LXR busybox/e2fsprogs/old_e2fsprogs/ext2fs/valid

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * valid_blk.c --- does the inode have valid blocks?
   4 *
   5 * Copyright 1997 by Theodore Ts'o
   6 *
   7 * %Begin-Header%
   8 * This file may be redistributed under the terms of the GNU Public
   9 * License.
  10 * %End-Header%
  11 *
  12 */
  13
  14#include <stdio.h>
  15#if HAVE_UNISTD_H
  16#include <unistd.h>
  17#endif
  18#include <string.h>
  19#include <time.h>
  20
  21#include "ext2_fs.h"
  22#include "ext2fs.h"
  23
  24/*
  25 * This function returns 1 if the inode's block entries actually
  26 * contain block entries.
  27 */
  28int ext2fs_inode_has_valid_blocks(struct ext2_inode *inode)
  29{
  30        /*
  31         * Only directories, regular files, and some symbolic links
  32         * have valid block entries.
  33         */
  34        if (!LINUX_S_ISDIR(inode->i_mode) && !LINUX_S_ISREG(inode->i_mode) &&
  35            !LINUX_S_ISLNK(inode->i_mode))
  36                return 0;
  37
  38        /*
  39         * If the symbolic link is a "fast symlink", then the symlink
  40         * target is stored in the block entries.
  41         */
  42        if (LINUX_S_ISLNK (inode->i_mode)) {
  43                if (inode->i_file_acl == 0) {
  44                        /* With no EA block, we can rely on i_blocks */
  45                        if (inode->i_blocks == 0)
  46                                return 0;
  47                } else {
  48                        /* With an EA block, life gets more tricky */
  49                        if (inode->i_size >= EXT2_N_BLOCKS*4)
  50                                return 1; /* definitely using i_block[] */
  51                        if (inode->i_size > 4 && inode->i_block[1] == 0)
  52                                return 1; /* definitely using i_block[] */
  53                        return 0; /* Probably a fast symlink */
  54                }
  55        }
  56        return 1;
  57}
  58