xref: /aosp_15_r20/external/e2fsprogs/lib/ext2fs/link.c (revision 6a54128f25917bfc36a8a6e9d722c04a0b4641b6)
1 /*
2  * link.c --- create links in a ext2fs directory
3  *
4  * Copyright (C) 1993, 1994 Theodore Ts'o.
5  *
6  * %Begin-Header%
7  * This file may be redistributed under the terms of the GNU Library
8  * General Public License, version 2.
9  * %End-Header%
10  */
11 
12 #include "config.h"
13 #include <stdio.h>
14 #include <string.h>
15 #if HAVE_UNISTD_H
16 #include <unistd.h>
17 #endif
18 
19 #include "ext2_fs.h"
20 #include "ext2fs.h"
21 #include "ext2fsP.h"
22 
23 #define EXT2_DX_ROOT_OFF 24
24 
25 struct dx_frame {
26 	void *buf;
27 	blk64_t pblock;
28 	struct ext2_dx_countlimit *head;
29 	struct ext2_dx_entry *entries;
30 	struct ext2_dx_entry *at;
31 };
32 
33 struct dx_lookup_info {
34 	const char *name;
35 	int namelen;
36 	int hash_alg;
37 	__u32 hash;
38 	unsigned levels;
39 	struct dx_frame frames[EXT4_HTREE_LEVEL];
40 };
41 
alloc_dx_frame(ext2_filsys fs,struct dx_frame * frame)42 static errcode_t alloc_dx_frame(ext2_filsys fs, struct dx_frame *frame)
43 {
44 	return ext2fs_get_mem(fs->blocksize, &frame->buf);
45 }
46 
dx_release(struct dx_lookup_info * info)47 static void dx_release(struct dx_lookup_info *info)
48 {
49 	unsigned level;
50 
51 	for (level = 0; level < info->levels; level++) {
52 		if (info->frames[level].buf == NULL)
53 			break;
54 		ext2fs_free_mem(&(info->frames[level].buf));
55 	}
56 	info->levels = 0;
57 }
58 
dx_search_entry(struct dx_frame * frame,int count,__u32 hash)59 static void dx_search_entry(struct dx_frame *frame, int count, __u32 hash)
60 {
61 	struct ext2_dx_entry *p, *q, *m;
62 
63 	p = frame->entries + 1;
64 	q = frame->entries + count - 1;
65 	while (p <= q) {
66 		m = p + (q - p) / 2;
67 		if (ext2fs_le32_to_cpu(m->hash) > hash)
68 			q = m - 1;
69 		else
70 			p = m + 1;
71 	}
72 	frame->at = p - 1;
73 }
74 
load_logical_dir_block(ext2_filsys fs,ext2_ino_t dir,struct ext2_inode * diri,blk64_t block,blk64_t * pblk,void * buf)75 static errcode_t load_logical_dir_block(ext2_filsys fs, ext2_ino_t dir,
76 					struct ext2_inode *diri, blk64_t block,
77 					blk64_t *pblk, void *buf)
78 {
79 	errcode_t errcode;
80 	int ret_flags;
81 
82 	errcode = ext2fs_bmap2(fs, dir, diri, NULL, 0, block, &ret_flags,
83 			       pblk);
84 	if (errcode)
85 		return errcode;
86 	if (ret_flags & BMAP_RET_UNINIT)
87 		return EXT2_ET_DIR_CORRUPTED;
88 	return ext2fs_read_dir_block4(fs, *pblk, buf, 0, dir);
89 }
90 
dx_lookup(ext2_filsys fs,ext2_ino_t dir,struct ext2_inode * diri,struct dx_lookup_info * info)91 static errcode_t dx_lookup(ext2_filsys fs, ext2_ino_t dir,
92 			   struct ext2_inode *diri, struct dx_lookup_info *info)
93 {
94 	struct ext2_dx_root_info *root;
95 	errcode_t errcode;
96 	int level = 0;
97 	int count, limit;
98 	int hash_alg;
99 	int hash_flags = diri->i_flags & EXT4_CASEFOLD_FL;
100 	__u32 minor_hash;
101 	struct dx_frame *frame;
102 
103 	errcode = alloc_dx_frame(fs, &(info->frames[0]));
104 	if (errcode)
105 		return errcode;
106 	info->levels = 1;
107 
108 	errcode = load_logical_dir_block(fs, dir, diri, 0,
109 					 &(info->frames[0].pblock),
110 					 info->frames[0].buf);
111 	if (errcode)
112 		goto out_err;
113 	root = (struct ext2_dx_root_info *) ((char *)info->frames[0].buf +
114 					     EXT2_DX_ROOT_OFF);
115 	hash_alg = root->hash_version;
116 	if (hash_alg != EXT2_HASH_TEA && hash_alg != EXT2_HASH_HALF_MD4 &&
117 	    hash_alg != EXT2_HASH_LEGACY) {
118 		errcode = EXT2_ET_DIRHASH_UNSUPP;
119 		goto out_err;
120 	}
121 	if (hash_alg <= EXT2_HASH_TEA &&
122 	    fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH)
123 		hash_alg += 3;
124 	if (root->indirect_levels >= ext2_dir_htree_level(fs)) {
125 		errcode = EXT2_ET_DIR_CORRUPTED;
126 		goto out_err;
127 	}
128 	info->hash_alg = hash_alg;
129 
130 	errcode = ext2fs_dirhash2(hash_alg, info->name, info->namelen,
131 				  fs->encoding, hash_flags,
132 				  fs->super->s_hash_seed, &info->hash,
133 				  &minor_hash);
134 	if (errcode)
135 		goto out_err;
136 
137 	for (level = 0; level <= root->indirect_levels; level++) {
138 		frame = &(info->frames[level]);
139 		if (level > 0) {
140 			errcode = alloc_dx_frame(fs, frame);
141 			if (errcode)
142 				goto out_err;
143 			info->levels++;
144 
145 			errcode = load_logical_dir_block(fs, dir, diri,
146 				ext2fs_le32_to_cpu(info->frames[level-1].at->block) & 0x0fffffff,
147 				&(frame->pblock), frame->buf);
148 			if (errcode)
149 				goto out_err;
150 		}
151 		errcode = ext2fs_get_dx_countlimit(fs, frame->buf,
152 						   &(frame->head), NULL);
153 		if (errcode)
154 			goto out_err;
155 		count = ext2fs_le16_to_cpu(frame->head->count);
156 		limit = ext2fs_le16_to_cpu(frame->head->limit);
157 		frame->entries = (struct ext2_dx_entry *)(frame->head);
158 		if (!count || count > limit) {
159 			errcode = EXT2_ET_DIR_CORRUPTED;
160 			goto out_err;
161 		}
162 
163 		dx_search_entry(frame, count, info->hash);
164 	}
165 	return 0;
166 out_err:
167 	dx_release(info);
168 	return errcode;
169 }
170 
171 struct link_struct  {
172 	ext2_filsys	fs;
173 	const char	*name;
174 	int		namelen;
175 	ext2_ino_t	inode;
176 	int		flags;
177 	int		done;
178 	unsigned int	blocksize;
179 	errcode_t	err;
180 	struct ext2_super_block *sb;
181 };
182 
link_proc(ext2_ino_t dir EXT2FS_ATTR ((unused)),int entru EXT2FS_ATTR ((unused)),struct ext2_dir_entry * dirent,int offset,int blocksize,char * buf,void * priv_data)183 static int link_proc(ext2_ino_t dir EXT2FS_ATTR((unused)),
184 		     int entru EXT2FS_ATTR((unused)),
185 		     struct ext2_dir_entry *dirent,
186 		     int	offset,
187 		     int	blocksize,
188 		     char	*buf,
189 		     void	*priv_data)
190 {
191 	struct link_struct *ls = (struct link_struct *) priv_data;
192 	struct ext2_dir_entry *next;
193 	unsigned int rec_len, min_rec_len, curr_rec_len;
194 	int ret = 0;
195 	int csum_size = 0;
196 
197 	if (ls->done)
198 		return DIRENT_ABORT;
199 
200 	rec_len = EXT2_DIR_REC_LEN(ls->namelen);
201 
202 	ls->err = ext2fs_get_rec_len(ls->fs, dirent, &curr_rec_len);
203 	if (ls->err)
204 		return DIRENT_ABORT;
205 
206 	if (ext2fs_has_feature_metadata_csum(ls->fs->super))
207 		csum_size = sizeof(struct ext2_dir_entry_tail);
208 	/*
209 	 * See if the following directory entry (if any) is unused;
210 	 * if so, absorb it into this one.
211 	 */
212 	next = (struct ext2_dir_entry *) (buf + offset + curr_rec_len);
213 	if ((offset + (int) curr_rec_len < blocksize - (8 + csum_size)) &&
214 	    (next->inode == 0) &&
215 	    (offset + (int) curr_rec_len + (int) next->rec_len <= blocksize)) {
216 		curr_rec_len += next->rec_len;
217 		ls->err = ext2fs_set_rec_len(ls->fs, curr_rec_len, dirent);
218 		if (ls->err)
219 			return DIRENT_ABORT;
220 		ret = DIRENT_CHANGED;
221 	}
222 
223 	/*
224 	 * If the directory entry is used, see if we can split the
225 	 * directory entry to make room for the new name.  If so,
226 	 * truncate it and return.
227 	 */
228 	if (dirent->inode) {
229 		min_rec_len = EXT2_DIR_REC_LEN(ext2fs_dirent_name_len(dirent));
230 		if (curr_rec_len < (min_rec_len + rec_len))
231 			return ret;
232 		rec_len = curr_rec_len - min_rec_len;
233 		ls->err = ext2fs_set_rec_len(ls->fs, min_rec_len, dirent);
234 		if (ls->err)
235 			return DIRENT_ABORT;
236 		next = (struct ext2_dir_entry *) (buf + offset +
237 						  dirent->rec_len);
238 		next->inode = 0;
239 		ext2fs_dirent_set_name_len(next, 0);
240 		ext2fs_dirent_set_file_type(next, 0);
241 		ls->err = ext2fs_set_rec_len(ls->fs, rec_len, next);
242 		if (ls->err)
243 			return DIRENT_ABORT;
244 		return DIRENT_CHANGED;
245 	}
246 
247 	/*
248 	 * If we get this far, then the directory entry is not used.
249 	 * See if we can fit the request entry in.  If so, do it.
250 	 */
251 	if (curr_rec_len < rec_len)
252 		return ret;
253 	dirent->inode = ls->inode;
254 	ext2fs_dirent_set_name_len(dirent, ls->namelen);
255 	strncpy(dirent->name, ls->name, ls->namelen);
256 	if (ext2fs_has_feature_filetype(ls->sb))
257 		ext2fs_dirent_set_file_type(dirent, ls->flags & 0x7);
258 
259 	ls->done++;
260 	return DIRENT_ABORT|DIRENT_CHANGED;
261 }
262 
add_dirent_to_buf(ext2_filsys fs,e2_blkcnt_t blockcnt,char * buf,ext2_ino_t dir,struct ext2_inode * diri,const char * name,ext2_ino_t ino,int flags,blk64_t * pblkp)263 static errcode_t add_dirent_to_buf(ext2_filsys fs, e2_blkcnt_t blockcnt,
264 				   char *buf, ext2_ino_t dir,
265 				   struct ext2_inode *diri, const char *name,
266 				   ext2_ino_t ino, int flags, blk64_t *pblkp)
267 {
268 	struct dir_context ctx;
269 	struct link_struct ls;
270 	errcode_t retval;
271 
272 	retval = load_logical_dir_block(fs, dir, diri, blockcnt, pblkp, buf);
273 	if (retval)
274 		return retval;
275 	ctx.errcode = 0;
276 	ctx.func = link_proc;
277 	ctx.dir = dir;
278 	ctx.flags = DIRENT_FLAG_INCLUDE_EMPTY;
279 	ctx.buf = buf;
280 	ctx.priv_data = &ls;
281 
282 	ls.fs = fs;
283 	ls.name = name;
284 	ls.namelen = strlen(name);
285 	ls.inode = ino;
286 	ls.flags = flags;
287 	ls.done = 0;
288 	ls.sb = fs->super;
289 	ls.blocksize = fs->blocksize;
290 	ls.err = 0;
291 
292 	ext2fs_process_dir_block(fs, pblkp, blockcnt, 0, 0, &ctx);
293 	if (ctx.errcode)
294 		return ctx.errcode;
295 	if (ls.err)
296 		return ls.err;
297 	if (!ls.done)
298 		return EXT2_ET_DIR_NO_SPACE;
299 	return 0;
300 }
301 
302 struct dx_hash_map {
303 	__u32 hash;
304 	int size;
305 	int off;
306 };
307 
dx_hash_map_cmp(const void * ap,const void * bp)308 static EXT2_QSORT_TYPE dx_hash_map_cmp(const void *ap, const void *bp)
309 {
310 	const struct dx_hash_map *a = ap, *b = bp;
311 
312 	if (a->hash < b->hash)
313 		return -1;
314 	if (a->hash > b->hash)
315 		return 1;
316 	return 0;
317 }
318 
dx_move_dirents(ext2_filsys fs,struct dx_hash_map * map,int count,void * from,void * to)319 static errcode_t dx_move_dirents(ext2_filsys fs, struct dx_hash_map *map,
320 				 int count, void *from, void *to)
321 {
322 	struct ext2_dir_entry *de;
323 	int i;
324 	int rec_len = 0;
325 	errcode_t retval;
326 	int csum_size = 0;
327 	void *base = to;
328 
329 	if (ext2fs_has_feature_metadata_csum(fs->super))
330 		csum_size = sizeof(struct ext2_dir_entry_tail);
331 
332 	for (i = 0; i < count; i++) {
333 		de = (struct ext2_dir_entry *) ((char *)from + map[i].off);
334 		rec_len = EXT2_DIR_REC_LEN(ext2fs_dirent_name_len(de));
335 		memcpy(to, de, rec_len);
336 		retval = ext2fs_set_rec_len(fs, rec_len, to);
337 		if (retval)
338 			return retval;
339 		to = (char *)to + rec_len;
340 	}
341 	/*
342 	 * Update rec_len of the last dir entry to stretch to the end of block
343 	 */
344 	to = (char *)to - rec_len;
345 	rec_len = fs->blocksize - ((char *)to - (char *)base) - csum_size;
346 	retval = ext2fs_set_rec_len(fs, rec_len, to);
347 	if (retval)
348 		return retval;
349 	if (csum_size)
350 		ext2fs_initialize_dirent_tail(fs,
351 				EXT2_DIRENT_TAIL(base, fs->blocksize));
352 	return 0;
353 }
354 
dx_insert_entry(ext2_filsys fs,ext2_ino_t dir,struct dx_lookup_info * info,int level,__u32 hash,blk64_t lblk)355 static errcode_t dx_insert_entry(ext2_filsys fs, ext2_ino_t dir,
356 				 struct dx_lookup_info *info, int level,
357 				 __u32 hash, blk64_t lblk)
358 {
359 	int pcount;
360 	struct ext2_dx_entry *top, *new;
361 
362 	pcount = ext2fs_le16_to_cpu(info->frames[level].head->count);
363 	top = info->frames[level].entries + pcount;
364 	new = info->frames[level].at + 1;
365 	memmove(new + 1, new, (char *)top - (char *)new);
366 	new->hash = ext2fs_cpu_to_le32(hash);
367 	new->block = ext2fs_cpu_to_le32(lblk);
368 	info->frames[level].head->count = ext2fs_cpu_to_le16(pcount + 1);
369 	return ext2fs_write_dir_block4(fs, info->frames[level].pblock,
370 				       info->frames[level].buf, 0, dir);
371 }
372 
dx_split_leaf(ext2_filsys fs,ext2_ino_t dir,struct ext2_inode * diri,struct dx_lookup_info * info,void * buf,blk64_t leaf_pblk,blk64_t new_lblk,blk64_t new_pblk)373 static errcode_t dx_split_leaf(ext2_filsys fs, ext2_ino_t dir,
374 			       struct ext2_inode *diri,
375 			       struct dx_lookup_info *info, void *buf,
376 			       blk64_t leaf_pblk, blk64_t new_lblk,
377 			       blk64_t new_pblk)
378 {
379 	int hash_flags = diri->i_flags & EXT4_CASEFOLD_FL;
380 	struct ext2_dir_entry *de;
381 	void *buf2;
382 	errcode_t retval = 0;
383 	unsigned int rec_len;
384 	unsigned int offset, move_size;
385 	int i, count = 0;
386 	struct dx_hash_map *map;
387 	int continued;
388 	__u32 minor_hash;
389 
390 	retval = ext2fs_get_mem(fs->blocksize, &buf2);
391 	if (retval)
392 		return retval;
393 	retval = ext2fs_get_array(fs->blocksize / 12,
394 				  sizeof(struct dx_hash_map), &map);
395 	if (retval) {
396 		ext2fs_free_mem(&buf2);
397 		return retval;
398 	}
399 	for (offset = 0; offset < fs->blocksize; offset += rec_len) {
400 		de = (struct ext2_dir_entry *) ((char *)buf + offset);
401 		retval = ext2fs_get_rec_len(fs, de, &rec_len);
402 		if (retval)
403 			goto out;
404 		if (ext2fs_dirent_name_len(de) > 0 && de->inode) {
405 			map[count].off = offset;
406 			map[count].size = rec_len;
407 			retval = ext2fs_dirhash2(info->hash_alg, de->name,
408 					ext2fs_dirent_name_len(de),
409 					fs->encoding, hash_flags,
410 					fs->super->s_hash_seed,
411 					&(map[count].hash),
412 					&minor_hash);
413 			if (retval)
414 				goto out;
415 			count++;
416 		}
417 	}
418 	qsort(map, count, sizeof(struct dx_hash_map), dx_hash_map_cmp);
419 	move_size = 0;
420 	/* Find place to split block */
421 	for (i = count - 1; i >= 0; i--) {
422 		if (move_size + map[i].size / 2 > fs->blocksize / 2)
423 			break;
424 		move_size += map[i].size;
425 	}
426 	/* Let i be the first entry to move */
427 	i++;
428 	/* Move selected directory entries to new block */
429 	retval = dx_move_dirents(fs, map + i, count - i, buf, buf2);
430 	if (retval)
431 		goto out;
432 	retval = ext2fs_write_dir_block4(fs, new_pblk, buf2, 0, dir);
433 	if (retval)
434 		goto out;
435 	/* Repack remaining entries in the old block */
436 	retval = dx_move_dirents(fs, map, i, buf, buf2);
437 	if (retval)
438 		goto out;
439 	retval = ext2fs_write_dir_block4(fs, leaf_pblk, buf2, 0, dir);
440 	if (retval)
441 		goto out;
442 	/* Update parent node */
443 	continued = map[i].hash == map[i-1].hash;
444 	retval = dx_insert_entry(fs, dir, info, info->levels - 1,
445 				 map[i].hash + continued, new_lblk);
446 out:
447 	ext2fs_free_mem(&buf2);
448 	ext2fs_free_mem(&map);
449 	return retval;
450 }
451 
dx_grow_tree(ext2_filsys fs,ext2_ino_t dir,struct ext2_inode * diri,struct dx_lookup_info * info,void * buf,blk64_t leaf_pblk)452 static errcode_t dx_grow_tree(ext2_filsys fs, ext2_ino_t dir,
453 			      struct ext2_inode *diri,
454 			      struct dx_lookup_info *info, void *buf,
455 			      blk64_t leaf_pblk)
456 {
457 	int i;
458 	errcode_t retval;
459 	ext2_off64_t size = EXT2_I_SIZE(diri);
460 	blk64_t lblk, pblk;
461 	struct ext2_dir_entry *de;
462 	struct ext2_dx_countlimit *head;
463 	int csum_size = 0;
464 	int count;
465 
466 	if (ext2fs_has_feature_metadata_csum(fs->super))
467 		csum_size = sizeof(struct ext2_dx_tail);
468 
469 	/* Find level which can accommodate new child */
470 	for (i = info->levels - 1; i >= 0; i--)
471 		if (ext2fs_le16_to_cpu(info->frames[i].head->count) <
472 		    ext2fs_le16_to_cpu(info->frames[i].head->limit))
473 			break;
474 	/* Need to grow tree depth? */
475 	if (i < 0 && info->levels >= ext2_dir_htree_level(fs))
476 		return EXT2_ET_DIR_NO_SPACE;
477 	lblk = size / fs->blocksize;
478 	size += fs->blocksize;
479 	retval = ext2fs_inode_size_set(fs, diri, size);
480 	if (retval)
481 		return retval;
482 	retval = ext2fs_fallocate(fs,
483 			EXT2_FALLOCATE_FORCE_INIT | EXT2_FALLOCATE_ZERO_BLOCKS,
484 			dir, diri, 0, lblk, 1);
485 	if (retval)
486 		return retval;
487 	retval = ext2fs_write_inode(fs, dir, diri);
488 	if (retval)
489 		return retval;
490 	retval = ext2fs_bmap2(fs, dir, diri, NULL, 0, lblk, NULL, &pblk);
491 	if (retval)
492 		return retval;
493 	/* Only leaf addition needed? */
494 	if (i == (int)info->levels - 1)
495 		return dx_split_leaf(fs, dir, diri, info, buf, leaf_pblk,
496 				     lblk, pblk);
497 
498 	de = buf;
499 	de->inode = 0;
500 	ext2fs_dirent_set_name_len(de, 0);
501 	ext2fs_dirent_set_file_type(de, 0);
502 	retval = ext2fs_set_rec_len(fs, fs->blocksize, de);
503 	if (retval)
504 		return retval;
505 	head = (struct ext2_dx_countlimit *) ((char *)buf + 8);
506 	count = ext2fs_le16_to_cpu(info->frames[i+1].head->count);
507 	/* Growing tree depth? */
508 	if (i < 0) {
509 		struct ext2_dx_root_info *root;
510 
511 		memcpy(head, info->frames[0].entries,
512 		       count * sizeof(struct ext2_dx_entry));
513 		head->limit = ext2fs_cpu_to_le16(
514 				(fs->blocksize - (8 + csum_size)) /
515 				sizeof(struct ext2_dx_entry));
516 		/* head->count gets set by memcpy above to correct value */
517 
518 		/* Now update tree root */
519 		info->frames[0].head->count = ext2fs_cpu_to_le16(1);
520 		info->frames[0].entries[0].block = ext2fs_cpu_to_le32(lblk);
521 		root = (struct ext2_dx_root_info *)
522 			((char *)info->frames[0].buf + EXT2_DX_ROOT_OFF);
523 		root->indirect_levels++;
524 	} else {
525 		/* Splitting internal node in two */
526 		int count1 = count / 2;
527 		int count2 = count - count1;
528 		__u32 split_hash = ext2fs_le32_to_cpu(info->frames[i+1].entries[count1].hash);
529 
530 		memcpy(head, info->frames[i+1].entries + count1,
531 		       count2 * sizeof(struct ext2_dx_entry));
532 		head->count = ext2fs_cpu_to_le16(count2);
533 		head->limit = ext2fs_cpu_to_le16(
534 				(fs->blocksize - (8 + csum_size)) /
535 				sizeof(struct ext2_dx_entry));
536 		info->frames[i+1].head->count = ext2fs_cpu_to_le16(count1);
537 
538 		/* Update parent node */
539 		retval = dx_insert_entry(fs, dir, info, i, split_hash, lblk);
540 		if (retval)
541 			return retval;
542 
543 	}
544 	/* Writeout split block / updated root */
545 	retval = ext2fs_write_dir_block4(fs, info->frames[i+1].pblock,
546 					 info->frames[i+1].buf, 0, dir);
547 	if (retval)
548 		return retval;
549 	/* Writeout new tree block */
550 	retval = ext2fs_write_dir_block4(fs, pblk, buf, 0, dir);
551 	if (retval)
552 		return retval;
553 	return 0;
554 }
555 
dx_link(ext2_filsys fs,ext2_ino_t dir,struct ext2_inode * diri,const char * name,ext2_ino_t ino,int flags)556 static errcode_t dx_link(ext2_filsys fs, ext2_ino_t dir,
557 			 struct ext2_inode *diri, const char *name,
558 			 ext2_ino_t ino, int flags)
559 {
560 	struct dx_lookup_info dx_info;
561 	errcode_t retval;
562 	void *blockbuf;
563 	unsigned restart = 0;
564 	blk64_t leaf_pblk;
565 
566 	retval = ext2fs_get_mem(fs->blocksize, &blockbuf);
567 	if (retval)
568 		return retval;
569 
570 	dx_info.name = name;
571 	dx_info.namelen = strlen(name);
572 again:
573 	retval = dx_lookup(fs, dir, diri, &dx_info);
574 	if (retval)
575 		goto free_buf;
576 
577 	retval = add_dirent_to_buf(fs,
578 		ext2fs_le32_to_cpu(dx_info.frames[dx_info.levels-1].at->block) & 0x0fffffff,
579 		blockbuf, dir, diri, name, ino, flags, &leaf_pblk);
580 	/*
581 	 * Success or error other than ENOSPC...? We are done. We may need upto
582 	 * two tries to add entry. One to split htree node and another to add
583 	 * new leaf block.
584 	 */
585 	if (restart >= dx_info.levels || retval != EXT2_ET_DIR_NO_SPACE)
586 		goto free_frames;
587 	retval = dx_grow_tree(fs, dir, diri, &dx_info, blockbuf, leaf_pblk);
588 	if (retval)
589 		goto free_frames;
590 	/* Restart everything now that the tree is larger */
591 	restart++;
592 	dx_release(&dx_info);
593 	goto again;
594 free_frames:
595 	dx_release(&dx_info);
596 free_buf:
597 	ext2fs_free_mem(&blockbuf);
598 	return retval;
599 }
600 
601 /*
602  * Note: the low 3 bits of the flags field are used as the directory
603  * entry filetype.
604  */
605 #ifdef __TURBOC__
606  #pragma argsused
607 #endif
ext2fs_link(ext2_filsys fs,ext2_ino_t dir,const char * name,ext2_ino_t ino,int flags)608 errcode_t ext2fs_link(ext2_filsys fs, ext2_ino_t dir, const char *name,
609 		      ext2_ino_t ino, int flags)
610 {
611 	errcode_t		retval;
612 	struct link_struct	ls;
613 	struct ext2_inode	inode;
614 
615 	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
616 
617 	if (!(fs->flags & EXT2_FLAG_RW))
618 		return EXT2_ET_RO_FILSYS;
619 
620 	if ((retval = ext2fs_read_inode(fs, dir, &inode)) != 0)
621 		return retval;
622 
623 	if (inode.i_flags & EXT2_INDEX_FL)
624 		return dx_link(fs, dir, &inode, name, ino, flags);
625 
626 	ls.fs = fs;
627 	ls.name = name;
628 	ls.namelen = name ? strlen(name) : 0;
629 	ls.inode = ino;
630 	ls.flags = flags;
631 	ls.done = 0;
632 	ls.sb = fs->super;
633 	ls.blocksize = fs->blocksize;
634 	ls.err = 0;
635 
636 	retval = ext2fs_dir_iterate2(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY,
637 				     NULL, link_proc, &ls);
638 	if (retval)
639 		return retval;
640 	if (ls.err)
641 		return ls.err;
642 
643 	if (!ls.done)
644 		return EXT2_ET_DIR_NO_SPACE;
645 	return 0;
646 }
647