lib/ext2fs/unlink.c

   1 /*
   2  * unlink.c --- delete links in a ext2fs directory
   3  *
   4  * Copyright (C) 1993, 1994, 1997 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 #include <stdio.h>
  13 #include <string.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17
  18 #include "ext2_fs.h"
  19 #include "ext2fs.h"
  20
  21 struct link_struct  {
  22         const char      *name;
  23         int             namelen;
  24         ext2_ino_t      inode;
  25         int             flags;
  26         struct ext2_dir_entry *prev;
  27         int             done;
  28 };
  29
  30 #ifdef __TURBOC__
  31  #pragma argsused
  32 #endif
  33 static int unlink_proc(struct ext2_dir_entry *dirent,
  34                      int        offset,
  35                      int        blocksize EXT2FS_ATTR((unused)),
  36                      char       *buf EXT2FS_ATTR((unused)),
  37                      void       *priv_data)
  38 {
  39         struct link_struct *ls = (struct link_struct *) priv_data;
  40         struct ext2_dir_entry *prev;
  41
  42         prev = ls->prev;
  43         ls->prev = dirent;
  44
  45         if (ls->name) {
  46                 if ((dirent->name_len & 0xFF) != ls->namelen)
  47                         return 0;
  48                 if (strncmp(ls->name, dirent->name, dirent->name_len & 0xFF))
  49                         return 0;
  50         }
  51         if (ls->inode) {
  52                 if (dirent->inode != ls->inode)
  53                         return 0;
  54         } else {
  55                 if (!dirent->inode)
  56                         return 0;
  57         }
  58
  59         if (offset)
  60                 prev->rec_len += dirent->rec_len;
  61         else
  62                 dirent->inode = 0;
  63         ls->done++;
  64         return DIRENT_ABORT|DIRENT_CHANGED;
  65 }
  66
  67 #ifdef __TURBOC__
  68  #pragma argsused
  69 #endif
  70 errcode_t ext2fs_unlink(ext2_filsys fs, ext2_ino_t dir,
  71                         const char *name, ext2_ino_t ino,
  72                         int flags EXT2FS_ATTR((unused)))
  73 {
  74         errcode_t       retval;
  75         struct link_struct ls;
  76
  77         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  78
  79         if (!name && !ino)
  80                 return EXT2_ET_INVALID_ARGUMENT;
  81
  82         if (!(fs->flags & EXT2_FLAG_RW))
  83                 return EXT2_ET_RO_FILSYS;
  84
  85         ls.name = name;
  86         ls.namelen = name ? strlen(name) : 0;
  87         ls.inode = ino;
  88         ls.flags = 0;
  89         ls.done = 0;
  90         ls.prev = 0;
  91
  92         retval = ext2fs_dir_iterate(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY,
  93                                     0, unlink_proc, &ls);
  94         if (retval)
  95                 return retval;
  96
  97         return (ls.done) ? 0 : EXT2_ET_DIR_NO_SPACE;
  98 }
  99