xref: /linux/fs/ntfs3/xattr.c (revision 559e608c46553c107dbba19dae0854af7b219400)
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 	u32 off, size;
199 	int err;
200 	size_t ret;
201 
202 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
203 	if (err)
204 		return err;
205 
206 	if (!info || !ea_all)
207 		return 0;
208 
209 	size = le32_to_cpu(info->size);
210 
211 	/* Enumerate all xattrs. */
212 	ret = 0;
213 	off = 0;
214 	while (off + sizeof(struct EA_FULL) < size) {
215 		const struct EA_FULL *ea = Add2Ptr(ea_all, off);
216 		int ea_size = unpacked_ea_size(ea);
217 		u8 name_len = ea->name_len;
218 
219 		if (!name_len)
220 			break;
221 
222 		if (name_len > ea_size) {
223 			ntfs_set_state(ni->mi.sbi, NTFS_DIRTY_ERROR);
224 			err = -EINVAL; /* corrupted fs. */
225 			break;
226 		}
227 
228 		if (buffer) {
229 			/* Check if we can use field ea->name */
230 			if (off + ea_size > size)
231 				break;
232 
233 			if (ret + name_len + 1 > bytes_per_buffer) {
234 				err = -ERANGE;
235 				goto out;
236 			}
237 
238 			memcpy(buffer + ret, ea->name, name_len);
239 			buffer[ret + name_len] = 0;
240 		}
241 
242 		ret += name_len + 1;
243 		off += ea_size;
244 	}
245 
246 out:
247 	kfree(ea_all);
248 	return err ? err : ret;
249 }
250 
251 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
252 		       void *buffer, size_t size, size_t *required)
253 {
254 	struct ntfs_inode *ni = ntfs_i(inode);
255 	const struct EA_INFO *info;
256 	struct EA_FULL *ea_all = NULL;
257 	const struct EA_FULL *ea;
258 	u32 off, len;
259 	int err;
260 
261 	if (!(ni->ni_flags & NI_FLAG_EA))
262 		return -ENODATA;
263 
264 	if (!required)
265 		ni_lock(ni);
266 
267 	len = 0;
268 
269 	if (name_len > 255) {
270 		err = -ENAMETOOLONG;
271 		goto out;
272 	}
273 
274 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
275 	if (err)
276 		goto out;
277 
278 	if (!info)
279 		goto out;
280 
281 	/* Enumerate all xattrs. */
282 	if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, &off,
283 		     NULL)) {
284 		err = -ENODATA;
285 		goto out;
286 	}
287 	ea = Add2Ptr(ea_all, off);
288 
289 	len = le16_to_cpu(ea->elength);
290 	if (!buffer) {
291 		err = 0;
292 		goto out;
293 	}
294 
295 	if (len > size) {
296 		err = -ERANGE;
297 		if (required)
298 			*required = len;
299 		goto out;
300 	}
301 
302 	memcpy(buffer, ea->name + ea->name_len + 1, len);
303 	err = 0;
304 
305 out:
306 	kfree(ea_all);
307 	if (!required)
308 		ni_unlock(ni);
309 
310 	return err ? err : len;
311 }
312 
313 static noinline int ntfs_set_ea(struct inode *inode, const char *name,
314 				size_t name_len, const void *value,
315 				size_t val_size, int flags, bool locked,
316 				__le32 *ea_size)
317 {
318 	struct ntfs_inode *ni = ntfs_i(inode);
319 	struct ntfs_sb_info *sbi = ni->mi.sbi;
320 	int err;
321 	struct EA_INFO ea_info;
322 	const struct EA_INFO *info;
323 	struct EA_FULL *new_ea;
324 	struct EA_FULL *ea_all = NULL;
325 	size_t add, new_pack;
326 	u32 off, size, ea_sz;
327 	__le16 size_pack;
328 	struct ATTRIB *attr;
329 	struct ATTR_LIST_ENTRY *le;
330 	struct mft_inode *mi;
331 	struct runs_tree ea_run;
332 	u64 new_sz;
333 	void *p;
334 
335 	if (!locked)
336 		ni_lock(ni);
337 
338 	run_init(&ea_run);
339 
340 	if (name_len > 255) {
341 		err = -ENAMETOOLONG;
342 		goto out;
343 	}
344 
345 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
346 
347 	err = ntfs_read_ea(ni, &ea_all, add, &info);
348 	if (err)
349 		goto out;
350 
351 	if (!info) {
352 		memset(&ea_info, 0, sizeof(ea_info));
353 		size = 0;
354 		size_pack = 0;
355 	} else {
356 		memcpy(&ea_info, info, sizeof(ea_info));
357 		size = le32_to_cpu(ea_info.size);
358 		size_pack = ea_info.size_pack;
359 	}
360 
361 	if (info && find_ea(ea_all, size, name, name_len, &off, &ea_sz)) {
362 		struct EA_FULL *ea;
363 
364 		if (flags & XATTR_CREATE) {
365 			err = -EEXIST;
366 			goto out;
367 		}
368 
369 		ea = Add2Ptr(ea_all, off);
370 
371 		/*
372 		 * Check simple case when we try to insert xattr with the same value
373 		 * e.g. ntfs_save_wsl_perm
374 		 */
375 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
376 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
377 			/* xattr already contains the required value. */
378 			goto out;
379 		}
380 
381 		/* Remove current xattr. */
382 		if (ea->flags & FILE_NEED_EA)
383 			le16_add_cpu(&ea_info.count, -1);
384 
385 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
386 
387 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
388 
389 		size -= ea_sz;
390 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
391 
392 		ea_info.size = cpu_to_le32(size);
393 
394 		if ((flags & XATTR_REPLACE) && !val_size) {
395 			/* Remove xattr. */
396 			goto update_ea;
397 		}
398 	} else {
399 		if (flags & XATTR_REPLACE) {
400 			err = -ENODATA;
401 			goto out;
402 		}
403 
404 		if (!ea_all) {
405 			ea_all = kzalloc(add, GFP_NOFS);
406 			if (!ea_all) {
407 				err = -ENOMEM;
408 				goto out;
409 			}
410 		}
411 	}
412 
413 	/* Append new xattr. */
414 	new_ea = Add2Ptr(ea_all, size);
415 	new_ea->size = cpu_to_le32(add);
416 	new_ea->flags = 0;
417 	new_ea->name_len = name_len;
418 	new_ea->elength = cpu_to_le16(val_size);
419 	memcpy(new_ea->name, name, name_len);
420 	new_ea->name[name_len] = 0;
421 	memcpy(new_ea->name + name_len + 1, value, val_size);
422 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
423 	ea_info.size_pack = cpu_to_le16(new_pack);
424 	/* New size of ATTR_EA. */
425 	size += add;
426 	ea_info.size = cpu_to_le32(size);
427 
428 	/*
429 	 * 1. Check ea_info.size_pack for overflow.
430 	 * 2. New attribute size must fit value from $AttrDef
431 	 */
432 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
433 		ntfs_inode_warn(
434 			inode,
435 			"The size of extended attributes must not exceed 64KiB");
436 		err = -EFBIG; // -EINVAL?
437 		goto out;
438 	}
439 
440 update_ea:
441 
442 	if (!info) {
443 		/* Create xattr. */
444 		if (!size) {
445 			err = 0;
446 			goto out;
447 		}
448 
449 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
450 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
451 					 NULL);
452 		if (err)
453 			goto out;
454 
455 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
456 					 NULL);
457 		if (err)
458 			goto out;
459 	}
460 
461 	new_sz = size;
462 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
463 			    false, NULL);
464 	if (err)
465 		goto out;
466 
467 	le = NULL;
468 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
469 	if (!attr) {
470 		err = -EINVAL;
471 		goto out;
472 	}
473 
474 	if (!size) {
475 		/* Delete xattr, ATTR_EA_INFO */
476 		ni_remove_attr_le(ni, attr, mi, le);
477 	} else {
478 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
479 		if (!p) {
480 			err = -EINVAL;
481 			goto out;
482 		}
483 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
484 		mi->dirty = true;
485 	}
486 
487 	le = NULL;
488 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
489 	if (!attr) {
490 		err = -EINVAL;
491 		goto out;
492 	}
493 
494 	if (!size) {
495 		/* Delete xattr, ATTR_EA */
496 		ni_remove_attr_le(ni, attr, mi, le);
497 	} else if (attr->non_res) {
498 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
499 					   size);
500 		if (err)
501 			goto out;
502 
503 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
504 		if (err)
505 			goto out;
506 	} else {
507 		p = resident_data_ex(attr, size);
508 		if (!p) {
509 			err = -EINVAL;
510 			goto out;
511 		}
512 		memcpy(p, ea_all, size);
513 		mi->dirty = true;
514 	}
515 
516 	/* Check if we delete the last xattr. */
517 	if (size)
518 		ni->ni_flags |= NI_FLAG_EA;
519 	else
520 		ni->ni_flags &= ~NI_FLAG_EA;
521 
522 	if (ea_info.size_pack != size_pack)
523 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
524 	if (ea_size)
525 		*ea_size = ea_info.size;
526 	mark_inode_dirty(&ni->vfs_inode);
527 
528 out:
529 	if (!locked)
530 		ni_unlock(ni);
531 
532 	run_close(&ea_run);
533 	kfree(ea_all);
534 
535 	return err;
536 }
537 
538 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
539 
540 /*
541  * ntfs_get_acl - inode_operations::get_acl
542  */
543 struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
544 			       int type)
545 {
546 	struct inode *inode = d_inode(dentry);
547 	struct ntfs_inode *ni = ntfs_i(inode);
548 	const char *name;
549 	size_t name_len;
550 	struct posix_acl *acl;
551 	size_t req;
552 	int err;
553 	void *buf;
554 
555 	/* Avoid any operation if inode is bad. */
556 	if (unlikely(is_bad_ni(ni)))
557 		return ERR_PTR(-EINVAL);
558 
559 	/* Allocate PATH_MAX bytes. */
560 	buf = __getname();
561 	if (!buf)
562 		return ERR_PTR(-ENOMEM);
563 
564 	/* Possible values of 'type' was already checked above. */
565 	if (type == ACL_TYPE_ACCESS) {
566 		name = XATTR_NAME_POSIX_ACL_ACCESS;
567 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
568 	} else {
569 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
570 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
571 	}
572 
573 	ni_lock(ni);
574 
575 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
576 
577 	ni_unlock(ni);
578 
579 	/* Translate extended attribute to acl. */
580 	if (err >= 0) {
581 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
582 	} else if (err == -ENODATA) {
583 		acl = NULL;
584 	} else {
585 		acl = ERR_PTR(err);
586 	}
587 
588 	if (!IS_ERR(acl))
589 		set_cached_acl(inode, type, acl);
590 
591 	__putname(buf);
592 
593 	return acl;
594 }
595 
596 static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
597 				    struct inode *inode, struct posix_acl *acl,
598 				    int type, bool init_acl)
599 {
600 	const char *name;
601 	size_t size, name_len;
602 	void *value;
603 	int err;
604 	int flags;
605 	umode_t mode;
606 
607 	/* Avoid any operation if inode is bad. */
608 	if (unlikely(is_bad_ni(ntfs_i(inode))))
609 		return -EINVAL;
610 
611 	if (S_ISLNK(inode->i_mode))
612 		return -EOPNOTSUPP;
613 
614 	mode = inode->i_mode;
615 	switch (type) {
616 	case ACL_TYPE_ACCESS:
617 		/* Do not change i_mode if we are in init_acl */
618 		if (acl && !init_acl) {
619 			err = posix_acl_update_mode(idmap, inode, &mode, &acl);
620 			if (err)
621 				return err;
622 		}
623 		name = XATTR_NAME_POSIX_ACL_ACCESS;
624 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
625 		break;
626 
627 	case ACL_TYPE_DEFAULT:
628 		if (!S_ISDIR(inode->i_mode))
629 			return acl ? -EACCES : 0;
630 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
631 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
632 		break;
633 
634 	default:
635 		return -EINVAL;
636 	}
637 
638 	if (!acl) {
639 		/* Remove xattr if it can be presented via mode. */
640 		size = 0;
641 		value = NULL;
642 		flags = XATTR_REPLACE;
643 	} else {
644 		size = posix_acl_xattr_size(acl->a_count);
645 		value = kmalloc(size, GFP_NOFS);
646 		if (!value)
647 			return -ENOMEM;
648 		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
649 		if (err < 0)
650 			goto out;
651 		flags = 0;
652 	}
653 
654 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0, NULL);
655 	if (err == -ENODATA && !size)
656 		err = 0; /* Removing non existed xattr. */
657 	if (err)
658 		goto out;
659 
660 	if (inode->i_mode != mode) {
661 		umode_t old_mode = inode->i_mode;
662 		inode->i_mode = mode;
663 		err = ntfs_save_wsl_perm(inode, NULL);
664 		if (err) {
665 			inode->i_mode = old_mode;
666 			goto out;
667 		}
668 		inode->i_mode = mode;
669 	}
670 	set_cached_acl(inode, type, acl);
671 	inode_set_ctime_current(inode);
672 	mark_inode_dirty(inode);
673 
674 out:
675 	kfree(value);
676 
677 	return err;
678 }
679 
680 /*
681  * ntfs_set_acl - inode_operations::set_acl
682  */
683 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
684 		 struct posix_acl *acl, int type)
685 {
686 	return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
687 }
688 
689 /*
690  * ntfs_init_acl - Initialize the ACLs of a new inode.
691  *
692  * Called from ntfs_create_inode().
693  */
694 int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
695 		  struct inode *dir)
696 {
697 	struct posix_acl *default_acl, *acl;
698 	int err;
699 
700 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
701 	if (err)
702 		return err;
703 
704 	if (default_acl) {
705 		err = ntfs_set_acl_ex(idmap, inode, default_acl,
706 				      ACL_TYPE_DEFAULT, true);
707 		posix_acl_release(default_acl);
708 	} else {
709 		inode->i_default_acl = NULL;
710 	}
711 
712 	if (acl) {
713 		if (!err)
714 			err = ntfs_set_acl_ex(idmap, inode, acl,
715 					      ACL_TYPE_ACCESS, true);
716 		posix_acl_release(acl);
717 	} else {
718 		inode->i_acl = NULL;
719 	}
720 
721 	return err;
722 }
723 #endif
724 
725 /*
726  * ntfs_acl_chmod - Helper for ntfs_setattr().
727  */
728 int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
729 {
730 	struct inode *inode = d_inode(dentry);
731 	struct super_block *sb = inode->i_sb;
732 
733 	if (!(sb->s_flags & SB_POSIXACL))
734 		return 0;
735 
736 	if (S_ISLNK(inode->i_mode))
737 		return -EOPNOTSUPP;
738 
739 	return posix_acl_chmod(idmap, dentry, inode->i_mode);
740 }
741 
742 /*
743  * ntfs_listxattr - inode_operations::listxattr
744  */
745 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
746 {
747 	struct inode *inode = d_inode(dentry);
748 	struct ntfs_inode *ni = ntfs_i(inode);
749 	ssize_t ret;
750 
751 	/* Avoid any operation if inode is bad. */
752 	if (unlikely(is_bad_ni(ni)))
753 		return -EINVAL;
754 
755 	if (!(ni->ni_flags & NI_FLAG_EA)) {
756 		/* no xattr in file */
757 		return 0;
758 	}
759 
760 	ni_lock(ni);
761 
762 	ret = ntfs_list_ea(ni, buffer, size);
763 
764 	ni_unlock(ni);
765 
766 	return ret;
767 }
768 
769 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
770 			 struct inode *inode, const char *name, void *buffer,
771 			 size_t size)
772 {
773 	int err;
774 	struct ntfs_inode *ni = ntfs_i(inode);
775 
776 	/* Avoid any operation if inode is bad. */
777 	if (unlikely(is_bad_ni(ni)))
778 		return -EINVAL;
779 
780 	if (unlikely(ntfs3_forced_shutdown(inode->i_sb)))
781 		return -EIO;
782 
783 	/* Dispatch request. */
784 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
785 		/* system.dos_attrib */
786 		if (!buffer) {
787 			err = sizeof(u8);
788 		} else if (size < sizeof(u8)) {
789 			err = -ENODATA;
790 		} else {
791 			err = sizeof(u8);
792 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
793 		}
794 		goto out;
795 	}
796 
797 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
798 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
799 		/* system.ntfs_attrib */
800 		if (!buffer) {
801 			err = sizeof(u32);
802 		} else if (size < sizeof(u32)) {
803 			err = -ENODATA;
804 		} else {
805 			err = sizeof(u32);
806 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
807 			if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
808 				*(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
809 		}
810 		goto out;
811 	}
812 
813 	if (!strcmp(name, 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 	/* Deal with NTFS extended attribute. */
853 	err = ntfs_get_ea(inode, name, strlen(name), buffer, size, NULL);
854 
855 out:
856 	return err;
857 }
858 
859 /*
860  * ntfs_setxattr - inode_operations::setxattr
861  */
862 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
863 				  struct mnt_idmap *idmap, struct dentry *de,
864 				  struct inode *inode, const char *name,
865 				  const void *value, size_t size, int flags)
866 {
867 	int err = -EINVAL;
868 	struct ntfs_inode *ni = ntfs_i(inode);
869 	enum FILE_ATTRIBUTE new_fa;
870 
871 	/* Dispatch request. */
872 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
873 		if (sizeof(u8) != size)
874 			goto out;
875 		new_fa = cpu_to_le32(*(u8 *)value);
876 		goto set_new_fa;
877 	}
878 
879 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
880 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
881 		if (size != sizeof(u32))
882 			goto out;
883 		if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
884 			new_fa = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
885 		else
886 			new_fa = cpu_to_le32(*(u32 *)value);
887 
888 		if (S_ISREG(inode->i_mode)) {
889 			/* Process compressed/sparsed in special way. */
890 			ni_lock(ni);
891 			err = ni_new_attr_flags(ni, new_fa);
892 			ni_unlock(ni);
893 			if (err)
894 				goto out;
895 		}
896 set_new_fa:
897 		/*
898 		 * Thanks Mark Harmstone:
899 		 * Keep directory bit consistency.
900 		 */
901 		if (S_ISDIR(inode->i_mode))
902 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
903 		else
904 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
905 
906 		if (ni->std_fa != new_fa) {
907 			ni->std_fa = new_fa;
908 			if (new_fa & FILE_ATTRIBUTE_READONLY)
909 				inode->i_mode &= ~0222;
910 			else
911 				inode->i_mode |= 0222;
912 			/* Std attribute always in primary record. */
913 			ni->mi.dirty = true;
914 			mark_inode_dirty(inode);
915 		}
916 		err = 0;
917 
918 		goto out;
919 	}
920 
921 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
922 		/* system.ntfs_security*/
923 		__le32 security_id;
924 		bool inserted;
925 		struct ATTR_STD_INFO5 *std;
926 
927 		if (!is_ntfs3(ni->mi.sbi)) {
928 			/*
929 			 * We should replace ATTR_SECURE.
930 			 * Skip this way cause it is nt4 feature.
931 			 */
932 			err = -EINVAL;
933 			goto out;
934 		}
935 
936 		if (!is_sd_valid(value, size)) {
937 			err = -EINVAL;
938 			ntfs_inode_warn(
939 				inode,
940 				"you try to set invalid security descriptor");
941 			goto out;
942 		}
943 
944 		err = ntfs_insert_security(ni->mi.sbi, value, size,
945 					   &security_id, &inserted);
946 		if (err)
947 			goto out;
948 
949 		ni_lock(ni);
950 		std = ni_std5(ni);
951 		if (!std) {
952 			err = -EINVAL;
953 		} else if (std->security_id != security_id) {
954 			std->security_id = ni->std_security_id = security_id;
955 			/* Std attribute always in primary record. */
956 			ni->mi.dirty = true;
957 			mark_inode_dirty(&ni->vfs_inode);
958 		}
959 		ni_unlock(ni);
960 		goto out;
961 	}
962 
963 	/* Deal with NTFS extended attribute. */
964 	err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, 0,
965 			  NULL);
966 
967 out:
968 	inode_set_ctime_current(inode);
969 	mark_inode_dirty(inode);
970 
971 	return err;
972 }
973 
974 /*
975  * ntfs_save_wsl_perm
976  *
977  * save uid/gid/mode in xattr
978  */
979 int ntfs_save_wsl_perm(struct inode *inode, __le32 *ea_size)
980 {
981 	int err;
982 	__le32 value;
983 	struct ntfs_inode *ni = ntfs_i(inode);
984 
985 	ni_lock(ni);
986 	value = cpu_to_le32(i_uid_read(inode));
987 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
988 			  sizeof(value), 0, true, ea_size);
989 	if (err)
990 		goto out;
991 
992 	value = cpu_to_le32(i_gid_read(inode));
993 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
994 			  sizeof(value), 0, true, ea_size);
995 	if (err)
996 		goto out;
997 
998 	value = cpu_to_le32(inode->i_mode);
999 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
1000 			  sizeof(value), 0, true, ea_size);
1001 	if (err)
1002 		goto out;
1003 
1004 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1005 		value = cpu_to_le32(inode->i_rdev);
1006 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
1007 				  sizeof(value), 0, true, ea_size);
1008 		if (err)
1009 			goto out;
1010 	}
1011 
1012 out:
1013 	ni_unlock(ni);
1014 	/* In case of error should we delete all WSL xattr? */
1015 	return err;
1016 }
1017 
1018 /*
1019  * ntfs_get_wsl_perm
1020  *
1021  * get uid/gid/mode from xattr
1022  * it is called from ntfs_iget5->ntfs_read_mft
1023  */
1024 void ntfs_get_wsl_perm(struct inode *inode)
1025 {
1026 	size_t sz;
1027 	__le32 value[3];
1028 
1029 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
1030 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
1031 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
1032 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
1033 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
1034 			sizeof(value[2]), &sz) == sizeof(value[2])) {
1035 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
1036 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
1037 		inode->i_mode = le32_to_cpu(value[2]);
1038 
1039 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
1040 				&value[0], sizeof(value),
1041 				&sz) == sizeof(value[0])) {
1042 			inode->i_rdev = le32_to_cpu(value[0]);
1043 		}
1044 	}
1045 }
1046 
1047 static bool ntfs_xattr_user_list(struct dentry *dentry)
1048 {
1049 	return true;
1050 }
1051 
1052 // clang-format off
1053 static const struct xattr_handler ntfs_other_xattr_handler = {
1054 	.prefix	= "",
1055 	.get	= ntfs_getxattr,
1056 	.set	= ntfs_setxattr,
1057 	.list	= ntfs_xattr_user_list,
1058 };
1059 
1060 const struct xattr_handler * const ntfs_xattr_handlers[] = {
1061 	&ntfs_other_xattr_handler,
1062 	NULL,
1063 };
1064 // clang-format on
1065