dirinfo.c revision beec19ff21d41c84dbbc2ab8d0df25147912ff59 
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	mode_t			save_umask;
46	char			*tdb_dir, uuid[40];
47	int			fd, enable;
48
49	profile_get_string(ctx->profile, "scratch_files", "directory", 0, 0,
50			   &tdb_dir);
51	profile_get_uint(ctx->profile, "scratch_files",
52			 "numdirs_threshold", 0, 0, &threshold);
53	profile_get_boolean(ctx->profile, "scratch_files",
54			    "dirinfo", 0, 1, &enable);
55
56	if (!enable || !tdb_dir || access(tdb_dir, W_OK) ||
57	    (threshold && num_dirs <= threshold))
58		return;
59
60	retval = ext2fs_get_mem(strlen(tdb_dir) + 64, &db->tdb_fn);
61	if (retval)
62		return;
63
64	uuid_unparse(ctx->fs->super->s_uuid, uuid);
65	sprintf(db->tdb_fn, "%s/%s-dirinfo-XXXXXX", tdb_dir, uuid);
66	save_umask = umask(077);
67	fd = mkstemp(db->tdb_fn);
68	umask(save_umask);
69	if (fd < 0) {
70		db->tdb = NULL;
71		return;
72	}
73
74	if (num_dirs < 99991)
75		num_dirs = 99991; /* largest 5 digit prime */
76
77	db->tdb = tdb_open(db->tdb_fn, num_dirs, TDB_NOLOCK | TDB_NOSYNC,
78			   O_RDWR | O_CREAT | O_TRUNC, 0600);
79	close(fd);
80}
81
82static void setup_db(e2fsck_t ctx)
83{
84	struct dir_info_db	*db;
85	ext2_ino_t		num_dirs;
86	errcode_t		retval;
87
88	db = (struct dir_info_db *)
89		e2fsck_allocate_memory(ctx, sizeof(struct dir_info_db),
90				       "directory map db");
91	db->count = db->size = 0;
92	db->array = 0;
93
94	ctx->dir_info = db;
95
96	retval = ext2fs_get_num_dirs(ctx->fs, &num_dirs);
97	if (retval)
98		num_dirs = 1024;	/* Guess */
99
100	setup_tdb(ctx, num_dirs);
101
102	if (db->tdb) {
103#ifdef DIRINFO_DEBUG
104		printf("Note: using tdb!\n");
105#endif
106		return;
107	}
108
109	db->size = num_dirs + 10;
110	db->array  = (struct dir_info *)
111		e2fsck_allocate_memory(ctx, db->size
112				       * sizeof (struct dir_info),
113				       "directory map");
114}
115
116/*
117 * This subroutine is called during pass1 to create a directory info
118 * entry.  During pass1, the passed-in parent is 0; it will get filled
119 * in during pass2.
120 */
121void e2fsck_add_dir_info(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
122{
123	struct dir_info_db 	*db;
124	struct dir_info		*dir, ent, *old_array;
125	int			i, j;
126	errcode_t		retval;
127	unsigned long		old_size;
128
129#ifdef DIRINFO_DEBUG
130	printf("add_dir_info for inode (%lu, %lu)...\n", ino, parent);
131#endif
132	if (!ctx->dir_info)
133		setup_db(ctx);
134	db = ctx->dir_info;
135
136	if (ctx->dir_info->count >= ctx->dir_info->size) {
137		old_size = ctx->dir_info->size * sizeof(struct dir_info);
138		ctx->dir_info->size += 10;
139		old_array = ctx->dir_info->array;
140		retval = ext2fs_resize_mem(old_size, ctx->dir_info->size *
141					   sizeof(struct dir_info),
142					   &ctx->dir_info->array);
143		if (retval) {
144			fprintf(stderr, "Couldn't reallocate dir_info "
145				"structure to %d entries\n",
146				ctx->dir_info->size);
147			fatal_error(ctx, 0);
148			ctx->dir_info->size -= 10;
149			return;
150		}
151		if (old_array != ctx->dir_info->array)
152			ctx->dir_info->last_lookup = NULL;
153	}
154
155	ent.ino = ino;
156	ent.parent = parent;
157	ent.dotdot = parent;
158
159	if (db->tdb) {
160		e2fsck_put_dir_info(ctx, &ent);
161		return;
162	}
163
164	/*
165	 * Normally, add_dir_info is called with each inode in
166	 * sequential order; but once in a while (like when pass 3
167	 * needs to recreate the root directory or lost+found
168	 * directory) it is called out of order.  In those cases, we
169	 * need to move the dir_info entries down to make room, since
170	 * the dir_info array needs to be sorted by inode number for
171	 * get_dir_info()'s sake.
172	 */
173	if (ctx->dir_info->count &&
174	    ctx->dir_info->array[ctx->dir_info->count-1].ino >= ino) {
175		for (i = ctx->dir_info->count-1; i > 0; i--)
176			if (ctx->dir_info->array[i-1].ino < ino)
177				break;
178		dir = &ctx->dir_info->array[i];
179		if (dir->ino != ino)
180			for (j = ctx->dir_info->count++; j > i; j--)
181				ctx->dir_info->array[j] = ctx->dir_info->array[j-1];
182	} else
183		dir = &ctx->dir_info->array[ctx->dir_info->count++];
184
185	dir->ino = ino;
186	dir->dotdot = parent;
187	dir->parent = parent;
188}
189
190/*
191 * get_dir_info() --- given an inode number, try to find the directory
192 * information entry for it.
193 */
194static struct dir_info *e2fsck_get_dir_info(e2fsck_t ctx, ext2_ino_t ino)
195{
196	struct dir_info_db	*db = ctx->dir_info;
197	int			low, high, mid;
198	struct dir_info_ent	*buf;
199	static struct dir_info	ret_dir_info;
200
201	if (!db)
202		return 0;
203
204#ifdef DIRINFO_DEBUG
205	printf("e2fsck_get_dir_info %d...", ino);
206#endif
207
208	if (db->tdb) {
209		TDB_DATA key, data;
210
211		key.dptr = (unsigned char *) &ino;
212		key.dsize = sizeof(ext2_ino_t);
213
214		data = tdb_fetch(db->tdb, key);
215		if (!data.dptr) {
216			if (tdb_error(db->tdb) != TDB_ERR_NOEXIST)
217				printf("fetch failed: %s\n",
218				       tdb_errorstr(db->tdb));
219			return 0;
220		}
221
222		buf = (struct dir_info_ent *) data.dptr;
223		ret_dir_info.ino = ino;
224		ret_dir_info.dotdot = buf->dotdot;
225		ret_dir_info.parent = buf->parent;
226#ifdef DIRINFO_DEBUG
227		printf("(%d,%d,%d)\n", ino, buf->dotdot, buf->parent);
228#endif
229		free(data.dptr);
230		return &ret_dir_info;
231	}
232
233	if (db->last_lookup && db->last_lookup->ino == ino)
234		return db->last_lookup;
235
236	low = 0;
237	high = ctx->dir_info->count-1;
238	if (ino == ctx->dir_info->array[low].ino) {
239#ifdef DIRINFO_DEBUG
240		printf("(%d,%d,%d)\n", ino,
241		       ctx->dir_info->array[low].dotdot,
242		       ctx->dir_info->array[low].parent);
243#endif
244		return &ctx->dir_info->array[low];
245	}
246	if (ino == ctx->dir_info->array[high].ino) {
247#ifdef DIRINFO_DEBUG
248		printf("(%d,%d,%d)\n", ino,
249		       ctx->dir_info->array[high].dotdot,
250		       ctx->dir_info->array[high].parent);
251#endif
252		return &ctx->dir_info->array[high];
253	}
254
255	while (low < high) {
256		mid = (low+high)/2;
257		if (mid == low || mid == high)
258			break;
259		if (ino == ctx->dir_info->array[mid].ino) {
260#ifdef DIRINFO_DEBUG
261			printf("(%d,%d,%d)\n", ino,
262			       ctx->dir_info->array[mid].dotdot,
263			       ctx->dir_info->array[mid].parent);
264#endif
265			return &ctx->dir_info->array[mid];
266		}
267		if (ino < ctx->dir_info->array[mid].ino)
268			high = mid;
269		else
270			low = mid;
271	}
272	return 0;
273}
274
275static void e2fsck_put_dir_info(e2fsck_t ctx, struct dir_info *dir)
276{
277	struct dir_info_db	*db = ctx->dir_info;
278	struct dir_info_ent	buf;
279	TDB_DATA		key, data;
280
281#ifdef DIRINFO_DEBUG
282	printf("e2fsck_put_dir_info (%d, %d, %d)...", dir->ino, dir->dotdot,
283	       dir->parent);
284#endif
285
286	if (!db->tdb)
287		return;
288
289	buf.parent = dir->parent;
290	buf.dotdot = dir->dotdot;
291
292	key.dptr = (unsigned char *) &dir->ino;
293	key.dsize = sizeof(ext2_ino_t);
294	data.dptr = (unsigned char *) &buf;
295	data.dsize = sizeof(buf);
296
297	if (tdb_store(db->tdb, key, data, TDB_REPLACE) == -1) {
298		printf("store failed: %s\n", tdb_errorstr(db->tdb));
299	}
300	return;
301}
302
303/*
304 * Free the dir_info structure when it isn't needed any more.
305 */
306void e2fsck_free_dir_info(e2fsck_t ctx)
307{
308	if (ctx->dir_info) {
309		if (ctx->dir_info->tdb)
310			tdb_close(ctx->dir_info->tdb);
311		if (ctx->dir_info->tdb_fn) {
312			unlink(ctx->dir_info->tdb_fn);
313			free(ctx->dir_info->tdb_fn);
314		}
315		if (ctx->dir_info->array)
316			ext2fs_free_mem(&ctx->dir_info->array);
317		ctx->dir_info->array = 0;
318		ctx->dir_info->size = 0;
319		ctx->dir_info->count = 0;
320		ext2fs_free_mem(&ctx->dir_info);
321		ctx->dir_info = 0;
322	}
323}
324
325/*
326 * Return the count of number of directories in the dir_info structure
327 */
328int e2fsck_get_num_dirinfo(e2fsck_t ctx)
329{
330	return ctx->dir_info ? ctx->dir_info->count : 0;
331}
332
333struct dir_info_iter *e2fsck_dir_info_iter_begin(e2fsck_t ctx)
334{
335	struct dir_info_iter *iter;
336	struct dir_info_db *db = ctx->dir_info;
337
338	iter = e2fsck_allocate_memory(ctx, sizeof(struct dir_info_iter),
339				      "dir_info iterator");
340
341	if (db->tdb)
342		iter->tdb_iter = tdb_firstkey(db->tdb);
343
344	return iter;
345}
346
347void e2fsck_dir_info_iter_end(e2fsck_t ctx EXT2FS_ATTR((unused)),
348			      struct dir_info_iter *iter)
349{
350	free(iter->tdb_iter.dptr);
351	ext2fs_free_mem(&iter);
352}
353
354/*
355 * A simple interator function
356 */
357struct dir_info *e2fsck_dir_info_iter(e2fsck_t ctx, struct dir_info_iter *iter)
358{
359	TDB_DATA data, key;
360	struct dir_info_db *db = ctx->dir_info;
361	struct dir_info_ent *buf;
362	static struct dir_info ret_dir_info;
363
364	if (!ctx->dir_info || !iter)
365		return 0;
366
367	if (db->tdb) {
368		if (iter->tdb_iter.dptr == 0)
369			return 0;
370		key = iter->tdb_iter;
371		data = tdb_fetch(db->tdb, key);
372		if (!data.dptr) {
373			printf("iter fetch failed: %s\n",
374			       tdb_errorstr(db->tdb));
375			return 0;
376		}
377		buf = (struct dir_info_ent *) data.dptr;
378		ret_dir_info.ino = *((ext2_ino_t *) iter->tdb_iter.dptr);
379		ret_dir_info.dotdot = buf->dotdot;
380		ret_dir_info.parent = buf->parent;
381		iter->tdb_iter = tdb_nextkey(db->tdb, key);
382		free(key.dptr);
383		free(data.dptr);
384		return &ret_dir_info;
385	}
386
387	if (iter->i >= ctx->dir_info->count)
388		return 0;
389
390#ifdef DIRINFO_DEBUG
391	printf("iter(%d, %d, %d)...", ctx->dir_info->array[iter->i].ino,
392	       ctx->dir_info->array[iter->i].dotdot,
393	       ctx->dir_info->array[iter->i].parent);
394#endif
395	ctx->dir_info->last_lookup = ctx->dir_info->array + iter->i++;
396	return(ctx->dir_info->last_lookup);
397}
398
399/*
400 * This function only sets the parent pointer, and requires that
401 * dirinfo structure has already been created.
402 */
403int e2fsck_dir_info_set_parent(e2fsck_t ctx, ext2_ino_t ino,
404			       ext2_ino_t parent)
405{
406	struct dir_info *p;
407
408	p = e2fsck_get_dir_info(ctx, ino);
409	if (!p)
410		return 1;
411	p->parent = parent;
412	e2fsck_put_dir_info(ctx, p);
413	return 0;
414}
415
416/*
417 * This function only sets the dot dot pointer, and requires that
418 * dirinfo structure has already been created.
419 */
420int e2fsck_dir_info_set_dotdot(e2fsck_t ctx, ext2_ino_t ino,
421			       ext2_ino_t dotdot)
422{
423	struct dir_info *p;
424
425	p = e2fsck_get_dir_info(ctx, ino);
426	if (!p)
427		return 1;
428	p->dotdot = dotdot;
429	e2fsck_put_dir_info(ctx, p);
430	return 0;
431}
432
433/*
434 * This function only sets the parent pointer, and requires that
435 * dirinfo structure has already been created.
436 */
437int e2fsck_dir_info_get_parent(e2fsck_t ctx, ext2_ino_t ino,
438			       ext2_ino_t *parent)
439{
440	struct dir_info *p;
441
442	p = e2fsck_get_dir_info(ctx, ino);
443	if (!p)
444		return 1;
445	*parent = p->parent;
446	return 0;
447}
448
449/*
450 * This function only sets the dot dot pointer, and requires that
451 * dirinfo structure has already been created.
452 */
453int e2fsck_dir_info_get_dotdot(e2fsck_t ctx, ext2_ino_t ino,
454			       ext2_ino_t *dotdot)
455{
456	struct dir_info *p;
457
458	p = e2fsck_get_dir_info(ctx, ino);
459	if (!p)
460		return 1;
461	*dotdot = p->dotdot;
462	return 0;
463}
464
465