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      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 
    100