd->err = -ENOMEM; | |
207 | else | |
db6ec212 | 208 | list_add_tail(&p->l_node, &rdd->middle); |
e9be9d5e MS |
209 | } |
210 | ||
211 | return rdd->err; | |
212 | } | |
213 | ||
214 | void ovl_cache_free(struct list_head *list) | |
215 | { | |
216 | struct ovl_cache_entry *p; | |
217 | struct ovl_cache_entry *n; | |
218 | ||
219 | list_for_each_entry_safe(p, n, list, l_node) | |
220 | kfree(p); | |
221 | ||
222 | INIT_LIST_HEAD(list); | |
223 | } | |
224 | ||
4edb83bb MS |
225 | void ovl_dir_cache_free(struct inode *inode) |
226 | { | |
227 | struct ovl_dir_cache *cache = ovl_dir_cache(inode); | |
228 | ||
229 | if (cache) { | |
230 | ovl_cache_free(&cache->entries); | |
231 | kfree(cache); | |
232 | } | |
233 | } | |
234 | ||
e9be9d5e MS |
235 | static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry) |
236 | { | |
237 | struct ovl_dir_cache *cache = od->cache; | |
238 | ||
e9be9d5e MS |
239 | WARN_ON(cache->refcount <= 0); |
240 | cache->refcount--; | |
241 | if (!cache->refcount) { | |
4edb83bb MS |
242 | if (ovl_dir_cache(d_inode(dentry)) == cache) |
243 | ovl_set_dir_cache(d_inode(dentry), NULL); | |
e9be9d5e MS |
244 | |
245 | ovl_cache_free(&cache->entries); | |
246 | kfree(cache); | |
247 | } | |
248 | } | |
249 | ||
ac7576f4 MS |
250 | static int ovl_fill_merge(struct dir_context *ctx, const char *name, |
251 | int namelen, loff_t offset, u64 ino, | |
252 | unsigned int d_type) | |
e9be9d5e | 253 | { |
ac7576f4 MS |
254 | struct ovl_readdir_data *rdd = |
255 | container_of(ctx, struct ovl_readdir_data, ctx); | |
e9be9d5e MS |
256 | |
257 | rdd->count++; | |
56656e96 | 258 | if (!rdd->is_lowest) |
e9be9d5e MS |
259 | return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type); |
260 | else | |
56656e96 | 261 | return ovl_fill_lowest(rdd, name, namelen, offset, ino, d_type); |
e9be9d5e MS |
262 | } |
263 | ||
cdb67279 MS |
264 | static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd) |
265 | { | |
266 | int err; | |
267 | struct ovl_cache_entry *p; | |
268 | struct dentry *dentry; | |
269 | const struct cred *old_cred; | |
cdb67279 | 270 | |
3fe6e52f | 271 | old_cred = ovl_override_creds(rdd->dentry->d_sb); |
cdb67279 | 272 | |
00235411 | 273 | err = down_write_killable(&dir->d_inode->i_rwsem); |
cdb67279 MS |
274 | if (!err) { |
275 | while (rdd->first_maybe_whiteout) { | |
276 | p = rdd->first_maybe_whiteout; | |
277 | rdd->first_maybe_whiteout = p->next_maybe_whiteout; | |
278 | dentry = lookup_one_len(p->name, dir, p->len); | |
279 | if (!IS_ERR(dentry)) { | |
280 | p->is_whiteout = ovl_is_whiteout(dentry); | |
281 | dput(dentry); | |
282 | } | |
283 | } | |
5955102c | 284 | inode_unlock(dir->d_inode); |
cdb67279 MS |
285 | } |
286 | revert_creds(old_cred); | |
cdb67279 MS |
287 | |
288 | return err; | |
289 | } | |
290 | ||
e9be9d5e MS |
291 | static inline int ovl_dir_read(struct path *realpath, |
292 | struct ovl_readdir_data *rdd) | |
293 | { | |
294 | struct file *realfile; | |
295 | int err; | |
296 | ||
297 | realfile = ovl_path_open(realpath, O_RDONLY | O_DIRECTORY); | |
298 | if (IS_ERR(realfile)) | |
299 | return PTR_ERR(realfile); | |
300 | ||
cdb67279 | 301 | rdd->first_maybe_whiteout = NULL; |
e9be9d5e MS |
302 | rdd->ctx.pos = 0; |
303 | do { | |
304 | rdd->count = 0; | |
305 | rdd->err = 0; | |
306 | err = iterate_dir(realfile, &rdd->ctx); | |
307 | if (err >= 0) | |
308 | err = rdd->err; | |
309 | } while (!err && rdd->count); | |
cdb67279 | 310 | |
eea2fb48 | 311 | if (!err && rdd->first_maybe_whiteout && rdd->dentry) |
cdb67279 MS |
312 | err = ovl_check_whiteouts(realpath->dentry, rdd); |
313 | ||
e9be9d5e MS |
314 | fput(realfile); |
315 | ||
316 | return err; | |
317 | } | |
318 | ||
319 | static void ovl_dir_reset(struct file *file) | |
320 | { | |
321 | struct ovl_dir_file *od = file->private_data; | |
322 | struct ovl_dir_cache *cache = od->cache; | |
323 | struct dentry *dentry = file->f_path.dentry; | |
324 | enum ovl_path_type type = ovl_path_type(dentry); | |
325 | ||
326 | if (cache && ovl_dentry_version_get(dentry) != cache->version) { | |
327 | ovl_cache_put(od, dentry); | |
328 | od->cache = NULL; | |
4330397e | 329 | od->cursor = NULL; |
e9be9d5e | 330 | } |
1afaba1e MS |
331 | WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type)); |
332 | if (od->is_real && OVL_TYPE_MERGE(type)) | |
e9be9d5e MS |
333 | od->is_real = false; |
334 | } | |
335 | ||
4edb83bb MS |
336 | static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list, |
337 | struct rb_root *root) | |
e9be9d5e MS |
338 | { |
339 | int err; | |
9d7459d8 | 340 | struct path realpath; |
e9be9d5e MS |
341 | struct ovl_readdir_data rdd = { |
342 | .ctx.actor = ovl_fill_merge, | |
3fe6e52f | 343 | .dentry = dentry, |
e9be9d5e | 344 | .list = list, |
4edb83bb | 345 | .root = root, |
56656e96 | 346 | .is_lowest = false, |
e9be9d5e | 347 | }; |
9d7459d8 | 348 | int idx, next; |
e9be9d5e | 349 | |
9d7459d8 MS |
350 | for (idx = 0; idx != -1; idx = next) { |
351 | next = ovl_path_next(idx, dentry, &realpath); | |
b5efccbe | 352 | rdd.is_upper = ovl_dentry_upper(dentry) == realpath.dentry; |
c9f00fdb | 353 | |
9d7459d8 | 354 | if (next != -1) { |
9d7459d8 | 355 | err = ovl_dir_read(&realpath, &rdd); |
e9be9d5e | 356 | if (err) |
9d7459d8 MS |
357 | break; |
358 | } else { | |
359 | /* | |
360 | * Insert lowest layer entries before upper ones, this | |
361 | * allows offsets to be reasonably constant | |
362 | */ | |
363 | list_add(&rdd.middle, rdd.list); | |
56656e96 | 364 | rdd.is_lowest = true; |
9d7459d8 MS |
365 | err = ovl_dir_read(&realpath, &rdd); |
366 | list_del(&rdd.middle); | |
e9be9d5e MS |
367 | } |
368 | } | |
e9be9d5e | 369 | return err; |
e9be9d5e MS |
370 | } |
371 | ||
372 | static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos) | |
373 | { | |
4330397e | 374 | struct list_head *p; |
e9be9d5e MS |
375 | loff_t off = 0; |
376 | ||
4330397e | 377 | list_for_each(p, &od->cache->entries) { |
e9be9d5e MS |
378 | if (off >= pos) |
379 | break; | |
380 | off++; | |
381 | } | |
4330397e | 382 | /* Cursor is safe since the cache is stable */ |
383 | od->cursor = p; | |
e9be9d5e MS |
384 | } |
385 | ||
386 | static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) | |
387 | { | |
388 | int res; | |
e9be9d5e MS |
389 | struct ovl_dir_cache *cache; |
390 | ||
4edb83bb | 391 | cache = ovl_dir_cache(d_inode(dentry)); |
e9be9d5e | 392 | if (cache && ovl_dentry_version_get(dentry) == cache->version) { |
4edb83bb | 393 | WARN_ON(!cache->refcount); |
e9be9d5e MS |
394 | cache->refcount++; |
395 | return cache; | |
396 | } | |
4edb83bb | 397 | ovl_set_dir_cache(d_inode(dentry), NULL); |
e9be9d5e MS |
398 | |
399 | cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL); | |
400 | if (!cache) | |
401 | return ERR_PTR(-ENOMEM); | |
402 | ||
403 | cache->refcount = 1; | |
404 | INIT_LIST_HEAD(&cache->entries); | |
4edb83bb | 405 | cache->root = RB_ROOT; |
e9be9d5e | 406 | |
4edb83bb | 407 | res = ovl_dir_read_merged(dentry, &cache->entries, &cache->root); |
e9be9d5e MS |
408 | if (res) { |
409 | ovl_cache_free(&cache->entries); | |
410 | kfree(cache); | |
411 | return ERR_PTR(res); | |
412 | } | |
413 | ||
414 | cache->version = ovl_dentry_version_get(dentry); | |
4edb83bb | 415 | ovl_set_dir_cache(d_inode(dentry), cache); |
e9be9d5e MS |
416 | |
417 | return cache; | |
418 | } | |
419 | ||
b5efccbe AG |
420 | /* |
421 | * Set d_ino for upper entries. Non-upper entries should always report | |
422 | * the uppermost real inode ino and should not call this function. | |
423 | * | |
424 | * When not all layer are on same fs, report real ino also for upper. | |
425 | * | |
426 | * When all layers are on the same fs, and upper has a reference to | |
427 | * copy up origin, call vfs_getattr() on the overlay entry to make | |
428 | * sure that d_ino will be consistent with st_ino from stat(2). | |
429 | */ | |
430 | static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p) | |
431 | ||
432 | { | |
433 | struct dentry *dir = path->dentry; | |
434 | struct dentry *this = NULL; | |
435 | enum ovl_path_type type; | |
436 | u64 ino = p->real_ino; | |
437 | int err = 0; | |
438 | ||
439 | if (!ovl_same_sb(dir->d_sb)) | |
440 | goto out; | |
441 | ||
442 | if (p->name[0] == '.') { | |
443 | if (p->len == 1) { | |
444 | this = dget(dir); | |
445 | goto get; | |
446 | } | |
447 | if (p->len == 2 && p->name[1] == '.') { | |
448 | /* we shall not be moved */ | |
449 | this = dget(dir->d_parent); | |
450 | goto get; | |
451 | } | |
452 | } | |
453 | this = lookup_one_len(p->name, dir, p->len); | |
454 | if (IS_ERR_OR_NULL(this) || !this->d_inode) { | |
455 | if (IS_ERR(this)) { | |
456 | err = PTR_ERR(this); | |
457 | this = NULL; | |
458 | goto fail; | |
459 | } | |
460 | goto out; | |
461 | } | |
462 | ||
463 | get: | |
464 | type = ovl_path_type(this); | |
465 | if (OVL_TYPE_ORIGIN(type)) { | |
466 | struct kstat stat; | |
467 | struct path statpath = *path; | |
468 | ||
469 | statpath.dentry = this; | |
470 | err = vfs_getattr(&statpath, &stat, STATX_INO, 0); | |
471 | if (err) | |
472 | goto fail; | |
473 | ||
474 | WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev); | |
475 | ino = stat.ino; | |
476 | } | |
477 | ||
478 | out: | |
479 | p->ino = ino; | |
480 | dput(this); | |
481 | return err; | |
482 | ||
483 | fail: | |
484 | pr_warn_ratelimited("overlay: failed to look up (%s) for ino (%i)\n", | |
485 | p->name, err); | |
486 | goto out; | |
487 | } | |
488 | ||
4edb83bb MS |
489 | static int ovl_fill_plain(struct dir_context *ctx, const char *name, |
490 | int namelen, loff_t offset, u64 ino, | |
491 | unsigned int d_type) | |
492 | { | |
493 | struct ovl_cache_entry *p; | |
494 | struct ovl_readdir_data *rdd = | |
495 | container_of(ctx, struct ovl_readdir_data, ctx); | |
496 | ||
497 | rdd->count++; | |
498 | p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type); | |
499 | if (p == NULL) { | |
500 | rdd->err = -ENOMEM; | |
501 | return -ENOMEM; | |
502 | } | |
503 | list_add_tail(&p->l_node, rdd->list); | |
504 | ||
505 | return 0; | |
506 | } | |
507 | ||
508 | static int ovl_dir_read_impure(struct path *path, struct list_head *list, | |
509 | struct rb_root *root) | |
510 | { | |
511 | int err; | |
512 | struct path realpath; | |
513 | struct ovl_cache_entry *p, *n; | |
514 | struct ovl_readdir_data rdd = { | |
515 | .ctx.actor = ovl_fill_plain, | |
516 | .list = list, | |
517 | .root = root, | |
518 | }; | |
519 | ||
520 | INIT_LIST_HEAD(list); | |
521 | *root = RB_ROOT; | |
522 | ovl_path_upper(path->dentry, &realpath); | |
523 | ||
524 | err = ovl_dir_read(&realpath, &rdd); | |
525 | if (err) | |
526 | return err; | |
527 | ||
528 | list_for_each_entry_safe(p, n, list, l_node) { | |
529 | if (strcmp(p->name, ".") != 0 && | |
530 | strcmp(p->name, "..") != 0) { | |
531 | err = ovl_cache_update_ino(path, p); | |
532 | if (err) | |
533 | return err; | |
534 | } | |
535 | if (p->ino == p->real_ino) { | |
536 | list_del(&p->l_node); | |
537 | kfree(p); | |
538 | } else { | |
539 | struct rb_node **newp = &root->rb_node; | |
540 | struct rb_node *parent = NULL; | |
541 | ||
542 | if (WARN_ON(ovl_cache_entry_find_link(p->name, p->len, | |
543 | &newp, &parent))) | |
544 | return -EIO; | |
545 | ||
546 | rb_link_node(&p->node, parent, newp); | |
547 | rb_insert_color(&p->node, root); | |
548 | } | |
549 | } | |
550 | return 0; | |
551 | } | |
552 | ||
553 | static struct ovl_dir_cache *ovl_cache_get_impure(struct path *path) | |
554 | { | |
555 | int res; | |
556 | struct dentry *dentry = path->dentry; | |
557 | struct ovl_dir_cache *cache; | |
558 | ||
559 | cache = ovl_dir_cache(d_inode(dentry)); | |
560 | if (cache && ovl_dentry_version_get(dentry) == cache->version) | |
561 | return cache; | |
562 | ||
563 | /* Impure cache is not refcounted, free it here */ | |
564 | ovl_dir_cache_free(d_inode(dentry)); | |
565 | ovl_set_dir_cache(d_inode(dentry), NULL); | |
566 | ||
567 | cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL); | |
568 | if (!cache) | |
569 | return ERR_PTR(-ENOMEM); | |
570 | ||
571 | res = ovl_dir_read_impure(path, &cache->entries, &cache->root); | |
572 | if (res) { | |
573 | ovl_cache_free(&cache->entries); | |
574 | kfree(cache); | |
575 | return ERR_PTR(res); | |
576 | } | |
577 | if (list_empty(&cache->entries)) { | |
578 | /* Good oportunity to get rid of an unnecessary "impure" flag */ | |
579 | ovl_do_removexattr(ovl_dentry_upper(dentry), OVL_XATTR_IMPURE); | |
580 | ovl_clear_flag(OVL_IMPURE, d_inode(dentry)); | |
581 | kfree(cache); | |
582 | return NULL; | |
583 | } | |
584 | ||
585 | cache->version = ovl_dentry_version_get(dentry); | |
586 | ovl_set_dir_cache(d_inode(dentry), cache); | |
587 | ||
588 | return cache; | |
589 | } | |
590 | ||
591 | struct ovl_readdir_translate { | |
592 | struct dir_context *orig_ctx; | |
593 | struct ovl_dir_cache *cache; | |
594 | struct dir_context ctx; | |
595 | u64 parent_ino; | |
596 | }; | |
597 | ||
598 | static int ovl_fill_real(struct dir_context *ctx, const char *name, | |
599 | int namelen, loff_t offset, u64 ino, | |
600 | unsigned int d_type) | |
601 | { | |
602 | struct ovl_readdir_translate *rdt = | |
603 | container_of(ctx, struct ovl_readdir_translate, ctx); | |
604 | struct dir_context *orig_ctx = rdt->orig_ctx; | |
605 | ||
606 | if (rdt->parent_ino && strcmp(name, "..") == 0) | |
607 | ino = rdt->parent_ino; | |
608 | else if (rdt->cache) { | |
609 | struct ovl_cache_entry *p; | |
610 | ||
611 | p = ovl_cache_entry_find(&rdt->cache->root, name, namelen); | |
612 | if (p) | |
613 | ino = p->ino; | |
614 | } | |
615 | ||
616 | return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type); | |
617 | } | |
618 | ||
619 | static int ovl_iterate_real(struct file *file, struct dir_context *ctx) | |
620 | { | |
621 | int err; | |
622 | struct ovl_dir_file *od = file->private_data; | |
623 | struct dentry *dir = file->f_path.dentry; | |
624 | struct ovl_readdir_translate rdt = { | |
625 | .ctx.actor = ovl_fill_real, | |
626 | .orig_ctx = ctx, | |
627 | }; | |
628 | ||
629 | if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) { | |
630 | struct kstat stat; | |
631 | struct path statpath = file->f_path; | |
632 | ||
633 | statpath.dentry = dir->d_parent; | |
634 | err = vfs_getattr(&statpath, &stat, STATX_INO, 0); | |
635 | if (err) | |
636 | return err; | |
637 | ||
638 | WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev); | |
639 | rdt.parent_ino = stat.ino; | |
640 | } | |
641 | ||
642 | if (ovl_test_flag(OVL_IMPURE, d_inode(dir))) { | |
643 | rdt.cache = ovl_cache_get_impure(&file->f_path); | |
644 | if (IS_ERR(rdt.cache)) | |
645 | return PTR_ERR(rdt.cache); | |
646 | } | |
647 | ||
648 | return iterate_dir(od->realfile, &rdt.ctx); | |
649 | } | |
650 | ||
651 | ||
e9be9d5e MS |
652 | static int ovl_iterate(struct file *file, struct dir_context *ctx) |
653 | { | |
654 | struct ovl_dir_file *od = file->private_data; | |
655 | struct dentry *dentry = file->f_path.dentry; | |
4330397e | 656 | struct ovl_cache_entry *p; |
b5efccbe | 657 | int err; |
e9be9d5e MS |
658 | |
659 | if (!ctx->pos) | |
660 | ovl_dir_reset(file); | |
661 | ||
4edb83bb MS |
662 | if (od->is_real) { |
663 | /* | |
664 | * If parent is merge, then need to adjust d_ino for '..', if | |
665 | * dir is impure then need to adjust d_ino for copied up | |
666 | * entries. | |
667 | */ | |
668 | if (ovl_same_sb(dentry->d_sb) && | |
669 | (ovl_test_flag(OVL_IMPURE, d_inode(dentry)) || | |
670 | OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent)))) { | |
671 | return ovl_iterate_real(file, ctx); | |
672 | } | |
e9be9d5e | 673 | return iterate_dir(od->realfile, ctx); |
4edb83bb | 674 | } |
e9be9d5e MS |
675 | |
676 | if (!od->cache) { | |
677 | struct ovl_dir_cache *cache; | |
678 | ||
679 | cache = ovl_cache_get(dentry); | |
680 | if (IS_ERR(cache)) | |
681 | return PTR_ERR(cache); | |
682 | ||
683 | od->cache = cache; | |
684 | ovl_seek_cursor(od, ctx->pos); | |
685 | } | |
686 | ||
4330397e | 687 | while (od->cursor != &od->cache->entries) { |
688 | p = list_entry(od->cursor, struct ovl_cache_entry, l_node); | |
b5efccbe AG |
689 | if (!p->is_whiteout) { |
690 | if (!p->ino) { | |
691 | err = ovl_cache_update_ino(&file->f_path, p); | |
692 | if (err) | |
693 | return err; | |
694 | } | |
4330397e | 695 | if (!dir_emit(ctx, p->name, p->len, p->ino, p->type)) |
696 | break; | |
b5efccbe | 697 | } |
4330397e | 698 | od->cursor = p->l_node.next; |
699 | ctx->pos++; | |
e9be9d5e MS |
700 | } |
701 | return 0; | |
702 | } | |
703 | ||
704 | static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin) | |
705 | { | |
706 | loff_t res; | |
707 | struct ovl_dir_file *od = file->private_data; | |
708 | ||
5955102c | 709 | inode_lock(file_inode(file)); |
e9be9d5e MS |
710 | if (!file->f_pos) |
711 | ovl_dir_reset(file); | |
712 | ||
713 | if (od->is_real) { | |
714 | res = vfs_llseek(od->realfile, offset, origin); | |
715 | file->f_pos = od->realfile->f_pos; | |
716 | } else { | |
717 | res = -EINVAL; | |
718 | ||
719 | switch (origin) { | |
720 | case SEEK_CUR: | |
721 | offset += file->f_pos; | |
722 | break; | |
723 | case SEEK_SET: | |
724 | break; | |
725 | default: | |
726 | goto out_unlock; | |
727 | } | |
728 | if (offset < 0) | |
729 | goto out_unlock; | |
730 | ||
731 | if (offset != file->f_pos) { | |
732 | file->f_pos = offset; | |
733 | if (od->cache) | |
734 | ovl_seek_cursor(od, offset); | |
735 | } | |
736 | res = offset; | |
737 | } | |
738 | out_unlock: | |
5955102c | 739 | inode_unlock(file_inode(file)); |
e9be9d5e MS |
740 | |
741 | return res; | |
742 | } | |
743 | ||
744 | static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end, | |
745 | int datasync) | |
746 | { | |
747 | struct ovl_dir_file *od = file->private_data; | |
748 | struct dentry *dentry = file->f_path.dentry; | |
749 | struct file *realfile = od->realfile; | |
750 | ||
751 | /* | |
752 | * Need to check if we started out being a lower dir, but got copied up | |
753 | */ | |
1afaba1e | 754 | if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) { |
e9be9d5e MS |
755 | struct inode *inode = file_inode(file); |
756 | ||
506458ef | 757 | realfile = READ_ONCE(od->upperfile); |
e9be9d5e MS |
758 | if (!realfile) { |
759 | struct path upperpath; | |
760 | ||
761 | ovl_path_upper(dentry, &upperpath); | |
762 | realfile = ovl_path_open(&upperpath, O_RDONLY); | |
ff7a5fb0 | 763 | |
5955102c | 764 | inode_lock(inode); |
3d268c9b AV |
765 | if (!od->upperfile) { |
766 | if (IS_ERR(realfile)) { | |
5955102c | 767 | inode_unlock(inode); |
3d268c9b AV |
768 | return PTR_ERR(realfile); |
769 | } | |
ff7a5fb0 | 770 | smp_store_release(&od->upperfile, realfile); |
3d268c9b AV |
771 | } else { |
772 | /* somebody has beaten us to it */ | |
773 | if (!IS_ERR(realfile)) | |
774 | fput(realfile); | |
775 | realfile = od->upperfile; | |
e9be9d5e | 776 | } |
5955102c | 777 | inode_unlock(inode); |
e9be9d5e | 778 | } |
e9be9d5e MS |
779 | } |
780 | ||
781 | return vfs_fsync_range(realfile, start, end, datasync); | |
782 | } | |
783 | ||
784 | static int ovl_dir_release(struct inode *inode, struct file *file) | |
785 | { | |
786 | struct ovl_dir_file *od = file->private_data; | |
787 | ||
788 | if (od->cache) { | |
5955102c | 789 | inode_lock(inode); |
e9be9d5e | 790 | ovl_cache_put(od, file->f_path.dentry); |
5955102c | 791 | inode_unlock(inode); |
e9be9d5e MS |
792 | } |
793 | fput(od->realfile); | |
794 | if (od->upperfile) | |
795 | fput(od->upperfile); | |
796 | kfree(od); | |
797 | ||
798 | return 0; | |
799 | } | |
800 | ||
801 | static int ovl_dir_open(struct inode *inode, struct file *file) | |
802 | { | |
803 | struct path realpath; | |
804 | struct file *realfile; | |
805 | struct ovl_dir_file *od; | |
806 | enum ovl_path_type type; | |
807 | ||
808 | od = kzalloc(sizeof(struct ovl_dir_file), GFP_KERNEL); | |
809 | if (!od) | |
810 | return -ENOMEM; | |
811 | ||
812 | type = ovl_path_real(file->f_path.dentry, &realpath); | |
813 | realfile = ovl_path_open(&realpath, file->f_flags); | |
814 | if (IS_ERR(realfile)) { | |
815 | kfree(od); | |
816 | return PTR_ERR(realfile); | |
817 | } | |
e9be9d5e | 818 | od->realfile = realfile; |
1afaba1e MS |
819 | od->is_real = !OVL_TYPE_MERGE(type); |
820 | od->is_upper = OVL_TYPE_UPPER(type); | |
e9be9d5e MS |
821 | file->private_data = od; |
822 | ||
823 | return 0; | |
824 | } | |
825 | ||
826 | const struct file_operations ovl_dir_operations = { | |
827 | .read = generic_read_dir, | |
828 | .open = ovl_dir_open, | |
829 | .iterate = ovl_iterate, | |
830 | .llseek = ovl_dir_llseek, | |
831 | .fsync = ovl_dir_fsync, | |
832 | .release = ovl_dir_release, | |
833 | }; | |
834 | ||
835 | int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) | |
836 | { | |
837 | int err; | |
e9be9d5e | 838 | struct ovl_cache_entry *p; |
4edb83bb | 839 | struct rb_root root = RB_ROOT; |
e9be9d5e | 840 | |
4edb83bb | 841 | err = ovl_dir_read_merged(dentry, list, &root); |
e9be9d5e MS |
842 | if (err) |
843 | return err; | |
844 | ||
845 | err = 0; | |
846 | ||
847 | list_for_each_entry(p, list, l_node) { | |
848 | if (p->is_whiteout) | |
849 | continue; | |
850 | ||
851 | if (p->name[0] == '.') { | |
852 | if (p->len == 1) | |
853 | continue; | |
854 | if (p->len == 2 && p->name[1] == '.') | |
855 | continue; | |
856 | } | |
857 | err = -ENOTEMPTY; | |
858 | break; | |
859 | } | |
860 | ||
861 | return err; | |
862 | } | |
863 | ||
864 | void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) | |
865 | { | |
866 | struct ovl_cache_entry *p; | |
867 | ||
5955102c | 868 | inode_lock_nested(upper->d_inode, I_MUTEX_CHILD); |
e9be9d5e MS |
869 | list_for_each_entry(p, list, l_node) { |
870 | struct dentry *dentry; | |
871 | ||
872 | if (!p->is_whiteout) | |
873 | continue; | |
874 | ||
875 | dentry = lookup_one_len(p->name, upper, p->len); | |
876 | if (IS_ERR(dentry)) { | |
877 | pr_err("overlayfs: lookup '%s/%.*s' failed (%i)\n", | |
878 | upper->d_name.name, p->len, p->name, | |
879 | (int) PTR_ERR(dentry)); | |
880 | continue; | |
881 | } | |
84889d49 KK |
882 | if (dentry->d_inode) |
883 | ovl_cleanup(upper->d_inode, dentry); | |
e9be9d5e MS |
884 | dput(dentry); |
885 | } | |
5955102c | 886 | inode_unlock(upper->d_inode); |
e9be9d5e | 887 | } |
45aebeaf VG |
888 | |
889 | static int ovl_check_d_type(struct dir_context *ctx, const char *name, | |
890 | int namelen, loff_t offset, u64 ino, | |
891 | unsigned int d_type) | |
892 | { | |
893 | struct ovl_readdir_data *rdd = | |
894 | container_of(ctx, struct ovl_readdir_data, ctx); | |
895 | ||
896 | /* Even if d_type is not supported, DT_DIR is returned for . and .. */ | |
897 | if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen)) | |
898 | return 0; | |
899 | ||
900 | if (d_type != DT_UNKNOWN) | |
901 | rdd->d_type_supported = true; | |
902 | ||
903 | return 0; | |
904 | } | |
905 | ||
906 | /* | |
907 | * Returns 1 if d_type is supported, 0 not supported/unknown. Negative values | |
908 | * if error is encountered. | |
909 | */ | |
910 | int ovl_check_d_type_supported(struct path *realpath) | |
911 | { | |
912 | int err; | |
913 | struct ovl_readdir_data rdd = { | |
914 | .ctx.actor = ovl_check_d_type, | |
915 | .d_type_supported = false, | |
916 | }; | |
917 | ||
918 | err = ovl_dir_read(realpath, &rdd); | |
919 | if (err) | |
920 | return err; | |
921 | ||
922 | return rdd.d_type_supported; | |
923 | } | |
eea2fb48 MS |
924 | |
925 | static void ovl_workdir_cleanup_recurse(struct path *path, int level) | |
926 | { | |
927 | int err; | |
928 | struct inode *dir = path->dentry->d_inode; | |
929 | LIST_HEAD(list); | |
4edb83bb | 930 | struct rb_root root = RB_ROOT; |
eea2fb48 MS |
931 | struct ovl_cache_entry *p; |
932 | struct ovl_readdir_data rdd = { | |
933 | .ctx.actor = ovl_fill_merge, | |
934 | .dentry = NULL, | |
935 | .list = &list, | |
4edb83bb | 936 | .root = &root, |
eea2fb48 MS |
937 | .is_lowest = false, |
938 | }; | |
939 | ||
940 | err = ovl_dir_read(path, &rdd); | |
941 | if (err) | |
942 | goto out; | |
943 | ||
944 | inode_lock_nested(dir, I_MUTEX_PARENT); | |
945 | list_for_each_entry(p, &list, l_node) { | |
946 | struct dentry *dentry; | |
947 | ||
948 | if (p->name[0] == '.') { | |
949 | if (p->len == 1) | |
950 | continue; | |
951 | if (p->len == 2 && p->name[1] == '.') | |
952 | continue; | |
953 | } | |
954 | dentry = lookup_one_len(p->name, path->dentry, p->len); | |
955 | if (IS_ERR(dentry)) | |
956 | continue; | |
957 | if (dentry->d_inode) | |
958 | ovl_workdir_cleanup(dir, path->mnt, dentry, level); | |
959 | dput(dentry); | |
960 | } | |
961 | inode_unlock(dir); | |
962 | out: | |
963 | ovl_cache_free(&list); | |
964 | } | |
965 | ||
966 | void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, | |
967 | struct dentry *dentry, int level) | |
968 | { | |
969 | int err; | |
970 | ||
971 | if (!d_is_dir(dentry) || level > 1) { | |
972 | ovl_cleanup(dir, dentry); | |
973 | return; | |
974 | } | |
975 | ||
976 | err = ovl_do_rmdir(dir, dentry); | |
977 | if (err) { | |
978 | struct path path = { .mnt = mnt, .dentry = dentry }; | |
979 | ||
980 | inode_unlock(dir); | |
981 | ovl_workdir_cleanup_recurse(&path, level + 1); | |
982 | inode_lock_nested(dir, I_MUTEX_PARENT); | |
983 | ovl_cleanup(dir, dentry); | |
984 | } | |
985 | } | |
415543d5 AG |
986 | |
987 | int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, | |
988 | struct path *lowerstack, unsigned int numlower) | |
989 | { | |
990 | int err; | |
dc7ab677 | 991 | struct dentry *index = NULL; |
415543d5 AG |
992 | struct inode *dir = dentry->d_inode; |
993 | struct path path = { .mnt = mnt, .dentry = dentry }; | |
994 | LIST_HEAD(list); | |
4edb83bb | 995 | struct rb_root root = RB_ROOT; |
415543d5 AG |
996 | struct ovl_cache_entry *p; |
997 | struct ovl_readdir_data rdd = { | |
998 | .ctx.actor = ovl_fill_merge, | |
999 | .dentry = NULL, | |
1000 | .list = &list, | |
4edb83bb | 1001 | .root = &root, |
415543d5 AG |
1002 | .is_lowest = false, |
1003 | }; | |
1004 | ||
1005 | err = ovl_dir_read(&path, &rdd); | |
1006 | if (err) | |
1007 | goto out; | |
1008 | ||
1009 | inode_lock_nested(dir, I_MUTEX_PARENT); | |
1010 | list_for_each_entry(p, &list, l_node) { | |
415543d5 AG |
1011 | if (p->name[0] == '.') { |
1012 | if (p->len == 1) | |
1013 | continue; | |
1014 | if (p->len == 2 && p->name[1] == '.') | |
1015 | continue; | |
1016 | } | |
1017 | index = lookup_one_len(p->name, dentry, p->len); | |
1018 | if (IS_ERR(index)) { | |
1019 | err = PTR_ERR(index); | |
dc7ab677 | 1020 | index = NULL; |
415543d5 AG |
1021 | break; |
1022 | } | |
61b67471 AG |
1023 | err = ovl_verify_index(index, lowerstack, numlower); |
1024 | if (err) { | |
1025 | if (err == -EROFS) | |
1026 | break; | |
415543d5 AG |
1027 | err = ovl_cleanup(dir, index); |
1028 | if (err) | |
1029 | break; | |
1030 | } | |
1031 | dput(index); | |
dc7ab677 | 1032 | index = NULL; |
415543d5 | 1033 | } |
dc7ab677 | 1034 | dput(index); |
415543d5 AG |
1035 | inode_unlock(dir); |
1036 | out: | |
1037 | ovl_cache_free(&list); | |
1038 | if (err) | |
1039 | pr_err("overlayfs: failed index dir cleanup (%i)\n", err); | |
1040 | return err; | |
1041 | } |