busybox/e2fsprogs/ext2fs/dblist.c

261 lines
5.5 KiB
C

/* vi: set sw=4 ts=4: */
/*
* dblist.c -- directory block list functions
*
* Copyright 1997 by Theodore Ts'o
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*
*/
#include <stdio.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>
#include <time.h>
#include "ext2_fs.h"
#include "ext2fsP.h"
static int dir_block_cmp(const void *a, const void *b);
/*
* Returns the number of directories in the filesystem as reported by
* the group descriptors. Of course, the group descriptors could be
* wrong!
*/
errcode_t ext2fs_get_num_dirs(ext2_filsys fs, ext2_ino_t *ret_num_dirs)
{
dgrp_t i;
ext2_ino_t num_dirs, max_dirs;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
num_dirs = 0;
max_dirs = fs->super->s_inodes_per_group;
for (i = 0; i < fs->group_desc_count; i++) {
if (fs->group_desc[i].bg_used_dirs_count > max_dirs)
num_dirs += max_dirs / 8;
else
num_dirs += fs->group_desc[i].bg_used_dirs_count;
}
if (num_dirs > fs->super->s_inodes_count)
num_dirs = fs->super->s_inodes_count;
*ret_num_dirs = num_dirs;
return 0;
}
/*
* helper function for making a new directory block list (for
* initialize and copy).
*/
static errcode_t make_dblist(ext2_filsys fs, ext2_ino_t size, ext2_ino_t count,
struct ext2_db_entry *list,
ext2_dblist *ret_dblist)
{
ext2_dblist dblist;
errcode_t retval;
size_t len;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if ((ret_dblist == 0) && fs->dblist &&
(fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
return 0;
retval = ext2fs_get_mem(sizeof(struct ext2_struct_dblist), &dblist);
if (retval)
return retval;
memset(dblist, 0, sizeof(struct ext2_struct_dblist));
dblist->magic = EXT2_ET_MAGIC_DBLIST;
dblist->fs = fs;
if (size)
dblist->size = size;
else {
retval = ext2fs_get_num_dirs(fs, &dblist->size);
if (retval)
goto cleanup;
dblist->size = (dblist->size * 2) + 12;
}
len = (size_t) sizeof(struct ext2_db_entry) * dblist->size;
dblist->count = count;
retval = ext2fs_get_mem(len, &dblist->list);
if (retval)
goto cleanup;
if (list)
memcpy(dblist->list, list, len);
else
memset(dblist->list, 0, len);
if (ret_dblist)
*ret_dblist = dblist;
else
fs->dblist = dblist;
return 0;
cleanup:
ext2fs_free_mem(&dblist);
return retval;
}
/*
* Initialize a directory block list
*/
errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
{
ext2_dblist dblist;
errcode_t retval;
retval = make_dblist(fs, 0, 0, 0, &dblist);
if (retval)
return retval;
dblist->sorted = 1;
if (ret_dblist)
*ret_dblist = dblist;
else
fs->dblist = dblist;
return 0;
}
/*
* Copy a directory block list
*/
errcode_t ext2fs_copy_dblist(ext2_dblist src, ext2_dblist *dest)
{
ext2_dblist dblist;
errcode_t retval;
retval = make_dblist(src->fs, src->size, src->count, src->list,
&dblist);
if (retval)
return retval;
dblist->sorted = src->sorted;
*dest = dblist;
return 0;
}
/*
* Close a directory block list
*
* (moved to closefs.c)
*/
/*
* Add a directory block to the directory block list
*/
errcode_t ext2fs_add_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
int blockcnt)
{
struct ext2_db_entry *new_entry;
errcode_t retval;
unsigned long old_size;
EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
if (dblist->count >= dblist->size) {
old_size = dblist->size * sizeof(struct ext2_db_entry);
dblist->size += 100;
retval = ext2fs_resize_mem(old_size, (size_t) dblist->size *
sizeof(struct ext2_db_entry),
&dblist->list);
if (retval) {
dblist->size -= 100;
return retval;
}
}
new_entry = dblist->list + ( (int) dblist->count++);
new_entry->blk = blk;
new_entry->ino = ino;
new_entry->blockcnt = blockcnt;
dblist->sorted = 0;
return 0;
}
/*
* Change the directory block to the directory block list
*/
errcode_t ext2fs_set_dir_block(ext2_dblist dblist, ext2_ino_t ino, blk_t blk,
int blockcnt)
{
dgrp_t i;
EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
for (i=0; i < dblist->count; i++) {
if ((dblist->list[i].ino != ino) ||
(dblist->list[i].blockcnt != blockcnt))
continue;
dblist->list[i].blk = blk;
dblist->sorted = 0;
return 0;
}
return EXT2_ET_DB_NOT_FOUND;
}
void ext2fs_dblist_sort(ext2_dblist dblist,
int (*sortfunc)(const void *,
const void *))
{
if (!sortfunc)
sortfunc = dir_block_cmp;
qsort(dblist->list, (size_t) dblist->count,
sizeof(struct ext2_db_entry), sortfunc);
dblist->sorted = 1;
}
/*
* This function iterates over the directory block list
*/
errcode_t ext2fs_dblist_iterate(ext2_dblist dblist,
int (*func)(ext2_filsys fs,
struct ext2_db_entry *db_info,
void *priv_data),
void *priv_data)
{
ext2_ino_t i;
int ret;
EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
if (!dblist->sorted)
ext2fs_dblist_sort(dblist, 0);
for (i=0; i < dblist->count; i++) {
ret = (*func)(dblist->fs, &dblist->list[(int)i], priv_data);
if (ret & DBLIST_ABORT)
return 0;
}
return 0;
}
static int dir_block_cmp(const void *a, const void *b)
{
const struct ext2_db_entry *db_a =
(const struct ext2_db_entry *) a;
const struct ext2_db_entry *db_b =
(const struct ext2_db_entry *) b;
if (db_a->blk != db_b->blk)
return (int) (db_a->blk - db_b->blk);
if (db_a->ino != db_b->ino)
return (int) (db_a->ino - db_b->ino);
return (int) (db_a->blockcnt - db_b->blockcnt);
}
int ext2fs_dblist_count(ext2_dblist dblist)
{
return (int) dblist->count;
}