This source file includes following definitions.
- xattr_iter_end
- xattr_iter_end_final
- init_inode_xattrs
- xattr_iter_fixup
- inline_xattr_iter_begin
- xattr_foreach
- xattr_entrymatch
- xattr_namematch
- xattr_checkbuffer
- xattr_copyvalue
- inline_getxattr
- shared_getxattr
- erofs_xattr_user_list
- erofs_xattr_trusted_list
- erofs_getxattr
- erofs_xattr_generic_get
- xattr_entrylist
- xattr_namelist
- xattr_skipvalue
- inline_listxattr
- shared_listxattr
- erofs_listxattr
- erofs_get_acl
1
2
3
4
5
6
7 #include <linux/security.h>
8 #include "xattr.h"
9
10 struct xattr_iter {
11 struct super_block *sb;
12 struct page *page;
13 void *kaddr;
14
15 erofs_blk_t blkaddr;
16 unsigned int ofs;
17 };
18
19 static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
20 {
21
22 if (!atomic)
23 kunmap(it->page);
24 else
25 kunmap_atomic(it->kaddr);
26
27 unlock_page(it->page);
28 put_page(it->page);
29 }
30
31 static inline void xattr_iter_end_final(struct xattr_iter *it)
32 {
33 if (!it->page)
34 return;
35
36 xattr_iter_end(it, true);
37 }
38
39 static int init_inode_xattrs(struct inode *inode)
40 {
41 struct erofs_inode *const vi = EROFS_I(inode);
42 struct xattr_iter it;
43 unsigned int i;
44 struct erofs_xattr_ibody_header *ih;
45 struct super_block *sb;
46 struct erofs_sb_info *sbi;
47 bool atomic_map;
48 int ret = 0;
49
50
51 if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags))
52 return 0;
53
54 if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE))
55 return -ERESTARTSYS;
56
57
58 if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags))
59 goto out_unlock;
60
61
62
63
64
65
66
67
68
69 if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) {
70 erofs_err(inode->i_sb,
71 "xattr_isize %d of nid %llu is not supported yet",
72 vi->xattr_isize, vi->nid);
73 ret = -EOPNOTSUPP;
74 goto out_unlock;
75 } else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) {
76 if (vi->xattr_isize) {
77 erofs_err(inode->i_sb,
78 "bogus xattr ibody @ nid %llu", vi->nid);
79 DBG_BUGON(1);
80 ret = -EFSCORRUPTED;
81 goto out_unlock;
82 }
83 ret = -ENOATTR;
84 goto out_unlock;
85 }
86
87 sb = inode->i_sb;
88 sbi = EROFS_SB(sb);
89 it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
90 it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
91
92 it.page = erofs_get_meta_page(sb, it.blkaddr);
93 if (IS_ERR(it.page)) {
94 ret = PTR_ERR(it.page);
95 goto out_unlock;
96 }
97
98
99 it.kaddr = kmap(it.page);
100 atomic_map = false;
101
102 ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
103
104 vi->xattr_shared_count = ih->h_shared_count;
105 vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
106 sizeof(uint), GFP_KERNEL);
107 if (!vi->xattr_shared_xattrs) {
108 xattr_iter_end(&it, atomic_map);
109 ret = -ENOMEM;
110 goto out_unlock;
111 }
112
113
114 it.ofs += sizeof(struct erofs_xattr_ibody_header);
115
116 for (i = 0; i < vi->xattr_shared_count; ++i) {
117 if (it.ofs >= EROFS_BLKSIZ) {
118
119 DBG_BUGON(it.ofs != EROFS_BLKSIZ);
120 xattr_iter_end(&it, atomic_map);
121
122 it.page = erofs_get_meta_page(sb, ++it.blkaddr);
123 if (IS_ERR(it.page)) {
124 kfree(vi->xattr_shared_xattrs);
125 vi->xattr_shared_xattrs = NULL;
126 ret = PTR_ERR(it.page);
127 goto out_unlock;
128 }
129
130 it.kaddr = kmap_atomic(it.page);
131 atomic_map = true;
132 it.ofs = 0;
133 }
134 vi->xattr_shared_xattrs[i] =
135 le32_to_cpu(*(__le32 *)(it.kaddr + it.ofs));
136 it.ofs += sizeof(__le32);
137 }
138 xattr_iter_end(&it, atomic_map);
139
140 set_bit(EROFS_I_EA_INITED_BIT, &vi->flags);
141
142 out_unlock:
143 clear_and_wake_up_bit(EROFS_I_BL_XATTR_BIT, &vi->flags);
144 return ret;
145 }
146
147
148
149
150
151
152
153
154 struct xattr_iter_handlers {
155 int (*entry)(struct xattr_iter *_it, struct erofs_xattr_entry *entry);
156 int (*name)(struct xattr_iter *_it, unsigned int processed, char *buf,
157 unsigned int len);
158 int (*alloc_buffer)(struct xattr_iter *_it, unsigned int value_sz);
159 void (*value)(struct xattr_iter *_it, unsigned int processed, char *buf,
160 unsigned int len);
161 };
162
163 static inline int xattr_iter_fixup(struct xattr_iter *it)
164 {
165 if (it->ofs < EROFS_BLKSIZ)
166 return 0;
167
168 xattr_iter_end(it, true);
169
170 it->blkaddr += erofs_blknr(it->ofs);
171
172 it->page = erofs_get_meta_page(it->sb, it->blkaddr);
173 if (IS_ERR(it->page)) {
174 int err = PTR_ERR(it->page);
175
176 it->page = NULL;
177 return err;
178 }
179
180 it->kaddr = kmap_atomic(it->page);
181 it->ofs = erofs_blkoff(it->ofs);
182 return 0;
183 }
184
185 static int inline_xattr_iter_begin(struct xattr_iter *it,
186 struct inode *inode)
187 {
188 struct erofs_inode *const vi = EROFS_I(inode);
189 struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb);
190 unsigned int xattr_header_sz, inline_xattr_ofs;
191
192 xattr_header_sz = inlinexattr_header_size(inode);
193 if (xattr_header_sz >= vi->xattr_isize) {
194 DBG_BUGON(xattr_header_sz > vi->xattr_isize);
195 return -ENOATTR;
196 }
197
198 inline_xattr_ofs = vi->inode_isize + xattr_header_sz;
199
200 it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs);
201 it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);
202
203 it->page = erofs_get_meta_page(inode->i_sb, it->blkaddr);
204 if (IS_ERR(it->page))
205 return PTR_ERR(it->page);
206
207 it->kaddr = kmap_atomic(it->page);
208 return vi->xattr_isize - xattr_header_sz;
209 }
210
211
212
213
214
215 static int xattr_foreach(struct xattr_iter *it,
216 const struct xattr_iter_handlers *op,
217 unsigned int *tlimit)
218 {
219 struct erofs_xattr_entry entry;
220 unsigned int value_sz, processed, slice;
221 int err;
222
223
224 err = xattr_iter_fixup(it);
225 if (err)
226 return err;
227
228
229
230
231
232
233 entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs);
234 if (tlimit) {
235 unsigned int entry_sz = erofs_xattr_entry_size(&entry);
236
237
238 if (*tlimit < entry_sz) {
239 DBG_BUGON(1);
240 return -EFSCORRUPTED;
241 }
242 *tlimit -= entry_sz;
243 }
244
245 it->ofs += sizeof(struct erofs_xattr_entry);
246 value_sz = le16_to_cpu(entry.e_value_size);
247
248
249 err = op->entry(it, &entry);
250 if (err) {
251 it->ofs += entry.e_name_len + value_sz;
252 goto out;
253 }
254
255
256 processed = 0;
257
258 while (processed < entry.e_name_len) {
259 if (it->ofs >= EROFS_BLKSIZ) {
260 DBG_BUGON(it->ofs > EROFS_BLKSIZ);
261
262 err = xattr_iter_fixup(it);
263 if (err)
264 goto out;
265 it->ofs = 0;
266 }
267
268 slice = min_t(unsigned int, PAGE_SIZE - it->ofs,
269 entry.e_name_len - processed);
270
271
272 err = op->name(it, processed, it->kaddr + it->ofs, slice);
273 if (err) {
274 it->ofs += entry.e_name_len - processed + value_sz;
275 goto out;
276 }
277
278 it->ofs += slice;
279 processed += slice;
280 }
281
282
283 processed = 0;
284
285 if (op->alloc_buffer) {
286 err = op->alloc_buffer(it, value_sz);
287 if (err) {
288 it->ofs += value_sz;
289 goto out;
290 }
291 }
292
293 while (processed < value_sz) {
294 if (it->ofs >= EROFS_BLKSIZ) {
295 DBG_BUGON(it->ofs > EROFS_BLKSIZ);
296
297 err = xattr_iter_fixup(it);
298 if (err)
299 goto out;
300 it->ofs = 0;
301 }
302
303 slice = min_t(unsigned int, PAGE_SIZE - it->ofs,
304 value_sz - processed);
305 op->value(it, processed, it->kaddr + it->ofs, slice);
306 it->ofs += slice;
307 processed += slice;
308 }
309
310 out:
311
312 it->ofs = EROFS_XATTR_ALIGN(it->ofs);
313 return err < 0 ? err : 0;
314 }
315
316 struct getxattr_iter {
317 struct xattr_iter it;
318
319 char *buffer;
320 int buffer_size, index;
321 struct qstr name;
322 };
323
324 static int xattr_entrymatch(struct xattr_iter *_it,
325 struct erofs_xattr_entry *entry)
326 {
327 struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
328
329 return (it->index != entry->e_name_index ||
330 it->name.len != entry->e_name_len) ? -ENOATTR : 0;
331 }
332
333 static int xattr_namematch(struct xattr_iter *_it,
334 unsigned int processed, char *buf, unsigned int len)
335 {
336 struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
337
338 return memcmp(buf, it->name.name + processed, len) ? -ENOATTR : 0;
339 }
340
341 static int xattr_checkbuffer(struct xattr_iter *_it,
342 unsigned int value_sz)
343 {
344 struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
345 int err = it->buffer_size < value_sz ? -ERANGE : 0;
346
347 it->buffer_size = value_sz;
348 return !it->buffer ? 1 : err;
349 }
350
351 static void xattr_copyvalue(struct xattr_iter *_it,
352 unsigned int processed,
353 char *buf, unsigned int len)
354 {
355 struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
356
357 memcpy(it->buffer + processed, buf, len);
358 }
359
360 static const struct xattr_iter_handlers find_xattr_handlers = {
361 .entry = xattr_entrymatch,
362 .name = xattr_namematch,
363 .alloc_buffer = xattr_checkbuffer,
364 .value = xattr_copyvalue
365 };
366
367 static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
368 {
369 int ret;
370 unsigned int remaining;
371
372 ret = inline_xattr_iter_begin(&it->it, inode);
373 if (ret < 0)
374 return ret;
375
376 remaining = ret;
377 while (remaining) {
378 ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining);
379 if (ret != -ENOATTR)
380 break;
381 }
382 xattr_iter_end_final(&it->it);
383
384 return ret ? ret : it->buffer_size;
385 }
386
387 static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
388 {
389 struct erofs_inode *const vi = EROFS_I(inode);
390 struct super_block *const sb = inode->i_sb;
391 struct erofs_sb_info *const sbi = EROFS_SB(sb);
392 unsigned int i;
393 int ret = -ENOATTR;
394
395 for (i = 0; i < vi->xattr_shared_count; ++i) {
396 erofs_blk_t blkaddr =
397 xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);
398
399 it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
400
401 if (!i || blkaddr != it->it.blkaddr) {
402 if (i)
403 xattr_iter_end(&it->it, true);
404
405 it->it.page = erofs_get_meta_page(sb, blkaddr);
406 if (IS_ERR(it->it.page))
407 return PTR_ERR(it->it.page);
408
409 it->it.kaddr = kmap_atomic(it->it.page);
410 it->it.blkaddr = blkaddr;
411 }
412
413 ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL);
414 if (ret != -ENOATTR)
415 break;
416 }
417 if (vi->xattr_shared_count)
418 xattr_iter_end_final(&it->it);
419
420 return ret ? ret : it->buffer_size;
421 }
422
423 static bool erofs_xattr_user_list(struct dentry *dentry)
424 {
425 return test_opt(EROFS_SB(dentry->d_sb), XATTR_USER);
426 }
427
428 static bool erofs_xattr_trusted_list(struct dentry *dentry)
429 {
430 return capable(CAP_SYS_ADMIN);
431 }
432
433 int erofs_getxattr(struct inode *inode, int index,
434 const char *name,
435 void *buffer, size_t buffer_size)
436 {
437 int ret;
438 struct getxattr_iter it;
439
440 if (!name)
441 return -EINVAL;
442
443 ret = init_inode_xattrs(inode);
444 if (ret)
445 return ret;
446
447 it.index = index;
448
449 it.name.len = strlen(name);
450 if (it.name.len > EROFS_NAME_LEN)
451 return -ERANGE;
452 it.name.name = name;
453
454 it.buffer = buffer;
455 it.buffer_size = buffer_size;
456
457 it.it.sb = inode->i_sb;
458 ret = inline_getxattr(inode, &it);
459 if (ret == -ENOATTR)
460 ret = shared_getxattr(inode, &it);
461 return ret;
462 }
463
464 static int erofs_xattr_generic_get(const struct xattr_handler *handler,
465 struct dentry *unused, struct inode *inode,
466 const char *name, void *buffer, size_t size)
467 {
468 struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
469
470 switch (handler->flags) {
471 case EROFS_XATTR_INDEX_USER:
472 if (!test_opt(sbi, XATTR_USER))
473 return -EOPNOTSUPP;
474 break;
475 case EROFS_XATTR_INDEX_TRUSTED:
476 if (!capable(CAP_SYS_ADMIN))
477 return -EPERM;
478 break;
479 case EROFS_XATTR_INDEX_SECURITY:
480 break;
481 default:
482 return -EINVAL;
483 }
484
485 return erofs_getxattr(inode, handler->flags, name, buffer, size);
486 }
487
488 const struct xattr_handler erofs_xattr_user_handler = {
489 .prefix = XATTR_USER_PREFIX,
490 .flags = EROFS_XATTR_INDEX_USER,
491 .list = erofs_xattr_user_list,
492 .get = erofs_xattr_generic_get,
493 };
494
495 const struct xattr_handler erofs_xattr_trusted_handler = {
496 .prefix = XATTR_TRUSTED_PREFIX,
497 .flags = EROFS_XATTR_INDEX_TRUSTED,
498 .list = erofs_xattr_trusted_list,
499 .get = erofs_xattr_generic_get,
500 };
501
502 #ifdef CONFIG_EROFS_FS_SECURITY
503 const struct xattr_handler __maybe_unused erofs_xattr_security_handler = {
504 .prefix = XATTR_SECURITY_PREFIX,
505 .flags = EROFS_XATTR_INDEX_SECURITY,
506 .get = erofs_xattr_generic_get,
507 };
508 #endif
509
510 const struct xattr_handler *erofs_xattr_handlers[] = {
511 &erofs_xattr_user_handler,
512 #ifdef CONFIG_EROFS_FS_POSIX_ACL
513 &posix_acl_access_xattr_handler,
514 &posix_acl_default_xattr_handler,
515 #endif
516 &erofs_xattr_trusted_handler,
517 #ifdef CONFIG_EROFS_FS_SECURITY
518 &erofs_xattr_security_handler,
519 #endif
520 NULL,
521 };
522
523 struct listxattr_iter {
524 struct xattr_iter it;
525
526 struct dentry *dentry;
527 char *buffer;
528 int buffer_size, buffer_ofs;
529 };
530
531 static int xattr_entrylist(struct xattr_iter *_it,
532 struct erofs_xattr_entry *entry)
533 {
534 struct listxattr_iter *it =
535 container_of(_it, struct listxattr_iter, it);
536 unsigned int prefix_len;
537 const char *prefix;
538
539 const struct xattr_handler *h =
540 erofs_xattr_handler(entry->e_name_index);
541
542 if (!h || (h->list && !h->list(it->dentry)))
543 return 1;
544
545 prefix = xattr_prefix(h);
546 prefix_len = strlen(prefix);
547
548 if (!it->buffer) {
549 it->buffer_ofs += prefix_len + entry->e_name_len + 1;
550 return 1;
551 }
552
553 if (it->buffer_ofs + prefix_len
554 + entry->e_name_len + 1 > it->buffer_size)
555 return -ERANGE;
556
557 memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len);
558 it->buffer_ofs += prefix_len;
559 return 0;
560 }
561
562 static int xattr_namelist(struct xattr_iter *_it,
563 unsigned int processed, char *buf, unsigned int len)
564 {
565 struct listxattr_iter *it =
566 container_of(_it, struct listxattr_iter, it);
567
568 memcpy(it->buffer + it->buffer_ofs, buf, len);
569 it->buffer_ofs += len;
570 return 0;
571 }
572
573 static int xattr_skipvalue(struct xattr_iter *_it,
574 unsigned int value_sz)
575 {
576 struct listxattr_iter *it =
577 container_of(_it, struct listxattr_iter, it);
578
579 it->buffer[it->buffer_ofs++] = '\0';
580 return 1;
581 }
582
583 static const struct xattr_iter_handlers list_xattr_handlers = {
584 .entry = xattr_entrylist,
585 .name = xattr_namelist,
586 .alloc_buffer = xattr_skipvalue,
587 .value = NULL
588 };
589
590 static int inline_listxattr(struct listxattr_iter *it)
591 {
592 int ret;
593 unsigned int remaining;
594
595 ret = inline_xattr_iter_begin(&it->it, d_inode(it->dentry));
596 if (ret < 0)
597 return ret;
598
599 remaining = ret;
600 while (remaining) {
601 ret = xattr_foreach(&it->it, &list_xattr_handlers, &remaining);
602 if (ret)
603 break;
604 }
605 xattr_iter_end_final(&it->it);
606 return ret ? ret : it->buffer_ofs;
607 }
608
609 static int shared_listxattr(struct listxattr_iter *it)
610 {
611 struct inode *const inode = d_inode(it->dentry);
612 struct erofs_inode *const vi = EROFS_I(inode);
613 struct super_block *const sb = inode->i_sb;
614 struct erofs_sb_info *const sbi = EROFS_SB(sb);
615 unsigned int i;
616 int ret = 0;
617
618 for (i = 0; i < vi->xattr_shared_count; ++i) {
619 erofs_blk_t blkaddr =
620 xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);
621
622 it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
623 if (!i || blkaddr != it->it.blkaddr) {
624 if (i)
625 xattr_iter_end(&it->it, true);
626
627 it->it.page = erofs_get_meta_page(sb, blkaddr);
628 if (IS_ERR(it->it.page))
629 return PTR_ERR(it->it.page);
630
631 it->it.kaddr = kmap_atomic(it->it.page);
632 it->it.blkaddr = blkaddr;
633 }
634
635 ret = xattr_foreach(&it->it, &list_xattr_handlers, NULL);
636 if (ret)
637 break;
638 }
639 if (vi->xattr_shared_count)
640 xattr_iter_end_final(&it->it);
641
642 return ret ? ret : it->buffer_ofs;
643 }
644
645 ssize_t erofs_listxattr(struct dentry *dentry,
646 char *buffer, size_t buffer_size)
647 {
648 int ret;
649 struct listxattr_iter it;
650
651 ret = init_inode_xattrs(d_inode(dentry));
652 if (ret == -ENOATTR)
653 return 0;
654 if (ret)
655 return ret;
656
657 it.dentry = dentry;
658 it.buffer = buffer;
659 it.buffer_size = buffer_size;
660 it.buffer_ofs = 0;
661
662 it.it.sb = dentry->d_sb;
663
664 ret = inline_listxattr(&it);
665 if (ret < 0 && ret != -ENOATTR)
666 return ret;
667 return shared_listxattr(&it);
668 }
669
670 #ifdef CONFIG_EROFS_FS_POSIX_ACL
671 struct posix_acl *erofs_get_acl(struct inode *inode, int type)
672 {
673 struct posix_acl *acl;
674 int prefix, rc;
675 char *value = NULL;
676
677 switch (type) {
678 case ACL_TYPE_ACCESS:
679 prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS;
680 break;
681 case ACL_TYPE_DEFAULT:
682 prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
683 break;
684 default:
685 return ERR_PTR(-EINVAL);
686 }
687
688 rc = erofs_getxattr(inode, prefix, "", NULL, 0);
689 if (rc > 0) {
690 value = kmalloc(rc, GFP_KERNEL);
691 if (!value)
692 return ERR_PTR(-ENOMEM);
693 rc = erofs_getxattr(inode, prefix, "", value, rc);
694 }
695
696 if (rc == -ENOATTR)
697 acl = NULL;
698 else if (rc < 0)
699 acl = ERR_PTR(rc);
700 else
701 acl = posix_acl_from_xattr(&init_user_ns, value, rc);
702 kfree(value);
703 return acl;
704 }
705 #endif
706