e2fsprogs/lib/ext2fs/dblist.c

176 lines
3.4 KiB
C

/*
* 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>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <linux/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, ino_t *ret_num_dirs)
{
int i;
ino_t num_dirs;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
num_dirs = 0;
for (i = 0; i < fs->group_desc_count; i++)
num_dirs += fs->group_desc[i].bg_used_dirs_count;
*ret_num_dirs = num_dirs;
return 0;
}
/*
* Initialize a directory block list
*/
errcode_t ext2fs_init_dblist(ext2_filsys fs, ext2_dblist *ret_dblist)
{
ext2_dblist dblist;
errcode_t retval;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if ((ret_dblist == 0) && fs->dblist &&
(fs->dblist->magic == EXT2_ET_MAGIC_DBLIST))
return 0;
dblist = malloc(sizeof(struct ext2_struct_dblist));
if (!dblist)
return ENOMEM;
memset(dblist, 0, sizeof(struct ext2_struct_dblist));
dblist->magic = EXT2_ET_MAGIC_DBLIST;
dblist->fs = fs;
retval = ext2fs_get_num_dirs(fs, &dblist->size);
if (retval)
goto cleanup;
dblist->count = 0;
dblist->sorted = 1;
dblist->list = malloc(sizeof(struct ext2_db_entry) * dblist->size);
if (dblist->list == NULL) {
retval = ENOMEM;
goto cleanup;
}
if (ret_dblist)
*ret_dblist = dblist;
else
fs->dblist = dblist;
return 0;
cleanup:
if (dblist)
free(dblist);
return retval;
}
/*
* 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, ino_t ino, blk_t blk,
int blockcnt)
{
struct ext2_db_entry *nlist, *new;
EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
if (dblist->count >= dblist->size) {
dblist->size += 100;
nlist = realloc(dblist->list,
dblist->size * sizeof(struct ext2_db_entry));
if (nlist == 0) {
dblist->size -= 100;
return ENOMEM;
}
dblist->list = nlist;
}
new = dblist->list + dblist->count++;
new->blk = blk;
new->ino = ino;
new->blockcnt = blockcnt;
dblist->sorted = 0;
return 0;
}
/*
* 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 *private),
void *private)
{
ino_t i;
int ret;
EXT2_CHECK_MAGIC(dblist, EXT2_ET_MAGIC_DBLIST);
if (!dblist->sorted) {
qsort(dblist->list, dblist->count,
sizeof(struct ext2_db_entry), dir_block_cmp);
dblist->sorted = 1;
}
for (i=0; i < dblist->count; i++) {
ret = (*func)(dblist->fs, &dblist->list[i], private);
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 (db_a->blk - db_b->blk);
if (db_a->ino != db_b->ino)
return (db_a->ino - db_b->ino);
return (db_a->blockcnt - db_b->blockcnt);
}