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 */ 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 */ 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 */ 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 */ 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 */ 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 += 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 */ 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 } 206 207 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 */ 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 } 241 242 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 } 257 258 int ext2fs_dblist_count(ext2_dblist dblist) 259 { 260 return (int) dblist->count; 261 } 262 263 errcode_t ext2fs_dblist_get_last(ext2_dblist dblist, 264 struct ext2_db_entry **entry) 265 { 266 errcode_t retval; 267 268 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST); 269 270 if (dblist->count == 0) 271 return EXT2_ET_DBLIST_EMPTY; 272 273 if (entry) 274 *entry = dblist->list + ( (int) dblist->count-1); 275 return 0; 276 } 277 278 errcode_t ext2fs_dblist_drop_last(ext2_dblist dblist) 279 { 280 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST); 281 282 if (dblist->count == 0) 283 return EXT2_ET_DBLIST_EMPTY; 284 285 dblist->count--; 286 return 0; 287 } 288
