xref: /freebsd/sys/fs/ext2fs/ext2_extattr.c (revision 0183e0151669735d62584fbba9125ed90716af5e)
1 /*-
2  * Copyright (c) 2017, Fedor Uporov
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/types.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 #include <sys/vnode.h>
35 #include <sys/bio.h>
36 #include <sys/buf.h>
37 #include <sys/endian.h>
38 #include <sys/conf.h>
39 #include <sys/extattr.h>
40 
41 #include <fs/ext2fs/fs.h>
42 #include <fs/ext2fs/ext2fs.h>
43 #include <fs/ext2fs/inode.h>
44 #include <fs/ext2fs/ext2_dinode.h>
45 #include <fs/ext2fs/ext2_mount.h>
46 #include <fs/ext2fs/ext2_extattr.h>
47 #include <fs/ext2fs/ext2_extern.h>
48 
49 
50 static int
51 ext2_extattr_index_to_bsd(int index)
52 {
53 	switch (index) {
54 		case EXT4_XATTR_INDEX_SYSTEM:
55 			return (EXTATTR_NAMESPACE_SYSTEM);
56 
57 		case EXT4_XATTR_INDEX_USER:
58 			return (EXTATTR_NAMESPACE_USER);
59 	}
60 
61 	return (EXTATTR_NAMESPACE_EMPTY);
62 }
63 
64 static int
65 ext2_extattr_index_to_linux(int index)
66 {
67 	switch (index) {
68 		case EXTATTR_NAMESPACE_SYSTEM:
69 			return (EXT4_XATTR_INDEX_SYSTEM);
70 
71 		case EXTATTR_NAMESPACE_USER:
72 			return (EXT4_XATTR_INDEX_USER);
73 	}
74 
75 	return (-1);
76 }
77 
78 int
79 ext2_extattr_valid_attrname(int attrnamespace, const char *attrname)
80 {
81 	if (attrnamespace == EXTATTR_NAMESPACE_EMPTY)
82 		return (EINVAL);
83 
84 	if (strlen(attrname) == 0)
85 		return (EINVAL);
86 
87 	if (strlen(attrname) + 1 > EXT2_EXTATTR_NAMELEN_MAX)
88 		return (ENAMETOOLONG);
89 
90 	return (0);
91 }
92 
93 static int
94 ext2_extattr_check(struct ext2fs_extattr_entry *entry, char *end)
95 {
96 	struct ext2fs_extattr_entry *next;
97 
98 	while (!EXT2_IS_LAST_ENTRY(entry)) {
99 		next = EXT2_EXTATTR_NEXT(entry);
100 		if ((char *)next >= end)
101 			return (EIO);
102 
103 		entry = next;
104 	}
105 
106 	return (0);
107 }
108 
109 int
110 ext2_extattr_inode_list(struct inode *ip, int attrnamespace,
111     struct uio *uio, size_t *size)
112 {
113 	struct m_ext2fs *fs;
114 	struct buf *bp;
115 	struct ext2fs_extattr_dinode_header *header;
116 	struct ext2fs_extattr_entry *entry;
117 	int error;
118 
119 	fs = ip->i_e2fs;
120 
121 	if ((error = bread(ip->i_devvp,
122 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
123 	    (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
124 		brelse(bp);
125 		return (error);
126 	}
127 
128 	struct ext2fs_dinode *dinode = (struct ext2fs_dinode *)
129 	    ((char *)bp->b_data +
130 	    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number));
131 
132 	/* Check attributes magic value */
133 	header = (struct ext2fs_extattr_dinode_header *)((char *)dinode +
134 	    E2FS_REV0_INODE_SIZE + dinode->e2di_extra_isize);
135 
136 	if (header->h_magic != EXTATTR_MAGIC) {
137 		brelse(bp);
138 		return (0);
139 	}
140 
141 	error = ext2_extattr_check(EXT2_IFIRST(header),
142 	    (char *)dinode + EXT2_INODE_SIZE(fs));
143 	if (error) {
144 		brelse(bp);
145 		return (error);
146 	}
147 
148 	for (entry = EXT2_IFIRST(header); !EXT2_IS_LAST_ENTRY(entry);
149 	    entry = EXT2_EXTATTR_NEXT(entry)) {
150 		if (ext2_extattr_index_to_bsd(entry->e_name_index) != attrnamespace)
151 			continue;
152 
153 		if (uio == NULL)
154 			*size += entry->e_name_len + 1;
155 		else {
156 			char *attr_name = malloc(entry->e_name_len + 1, M_TEMP, M_WAITOK);
157 			attr_name[0] = entry->e_name_len;
158 			memcpy(&attr_name[1], entry->e_name, entry->e_name_len);
159 			error = uiomove(attr_name, entry->e_name_len + 1, uio);
160 			free(attr_name, M_TEMP);
161 			if (error)
162 				break;
163 		}
164 	}
165 
166 	brelse(bp);
167 
168 	return (error);
169 }
170 
171 int
172 ext2_extattr_block_list(struct inode *ip, int attrnamespace,
173     struct uio *uio, size_t *size)
174 {
175 	struct m_ext2fs *fs;
176 	struct buf *bp;
177 	struct ext2fs_extattr_header *header;
178 	struct ext2fs_extattr_entry *entry;
179 	int error;
180 
181 	fs = ip->i_e2fs;
182 
183 	error = bread(ip->i_devvp, fsbtodb(fs, ip->i_facl),
184 	    fs->e2fs_bsize, NOCRED, &bp);
185 	if (error) {
186 		brelse(bp);
187 		return (error);
188 	}
189 
190 	/* Check attributes magic value */
191 	header = EXT2_HDR(bp);
192 	if (header->h_magic != EXTATTR_MAGIC || header->h_blocks != 1) {
193 		brelse(bp);
194 		return (EINVAL);
195 	}
196 
197 	error = ext2_extattr_check(EXT2_FIRST_ENTRY(bp), bp->b_data + bp->b_bufsize);
198 	if (error) {
199 		brelse(bp);
200 		return (error);
201 	}
202 
203 	for (entry = EXT2_FIRST_ENTRY(bp); !EXT2_IS_LAST_ENTRY(entry);
204 	    entry = EXT2_EXTATTR_NEXT(entry)) {
205 		if (ext2_extattr_index_to_bsd(entry->e_name_index) != attrnamespace)
206 			continue;
207 
208 		if (uio == NULL)
209 			*size += entry->e_name_len + 1;
210 		else {
211 			char *attr_name = malloc(entry->e_name_len + 1, M_TEMP, M_WAITOK);
212 			attr_name[0] = entry->e_name_len;
213 			memcpy(&attr_name[1], entry->e_name, entry->e_name_len);
214 			error = uiomove(attr_name, entry->e_name_len + 1, uio);
215 			free(attr_name, M_TEMP);
216 			if (error)
217 				break;
218 		}
219 	}
220 
221 	brelse(bp);
222 
223 	return (error);
224 }
225 
226 int
227 ext2_extattr_inode_get(struct inode *ip, int attrnamespace,
228     const char *name, struct uio *uio, size_t *size)
229 {
230 	struct m_ext2fs *fs;
231 	struct buf *bp;
232 	struct ext2fs_extattr_dinode_header *header;
233 	struct ext2fs_extattr_entry *entry;
234 	int error;
235 
236 	fs = ip->i_e2fs;
237 
238 	if ((error = bread(ip->i_devvp,
239 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
240 	    (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
241 		brelse(bp);
242 		return (error);
243 	}
244 
245 	struct ext2fs_dinode *dinode = (struct ext2fs_dinode *)
246 	    ((char *)bp->b_data +
247 	    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number));
248 
249 	/* Check attributes magic value */
250 	header = (struct ext2fs_extattr_dinode_header *)((char *)dinode +
251 	    E2FS_REV0_INODE_SIZE + dinode->e2di_extra_isize);
252 
253 	if (header->h_magic != EXTATTR_MAGIC) {
254 		brelse(bp);
255 		return (ENOATTR);
256 	}
257 
258 	error = ext2_extattr_check(EXT2_IFIRST(header),
259 	    (char *)dinode + EXT2_INODE_SIZE(fs));
260 	if (error) {
261 		brelse(bp);
262 		return (error);
263 	}
264 
265 	for (entry = EXT2_IFIRST(header); !EXT2_IS_LAST_ENTRY(entry);
266 	    entry = EXT2_EXTATTR_NEXT(entry)) {
267 		if (ext2_extattr_index_to_bsd(entry->e_name_index) != attrnamespace)
268 			continue;
269 
270 		if (strlen(name) == entry->e_name_len &&
271 		    0 == strncmp(entry->e_name, name, entry->e_name_len)) {
272 			if (uio == NULL)
273 				*size += entry->e_value_size;
274 			else {
275 				error = uiomove(((char *)EXT2_IFIRST(header)) +
276 				    entry->e_value_offs, entry->e_value_size, uio);
277 			}
278 
279 			brelse(bp);
280 			return (error);
281 		}
282 	 }
283 
284 	brelse(bp);
285 
286 	return (ENOATTR);
287 }
288 
289 int
290 ext2_extattr_block_get(struct inode *ip, int attrnamespace,
291     const char *name, struct uio *uio, size_t *size)
292 {
293 	struct m_ext2fs *fs;
294 	struct buf *bp;
295 	struct ext2fs_extattr_header *header;
296 	struct ext2fs_extattr_entry *entry;
297 	int error;
298 
299 	fs = ip->i_e2fs;
300 
301 	error = bread(ip->i_devvp, fsbtodb(fs, ip->i_facl),
302 	    fs->e2fs_bsize, NOCRED, &bp);
303 	if (error) {
304 		brelse(bp);
305 		return (error);
306 	}
307 
308 	/* Check attributes magic value */
309 	header = EXT2_HDR(bp);
310 	if (header->h_magic != EXTATTR_MAGIC || header->h_blocks != 1) {
311 		brelse(bp);
312 		return (EINVAL);
313 	}
314 
315 	error = ext2_extattr_check(EXT2_FIRST_ENTRY(bp), bp->b_data + bp->b_bufsize);
316 	if (error) {
317 		brelse(bp);
318 		return (error);
319 	}
320 
321 	for (entry = EXT2_FIRST_ENTRY(bp); !EXT2_IS_LAST_ENTRY(entry);
322 	    entry = EXT2_EXTATTR_NEXT(entry)) {
323 		if (ext2_extattr_index_to_bsd(entry->e_name_index) != attrnamespace)
324 			continue;
325 
326 		if (strlen(name) == entry->e_name_len &&
327 		    0 == strncmp(entry->e_name, name, entry->e_name_len)) {
328 			if (uio == NULL)
329 				*size += entry->e_value_size;
330 			else {
331 				error = uiomove(bp->b_data + entry->e_value_offs,
332 				    entry->e_value_size, uio);
333 			}
334 
335 			brelse(bp);
336 			return (error);
337 		}
338 	 }
339 
340 	brelse(bp);
341 
342 	return (ENOATTR);
343 }
344 
345 static uint16_t
346 ext2_extattr_delete_value(char *off,
347     struct ext2fs_extattr_entry *first_entry,
348     struct ext2fs_extattr_entry *entry, char *end)
349 {
350 	uint16_t min_offs;
351 	struct ext2fs_extattr_entry *next;
352 
353 	min_offs = end - off;
354 	next = first_entry;
355 	while (!EXT2_IS_LAST_ENTRY(next)) {
356 		if (min_offs > next->e_value_offs && next->e_value_offs > 0)
357 			min_offs = next->e_value_offs;
358 
359 		next = EXT2_EXTATTR_NEXT(next);
360 	}
361 
362 	if (entry->e_value_size == 0)
363 		return (min_offs);
364 
365 	memmove(off + min_offs + EXT2_EXTATTR_SIZE(entry->e_value_size),
366 	    off + min_offs, entry->e_value_offs - min_offs);
367 
368 	/* Adjust all value offsets */
369 	next = first_entry;
370 	while (!EXT2_IS_LAST_ENTRY(next))
371 	{
372 		if (next->e_value_offs > 0 &&
373 		    next->e_value_offs < entry->e_value_offs)
374 			next->e_value_offs +=
375 			    EXT2_EXTATTR_SIZE(entry->e_value_size);
376 
377 		next = EXT2_EXTATTR_NEXT(next);
378 	}
379 
380 	min_offs += EXT2_EXTATTR_SIZE(entry->e_value_size);
381 
382 	return (min_offs);
383 }
384 
385 static void
386 ext2_extattr_delete_entry(char *off,
387     struct ext2fs_extattr_entry *first_entry,
388     struct ext2fs_extattr_entry *entry, char *end)
389 {
390 	char *pad;
391 	struct ext2fs_extattr_entry *next;
392 
393 	/* Clean entry value */
394 	ext2_extattr_delete_value(off, first_entry, entry, end);
395 
396 	/* Clean the entry */
397 	next = first_entry;
398 	while (!EXT2_IS_LAST_ENTRY(next))
399 		next = EXT2_EXTATTR_NEXT(next);
400 
401 	pad = (char*)next + sizeof(uint32_t);
402 
403 	memmove(entry, (char *)entry + EXT2_EXTATTR_LEN(entry->e_name_len),
404 	    pad - ((char *)entry + EXT2_EXTATTR_LEN(entry->e_name_len)));
405 }
406 
407 int
408 ext2_extattr_inode_delete(struct inode *ip, int attrnamespace, const char *name)
409 {
410 	struct m_ext2fs *fs;
411 	struct buf *bp;
412 	struct ext2fs_extattr_dinode_header *header;
413 	struct ext2fs_extattr_entry *entry;
414 	int error;
415 
416 	fs = ip->i_e2fs;
417 
418 	if ((error = bread(ip->i_devvp,
419 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
420 	    (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
421 		brelse(bp);
422 		return (error);
423 	}
424 
425 	struct ext2fs_dinode *dinode = (struct ext2fs_dinode *)
426 	    ((char *)bp->b_data +
427 	    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number));
428 
429 	/* Check attributes magic value */
430 	header = (struct ext2fs_extattr_dinode_header *)((char *)dinode +
431 	    E2FS_REV0_INODE_SIZE + dinode->e2di_extra_isize);
432 
433 	if (header->h_magic != EXTATTR_MAGIC) {
434 		brelse(bp);
435 		return (ENOATTR);
436 	}
437 
438 	error = ext2_extattr_check(EXT2_IFIRST(header),
439 	    (char *)dinode + EXT2_INODE_SIZE(fs));
440 	if (error) {
441 		brelse(bp);
442 		return (error);
443 	}
444 
445 	/* If I am last entry, just make magic zero */
446 	entry = EXT2_IFIRST(header);
447 	if (EXT2_IS_LAST_ENTRY(EXT2_EXTATTR_NEXT(entry))) {
448 		if (strlen(name) == entry->e_name_len &&
449 		    0 == strncmp(entry->e_name, name, entry->e_name_len)) {
450 			memset(header, 0, sizeof(struct ext2fs_extattr_dinode_header));
451 
452 			return (bwrite(bp));
453 		}
454 	}
455 
456 	for (entry = EXT2_IFIRST(header); !EXT2_IS_LAST_ENTRY(entry);
457 	    entry = EXT2_EXTATTR_NEXT(entry)) {
458 		if (ext2_extattr_index_to_bsd(entry->e_name_index) != attrnamespace)
459 			continue;
460 
461 		if (strlen(name) == entry->e_name_len &&
462 		    0 == strncmp(entry->e_name, name, entry->e_name_len)) {
463 			ext2_extattr_delete_entry((char *)EXT2_IFIRST(header),
464 			    EXT2_IFIRST(header), entry,
465 			    (char *)dinode + EXT2_INODE_SIZE(fs));
466 
467 			return (bwrite(bp));
468 		}
469 	}
470 
471 	brelse(bp);
472 
473 	return (ENOATTR);
474 }
475 
476 static int
477 ext2_extattr_block_clone(struct inode *ip, struct buf **bpp)
478 {
479 	struct m_ext2fs *fs;
480 	struct buf *sbp;
481 	struct buf *cbp;
482 	struct ext2fs_extattr_header *header;
483 	uint64_t facl;
484 
485 	fs = ip->i_e2fs;
486 	sbp = *bpp;
487 
488 	header = EXT2_HDR(sbp);
489 	if (header->h_magic != EXTATTR_MAGIC || header->h_refcount == 1)
490 		return (EINVAL);
491 
492 	facl = ext2_allocfacl(ip);
493 	if (!facl)
494 		return (ENOSPC);
495 
496 	cbp = getblk(ip->i_devvp, fsbtodb(fs, facl), fs->e2fs_bsize, 0, 0, 0);
497 	if (!cbp) {
498 		ext2_blkfree(ip, facl, fs->e2fs_bsize);
499 		return (EIO);
500 	}
501 
502 	memcpy(cbp->b_data, sbp->b_data, fs->e2fs_bsize);
503 	header->h_refcount--;
504 	bwrite(sbp);
505 
506 	ip->i_facl = facl;
507 	ext2_update(ip->i_vnode, 1);
508 
509 	header = EXT2_HDR(cbp);
510 	header->h_refcount = 1;
511 
512 	*bpp = cbp;
513 
514 	return (0);
515 }
516 
517 int
518 ext2_extattr_block_delete(struct inode *ip, int attrnamespace, const char *name)
519 {
520 	struct m_ext2fs *fs;
521 	struct buf *bp;
522 	struct ext2fs_extattr_header *header;
523 	struct ext2fs_extattr_entry *entry;
524 	int error;
525 
526 	fs = ip->i_e2fs;
527 
528 	error = bread(ip->i_devvp, fsbtodb(fs, ip->i_facl),
529 	    fs->e2fs_bsize, NOCRED, &bp);
530 	if (error) {
531 		brelse(bp);
532 		return (error);
533 	}
534 
535 	/* Check attributes magic value */
536 	header = EXT2_HDR(bp);
537 	if (header->h_magic != EXTATTR_MAGIC || header->h_blocks != 1) {
538 		brelse(bp);
539 		return (EINVAL);
540 	}
541 
542 	error = ext2_extattr_check(EXT2_FIRST_ENTRY(bp), bp->b_data + bp->b_bufsize);
543 	if (error) {
544 		brelse(bp);
545 		return (error);
546 	}
547 
548 	if (header->h_refcount > 1) {
549 		error = ext2_extattr_block_clone(ip, &bp);
550 		if (error) {
551 			brelse(bp);
552 			return (error);
553 		}
554 	}
555 
556 	/* If I am last entry, clean me and free the block */
557 	entry = EXT2_FIRST_ENTRY(bp);
558 	if (EXT2_IS_LAST_ENTRY(EXT2_EXTATTR_NEXT(entry))) {
559 		if (strlen(name) == entry->e_name_len &&
560 		    0 == strncmp(entry->e_name, name, entry->e_name_len)) {
561 			ip->i_blocks -= btodb(fs->e2fs_bsize);
562 			ext2_blkfree(ip, ip->i_facl, fs->e2fs_bsize);
563 			ip->i_facl = 0;
564 			error = ext2_update(ip->i_vnode, 1);
565 
566 			brelse(bp);
567 			return (error);
568 		}
569 	}
570 
571 	for (entry = EXT2_FIRST_ENTRY(bp); !EXT2_IS_LAST_ENTRY(entry);
572 	    entry = EXT2_EXTATTR_NEXT(entry)) {
573 		if (ext2_extattr_index_to_bsd(entry->e_name_index) != attrnamespace)
574 			continue;
575 
576 		if (strlen(name) == entry->e_name_len &&
577 		    0 == strncmp(entry->e_name, name, entry->e_name_len)) {
578 			ext2_extattr_delete_entry(bp->b_data,
579 			    EXT2_FIRST_ENTRY(bp), entry,
580 			    bp->b_data + bp->b_bufsize);
581 
582 			return (bwrite(bp));
583 		}
584 	}
585 
586 	brelse(bp);
587 
588 	return (ENOATTR);
589 }
590 
591 static struct ext2fs_extattr_entry *
592 allocate_entry(const char *name, int attrnamespace, uint16_t offs,
593     uint32_t size, uint32_t hash)
594 {
595 	size_t name_len;
596 	struct ext2fs_extattr_entry *entry;
597 
598 	name_len = strlen(name);
599 	entry = malloc(sizeof(struct ext2fs_extattr_entry) + name_len,
600 	    M_TEMP, M_WAITOK);
601 
602 	entry->e_name_len = name_len;
603 	entry->e_name_index = ext2_extattr_index_to_linux(attrnamespace);
604 	entry->e_value_offs = offs;
605 	entry->e_value_block = 0;
606 	entry->e_value_size = size;
607 	entry->e_hash = hash;
608 	memcpy(entry->e_name, name, name_len);
609 
610 	return (entry);
611 }
612 
613 static void
614 free_entry(struct ext2fs_extattr_entry *entry)
615 {
616 
617 	free(entry, M_TEMP);
618 }
619 
620 static int
621 ext2_extattr_get_size(struct ext2fs_extattr_entry *first_entry,
622     struct ext2fs_extattr_entry *exist_entry, int header_size,
623     int name_len, int new_size)
624 {
625 	struct ext2fs_extattr_entry *entry;
626 	int size;
627 
628 	size = header_size;
629 	size += sizeof(uint32_t);
630 
631 	if (NULL == exist_entry) {
632 		size += EXT2_EXTATTR_LEN(name_len);
633 		size += EXT2_EXTATTR_SIZE(new_size);
634 	}
635 
636 	if (first_entry)
637 		for (entry = first_entry; !EXT2_IS_LAST_ENTRY(entry);
638 		    entry = EXT2_EXTATTR_NEXT(entry)) {
639 			if (entry != exist_entry)
640 				size += EXT2_EXTATTR_LEN(entry->e_name_len) +
641 				    EXT2_EXTATTR_SIZE(entry->e_value_size);
642 			else
643 				size += EXT2_EXTATTR_LEN(entry->e_name_len) +
644 				    EXT2_EXTATTR_SIZE(new_size);
645 		}
646 
647 	return (size);
648 }
649 
650 static void
651 ext2_extattr_set_exist_entry(char *off,
652     struct ext2fs_extattr_entry *first_entry,
653     struct ext2fs_extattr_entry *entry,
654     char *end, struct uio *uio)
655 {
656 	uint16_t min_offs;
657 
658 	min_offs = ext2_extattr_delete_value(off, first_entry, entry, end);
659 
660 	entry->e_value_size = uio->uio_resid;
661 	if (entry->e_value_size)
662 		entry->e_value_offs = min_offs -
663 		    EXT2_EXTATTR_SIZE(uio->uio_resid);
664 	else
665 		entry->e_value_offs = 0;
666 
667 	uiomove(off + entry->e_value_offs, entry->e_value_size, uio);
668 }
669 
670 static struct ext2fs_extattr_entry *
671 ext2_extattr_set_new_entry(char *off, struct ext2fs_extattr_entry *first_entry,
672     const char *name, int attrnamespace, char *end, struct uio *uio)
673 {
674 	int name_len;
675 	char *pad;
676 	uint16_t min_offs;
677 	struct ext2fs_extattr_entry *entry;
678 	struct ext2fs_extattr_entry *new_entry;
679 
680 	/* Find pad's */
681 	min_offs = end - off;
682 	entry = first_entry;
683 	while (!EXT2_IS_LAST_ENTRY(entry)) {
684 		if (min_offs > entry->e_value_offs && entry->e_value_offs > 0)
685 			min_offs = entry->e_value_offs;
686 
687 		entry = EXT2_EXTATTR_NEXT(entry);
688 	}
689 
690 	pad = (char*)entry + sizeof(uint32_t);
691 
692 	/* Find entry insert position */
693 	name_len = strlen(name);
694 	entry = first_entry;
695 	while (!EXT2_IS_LAST_ENTRY(entry)) {
696 		if (!(attrnamespace - entry->e_name_index) &&
697 		    !(name_len - entry->e_name_len))
698 			if (memcmp(name, entry->e_name, name_len) <= 0)
699 				break;
700 
701 		entry = EXT2_EXTATTR_NEXT(entry);
702 	}
703 
704 	/* Create new entry and insert it */
705 	new_entry = allocate_entry(name, attrnamespace, 0, uio->uio_resid, 0);
706 	memmove((char *)entry + EXT2_EXTATTR_LEN(new_entry->e_name_len), entry,
707 	    pad - (char*)entry);
708 
709 	memcpy(entry, new_entry, EXT2_EXTATTR_LEN(new_entry->e_name_len));
710 	free_entry(new_entry);
711 
712 	new_entry = entry;
713 	if (new_entry->e_value_size > 0)
714 		new_entry->e_value_offs = min_offs -
715 		    EXT2_EXTATTR_SIZE(new_entry->e_value_size);
716 
717 	uiomove(off + new_entry->e_value_offs, new_entry->e_value_size, uio);
718 
719 	return (new_entry);
720 }
721 
722 int
723 ext2_extattr_inode_set(struct inode *ip, int attrnamespace,
724     const char *name, struct uio *uio)
725 {
726 	struct m_ext2fs *fs;
727 	struct buf *bp;
728 	struct ext2fs_extattr_dinode_header *header;
729 	struct ext2fs_extattr_entry *entry;
730 	size_t size = 0, max_size;
731 	int error;
732 
733 	fs = ip->i_e2fs;
734 
735 	if ((error = bread(ip->i_devvp,
736 	    fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
737 	    (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
738 		brelse(bp);
739 		return (error);
740 	}
741 
742 	struct ext2fs_dinode *dinode = (struct ext2fs_dinode *)
743 	    ((char *)bp->b_data +
744 	    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number));
745 
746 	/* Check attributes magic value */
747 	header = (struct ext2fs_extattr_dinode_header *)((char *)dinode +
748 	    E2FS_REV0_INODE_SIZE + dinode->e2di_extra_isize);
749 
750 	if (header->h_magic != EXTATTR_MAGIC) {
751 		brelse(bp);
752 		return (ENOSPC);
753 	}
754 
755 	error = ext2_extattr_check(EXT2_IFIRST(header), (char *)dinode +
756 	    EXT2_INODE_SIZE(fs));
757 	if (error) {
758 		brelse(bp);
759 		return (error);
760 	}
761 
762 	/* Find if entry exist */
763 	for (entry = EXT2_IFIRST(header); !EXT2_IS_LAST_ENTRY(entry);
764 	    entry = EXT2_EXTATTR_NEXT(entry)) {
765 		if (ext2_extattr_index_to_bsd(entry->e_name_index) != attrnamespace)
766 			continue;
767 
768 		if (strlen(name) == entry->e_name_len &&
769 		    0 == strncmp(entry->e_name, name, entry->e_name_len))
770 			break;
771 	}
772 
773 	max_size = EXT2_INODE_SIZE(fs) - E2FS_REV0_INODE_SIZE -
774 	    dinode->e2di_extra_isize;
775 
776 	if (!EXT2_IS_LAST_ENTRY(entry)) {
777 		size = ext2_extattr_get_size(EXT2_IFIRST(header), entry,
778 		    sizeof(struct ext2fs_extattr_dinode_header),
779 		    entry->e_name_len, uio->uio_resid);
780 		if (size > max_size) {
781 			brelse(bp);
782 			return (ENOSPC);
783 		}
784 
785 		ext2_extattr_set_exist_entry((char *)EXT2_IFIRST(header),
786 		    EXT2_IFIRST(header), entry, (char *)header + max_size, uio);
787 	} else {
788 		/* Ensure that the same entry does not exist in the block */
789 		if (ip->i_facl) {
790 			error = ext2_extattr_block_get(ip, attrnamespace, name,
791 			    NULL, &size);
792 			if (error != ENOATTR || size > 0) {
793 				brelse(bp);
794 				if (size > 0)
795 					error = ENOSPC;
796 
797 				return (error);
798 			}
799 		}
800 
801 		size = ext2_extattr_get_size(EXT2_IFIRST(header), NULL,
802 		    sizeof(struct ext2fs_extattr_dinode_header),
803 		    entry->e_name_len, uio->uio_resid);
804 		if (size > max_size) {
805 			brelse(bp);
806 			return (ENOSPC);
807 		}
808 
809 		ext2_extattr_set_new_entry((char *)EXT2_IFIRST(header),
810 		    EXT2_IFIRST(header), name, attrnamespace,
811 		    (char *)header + max_size, uio);
812 	}
813 
814 	return (bwrite(bp));
815 }
816 
817 static void
818 ext2_extattr_hash_entry(struct ext2fs_extattr_header *header,
819     struct ext2fs_extattr_entry *entry)
820 {
821 	uint32_t hash = 0;
822 	char *name = entry->e_name;
823 	int n;
824 
825 	for (n=0; n < entry->e_name_len; n++) {
826 		hash = (hash << EXT2_EXTATTR_NAME_HASH_SHIFT) ^
827 		    (hash >> (8*sizeof(hash) - EXT2_EXTATTR_NAME_HASH_SHIFT)) ^
828 		    (*name++);
829 	}
830 
831 	if (entry->e_value_block == 0 && entry->e_value_size != 0) {
832 		uint32_t *value = (uint32_t *)((char *)header + entry->e_value_offs);
833 		for (n = (entry->e_value_size +
834 		    EXT2_EXTATTR_ROUND) >> EXT2_EXTATTR_PAD_BITS; n; n--) {
835 			hash = (hash << EXT2_EXTATTR_VALUE_HASH_SHIFT) ^
836 			    (hash >> (8*sizeof(hash) - EXT2_EXTATTR_VALUE_HASH_SHIFT)) ^
837 			    (*value++);
838 		}
839 	}
840 
841 	entry->e_hash = hash;
842 }
843 
844 static void
845 ext2_extattr_rehash(struct ext2fs_extattr_header *header,
846     struct ext2fs_extattr_entry *entry)
847 {
848 	struct ext2fs_extattr_entry *here;
849 	uint32_t hash = 0;
850 
851 	ext2_extattr_hash_entry(header, entry);
852 
853 	here = EXT2_ENTRY(header+1);
854 	while (!EXT2_IS_LAST_ENTRY(here)) {
855 		if (!here->e_hash) {
856 			/* Block is not shared if an entry's hash value == 0 */
857 			hash = 0;
858 			break;
859 		}
860 
861 		hash = (hash << EXT2_EXTATTR_BLOCK_HASH_SHIFT) ^
862 		    (hash >> (8*sizeof(hash) - EXT2_EXTATTR_BLOCK_HASH_SHIFT)) ^
863 		    here->e_hash;
864 
865 		here = EXT2_EXTATTR_NEXT(here);
866 	}
867 
868 	header->h_hash = hash;
869 }
870 
871 int
872 ext2_extattr_block_set(struct inode *ip, int attrnamespace,
873     const char *name, struct uio *uio)
874 {
875 	struct m_ext2fs *fs;
876 	struct buf *bp;
877 	struct ext2fs_extattr_header *header;
878 	struct ext2fs_extattr_entry *entry;
879 	size_t size;
880 	int error;
881 
882 	fs = ip->i_e2fs;
883 
884 	if (ip->i_facl) {
885 		error = bread(ip->i_devvp, fsbtodb(fs, ip->i_facl),
886 		    fs->e2fs_bsize, NOCRED, &bp);
887 		if (error) {
888 			brelse(bp);
889 			return (error);
890 		}
891 
892 		/* Check attributes magic value */
893 		header = EXT2_HDR(bp);
894 		if (header->h_magic != EXTATTR_MAGIC || header->h_blocks != 1) {
895 			brelse(bp);
896 			return (EINVAL);
897 		}
898 
899 		error = ext2_extattr_check(EXT2_FIRST_ENTRY(bp),
900 		    bp->b_data + bp->b_bufsize);
901 		if (error) {
902 			brelse(bp);
903 			return (error);
904 		}
905 
906 		if (header->h_refcount > 1) {
907 			error = ext2_extattr_block_clone(ip, &bp);
908 			if (error) {
909 				brelse(bp);
910 				return (error);
911 			}
912 
913 			header = EXT2_HDR(bp);
914 		}
915 
916 		/* Find if entry exist */
917 		for (entry = EXT2_FIRST_ENTRY(bp); !EXT2_IS_LAST_ENTRY(entry);
918 		    entry = EXT2_EXTATTR_NEXT(entry)) {
919 			if (ext2_extattr_index_to_bsd(entry->e_name_index) != attrnamespace)
920 				continue;
921 
922 			if (strlen(name) == entry->e_name_len &&
923 			    0 == strncmp(entry->e_name, name, entry->e_name_len))
924 				break;
925 		}
926 
927 		if (!EXT2_IS_LAST_ENTRY(entry)) {
928 			size = ext2_extattr_get_size(EXT2_FIRST_ENTRY(bp), entry,
929 			    sizeof(struct ext2fs_extattr_header),
930 			    entry->e_name_len, uio->uio_resid);
931 			if (size > bp->b_bufsize) {
932 				brelse(bp);
933 				return (ENOSPC);
934 			}
935 
936 			ext2_extattr_set_exist_entry(bp->b_data, EXT2_FIRST_ENTRY(bp),
937 			    entry, bp->b_data + bp->b_bufsize, uio);
938 		} else {
939 			size = ext2_extattr_get_size(EXT2_FIRST_ENTRY(bp), NULL,
940 			    sizeof(struct ext2fs_extattr_header),
941 			    strlen(name), uio->uio_resid);
942 			if (size > bp->b_bufsize) {
943 				brelse(bp);
944 				return (ENOSPC);
945 			}
946 
947 			entry = ext2_extattr_set_new_entry(bp->b_data, EXT2_FIRST_ENTRY(bp),
948 			    name, attrnamespace, bp->b_data + bp->b_bufsize, uio);
949 
950 			/* Clean the same entry in the inode */
951 			error = ext2_extattr_inode_delete(ip, attrnamespace, name);
952 			if (error && error != ENOATTR) {
953 				brelse(bp);
954 				return (error);
955 			}
956 		}
957 
958 		ext2_extattr_rehash(header, entry);
959 
960 		return (bwrite(bp));
961 	}
962 
963 	size = ext2_extattr_get_size(NULL, NULL,
964 	    sizeof(struct ext2fs_extattr_header), strlen(name), uio->uio_resid);
965 	if (size > fs->e2fs_bsize)
966 		return (ENOSPC);
967 
968 	/* Allocate block, fill EA header and insert entry */
969 	ip->i_facl = ext2_allocfacl(ip);
970 	if (0 == ip->i_facl)
971 		return (ENOSPC);
972 
973 	ip->i_blocks += btodb(fs->e2fs_bsize);
974 	ext2_update(ip->i_vnode, 1);
975 
976 	bp = getblk(ip->i_devvp, fsbtodb(fs, ip->i_facl), fs->e2fs_bsize, 0, 0, 0);
977 	if (!bp) {
978 		ext2_blkfree(ip, ip->i_facl, fs->e2fs_bsize);
979 		ip->i_blocks -= btodb(fs->e2fs_bsize);
980 		ip->i_facl = 0;
981 		ext2_update(ip->i_vnode, 1);
982 		return (EIO);
983 	}
984 
985 	header = EXT2_HDR(bp);
986 	header->h_magic = EXTATTR_MAGIC;
987 	header->h_refcount = 1;
988 	header->h_blocks = 1;
989 	header->h_hash = 0;
990 	memset(header->h_reserved, 0, sizeof(header->h_reserved));
991 	memcpy(bp->b_data, header, sizeof(struct ext2fs_extattr_header));
992 	memset(EXT2_FIRST_ENTRY(bp), 0, sizeof(uint32_t));
993 
994 	entry = ext2_extattr_set_new_entry(bp->b_data, EXT2_FIRST_ENTRY(bp),
995 	    name, attrnamespace, bp->b_data + bp->b_bufsize, uio);
996 
997 	/* Clean the same entry in the inode */
998 	error = ext2_extattr_inode_delete(ip, attrnamespace, name);
999 	if (error && error != ENOATTR) {
1000 		brelse(bp);
1001 		return (error);
1002 	}
1003 
1004 	ext2_extattr_rehash(header, entry);
1005 
1006 	return (bwrite(bp));
1007 }
1008 
1009 int ext2_extattr_free(struct inode *ip)
1010 {
1011 	struct m_ext2fs *fs;
1012 	struct buf *bp;
1013 	struct ext2fs_extattr_header *header;
1014 	int error;
1015 
1016 	fs = ip->i_e2fs;
1017 
1018 	if (!ip->i_facl)
1019 		return (0);
1020 
1021 	error = bread(ip->i_devvp, fsbtodb(fs, ip->i_facl),
1022 	    fs->e2fs_bsize, NOCRED, &bp);
1023 	if (error) {
1024 		brelse(bp);
1025 		return (error);
1026 	}
1027 
1028 	/* Check attributes magic value */
1029 	header = EXT2_HDR(bp);
1030 	if (header->h_magic != EXTATTR_MAGIC || header->h_blocks != 1) {
1031 		brelse(bp);
1032 		return (EINVAL);
1033 	}
1034 
1035 	error = ext2_extattr_check(EXT2_FIRST_ENTRY(bp), bp->b_data + bp->b_bufsize);
1036 	if (error) {
1037 		brelse(bp);
1038 		return (error);
1039 	}
1040 
1041 	if (header->h_refcount > 1) {
1042 		header->h_refcount--;
1043 		bwrite(bp);
1044 	} else {
1045 		ext2_blkfree(ip, ip->i_facl, ip->i_e2fs->e2fs_bsize);
1046 		brelse(bp);
1047 	}
1048 
1049 	ip->i_blocks -= btodb(ip->i_e2fs->e2fs_bsize);
1050 	ip->i_facl = 0;
1051 	ext2_update(ip->i_vnode, 1);
1052 
1053 	return (0);
1054 }
1055