busybox/e2fsprogs/ext2fs/valid_blk.c

58 lines
1.3 KiB
C

/* vi: set sw=4 ts=4: */
/*
* valid_blk.c --- does the inode have valid blocks?
*
* 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 "ext2fs.h"
/*
* This function returns 1 if the inode's block entries actually
* contain block entries.
*/
int ext2fs_inode_has_valid_blocks(struct ext2_inode *inode)
{
/*
* Only directories, regular files, and some symbolic links
* have valid block entries.
*/
if (!LINUX_S_ISDIR(inode->i_mode) && !LINUX_S_ISREG(inode->i_mode) &&
!LINUX_S_ISLNK(inode->i_mode))
return 0;
/*
* If the symbolic link is a "fast symlink", then the symlink
* target is stored in the block entries.
*/
if (LINUX_S_ISLNK (inode->i_mode)) {
if (inode->i_file_acl == 0) {
/* With no EA block, we can rely on i_blocks */
if (inode->i_blocks == 0)
return 0;
} else {
/* With an EA block, life gets more tricky */
if (inode->i_size >= EXT2_N_BLOCKS*4)
return 1; /* definitely using i_block[] */
if (inode->i_size > 4 && inode->i_block[1] == 0)
return 1; /* definitely using i_block[] */
return 0; /* Probably a fast symlink */
}
}
return 1;
}