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
unlink_proc(struct ext2_dir_entry * dirent,int offset,int blocksize EXT2FS_ATTR ((unused)),char * buf EXT2FS_ATTR ((unused)),void * priv_data)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
ext2fs_unlink(ext2_filsys fs,ext2_ino_t dir,const char * name,ext2_ino_t ino,int flags EXT2FS_ATTR ((unused)))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