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1 /*
2  * rehash.c --- rebuild hash tree directories
3  *
4  * Copyright (C) 2002 Theodore Ts'o
5  *
6  * %Begin-Header%
7  * This file may be redistributed under the terms of the GNU Public
8  * License.
9  * %End-Header%
10  *
11  * This algorithm is designed for simplicity of implementation and to
12  * pack the directory as much as possible.  It however requires twice
13  * as much memory as the size of the directory.  The maximum size
14  * directory supported using a 4k blocksize is roughly a gigabyte, and
15  * so there may very well be problems with machines that don't have
16  * virtual memory, and obscenely large directories.
17  *
18  * An alternate algorithm which is much more disk intensive could be
19  * written, and probably will need to be written in the future.  The
20  * design goals of such an algorithm are: (a) use (roughly) constant
21  * amounts of memory, no matter how large the directory, (b) the
22  * directory must be safe at all times, even if e2fsck is interrupted
23  * in the middle, (c) we must use minimal amounts of extra disk
24  * blocks.  This pretty much requires an incremental approach, where
25  * we are reading from one part of the directory, and inserting into
26  * the front half.  So the algorithm will have to keep track of a
27  * moving block boundary between the new tree and the old tree, and
28  * files will need to be moved from the old directory and inserted
29  * into the new tree.  If the new directory requires space which isn't
30  * yet available, blocks from the beginning part of the old directory
31  * may need to be moved to the end of the directory to make room for
32  * the new tree:
33  *
34  *    --------------------------------------------------------
35  *    |  new tree   |        | old tree                      |
36  *    --------------------------------------------------------
37  *                  ^ ptr    ^ptr
38  *                tail new   head old
39  *
40  * This is going to be a pain in the tuckus to implement, and will
41  * require a lot more disk accesses.  So I'm going to skip it for now;
42  * it's only really going to be an issue for really, really big
43  * filesystems (when we reach the level of tens of millions of files
44  * in a single directory).  It will probably be easier to simply
45  * require that e2fsck use VM first.
46  */
47 
48 #include "config.h"
49 #include <string.h>
50 #include <ctype.h>
51 #include <errno.h>
52 #include "e2fsck.h"
53 #include "problem.h"
54 
55 /* Schedule a dir to be rebuilt during pass 3A. */
e2fsck_rehash_dir_later(e2fsck_t ctx,ext2_ino_t ino)56 void e2fsck_rehash_dir_later(e2fsck_t ctx, ext2_ino_t ino)
57 {
58 	if (!ctx->dirs_to_hash)
59 		ext2fs_u32_list_create(&ctx->dirs_to_hash, 50);
60 	if (ctx->dirs_to_hash)
61 		ext2fs_u32_list_add(ctx->dirs_to_hash, ino);
62 }
63 
64 /* Ask if a dir will be rebuilt during pass 3A. */
e2fsck_dir_will_be_rehashed(e2fsck_t ctx,ext2_ino_t ino)65 int e2fsck_dir_will_be_rehashed(e2fsck_t ctx, ext2_ino_t ino)
66 {
67 	if (ctx->options & E2F_OPT_COMPRESS_DIRS)
68 		return 1;
69 	if (!ctx->dirs_to_hash)
70 		return 0;
71 	return ext2fs_u32_list_test(ctx->dirs_to_hash, ino);
72 }
73 
74 #undef REHASH_DEBUG
75 
76 struct fill_dir_struct {
77 	char *buf;
78 	struct ext2_inode *inode;
79 	ext2_ino_t ino;
80 	errcode_t err;
81 	e2fsck_t ctx;
82 	struct hash_entry *harray;
83 	int max_array, num_array;
84 	unsigned int dir_size;
85 	int compress;
86 	ino_t parent;
87 	ext2_ino_t dir;
88 };
89 
90 struct hash_entry {
91 	ext2_dirhash_t	hash;
92 	ext2_dirhash_t	minor_hash;
93 	ino_t		ino;
94 	struct ext2_dir_entry	*dir;
95 };
96 
97 struct out_dir {
98 	int		num;
99 	int		max;
100 	char		*buf;
101 	ext2_dirhash_t	*hashes;
102 };
103 
fill_dir_block(ext2_filsys fs,blk64_t * block_nr,e2_blkcnt_t blockcnt,blk64_t ref_block EXT2FS_ATTR ((unused)),int ref_offset EXT2FS_ATTR ((unused)),void * priv_data)104 static int fill_dir_block(ext2_filsys fs,
105 			  blk64_t *block_nr,
106 			  e2_blkcnt_t blockcnt,
107 			  blk64_t ref_block EXT2FS_ATTR((unused)),
108 			  int ref_offset EXT2FS_ATTR((unused)),
109 			  void *priv_data)
110 {
111 	struct fill_dir_struct	*fd = (struct fill_dir_struct *) priv_data;
112 	struct hash_entry 	*new_array, *ent;
113 	struct ext2_dir_entry 	*dirent;
114 	char			*dir;
115 	unsigned int		offset, dir_offset, rec_len, name_len;
116 	int			hash_alg;
117 
118 	if (blockcnt < 0)
119 		return 0;
120 
121 	offset = blockcnt * fs->blocksize;
122 	if (offset + fs->blocksize > fd->inode->i_size) {
123 		fd->err = EXT2_ET_DIR_CORRUPTED;
124 		return BLOCK_ABORT;
125 	}
126 
127 	dir = (fd->buf+offset);
128 	if (*block_nr == 0) {
129 		memset(dir, 0, fs->blocksize);
130 		dirent = (struct ext2_dir_entry *) dir;
131 		(void) ext2fs_set_rec_len(fs, fs->blocksize, dirent);
132 	} else {
133 		int flags = fs->flags;
134 		fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
135 		fd->err = ext2fs_read_dir_block4(fs, *block_nr, dir, 0,
136 						 fd->dir);
137 		fs->flags = (flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) |
138 			    (fs->flags & ~EXT2_FLAG_IGNORE_CSUM_ERRORS);
139 		if (fd->err)
140 			return BLOCK_ABORT;
141 	}
142 	hash_alg = fs->super->s_def_hash_version;
143 	if ((hash_alg <= EXT2_HASH_TEA) &&
144 	    (fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH))
145 		hash_alg += 3;
146 	/* While the directory block is "hot", index it. */
147 	dir_offset = 0;
148 	while (dir_offset < fs->blocksize) {
149 		dirent = (struct ext2_dir_entry *) (dir + dir_offset);
150 		(void) ext2fs_get_rec_len(fs, dirent, &rec_len);
151 		name_len = ext2fs_dirent_name_len(dirent);
152 		if (((dir_offset + rec_len) > fs->blocksize) ||
153 		    (rec_len < 8) ||
154 		    ((rec_len % 4) != 0) ||
155 		    (name_len + 8 > rec_len)) {
156 			fd->err = EXT2_ET_DIR_CORRUPTED;
157 			return BLOCK_ABORT;
158 		}
159 		dir_offset += rec_len;
160 		if (dirent->inode == 0)
161 			continue;
162 		if (!fd->compress && (name_len == 1) &&
163 		    (dirent->name[0] == '.'))
164 			continue;
165 		if (!fd->compress && (name_len == 2) &&
166 		    (dirent->name[0] == '.') && (dirent->name[1] == '.')) {
167 			fd->parent = dirent->inode;
168 			continue;
169 		}
170 		if (fd->num_array >= fd->max_array) {
171 			new_array = realloc(fd->harray,
172 			    sizeof(struct hash_entry) * (fd->max_array+500));
173 			if (!new_array) {
174 				fd->err = ENOMEM;
175 				return BLOCK_ABORT;
176 			}
177 			fd->harray = new_array;
178 			fd->max_array += 500;
179 		}
180 		ent = fd->harray + fd->num_array++;
181 		ent->dir = dirent;
182 		fd->dir_size += EXT2_DIR_REC_LEN(name_len);
183 		ent->ino = dirent->inode;
184 		if (fd->compress)
185 			ent->hash = ent->minor_hash = 0;
186 		else {
187 			fd->err = ext2fs_dirhash(hash_alg, dirent->name,
188 						 name_len,
189 						 fs->super->s_hash_seed,
190 						 &ent->hash, &ent->minor_hash);
191 			if (fd->err)
192 				return BLOCK_ABORT;
193 		}
194 	}
195 
196 	return 0;
197 }
198 
199 /* Used for sorting the hash entry */
ino_cmp(const void * a,const void * b)200 static EXT2_QSORT_TYPE ino_cmp(const void *a, const void *b)
201 {
202 	const struct hash_entry *he_a = (const struct hash_entry *) a;
203 	const struct hash_entry *he_b = (const struct hash_entry *) b;
204 
205 	return (he_a->ino - he_b->ino);
206 }
207 
208 /* Used for sorting the hash entry */
name_cmp(const void * a,const void * b)209 static EXT2_QSORT_TYPE name_cmp(const void *a, const void *b)
210 {
211 	const struct hash_entry *he_a = (const struct hash_entry *) a;
212 	const struct hash_entry *he_b = (const struct hash_entry *) b;
213 	unsigned int he_a_len, he_b_len, min_len;
214 	int	ret;
215 
216 	he_a_len = ext2fs_dirent_name_len(he_a->dir);
217 	he_b_len = ext2fs_dirent_name_len(he_b->dir);
218 	min_len = he_a_len;
219 	if (min_len > he_b_len)
220 		min_len = he_b_len;
221 
222 	ret = memcmp(he_a->dir->name, he_b->dir->name, min_len);
223 	if (ret == 0) {
224 		if (he_a_len > he_b_len)
225 			ret = 1;
226 		else if (he_a_len < he_b_len)
227 			ret = -1;
228 		else
229 			ret = he_b->dir->inode - he_a->dir->inode;
230 	}
231 	return ret;
232 }
233 
234 /* Used for sorting the hash entry */
hash_cmp(const void * a,const void * b)235 static EXT2_QSORT_TYPE hash_cmp(const void *a, const void *b)
236 {
237 	const struct hash_entry *he_a = (const struct hash_entry *) a;
238 	const struct hash_entry *he_b = (const struct hash_entry *) b;
239 	int	ret;
240 
241 	if (he_a->hash > he_b->hash)
242 		ret = 1;
243 	else if (he_a->hash < he_b->hash)
244 		ret = -1;
245 	else {
246 		if (he_a->minor_hash > he_b->minor_hash)
247 			ret = 1;
248 		else if (he_a->minor_hash < he_b->minor_hash)
249 			ret = -1;
250 		else
251 			ret = name_cmp(a, b);
252 	}
253 	return ret;
254 }
255 
alloc_size_dir(ext2_filsys fs,struct out_dir * outdir,int blocks)256 static errcode_t alloc_size_dir(ext2_filsys fs, struct out_dir *outdir,
257 				int blocks)
258 {
259 	void			*new_mem;
260 
261 	if (outdir->max) {
262 		new_mem = realloc(outdir->buf, blocks * fs->blocksize);
263 		if (!new_mem)
264 			return ENOMEM;
265 		outdir->buf = new_mem;
266 		new_mem = realloc(outdir->hashes,
267 				  blocks * sizeof(ext2_dirhash_t));
268 		if (!new_mem)
269 			return ENOMEM;
270 		outdir->hashes = new_mem;
271 	} else {
272 		outdir->buf = malloc(blocks * fs->blocksize);
273 		outdir->hashes = malloc(blocks * sizeof(ext2_dirhash_t));
274 		outdir->num = 0;
275 	}
276 	outdir->max = blocks;
277 	return 0;
278 }
279 
free_out_dir(struct out_dir * outdir)280 static void free_out_dir(struct out_dir *outdir)
281 {
282 	free(outdir->buf);
283 	free(outdir->hashes);
284 	outdir->max = 0;
285 	outdir->num =0;
286 }
287 
get_next_block(ext2_filsys fs,struct out_dir * outdir,char ** ret)288 static errcode_t get_next_block(ext2_filsys fs, struct out_dir *outdir,
289 			 char ** ret)
290 {
291 	errcode_t	retval;
292 
293 	if (outdir->num >= outdir->max) {
294 		retval = alloc_size_dir(fs, outdir, outdir->max + 50);
295 		if (retval)
296 			return retval;
297 	}
298 	*ret = outdir->buf + (outdir->num++ * fs->blocksize);
299 	memset(*ret, 0, fs->blocksize);
300 	return 0;
301 }
302 
303 /*
304  * This function is used to make a unique filename.  We do this by
305  * appending ~0, and then incrementing the number.  However, we cannot
306  * expand the length of the filename beyond the padding available in
307  * the directory entry.
308  */
mutate_name(char * str,unsigned int * len)309 static void mutate_name(char *str, unsigned int *len)
310 {
311 	int i;
312 	unsigned int l = *len;
313 
314 	/*
315 	 * First check to see if it looks the name has been mutated
316 	 * already
317 	 */
318 	for (i = l-1; i > 0; i--) {
319 		if (!isdigit(str[i]))
320 			break;
321 	}
322 	if ((i == (int)l - 1) || (str[i] != '~')) {
323 		if (((l-1) & 3) < 2)
324 			l += 2;
325 		else
326 			l = (l+3) & ~3;
327 		str[l-2] = '~';
328 		str[l-1] = '0';
329 		*len = l;
330 		return;
331 	}
332 	for (i = l-1; i >= 0; i--) {
333 		if (isdigit(str[i])) {
334 			if (str[i] == '9')
335 				str[i] = '0';
336 			else {
337 				str[i]++;
338 				return;
339 			}
340 			continue;
341 		}
342 		if (i == 1) {
343 			if (str[0] == 'z')
344 				str[0] = 'A';
345 			else if (str[0] == 'Z') {
346 				str[0] = '~';
347 				str[1] = '0';
348 			} else
349 				str[0]++;
350 		} else if (i > 0) {
351 			str[i] = '1';
352 			str[i-1] = '~';
353 		} else {
354 			if (str[0] == '~')
355 				str[0] = 'a';
356 			else
357 				str[0]++;
358 		}
359 		break;
360 	}
361 }
362 
duplicate_search_and_fix(e2fsck_t ctx,ext2_filsys fs,ext2_ino_t ino,struct fill_dir_struct * fd)363 static int duplicate_search_and_fix(e2fsck_t ctx, ext2_filsys fs,
364 				    ext2_ino_t ino,
365 				    struct fill_dir_struct *fd)
366 {
367 	struct problem_context	pctx;
368 	struct hash_entry 	*ent, *prev;
369 	int			i, j;
370 	int			fixed = 0;
371 	char			new_name[256];
372 	unsigned int		new_len;
373 	int			hash_alg;
374 
375 	clear_problem_context(&pctx);
376 	pctx.ino = ino;
377 
378 	hash_alg = fs->super->s_def_hash_version;
379 	if ((hash_alg <= EXT2_HASH_TEA) &&
380 	    (fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH))
381 		hash_alg += 3;
382 
383 	for (i=1; i < fd->num_array; i++) {
384 		ent = fd->harray + i;
385 		prev = ent - 1;
386 		if (!ent->dir->inode ||
387 		    (ext2fs_dirent_name_len(ent->dir) !=
388 		     ext2fs_dirent_name_len(prev->dir)) ||
389 		    memcmp(ent->dir->name, prev->dir->name,
390 			     ext2fs_dirent_name_len(ent->dir)))
391 			continue;
392 		pctx.dirent = ent->dir;
393 		if ((ent->dir->inode == prev->dir->inode) &&
394 		    fix_problem(ctx, PR_2_DUPLICATE_DIRENT, &pctx)) {
395 			e2fsck_adjust_inode_count(ctx, ent->dir->inode, -1);
396 			ent->dir->inode = 0;
397 			fixed++;
398 			continue;
399 		}
400 		new_len = ext2fs_dirent_name_len(ent->dir);
401 		memcpy(new_name, ent->dir->name, new_len);
402 		mutate_name(new_name, &new_len);
403 		for (j=0; j < fd->num_array; j++) {
404 			if ((i==j) ||
405 			    (new_len !=
406 			     (unsigned) ext2fs_dirent_name_len(fd->harray[j].dir)) ||
407 			    memcmp(new_name, fd->harray[j].dir->name, new_len))
408 				continue;
409 			mutate_name(new_name, &new_len);
410 
411 			j = -1;
412 		}
413 		new_name[new_len] = 0;
414 		pctx.str = new_name;
415 		if (fix_problem(ctx, PR_2_NON_UNIQUE_FILE, &pctx)) {
416 			memcpy(ent->dir->name, new_name, new_len);
417 			ext2fs_dirent_set_name_len(ent->dir, new_len);
418 			ext2fs_dirhash(hash_alg, new_name, new_len,
419 				       fs->super->s_hash_seed,
420 				       &ent->hash, &ent->minor_hash);
421 			fixed++;
422 		}
423 	}
424 	return fixed;
425 }
426 
427 
copy_dir_entries(e2fsck_t ctx,struct fill_dir_struct * fd,struct out_dir * outdir)428 static errcode_t copy_dir_entries(e2fsck_t ctx,
429 				  struct fill_dir_struct *fd,
430 				  struct out_dir *outdir)
431 {
432 	ext2_filsys 		fs = ctx->fs;
433 	errcode_t		retval;
434 	char			*block_start;
435 	struct hash_entry 	*ent;
436 	struct ext2_dir_entry	*dirent;
437 	unsigned int		rec_len, prev_rec_len, left, slack, offset;
438 	int			i;
439 	ext2_dirhash_t		prev_hash;
440 	int			csum_size = 0;
441 	struct			ext2_dir_entry_tail *t;
442 
443 	if (ctx->htree_slack_percentage == 255) {
444 		profile_get_uint(ctx->profile, "options",
445 				 "indexed_dir_slack_percentage",
446 				 0, 20,
447 				 &ctx->htree_slack_percentage);
448 		if (ctx->htree_slack_percentage > 100)
449 			ctx->htree_slack_percentage = 20;
450 	}
451 
452 	if (ext2fs_has_feature_metadata_csum(fs->super))
453 		csum_size = sizeof(struct ext2_dir_entry_tail);
454 
455 	outdir->max = 0;
456 	retval = alloc_size_dir(fs, outdir,
457 				(fd->dir_size / fs->blocksize) + 2);
458 	if (retval)
459 		return retval;
460 	outdir->num = fd->compress ? 0 : 1;
461 	offset = 0;
462 	outdir->hashes[0] = 0;
463 	prev_hash = 1;
464 	if ((retval = get_next_block(fs, outdir, &block_start)))
465 		return retval;
466 	dirent = (struct ext2_dir_entry *) block_start;
467 	prev_rec_len = 0;
468 	rec_len = 0;
469 	left = fs->blocksize - csum_size;
470 	slack = fd->compress ? 12 :
471 		((fs->blocksize - csum_size) * ctx->htree_slack_percentage)/100;
472 	if (slack < 12)
473 		slack = 12;
474 	for (i = 0; i < fd->num_array; i++) {
475 		ent = fd->harray + i;
476 		if (ent->dir->inode == 0)
477 			continue;
478 		rec_len = EXT2_DIR_REC_LEN(ext2fs_dirent_name_len(ent->dir));
479 		if (rec_len > left) {
480 			if (left) {
481 				left += prev_rec_len;
482 				retval = ext2fs_set_rec_len(fs, left, dirent);
483 				if (retval)
484 					return retval;
485 			}
486 			if (csum_size) {
487 				t = EXT2_DIRENT_TAIL(block_start,
488 						     fs->blocksize);
489 				ext2fs_initialize_dirent_tail(fs, t);
490 			}
491 			if ((retval = get_next_block(fs, outdir,
492 						      &block_start)))
493 				return retval;
494 			offset = 0;
495 		}
496 		left = (fs->blocksize - csum_size) - offset;
497 		dirent = (struct ext2_dir_entry *) (block_start + offset);
498 		if (offset == 0) {
499 			if (ent->hash == prev_hash)
500 				outdir->hashes[outdir->num-1] = ent->hash | 1;
501 			else
502 				outdir->hashes[outdir->num-1] = ent->hash;
503 		}
504 		dirent->inode = ent->dir->inode;
505 		ext2fs_dirent_set_name_len(dirent,
506 					   ext2fs_dirent_name_len(ent->dir));
507 		ext2fs_dirent_set_file_type(dirent,
508 					    ext2fs_dirent_file_type(ent->dir));
509 		retval = ext2fs_set_rec_len(fs, rec_len, dirent);
510 		if (retval)
511 			return retval;
512 		prev_rec_len = rec_len;
513 		memcpy(dirent->name, ent->dir->name,
514 		       ext2fs_dirent_name_len(dirent));
515 		offset += rec_len;
516 		left -= rec_len;
517 		if (left < slack) {
518 			prev_rec_len += left;
519 			retval = ext2fs_set_rec_len(fs, prev_rec_len, dirent);
520 			if (retval)
521 				return retval;
522 			offset += left;
523 			left = 0;
524 		}
525 		prev_hash = ent->hash;
526 	}
527 	if (left)
528 		retval = ext2fs_set_rec_len(fs, rec_len + left, dirent);
529 	if (csum_size) {
530 		t = EXT2_DIRENT_TAIL(block_start, fs->blocksize);
531 		ext2fs_initialize_dirent_tail(fs, t);
532 	}
533 
534 	return retval;
535 }
536 
537 
set_root_node(ext2_filsys fs,char * buf,ext2_ino_t ino,ext2_ino_t parent)538 static struct ext2_dx_root_info *set_root_node(ext2_filsys fs, char *buf,
539 				    ext2_ino_t ino, ext2_ino_t parent)
540 {
541 	struct ext2_dir_entry 		*dir;
542 	struct ext2_dx_root_info  	*root;
543 	struct ext2_dx_countlimit	*limits;
544 	int				filetype = 0;
545 	int				csum_size = 0;
546 
547 	if (ext2fs_has_feature_filetype(fs->super))
548 		filetype = EXT2_FT_DIR;
549 
550 	memset(buf, 0, fs->blocksize);
551 	dir = (struct ext2_dir_entry *) buf;
552 	dir->inode = ino;
553 	dir->name[0] = '.';
554 	ext2fs_dirent_set_name_len(dir, 1);
555 	ext2fs_dirent_set_file_type(dir, filetype);
556 	dir->rec_len = 12;
557 	dir = (struct ext2_dir_entry *) (buf + 12);
558 	dir->inode = parent;
559 	dir->name[0] = '.';
560 	dir->name[1] = '.';
561 	ext2fs_dirent_set_name_len(dir, 2);
562 	ext2fs_dirent_set_file_type(dir, filetype);
563 	dir->rec_len = fs->blocksize - 12;
564 
565 	root = (struct ext2_dx_root_info *) (buf+24);
566 	root->reserved_zero = 0;
567 	root->hash_version = fs->super->s_def_hash_version;
568 	root->info_length = 8;
569 	root->indirect_levels = 0;
570 	root->unused_flags = 0;
571 
572 	if (ext2fs_has_feature_metadata_csum(fs->super))
573 		csum_size = sizeof(struct ext2_dx_tail);
574 
575 	limits = (struct ext2_dx_countlimit *) (buf+32);
576 	limits->limit = (fs->blocksize - (32 + csum_size)) /
577 			sizeof(struct ext2_dx_entry);
578 	limits->count = 0;
579 
580 	return root;
581 }
582 
583 
set_int_node(ext2_filsys fs,char * buf)584 static struct ext2_dx_entry *set_int_node(ext2_filsys fs, char *buf)
585 {
586 	struct ext2_dir_entry 		*dir;
587 	struct ext2_dx_countlimit	*limits;
588 	int				csum_size = 0;
589 
590 	memset(buf, 0, fs->blocksize);
591 	dir = (struct ext2_dir_entry *) buf;
592 	dir->inode = 0;
593 	(void) ext2fs_set_rec_len(fs, fs->blocksize, dir);
594 
595 	if (ext2fs_has_feature_metadata_csum(fs->super))
596 		csum_size = sizeof(struct ext2_dx_tail);
597 
598 	limits = (struct ext2_dx_countlimit *) (buf+8);
599 	limits->limit = (fs->blocksize - (8 + csum_size)) /
600 			sizeof(struct ext2_dx_entry);
601 	limits->count = 0;
602 
603 	return (struct ext2_dx_entry *) limits;
604 }
605 
alloc_blocks(ext2_filsys fs,struct ext2_dx_countlimit ** limit,struct ext2_dx_entry ** prev_ent,struct ext2_dx_entry ** next_ent,int * prev_offset,int * next_offset,struct out_dir * outdir,int i,int * prev_count,int * next_count)606 static int alloc_blocks(ext2_filsys fs,
607 			struct ext2_dx_countlimit **limit,
608 			struct ext2_dx_entry **prev_ent,
609 			struct ext2_dx_entry **next_ent,
610 			int *prev_offset, int *next_offset,
611 			struct out_dir *outdir, int i,
612 			int *prev_count, int *next_count)
613 {
614 	errcode_t	retval;
615 	char		*block_start;
616 
617 	if (*limit)
618 		(*limit)->limit = (*limit)->count =
619 			ext2fs_cpu_to_le16((*limit)->limit);
620 	*prev_ent = (struct ext2_dx_entry *) (outdir->buf + *prev_offset);
621 	(*prev_ent)->block = ext2fs_cpu_to_le32(outdir->num);
622 
623 	if (i != 1)
624 		(*prev_ent)->hash =
625 			ext2fs_cpu_to_le32(outdir->hashes[i]);
626 
627 	retval = get_next_block(fs, outdir, &block_start);
628 	if (retval)
629 		return retval;
630 
631 	*next_ent = set_int_node(fs, block_start);
632 	*limit = (struct ext2_dx_countlimit *)(*next_ent);
633 	if (next_offset)
634 		*next_offset = ((char *) *next_ent - outdir->buf);
635 
636 	*next_count = (*limit)->limit;
637 	(*prev_offset) += sizeof(struct ext2_dx_entry);
638 	(*prev_count)--;
639 
640 	return 0;
641 }
642 
643 /*
644  * This function takes the leaf nodes which have been written in
645  * outdir, and populates the root node and any necessary interior nodes.
646  */
calculate_tree(ext2_filsys fs,struct out_dir * outdir,ext2_ino_t ino,ext2_ino_t parent)647 static errcode_t calculate_tree(ext2_filsys fs,
648 				struct out_dir *outdir,
649 				ext2_ino_t ino,
650 				ext2_ino_t parent)
651 {
652 	struct ext2_dx_root_info	*root_info;
653 	struct ext2_dx_entry		*root, *int_ent, *dx_ent = 0;
654 	struct ext2_dx_countlimit	*root_limit, *int_limit, *limit;
655 	errcode_t			retval;
656 	int				i, c1, c2, c3, nblks;
657 	int				limit_offset, int_offset, root_offset;
658 
659 	root_info = set_root_node(fs, outdir->buf, ino, parent);
660 	root_offset = limit_offset = ((char *) root_info - outdir->buf) +
661 		root_info->info_length;
662 	root_limit = (struct ext2_dx_countlimit *) (outdir->buf + limit_offset);
663 	c1 = root_limit->limit;
664 	nblks = outdir->num;
665 
666 	/* Write out the pointer blocks */
667 	if (nblks - 1 <= c1) {
668 		/* Just write out the root block, and we're done */
669 		root = (struct ext2_dx_entry *) (outdir->buf + root_offset);
670 		for (i=1; i < nblks; i++) {
671 			root->block = ext2fs_cpu_to_le32(i);
672 			if (i != 1)
673 				root->hash =
674 					ext2fs_cpu_to_le32(outdir->hashes[i]);
675 			root++;
676 			c1--;
677 		}
678 	} else if (nblks - 1 <= ext2fs_htree_intnode_maxrecs(fs, c1)) {
679 		c2 = 0;
680 		limit = NULL;
681 		root_info->indirect_levels = 1;
682 		for (i=1; i < nblks; i++) {
683 			if (c2 == 0 && c1 == 0)
684 				return ENOSPC;
685 			if (c2 == 0) {
686 				retval = alloc_blocks(fs, &limit, &root,
687 						      &dx_ent, &root_offset,
688 						      NULL, outdir, i, &c1,
689 						      &c2);
690 				if (retval)
691 					return retval;
692 			}
693 			dx_ent->block = ext2fs_cpu_to_le32(i);
694 			if (c2 != limit->limit)
695 				dx_ent->hash =
696 					ext2fs_cpu_to_le32(outdir->hashes[i]);
697 			dx_ent++;
698 			c2--;
699 		}
700 		limit->count = ext2fs_cpu_to_le16(limit->limit - c2);
701 		limit->limit = ext2fs_cpu_to_le16(limit->limit);
702 	} else {
703 		c2 = 0;
704 		c3 = 0;
705 		limit = NULL;
706 		int_limit = 0;
707 		root_info->indirect_levels = 2;
708 		for (i = 1; i < nblks; i++) {
709 			if (c3 == 0 && c2 == 0 && c1 == 0)
710 				return ENOSPC;
711 			if (c3 == 0 && c2 == 0) {
712 				retval = alloc_blocks(fs, &int_limit, &root,
713 						      &int_ent, &root_offset,
714 						      &int_offset, outdir, i,
715 						      &c1, &c2);
716 				if (retval)
717 					return retval;
718 			}
719 			if (c3 == 0) {
720 				retval = alloc_blocks(fs, &limit, &int_ent,
721 						      &dx_ent, &int_offset,
722 						      NULL, outdir, i, &c2,
723 						      &c3);
724 				if (retval)
725 					return retval;
726 
727 			}
728 			dx_ent->block = ext2fs_cpu_to_le32(i);
729 			if (c3 != limit->limit)
730 				dx_ent->hash =
731 					ext2fs_cpu_to_le32(outdir->hashes[i]);
732 			dx_ent++;
733 			c3--;
734 		}
735 		int_limit->count = ext2fs_cpu_to_le16(limit->limit - c2);
736 		int_limit->limit = ext2fs_cpu_to_le16(limit->limit);
737 
738 		limit->count = ext2fs_cpu_to_le16(limit->limit - c3);
739 		limit->limit = ext2fs_cpu_to_le16(limit->limit);
740 
741 	}
742 	root_limit = (struct ext2_dx_countlimit *) (outdir->buf + limit_offset);
743 	root_limit->count = ext2fs_cpu_to_le16(root_limit->limit - c1);
744 	root_limit->limit = ext2fs_cpu_to_le16(root_limit->limit);
745 
746 	return 0;
747 }
748 
749 struct write_dir_struct {
750 	struct out_dir *outdir;
751 	errcode_t	err;
752 	ext2_ino_t	ino;
753 	e2fsck_t	ctx;
754 	ext2_ino_t	dir;
755 };
756 
757 /*
758  * Helper function which writes out a directory block.
759  */
write_dir_block(ext2_filsys fs,blk64_t * block_nr,e2_blkcnt_t blockcnt,blk64_t ref_block EXT2FS_ATTR ((unused)),int ref_offset EXT2FS_ATTR ((unused)),void * priv_data)760 static int write_dir_block(ext2_filsys fs,
761 			   blk64_t *block_nr,
762 			   e2_blkcnt_t blockcnt,
763 			   blk64_t ref_block EXT2FS_ATTR((unused)),
764 			   int ref_offset EXT2FS_ATTR((unused)),
765 			   void *priv_data)
766 {
767 	struct write_dir_struct	*wd = (struct write_dir_struct *) priv_data;
768 	char	*dir, *buf = 0;
769 
770 #ifdef REHASH_DEBUG
771 	printf("%u: write_dir_block %lld:%lld", wd->ino, blockcnt, *block_nr);
772 #endif
773 	if ((*block_nr == 0) || (blockcnt < 0)) {
774 #ifdef REHASH_DEBUG
775 		printf(" - skip\n");
776 #endif
777 		return 0;
778 	}
779 	if (blockcnt < wd->outdir->num)
780 		dir = wd->outdir->buf + (blockcnt * fs->blocksize);
781 	else if (wd->ctx->lost_and_found == wd->dir) {
782 		/* Don't release any extra directory blocks for lost+found */
783 		wd->err = ext2fs_new_dir_block(fs, 0, 0, &buf);
784 		if (wd->err)
785 			return BLOCK_ABORT;
786 		dir = buf;
787 		wd->outdir->num++;
788 	} else {
789 		/* Don't free blocks at the end of the directory, they
790 		 * will be truncated by the caller. */
791 #ifdef REHASH_DEBUG
792 		printf(" - not freed\n");
793 #endif
794 		return 0;
795 	}
796 	wd->err = ext2fs_write_dir_block4(fs, *block_nr, dir, 0, wd->dir);
797 	if (buf)
798 		ext2fs_free_mem(&buf);
799 
800 #ifdef REHASH_DEBUG
801 	printf(" - write (%d)\n", wd->err);
802 #endif
803 	if (wd->err)
804 		return BLOCK_ABORT;
805 	return 0;
806 }
807 
write_directory(e2fsck_t ctx,ext2_filsys fs,struct out_dir * outdir,ext2_ino_t ino,struct ext2_inode * inode,int compress)808 static errcode_t write_directory(e2fsck_t ctx, ext2_filsys fs,
809 				 struct out_dir *outdir,
810 				 ext2_ino_t ino, struct ext2_inode *inode,
811 				 int compress)
812 {
813 	struct write_dir_struct wd;
814 	errcode_t	retval;
815 
816 	retval = e2fsck_expand_directory(ctx, ino, -1, outdir->num);
817 	if (retval)
818 		return retval;
819 
820 	wd.outdir = outdir;
821 	wd.err = 0;
822 	wd.ino = ino;
823 	wd.ctx = ctx;
824 	wd.dir = ino;
825 
826 	retval = ext2fs_block_iterate3(fs, ino, 0, NULL,
827 				       write_dir_block, &wd);
828 	if (retval)
829 		return retval;
830 	if (wd.err)
831 		return wd.err;
832 
833 	e2fsck_read_inode(ctx, ino, inode, "rehash_dir");
834 	if (compress)
835 		inode->i_flags &= ~EXT2_INDEX_FL;
836 	else
837 		inode->i_flags |= EXT2_INDEX_FL;
838 #ifdef REHASH_DEBUG
839 	printf("%u: set inode size to %u blocks = %u bytes\n",
840 	       ino, outdir->num, outdir->num * fs->blocksize);
841 #endif
842 	retval = ext2fs_inode_size_set(fs, inode, (ext2_off64_t)outdir->num *
843 						   fs->blocksize);
844 	if (retval)
845 		return retval;
846 
847 	/* ext2fs_punch() calls ext2fs_write_inode() which writes the size */
848 	return ext2fs_punch(fs, ino, inode, NULL, outdir->num, ~0ULL);
849 }
850 
e2fsck_rehash_dir(e2fsck_t ctx,ext2_ino_t ino,struct problem_context * pctx)851 errcode_t e2fsck_rehash_dir(e2fsck_t ctx, ext2_ino_t ino,
852 			    struct problem_context *pctx)
853 {
854 	ext2_filsys 		fs = ctx->fs;
855 	errcode_t		retval;
856 	struct ext2_inode 	inode;
857 	char			*dir_buf = 0;
858 	struct fill_dir_struct	fd = { NULL, NULL, 0, 0, 0, NULL,
859 				       0, 0, 0, 0, 0, 0 };
860 	struct out_dir		outdir = { 0, 0, 0, 0 };
861 
862 	e2fsck_read_inode(ctx, ino, &inode, "rehash_dir");
863 
864 	if (ext2fs_has_feature_inline_data(fs->super) &&
865 	   (inode.i_flags & EXT4_INLINE_DATA_FL))
866 		return 0;
867 
868 	retval = ENOMEM;
869 	dir_buf = malloc(inode.i_size);
870 	if (!dir_buf)
871 		goto errout;
872 
873 	fd.max_array = inode.i_size / 32;
874 	fd.harray = malloc(fd.max_array * sizeof(struct hash_entry));
875 	if (!fd.harray)
876 		goto errout;
877 
878 	fd.ino = ino;
879 	fd.ctx = ctx;
880 	fd.buf = dir_buf;
881 	fd.inode = &inode;
882 	fd.dir = ino;
883 	if (!ext2fs_has_feature_dir_index(fs->super) ||
884 	    (inode.i_size / fs->blocksize) < 2)
885 		fd.compress = 1;
886 	fd.parent = 0;
887 
888 retry_nohash:
889 	/* Read in the entire directory into memory */
890 	retval = ext2fs_block_iterate3(fs, ino, 0, 0,
891 				       fill_dir_block, &fd);
892 	if (fd.err) {
893 		retval = fd.err;
894 		goto errout;
895 	}
896 
897 	/*
898 	 * If the entries read are less than a block, then don't index
899 	 * the directory
900 	 */
901 	if (!fd.compress && (fd.dir_size < (fs->blocksize - 24))) {
902 		fd.compress = 1;
903 		fd.dir_size = 0;
904 		fd.num_array = 0;
905 		goto retry_nohash;
906 	}
907 
908 #if 0
909 	printf("%d entries (%d bytes) found in inode %d\n",
910 	       fd.num_array, fd.dir_size, ino);
911 #endif
912 
913 	/* Sort the list */
914 resort:
915 	if (fd.compress && fd.num_array > 1)
916 		qsort(fd.harray+2, fd.num_array-2, sizeof(struct hash_entry),
917 		      hash_cmp);
918 	else
919 		qsort(fd.harray, fd.num_array, sizeof(struct hash_entry),
920 		      hash_cmp);
921 
922 	/*
923 	 * Look for duplicates
924 	 */
925 	if (duplicate_search_and_fix(ctx, fs, ino, &fd))
926 		goto resort;
927 
928 	if (ctx->options & E2F_OPT_NO) {
929 		retval = 0;
930 		goto errout;
931 	}
932 
933 	/* Sort non-hashed directories by inode number */
934 	if (fd.compress && fd.num_array > 1)
935 		qsort(fd.harray+2, fd.num_array-2,
936 		      sizeof(struct hash_entry), ino_cmp);
937 
938 	/*
939 	 * Copy the directory entries.  In a htree directory these
940 	 * will become the leaf nodes.
941 	 */
942 	retval = copy_dir_entries(ctx, &fd, &outdir);
943 	if (retval)
944 		goto errout;
945 
946 	free(dir_buf); dir_buf = 0;
947 
948 	if (!fd.compress) {
949 		/* Calculate the interior nodes */
950 		retval = calculate_tree(fs, &outdir, ino, fd.parent);
951 		if (retval)
952 			goto errout;
953 	}
954 
955 	retval = write_directory(ctx, fs, &outdir, ino, &inode, fd.compress);
956 	if (retval)
957 		goto errout;
958 
959 	if (ctx->options & E2F_OPT_CONVERT_BMAP)
960 		retval = e2fsck_rebuild_extents_later(ctx, ino);
961 	else
962 		retval = e2fsck_check_rebuild_extents(ctx, ino, &inode, pctx);
963 errout:
964 	free(dir_buf);
965 	free(fd.harray);
966 
967 	free_out_dir(&outdir);
968 	return retval;
969 }
970 
e2fsck_rehash_directories(e2fsck_t ctx)971 void e2fsck_rehash_directories(e2fsck_t ctx)
972 {
973 	struct problem_context	pctx;
974 #ifdef RESOURCE_TRACK
975 	struct resource_track	rtrack;
976 #endif
977 	struct dir_info		*dir;
978 	ext2_u32_iterate 	iter;
979 	struct dir_info_iter *	dirinfo_iter = 0;
980 	ext2_ino_t		ino;
981 	errcode_t		retval;
982 	int			cur, max, all_dirs, first = 1;
983 
984 	init_resource_track(&rtrack, ctx->fs->io);
985 	all_dirs = ctx->options & E2F_OPT_COMPRESS_DIRS;
986 
987 	if (!ctx->dirs_to_hash && !all_dirs)
988 		return;
989 
990 	(void) e2fsck_get_lost_and_found(ctx, 0);
991 
992 	clear_problem_context(&pctx);
993 
994 	cur = 0;
995 	if (all_dirs) {
996 		dirinfo_iter = e2fsck_dir_info_iter_begin(ctx);
997 		max = e2fsck_get_num_dirinfo(ctx);
998 	} else {
999 		retval = ext2fs_u32_list_iterate_begin(ctx->dirs_to_hash,
1000 						       &iter);
1001 		if (retval) {
1002 			pctx.errcode = retval;
1003 			fix_problem(ctx, PR_3A_OPTIMIZE_ITER, &pctx);
1004 			return;
1005 		}
1006 		max = ext2fs_u32_list_count(ctx->dirs_to_hash);
1007 	}
1008 	while (1) {
1009 		if (all_dirs) {
1010 			if ((dir = e2fsck_dir_info_iter(ctx,
1011 							dirinfo_iter)) == 0)
1012 				break;
1013 			ino = dir->ino;
1014 		} else {
1015 			if (!ext2fs_u32_list_iterate(iter, &ino))
1016 				break;
1017 		}
1018 
1019 		pctx.dir = ino;
1020 		if (first) {
1021 			fix_problem(ctx, PR_3A_PASS_HEADER, &pctx);
1022 			first = 0;
1023 		}
1024 #if 0
1025 		fix_problem(ctx, PR_3A_OPTIMIZE_DIR, &pctx);
1026 #endif
1027 		pctx.errcode = e2fsck_rehash_dir(ctx, ino, &pctx);
1028 		if (pctx.errcode) {
1029 			end_problem_latch(ctx, PR_LATCH_OPTIMIZE_DIR);
1030 			fix_problem(ctx, PR_3A_OPTIMIZE_DIR_ERR, &pctx);
1031 		}
1032 		if (ctx->progress && !ctx->progress_fd)
1033 			e2fsck_simple_progress(ctx, "Rebuilding directory",
1034 			       100.0 * (float) (++cur) / (float) max, ino);
1035 	}
1036 	end_problem_latch(ctx, PR_LATCH_OPTIMIZE_DIR);
1037 	if (all_dirs)
1038 		e2fsck_dir_info_iter_end(ctx, dirinfo_iter);
1039 	else
1040 		ext2fs_u32_list_iterate_end(iter);
1041 
1042 	if (ctx->dirs_to_hash)
1043 		ext2fs_u32_list_free(ctx->dirs_to_hash);
1044 	ctx->dirs_to_hash = 0;
1045 
1046 	print_resource_track(ctx, "Pass 3A", &rtrack, ctx->fs->io);
1047 }
1048