xref: /freebsd/sys/fs/ext2fs/ext2_htree.c (revision 2e5b60079b7d8c3ca68f1390cd90f305e651f8d3)
1 /*-
2  * Copyright (c) 2010, 2012 Zheng Liu <lz@freebsd.org>
3  * Copyright (c) 2012, Vyacheslav Matyushin
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include <sys/param.h>
31 #include <sys/endian.h>
32 #include <sys/systm.h>
33 #include <sys/namei.h>
34 #include <sys/bio.h>
35 #include <sys/buf.h>
36 #include <sys/endian.h>
37 #include <sys/mount.h>
38 #include <sys/vnode.h>
39 #include <sys/malloc.h>
40 #include <sys/dirent.h>
41 #include <sys/sysctl.h>
42 
43 #include <ufs/ufs/dir.h>
44 
45 #include <fs/ext2fs/inode.h>
46 #include <fs/ext2fs/ext2_mount.h>
47 #include <fs/ext2fs/ext2fs.h>
48 #include <fs/ext2fs/fs.h>
49 #include <fs/ext2fs/ext2_extern.h>
50 #include <fs/ext2fs/ext2_dinode.h>
51 #include <fs/ext2fs/ext2_dir.h>
52 #include <fs/ext2fs/htree.h>
53 
54 static void	ext2_append_entry(char *block, uint32_t blksize,
55 		    struct ext2fs_direct_2 *last_entry,
56 		    struct ext2fs_direct_2 *new_entry);
57 static int	ext2_htree_append_block(struct vnode *vp, char *data,
58 		    struct componentname *cnp, uint32_t blksize);
59 static int	ext2_htree_check_next(struct inode *ip, uint32_t hash,
60 		    const char *name, struct ext2fs_htree_lookup_info *info);
61 static int	ext2_htree_cmp_sort_entry(const void *e1, const void *e2);
62 static int	ext2_htree_find_leaf(struct inode *ip, const char *name,
63 		    int namelen, uint32_t *hash, uint8_t *hash_version,
64 		    struct ext2fs_htree_lookup_info *info);
65 static uint32_t ext2_htree_get_block(struct ext2fs_htree_entry *ep);
66 static uint16_t	ext2_htree_get_count(struct ext2fs_htree_entry *ep);
67 static uint32_t ext2_htree_get_hash(struct ext2fs_htree_entry *ep);
68 static uint16_t	ext2_htree_get_limit(struct ext2fs_htree_entry *ep);
69 static void	ext2_htree_insert_entry_to_level(struct ext2fs_htree_lookup_level *level,
70 		    uint32_t hash, uint32_t blk);
71 static void	ext2_htree_insert_entry(struct ext2fs_htree_lookup_info *info,
72 		    uint32_t hash, uint32_t blk);
73 static uint32_t	ext2_htree_node_limit(struct inode *ip);
74 static void	ext2_htree_set_block(struct ext2fs_htree_entry *ep,
75 		    uint32_t blk);
76 static void	ext2_htree_set_count(struct ext2fs_htree_entry *ep,
77 		    uint16_t cnt);
78 static void	ext2_htree_set_hash(struct ext2fs_htree_entry *ep,
79 		    uint32_t hash);
80 static void	ext2_htree_set_limit(struct ext2fs_htree_entry *ep,
81 		    uint16_t limit);
82 static int	ext2_htree_split_dirblock(char *block1, char *block2,
83 		    uint32_t blksize, uint32_t *hash_seed, uint8_t hash_version,
84 		    uint32_t *split_hash, struct  ext2fs_direct_2 *entry);
85 static void	ext2_htree_release(struct ext2fs_htree_lookup_info *info);
86 static uint32_t	ext2_htree_root_limit(struct inode *ip, int len);
87 static int	ext2_htree_writebuf(struct ext2fs_htree_lookup_info *info);
88 
89 int
90 ext2_htree_has_idx(struct inode *ip)
91 {
92 	if (EXT2_HAS_COMPAT_FEATURE(ip->i_e2fs, EXT2F_COMPAT_DIRHASHINDEX) &&
93 	    ip->i_flag & IN_E4INDEX)
94 		return (1);
95 	else
96 		return (0);
97 }
98 
99 static int
100 ext2_htree_check_next(struct inode *ip, uint32_t hash, const char *name,
101 		struct ext2fs_htree_lookup_info *info)
102 {
103 	struct vnode *vp = ITOV(ip);
104 	struct ext2fs_htree_lookup_level *level;
105 	struct buf *bp;
106 	uint32_t next_hash;
107 	int idx = info->h_levels_num - 1;
108 	int levels = 0;
109 
110 	do {
111 		level = &info->h_levels[idx];
112 		level->h_entry++;
113 		if (level->h_entry < level->h_entries +
114 		    ext2_htree_get_count(level->h_entries))
115 			break;
116 		if (idx == 0)
117 			return (0);
118 		idx--;
119 		levels++;
120 	} while (1);
121 
122 	next_hash = ext2_htree_get_hash(level->h_entry);
123 	if ((hash & 1) == 0) {
124 		if (hash != (next_hash & ~1))
125 			return (0);
126 	}
127 
128 	while (levels > 0) {
129 		levels--;
130 		if (ext2_blkatoff(vp, ext2_htree_get_block(level->h_entry) *
131 		    ip->i_e2fs->e2fs_bsize, NULL, &bp) != 0)
132 			return (0);
133 		level = &info->h_levels[idx + 1];
134 		brelse(level->h_bp);
135 		level->h_bp = bp;
136 		level->h_entry = level->h_entries =
137 		    ((struct ext2fs_htree_node *)bp->b_data)->h_entries;
138 	}
139 
140 	return (1);
141 }
142 
143 static uint32_t
144 ext2_htree_get_block(struct ext2fs_htree_entry *ep)
145 {
146 	return (ep->h_blk & 0x00FFFFFF);
147 }
148 
149 static void
150 ext2_htree_set_block(struct ext2fs_htree_entry *ep, uint32_t blk)
151 {
152 	ep->h_blk = blk;
153 }
154 
155 static uint16_t
156 ext2_htree_get_count(struct ext2fs_htree_entry *ep)
157 {
158 	return (((struct ext2fs_htree_count *)(ep))->h_entries_num);
159 }
160 
161 static void
162 ext2_htree_set_count(struct ext2fs_htree_entry *ep, uint16_t cnt)
163 {
164 	((struct ext2fs_htree_count *)(ep))->h_entries_num = cnt;
165 }
166 
167 static uint32_t
168 ext2_htree_get_hash(struct ext2fs_htree_entry *ep)
169 {
170 	return (ep->h_hash);
171 }
172 
173 static uint16_t
174 ext2_htree_get_limit(struct ext2fs_htree_entry *ep)
175 {
176 	return (((struct ext2fs_htree_count *)(ep))->h_entries_max);
177 }
178 
179 static void
180 ext2_htree_set_hash(struct ext2fs_htree_entry *ep, uint32_t hash)
181 {
182 	ep->h_hash = hash;
183 }
184 
185 static void
186 ext2_htree_set_limit(struct ext2fs_htree_entry *ep, uint16_t limit)
187 {
188 	((struct ext2fs_htree_count *)(ep))->h_entries_max = limit;
189 }
190 
191 static void
192 ext2_htree_release(struct ext2fs_htree_lookup_info *info)
193 {
194 	int i;
195 
196 	for (i = 0; i < info->h_levels_num; i++) {
197 		struct buf *bp = info->h_levels[i].h_bp;
198 		if (bp != NULL)
199 			brelse(bp);
200 	}
201 }
202 
203 static uint32_t
204 ext2_htree_root_limit(struct inode *ip, int len)
205 {
206 	uint32_t space;
207 
208 	space = ip->i_e2fs->e2fs_bsize - EXT2_DIR_REC_LEN(1) -
209 	    EXT2_DIR_REC_LEN(2) - len;
210 	return (space / sizeof(struct ext2fs_htree_entry));
211 }
212 
213 static uint32_t
214 ext2_htree_node_limit(struct inode *ip)
215 {
216 	struct m_ext2fs *fs;
217 	uint32_t space;
218 
219 	fs = ip->i_e2fs;
220 	space = fs->e2fs_bsize - EXT2_DIR_REC_LEN(0);
221 
222 	return (space / sizeof(struct ext2fs_htree_entry));
223 }
224 
225 static int
226 ext2_htree_find_leaf(struct inode *ip, const char *name, int namelen,
227 		     uint32_t *hash, uint8_t *hash_ver,
228 		     struct ext2fs_htree_lookup_info *info)
229 {
230 	struct vnode *vp;
231 	struct ext2fs *fs;
232 	struct m_ext2fs *m_fs;
233 	struct buf *bp = NULL;
234 	struct ext2fs_htree_root *rootp;
235 	struct ext2fs_htree_entry *entp, *start, *end, *middle, *found;
236 	struct ext2fs_htree_lookup_level *level_info;
237 	uint32_t hash_major = 0, hash_minor = 0;
238 	uint32_t levels, cnt;
239 	uint8_t hash_version;
240 
241 	if (name == NULL || info == NULL)
242 		return (-1);
243 
244 	vp = ITOV(ip);
245 	fs = ip->i_e2fs->e2fs;
246 	m_fs = ip->i_e2fs;
247 
248 	if (ext2_blkatoff(vp, 0, NULL, &bp) != 0)
249 		return (-1);
250 
251 	info->h_levels_num = 1;
252 	info->h_levels[0].h_bp = bp;
253 	rootp = (struct ext2fs_htree_root *)bp->b_data;
254 	if (rootp->h_info.h_hash_version != EXT2_HTREE_LEGACY &&
255 	    rootp->h_info.h_hash_version != EXT2_HTREE_HALF_MD4 &&
256 	    rootp->h_info.h_hash_version != EXT2_HTREE_TEA)
257 		goto error;
258 
259 	hash_version = rootp->h_info.h_hash_version;
260 	if (hash_version <= EXT2_HTREE_TEA)
261 		hash_version += m_fs->e2fs_uhash;
262 	*hash_ver = hash_version;
263 
264 	ext2_htree_hash(name, namelen, fs->e3fs_hash_seed,
265 	    hash_version, &hash_major, &hash_minor);
266 	*hash = hash_major;
267 
268 	if ((levels = rootp->h_info.h_ind_levels) > 1)
269 		goto error;
270 
271 	entp = (struct ext2fs_htree_entry *)(((char *)&rootp->h_info) +
272 	    rootp->h_info.h_info_len);
273 
274 	if (ext2_htree_get_limit(entp) !=
275 	    ext2_htree_root_limit(ip, rootp->h_info.h_info_len))
276 		goto error;
277 
278 	while (1) {
279 		cnt = ext2_htree_get_count(entp);
280 		if (cnt == 0 || cnt > ext2_htree_get_limit(entp))
281 			goto error;
282 
283 		start = entp + 1;
284 		end = entp + cnt - 1;
285 		while (start <= end) {
286 			middle = start + (end - start) / 2;
287 			if (ext2_htree_get_hash(middle) > hash_major)
288 				end = middle - 1;
289 			else
290 				start = middle + 1;
291 		}
292 		found = start - 1;
293 
294 		level_info = &(info->h_levels[info->h_levels_num - 1]);
295 		level_info->h_bp = bp;
296 		level_info->h_entries = entp;
297 		level_info->h_entry = found;
298 		if (levels == 0)
299 			return (0);
300 		levels--;
301 		if (ext2_blkatoff(vp,
302 		    ext2_htree_get_block(found) * m_fs->e2fs_bsize,
303 		    NULL, &bp) != 0)
304 			goto error;
305 		entp = ((struct ext2fs_htree_node *)bp->b_data)->h_entries;
306 		info->h_levels_num++;
307 		info->h_levels[info->h_levels_num - 1].h_bp = bp;
308 	}
309 
310 error:
311 	ext2_htree_release(info);
312 	return (-1);
313 }
314 
315 /*
316  * Try to lookup a directory entry in HTree index
317  */
318 int
319 ext2_htree_lookup(struct inode *ip, const char *name, int namelen,
320 		  struct buf **bpp, int *entryoffp, doff_t *offp,
321 		  doff_t *prevoffp, doff_t *endusefulp,
322 		  struct ext2fs_searchslot *ss)
323 {
324 	struct vnode *vp;
325 	struct ext2fs_htree_lookup_info info;
326 	struct ext2fs_htree_entry *leaf_node;
327 	struct m_ext2fs *m_fs;
328 	struct buf *bp;
329 	uint32_t blk;
330 	uint32_t dirhash;
331 	uint32_t bsize;
332 	uint8_t hash_version;
333 	int search_next;
334 	int found = 0;
335 
336 	m_fs = ip->i_e2fs;
337 	bsize = m_fs->e2fs_bsize;
338 	vp = ITOV(ip);
339 
340 	/* TODO: print error msg because we don't lookup '.' and '..' */
341 
342 	memset(&info, 0, sizeof(info));
343 	if (ext2_htree_find_leaf(ip, name, namelen, &dirhash,
344 	    &hash_version, &info))
345 		return (-1);
346 
347 	do {
348 		leaf_node = info.h_levels[info.h_levels_num - 1].h_entry;
349 		blk = ext2_htree_get_block(leaf_node);
350 		if (ext2_blkatoff(vp, blk * bsize, NULL, &bp) != 0) {
351 			ext2_htree_release(&info);
352 			return (-1);
353 		}
354 
355 		*offp = blk * bsize;
356 		*entryoffp = 0;
357 		*prevoffp = blk * bsize;
358 		*endusefulp = blk * bsize;
359 
360 		if (ss->slotstatus == NONE) {
361 			ss->slotoffset = -1;
362 			ss->slotfreespace = 0;
363 		}
364 
365 		if (ext2_search_dirblock(ip, bp->b_data, &found,
366 		    name, namelen, entryoffp, offp, prevoffp,
367 		    endusefulp, ss) != 0) {
368 			brelse(bp);
369 			ext2_htree_release(&info);
370 			return (-1);
371 		}
372 
373 		if (found) {
374 			*bpp = bp;
375 			ext2_htree_release(&info);
376 			return (0);
377 		}
378 
379 		brelse(bp);
380 		search_next = ext2_htree_check_next(ip, dirhash, name, &info);
381 	} while (search_next);
382 
383 	ext2_htree_release(&info);
384 	return (ENOENT);
385 }
386 
387 static int
388 ext2_htree_append_block(struct vnode *vp, char *data,
389 			struct componentname *cnp, uint32_t blksize)
390 {
391 	struct iovec aiov;
392 	struct uio auio;
393 	struct inode *dp = VTOI(vp);
394 	uint64_t cursize, newsize;
395 	int error;
396 
397 	cursize = roundup(dp->i_size, blksize);
398 	newsize = cursize + blksize;
399 
400 	auio.uio_offset = cursize;
401 	auio.uio_resid = blksize;
402 	aiov.iov_len = blksize;
403 	aiov.iov_base = data;
404 	auio.uio_iov = &aiov;
405 	auio.uio_iovcnt = 1;
406 	auio.uio_rw = UIO_WRITE;
407 	auio.uio_segflg = UIO_SYSSPACE;
408 	error = VOP_WRITE(vp, &auio, IO_SYNC, cnp->cn_cred);
409 	if (!error)
410 		dp->i_size = newsize;
411 
412 	return (error);
413 }
414 
415 static int
416 ext2_htree_writebuf(struct ext2fs_htree_lookup_info *info)
417 {
418 	int i, error;
419 
420 	for (i = 0; i < info->h_levels_num; i++) {
421 		struct buf *bp = info->h_levels[i].h_bp;
422 		error = bwrite(bp);
423 		if (error)
424 			return (error);
425 	}
426 
427 	return (0);
428 }
429 
430 static void
431 ext2_htree_insert_entry_to_level(struct ext2fs_htree_lookup_level *level,
432 				 uint32_t hash, uint32_t blk)
433 {
434 	struct ext2fs_htree_entry *target;
435 	int entries_num;
436 
437 	target = level->h_entry + 1;
438 	entries_num = ext2_htree_get_count(level->h_entries);
439 
440 	memmove(target + 1, target, (char *)(level->h_entries + entries_num) -
441 	    (char *)target);
442 	ext2_htree_set_block(target, blk);
443 	ext2_htree_set_hash(target, hash);
444 	ext2_htree_set_count(level->h_entries, entries_num + 1);
445 }
446 
447 /*
448  * Insert an index entry to the index node.
449  */
450 static void
451 ext2_htree_insert_entry(struct ext2fs_htree_lookup_info *info,
452 			uint32_t hash, uint32_t blk)
453 {
454 	struct ext2fs_htree_lookup_level *level;
455 
456 	level = &info->h_levels[info->h_levels_num - 1];
457 	ext2_htree_insert_entry_to_level(level, hash, blk);
458 }
459 
460 /*
461  * Compare two entry sort descriptors by name hash value.
462  * This is used together with qsort.
463  */
464 static int
465 ext2_htree_cmp_sort_entry(const void *e1, const void *e2)
466 {
467 	const struct ext2fs_htree_sort_entry *entry1, *entry2;
468 
469 	entry1 = (const struct ext2fs_htree_sort_entry *)e1;
470 	entry2 = (const struct ext2fs_htree_sort_entry *)e2;
471 
472 	if (entry1->h_hash < entry2->h_hash)
473 		return (-1);
474 	if (entry1->h_hash > entry2->h_hash)
475 		return (1);
476 	return (0);
477 }
478 
479 /*
480  * Append an entry to the end of the directory block.
481  */
482 static void
483 ext2_append_entry(char *block, uint32_t blksize,
484 		  struct ext2fs_direct_2 *last_entry,
485 		  struct ext2fs_direct_2 *new_entry)
486 {
487 	uint16_t entry_len;
488 
489 	entry_len = EXT2_DIR_REC_LEN(last_entry->e2d_namlen);
490 	last_entry->e2d_reclen = entry_len;
491 	last_entry = (struct ext2fs_direct_2 *)((char *)last_entry + entry_len);
492 	new_entry->e2d_reclen = block + blksize - (char *)last_entry;
493 	memcpy(last_entry, new_entry, EXT2_DIR_REC_LEN(new_entry->e2d_namlen));
494 }
495 
496 /*
497  * Move half of entries from the old directory block to the new one.
498  */
499 static int
500 ext2_htree_split_dirblock(char *block1, char *block2, uint32_t blksize,
501 			  uint32_t *hash_seed, uint8_t hash_version,
502 			  uint32_t *split_hash, struct ext2fs_direct_2 *entry)
503 {
504 	int entry_cnt = 0;
505 	int size = 0;
506 	int i, k;
507 	uint32_t offset;
508 	uint16_t entry_len = 0;
509 	uint32_t entry_hash;
510 	struct ext2fs_direct_2 *ep, *last;
511 	char *dest;
512 	struct ext2fs_htree_sort_entry *sort_info;
513 
514 	ep = (struct ext2fs_direct_2 *)block1;
515 	dest = block2;
516 	sort_info = (struct ext2fs_htree_sort_entry *)
517 	    ((char *)block2 + blksize);
518 
519 	/*
520 	 * Calculate name hash value for the entry which is to be added.
521 	 */
522 	ext2_htree_hash(entry->e2d_name, entry->e2d_namlen, hash_seed,
523 	    hash_version, &entry_hash, NULL);
524 
525 	/*
526 	 * Fill in directory entry sort descriptors.
527 	 */
528 	while ((char *)ep < block1 + blksize) {
529 		if (ep->e2d_ino && ep->e2d_namlen) {
530 			entry_cnt++;
531 			sort_info--;
532 			sort_info->h_size = ep->e2d_reclen;
533 			sort_info->h_offset = (char *)ep - block1;
534 			ext2_htree_hash(ep->e2d_name, ep->e2d_namlen,
535 			    hash_seed, hash_version,
536 			    &sort_info->h_hash, NULL);
537 		}
538 		ep = (struct ext2fs_direct_2 *)
539 		    ((char *)ep + ep->e2d_reclen);
540 	}
541 
542 	/*
543 	 * Sort directory entry descriptors by name hash value.
544 	 */
545 	qsort(sort_info, entry_cnt, sizeof(struct ext2fs_htree_sort_entry),
546 	    ext2_htree_cmp_sort_entry);
547 
548 	/*
549 	 * Count the number of entries to move to directory block 2.
550 	 */
551 	for (i = entry_cnt - 1; i >= 0; i--) {
552 		if (sort_info[i].h_size + size > blksize / 2)
553 			break;
554 		size += sort_info[i].h_size;
555 	}
556 
557 	*split_hash = sort_info[i + 1].h_hash;
558 
559 	/*
560 	 * Set collision bit.
561 	 */
562 	if (*split_hash == sort_info[i].h_hash)
563 		*split_hash += 1;
564 
565 	/*
566 	 * Move half of directory entries from block 1 to block 2.
567 	 */
568 	for (k = i + 1; k < entry_cnt; k++) {
569 		ep = (struct ext2fs_direct_2 *)((char *)block1 +
570 		    sort_info[k].h_offset);
571 		entry_len = EXT2_DIR_REC_LEN(ep->e2d_namlen);
572 		memcpy(dest, ep, entry_len);
573 		((struct ext2fs_direct_2 *)dest)->e2d_reclen = entry_len;
574 		/* Mark directory entry as unused. */
575 		ep->e2d_ino = 0;
576 		dest += entry_len;
577 	}
578 	dest -= entry_len;
579 
580 	/* Shrink directory entries in block 1. */
581 	last = (struct ext2fs_direct_2 *)block1;
582 	entry_len = EXT2_DIR_REC_LEN(last->e2d_namlen);
583 	for (offset = last->e2d_reclen; offset < blksize; ) {
584 		ep = (struct ext2fs_direct_2 *)(block1 + offset);
585 		offset += ep->e2d_reclen;
586 		if (last->e2d_ino) {
587 			/* Trim the existing slot */
588 			last->e2d_reclen = entry_len;
589 			last = (struct ext2fs_direct_2 *)
590 			   ((char *)last + entry_len);
591 		}
592 		entry_len = EXT2_DIR_REC_LEN(ep->e2d_namlen);
593 		memcpy((void *)last, (void *)ep, entry_len);
594 	}
595 
596 	if (entry_hash >= *split_hash) {
597 		/* Add entry to block 2. */
598 		ext2_append_entry(block2, blksize,
599 		    (struct ext2fs_direct_2 *)dest, entry);
600 
601 		/* Adjust length field of last entry of block 1. */
602 		last->e2d_reclen = block1 + blksize - (char *)last;
603 	} else {
604 		/* Add entry to block 1. */
605 		ext2_append_entry(block1, blksize, last, entry);
606 
607 		/* Adjust length field of last entry of block 2. */
608 		((struct ext2fs_direct_2 *)dest)->e2d_reclen =
609 		    block2 + blksize - dest;
610 	}
611 
612 	return (0);
613 }
614 
615 /*
616  * Create an HTree index for a directory
617  */
618 int
619 ext2_htree_create_index(struct vnode *vp, struct componentname *cnp,
620 			struct ext2fs_direct_2 *new_entry)
621 {
622 	struct buf *bp = NULL;
623 	struct inode *dp;
624 	struct ext2fs *fs;
625 	struct m_ext2fs *m_fs;
626 	struct ext2fs_direct_2 *ep, *dotdot;
627 	struct ext2fs_htree_root *root;
628 	struct ext2fs_htree_lookup_info info;
629 	uint32_t blksize, dirlen, split_hash;
630 	uint8_t hash_version;
631 	char *buf1 = NULL;
632 	char *buf2 = NULL;
633 	int error = 0;
634 
635 	dp = VTOI(vp);
636 	fs = dp->i_e2fs->e2fs;
637 	m_fs = dp->i_e2fs;
638 	blksize = m_fs->e2fs_bsize;
639 
640 	buf1 = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
641 	buf2 = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
642 
643 	if ((error = ext2_blkatoff(vp, 0, NULL, &bp)) != 0)
644 		goto out;
645 
646 	root = (struct ext2fs_htree_root *)bp->b_data;
647 	dotdot = (struct ext2fs_direct_2 *)((char *)&(root->h_dotdot));
648 	ep = (struct ext2fs_direct_2 *)((char *)dotdot + dotdot->e2d_reclen);
649 	dirlen = (char *)root + blksize - (char *)ep;
650 	memcpy(buf1, ep, dirlen);
651 	ep = (struct ext2fs_direct_2 *)buf1;
652 	while ((char *)ep < buf1 + dirlen)
653 		ep = (struct ext2fs_direct_2 *)
654 		    ((char *)ep + ep->e2d_reclen);
655 	ep->e2d_reclen = buf1 + blksize - (char *)ep;
656 
657 	dp->i_flag |= IN_E4INDEX;
658 
659 	/*
660 	 * Initialize index root.
661 	 */
662 	dotdot->e2d_reclen = blksize - EXT2_DIR_REC_LEN(1);
663 	memset(&root->h_info, 0, sizeof(root->h_info));
664 	root->h_info.h_hash_version = fs->e3fs_def_hash_version;
665 	root->h_info.h_info_len = sizeof(root->h_info);
666 	ext2_htree_set_block(root->h_entries, 1);
667 	ext2_htree_set_count(root->h_entries, 1);
668 	ext2_htree_set_limit(root->h_entries,
669 	    ext2_htree_root_limit(dp, sizeof(root->h_info)));
670 
671 	memset(&info, 0, sizeof(info));
672 	info.h_levels_num = 1;
673 	info.h_levels[0].h_entries = root->h_entries;
674 	info.h_levels[0].h_entry = root->h_entries;
675 
676 	hash_version = root->h_info.h_hash_version;
677 	if (hash_version <= EXT2_HTREE_TEA)
678 		hash_version += m_fs->e2fs_uhash;
679 	ext2_htree_split_dirblock(buf1, buf2, blksize, fs->e3fs_hash_seed,
680 	    hash_version, &split_hash, new_entry);
681 	ext2_htree_insert_entry(&info, split_hash, 2);
682 
683 	/*
684 	 * Write directory block 0.
685 	 */
686 	if (DOINGASYNC(vp)) {
687 		bdwrite(bp);
688 		error = 0;
689 	} else {
690 		error = bwrite(bp);
691 	}
692 	dp->i_flag |= IN_CHANGE | IN_UPDATE;
693 	if (error)
694 		goto out;
695 
696 	/*
697 	 * Write directory block 1.
698 	 */
699 	error = ext2_htree_append_block(vp, buf1, cnp, blksize);
700 	if (error)
701 		goto out1;
702 
703 	/*
704 	 * Write directory block 2.
705 	 */
706 	error = ext2_htree_append_block(vp, buf2, cnp, blksize);
707 
708 	free(buf1, M_TEMP);
709 	free(buf2, M_TEMP);
710 	return (error);
711 out:
712 	if (bp != NULL)
713 		brelse(bp);
714 out1:
715 	free(buf1, M_TEMP);
716 	free(buf2, M_TEMP);
717 	return (error);
718 }
719 
720 /*
721  * Add an entry to the directory using htree index.
722  */
723 int
724 ext2_htree_add_entry(struct vnode *dvp, struct ext2fs_direct_2 *entry,
725 		     struct componentname *cnp)
726 {
727 	struct ext2fs_htree_entry *entries, *leaf_node;
728 	struct ext2fs_htree_lookup_info info;
729 	struct buf *bp = NULL;
730 	struct ext2fs *fs;
731 	struct m_ext2fs *m_fs;
732 	struct inode *ip;
733 	uint16_t ent_num;
734 	uint32_t dirhash, split_hash;
735 	uint32_t blksize, blknum;
736 	uint64_t cursize, dirsize;
737 	uint8_t hash_version;
738 	char *newdirblock = NULL;
739 	char *newidxblock = NULL;
740 	struct ext2fs_htree_node *dst_node;
741 	struct ext2fs_htree_entry *dst_entries;
742 	struct ext2fs_htree_entry *root_entires;
743 	struct buf *dst_bp = NULL;
744 	int error, write_bp = 0, write_dst_bp = 0, write_info = 0;
745 
746 	ip = VTOI(dvp);
747 	m_fs = ip->i_e2fs;
748 	fs = m_fs->e2fs;
749 	blksize = m_fs->e2fs_bsize;
750 
751 	if (ip->i_count != 0)
752 		return ext2_add_entry(dvp, entry);
753 
754 	/* Target directory block is full, split it */
755 	memset(&info, 0, sizeof(info));
756 	error = ext2_htree_find_leaf(ip, entry->e2d_name, entry->e2d_namlen,
757 	    &dirhash, &hash_version, &info);
758 	if (error)
759 		return (error);
760 
761 	entries = info.h_levels[info.h_levels_num - 1].h_entries;
762 	ent_num = ext2_htree_get_count(entries);
763 	if (ent_num == ext2_htree_get_limit(entries)) {
764 		/* Split the index node. */
765 		root_entires = info.h_levels[0].h_entries;
766 		newidxblock = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
767 		dst_node = (struct ext2fs_htree_node *)newidxblock;
768 		dst_entries = dst_node->h_entries;
769 		memset(&dst_node->h_fake_dirent, 0,
770 		    sizeof(dst_node->h_fake_dirent));
771 		dst_node->h_fake_dirent.e2d_reclen = blksize;
772 
773 		cursize = roundup(ip->i_size, blksize);
774 		dirsize = cursize + blksize;
775 		blknum = dirsize / blksize - 1;
776 
777 		error = ext2_htree_append_block(dvp, newidxblock,
778 		    cnp, blksize);
779 		if (error)
780 			goto finish;
781 		error = ext2_blkatoff(dvp, cursize, NULL, &dst_bp);
782 		if (error)
783 			goto finish;
784 		dst_node = (struct ext2fs_htree_node *)dst_bp->b_data;
785 		dst_entries = dst_node->h_entries;
786 
787 		if (info.h_levels_num == 2) {
788 			uint16_t src_ent_num, dst_ent_num;
789 
790 			if (ext2_htree_get_count(root_entires) ==
791 			    ext2_htree_get_limit(root_entires)) {
792 				/* Directory index is full */
793 				error = EIO;
794 				goto finish;
795 			}
796 
797 			src_ent_num = ent_num / 2;
798 			dst_ent_num = ent_num - src_ent_num;
799 			split_hash = ext2_htree_get_hash(entries + src_ent_num);
800 
801 			/* Move half of index entries to the new index node */
802 			memcpy(dst_entries, entries + src_ent_num,
803 			    dst_ent_num * sizeof(struct ext2fs_htree_entry));
804 			ext2_htree_set_count(entries, src_ent_num);
805 			ext2_htree_set_count(dst_entries, dst_ent_num);
806 			ext2_htree_set_limit(dst_entries,
807 			    ext2_htree_node_limit(ip));
808 
809 			if (info.h_levels[1].h_entry >= entries + src_ent_num) {
810 				struct buf *tmp = info.h_levels[1].h_bp;
811 				info.h_levels[1].h_bp = dst_bp;
812 				dst_bp = tmp;
813 
814 				info.h_levels[1].h_entry =
815 				    info.h_levels[1].h_entry -
816 				    (entries + src_ent_num) +
817 				    dst_entries;
818 				info.h_levels[1].h_entries = dst_entries;
819 			}
820 			ext2_htree_insert_entry_to_level(&info.h_levels[0],
821 			    split_hash, blknum);
822 
823 			/* Write new index node to disk */
824 			error = bwrite(dst_bp);
825 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
826 			if (error)
827 				goto finish;
828 			write_dst_bp = 1;
829 		} else {
830 			/* Create second level for htree index */
831 			struct ext2fs_htree_root *idx_root;
832 
833 			memcpy(dst_entries, entries,
834 			    ent_num * sizeof(struct ext2fs_htree_entry));
835 			ext2_htree_set_limit(dst_entries,
836 			    ext2_htree_node_limit(ip));
837 
838 			idx_root = (struct ext2fs_htree_root *)
839 			    info.h_levels[0].h_bp->b_data;
840 			idx_root->h_info.h_ind_levels = 1;
841 
842 			ext2_htree_set_count(entries, 1);
843 			ext2_htree_set_block(entries, blknum);
844 
845 			info.h_levels_num = 2;
846 			info.h_levels[1].h_entries = dst_entries;
847 			info.h_levels[1].h_entry = info.h_levels[0].h_entry -
848 			    info.h_levels[0].h_entries + dst_entries;
849 			info.h_levels[1].h_bp = dst_bp;
850 		}
851 	}
852 
853 	leaf_node = info.h_levels[info.h_levels_num - 1].h_entry;
854 	blknum = ext2_htree_get_block(leaf_node);
855 	error = ext2_blkatoff(dvp, blknum * blksize, NULL, &bp);
856 	if (error)
857 		goto finish;
858 
859 	/* Split target directory block */
860 	newdirblock = malloc(blksize, M_TEMP, M_WAITOK | M_ZERO);
861 	ext2_htree_split_dirblock((char *)bp->b_data, newdirblock, blksize,
862 	    fs->e3fs_hash_seed, hash_version, &split_hash, entry);
863 	cursize = roundup(ip->i_size, blksize);
864 	dirsize = roundup(ip->i_size, blksize) + blksize;
865 	blknum = dirsize / blksize - 1;
866 
867 	/* Add index entry for the new directory block */
868 	ext2_htree_insert_entry(&info, split_hash, blknum);
869 
870 	/* Write the new directory block to the end of the directory */
871 	error = ext2_htree_append_block(dvp, newdirblock, cnp, blksize);
872 	if (error)
873 		goto finish;
874 
875 	/* Write the target directory block */
876 	error = bwrite(bp);
877 	ip->i_flag |= IN_CHANGE | IN_UPDATE;
878 	if (error)
879 		goto finish;
880 	write_bp = 1;
881 
882 	/* Write the index block */
883 	error = ext2_htree_writebuf(&info);
884 	if (!error)
885 		write_info = 1;
886 
887 finish:
888 	if (dst_bp != NULL && !write_dst_bp)
889 		brelse(dst_bp);
890 	if (bp != NULL && !write_bp)
891 		brelse(bp);
892 	if (newdirblock != NULL)
893 		free(newdirblock, M_TEMP);
894 	if (newidxblock != NULL)
895 		free(newidxblock, M_TEMP);
896 	if (!write_info)
897 		ext2_htree_release(&info);
898 	return (error);
899 }
900