dirinfo.c revision f404167dda29a59d2be2882328aeb074b9899669 
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/tdb.h>
17
18struct dir_info_db {
19	int		count;
20	int		size;
21	struct dir_info *array;
22	struct dir_info *last_lookup;
23	char		*tdb_fn;
24	TDB_CONTEXT	*tdb;
25};
26
27struct dir_info_iter {
28	int	i;
29	TDB_DATA	tdb_iter;
30};
31
32struct dir_info_ent {
33	ext2_ino_t		dotdot;	/* Parent according to '..' */
34	ext2_ino_t		parent; /* Parent according to treewalk */
35};
36
37
38static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir);
39
40static void setup_tdb(e2fsck_t ctx, ext2_ino_t num_dirs)
41{
42	struct dir_info_db	*db = ctx->dir_info;
43	unsigned int		threshold;
44	errcode_t		retval;
45	char			*tdb_dir, uuid[40];
46	int			fd, enable;
47
48	profile_get_string(ctx->profile, "scratch_files", "directory", 0, 0,
49			   &tdb_dir);
50	profile_get_uint(ctx->profile, "scratch_files",
51			 "numdirs_threshold", 0, 0, &threshold);
52	profile_get_boolean(ctx->profile, "scratch_files",
53			    "dirinfo", 0, 1, &enable);
54
55	if (!enable || !tdb_dir || access(tdb_dir, W_OK) ||
56	    (threshold && num_dirs <= threshold))
57		return;
58
59	retval = ext2fs_get_mem(strlen(tdb_dir) + 64, &db->tdb_fn);
60	if (retval)
61		return;
62
63	uuid_unparse(ctx->fs->super->s_uuid, uuid);
64	sprintf(db->tdb_fn, "%s/%s-dirinfo-XXXXXX", tdb_dir, uuid);
65	fd = mkstemp(db->tdb_fn);
66	if (fd < 0) {
67		db->tdb = NULL;
68		return;
69	}
70
71	if (num_dirs < 99991)
72		num_dirs = 99991; /* largest 5 digit prime */
73
74	db->tdb = tdb_open(db->tdb_fn, num_dirs, TDB_NOLOCK | TDB_NOSYNC,
75			   O_RDWR | O_CREAT | O_TRUNC, 0600);
76	close(fd);
77}
78
79static void setup_db(e2fsck_t ctx)
80{
81	struct dir_info_db	*db;
82	ext2_ino_t		num_dirs;
83	errcode_t		retval;
84
85	db = (struct dir_info_db *)
86		e2fsck_allocate_memory(ctx, sizeof(struct dir_info_db),
87				       "directory map db");
88	db->count = db->size = 0;
89	db->array = 0;
90
91	ctx->dir_info = db;
92
93	retval = ext2fs_get_num_dirs(ctx->fs, &num_dirs);
94	if (retval)
95		num_dirs = 1024;	/* Guess */
96
97	setup_tdb(ctx, num_dirs);
98
99	if (db->tdb) {
100#ifdef DIRINFO_DEBUG
101		printf("Note: using tdb!\n");
102#endif
103		return;
104	}
105
106	db->size = num_dirs + 10;
107	db->array  = (struct dir_info *)
108		e2fsck_allocate_memory(ctx, db->size
109				       * sizeof (struct dir_info),
110				       "directory map");
111}
112
113/*
114 * This subroutine is called during pass1 to create a directory info
115 * entry.  During pass1, the passed-in parent is 0; it will get filled
116 * in during pass2.
117 */
118void e2fsck_add_dir_info(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
119{
120	struct dir_info_db 	*db;
121	struct dir_info 	*dir, ent;
122	int			i, j;
123	errcode_t		retval;
124	unsigned long		old_size;
125
126#ifdef DIRINFO_DEBUG
127	printf("add_dir_info for inode (%lu, %lu)...\n", ino, parent);
128#endif
129	if (!ctx->dir_info)
130		setup_db(ctx);
131	db = ctx->dir_info;
132
133	if (ctx->dir_info->count >= ctx->dir_info->size) {
134		old_size = ctx->dir_info->size * sizeof(struct dir_info);
135		ctx->dir_info->size += 10;
136		retval = ext2fs_resize_mem(old_size, ctx->dir_info->size *
137					   sizeof(struct dir_info),
138					   &ctx->dir_info->array);
139		if (retval) {
140			ctx->dir_info->size -= 10;
141			return;
142		}
143	}
144
145	ent.ino = ino;
146	ent.parent = parent;
147	ent.dotdot = parent;
148
149	if (db->tdb) {
150		e2fsck_put_dir_info(ctx, &ent);
151		return;
152	}
153
154	/*
155	 * Normally, add_dir_info is called with each inode in
156	 * sequential order; but once in a while (like when pass 3
157	 * needs to recreate the root directory or lost+found
158	 * directory) it is called out of order.  In those cases, we
159	 * need to move the dir_info entries down to make room, since
160	 * the dir_info array needs to be sorted by inode number for
161	 * get_dir_info()'s sake.
162	 */
163	if (ctx->dir_info->count &&
164	    ctx->dir_info->array[ctx->dir_info->count-1].ino >= ino) {
165		for (i = ctx->dir_info->count-1; i > 0; i--)
166			if (ctx->dir_info->array[i-1].ino < ino)
167				break;
168		dir = &ctx->dir_info->array[i];
169		if (dir->ino != ino)
170			for (j = ctx->dir_info->count++; j > i; j--)
171				ctx->dir_info->array[j] = ctx->dir_info->array[j-1];
172	} else
173		dir = &ctx->dir_info->array[ctx->dir_info->count++];
174
175	dir->ino = ino;
176	dir->dotdot = parent;
177	dir->parent = parent;
178}
179
180/*
181 * get_dir_info() --- given an inode number, try to find the directory
182 * information entry for it.
183 */
184static struct dir_info *e2fsck_get_dir_info(e2fsck_t ctx, ext2_ino_t ino)
185{
186	struct dir_info_db	*db = ctx->dir_info;
187	int			low, high, mid;
188	struct dir_info_ent	*buf;
189	static struct dir_info	ret_dir_info;
190
191	if (!db)
192		return 0;
193
194#ifdef DIRINFO_DEBUG
195	printf("e2fsck_get_dir_info %d...", ino);
196#endif
197
198	if (db->tdb) {
199		TDB_DATA key, data;
200
201		key.dptr = (unsigned char *) &ino;
202		key.dsize = sizeof(ext2_ino_t);
203
204		data = tdb_fetch(db->tdb, key);
205		if (!data.dptr) {
206			if (tdb_error(db->tdb) != TDB_ERR_NOEXIST)
207				printf("fetch failed: %s\n",
208				       tdb_errorstr(db->tdb));
209			return 0;
210		}
211
212		buf = (struct dir_info_ent *) data.dptr;
213		ret_dir_info.ino = ino;
214		ret_dir_info.dotdot = buf->dotdot;
215		ret_dir_info.parent = buf->parent;
216#ifdef DIRINFO_DEBUG
217		printf("(%d,%d,%d)\n", ino, buf->dotdot, buf->parent);
218#endif
219		free(data.dptr);
220		return &ret_dir_info;
221	}
222
223	if (db->last_lookup && db->last_lookup->ino == ino)
224		return db->last_lookup;
225
226	low = 0;
227	high = ctx->dir_info->count-1;
228	if (ino == ctx->dir_info->array[low].ino) {
229#ifdef DIRINFO_DEBUG
230		printf("(%d,%d,%d)\n", ino,
231		       ctx->dir_info->array[low].dotdot,
232		       ctx->dir_info->array[low].parent);
233#endif
234		return &ctx->dir_info->array[low];
235	}
236	if (ino == ctx->dir_info->array[high].ino) {
237#ifdef DIRINFO_DEBUG
238		printf("(%d,%d,%d)\n", ino,
239		       ctx->dir_info->array[high].dotdot,
240		       ctx->dir_info->array[high].parent);
241#endif
242		return &ctx->dir_info->array[high];
243	}
244
245	while (low < high) {
246		mid = (low+high)/2;
247		if (mid == low || mid == high)
248			break;
249		if (ino == ctx->dir_info->array[mid].ino) {
250#ifdef DIRINFO_DEBUG
251			printf("(%d,%d,%d)\n", ino,
252			       ctx->dir_info->array[mid].dotdot,
253			       ctx->dir_info->array[mid].parent);
254#endif
255			return &ctx->dir_info->array[mid];
256		}
257		if (ino < ctx->dir_info->array[mid].ino)
258			high = mid;
259		else
260			low = mid;
261	}
262	return 0;
263}
264
265static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir)
266{
267	struct dir_info_db	*db = ctx->dir_info;
268	struct dir_info_ent	buf;
269	TDB_DATA		key, data;
270
271#ifdef DIRINFO_DEBUG
272	printf("e2fsck_put_dir_info (%d, %d, %d)...", dir->ino, dir->dotdot,
273	       dir->parent);
274#endif
275
276	if (!db->tdb)
277		return;
278
279	buf.parent = dir->parent;
280	buf.dotdot = dir->dotdot;
281
282	key.dptr = (unsigned char *) &dir->ino;
283	key.dsize = sizeof(ext2_ino_t);
284	data.dptr = (unsigned char *) &buf;
285	data.dsize = sizeof(buf);
286
287	if (tdb_store(db->tdb, key, data, TDB_REPLACE) == -1) {
288		printf("store failed: %s\n", tdb_errorstr(db->tdb));
289	}
290	return;
291}
292
293/*
294 * Free the dir_info structure when it isn't needed any more.
295 */
296void e2fsck_free_dir_info(e2fsck_t ctx)
297{
298	if (ctx->dir_info) {
299		if (ctx->dir_info->tdb)
300			tdb_close(ctx->dir_info->tdb);
301		if (ctx->dir_info->tdb_fn) {
302			unlink(ctx->dir_info->tdb_fn);
303			free(ctx->dir_info->tdb_fn);
304		}
305		if (ctx->dir_info->array)
306			ext2fs_free_mem(&ctx->dir_info->array);
307		ctx->dir_info->array = 0;
308		ctx->dir_info->size = 0;
309		ctx->dir_info->count = 0;
310		ext2fs_free_mem(&ctx->dir_info);
311		ctx->dir_info = 0;
312	}
313}
314
315/*
316 * Return the count of number of directories in the dir_info structure
317 */
318int e2fsck_get_num_dirinfo(e2fsck_t ctx)
319{
320	return ctx->dir_info ? ctx->dir_info->count : 0;
321}
322
323struct dir_info_iter *e2fsck_dir_info_iter_begin(e2fsck_t ctx)
324{
325	struct dir_info_iter *iter;
326	struct dir_info_db *db = ctx->dir_info;
327
328	iter = e2fsck_allocate_memory(ctx, sizeof(struct dir_info_iter),
329				      "dir_info iterator");
330
331	if (db->tdb)
332		iter->tdb_iter = tdb_firstkey(db->tdb);
333
334	return iter;
335}
336
337void e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR((unused)),
338			      struct dir_info_iter *iter)
339{
340	free(iter->tdb_iter.dptr);
341	ext2fs_free_mem(&iter);
342}
343
344/*
345 * A simple interator function
346 */
347struct dir_info *e2fsck_dir_info_iter(e2fsck_t ctx, struct dir_info_iter *iter)
348{
349	TDB_DATA data, key;
350	struct dir_info_db *db = ctx->dir_info;
351	struct dir_info_ent *buf;
352	static struct dir_info ret_dir_info;
353
354	if (!ctx->dir_info || !iter)
355		return 0;
356
357	if (db->tdb) {
358		if (iter->tdb_iter.dptr == 0)
359			return 0;
360		key = iter->tdb_iter;
361		data = tdb_fetch(db->tdb, key);
362		if (!data.dptr) {
363			printf("iter fetch failed: %s\n",
364			       tdb_errorstr(db->tdb));
365			return 0;
366		}
367		buf = (struct dir_info_ent *) data.dptr;
368		ret_dir_info.ino = *((ext2_ino_t *) iter->tdb_iter.dptr);
369		ret_dir_info.dotdot = buf->dotdot;
370		ret_dir_info.parent = buf->parent;
371		iter->tdb_iter = tdb_nextkey(db->tdb, key);
372		free(key.dptr);
373		free(data.dptr);
374		return &ret_dir_info;
375	}
376
377	if (iter->i >= ctx->dir_info->count)
378		return 0;
379
380#ifdef DIRINFO_DEBUG
381	printf("iter(%d, %d, %d)...", ctx->dir_info->array[iter->i].ino,
382	       ctx->dir_info->array[iter->i].dotdot,
383	       ctx->dir_info->array[iter->i].parent);
384#endif
385	ctx->dir_info->last_lookup = ctx->dir_info->array + iter->i++;
386	return(ctx->dir_info->last_lookup);
387}
388
389/*
390 * This function only sets the parent pointer, and requires that
391 * dirinfo structure has already been created.
392 */
393int e2fsck_dir_info_set_parent(e2fsck_t ctx, ext2_ino_t ino,
394			       ext2_ino_t parent)
395{
396	struct dir_info *p;
397
398	p = e2fsck_get_dir_info(ctx, ino);
399	if (!p)
400		return 1;
401	p->parent = parent;
402	e2fsck_put_dir_info(ctx, p);
403	return 0;
404}
405
406/*
407 * This function only sets the dot dot pointer, and requires that
408 * dirinfo structure has already been created.
409 */
410int e2fsck_dir_info_set_dotdot(e2fsck_t ctx, ext2_ino_t ino,
411			       ext2_ino_t dotdot)
412{
413	struct dir_info *p;
414
415	p = e2fsck_get_dir_info(ctx, ino);
416	if (!p)
417		return 1;
418	p->dotdot = dotdot;
419	e2fsck_put_dir_info(ctx, p);
420	return 0;
421}
422
423/*
424 * This function only sets the parent pointer, and requires that
425 * dirinfo structure has already been created.
426 */
427int e2fsck_dir_info_get_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	*parent = p->parent;
436	return 0;
437}
438
439/*
440 * This function only sets the dot dot pointer, and requires that
441 * dirinfo structure has already been created.
442 */
443int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
444			       ext2_ino_t *dotdot)
445{
446	struct dir_info *p;
447
448	p = e2fsck_get_dir_info(ctx, ino);
449	if (!p)
450		return 1;
451	*dotdot = p->dotdot;
452	return 0;
453}
454
455