unlink.c revision 7e5a86a66044c4bf4021d1e2900a8748011f17b5 
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 Public
8 * License.
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
21struct 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
33static 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
70errcode_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