LXR busybox/e2fsprogs/old_e2fsprogs/ext2fs/unlink.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * unlink.c --- delete links in a ext2fs directory
   4 *
   5 * Copyright (C) 1993, 1994, 1997 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#include <stdio.h>
  14#include <string.h>
  15#if HAVE_UNISTD_H
  16#include <unistd.h>
  17#endif
  18
  19#include "ext2_fs.h"
  20#include "ext2fs.h"
  21
  22struct link_struct  {
  23        const char      *name;
  24        int             namelen;
  25        ext2_ino_t      inode;
  26        int             flags;
  27        struct ext2_dir_entry *prev;
  28        int             done;
  29};
  30
  31#ifdef __TURBOC__
  32# pragma argsused
  33#endif
  34static int unlink_proc(struct ext2_dir_entry *dirent,
  35                     int        offset EXT2FS_ATTR((unused)),
  36                     int        blocksize EXT2FS_ATTR((unused)),
  37                     char       *buf EXT2FS_ATTR((unused)),
  38                     void       *priv_data)
  39{
  40        struct link_struct *ls = (struct link_struct *) priv_data;
  41        struct ext2_dir_entry *prev;
  42
  43        prev = ls->prev;
  44        ls->prev = dirent;
  45
  46        if (ls->name) {
  47                if ((dirent->name_len & 0xFF) != ls->namelen)
  48                        return 0;
  49                if (strncmp(ls->name, dirent->name, dirent->name_len & 0xFF))
  50                        return 0;
  51        }
  52        if (ls->inode) {
  53                if (dirent->inode != ls->inode)
  54                        return 0;
  55        } else {
  56                if (!dirent->inode)
  57                        return 0;
  58        }
  59
  60        if (prev)
  61                prev->rec_len += dirent->rec_len;
  62        else
  63                dirent->inode = 0;
  64        ls->done++;
  65        return DIRENT_ABORT|DIRENT_CHANGED;
  66}
  67
  68#ifdef __TURBOC__
  69 #pragma argsused
  70#endif
  71errcode_t ext2fs_unlink(ext2_filsys fs, ext2_ino_t dir,
  72                        const char *name, ext2_ino_t ino,
  73                        int flags EXT2FS_ATTR((unused)))
  74{
  75        errcode_t       retval;
  76        struct link_struct ls;
  77
  78        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  79
  80        if (!name && !ino)
  81                return EXT2_ET_INVALID_ARGUMENT;
  82
  83        if (!(fs->flags & EXT2_FLAG_RW))
  84                return EXT2_ET_RO_FILSYS;
  85
  86        ls.name = name;
  87        ls.namelen = name ? strlen(name) : 0;
  88        ls.inode = ino;
  89        ls.flags = 0;
  90        ls.done = 0;
  91        ls.prev = 0;
  92
  93        retval = ext2fs_dir_iterate(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY,
  94                                    0, unlink_proc, &ls);
  95        if (retval)
  96                return retval;
  97
  98        return (ls.done) ? 0 : EXT2_ET_DIR_NO_SPACE;
  99}
 100