dblist.c revision 31dbecd482405e0d3a67eb58e1a1c8cb9f2ad83e
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#if EXT2_FLAT_INCLUDES 21#include "ext2_fs.h" 22#else 23#include <linux/ext2_fs.h> 24#endif 25 26#include "ext2fsP.h" 27 28static EXT2_QSORT_TYPE dir_block_cmp(const void *a, const void *b); 29 30/* 31 * Returns the number of directories in the filesystem as reported by 32 * the group descriptors. Of course, the group descriptors could be 33 * wrong! 34 */ 35errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs) 36{ 37 dgrp_t i; 38 ext2_ino_t num_dirs, max_dirs; 39 40 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 41 42 num_dirs = 0; 43 max_dirs = fs->super->s_inodes_per_group; 44 for (i = 0; i < fs->group_desc_count; i++) { 45 if (fs->group_desc[i].bg_used_dirs_count > max_dirs) 46 num_dirs += max_dirs / 8; 47 else 48 num_dirs += fs->group_desc[i].bg_used_dirs_count; 49 } 50 if (num_dirs > fs->super->s_inodes_count) 51 num_dirs = fs->super->s_inodes_count; 52 53 *ret_num_dirs = num_dirs; 54 55 return 0; 56} 57 58/* 59 * helper function for making a new directory block list (for 60 * initialize and copy). 61 */ 62static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size, ext2_ino_t count, 63 struct ext2_db_entry *list, 64 ext2_dblist *ret_dblist) 65{ 66 ext2_dblist dblist; 67 errcode_t retval; 68 size_t len; 69 70 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 71 72 if ((ret_dblist == 0) && fs->dblist && 73 (fs->dblist->magic == EXT2_ET_MAGIC_DBLIST)) 74 return 0; 75 76 retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), 77 (void **) &dblist); 78 if (retval) 79 return retval; 80 memset(dblist, 0, sizeof(struct ext2_struct_dblist)); 81 82 dblist->magic = EXT2_ET_MAGIC_DBLIST; 83 dblist->fs = fs; 84 if (size) 85 dblist->size = size; 86 else { 87 retval = ext2fs_get_num_dirs(fs, &dblist->size); 88 if (retval) 89 goto cleanup; 90 dblist->size = (dblist->size * 2) + 12; 91 } 92 len = (size_t) sizeof(struct ext2_db_entry) * dblist->size; 93 dblist->count = count; 94 retval = ext2fs_get_mem(len, (void **) &dblist->list); 95 if (retval) 96 goto cleanup; 97 98 if (list) 99 memcpy(dblist->list, list, len); 100 else 101 memset(dblist->list, 0, len); 102 if (ret_dblist) 103 *ret_dblist = dblist; 104 else 105 fs->dblist = dblist; 106 return 0; 107cleanup: 108 if (dblist) 109 ext2fs_free_mem((void **) &dblist); 110 return retval; 111} 112 113/* 114 * Initialize a directory block list 115 */ 116errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist) 117{ 118 ext2_dblist dblist; 119 errcode_t retval; 120 121 retval = make_dblist(fs, 0, 0, 0, &dblist); 122 if (retval) 123 return retval; 124 125 dblist->sorted = 1; 126 if (ret_dblist) 127 *ret_dblist = dblist; 128 else 129 fs->dblist = dblist; 130 131 return 0; 132} 133 134/* 135 * Copy a directory block list 136 */ 137errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest) 138{ 139 ext2_dblist dblist; 140 errcode_t retval; 141 142 retval = make_dblist(src->fs, src->size, src->count, src->list, 143 &dblist); 144 if (retval) 145 return retval; 146 dblist->sorted = src->sorted; 147 *dest = dblist; 148 return 0; 149} 150 151/* 152 * Close a directory block list 153 * 154 * (moved to closefs.c) 155 */ 156 157 158/* 159 * Add a directory block to the directory block list 160 */ 161errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk, 162 int blockcnt) 163{ 164 struct ext2_db_entry *new_entry; 165 errcode_t retval; 166 unsigned long old_size; 167 168 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST); 169 170 if (dblist->count >= dblist->size) { 171 old_size = dblist->size * sizeof(struct ext2_db_entry); 172 dblist->size += 100; 173 retval = ext2fs_resize_mem(old_size, (size_t) dblist->size * 174 sizeof(struct ext2_db_entry), 175 (void **) &dblist->list); 176 if (retval) { 177 dblist->size -= 100; 178 return retval; 179 } 180 } 181 new_entry = dblist->list + ( (int) dblist->count++); 182 new_entry->blk = blk; 183 new_entry->ino = ino; 184 new_entry->blockcnt = blockcnt; 185 186 dblist->sorted = 0; 187 188 return 0; 189} 190 191/* 192 * Change the directory block to the directory block list 193 */ 194errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk, 195 int blockcnt) 196{ 197 dgrp_t i; 198 199 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST); 200 201 for (i=0; i < dblist->count; i++) { 202 if ((dblist->list[i].ino != ino) || 203 (dblist->list[i].blockcnt != blockcnt)) 204 continue; 205 dblist->list[i].blk = blk; 206 dblist->sorted = 0; 207 return 0; 208 } 209 return EXT2_ET_DB_NOT_FOUND; 210} 211 212/* 213 * This function iterates over the directory block list 214 */ 215errcode_t ext2fs_dblist_iterate(ext2_dblist dblist, 216 int (*func)(ext2_filsys fs, 217 struct ext2_db_entry *db_info, 218 void *priv_data), 219 void *priv_data) 220{ 221 ext2_ino_t i; 222 int ret; 223 224 EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST); 225 226 if (!dblist->sorted) { 227 qsort(dblist->list, (size_t) dblist->count, 228 sizeof(struct ext2_db_entry), dir_block_cmp); 229 dblist->sorted = 1; 230 } 231 for (i=0; i < dblist->count; i++) { 232 ret = (*func)(dblist->fs, &dblist->list[(int)i], priv_data); 233 if (ret & DBLIST_ABORT) 234 return 0; 235 } 236 return 0; 237} 238 239 240static EXT2_QSORT_TYPE 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} 260