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 Library
8 * General Public License, version 2.
9 * %End-Header%
10 */
11
12 #include <stdio.h>
13 #if HAVE_UNISTD_H
14 #include <unistd.h>
15 #endif
16 #include <string.h>
17 #include <time.h>
18
19 #include "ext2_fs.h"
20 #include "ext2fsP.h"
21
22 static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b);
23
24 /*
25 * Returns the number of directories in the filesystem as reported by
26 * the group descriptors. Of course, the group descriptors could be
27 * wrong!
28 */
ext2fs_get_num_dirs(ext2_filsys fs,ext2_ino_t * ret_num_dirs)29 errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs)
30 {
31 dgrp_t i;
32 ext2_ino_t num_dirs, max_dirs;
33
34 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
35
36 num_dirs = 0;
37 max_dirs = fs->super->s_inodes_per_group;
38 for (i = 0; i < fs->group_desc_count; i++) {
39 if (fs->group_desc[i].bg_used_dirs_count > max_dirs)
40 num_dirs += max_dirs / 8;
41 else
42 num_dirs += fs->group_desc[i].bg_used_dirs_count;
43 }
44 if (num_dirs > fs->super->s_inodes_count)
45 num_dirs = fs->super->s_inodes_count;
46
47 *ret_num_dirs = num_dirs;
48
49 return 0;
50 }
51
52 /*
53 * helper function for making a new directory block list (for
54 * initialize and copy).
55 */
make_dblist(ext2_filsys fs,ext2_ino_t size,ext2_ino_t count,struct ext2_db_entry * list,ext2_dblist * ret_dblist)56 static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size, ext2_ino_t count,
57 struct ext2_db_entry *list,
58 ext2_dblist *ret_dblist)
59 {
60 ext2_dblist dblist;
61 errcode_t retval;
62 size_t len;
63
64 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
65
66 if ((ret_dblist == 0) && fs->dblist &&
67 (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
68 return 0;
69
70 retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
71 if (retval)
72 return retval;
73 memset(dblist, 0, sizeof(struct ext2_struct_dblist));
74
75 dblist->magic = EXT2_ET_MAGIC_DBLIST;
76 dblist->fs = fs;
77 if (size)
78 dblist->size = size;
79 else {
80 retval = ext2fs_get_num_dirs(fs, &dblist->size);
81 if (retval)
82 goto cleanup;
83 dblist->size = (dblist->size * 2) + 12;
84 }
85 len = (size_t) sizeof(struct ext2_db_entry) * dblist->size;
86 dblist->count = count;
87 retval = ext2fs_get_array(dblist->size, sizeof(struct ext2_db_entry),
88 &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;
101 cleanup:
102 if (dblist)
103 ext2fs_free_mem(&dblist);
104 return retval;
105 }
106
107 /*
108 * Initialize a directory block list
109 */
ext2fs_init_dblist(ext2_filsys fs,ext2_dblist * ret_dblist)110 errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
111 {
112 ext2_dblist dblist;
113 errcode_t retval;
114
115 retval = make_dblist(fs, 0, 0, 0, &dblist);
116 if (retval)
117 return retval;
118
119 dblist->sorted = 1;
120 if (ret_dblist)
121 *ret_dblist = dblist;
122 else
123 fs->dblist = dblist;
124
125 return 0;
126 }
127
128 /*
129 * Copy a directory block list
130 */
ext2fs_copy_dblist(ext2_dblist src,ext2_dblist * dest)131 errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
132 {
133 ext2_dblist dblist;
134 errcode_t retval;
135
136 retval = make_dblist(src->fs, src->size, src->count, src->list,
137 &dblist);
138 if (retval)
139 return retval;
140 dblist->sorted = src->sorted;
141 *dest = dblist;
142 return 0;
143 }
144
145 /*
146 * Close a directory block list
147 *
148 * (moved to closefs.c)
149 */
150
151
152 /*
153 * Add a directory block to the directory block list
154 */
ext2fs_add_dir_block(ext2_dblist dblist,ext2_ino_t ino,blk_t blk,int blockcnt)155 errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
156 int blockcnt)
157 {
158 struct ext2_db_entry *new_entry;
159 errcode_t retval;
160 unsigned long old_size;
161
162 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
163
164 if (dblist->count >= dblist->size) {
165 old_size = dblist->size * sizeof(struct ext2_db_entry);
166 dblist->size += dblist->size > 200 ? dblist->size / 2 : 100;
167 retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
168 sizeof(struct ext2_db_entry),
169 &dblist->list);
170 if (retval) {
171 dblist->size -= 100;
172 return retval;
173 }
174 }
175 new_entry = dblist->list + ( (int) dblist->count++);
176 new_entry->blk = blk;
177 new_entry->ino = ino;
178 new_entry->blockcnt = blockcnt;
179
180 dblist->sorted = 0;
181
182 return 0;
183 }
184
185 /*
186 * Change the directory block to the directory block list
187 */
ext2fs_set_dir_block(ext2_dblist dblist,ext2_ino_t ino,blk_t blk,int blockcnt)188 errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
189 int blockcnt)
190 {
191 dgrp_t i;
192
193 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
194
195 for (i=0; i < dblist->count; i++) {
196 if ((dblist->list[i].ino != ino) ||
197 (dblist->list[i].blockcnt != blockcnt))
198 continue;
199 dblist->list[i].blk = blk;
200 dblist->sorted = 0;
201 return 0;
202 }
203 return EXT2_ET_DB_NOT_FOUND;
204 }
205
ext2fs_dblist_sort(ext2_dblist dblist,EXT2_QSORT_TYPE (* sortfunc)(const void *,const void *))206 void ext2fs_dblist_sort(ext2_dblist dblist,
207 EXT2_QSORT_TYPE (*sortfunc)(const void *,
208 const void *))
209 {
210 if (!sortfunc)
211 sortfunc = dir_block_cmp;
212 qsort(dblist->list, (size_t) dblist->count,
213 sizeof(struct ext2_db_entry), sortfunc);
214 dblist->sorted = 1;
215 }
216
217 /*
218 * This function iterates over the directory block list
219 */
ext2fs_dblist_iterate(ext2_dblist dblist,int (* func)(ext2_filsys fs,struct ext2_db_entry * db_info,void * priv_data),void * priv_data)220 errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
221 int (*func)(ext2_filsys fs,
222 struct ext2_db_entry *db_info,
223 void *priv_data),
224 void *priv_data)
225 {
226 ext2_ino_t i;
227 int ret;
228
229 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
230
231 if (!dblist->sorted)
232 ext2fs_dblist_sort(dblist, 0);
233 for (i=0; i < dblist->count; i++) {
234 ret = (*func)(dblist->fs, &dblist->list[(int)i], priv_data);
235 if (ret & DBLIST_ABORT)
236 return 0;
237 }
238 return 0;
239 }
240
dir_block_cmp(const void * a,const void * b)241 static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b)
242 {
243 const struct ext2_db_entry *db_a =
244 (const struct ext2_db_entry *) a;
245 const struct ext2_db_entry *db_b =
246 (const struct ext2_db_entry *) b;
247
248 if (db_a->blk != db_b->blk)
249 return (int) (db_a->blk - db_b->blk);
250
251 if (db_a->ino != db_b->ino)
252 return (int) (db_a->ino - db_b->ino);
253
254 return (int) (db_a->blockcnt - db_b->blockcnt);
255 }
256
ext2fs_dblist_count(ext2_dblist dblist)257 int ext2fs_dblist_count(ext2_dblist dblist)
258 {
259 return (int) dblist->count;
260 }
261
ext2fs_dblist_get_last(ext2_dblist dblist,struct ext2_db_entry ** entry)262 errcode_t ext2fs_dblist_get_last(ext2_dblist dblist,
263 struct ext2_db_entry **entry)
264 {
265 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
266
267 if (dblist->count == 0)
268 return EXT2_ET_DBLIST_EMPTY;
269
270 if (entry)
271 *entry = dblist->list + ( (int) dblist->count-1);
272 return 0;
273 }
274
ext2fs_dblist_drop_last(ext2_dblist dblist)275 errcode_t ext2fs_dblist_drop_last(ext2_dblist dblist)
276 {
277 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
278
279 if (dblist->count == 0)
280 return EXT2_ET_DBLIST_EMPTY;
281
282 dblist->count--;
283 return 0;
284 }
285