xref: /openbmc/linux/fs/ntfs3/xattr.c (revision 12cecbf9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *
4  * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
5  *
6  */
7 
8 #include <linux/fs.h>
9 #include <linux/posix_acl.h>
10 #include <linux/posix_acl_xattr.h>
11 #include <linux/xattr.h>
12 
13 #include "debug.h"
14 #include "ntfs.h"
15 #include "ntfs_fs.h"
16 
17 // clang-format off
18 #define SYSTEM_DOS_ATTRIB    "system.dos_attrib"
19 #define SYSTEM_NTFS_ATTRIB   "system.ntfs_attrib"
20 #define SYSTEM_NTFS_SECURITY "system.ntfs_security"
21 // clang-format on
22 
23 static inline size_t unpacked_ea_size(const struct EA_FULL *ea)
24 {
25 	return ea->size ? le32_to_cpu(ea->size)
26 			: ALIGN(struct_size(ea, name,
27 					    1 + ea->name_len +
28 						    le16_to_cpu(ea->elength)),
29 				4);
30 }
31 
32 static inline size_t packed_ea_size(const struct EA_FULL *ea)
33 {
34 	return struct_size(ea, name,
35 			   1 + ea->name_len + le16_to_cpu(ea->elength)) -
36 	       offsetof(struct EA_FULL, flags);
37 }
38 
39 /*
40  * find_ea
41  *
42  * Assume there is at least one xattr in the list.
43  */
44 static inline bool find_ea(const struct EA_FULL *ea_all, u32 bytes,
45 			   const char *name, u8 name_len, u32 *off)
46 {
47 	*off = 0;
48 
49 	if (!ea_all || !bytes)
50 		return false;
51 
52 	for (;;) {
53 		const struct EA_FULL *ea = Add2Ptr(ea_all, *off);
54 		u32 next_off = *off + unpacked_ea_size(ea);
55 
56 		if (next_off > bytes)
57 			return false;
58 
59 		if (ea->name_len == name_len &&
60 		    !memcmp(ea->name, name, name_len))
61 			return true;
62 
63 		*off = next_off;
64 		if (next_off >= bytes)
65 			return false;
66 	}
67 }
68 
69 /*
70  * ntfs_read_ea - Read all extended attributes.
71  * @ea:		New allocated memory.
72  * @info:	Pointer into resident data.
73  */
74 static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
75 			size_t add_bytes, const struct EA_INFO **info)
76 {
77 	int err;
78 	struct ntfs_sb_info *sbi = ni->mi.sbi;
79 	struct ATTR_LIST_ENTRY *le = NULL;
80 	struct ATTRIB *attr_info, *attr_ea;
81 	void *ea_p;
82 	u32 size;
83 
84 	static_assert(le32_to_cpu(ATTR_EA_INFO) < le32_to_cpu(ATTR_EA));
85 
86 	*ea = NULL;
87 	*info = NULL;
88 
89 	attr_info =
90 		ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, NULL);
91 	attr_ea =
92 		ni_find_attr(ni, attr_info, &le, ATTR_EA, NULL, 0, NULL, NULL);
93 
94 	if (!attr_ea || !attr_info)
95 		return 0;
96 
97 	*info = resident_data_ex(attr_info, sizeof(struct EA_INFO));
98 	if (!*info)
99 		return -EINVAL;
100 
101 	/* Check Ea limit. */
102 	size = le32_to_cpu((*info)->size);
103 	if (size > sbi->ea_max_size)
104 		return -EFBIG;
105 
106 	if (attr_size(attr_ea) > sbi->ea_max_size)
107 		return -EFBIG;
108 
109 	/* Allocate memory for packed Ea. */
110 	ea_p = kmalloc(size + add_bytes, GFP_NOFS);
111 	if (!ea_p)
112 		return -ENOMEM;
113 
114 	if (!size) {
115 		/* EA info persists, but xattr is empty. Looks like EA problem. */
116 	} else if (attr_ea->non_res) {
117 		struct runs_tree run;
118 
119 		run_init(&run);
120 
121 		err = attr_load_runs(attr_ea, ni, &run, NULL);
122 		if (!err)
123 			err = ntfs_read_run_nb(sbi, &run, 0, ea_p, size, NULL);
124 		run_close(&run);
125 
126 		if (err)
127 			goto out;
128 	} else {
129 		void *p = resident_data_ex(attr_ea, size);
130 
131 		if (!p) {
132 			err = -EINVAL;
133 			goto out;
134 		}
135 		memcpy(ea_p, p, size);
136 	}
137 
138 	memset(Add2Ptr(ea_p, size), 0, add_bytes);
139 	*ea = ea_p;
140 	return 0;
141 
142 out:
143 	kfree(ea_p);
144 	*ea = NULL;
145 	return err;
146 }
147 
148 /*
149  * ntfs_list_ea
150  *
151  * Copy a list of xattrs names into the buffer
152  * provided, or compute the buffer size required.
153  *
154  * Return:
155  * * Number of bytes used / required on
156  * * -ERRNO - on failure
157  */
158 static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
159 			    size_t bytes_per_buffer)
160 {
161 	const struct EA_INFO *info;
162 	struct EA_FULL *ea_all = NULL;
163 	const struct EA_FULL *ea;
164 	u32 off, size;
165 	int err;
166 	size_t ret;
167 
168 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
169 	if (err)
170 		return err;
171 
172 	if (!info || !ea_all)
173 		return 0;
174 
175 	size = le32_to_cpu(info->size);
176 
177 	/* Enumerate all xattrs. */
178 	for (ret = 0, off = 0; off < size; off += unpacked_ea_size(ea)) {
179 		ea = Add2Ptr(ea_all, off);
180 
181 		if (buffer) {
182 			if (ret + ea->name_len + 1 > bytes_per_buffer) {
183 				err = -ERANGE;
184 				goto out;
185 			}
186 
187 			memcpy(buffer + ret, ea->name, ea->name_len);
188 			buffer[ret + ea->name_len] = 0;
189 		}
190 
191 		ret += ea->name_len + 1;
192 	}
193 
194 out:
195 	kfree(ea_all);
196 	return err ? err : ret;
197 }
198 
199 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
200 		       void *buffer, size_t size, size_t *required)
201 {
202 	struct ntfs_inode *ni = ntfs_i(inode);
203 	const struct EA_INFO *info;
204 	struct EA_FULL *ea_all = NULL;
205 	const struct EA_FULL *ea;
206 	u32 off, len;
207 	int err;
208 
209 	if (!(ni->ni_flags & NI_FLAG_EA))
210 		return -ENODATA;
211 
212 	if (!required)
213 		ni_lock(ni);
214 
215 	len = 0;
216 
217 	if (name_len > 255) {
218 		err = -ENAMETOOLONG;
219 		goto out;
220 	}
221 
222 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
223 	if (err)
224 		goto out;
225 
226 	if (!info)
227 		goto out;
228 
229 	/* Enumerate all xattrs. */
230 	if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, &off)) {
231 		err = -ENODATA;
232 		goto out;
233 	}
234 	ea = Add2Ptr(ea_all, off);
235 
236 	len = le16_to_cpu(ea->elength);
237 	if (!buffer) {
238 		err = 0;
239 		goto out;
240 	}
241 
242 	if (len > size) {
243 		err = -ERANGE;
244 		if (required)
245 			*required = len;
246 		goto out;
247 	}
248 
249 	memcpy(buffer, ea->name + ea->name_len + 1, len);
250 	err = 0;
251 
252 out:
253 	kfree(ea_all);
254 	if (!required)
255 		ni_unlock(ni);
256 
257 	return err ? err : len;
258 }
259 
260 static noinline int ntfs_set_ea(struct inode *inode, const char *name,
261 				size_t name_len, const void *value,
262 				size_t val_size, int flags, bool locked)
263 {
264 	struct ntfs_inode *ni = ntfs_i(inode);
265 	struct ntfs_sb_info *sbi = ni->mi.sbi;
266 	int err;
267 	struct EA_INFO ea_info;
268 	const struct EA_INFO *info;
269 	struct EA_FULL *new_ea;
270 	struct EA_FULL *ea_all = NULL;
271 	size_t add, new_pack;
272 	u32 off, size;
273 	__le16 size_pack;
274 	struct ATTRIB *attr;
275 	struct ATTR_LIST_ENTRY *le;
276 	struct mft_inode *mi;
277 	struct runs_tree ea_run;
278 	u64 new_sz;
279 	void *p;
280 
281 	if (!locked)
282 		ni_lock(ni);
283 
284 	run_init(&ea_run);
285 
286 	if (name_len > 255) {
287 		err = -ENAMETOOLONG;
288 		goto out;
289 	}
290 
291 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
292 
293 	err = ntfs_read_ea(ni, &ea_all, add, &info);
294 	if (err)
295 		goto out;
296 
297 	if (!info) {
298 		memset(&ea_info, 0, sizeof(ea_info));
299 		size = 0;
300 		size_pack = 0;
301 	} else {
302 		memcpy(&ea_info, info, sizeof(ea_info));
303 		size = le32_to_cpu(ea_info.size);
304 		size_pack = ea_info.size_pack;
305 	}
306 
307 	if (info && find_ea(ea_all, size, name, name_len, &off)) {
308 		struct EA_FULL *ea;
309 		size_t ea_sz;
310 
311 		if (flags & XATTR_CREATE) {
312 			err = -EEXIST;
313 			goto out;
314 		}
315 
316 		ea = Add2Ptr(ea_all, off);
317 
318 		/*
319 		 * Check simple case when we try to insert xattr with the same value
320 		 * e.g. ntfs_save_wsl_perm
321 		 */
322 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
323 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
324 			/* xattr already contains the required value. */
325 			goto out;
326 		}
327 
328 		/* Remove current xattr. */
329 		if (ea->flags & FILE_NEED_EA)
330 			le16_add_cpu(&ea_info.count, -1);
331 
332 		ea_sz = unpacked_ea_size(ea);
333 
334 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
335 
336 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
337 
338 		size -= ea_sz;
339 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
340 
341 		ea_info.size = cpu_to_le32(size);
342 
343 		if ((flags & XATTR_REPLACE) && !val_size) {
344 			/* Remove xattr. */
345 			goto update_ea;
346 		}
347 	} else {
348 		if (flags & XATTR_REPLACE) {
349 			err = -ENODATA;
350 			goto out;
351 		}
352 
353 		if (!ea_all) {
354 			ea_all = kzalloc(add, GFP_NOFS);
355 			if (!ea_all) {
356 				err = -ENOMEM;
357 				goto out;
358 			}
359 		}
360 	}
361 
362 	/* Append new xattr. */
363 	new_ea = Add2Ptr(ea_all, size);
364 	new_ea->size = cpu_to_le32(add);
365 	new_ea->flags = 0;
366 	new_ea->name_len = name_len;
367 	new_ea->elength = cpu_to_le16(val_size);
368 	memcpy(new_ea->name, name, name_len);
369 	new_ea->name[name_len] = 0;
370 	memcpy(new_ea->name + name_len + 1, value, val_size);
371 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
372 	ea_info.size_pack = cpu_to_le16(new_pack);
373 	/* New size of ATTR_EA. */
374 	size += add;
375 	ea_info.size = cpu_to_le32(size);
376 
377 	/*
378 	 * 1. Check ea_info.size_pack for overflow.
379 	 * 2. New attibute size must fit value from $AttrDef
380 	 */
381 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
382 		ntfs_inode_warn(
383 			inode,
384 			"The size of extended attributes must not exceed 64KiB");
385 		err = -EFBIG; // -EINVAL?
386 		goto out;
387 	}
388 
389 update_ea:
390 
391 	if (!info) {
392 		/* Create xattr. */
393 		if (!size) {
394 			err = 0;
395 			goto out;
396 		}
397 
398 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
399 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
400 					 NULL);
401 		if (err)
402 			goto out;
403 
404 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
405 					 NULL);
406 		if (err)
407 			goto out;
408 	}
409 
410 	new_sz = size;
411 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
412 			    false, NULL);
413 	if (err)
414 		goto out;
415 
416 	le = NULL;
417 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
418 	if (!attr) {
419 		err = -EINVAL;
420 		goto out;
421 	}
422 
423 	if (!size) {
424 		/* Delete xattr, ATTR_EA_INFO */
425 		ni_remove_attr_le(ni, attr, mi, le);
426 	} else {
427 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
428 		if (!p) {
429 			err = -EINVAL;
430 			goto out;
431 		}
432 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
433 		mi->dirty = true;
434 	}
435 
436 	le = NULL;
437 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
438 	if (!attr) {
439 		err = -EINVAL;
440 		goto out;
441 	}
442 
443 	if (!size) {
444 		/* Delete xattr, ATTR_EA */
445 		ni_remove_attr_le(ni, attr, mi, le);
446 	} else if (attr->non_res) {
447 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
448 		if (err)
449 			goto out;
450 	} else {
451 		p = resident_data_ex(attr, size);
452 		if (!p) {
453 			err = -EINVAL;
454 			goto out;
455 		}
456 		memcpy(p, ea_all, size);
457 		mi->dirty = true;
458 	}
459 
460 	/* Check if we delete the last xattr. */
461 	if (size)
462 		ni->ni_flags |= NI_FLAG_EA;
463 	else
464 		ni->ni_flags &= ~NI_FLAG_EA;
465 
466 	if (ea_info.size_pack != size_pack)
467 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
468 	mark_inode_dirty(&ni->vfs_inode);
469 
470 out:
471 	if (!locked)
472 		ni_unlock(ni);
473 
474 	run_close(&ea_run);
475 	kfree(ea_all);
476 
477 	return err;
478 }
479 
480 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
481 static struct posix_acl *ntfs_get_acl_ex(struct user_namespace *mnt_userns,
482 					 struct inode *inode, int type,
483 					 int locked)
484 {
485 	struct ntfs_inode *ni = ntfs_i(inode);
486 	const char *name;
487 	size_t name_len;
488 	struct posix_acl *acl;
489 	size_t req;
490 	int err;
491 	void *buf;
492 
493 	/* Allocate PATH_MAX bytes. */
494 	buf = __getname();
495 	if (!buf)
496 		return ERR_PTR(-ENOMEM);
497 
498 	/* Possible values of 'type' was already checked above. */
499 	if (type == ACL_TYPE_ACCESS) {
500 		name = XATTR_NAME_POSIX_ACL_ACCESS;
501 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
502 	} else {
503 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
504 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
505 	}
506 
507 	if (!locked)
508 		ni_lock(ni);
509 
510 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
511 
512 	if (!locked)
513 		ni_unlock(ni);
514 
515 	/* Translate extended attribute to acl. */
516 	if (err >= 0) {
517 		acl = posix_acl_from_xattr(mnt_userns, buf, err);
518 	} else if (err == -ENODATA) {
519 		acl = NULL;
520 	} else {
521 		acl = ERR_PTR(err);
522 	}
523 
524 	if (!IS_ERR(acl))
525 		set_cached_acl(inode, type, acl);
526 
527 	__putname(buf);
528 
529 	return acl;
530 }
531 
532 /*
533  * ntfs_get_acl - inode_operations::get_acl
534  */
535 struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu)
536 {
537 	if (rcu)
538 		return ERR_PTR(-ECHILD);
539 
540 	/* TODO: init_user_ns? */
541 	return ntfs_get_acl_ex(&init_user_ns, inode, type, 0);
542 }
543 
544 static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
545 				    struct inode *inode, struct posix_acl *acl,
546 				    int type, bool init_acl)
547 {
548 	const char *name;
549 	size_t size, name_len;
550 	void *value = NULL;
551 	int err = 0;
552 	int flags;
553 
554 	if (S_ISLNK(inode->i_mode))
555 		return -EOPNOTSUPP;
556 
557 	switch (type) {
558 	case ACL_TYPE_ACCESS:
559 		/* Do not change i_mode if we are in init_acl */
560 		if (acl && !init_acl) {
561 			umode_t mode;
562 
563 			err = posix_acl_update_mode(mnt_userns, inode, &mode,
564 						    &acl);
565 			if (err)
566 				goto out;
567 
568 			if (inode->i_mode != mode) {
569 				inode->i_mode = mode;
570 				mark_inode_dirty(inode);
571 			}
572 		}
573 		name = XATTR_NAME_POSIX_ACL_ACCESS;
574 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
575 		break;
576 
577 	case ACL_TYPE_DEFAULT:
578 		if (!S_ISDIR(inode->i_mode))
579 			return acl ? -EACCES : 0;
580 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
581 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
582 		break;
583 
584 	default:
585 		return -EINVAL;
586 	}
587 
588 	if (!acl) {
589 		/* Remove xattr if it can be presented via mode. */
590 		size = 0;
591 		value = NULL;
592 		flags = XATTR_REPLACE;
593 	} else {
594 		size = posix_acl_xattr_size(acl->a_count);
595 		value = kmalloc(size, GFP_NOFS);
596 		if (!value)
597 			return -ENOMEM;
598 		err = posix_acl_to_xattr(mnt_userns, acl, value, size);
599 		if (err < 0)
600 			goto out;
601 		flags = 0;
602 	}
603 
604 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0);
605 	if (err == -ENODATA && !size)
606 		err = 0; /* Removing non existed xattr. */
607 	if (!err)
608 		set_cached_acl(inode, type, acl);
609 
610 out:
611 	kfree(value);
612 
613 	return err;
614 }
615 
616 /*
617  * ntfs_set_acl - inode_operations::set_acl
618  */
619 int ntfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
620 		 struct posix_acl *acl, int type)
621 {
622 	return ntfs_set_acl_ex(mnt_userns, inode, acl, type, false);
623 }
624 
625 static int ntfs_xattr_get_acl(struct user_namespace *mnt_userns,
626 			      struct inode *inode, int type, void *buffer,
627 			      size_t size)
628 {
629 	struct posix_acl *acl;
630 	int err;
631 
632 	if (!(inode->i_sb->s_flags & SB_POSIXACL)) {
633 		ntfs_inode_warn(inode, "add mount option \"acl\" to use acl");
634 		return -EOPNOTSUPP;
635 	}
636 
637 	acl = ntfs_get_acl(inode, type, false);
638 	if (IS_ERR(acl))
639 		return PTR_ERR(acl);
640 
641 	if (!acl)
642 		return -ENODATA;
643 
644 	err = posix_acl_to_xattr(mnt_userns, acl, buffer, size);
645 	posix_acl_release(acl);
646 
647 	return err;
648 }
649 
650 static int ntfs_xattr_set_acl(struct user_namespace *mnt_userns,
651 			      struct inode *inode, int type, const void *value,
652 			      size_t size)
653 {
654 	struct posix_acl *acl;
655 	int err;
656 
657 	if (!(inode->i_sb->s_flags & SB_POSIXACL)) {
658 		ntfs_inode_warn(inode, "add mount option \"acl\" to use acl");
659 		return -EOPNOTSUPP;
660 	}
661 
662 	if (!inode_owner_or_capable(mnt_userns, inode))
663 		return -EPERM;
664 
665 	if (!value) {
666 		acl = NULL;
667 	} else {
668 		acl = posix_acl_from_xattr(mnt_userns, value, size);
669 		if (IS_ERR(acl))
670 			return PTR_ERR(acl);
671 
672 		if (acl) {
673 			err = posix_acl_valid(mnt_userns, acl);
674 			if (err)
675 				goto release_and_out;
676 		}
677 	}
678 
679 	err = ntfs_set_acl(mnt_userns, inode, acl, type);
680 
681 release_and_out:
682 	posix_acl_release(acl);
683 	return err;
684 }
685 
686 /*
687  * ntfs_init_acl - Initialize the ACLs of a new inode.
688  *
689  * Called from ntfs_create_inode().
690  */
691 int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
692 		  struct inode *dir)
693 {
694 	struct posix_acl *default_acl, *acl;
695 	int err;
696 
697 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
698 	if (err)
699 		return err;
700 
701 	if (default_acl) {
702 		err = ntfs_set_acl_ex(mnt_userns, inode, default_acl,
703 				      ACL_TYPE_DEFAULT, true);
704 		posix_acl_release(default_acl);
705 	} else {
706 		inode->i_default_acl = NULL;
707 	}
708 
709 	if (!acl)
710 		inode->i_acl = NULL;
711 	else {
712 		if (!err)
713 			err = ntfs_set_acl_ex(mnt_userns, inode, acl,
714 					      ACL_TYPE_ACCESS, true);
715 		posix_acl_release(acl);
716 	}
717 
718 	return err;
719 }
720 #endif
721 
722 /*
723  * ntfs_acl_chmod - Helper for ntfs3_setattr().
724  */
725 int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct inode *inode)
726 {
727 	struct super_block *sb = inode->i_sb;
728 
729 	if (!(sb->s_flags & SB_POSIXACL))
730 		return 0;
731 
732 	if (S_ISLNK(inode->i_mode))
733 		return -EOPNOTSUPP;
734 
735 	return posix_acl_chmod(mnt_userns, inode, inode->i_mode);
736 }
737 
738 /*
739  * ntfs_permission - inode_operations::permission
740  */
741 int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
742 		    int mask)
743 {
744 	if (ntfs_sb(inode->i_sb)->options->noacsrules) {
745 		/* "No access rules" mode - Allow all changes. */
746 		return 0;
747 	}
748 
749 	return generic_permission(mnt_userns, inode, mask);
750 }
751 
752 /*
753  * ntfs_listxattr - inode_operations::listxattr
754  */
755 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
756 {
757 	struct inode *inode = d_inode(dentry);
758 	struct ntfs_inode *ni = ntfs_i(inode);
759 	ssize_t ret;
760 
761 	if (!(ni->ni_flags & NI_FLAG_EA)) {
762 		/* no xattr in file */
763 		return 0;
764 	}
765 
766 	ni_lock(ni);
767 
768 	ret = ntfs_list_ea(ni, buffer, size);
769 
770 	ni_unlock(ni);
771 
772 	return ret;
773 }
774 
775 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
776 			 struct inode *inode, const char *name, void *buffer,
777 			 size_t size)
778 {
779 	int err;
780 	struct ntfs_inode *ni = ntfs_i(inode);
781 	size_t name_len = strlen(name);
782 
783 	/* Dispatch request. */
784 	if (name_len == sizeof(SYSTEM_DOS_ATTRIB) - 1 &&
785 	    !memcmp(name, SYSTEM_DOS_ATTRIB, sizeof(SYSTEM_DOS_ATTRIB))) {
786 		/* system.dos_attrib */
787 		if (!buffer) {
788 			err = sizeof(u8);
789 		} else if (size < sizeof(u8)) {
790 			err = -ENODATA;
791 		} else {
792 			err = sizeof(u8);
793 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
794 		}
795 		goto out;
796 	}
797 
798 	if (name_len == sizeof(SYSTEM_NTFS_ATTRIB) - 1 &&
799 	    !memcmp(name, SYSTEM_NTFS_ATTRIB, sizeof(SYSTEM_NTFS_ATTRIB))) {
800 		/* system.ntfs_attrib */
801 		if (!buffer) {
802 			err = sizeof(u32);
803 		} else if (size < sizeof(u32)) {
804 			err = -ENODATA;
805 		} else {
806 			err = sizeof(u32);
807 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
808 		}
809 		goto out;
810 	}
811 
812 	if (name_len == sizeof(SYSTEM_NTFS_SECURITY) - 1 &&
813 	    !memcmp(name, SYSTEM_NTFS_SECURITY, sizeof(SYSTEM_NTFS_SECURITY))) {
814 		/* system.ntfs_security*/
815 		struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
816 		size_t sd_size = 0;
817 
818 		if (!is_ntfs3(ni->mi.sbi)) {
819 			/* We should get nt4 security. */
820 			err = -EINVAL;
821 			goto out;
822 		} else if (le32_to_cpu(ni->std_security_id) <
823 			   SECURITY_ID_FIRST) {
824 			err = -ENOENT;
825 			goto out;
826 		}
827 
828 		err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
829 					      &sd, &sd_size);
830 		if (err)
831 			goto out;
832 
833 		if (!is_sd_valid(sd, sd_size)) {
834 			ntfs_inode_warn(
835 				inode,
836 				"looks like you get incorrect security descriptor id=%u",
837 				ni->std_security_id);
838 		}
839 
840 		if (!buffer) {
841 			err = sd_size;
842 		} else if (size < sd_size) {
843 			err = -ENODATA;
844 		} else {
845 			err = sd_size;
846 			memcpy(buffer, sd, sd_size);
847 		}
848 		kfree(sd);
849 		goto out;
850 	}
851 
852 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
853 	if ((name_len == sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1 &&
854 	     !memcmp(name, XATTR_NAME_POSIX_ACL_ACCESS,
855 		     sizeof(XATTR_NAME_POSIX_ACL_ACCESS))) ||
856 	    (name_len == sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1 &&
857 	     !memcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT,
858 		     sizeof(XATTR_NAME_POSIX_ACL_DEFAULT)))) {
859 		/* TODO: init_user_ns? */
860 		err = ntfs_xattr_get_acl(
861 			&init_user_ns, inode,
862 			name_len == sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1
863 				? ACL_TYPE_ACCESS
864 				: ACL_TYPE_DEFAULT,
865 			buffer, size);
866 		goto out;
867 	}
868 #endif
869 	/* Deal with NTFS extended attribute. */
870 	err = ntfs_get_ea(inode, name, name_len, buffer, size, NULL);
871 
872 out:
873 	return err;
874 }
875 
876 /*
877  * ntfs_setxattr - inode_operations::setxattr
878  */
879 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
880 				  struct user_namespace *mnt_userns,
881 				  struct dentry *de, struct inode *inode,
882 				  const char *name, const void *value,
883 				  size_t size, int flags)
884 {
885 	int err = -EINVAL;
886 	struct ntfs_inode *ni = ntfs_i(inode);
887 	size_t name_len = strlen(name);
888 	enum FILE_ATTRIBUTE new_fa;
889 
890 	/* Dispatch request. */
891 	if (name_len == sizeof(SYSTEM_DOS_ATTRIB) - 1 &&
892 	    !memcmp(name, SYSTEM_DOS_ATTRIB, sizeof(SYSTEM_DOS_ATTRIB))) {
893 		if (sizeof(u8) != size)
894 			goto out;
895 		new_fa = cpu_to_le32(*(u8 *)value);
896 		goto set_new_fa;
897 	}
898 
899 	if (name_len == sizeof(SYSTEM_NTFS_ATTRIB) - 1 &&
900 	    !memcmp(name, SYSTEM_NTFS_ATTRIB, sizeof(SYSTEM_NTFS_ATTRIB))) {
901 		if (size != sizeof(u32))
902 			goto out;
903 		new_fa = cpu_to_le32(*(u32 *)value);
904 
905 		if (S_ISREG(inode->i_mode)) {
906 			/* Process compressed/sparsed in special way. */
907 			ni_lock(ni);
908 			err = ni_new_attr_flags(ni, new_fa);
909 			ni_unlock(ni);
910 			if (err)
911 				goto out;
912 		}
913 set_new_fa:
914 		/*
915 		 * Thanks Mark Harmstone:
916 		 * Keep directory bit consistency.
917 		 */
918 		if (S_ISDIR(inode->i_mode))
919 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
920 		else
921 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
922 
923 		if (ni->std_fa != new_fa) {
924 			ni->std_fa = new_fa;
925 			if (new_fa & FILE_ATTRIBUTE_READONLY)
926 				inode->i_mode &= ~0222;
927 			else
928 				inode->i_mode |= 0222;
929 			/* Std attribute always in primary record. */
930 			ni->mi.dirty = true;
931 			mark_inode_dirty(inode);
932 		}
933 		err = 0;
934 
935 		goto out;
936 	}
937 
938 	if (name_len == sizeof(SYSTEM_NTFS_SECURITY) - 1 &&
939 	    !memcmp(name, SYSTEM_NTFS_SECURITY, sizeof(SYSTEM_NTFS_SECURITY))) {
940 		/* system.ntfs_security*/
941 		__le32 security_id;
942 		bool inserted;
943 		struct ATTR_STD_INFO5 *std;
944 
945 		if (!is_ntfs3(ni->mi.sbi)) {
946 			/*
947 			 * We should replace ATTR_SECURE.
948 			 * Skip this way cause it is nt4 feature.
949 			 */
950 			err = -EINVAL;
951 			goto out;
952 		}
953 
954 		if (!is_sd_valid(value, size)) {
955 			err = -EINVAL;
956 			ntfs_inode_warn(
957 				inode,
958 				"you try to set invalid security descriptor");
959 			goto out;
960 		}
961 
962 		err = ntfs_insert_security(ni->mi.sbi, value, size,
963 					   &security_id, &inserted);
964 		if (err)
965 			goto out;
966 
967 		ni_lock(ni);
968 		std = ni_std5(ni);
969 		if (!std) {
970 			err = -EINVAL;
971 		} else if (std->security_id != security_id) {
972 			std->security_id = ni->std_security_id = security_id;
973 			/* Std attribute always in primary record. */
974 			ni->mi.dirty = true;
975 			mark_inode_dirty(&ni->vfs_inode);
976 		}
977 		ni_unlock(ni);
978 		goto out;
979 	}
980 
981 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
982 	if ((name_len == sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1 &&
983 	     !memcmp(name, XATTR_NAME_POSIX_ACL_ACCESS,
984 		     sizeof(XATTR_NAME_POSIX_ACL_ACCESS))) ||
985 	    (name_len == sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1 &&
986 	     !memcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT,
987 		     sizeof(XATTR_NAME_POSIX_ACL_DEFAULT)))) {
988 		err = ntfs_xattr_set_acl(
989 			mnt_userns, inode,
990 			name_len == sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1
991 				? ACL_TYPE_ACCESS
992 				: ACL_TYPE_DEFAULT,
993 			value, size);
994 		goto out;
995 	}
996 #endif
997 	/* Deal with NTFS extended attribute. */
998 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0);
999 
1000 out:
1001 	inode->i_ctime = current_time(inode);
1002 	mark_inode_dirty(inode);
1003 
1004 	return err;
1005 }
1006 
1007 /*
1008  * ntfs_save_wsl_perm
1009  *
1010  * save uid/gid/mode in xattr
1011  */
1012 int ntfs_save_wsl_perm(struct inode *inode)
1013 {
1014 	int err;
1015 	__le32 value;
1016 	struct ntfs_inode *ni = ntfs_i(inode);
1017 
1018 	ni_lock(ni);
1019 	value = cpu_to_le32(i_uid_read(inode));
1020 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
1021 			  sizeof(value), 0, true); /* true == already locked. */
1022 	if (err)
1023 		goto out;
1024 
1025 	value = cpu_to_le32(i_gid_read(inode));
1026 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
1027 			  sizeof(value), 0, true);
1028 	if (err)
1029 		goto out;
1030 
1031 	value = cpu_to_le32(inode->i_mode);
1032 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
1033 			  sizeof(value), 0, true);
1034 	if (err)
1035 		goto out;
1036 
1037 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1038 		value = cpu_to_le32(inode->i_rdev);
1039 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
1040 				  sizeof(value), 0, true);
1041 		if (err)
1042 			goto out;
1043 	}
1044 
1045 out:
1046 	ni_unlock(ni);
1047 	/* In case of error should we delete all WSL xattr? */
1048 	return err;
1049 }
1050 
1051 /*
1052  * ntfs_get_wsl_perm
1053  *
1054  * get uid/gid/mode from xattr
1055  * it is called from ntfs_iget5->ntfs_read_mft
1056  */
1057 void ntfs_get_wsl_perm(struct inode *inode)
1058 {
1059 	size_t sz;
1060 	__le32 value[3];
1061 
1062 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
1063 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
1064 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
1065 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
1066 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
1067 			sizeof(value[2]), &sz) == sizeof(value[2])) {
1068 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
1069 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
1070 		inode->i_mode = le32_to_cpu(value[2]);
1071 
1072 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
1073 				&value[0], sizeof(value),
1074 				&sz) == sizeof(value[0])) {
1075 			inode->i_rdev = le32_to_cpu(value[0]);
1076 		}
1077 	}
1078 }
1079 
1080 static bool ntfs_xattr_user_list(struct dentry *dentry)
1081 {
1082 	return true;
1083 }
1084 
1085 // clang-format off
1086 static const struct xattr_handler ntfs_xattr_handler = {
1087 	.prefix	= "",
1088 	.get	= ntfs_getxattr,
1089 	.set	= ntfs_setxattr,
1090 	.list	= ntfs_xattr_user_list,
1091 };
1092 
1093 const struct xattr_handler *ntfs_xattr_handlers[] = {
1094 	&ntfs_xattr_handler,
1095 	NULL,
1096 };
1097 // clang-format on
1098