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
23 static EXT2_QSORT_TYPE 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 */
ext2fs_get_num_dirs(ext2_filsys fs,ext2_ino_t * ret_num_dirs)30 errcode_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 */
make_dblist(ext2_filsys fs,ext2_ino_t size,ext2_ino_t count,struct ext2_db_entry * list,ext2_dblist * ret_dblist)57 static 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_array(dblist->size, sizeof(struct ext2_db_entry),
89 &dblist->list);
90 if (retval)
91 goto cleanup;
92
93 if (list)
94 memcpy(dblist->list, list, len);
95 else
96 memset(dblist->list, 0, len);
97 if (ret_dblist)
98 *ret_dblist = dblist;
99 else
100 fs->dblist = dblist;
101 return 0;
102 cleanup:
103 if (dblist)
104 ext2fs_free_mem(&dblist);
105 return retval;
106 }
107
108 /*
109 * Initialize a directory block list
110 */
ext2fs_init_dblist(ext2_filsys fs,ext2_dblist * ret_dblist)111 errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
112 {
113 ext2_dblist dblist;
114 errcode_t retval;
115
116 retval = make_dblist(fs, 0, 0, 0, &dblist);
117 if (retval)
118 return retval;
119
120 dblist->sorted = 1;
121 if (ret_dblist)
122 *ret_dblist = dblist;
123 else
124 fs->dblist = dblist;
125
126 return 0;
127 }
128
129 /*
130 * Copy a directory block list
131 */
ext2fs_copy_dblist(ext2_dblist src,ext2_dblist * dest)132 errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
133 {
134 ext2_dblist dblist;
135 errcode_t retval;
136
137 retval = make_dblist(src->fs, src->size, src->count, src->list,
138 &dblist);
139 if (retval)
140 return retval;
141 dblist->sorted = src->sorted;
142 *dest = dblist;
143 return 0;
144 }
145
146 /*
147 * Close a directory block list
148 *
149 * (moved to closefs.c)
150 */
151
152
153 /*
154 * Add a directory block to the directory block list
155 */
ext2fs_add_dir_block(ext2_dblist dblist,ext2_ino_t ino,blk_t blk,int blockcnt)156 errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
157 int blockcnt)
158 {
159 struct ext2_db_entry *new_entry;
160 errcode_t retval;
161 unsigned long old_size;
162
163 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
164
165 if (dblist->count >= dblist->size) {
166 old_size = dblist->size * sizeof(struct ext2_db_entry);
167 dblist->size += dblist->size > 200 ? dblist->size / 2 : 100;
168 retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
169 sizeof(struct ext2_db_entry),
170 &dblist->list);
171 if (retval) {
172 dblist->size -= 100;
173 return retval;
174 }
175 }
176 new_entry = dblist->list + ( (int) dblist->count++);
177 new_entry->blk = blk;
178 new_entry->ino = ino;
179 new_entry->blockcnt = blockcnt;
180
181 dblist->sorted = 0;
182
183 return 0;
184 }
185
186 /*
187 * Change the directory block to the directory block list
188 */
ext2fs_set_dir_block(ext2_dblist dblist,ext2_ino_t ino,blk_t blk,int blockcnt)189 errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
190 int blockcnt)
191 {
192 dgrp_t i;
193
194 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
195
196 for (i=0; i < dblist->count; i++) {
197 if ((dblist->list[i].ino != ino) ||
198 (dblist->list[i].blockcnt != blockcnt))
199 continue;
200 dblist->list[i].blk = blk;
201 dblist->sorted = 0;
202 return 0;
203 }
204 return EXT2_ET_DB_NOT_FOUND;
205 }
206
ext2fs_dblist_sort(ext2_dblist dblist,EXT2_QSORT_TYPE (* sortfunc)(const void *,const void *))207 void ext2fs_dblist_sort(ext2_dblist dblist,
208 EXT2_QSORT_TYPE (*sortfunc)(const void *,
209 const void *))
210 {
211 if (!sortfunc)
212 sortfunc = dir_block_cmp;
213 qsort(dblist->list, (size_t) dblist->count,
214 sizeof(struct ext2_db_entry), sortfunc);
215 dblist->sorted = 1;
216 }
217
218 /*
219 * This function iterates over the directory block list
220 */
ext2fs_dblist_iterate(ext2_dblist dblist,int (* func)(ext2_filsys fs,struct ext2_db_entry * db_info,void * priv_data),void * priv_data)221 errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
222 int (*func)(ext2_filsys fs,
223 struct ext2_db_entry *db_info,
224 void *priv_data),
225 void *priv_data)
226 {
227 ext2_ino_t i;
228 int ret;
229
230 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
231
232 if (!dblist->sorted)
233 ext2fs_dblist_sort(dblist, 0);
234 for (i=0; i < dblist->count; i++) {
235 ret = (*func)(dblist->fs, &dblist->list[(int)i], priv_data);
236 if (ret & DBLIST_ABORT)
237 return 0;
238 }
239 return 0;
240 }
241
dir_block_cmp(const void * a,const void * b)242 static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b)
243 {
244 const struct ext2_db_entry *db_a =
245 (const struct ext2_db_entry *) a;
246 const struct ext2_db_entry *db_b =
247 (const struct ext2_db_entry *) b;
248
249 if (db_a->blk != db_b->blk)
250 return (int) (db_a->blk - db_b->blk);
251
252 if (db_a->ino != db_b->ino)
253 return (int) (db_a->ino - db_b->ino);
254
255 return (int) (db_a->blockcnt - db_b->blockcnt);
256 }
257
ext2fs_dblist_count(ext2_dblist dblist)258 int ext2fs_dblist_count(ext2_dblist dblist)
259 {
260 return (int) dblist->count;
261 }
262
ext2fs_dblist_get_last(ext2_dblist dblist,struct ext2_db_entry ** entry)263 errcode_t ext2fs_dblist_get_last(ext2_dblist dblist,
264 struct ext2_db_entry **entry)
265 {
266 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
267
268 if (dblist->count == 0)
269 return EXT2_ET_DBLIST_EMPTY;
270
271 if (entry)
272 *entry = dblist->list + ( (int) dblist->count-1);
273 return 0;
274 }
275
ext2fs_dblist_drop_last(ext2_dblist dblist)276 errcode_t ext2fs_dblist_drop_last(ext2_dblist dblist)
277 {
278 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
279
280 if (dblist->count == 0)
281 return EXT2_ET_DBLIST_EMPTY;
282
283 dblist->count--;
284 return 0;
285 }
286