Home | History | Annotate | Download | only in e2fsck
      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 <string.h>
     49 #include <ctype.h>
     50 #include <errno.h>
     51 #include "e2fsck.h"
     52 #include "problem.h"
     53 
     54 struct fill_dir_struct {
     55 	char *buf;
     56 	struct ext2_inode *inode;
     57 	errcode_t err;
     58 	e2fsck_t ctx;
     59 	struct hash_entry *harray;
     60 	int max_array, num_array;
     61 	unsigned int dir_size;
     62 	int compress;
     63 	ino_t parent;
     64 };
     65 
     66 struct hash_entry {
     67 	ext2_dirhash_t	hash;
     68 	ext2_dirhash_t	minor_hash;
     69 	ino_t		ino;
     70 	struct ext2_dir_entry	*dir;
     71 };
     72 
     73 struct out_dir {
     74 	int		num;
     75 	int		max;
     76 	char		*buf;
     77 	ext2_dirhash_t	*hashes;
     78 };
     79 
     80 static int fill_dir_block(ext2_filsys fs,
     81 			  blk64_t *block_nr,
     82 			  e2_blkcnt_t blockcnt,
     83 			  blk64_t ref_block EXT2FS_ATTR((unused)),
     84 			  int ref_offset EXT2FS_ATTR((unused)),
     85 			  void *priv_data)
     86 {
     87 	struct fill_dir_struct	*fd = (struct fill_dir_struct *) priv_data;
     88 	struct hash_entry 	*new_array, *ent;
     89 	struct ext2_dir_entry 	*dirent;
     90 	char			*dir;
     91 	unsigned int		offset, dir_offset, rec_len;
     92 	int			hash_alg;
     93 
     94 	if (blockcnt < 0)
     95 		return 0;
     96 
     97 	offset = blockcnt * fs->blocksize;
     98 	if (offset + fs->blocksize > fd->inode->i_size) {
     99 		fd->err = EXT2_ET_DIR_CORRUPTED;
    100 		return BLOCK_ABORT;
    101 	}
    102 	dir = (fd->buf+offset);
    103 	if (HOLE_BLKADDR(*block_nr)) {
    104 		memset(dir, 0, fs->blocksize);
    105 		dirent = (struct ext2_dir_entry *) dir;
    106 		(void) ext2fs_set_rec_len(fs, fs->blocksize, dirent);
    107 	} else {
    108 		fd->err = ext2fs_read_dir_block3(fs, *block_nr, dir, 0);
    109 		if (fd->err)
    110 			return BLOCK_ABORT;
    111 	}
    112 	hash_alg = fs->super->s_def_hash_version;
    113 	if ((hash_alg <= EXT2_HASH_TEA) &&
    114 	    (fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH))
    115 		hash_alg += 3;
    116 	/* While the directory block is "hot", index it. */
    117 	dir_offset = 0;
    118 	while (dir_offset < fs->blocksize) {
    119 		dirent = (struct ext2_dir_entry *) (dir + dir_offset);
    120 		(void) ext2fs_get_rec_len(fs, dirent, &rec_len);
    121 		if (((dir_offset + rec_len) > fs->blocksize) ||
    122 		    (rec_len < 8) ||
    123 		    ((rec_len % 4) != 0) ||
    124 		    (((dirent->name_len & 0xFF)+8U) > rec_len)) {
    125 			fd->err = EXT2_ET_DIR_CORRUPTED;
    126 			return BLOCK_ABORT;
    127 		}
    128 		dir_offset += rec_len;
    129 		if (dirent->inode == 0)
    130 			continue;
    131 		if (!fd->compress && ((dirent->name_len&0xFF) == 1) &&
    132 		    (dirent->name[0] == '.'))
    133 			continue;
    134 		if (!fd->compress && ((dirent->name_len&0xFF) == 2) &&
    135 		    (dirent->name[0] == '.') && (dirent->name[1] == '.')) {
    136 			fd->parent = dirent->inode;
    137 			continue;
    138 		}
    139 		if (fd->num_array >= fd->max_array) {
    140 			new_array = realloc(fd->harray,
    141 			    sizeof(struct hash_entry) * (fd->max_array+500));
    142 			if (!new_array) {
    143 				fd->err = ENOMEM;
    144 				return BLOCK_ABORT;
    145 			}
    146 			fd->harray = new_array;
    147 			fd->max_array += 500;
    148 		}
    149 		ent = fd->harray + fd->num_array++;
    150 		ent->dir = dirent;
    151 		fd->dir_size += EXT2_DIR_REC_LEN(dirent->name_len & 0xFF);
    152 		ent->ino = dirent->inode;
    153 		if (fd->compress)
    154 			ent->hash = ent->minor_hash = 0;
    155 		else {
    156 			fd->err = ext2fs_dirhash(hash_alg, dirent->name,
    157 						 dirent->name_len & 0xFF,
    158 						 fs->super->s_hash_seed,
    159 						 &ent->hash, &ent->minor_hash);
    160 			if (fd->err)
    161 				return BLOCK_ABORT;
    162 		}
    163 	}
    164 
    165 	return 0;
    166 }
    167 
    168 /* Used for sorting the hash entry */
    169 static EXT2_QSORT_TYPE ino_cmp(const void *a, const void *b)
    170 {
    171 	const struct hash_entry *he_a = (const struct hash_entry *) a;
    172 	const struct hash_entry *he_b = (const struct hash_entry *) b;
    173 
    174 	return (he_a->ino - he_b->ino);
    175 }
    176 
    177 /* Used for sorting the hash entry */
    178 static EXT2_QSORT_TYPE name_cmp(const void *a, const void *b)
    179 {
    180 	const struct hash_entry *he_a = (const struct hash_entry *) a;
    181 	const struct hash_entry *he_b = (const struct hash_entry *) b;
    182 	int	ret;
    183 	int	min_len;
    184 
    185 	min_len = he_a->dir->name_len;
    186 	if (min_len > he_b->dir->name_len)
    187 		min_len = he_b->dir->name_len;
    188 
    189 	ret = strncmp(he_a->dir->name, he_b->dir->name, min_len);
    190 	if (ret == 0) {
    191 		if (he_a->dir->name_len > he_b->dir->name_len)
    192 			ret = 1;
    193 		else if (he_a->dir->name_len < he_b->dir->name_len)
    194 			ret = -1;
    195 		else
    196 			ret = he_b->dir->inode - he_a->dir->inode;
    197 	}
    198 	return ret;
    199 }
    200 
    201 /* Used for sorting the hash entry */
    202 static EXT2_QSORT_TYPE hash_cmp(const void *a, const void *b)
    203 {
    204 	const struct hash_entry *he_a = (const struct hash_entry *) a;
    205 	const struct hash_entry *he_b = (const struct hash_entry *) b;
    206 	int	ret;
    207 
    208 	if (he_a->hash > he_b->hash)
    209 		ret = 1;
    210 	else if (he_a->hash < he_b->hash)
    211 		ret = -1;
    212 	else {
    213 		if (he_a->minor_hash > he_b->minor_hash)
    214 			ret = 1;
    215 		else if (he_a->minor_hash < he_b->minor_hash)
    216 			ret = -1;
    217 		else
    218 			ret = name_cmp(a, b);
    219 	}
    220 	return ret;
    221 }
    222 
    223 static errcode_t alloc_size_dir(ext2_filsys fs, struct out_dir *outdir,
    224 				int blocks)
    225 {
    226 	void			*new_mem;
    227 
    228 	if (outdir->max) {
    229 		new_mem = realloc(outdir->buf, blocks * fs->blocksize);
    230 		if (!new_mem)
    231 			return ENOMEM;
    232 		outdir->buf = new_mem;
    233 		new_mem = realloc(outdir->hashes,
    234 				  blocks * sizeof(ext2_dirhash_t));
    235 		if (!new_mem)
    236 			return ENOMEM;
    237 		outdir->hashes = new_mem;
    238 	} else {
    239 		outdir->buf = malloc(blocks * fs->blocksize);
    240 		outdir->hashes = malloc(blocks * sizeof(ext2_dirhash_t));
    241 		outdir->num = 0;
    242 	}
    243 	outdir->max = blocks;
    244 	return 0;
    245 }
    246 
    247 static void free_out_dir(struct out_dir *outdir)
    248 {
    249 	free(outdir->buf);
    250 	free(outdir->hashes);
    251 	outdir->max = 0;
    252 	outdir->num =0;
    253 }
    254 
    255 static errcode_t get_next_block(ext2_filsys fs, struct out_dir *outdir,
    256 			 char ** ret)
    257 {
    258 	errcode_t	retval;
    259 
    260 	if (outdir->num >= outdir->max) {
    261 		retval = alloc_size_dir(fs, outdir, outdir->max + 50);
    262 		if (retval)
    263 			return retval;
    264 	}
    265 	*ret = outdir->buf + (outdir->num++ * fs->blocksize);
    266 	memset(*ret, 0, fs->blocksize);
    267 	return 0;
    268 }
    269 
    270 /*
    271  * This function is used to make a unique filename.  We do this by
    272  * appending ~0, and then incrementing the number.  However, we cannot
    273  * expand the length of the filename beyond the padding available in
    274  * the directory entry.
    275  */
    276 static void mutate_name(char *str, __u16 *len)
    277 {
    278 	int	i;
    279 	__u16	l = *len & 0xFF, h = *len & 0xff00;
    280 
    281 	/*
    282 	 * First check to see if it looks the name has been mutated
    283 	 * already
    284 	 */
    285 	for (i = l-1; i > 0; i--) {
    286 		if (!isdigit(str[i]))
    287 			break;
    288 	}
    289 	if ((i == l-1) || (str[i] != '~')) {
    290 		if (((l-1) & 3) < 2)
    291 			l += 2;
    292 		else
    293 			l = (l+3) & ~3;
    294 		str[l-2] = '~';
    295 		str[l-1] = '0';
    296 		*len = l | h;
    297 		return;
    298 	}
    299 	for (i = l-1; i >= 0; i--) {
    300 		if (isdigit(str[i])) {
    301 			if (str[i] == '9')
    302 				str[i] = '0';
    303 			else {
    304 				str[i]++;
    305 				return;
    306 			}
    307 			continue;
    308 		}
    309 		if (i == 1) {
    310 			if (str[0] == 'z')
    311 				str[0] = 'A';
    312 			else if (str[0] == 'Z') {
    313 				str[0] = '~';
    314 				str[1] = '0';
    315 			} else
    316 				str[0]++;
    317 		} else if (i > 0) {
    318 			str[i] = '1';
    319 			str[i-1] = '~';
    320 		} else {
    321 			if (str[0] == '~')
    322 				str[0] = 'a';
    323 			else
    324 				str[0]++;
    325 		}
    326 		break;
    327 	}
    328 }
    329 
    330 static int duplicate_search_and_fix(e2fsck_t ctx, ext2_filsys fs,
    331 				    ext2_ino_t ino,
    332 				    struct fill_dir_struct *fd)
    333 {
    334 	struct problem_context	pctx;
    335 	struct hash_entry 	*ent, *prev;
    336 	int			i, j;
    337 	int			fixed = 0;
    338 	char			new_name[256];
    339 	__u16			new_len;
    340 	int			hash_alg;
    341 
    342 	clear_problem_context(&pctx);
    343 	pctx.ino = ino;
    344 
    345 	hash_alg = fs->super->s_def_hash_version;
    346 	if ((hash_alg <= EXT2_HASH_TEA) &&
    347 	    (fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH))
    348 		hash_alg += 3;
    349 
    350 	for (i=1; i < fd->num_array; i++) {
    351 		ent = fd->harray + i;
    352 		prev = ent - 1;
    353 		if (!ent->dir->inode ||
    354 		    ((ent->dir->name_len & 0xFF) !=
    355 		     (prev->dir->name_len & 0xFF)) ||
    356 		    (strncmp(ent->dir->name, prev->dir->name,
    357 			     ent->dir->name_len & 0xFF)))
    358 			continue;
    359 		pctx.dirent = ent->dir;
    360 		if ((ent->dir->inode == prev->dir->inode) &&
    361 		    fix_problem(ctx, PR_2_DUPLICATE_DIRENT, &pctx)) {
    362 			e2fsck_adjust_inode_count(ctx, ent->dir->inode, -1);
    363 			ent->dir->inode = 0;
    364 			fixed++;
    365 			continue;
    366 		}
    367 		memcpy(new_name, ent->dir->name, ent->dir->name_len & 0xFF);
    368 		new_len = ent->dir->name_len;
    369 		mutate_name(new_name, &new_len);
    370 		for (j=0; j < fd->num_array; j++) {
    371 			if ((i==j) ||
    372 			    ((new_len & 0xFF) !=
    373 			     (fd->harray[j].dir->name_len & 0xFF)) ||
    374 			    (strncmp(new_name, fd->harray[j].dir->name,
    375 				     new_len & 0xFF)))
    376 				continue;
    377 			mutate_name(new_name, &new_len);
    378 
    379 			j = -1;
    380 		}
    381 		new_name[new_len & 0xFF] = 0;
    382 		pctx.str = new_name;
    383 		if (fix_problem(ctx, PR_2_NON_UNIQUE_FILE, &pctx)) {
    384 			memcpy(ent->dir->name, new_name, new_len & 0xFF);
    385 			ent->dir->name_len = new_len;
    386 			ext2fs_dirhash(hash_alg, ent->dir->name,
    387 				       ent->dir->name_len & 0xFF,
    388 				       fs->super->s_hash_seed,
    389 				       &ent->hash, &ent->minor_hash);
    390 			fixed++;
    391 		}
    392 	}
    393 	return fixed;
    394 }
    395 
    396 
    397 static errcode_t copy_dir_entries(e2fsck_t ctx,
    398 				  struct fill_dir_struct *fd,
    399 				  struct out_dir *outdir)
    400 {
    401 	ext2_filsys 		fs = ctx->fs;
    402 	errcode_t		retval;
    403 	char			*block_start;
    404 	struct hash_entry 	*ent;
    405 	struct ext2_dir_entry	*dirent;
    406 	unsigned int		rec_len, prev_rec_len, left, slack, offset;
    407 	int			i;
    408 	ext2_dirhash_t		prev_hash;
    409 
    410 	if (ctx->htree_slack_percentage == 255) {
    411 		profile_get_uint(ctx->profile, "options",
    412 				 "indexed_dir_slack_percentage",
    413 				 0, 20,
    414 				 &ctx->htree_slack_percentage);
    415 		if (ctx->htree_slack_percentage > 100)
    416 			ctx->htree_slack_percentage = 20;
    417 	}
    418 
    419 	outdir->max = 0;
    420 	retval = alloc_size_dir(fs, outdir,
    421 				(fd->dir_size / fs->blocksize) + 2);
    422 	if (retval)
    423 		return retval;
    424 	outdir->num = fd->compress ? 0 : 1;
    425 	offset = 0;
    426 	outdir->hashes[0] = 0;
    427 	prev_hash = 1;
    428 	if ((retval = get_next_block(fs, outdir, &block_start)))
    429 		return retval;
    430 	dirent = (struct ext2_dir_entry *) block_start;
    431 	prev_rec_len = 0;
    432 	rec_len = 0;
    433 	left = fs->blocksize;
    434 	slack = fd->compress ? 12 :
    435 		(fs->blocksize * ctx->htree_slack_percentage)/100;
    436 	if (slack < 12)
    437 		slack = 12;
    438 	for (i = 0; i < fd->num_array; i++) {
    439 		ent = fd->harray + i;
    440 		if (ent->dir->inode == 0)
    441 			continue;
    442 		rec_len = EXT2_DIR_REC_LEN(ent->dir->name_len & 0xFF);
    443 		if (rec_len > left) {
    444 			if (left) {
    445 				left += prev_rec_len;
    446 				retval = ext2fs_set_rec_len(fs, left, dirent);
    447 				if (retval)
    448 					return retval;
    449 			}
    450 			if ((retval = get_next_block(fs, outdir,
    451 						      &block_start)))
    452 				return retval;
    453 			offset = 0;
    454 		}
    455 		left = fs->blocksize - offset;
    456 		dirent = (struct ext2_dir_entry *) (block_start + offset);
    457 		if (offset == 0) {
    458 			if (ent->hash == prev_hash)
    459 				outdir->hashes[outdir->num-1] = ent->hash | 1;
    460 			else
    461 				outdir->hashes[outdir->num-1] = ent->hash;
    462 		}
    463 		dirent->inode = ent->dir->inode;
    464 		dirent->name_len = ent->dir->name_len;
    465 		retval = ext2fs_set_rec_len(fs, rec_len, dirent);
    466 		if (retval)
    467 			return retval;
    468 		prev_rec_len = rec_len;
    469 		memcpy(dirent->name, ent->dir->name, dirent->name_len & 0xFF);
    470 		offset += rec_len;
    471 		left -= rec_len;
    472 		if (left < slack) {
    473 			prev_rec_len += left;
    474 			retval = ext2fs_set_rec_len(fs, prev_rec_len, dirent);
    475 			if (retval)
    476 				return retval;
    477 			offset += left;
    478 			left = 0;
    479 		}
    480 		prev_hash = ent->hash;
    481 	}
    482 	if (left)
    483 		retval = ext2fs_set_rec_len(fs, rec_len + left, dirent);
    484 
    485 	return retval;
    486 }
    487 
    488 
    489 static struct ext2_dx_root_info *set_root_node(ext2_filsys fs, char *buf,
    490 				    ext2_ino_t ino, ext2_ino_t parent)
    491 {
    492 	struct ext2_dir_entry 		*dir;
    493 	struct ext2_dx_root_info  	*root;
    494 	struct ext2_dx_countlimit	*limits;
    495 	int				filetype = 0;
    496 
    497 	if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_FILETYPE)
    498 		filetype = EXT2_FT_DIR << 8;
    499 
    500 	memset(buf, 0, fs->blocksize);
    501 	dir = (struct ext2_dir_entry *) buf;
    502 	dir->inode = ino;
    503 	dir->name[0] = '.';
    504 	dir->name_len = 1 | filetype;
    505 	dir->rec_len = 12;
    506 	dir = (struct ext2_dir_entry *) (buf + 12);
    507 	dir->inode = parent;
    508 	dir->name[0] = '.';
    509 	dir->name[1] = '.';
    510 	dir->name_len = 2 | filetype;
    511 	dir->rec_len = fs->blocksize - 12;
    512 
    513 	root = (struct ext2_dx_root_info *) (buf+24);
    514 	root->reserved_zero = 0;
    515 	root->hash_version = fs->super->s_def_hash_version;
    516 	root->info_length = 8;
    517 	root->indirect_levels = 0;
    518 	root->unused_flags = 0;
    519 
    520 	limits = (struct ext2_dx_countlimit *) (buf+32);
    521 	limits->limit = (fs->blocksize - 32) / sizeof(struct ext2_dx_entry);
    522 	limits->count = 0;
    523 
    524 	return root;
    525 }
    526 
    527 
    528 static struct ext2_dx_entry *set_int_node(ext2_filsys fs, char *buf)
    529 {
    530 	struct ext2_dir_entry 		*dir;
    531 	struct ext2_dx_countlimit	*limits;
    532 
    533 	memset(buf, 0, fs->blocksize);
    534 	dir = (struct ext2_dir_entry *) buf;
    535 	dir->inode = 0;
    536 	(void) ext2fs_set_rec_len(fs, fs->blocksize, dir);
    537 
    538 	limits = (struct ext2_dx_countlimit *) (buf+8);
    539 	limits->limit = (fs->blocksize - 8) / sizeof(struct ext2_dx_entry);
    540 	limits->count = 0;
    541 
    542 	return (struct ext2_dx_entry *) limits;
    543 }
    544 
    545 /*
    546  * This function takes the leaf nodes which have been written in
    547  * outdir, and populates the root node and any necessary interior nodes.
    548  */
    549 static errcode_t calculate_tree(ext2_filsys fs,
    550 				struct out_dir *outdir,
    551 				ext2_ino_t ino,
    552 				ext2_ino_t parent)
    553 {
    554 	struct ext2_dx_root_info  	*root_info;
    555 	struct ext2_dx_entry 		*root, *dx_ent = 0;
    556 	struct ext2_dx_countlimit	*root_limit, *limit;
    557 	errcode_t			retval;
    558 	char				* block_start;
    559 	int				i, c1, c2, nblks;
    560 	int				limit_offset, root_offset;
    561 
    562 	root_info = set_root_node(fs, outdir->buf, ino, parent);
    563 	root_offset = limit_offset = ((char *) root_info - outdir->buf) +
    564 		root_info->info_length;
    565 	root_limit = (struct ext2_dx_countlimit *) (outdir->buf + limit_offset);
    566 	c1 = root_limit->limit;
    567 	nblks = outdir->num;
    568 
    569 	/* Write out the pointer blocks */
    570 	if (nblks-1 <= c1) {
    571 		/* Just write out the root block, and we're done */
    572 		root = (struct ext2_dx_entry *) (outdir->buf + root_offset);
    573 		for (i=1; i < nblks; i++) {
    574 			root->block = ext2fs_cpu_to_le32(i);
    575 			if (i != 1)
    576 				root->hash =
    577 					ext2fs_cpu_to_le32(outdir->hashes[i]);
    578 			root++;
    579 			c1--;
    580 		}
    581 	} else {
    582 		c2 = 0;
    583 		limit = 0;
    584 		root_info->indirect_levels = 1;
    585 		for (i=1; i < nblks; i++) {
    586 			if (c1 == 0)
    587 				return ENOSPC;
    588 			if (c2 == 0) {
    589 				if (limit)
    590 					limit->limit = limit->count =
    591 		ext2fs_cpu_to_le16(limit->limit);
    592 				root = (struct ext2_dx_entry *)
    593 					(outdir->buf + root_offset);
    594 				root->block = ext2fs_cpu_to_le32(outdir->num);
    595 				if (i != 1)
    596 					root->hash =
    597 			ext2fs_cpu_to_le32(outdir->hashes[i]);
    598 				if ((retval =  get_next_block(fs, outdir,
    599 							      &block_start)))
    600 					return retval;
    601 				dx_ent = set_int_node(fs, block_start);
    602 				limit = (struct ext2_dx_countlimit *) dx_ent;
    603 				c2 = limit->limit;
    604 				root_offset += sizeof(struct ext2_dx_entry);
    605 				c1--;
    606 			}
    607 			dx_ent->block = ext2fs_cpu_to_le32(i);
    608 			if (c2 != limit->limit)
    609 				dx_ent->hash =
    610 					ext2fs_cpu_to_le32(outdir->hashes[i]);
    611 			dx_ent++;
    612 			c2--;
    613 		}
    614 		limit->count = ext2fs_cpu_to_le16(limit->limit - c2);
    615 		limit->limit = ext2fs_cpu_to_le16(limit->limit);
    616 	}
    617 	root_limit = (struct ext2_dx_countlimit *) (outdir->buf + limit_offset);
    618 	root_limit->count = ext2fs_cpu_to_le16(root_limit->limit - c1);
    619 	root_limit->limit = ext2fs_cpu_to_le16(root_limit->limit);
    620 
    621 	return 0;
    622 }
    623 
    624 struct write_dir_struct {
    625 	struct out_dir *outdir;
    626 	errcode_t	err;
    627 	e2fsck_t	ctx;
    628 	blk64_t		cleared;
    629 };
    630 
    631 /*
    632  * Helper function which writes out a directory block.
    633  */
    634 static int write_dir_block(ext2_filsys fs,
    635 			   blk64_t *block_nr,
    636 			   e2_blkcnt_t blockcnt,
    637 			   blk64_t ref_block EXT2FS_ATTR((unused)),
    638 			   int ref_offset EXT2FS_ATTR((unused)),
    639 			   void *priv_data)
    640 {
    641 	struct write_dir_struct	*wd = (struct write_dir_struct *) priv_data;
    642 	blk64_t	blk;
    643 	char	*dir;
    644 
    645 	if (*block_nr == 0)
    646 		return 0;
    647 	if (blockcnt >= wd->outdir->num) {
    648 		e2fsck_read_bitmaps(wd->ctx);
    649 		blk = *block_nr;
    650 		/*
    651 		 * In theory, we only release blocks from the end of the
    652 		 * directory file, so it's fine to clobber a whole cluster at
    653 		 * once.
    654 		 */
    655 		if (blk % EXT2FS_CLUSTER_RATIO(fs) == 0) {
    656 			ext2fs_unmark_block_bitmap2(wd->ctx->block_found_map,
    657 						    blk);
    658 			ext2fs_block_alloc_stats2(fs, blk, -1);
    659 			wd->cleared++;
    660 		}
    661 		*block_nr = 0;
    662 		return BLOCK_CHANGED;
    663 	}
    664 	if (blockcnt < 0)
    665 		return 0;
    666 
    667 	dir = wd->outdir->buf + (blockcnt * fs->blocksize);
    668 	wd->err = ext2fs_write_dir_block3(fs, *block_nr, dir, 0);
    669 	if (wd->err)
    670 		return BLOCK_ABORT;
    671 	return 0;
    672 }
    673 
    674 static errcode_t write_directory(e2fsck_t ctx, ext2_filsys fs,
    675 				 struct out_dir *outdir,
    676 				 ext2_ino_t ino, int compress)
    677 {
    678 	struct write_dir_struct wd;
    679 	errcode_t	retval;
    680 	struct ext2_inode 	inode;
    681 
    682 	retval = e2fsck_expand_directory(ctx, ino, -1, outdir->num);
    683 	if (retval)
    684 		return retval;
    685 
    686 	wd.outdir = outdir;
    687 	wd.err = 0;
    688 	wd.ctx = ctx;
    689 	wd.cleared = 0;
    690 
    691 	retval = ext2fs_block_iterate3(fs, ino, 0, 0,
    692 				       write_dir_block, &wd);
    693 	if (retval)
    694 		return retval;
    695 	if (wd.err)
    696 		return wd.err;
    697 
    698 	e2fsck_read_inode(ctx, ino, &inode, "rehash_dir");
    699 	if (compress)
    700 		inode.i_flags &= ~EXT2_INDEX_FL;
    701 	else
    702 		inode.i_flags |= EXT2_INDEX_FL;
    703 	inode.i_size = outdir->num * fs->blocksize;
    704 	ext2fs_iblk_sub_blocks(fs, &inode, wd.cleared);
    705 	e2fsck_write_inode(ctx, ino, &inode, "rehash_dir");
    706 
    707 	return 0;
    708 }
    709 
    710 errcode_t e2fsck_rehash_dir(e2fsck_t ctx, ext2_ino_t ino)
    711 {
    712 	ext2_filsys 		fs = ctx->fs;
    713 	errcode_t		retval;
    714 	struct ext2_inode 	inode;
    715 	char			*dir_buf = 0;
    716 	struct fill_dir_struct	fd;
    717 	struct out_dir		outdir;
    718 
    719 	outdir.max = outdir.num = 0;
    720 	outdir.buf = 0;
    721 	outdir.hashes = 0;
    722 	e2fsck_read_inode(ctx, ino, &inode, "rehash_dir");
    723 
    724 	retval = ENOMEM;
    725 	fd.harray = 0;
    726 	dir_buf = malloc(inode.i_size);
    727 	if (!dir_buf)
    728 		goto errout;
    729 
    730 	fd.max_array = inode.i_size / 32;
    731 	fd.num_array = 0;
    732 	fd.harray = malloc(fd.max_array * sizeof(struct hash_entry));
    733 	if (!fd.harray)
    734 		goto errout;
    735 
    736 	fd.ctx = ctx;
    737 	fd.buf = dir_buf;
    738 	fd.inode = &inode;
    739 	fd.err = 0;
    740 	fd.dir_size = 0;
    741 	fd.compress = 0;
    742 	if (!(fs->super->s_feature_compat & EXT2_FEATURE_COMPAT_DIR_INDEX) ||
    743 	    (inode.i_size / fs->blocksize) < 2)
    744 		fd.compress = 1;
    745 	fd.parent = 0;
    746 
    747 retry_nohash:
    748 	/* Read in the entire directory into memory */
    749 	retval = ext2fs_block_iterate3(fs, ino, 0, 0,
    750 				       fill_dir_block, &fd);
    751 	if (fd.err) {
    752 		retval = fd.err;
    753 		goto errout;
    754 	}
    755 
    756 	/*
    757 	 * If the entries read are less than a block, then don't index
    758 	 * the directory
    759 	 */
    760 	if (!fd.compress && (fd.dir_size < (fs->blocksize - 24))) {
    761 		fd.compress = 1;
    762 		fd.dir_size = 0;
    763 		fd.num_array = 0;
    764 		goto retry_nohash;
    765 	}
    766 
    767 #if 0
    768 	printf("%d entries (%d bytes) found in inode %d\n",
    769 	       fd.num_array, fd.dir_size, ino);
    770 #endif
    771 
    772 	/* Sort the list */
    773 resort:
    774 	if (fd.compress)
    775 		qsort(fd.harray+2, fd.num_array-2, sizeof(struct hash_entry),
    776 		      hash_cmp);
    777 	else
    778 		qsort(fd.harray, fd.num_array, sizeof(struct hash_entry),
    779 		      hash_cmp);
    780 
    781 	/*
    782 	 * Look for duplicates
    783 	 */
    784 	if (duplicate_search_and_fix(ctx, fs, ino, &fd))
    785 		goto resort;
    786 
    787 	if (ctx->options & E2F_OPT_NO) {
    788 		retval = 0;
    789 		goto errout;
    790 	}
    791 
    792 	/* Sort non-hashed directories by inode number */
    793 	if (fd.compress)
    794 		qsort(fd.harray+2, fd.num_array-2,
    795 		      sizeof(struct hash_entry), ino_cmp);
    796 
    797 	/*
    798 	 * Copy the directory entries.  In a htree directory these
    799 	 * will become the leaf nodes.
    800 	 */
    801 	retval = copy_dir_entries(ctx, &fd, &outdir);
    802 	if (retval)
    803 		goto errout;
    804 
    805 	free(dir_buf); dir_buf = 0;
    806 
    807 	if (!fd.compress) {
    808 		/* Calculate the interior nodes */
    809 		retval = calculate_tree(fs, &outdir, ino, fd.parent);
    810 		if (retval)
    811 			goto errout;
    812 	}
    813 
    814 	retval = write_directory(ctx, fs, &outdir, ino, fd.compress);
    815 	if (retval)
    816 		goto errout;
    817 
    818 errout:
    819 	free(dir_buf);
    820 	free(fd.harray);
    821 
    822 	free_out_dir(&outdir);
    823 	return retval;
    824 }
    825 
    826 void e2fsck_rehash_directories(e2fsck_t ctx)
    827 {
    828 	struct problem_context	pctx;
    829 #ifdef RESOURCE_TRACK
    830 	struct resource_track	rtrack;
    831 #endif
    832 	struct dir_info		*dir;
    833 	ext2_u32_iterate 	iter;
    834 	struct dir_info_iter *	dirinfo_iter = 0;
    835 	ext2_ino_t		ino;
    836 	errcode_t		retval;
    837 	int			cur, max, all_dirs, first = 1;
    838 
    839 	init_resource_track(&rtrack, ctx->fs->io);
    840 	all_dirs = ctx->options & E2F_OPT_COMPRESS_DIRS;
    841 
    842 	if (!ctx->dirs_to_hash && !all_dirs)
    843 		return;
    844 
    845 	e2fsck_get_lost_and_found(ctx, 0);
    846 
    847 	clear_problem_context(&pctx);
    848 
    849 	cur = 0;
    850 	if (all_dirs) {
    851 		dirinfo_iter = e2fsck_dir_info_iter_begin(ctx);
    852 		max = e2fsck_get_num_dirinfo(ctx);
    853 	} else {
    854 		retval = ext2fs_u32_list_iterate_begin(ctx->dirs_to_hash,
    855 						       &iter);
    856 		if (retval) {
    857 			pctx.errcode = retval;
    858 			fix_problem(ctx, PR_3A_OPTIMIZE_ITER, &pctx);
    859 			return;
    860 		}
    861 		max = ext2fs_u32_list_count(ctx->dirs_to_hash);
    862 	}
    863 	while (1) {
    864 		if (all_dirs) {
    865 			if ((dir = e2fsck_dir_info_iter(ctx,
    866 							dirinfo_iter)) == 0)
    867 				break;
    868 			ino = dir->ino;
    869 		} else {
    870 			if (!ext2fs_u32_list_iterate(iter, &ino))
    871 				break;
    872 		}
    873 		if (ino == ctx->lost_and_found)
    874 			continue;
    875 		pctx.dir = ino;
    876 		if (first) {
    877 			fix_problem(ctx, PR_3A_PASS_HEADER, &pctx);
    878 			first = 0;
    879 		}
    880 #if 0
    881 		fix_problem(ctx, PR_3A_OPTIMIZE_DIR, &pctx);
    882 #endif
    883 		pctx.errcode = e2fsck_rehash_dir(ctx, ino);
    884 		if (pctx.errcode) {
    885 			end_problem_latch(ctx, PR_LATCH_OPTIMIZE_DIR);
    886 			fix_problem(ctx, PR_3A_OPTIMIZE_DIR_ERR, &pctx);
    887 		}
    888 		if (ctx->progress && !ctx->progress_fd)
    889 			e2fsck_simple_progress(ctx, "Rebuilding directory",
    890 			       100.0 * (float) (++cur) / (float) max, ino);
    891 	}
    892 	end_problem_latch(ctx, PR_LATCH_OPTIMIZE_DIR);
    893 	if (all_dirs)
    894 		e2fsck_dir_info_iter_end(ctx, dirinfo_iter);
    895 	else
    896 		ext2fs_u32_list_iterate_end(iter);
    897 
    898 	if (ctx->dirs_to_hash)
    899 		ext2fs_u32_list_free(ctx->dirs_to_hash);
    900 	ctx->dirs_to_hash = 0;
    901 
    902 	print_resource_track(ctx, "Pass 3A", &rtrack, ctx->fs->io);
    903 }
    904