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      1 /*
      2  * dirinfo.c --- maintains the directory information table for e2fsck.
      3  *
      4  * Copyright (C) 1993 Theodore Ts'o.  This file may be redistributed
      5  * under the terms of the GNU Public License.
      6  */
      7 
      8 #undef DIRINFO_DEBUG
      9 
     10 #include "config.h"
     11 #include "e2fsck.h"
     12 #include <sys/stat.h>
     13 #include <fcntl.h>
     14 #include "uuid/uuid.h"
     15 
     16 #include "ext2fs/ext2fs.h"
     17 #include <ext2fs/tdb.h>
     18 
     19 struct dir_info_db {
     20 	int		count;
     21 	int		size;
     22 	struct dir_info *array;
     23 	struct dir_info *last_lookup;
     24 #ifdef CONFIG_TDB
     25 	char		*tdb_fn;
     26 	TDB_CONTEXT	*tdb;
     27 #endif
     28 };
     29 
     30 struct dir_info_iter {
     31 	int	i;
     32 #ifdef CONFIG_TDB
     33 	TDB_DATA	tdb_iter;
     34 #endif
     35 };
     36 
     37 struct dir_info_ent {
     38 	ext2_ino_t		dotdot;	/* Parent according to '..' */
     39 	ext2_ino_t		parent; /* Parent according to treewalk */
     40 };
     41 
     42 
     43 static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir);
     44 
     45 #ifdef CONFIG_TDB
     46 static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
     47 {
     48 	struct dir_info_db	*db = ctx->dir_info;
     49 	unsigned int		threshold;
     50 	errcode_t		retval;
     51 	mode_t			save_umask;
     52 	char			*tdb_dir, uuid[40];
     53 	int			fd, enable;
     54 
     55 	profile_get_string(ctx->profile, "scratch_files", "directory", 0, 0,
     56 			   &tdb_dir);
     57 	profile_get_uint(ctx->profile, "scratch_files",
     58 			 "numdirs_threshold", 0, 0, &threshold);
     59 	profile_get_boolean(ctx->profile, "scratch_files",
     60 			    "dirinfo", 0, 1, &enable);
     61 
     62 	if (!enable || !tdb_dir || access(tdb_dir, W_OK) ||
     63 	    (threshold && num_dirs <= threshold))
     64 		return;
     65 
     66 	retval = ext2fs_get_mem(strlen(tdb_dir) + 64, &db->tdb_fn);
     67 	if (retval)
     68 		return;
     69 
     70 	uuid_unparse(ctx->fs->super->s_uuid, uuid);
     71 	sprintf(db->tdb_fn, "%s/%s-dirinfo-XXXXXX", tdb_dir, uuid);
     72 	save_umask = umask(077);
     73 	fd = mkstemp(db->tdb_fn);
     74 	umask(save_umask);
     75 	if (fd < 0) {
     76 		db->tdb = NULL;
     77 		return;
     78 	}
     79 
     80 	if (num_dirs < 99991)
     81 		num_dirs = 99991; /* largest 5 digit prime */
     82 
     83 	db->tdb = tdb_open(db->tdb_fn, num_dirs, TDB_NOLOCK | TDB_NOSYNC,
     84 			   O_RDWR | O_CREAT | O_TRUNC, 0600);
     85 	close(fd);
     86 }
     87 #endif
     88 
     89 static void setup_db(e2fsck_t ctx)
     90 {
     91 	struct dir_info_db	*db;
     92 	ext2_ino_t		num_dirs;
     93 	errcode_t		retval;
     94 
     95 	db = (struct dir_info_db *)
     96 		e2fsck_allocate_memory(ctx, sizeof(struct dir_info_db),
     97 				       "directory map db");
     98 	db->count = db->size = 0;
     99 	db->array = 0;
    100 
    101 	ctx->dir_info = db;
    102 
    103 	retval = ext2fs_get_num_dirs(ctx->fs, &num_dirs);
    104 	if (retval)
    105 		num_dirs = 1024;	/* Guess */
    106 
    107 #ifdef CONFIG_TDB
    108 	setup_tdb(ctx, num_dirs);
    109 
    110 	if (db->tdb) {
    111 #ifdef DIRINFO_DEBUG
    112 		printf("Note: using tdb!\n");
    113 #endif
    114 		return;
    115 	}
    116 #endif
    117 
    118 	db->size = num_dirs + 10;
    119 	db->array  = (struct dir_info *)
    120 		e2fsck_allocate_memory(ctx, db->size
    121 				       * sizeof (struct dir_info),
    122 				       "directory map");
    123 }
    124 
    125 /*
    126  * This subroutine is called during pass1 to create a directory info
    127  * entry.  During pass1, the passed-in parent is 0; it will get filled
    128  * in during pass2.
    129  */
    130 void e2fsck_add_dir_info(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
    131 {
    132 	struct dir_info		*dir, *old_array;
    133 	int			i, j;
    134 	errcode_t		retval;
    135 	unsigned long		old_size;
    136 
    137 #ifdef DIRINFO_DEBUG
    138 	printf("add_dir_info for inode (%lu, %lu)...\n", ino, parent);
    139 #endif
    140 	if (!ctx->dir_info)
    141 		setup_db(ctx);
    142 
    143 	if (ctx->dir_info->count >= ctx->dir_info->size) {
    144 		old_size = ctx->dir_info->size * sizeof(struct dir_info);
    145 		ctx->dir_info->size += 10;
    146 		old_array = ctx->dir_info->array;
    147 		retval = ext2fs_resize_mem(old_size, ctx->dir_info->size *
    148 					   sizeof(struct dir_info),
    149 					   &ctx->dir_info->array);
    150 		if (retval) {
    151 			fprintf(stderr, "Couldn't reallocate dir_info "
    152 				"structure to %d entries\n",
    153 				ctx->dir_info->size);
    154 			fatal_error(ctx, 0);
    155 			ctx->dir_info->size -= 10;
    156 			return;
    157 		}
    158 		if (old_array != ctx->dir_info->array)
    159 			ctx->dir_info->last_lookup = NULL;
    160 	}
    161 
    162 #ifdef CONFIG_TDB
    163 	if (ctx->dir_info->tdb) {
    164 		struct dir_info ent;
    165 
    166 		ent.ino = ino;
    167 		ent.parent = parent;
    168 		ent.dotdot = parent;
    169 		e2fsck_put_dir_info(ctx, &ent);
    170 		return;
    171 	}
    172 #endif
    173 
    174 	/*
    175 	 * Normally, add_dir_info is called with each inode in
    176 	 * sequential order; but once in a while (like when pass 3
    177 	 * needs to recreate the root directory or lost+found
    178 	 * directory) it is called out of order.  In those cases, we
    179 	 * need to move the dir_info entries down to make room, since
    180 	 * the dir_info array needs to be sorted by inode number for
    181 	 * get_dir_info()'s sake.
    182 	 */
    183 	if (ctx->dir_info->count &&
    184 	    ctx->dir_info->array[ctx->dir_info->count-1].ino >= ino) {
    185 		for (i = ctx->dir_info->count-1; i > 0; i--)
    186 			if (ctx->dir_info->array[i-1].ino < ino)
    187 				break;
    188 		dir = &ctx->dir_info->array[i];
    189 		if (dir->ino != ino)
    190 			for (j = ctx->dir_info->count++; j > i; j--)
    191 				ctx->dir_info->array[j] = ctx->dir_info->array[j-1];
    192 	} else
    193 		dir = &ctx->dir_info->array[ctx->dir_info->count++];
    194 
    195 	dir->ino = ino;
    196 	dir->dotdot = parent;
    197 	dir->parent = parent;
    198 }
    199 
    200 /*
    201  * get_dir_info() --- given an inode number, try to find the directory
    202  * information entry for it.
    203  */
    204 static struct dir_info *e2fsck_get_dir_info(e2fsck_t ctx, ext2_ino_t ino)
    205 {
    206 	struct dir_info_db	*db = ctx->dir_info;
    207 	int			low, high, mid;
    208 
    209 	if (!db)
    210 		return 0;
    211 
    212 #ifdef DIRINFO_DEBUG
    213 	printf("e2fsck_get_dir_info %d...", ino);
    214 #endif
    215 
    216 #ifdef CONFIG_TDB
    217 	if (db->tdb) {
    218 		static struct dir_info	ret_dir_info;
    219 		TDB_DATA key, data;
    220 		struct dir_info_ent	*buf;
    221 
    222 		key.dptr = (unsigned char *) &ino;
    223 		key.dsize = sizeof(ext2_ino_t);
    224 
    225 		data = tdb_fetch(db->tdb, key);
    226 		if (!data.dptr) {
    227 			if (tdb_error(db->tdb) != TDB_ERR_NOEXIST)
    228 				printf("fetch failed: %s\n",
    229 				       tdb_errorstr(db->tdb));
    230 			return 0;
    231 		}
    232 
    233 		buf = (struct dir_info_ent *) data.dptr;
    234 		ret_dir_info.ino = ino;
    235 		ret_dir_info.dotdot = buf->dotdot;
    236 		ret_dir_info.parent = buf->parent;
    237 #ifdef DIRINFO_DEBUG
    238 		printf("(%d,%d,%d)\n", ino, buf->dotdot, buf->parent);
    239 #endif
    240 		free(data.dptr);
    241 		return &ret_dir_info;
    242 	}
    243 #endif
    244 
    245 	if (db->last_lookup && db->last_lookup->ino == ino)
    246 		return db->last_lookup;
    247 
    248 	low = 0;
    249 	high = ctx->dir_info->count-1;
    250 	if (ino == ctx->dir_info->array[low].ino) {
    251 #ifdef DIRINFO_DEBUG
    252 		printf("(%d,%d,%d)\n", ino,
    253 		       ctx->dir_info->array[low].dotdot,
    254 		       ctx->dir_info->array[low].parent);
    255 #endif
    256 		return &ctx->dir_info->array[low];
    257 	}
    258 	if (ino == ctx->dir_info->array[high].ino) {
    259 #ifdef DIRINFO_DEBUG
    260 		printf("(%d,%d,%d)\n", ino,
    261 		       ctx->dir_info->array[high].dotdot,
    262 		       ctx->dir_info->array[high].parent);
    263 #endif
    264 		return &ctx->dir_info->array[high];
    265 	}
    266 
    267 	while (low < high) {
    268 		mid = (low+high)/2;
    269 		if (mid == low || mid == high)
    270 			break;
    271 		if (ino == ctx->dir_info->array[mid].ino) {
    272 #ifdef DIRINFO_DEBUG
    273 			printf("(%d,%d,%d)\n", ino,
    274 			       ctx->dir_info->array[mid].dotdot,
    275 			       ctx->dir_info->array[mid].parent);
    276 #endif
    277 			return &ctx->dir_info->array[mid];
    278 		}
    279 		if (ino < ctx->dir_info->array[mid].ino)
    280 			high = mid;
    281 		else
    282 			low = mid;
    283 	}
    284 	return 0;
    285 }
    286 
    287 static void e2fsck_put_dir_info(e2fsck_t ctx EXT2FS_NO_TDB_UNUSED,
    288 				struct dir_info *dir EXT2FS_NO_TDB_UNUSED)
    289 {
    290 #ifdef CONFIG_TDB
    291 	struct dir_info_db	*db = ctx->dir_info;
    292 	struct dir_info_ent	buf;
    293 	TDB_DATA		key, data;
    294 #endif
    295 
    296 #ifdef DIRINFO_DEBUG
    297 	printf("e2fsck_put_dir_info (%d, %d, %d)...", dir->ino, dir->dotdot,
    298 	       dir->parent);
    299 #endif
    300 
    301 #ifdef CONFIG_TDB
    302 	if (!db->tdb)
    303 		return;
    304 
    305 	buf.parent = dir->parent;
    306 	buf.dotdot = dir->dotdot;
    307 
    308 	key.dptr = (unsigned char *) &dir->ino;
    309 	key.dsize = sizeof(ext2_ino_t);
    310 	data.dptr = (unsigned char *) &buf;
    311 	data.dsize = sizeof(buf);
    312 
    313 	if (tdb_store(db->tdb, key, data, TDB_REPLACE) == -1) {
    314 		printf("store failed: %s\n", tdb_errorstr(db->tdb));
    315 	}
    316 #endif
    317 }
    318 
    319 /*
    320  * Free the dir_info structure when it isn't needed any more.
    321  */
    322 void e2fsck_free_dir_info(e2fsck_t ctx)
    323 {
    324 	if (ctx->dir_info) {
    325 #ifdef CONFIG_TDB
    326 		if (ctx->dir_info->tdb)
    327 			tdb_close(ctx->dir_info->tdb);
    328 		if (ctx->dir_info->tdb_fn) {
    329 			if (unlink(ctx->dir_info->tdb_fn) < 0)
    330 				com_err("e2fsck_free_dir_info", errno,
    331 					_("while freeing dir_info tdb file"));
    332 			free(ctx->dir_info->tdb_fn);
    333 		}
    334 #endif
    335 		if (ctx->dir_info->array)
    336 			ext2fs_free_mem(&ctx->dir_info->array);
    337 		ctx->dir_info->array = 0;
    338 		ctx->dir_info->size = 0;
    339 		ctx->dir_info->count = 0;
    340 		ext2fs_free_mem(&ctx->dir_info);
    341 		ctx->dir_info = 0;
    342 	}
    343 }
    344 
    345 /*
    346  * Return the count of number of directories in the dir_info structure
    347  */
    348 int e2fsck_get_num_dirinfo(e2fsck_t ctx)
    349 {
    350 	return ctx->dir_info ? ctx->dir_info->count : 0;
    351 }
    352 
    353 struct dir_info_iter *e2fsck_dir_info_iter_begin(e2fsck_t ctx)
    354 {
    355 	struct dir_info_iter *iter;
    356 
    357 	iter = e2fsck_allocate_memory(ctx, sizeof(struct dir_info_iter),
    358 				      "dir_info iterator");
    359 
    360 #ifdef CONFIG_TDB
    361 	if (ctx->dir_info->tdb)
    362 		iter->tdb_iter = tdb_firstkey(ctx->dir_info->tdb);
    363 #endif
    364 
    365 	return iter;
    366 }
    367 
    368 void e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR((unused)),
    369 			      struct dir_info_iter *iter)
    370 {
    371 #ifdef CONFIG_TDB
    372 	free(iter->tdb_iter.dptr);
    373 #endif
    374 	ext2fs_free_mem(&iter);
    375 }
    376 
    377 /*
    378  * A simple interator function
    379  */
    380 struct dir_info *e2fsck_dir_info_iter(e2fsck_t ctx, struct dir_info_iter *iter)
    381 {
    382 	if (!ctx->dir_info || !iter)
    383 		return 0;
    384 
    385 #ifdef CONFIG_TDB
    386 	if (ctx->dir_info->tdb) {
    387 		static struct dir_info ret_dir_info;
    388 		struct dir_info_ent *buf;
    389 		TDB_DATA data, key;
    390 
    391 		if (iter->tdb_iter.dptr == 0)
    392 			return 0;
    393 		key = iter->tdb_iter;
    394 		data = tdb_fetch(ctx->dir_info->tdb, key);
    395 		if (!data.dptr) {
    396 			printf("iter fetch failed: %s\n",
    397 			       tdb_errorstr(ctx->dir_info->tdb));
    398 			return 0;
    399 		}
    400 		buf = (struct dir_info_ent *) data.dptr;
    401 		ret_dir_info.ino = *((ext2_ino_t *) iter->tdb_iter.dptr);
    402 		ret_dir_info.dotdot = buf->dotdot;
    403 		ret_dir_info.parent = buf->parent;
    404 		iter->tdb_iter = tdb_nextkey(ctx->dir_info->tdb, key);
    405 		free(key.dptr);
    406 		free(data.dptr);
    407 		return &ret_dir_info;
    408 	}
    409 #endif
    410 
    411 	if (iter->i >= ctx->dir_info->count)
    412 		return 0;
    413 
    414 #ifdef DIRINFO_DEBUG
    415 	printf("iter(%d, %d, %d)...", ctx->dir_info->array[iter->i].ino,
    416 	       ctx->dir_info->array[iter->i].dotdot,
    417 	       ctx->dir_info->array[iter->i].parent);
    418 #endif
    419 	ctx->dir_info->last_lookup = ctx->dir_info->array + iter->i++;
    420 	return(ctx->dir_info->last_lookup);
    421 }
    422 
    423 /*
    424  * This function only sets the parent pointer, and requires that
    425  * dirinfo structure has already been created.
    426  */
    427 int e2fsck_dir_info_set_parent(e2fsck_t ctx, ext2_ino_t ino,
    428 			       ext2_ino_t parent)
    429 {
    430 	struct dir_info *p;
    431 
    432 	p = e2fsck_get_dir_info(ctx, ino);
    433 	if (!p)
    434 		return 1;
    435 	p->parent = parent;
    436 	e2fsck_put_dir_info(ctx, p);
    437 	return 0;
    438 }
    439 
    440 /*
    441  * This function only sets the dot dot pointer, and requires that
    442  * dirinfo structure has already been created.
    443  */
    444 int e2fsck_dir_info_set_dotdot(e2fsck_t ctx, ext2_ino_t ino,
    445 			       ext2_ino_t dotdot)
    446 {
    447 	struct dir_info *p;
    448 
    449 	p = e2fsck_get_dir_info(ctx, ino);
    450 	if (!p)
    451 		return 1;
    452 	p->dotdot = dotdot;
    453 	e2fsck_put_dir_info(ctx, p);
    454 	return 0;
    455 }
    456 
    457 /*
    458  * This function only sets the parent pointer, and requires that
    459  * dirinfo structure has already been created.
    460  */
    461 int e2fsck_dir_info_get_parent(e2fsck_t ctx, ext2_ino_t ino,
    462 			       ext2_ino_t *parent)
    463 {
    464 	struct dir_info *p;
    465 
    466 	p = e2fsck_get_dir_info(ctx, ino);
    467 	if (!p)
    468 		return 1;
    469 	*parent = p->parent;
    470 	return 0;
    471 }
    472 
    473 /*
    474  * This function only sets the dot dot pointer, and requires that
    475  * dirinfo structure has already been created.
    476  */
    477 int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
    478 			       ext2_ino_t *dotdot)
    479 {
    480 	struct dir_info *p;
    481 
    482 	p = e2fsck_get_dir_info(ctx, ino);
    483 	if (!p)
    484 		return 1;
    485 	*dotdot = p->dotdot;
    486 	return 0;
    487 }
    488 
    489