aboutsummaryrefslogtreecommitdiff
path: root/e2fsprogs/ext2fs/dblist.c
blob: 73313faf39df2e366a74142ac5a71163c5b04e44 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
 * dblist.c -- directory block list functions
 *
 * Copyright 1997 by Theodore Ts'o
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 *
 */

#include <stdio.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <time.h>

#include "ext2_fs.h"
#include "ext2fsP.h"

static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b);

/*
 * Returns the number of directories in the filesystem as reported by
 * the group descriptors.  Of course, the group descriptors could be
 * wrong!
 */
errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs)
{
	dgrp_t	i;
	ext2_ino_t	num_dirs, max_dirs;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	num_dirs = 0;
	max_dirs = fs->super->s_inodes_per_group;
	for (i = 0; i < fs->group_desc_count; i++) {
		if (fs->group_desc[i].bg_used_dirs_count > max_dirs)
			num_dirs += max_dirs / 8;
		else
			num_dirs += fs->group_desc[i].bg_used_dirs_count;
	}
	if (num_dirs > fs->super->s_inodes_count)
		num_dirs = fs->super->s_inodes_count;

	*ret_num_dirs = num_dirs;

	return 0;
}

/*
 * helper function for making a new directory block list (for
 * initialize and copy).
 */
static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size, ext2_ino_t count,
			     struct ext2_db_entry *list,
			     ext2_dblist *ret_dblist)
{
	ext2_dblist	dblist;
	errcode_t	retval;
	size_t		len;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	if ((ret_dblist == 0) && fs->dblist &&
	    (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
		return 0;

	retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
	if (retval)
		return retval;
	memset(dblist, 0, sizeof(struct ext2_struct_dblist));

	dblist->magic = EXT2_ET_MAGIC_DBLIST;
	dblist->fs = fs;
	if (size)
		dblist->size = size;
	else {
		retval = ext2fs_get_num_dirs(fs, &dblist->size);
		if (retval)
			goto cleanup;
		dblist->size = (dblist->size * 2) + 12;
	}
	len = (size_t) sizeof(struct ext2_db_entry) * dblist->size;
	dblist->count = count;
	retval = ext2fs_get_mem(len, &dblist->list);
	if (retval)
		goto cleanup;

	if (list)
		memcpy(dblist->list, list, len);
	else
		memset(dblist->list, 0, len);
	if (ret_dblist)
		*ret_dblist = dblist;
	else
		fs->dblist = dblist;
	return 0;
cleanup:
	ext2fs_free_mem(&dblist);
	return retval;
}

/*
 * Initialize a directory block list
 */
errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
{
	ext2_dblist	dblist;
	errcode_t	retval;

	retval = make_dblist(fs, 0, 0, 0, &dblist);
	if (retval)
		return retval;

	dblist->sorted = 1;
	if (ret_dblist)
		*ret_dblist = dblist;
	else
		fs->dblist = dblist;

	return 0;
}

/*
 * Copy a directory block list
 */
errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
{
	ext2_dblist	dblist;
	errcode_t	retval;

	retval = make_dblist(src->fs, src->size, src->count, src->list,
			     &dblist);
	if (retval)
		return retval;
	dblist->sorted = src->sorted;
	*dest = dblist;
	return 0;
}

/*
 * Close a directory block list
 *
 * (moved to closefs.c)
 */


/*
 * Add a directory block to the directory block list
 */
errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
			       int blockcnt)
{
	struct ext2_db_entry	*new_entry;
	errcode_t		retval;
	unsigned long		old_size;

	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);

	if (dblist->count >= dblist->size) {
		old_size = dblist->size * sizeof(struct ext2_db_entry);
		dblist->size += 100;
		retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
					   sizeof(struct ext2_db_entry),
					   &dblist->list);
		if (retval) {
			dblist->size -= 100;
			return retval;
		}
	}
	new_entry = dblist->list + ( (int) dblist->count++);
	new_entry->blk = blk;
	new_entry->ino = ino;
	new_entry->blockcnt = blockcnt;

	dblist->sorted = 0;

	return 0;
}

/*
 * Change the directory block to the directory block list
 */
errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
			       int blockcnt)
{
	dgrp_t			i;

	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);

	for (i=0; i < dblist->count; i++) {
		if ((dblist->list[i].ino != ino) ||
		    (dblist->list[i].blockcnt != blockcnt))
			continue;
		dblist->list[i].blk = blk;
		dblist->sorted = 0;
		return 0;
	}
	return EXT2_ET_DB_NOT_FOUND;
}

void ext2fs_dblist_sort(ext2_dblist dblist,
			EXT2_QSORT_TYPE (*sortfunc)(const void *,
						    const void *))
{
	if (!sortfunc)
		sortfunc = dir_block_cmp;
	qsort(dblist->list, (size_t) dblist->count,
	      sizeof(struct ext2_db_entry), sortfunc);
	dblist->sorted = 1;
}

/*
 * This function iterates over the directory block list
 */
errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
				int (*func)(ext2_filsys fs,
					    struct ext2_db_entry *db_info,
					    void	*priv_data),
				void *priv_data)
{
	ext2_ino_t	i;
	int		ret;

	EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);

	if (!dblist->sorted)
		ext2fs_dblist_sort(dblist, 0);
	for (i=0; i < dblist->count; i++) {
		ret = (*func)(dblist->fs, &dblist->list[(int)i], priv_data);
		if (ret & DBLIST_ABORT)
			return 0;
	}
	return 0;
}

static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b)
{
	const struct ext2_db_entry *db_a =
		(const struct ext2_db_entry *) a;
	const struct ext2_db_entry *db_b =
		(const struct ext2_db_entry *) b;

	if (db_a->blk != db_b->blk)
		return (int) (db_a->blk - db_b->blk);

	if (db_a->ino != db_b->ino)
		return (int) (db_a->ino - db_b->ino);

	return (int) (db_a->blockcnt - db_b->blockcnt);
}

int ext2fs_dblist_count(ext2_dblist dblist)
{
	return (int) dblist->count;
}