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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
setup_tdb(e2fsck_t ctx,ext2_ino_t num_dirs)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 
setup_db(e2fsck_t ctx)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  */
e2fsck_add_dir_info(e2fsck_t ctx,ext2_ino_t ino,ext2_ino_t parent)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  */
e2fsck_get_dir_info(e2fsck_t ctx,ext2_ino_t ino)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 
e2fsck_put_dir_info(e2fsck_t ctx EXT2FS_NO_TDB_UNUSED,struct dir_info * dir EXT2FS_NO_TDB_UNUSED)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  */
e2fsck_free_dir_info(e2fsck_t ctx)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 			unlink(ctx->dir_info->tdb_fn);
330 			free(ctx->dir_info->tdb_fn);
331 		}
332 #endif
333 		if (ctx->dir_info->array)
334 			ext2fs_free_mem(&ctx->dir_info->array);
335 		ctx->dir_info->array = 0;
336 		ctx->dir_info->size = 0;
337 		ctx->dir_info->count = 0;
338 		ext2fs_free_mem(&ctx->dir_info);
339 		ctx->dir_info = 0;
340 	}
341 }
342 
343 /*
344  * Return the count of number of directories in the dir_info structure
345  */
e2fsck_get_num_dirinfo(e2fsck_t ctx)346 int e2fsck_get_num_dirinfo(e2fsck_t ctx)
347 {
348 	return ctx->dir_info ? ctx->dir_info->count : 0;
349 }
350 
e2fsck_dir_info_iter_begin(e2fsck_t ctx)351 struct dir_info_iter *e2fsck_dir_info_iter_begin(e2fsck_t ctx)
352 {
353 	struct dir_info_iter *iter;
354 
355 	iter = e2fsck_allocate_memory(ctx, sizeof(struct dir_info_iter),
356 				      "dir_info iterator");
357 
358 #ifdef CONFIG_TDB
359 	if (ctx->dir_info->tdb)
360 		iter->tdb_iter = tdb_firstkey(ctx->dir_info->tdb);
361 #endif
362 
363 	return iter;
364 }
365 
e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR ((unused)),struct dir_info_iter * iter)366 void e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR((unused)),
367 			      struct dir_info_iter *iter)
368 {
369 #ifdef CONFIG_TDB
370 	free(iter->tdb_iter.dptr);
371 #endif
372 	ext2fs_free_mem(&iter);
373 }
374 
375 /*
376  * A simple interator function
377  */
e2fsck_dir_info_iter(e2fsck_t ctx,struct dir_info_iter * iter)378 struct dir_info *e2fsck_dir_info_iter(e2fsck_t ctx, struct dir_info_iter *iter)
379 {
380 	if (!ctx->dir_info || !iter)
381 		return 0;
382 
383 #ifdef CONFIG_TDB
384 	if (ctx->dir_info->tdb) {
385 		static struct dir_info ret_dir_info;
386 		struct dir_info_ent *buf;
387 		TDB_DATA data, key;
388 
389 		if (iter->tdb_iter.dptr == 0)
390 			return 0;
391 		key = iter->tdb_iter;
392 		data = tdb_fetch(ctx->dir_info->tdb, key);
393 		if (!data.dptr) {
394 			printf("iter fetch failed: %s\n",
395 			       tdb_errorstr(ctx->dir_info->tdb));
396 			return 0;
397 		}
398 		buf = (struct dir_info_ent *) data.dptr;
399 		ret_dir_info.ino = *((ext2_ino_t *) iter->tdb_iter.dptr);
400 		ret_dir_info.dotdot = buf->dotdot;
401 		ret_dir_info.parent = buf->parent;
402 		iter->tdb_iter = tdb_nextkey(ctx->dir_info->tdb, key);
403 		free(key.dptr);
404 		free(data.dptr);
405 		return &ret_dir_info;
406 	}
407 #endif
408 
409 	if (iter->i >= ctx->dir_info->count)
410 		return 0;
411 
412 #ifdef DIRINFO_DEBUG
413 	printf("iter(%d, %d, %d)...", ctx->dir_info->array[iter->i].ino,
414 	       ctx->dir_info->array[iter->i].dotdot,
415 	       ctx->dir_info->array[iter->i].parent);
416 #endif
417 	ctx->dir_info->last_lookup = ctx->dir_info->array + iter->i++;
418 	return(ctx->dir_info->last_lookup);
419 }
420 
421 /*
422  * This function only sets the parent pointer, and requires that
423  * dirinfo structure has already been created.
424  */
e2fsck_dir_info_set_parent(e2fsck_t ctx,ext2_ino_t ino,ext2_ino_t parent)425 int e2fsck_dir_info_set_parent(e2fsck_t ctx, ext2_ino_t ino,
426 			       ext2_ino_t parent)
427 {
428 	struct dir_info *p;
429 
430 	p = e2fsck_get_dir_info(ctx, ino);
431 	if (!p)
432 		return 1;
433 	p->parent = parent;
434 	e2fsck_put_dir_info(ctx, p);
435 	return 0;
436 }
437 
438 /*
439  * This function only sets the dot dot pointer, and requires that
440  * dirinfo structure has already been created.
441  */
e2fsck_dir_info_set_dotdot(e2fsck_t ctx,ext2_ino_t ino,ext2_ino_t dotdot)442 int e2fsck_dir_info_set_dotdot(e2fsck_t ctx, ext2_ino_t ino,
443 			       ext2_ino_t dotdot)
444 {
445 	struct dir_info *p;
446 
447 	p = e2fsck_get_dir_info(ctx, ino);
448 	if (!p)
449 		return 1;
450 	p->dotdot = dotdot;
451 	e2fsck_put_dir_info(ctx, p);
452 	return 0;
453 }
454 
455 /*
456  * This function only sets the parent pointer, and requires that
457  * dirinfo structure has already been created.
458  */
e2fsck_dir_info_get_parent(e2fsck_t ctx,ext2_ino_t ino,ext2_ino_t * parent)459 int e2fsck_dir_info_get_parent(e2fsck_t ctx, ext2_ino_t ino,
460 			       ext2_ino_t *parent)
461 {
462 	struct dir_info *p;
463 
464 	p = e2fsck_get_dir_info(ctx, ino);
465 	if (!p)
466 		return 1;
467 	*parent = p->parent;
468 	return 0;
469 }
470 
471 /*
472  * This function only sets the dot dot pointer, and requires that
473  * dirinfo structure has already been created.
474  */
e2fsck_dir_info_get_dotdot(e2fsck_t ctx,ext2_ino_t ino,ext2_ino_t * dotdot)475 int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
476 			       ext2_ino_t *dotdot)
477 {
478 	struct dir_info *p;
479 
480 	p = e2fsck_get_dir_info(ctx, ino);
481 	if (!p)
482 		return 1;
483 	*dotdot = p->dotdot;
484 	return 0;
485 }
486 
487