xref: /openbmc/linux/fs/ntfs3/xattr.c (revision 3fc7c707)
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_ATTRIB_BE "system.ntfs_attrib_be"
21 #define SYSTEM_NTFS_SECURITY  "system.ntfs_security"
22 // clang-format on
23 
24 static inline size_t unpacked_ea_size(const struct EA_FULL *ea)
25 {
26 	return ea->size ? le32_to_cpu(ea->size) :
27 			  ALIGN(struct_size(ea, name,
28 					    1 + ea->name_len +
29 						    le16_to_cpu(ea->elength)),
30 				4);
31 }
32 
33 static inline size_t packed_ea_size(const struct EA_FULL *ea)
34 {
35 	return struct_size(ea, name,
36 			   1 + ea->name_len + le16_to_cpu(ea->elength)) -
37 	       offsetof(struct EA_FULL, flags);
38 }
39 
40 /*
41  * find_ea
42  *
43  * Assume there is at least one xattr in the list.
44  */
45 static inline bool find_ea(const struct EA_FULL *ea_all, u32 bytes,
46 			   const char *name, u8 name_len, u32 *off, u32 *ea_sz)
47 {
48 	u32 ea_size;
49 
50 	*off = 0;
51 	if (!ea_all)
52 		return false;
53 
54 	for (; *off < bytes; *off += ea_size) {
55 		const struct EA_FULL *ea = Add2Ptr(ea_all, *off);
56 		ea_size = unpacked_ea_size(ea);
57 		if (ea->name_len == name_len &&
58 		    !memcmp(ea->name, name, name_len)) {
59 			if (ea_sz)
60 				*ea_sz = ea_size;
61 			return true;
62 		}
63 	}
64 
65 	return false;
66 }
67 
68 /*
69  * ntfs_read_ea - Read all extended attributes.
70  * @ea:		New allocated memory.
71  * @info:	Pointer into resident data.
72  */
73 static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
74 			size_t add_bytes, const struct EA_INFO **info)
75 {
76 	int err = -EINVAL;
77 	struct ntfs_sb_info *sbi = ni->mi.sbi;
78 	struct ATTR_LIST_ENTRY *le = NULL;
79 	struct ATTRIB *attr_info, *attr_ea;
80 	void *ea_p;
81 	u32 size, off, ea_size;
82 
83 	static_assert(le32_to_cpu(ATTR_EA_INFO) < le32_to_cpu(ATTR_EA));
84 
85 	*ea = NULL;
86 	*info = NULL;
87 
88 	attr_info =
89 		ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, NULL);
90 	attr_ea =
91 		ni_find_attr(ni, attr_info, &le, ATTR_EA, NULL, 0, NULL, NULL);
92 
93 	if (!attr_ea || !attr_info)
94 		return 0;
95 
96 	*info = resident_data_ex(attr_info, sizeof(struct EA_INFO));
97 	if (!*info)
98 		goto out;
99 
100 	/* Check Ea limit. */
101 	size = le32_to_cpu((*info)->size);
102 	if (size > sbi->ea_max_size) {
103 		err = -EFBIG;
104 		goto out;
105 	}
106 
107 	if (attr_size(attr_ea) > sbi->ea_max_size) {
108 		err = -EFBIG;
109 		goto out;
110 	}
111 
112 	if (!size) {
113 		/* EA info persists, but xattr is empty. Looks like EA problem. */
114 		goto out;
115 	}
116 
117 	/* Allocate memory for packed Ea. */
118 	ea_p = kmalloc(size_add(size, add_bytes), GFP_NOFS);
119 	if (!ea_p)
120 		return -ENOMEM;
121 
122 	if (attr_ea->non_res) {
123 		struct runs_tree run;
124 
125 		run_init(&run);
126 
127 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &run, 0, size);
128 		if (!err)
129 			err = ntfs_read_run_nb(sbi, &run, 0, ea_p, size, NULL);
130 		run_close(&run);
131 
132 		if (err)
133 			goto out1;
134 	} else {
135 		void *p = resident_data_ex(attr_ea, size);
136 
137 		if (!p)
138 			goto out1;
139 		memcpy(ea_p, p, size);
140 	}
141 
142 	memset(Add2Ptr(ea_p, size), 0, add_bytes);
143 
144 	err = -EINVAL;
145 	/* Check all attributes for consistency. */
146 	for (off = 0; off < size; off += ea_size) {
147 		const struct EA_FULL *ef = Add2Ptr(ea_p, off);
148 		u32 bytes = size - off;
149 
150 		/* Check if we can use field ea->size. */
151 		if (bytes < sizeof(ef->size))
152 			goto out1;
153 
154 		if (ef->size) {
155 			ea_size = le32_to_cpu(ef->size);
156 			if (ea_size > bytes)
157 				goto out1;
158 			continue;
159 		}
160 
161 		/* Check if we can use fields ef->name_len and ef->elength. */
162 		if (bytes < offsetof(struct EA_FULL, name))
163 			goto out1;
164 
165 		ea_size = ALIGN(struct_size(ef, name,
166 					    1 + ef->name_len +
167 						    le16_to_cpu(ef->elength)),
168 				4);
169 		if (ea_size > bytes)
170 			goto out1;
171 	}
172 
173 	*ea = ea_p;
174 	return 0;
175 
176 out1:
177 	kfree(ea_p);
178 out:
179 	ntfs_set_state(sbi, NTFS_DIRTY_DIRTY);
180 	return err;
181 }
182 
183 /*
184  * ntfs_list_ea
185  *
186  * Copy a list of xattrs names into the buffer
187  * provided, or compute the buffer size required.
188  *
189  * Return:
190  * * Number of bytes used / required on
191  * * -ERRNO - on failure
192  */
193 static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
194 			    size_t bytes_per_buffer)
195 {
196 	const struct EA_INFO *info;
197 	struct EA_FULL *ea_all = NULL;
198 	const struct EA_FULL *ea;
199 	u32 off, size;
200 	int err;
201 	int ea_size;
202 	size_t ret;
203 
204 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
205 	if (err)
206 		return err;
207 
208 	if (!info || !ea_all)
209 		return 0;
210 
211 	size = le32_to_cpu(info->size);
212 
213 	/* Enumerate all xattrs. */
214 	ret = 0;
215 	for (off = 0; off + sizeof(struct EA_FULL) < size; off += ea_size) {
216 		ea = Add2Ptr(ea_all, off);
217 		ea_size = unpacked_ea_size(ea);
218 
219 		if (!ea->name_len)
220 			break;
221 
222 		if (buffer) {
223 			/* Check if we can use field ea->name */
224 			if (off + ea_size > size)
225 				break;
226 
227 			if (ret + ea->name_len + 1 > bytes_per_buffer) {
228 				err = -ERANGE;
229 				goto out;
230 			}
231 
232 			memcpy(buffer + ret, ea->name, ea->name_len);
233 			buffer[ret + ea->name_len] = 0;
234 		}
235 
236 		ret += ea->name_len + 1;
237 	}
238 
239 out:
240 	kfree(ea_all);
241 	return err ? err : ret;
242 }
243 
244 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
245 		       void *buffer, size_t size, size_t *required)
246 {
247 	struct ntfs_inode *ni = ntfs_i(inode);
248 	const struct EA_INFO *info;
249 	struct EA_FULL *ea_all = NULL;
250 	const struct EA_FULL *ea;
251 	u32 off, len;
252 	int err;
253 
254 	if (!(ni->ni_flags & NI_FLAG_EA))
255 		return -ENODATA;
256 
257 	if (!required)
258 		ni_lock(ni);
259 
260 	len = 0;
261 
262 	if (name_len > 255) {
263 		err = -ENAMETOOLONG;
264 		goto out;
265 	}
266 
267 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
268 	if (err)
269 		goto out;
270 
271 	if (!info)
272 		goto out;
273 
274 	/* Enumerate all xattrs. */
275 	if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, &off,
276 		     NULL)) {
277 		err = -ENODATA;
278 		goto out;
279 	}
280 	ea = Add2Ptr(ea_all, off);
281 
282 	len = le16_to_cpu(ea->elength);
283 	if (!buffer) {
284 		err = 0;
285 		goto out;
286 	}
287 
288 	if (len > size) {
289 		err = -ERANGE;
290 		if (required)
291 			*required = len;
292 		goto out;
293 	}
294 
295 	memcpy(buffer, ea->name + ea->name_len + 1, len);
296 	err = 0;
297 
298 out:
299 	kfree(ea_all);
300 	if (!required)
301 		ni_unlock(ni);
302 
303 	return err ? err : len;
304 }
305 
306 static noinline int ntfs_set_ea(struct inode *inode, const char *name,
307 				size_t name_len, const void *value,
308 				size_t val_size, int flags, bool locked,
309 				__le16 *ea_size)
310 {
311 	struct ntfs_inode *ni = ntfs_i(inode);
312 	struct ntfs_sb_info *sbi = ni->mi.sbi;
313 	int err;
314 	struct EA_INFO ea_info;
315 	const struct EA_INFO *info;
316 	struct EA_FULL *new_ea;
317 	struct EA_FULL *ea_all = NULL;
318 	size_t add, new_pack;
319 	u32 off, size, ea_sz;
320 	__le16 size_pack;
321 	struct ATTRIB *attr;
322 	struct ATTR_LIST_ENTRY *le;
323 	struct mft_inode *mi;
324 	struct runs_tree ea_run;
325 	u64 new_sz;
326 	void *p;
327 
328 	if (!locked)
329 		ni_lock(ni);
330 
331 	run_init(&ea_run);
332 
333 	if (name_len > 255) {
334 		err = -ENAMETOOLONG;
335 		goto out;
336 	}
337 
338 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
339 
340 	err = ntfs_read_ea(ni, &ea_all, add, &info);
341 	if (err)
342 		goto out;
343 
344 	if (!info) {
345 		memset(&ea_info, 0, sizeof(ea_info));
346 		size = 0;
347 		size_pack = 0;
348 	} else {
349 		memcpy(&ea_info, info, sizeof(ea_info));
350 		size = le32_to_cpu(ea_info.size);
351 		size_pack = ea_info.size_pack;
352 	}
353 
354 	if (info && find_ea(ea_all, size, name, name_len, &off, &ea_sz)) {
355 		struct EA_FULL *ea;
356 
357 		if (flags & XATTR_CREATE) {
358 			err = -EEXIST;
359 			goto out;
360 		}
361 
362 		ea = Add2Ptr(ea_all, off);
363 
364 		/*
365 		 * Check simple case when we try to insert xattr with the same value
366 		 * e.g. ntfs_save_wsl_perm
367 		 */
368 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
369 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
370 			/* xattr already contains the required value. */
371 			goto out;
372 		}
373 
374 		/* Remove current xattr. */
375 		if (ea->flags & FILE_NEED_EA)
376 			le16_add_cpu(&ea_info.count, -1);
377 
378 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
379 
380 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
381 
382 		size -= ea_sz;
383 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
384 
385 		ea_info.size = cpu_to_le32(size);
386 
387 		if ((flags & XATTR_REPLACE) && !val_size) {
388 			/* Remove xattr. */
389 			goto update_ea;
390 		}
391 	} else {
392 		if (flags & XATTR_REPLACE) {
393 			err = -ENODATA;
394 			goto out;
395 		}
396 
397 		if (!ea_all) {
398 			ea_all = kzalloc(add, GFP_NOFS);
399 			if (!ea_all) {
400 				err = -ENOMEM;
401 				goto out;
402 			}
403 		}
404 	}
405 
406 	/* Append new xattr. */
407 	new_ea = Add2Ptr(ea_all, size);
408 	new_ea->size = cpu_to_le32(add);
409 	new_ea->flags = 0;
410 	new_ea->name_len = name_len;
411 	new_ea->elength = cpu_to_le16(val_size);
412 	memcpy(new_ea->name, name, name_len);
413 	new_ea->name[name_len] = 0;
414 	memcpy(new_ea->name + name_len + 1, value, val_size);
415 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
416 	ea_info.size_pack = cpu_to_le16(new_pack);
417 	/* New size of ATTR_EA. */
418 	size += add;
419 	ea_info.size = cpu_to_le32(size);
420 
421 	/*
422 	 * 1. Check ea_info.size_pack for overflow.
423 	 * 2. New attribute size must fit value from $AttrDef
424 	 */
425 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
426 		ntfs_inode_warn(
427 			inode,
428 			"The size of extended attributes must not exceed 64KiB");
429 		err = -EFBIG; // -EINVAL?
430 		goto out;
431 	}
432 
433 update_ea:
434 
435 	if (!info) {
436 		/* Create xattr. */
437 		if (!size) {
438 			err = 0;
439 			goto out;
440 		}
441 
442 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
443 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
444 					 NULL);
445 		if (err)
446 			goto out;
447 
448 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
449 					 NULL);
450 		if (err)
451 			goto out;
452 	}
453 
454 	new_sz = size;
455 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
456 			    false, NULL);
457 	if (err)
458 		goto out;
459 
460 	le = NULL;
461 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
462 	if (!attr) {
463 		err = -EINVAL;
464 		goto out;
465 	}
466 
467 	if (!size) {
468 		/* Delete xattr, ATTR_EA_INFO */
469 		ni_remove_attr_le(ni, attr, mi, le);
470 	} else {
471 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
472 		if (!p) {
473 			err = -EINVAL;
474 			goto out;
475 		}
476 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
477 		mi->dirty = true;
478 	}
479 
480 	le = NULL;
481 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
482 	if (!attr) {
483 		err = -EINVAL;
484 		goto out;
485 	}
486 
487 	if (!size) {
488 		/* Delete xattr, ATTR_EA */
489 		ni_remove_attr_le(ni, attr, mi, le);
490 	} else if (attr->non_res) {
491 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
492 					   size);
493 		if (err)
494 			goto out;
495 
496 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
497 		if (err)
498 			goto out;
499 	} else {
500 		p = resident_data_ex(attr, size);
501 		if (!p) {
502 			err = -EINVAL;
503 			goto out;
504 		}
505 		memcpy(p, ea_all, size);
506 		mi->dirty = true;
507 	}
508 
509 	/* Check if we delete the last xattr. */
510 	if (size)
511 		ni->ni_flags |= NI_FLAG_EA;
512 	else
513 		ni->ni_flags &= ~NI_FLAG_EA;
514 
515 	if (ea_info.size_pack != size_pack)
516 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
517 	if (ea_size)
518 		*ea_size = ea_info.size_pack;
519 	mark_inode_dirty(&ni->vfs_inode);
520 
521 out:
522 	if (!locked)
523 		ni_unlock(ni);
524 
525 	run_close(&ea_run);
526 	kfree(ea_all);
527 
528 	return err;
529 }
530 
531 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
532 
533 /*
534  * ntfs_get_acl - inode_operations::get_acl
535  */
536 struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
537 			       int type)
538 {
539 	struct inode *inode = d_inode(dentry);
540 	struct ntfs_inode *ni = ntfs_i(inode);
541 	const char *name;
542 	size_t name_len;
543 	struct posix_acl *acl;
544 	size_t req;
545 	int err;
546 	void *buf;
547 
548 	/* Allocate PATH_MAX bytes. */
549 	buf = __getname();
550 	if (!buf)
551 		return ERR_PTR(-ENOMEM);
552 
553 	/* Possible values of 'type' was already checked above. */
554 	if (type == ACL_TYPE_ACCESS) {
555 		name = XATTR_NAME_POSIX_ACL_ACCESS;
556 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
557 	} else {
558 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
559 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
560 	}
561 
562 	ni_lock(ni);
563 
564 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
565 
566 	ni_unlock(ni);
567 
568 	/* Translate extended attribute to acl. */
569 	if (err >= 0) {
570 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
571 	} else if (err == -ENODATA) {
572 		acl = NULL;
573 	} else {
574 		acl = ERR_PTR(err);
575 	}
576 
577 	if (!IS_ERR(acl))
578 		set_cached_acl(inode, type, acl);
579 
580 	__putname(buf);
581 
582 	return acl;
583 }
584 
585 static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
586 				    struct inode *inode, struct posix_acl *acl,
587 				    int type, bool init_acl)
588 {
589 	const char *name;
590 	size_t size, name_len;
591 	void *value;
592 	int err;
593 	int flags;
594 	umode_t mode;
595 
596 	if (S_ISLNK(inode->i_mode))
597 		return -EOPNOTSUPP;
598 
599 	mode = inode->i_mode;
600 	switch (type) {
601 	case ACL_TYPE_ACCESS:
602 		/* Do not change i_mode if we are in init_acl */
603 		if (acl && !init_acl) {
604 			err = posix_acl_update_mode(idmap, inode, &mode, &acl);
605 			if (err)
606 				return err;
607 		}
608 		name = XATTR_NAME_POSIX_ACL_ACCESS;
609 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
610 		break;
611 
612 	case ACL_TYPE_DEFAULT:
613 		if (!S_ISDIR(inode->i_mode))
614 			return acl ? -EACCES : 0;
615 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
616 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
617 		break;
618 
619 	default:
620 		return -EINVAL;
621 	}
622 
623 	if (!acl) {
624 		/* Remove xattr if it can be presented via mode. */
625 		size = 0;
626 		value = NULL;
627 		flags = XATTR_REPLACE;
628 	} else {
629 		size = posix_acl_xattr_size(acl->a_count);
630 		value = kmalloc(size, GFP_NOFS);
631 		if (!value)
632 			return -ENOMEM;
633 		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
634 		if (err < 0)
635 			goto out;
636 		flags = 0;
637 	}
638 
639 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0, NULL);
640 	if (err == -ENODATA && !size)
641 		err = 0; /* Removing non existed xattr. */
642 	if (!err) {
643 		set_cached_acl(inode, type, acl);
644 		inode->i_mode = mode;
645 		inode_set_ctime_current(inode);
646 		mark_inode_dirty(inode);
647 	}
648 
649 out:
650 	kfree(value);
651 
652 	return err;
653 }
654 
655 /*
656  * ntfs_set_acl - inode_operations::set_acl
657  */
658 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
659 		 struct posix_acl *acl, int type)
660 {
661 	return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
662 }
663 
664 /*
665  * ntfs_init_acl - Initialize the ACLs of a new inode.
666  *
667  * Called from ntfs_create_inode().
668  */
669 int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
670 		  struct inode *dir)
671 {
672 	struct posix_acl *default_acl, *acl;
673 	int err;
674 
675 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
676 	if (err)
677 		return err;
678 
679 	if (default_acl) {
680 		err = ntfs_set_acl_ex(idmap, inode, default_acl,
681 				      ACL_TYPE_DEFAULT, true);
682 		posix_acl_release(default_acl);
683 	} else {
684 		inode->i_default_acl = NULL;
685 	}
686 
687 	if (acl) {
688 		if (!err)
689 			err = ntfs_set_acl_ex(idmap, inode, acl,
690 					      ACL_TYPE_ACCESS, true);
691 		posix_acl_release(acl);
692 	} else {
693 		inode->i_acl = NULL;
694 	}
695 
696 	return err;
697 }
698 #endif
699 
700 /*
701  * ntfs_acl_chmod - Helper for ntfs3_setattr().
702  */
703 int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
704 {
705 	struct inode *inode = d_inode(dentry);
706 	struct super_block *sb = inode->i_sb;
707 
708 	if (!(sb->s_flags & SB_POSIXACL))
709 		return 0;
710 
711 	if (S_ISLNK(inode->i_mode))
712 		return -EOPNOTSUPP;
713 
714 	return posix_acl_chmod(idmap, dentry, inode->i_mode);
715 }
716 
717 /*
718  * ntfs_listxattr - inode_operations::listxattr
719  */
720 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
721 {
722 	struct inode *inode = d_inode(dentry);
723 	struct ntfs_inode *ni = ntfs_i(inode);
724 	ssize_t ret;
725 
726 	if (!(ni->ni_flags & NI_FLAG_EA)) {
727 		/* no xattr in file */
728 		return 0;
729 	}
730 
731 	ni_lock(ni);
732 
733 	ret = ntfs_list_ea(ni, buffer, size);
734 
735 	ni_unlock(ni);
736 
737 	return ret;
738 }
739 
740 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
741 			 struct inode *inode, const char *name, void *buffer,
742 			 size_t size)
743 {
744 	int err;
745 	struct ntfs_inode *ni = ntfs_i(inode);
746 
747 	/* Dispatch request. */
748 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
749 		/* system.dos_attrib */
750 		if (!buffer) {
751 			err = sizeof(u8);
752 		} else if (size < sizeof(u8)) {
753 			err = -ENODATA;
754 		} else {
755 			err = sizeof(u8);
756 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
757 		}
758 		goto out;
759 	}
760 
761 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
762 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
763 		/* system.ntfs_attrib */
764 		if (!buffer) {
765 			err = sizeof(u32);
766 		} else if (size < sizeof(u32)) {
767 			err = -ENODATA;
768 		} else {
769 			err = sizeof(u32);
770 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
771 			if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
772 				*(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
773 		}
774 		goto out;
775 	}
776 
777 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
778 		/* system.ntfs_security*/
779 		struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
780 		size_t sd_size = 0;
781 
782 		if (!is_ntfs3(ni->mi.sbi)) {
783 			/* We should get nt4 security. */
784 			err = -EINVAL;
785 			goto out;
786 		} else if (le32_to_cpu(ni->std_security_id) <
787 			   SECURITY_ID_FIRST) {
788 			err = -ENOENT;
789 			goto out;
790 		}
791 
792 		err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
793 					      &sd, &sd_size);
794 		if (err)
795 			goto out;
796 
797 		if (!is_sd_valid(sd, sd_size)) {
798 			ntfs_inode_warn(
799 				inode,
800 				"looks like you get incorrect security descriptor id=%u",
801 				ni->std_security_id);
802 		}
803 
804 		if (!buffer) {
805 			err = sd_size;
806 		} else if (size < sd_size) {
807 			err = -ENODATA;
808 		} else {
809 			err = sd_size;
810 			memcpy(buffer, sd, sd_size);
811 		}
812 		kfree(sd);
813 		goto out;
814 	}
815 
816 	/* Deal with NTFS extended attribute. */
817 	err = ntfs_get_ea(inode, name, strlen(name), buffer, size, NULL);
818 
819 out:
820 	return err;
821 }
822 
823 /*
824  * ntfs_setxattr - inode_operations::setxattr
825  */
826 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
827 				  struct mnt_idmap *idmap, struct dentry *de,
828 				  struct inode *inode, const char *name,
829 				  const void *value, size_t size, int flags)
830 {
831 	int err = -EINVAL;
832 	struct ntfs_inode *ni = ntfs_i(inode);
833 	enum FILE_ATTRIBUTE new_fa;
834 
835 	/* Dispatch request. */
836 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
837 		if (sizeof(u8) != size)
838 			goto out;
839 		new_fa = cpu_to_le32(*(u8 *)value);
840 		goto set_new_fa;
841 	}
842 
843 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
844 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
845 		if (size != sizeof(u32))
846 			goto out;
847 		if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
848 			new_fa = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
849 		else
850 			new_fa = cpu_to_le32(*(u32 *)value);
851 
852 		if (S_ISREG(inode->i_mode)) {
853 			/* Process compressed/sparsed in special way. */
854 			ni_lock(ni);
855 			err = ni_new_attr_flags(ni, new_fa);
856 			ni_unlock(ni);
857 			if (err)
858 				goto out;
859 		}
860 set_new_fa:
861 		/*
862 		 * Thanks Mark Harmstone:
863 		 * Keep directory bit consistency.
864 		 */
865 		if (S_ISDIR(inode->i_mode))
866 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
867 		else
868 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
869 
870 		if (ni->std_fa != new_fa) {
871 			ni->std_fa = new_fa;
872 			if (new_fa & FILE_ATTRIBUTE_READONLY)
873 				inode->i_mode &= ~0222;
874 			else
875 				inode->i_mode |= 0222;
876 			/* Std attribute always in primary record. */
877 			ni->mi.dirty = true;
878 			mark_inode_dirty(inode);
879 		}
880 		err = 0;
881 
882 		goto out;
883 	}
884 
885 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
886 		/* system.ntfs_security*/
887 		__le32 security_id;
888 		bool inserted;
889 		struct ATTR_STD_INFO5 *std;
890 
891 		if (!is_ntfs3(ni->mi.sbi)) {
892 			/*
893 			 * We should replace ATTR_SECURE.
894 			 * Skip this way cause it is nt4 feature.
895 			 */
896 			err = -EINVAL;
897 			goto out;
898 		}
899 
900 		if (!is_sd_valid(value, size)) {
901 			err = -EINVAL;
902 			ntfs_inode_warn(
903 				inode,
904 				"you try to set invalid security descriptor");
905 			goto out;
906 		}
907 
908 		err = ntfs_insert_security(ni->mi.sbi, value, size,
909 					   &security_id, &inserted);
910 		if (err)
911 			goto out;
912 
913 		ni_lock(ni);
914 		std = ni_std5(ni);
915 		if (!std) {
916 			err = -EINVAL;
917 		} else if (std->security_id != security_id) {
918 			std->security_id = ni->std_security_id = security_id;
919 			/* Std attribute always in primary record. */
920 			ni->mi.dirty = true;
921 			mark_inode_dirty(&ni->vfs_inode);
922 		}
923 		ni_unlock(ni);
924 		goto out;
925 	}
926 
927 	/* Deal with NTFS extended attribute. */
928 	err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, 0,
929 			  NULL);
930 
931 out:
932 	inode_set_ctime_current(inode);
933 	mark_inode_dirty(inode);
934 
935 	return err;
936 }
937 
938 /*
939  * ntfs_save_wsl_perm
940  *
941  * save uid/gid/mode in xattr
942  */
943 int ntfs_save_wsl_perm(struct inode *inode, __le16 *ea_size)
944 {
945 	int err;
946 	__le32 value;
947 	struct ntfs_inode *ni = ntfs_i(inode);
948 
949 	ni_lock(ni);
950 	value = cpu_to_le32(i_uid_read(inode));
951 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
952 			  sizeof(value), 0, true, ea_size);
953 	if (err)
954 		goto out;
955 
956 	value = cpu_to_le32(i_gid_read(inode));
957 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
958 			  sizeof(value), 0, true, ea_size);
959 	if (err)
960 		goto out;
961 
962 	value = cpu_to_le32(inode->i_mode);
963 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
964 			  sizeof(value), 0, true, ea_size);
965 	if (err)
966 		goto out;
967 
968 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
969 		value = cpu_to_le32(inode->i_rdev);
970 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
971 				  sizeof(value), 0, true, ea_size);
972 		if (err)
973 			goto out;
974 	}
975 
976 out:
977 	ni_unlock(ni);
978 	/* In case of error should we delete all WSL xattr? */
979 	return err;
980 }
981 
982 /*
983  * ntfs_get_wsl_perm
984  *
985  * get uid/gid/mode from xattr
986  * it is called from ntfs_iget5->ntfs_read_mft
987  */
988 void ntfs_get_wsl_perm(struct inode *inode)
989 {
990 	size_t sz;
991 	__le32 value[3];
992 
993 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
994 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
995 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
996 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
997 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
998 			sizeof(value[2]), &sz) == sizeof(value[2])) {
999 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
1000 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
1001 		inode->i_mode = le32_to_cpu(value[2]);
1002 
1003 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
1004 				&value[0], sizeof(value),
1005 				&sz) == sizeof(value[0])) {
1006 			inode->i_rdev = le32_to_cpu(value[0]);
1007 		}
1008 	}
1009 }
1010 
1011 static bool ntfs_xattr_user_list(struct dentry *dentry)
1012 {
1013 	return true;
1014 }
1015 
1016 // clang-format off
1017 static const struct xattr_handler ntfs_other_xattr_handler = {
1018 	.prefix	= "",
1019 	.get	= ntfs_getxattr,
1020 	.set	= ntfs_setxattr,
1021 	.list	= ntfs_xattr_user_list,
1022 };
1023 
1024 const struct xattr_handler *ntfs_xattr_handlers[] = {
1025 	&ntfs_other_xattr_handler,
1026 	NULL,
1027 };
1028 // clang-format on
1029