source: MondoRescue/branches/stable/mindi-busybox/e2fsprogs/ext2fs/dblist.c @ 821

Last change on this file since 821 was 821, checked in by Bruno Cornec, 14 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)

File size: 5.4 KB
Line 
1/*
2 * dblist.c -- directory block list functions
3 *
4 * Copyright 1997 by Theodore Ts'o
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Public
8 * License.
9 * %End-Header%
10 *
11 */
12
13#include <stdio.h>
14#if HAVE_UNISTD_H
15#include <unistd.h>
16#endif
17#include <string.h>
18#include <time.h>
19
20#include "ext2_fs.h"
21#include "ext2fsP.h"
22
23static int dir_block_cmp(const void *a, const void *b);
24
25/*
26 * Returns the number of directories in the filesystem as reported by
27 * the group descriptors.  Of course, the group descriptors could be
28 * wrong!
29 */
30errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs)
31{
32    dgrp_t  i;
33    ext2_ino_t  num_dirs, max_dirs;
34
35    EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
36
37    num_dirs = 0;
38    max_dirs = fs->super->s_inodes_per_group;
39    for (i = 0; i < fs->group_desc_count; i++) {
40        if (fs->group_desc[i].bg_used_dirs_count > max_dirs)
41            num_dirs += max_dirs / 8;
42        else
43            num_dirs += fs->group_desc[i].bg_used_dirs_count;
44    }
45    if (num_dirs > fs->super->s_inodes_count)
46        num_dirs = fs->super->s_inodes_count;
47
48    *ret_num_dirs = num_dirs;
49
50    return 0;
51}
52
53/*
54 * helper function for making a new directory block list (for
55 * initialize and copy).
56 */
57static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size, ext2_ino_t count,
58                 struct ext2_db_entry *list,
59                 ext2_dblist *ret_dblist)
60{
61    ext2_dblist dblist;
62    errcode_t   retval;
63    size_t      len;
64
65    EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
66
67    if ((ret_dblist == 0) && fs->dblist &&
68        (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
69        return 0;
70
71    retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
72    if (retval)
73        return retval;
74    memset(dblist, 0, sizeof(struct ext2_struct_dblist));
75
76    dblist->magic = EXT2_ET_MAGIC_DBLIST;
77    dblist->fs = fs;
78    if (size)
79        dblist->size = size;
80    else {
81        retval = ext2fs_get_num_dirs(fs, &dblist->size);
82        if (retval)
83            goto cleanup;
84        dblist->size = (dblist->size * 2) + 12;
85    }
86    len = (size_t) sizeof(struct ext2_db_entry) * dblist->size;
87    dblist->count = count;
88    retval = ext2fs_get_mem(len, &dblist->list);
89    if (retval)
90        goto cleanup;
91
92    if (list)
93        memcpy(dblist->list, list, len);
94    else
95        memset(dblist->list, 0, len);
96    if (ret_dblist)
97        *ret_dblist = dblist;
98    else
99        fs->dblist = dblist;
100    return 0;
101cleanup:
102    ext2fs_free_mem(&dblist);
103    return retval;
104}
105
106/*
107 * Initialize a directory block list
108 */
109errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
110{
111    ext2_dblist dblist;
112    errcode_t   retval;
113
114    retval = make_dblist(fs, 0, 0, 0, &dblist);
115    if (retval)
116        return retval;
117
118    dblist->sorted = 1;
119    if (ret_dblist)
120        *ret_dblist = dblist;
121    else
122        fs->dblist = dblist;
123
124    return 0;
125}
126
127/*
128 * Copy a directory block list
129 */
130errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
131{
132    ext2_dblist dblist;
133    errcode_t   retval;
134
135    retval = make_dblist(src->fs, src->size, src->count, src->list,
136                 &dblist);
137    if (retval)
138        return retval;
139    dblist->sorted = src->sorted;
140    *dest = dblist;
141    return 0;
142}
143
144/*
145 * Close a directory block list
146 *
147 * (moved to closefs.c)
148 */
149
150
151/*
152 * Add a directory block to the directory block list
153 */
154errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
155                   int blockcnt)
156{
157    struct ext2_db_entry    *new_entry;
158    errcode_t       retval;
159    unsigned long       old_size;
160
161    EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
162
163    if (dblist->count >= dblist->size) {
164        old_size = dblist->size * sizeof(struct ext2_db_entry);
165        dblist->size += 100;
166        retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
167                       sizeof(struct ext2_db_entry),
168                       &dblist->list);
169        if (retval) {
170            dblist->size -= 100;
171            return retval;
172        }
173    }
174    new_entry = dblist->list + ( (int) dblist->count++);
175    new_entry->blk = blk;
176    new_entry->ino = ino;
177    new_entry->blockcnt = blockcnt;
178
179    dblist->sorted = 0;
180
181    return 0;
182}
183
184/*
185 * Change the directory block to the directory block list
186 */
187errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
188                   int blockcnt)
189{
190    dgrp_t          i;
191
192    EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
193
194    for (i=0; i < dblist->count; i++) {
195        if ((dblist->list[i].ino != ino) ||
196            (dblist->list[i].blockcnt != blockcnt))
197            continue;
198        dblist->list[i].blk = blk;
199        dblist->sorted = 0;
200        return 0;
201    }
202    return EXT2_ET_DB_NOT_FOUND;
203}
204
205void ext2fs_dblist_sort(ext2_dblist dblist,
206            int (*sortfunc)(const void *,
207                            const void *))
208{
209    if (!sortfunc)
210        sortfunc = dir_block_cmp;
211    qsort(dblist->list, (size_t) dblist->count,
212          sizeof(struct ext2_db_entry), sortfunc);
213    dblist->sorted = 1;
214}
215
216/*
217 * This function iterates over the directory block list
218 */
219errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
220                int (*func)(ext2_filsys fs,
221                        struct ext2_db_entry *db_info,
222                        void    *priv_data),
223                void *priv_data)
224{
225    ext2_ino_t  i;
226    int     ret;
227
228    EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
229
230    if (!dblist->sorted)
231        ext2fs_dblist_sort(dblist, 0);
232    for (i=0; i < dblist->count; i++) {
233        ret = (*func)(dblist->fs, &dblist->list[(int)i], priv_data);
234        if (ret & DBLIST_ABORT)
235            return 0;
236    }
237    return 0;
238}
239
240static int dir_block_cmp(const void *a, const void *b)
241{
242    const struct ext2_db_entry *db_a =
243        (const struct ext2_db_entry *) a;
244    const struct ext2_db_entry *db_b =
245        (const struct ext2_db_entry *) b;
246
247    if (db_a->blk != db_b->blk)
248        return (int) (db_a->blk - db_b->blk);
249
250    if (db_a->ino != db_b->ino)
251        return (int) (db_a->ino - db_b->ino);
252
253    return (int) (db_a->blockcnt - db_b->blockcnt);
254}
255
256int ext2fs_dblist_count(ext2_dblist dblist)
257{
258    return (int) dblist->count;
259}
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