xref: /aosp_15_r20/external/e2fsprogs/lib/ext2fs/unlink.c (revision 6a54128f25917bfc36a8a6e9d722c04a0b4641b6)
1*6a54128fSAndroid Build Coastguard Worker /*
2*6a54128fSAndroid Build Coastguard Worker  * unlink.c --- delete links in a ext2fs directory
3*6a54128fSAndroid Build Coastguard Worker  *
4*6a54128fSAndroid Build Coastguard Worker  * Copyright (C) 1993, 1994, 1997 Theodore Ts'o.
5*6a54128fSAndroid Build Coastguard Worker  *
6*6a54128fSAndroid Build Coastguard Worker  * %Begin-Header%
7*6a54128fSAndroid Build Coastguard Worker  * This file may be redistributed under the terms of the GNU Library
8*6a54128fSAndroid Build Coastguard Worker  * General Public License, version 2.
9*6a54128fSAndroid Build Coastguard Worker  * %End-Header%
10*6a54128fSAndroid Build Coastguard Worker  */
11*6a54128fSAndroid Build Coastguard Worker 
12*6a54128fSAndroid Build Coastguard Worker #include "config.h"
13*6a54128fSAndroid Build Coastguard Worker #include <stdio.h>
14*6a54128fSAndroid Build Coastguard Worker #include <string.h>
15*6a54128fSAndroid Build Coastguard Worker #if HAVE_UNISTD_H
16*6a54128fSAndroid Build Coastguard Worker #include <unistd.h>
17*6a54128fSAndroid Build Coastguard Worker #endif
18*6a54128fSAndroid Build Coastguard Worker 
19*6a54128fSAndroid Build Coastguard Worker #include "ext2_fs.h"
20*6a54128fSAndroid Build Coastguard Worker #include "ext2fs.h"
21*6a54128fSAndroid Build Coastguard Worker 
22*6a54128fSAndroid Build Coastguard Worker struct link_struct  {
23*6a54128fSAndroid Build Coastguard Worker 	const char	*name;
24*6a54128fSAndroid Build Coastguard Worker 	int		namelen;
25*6a54128fSAndroid Build Coastguard Worker 	ext2_ino_t	inode;
26*6a54128fSAndroid Build Coastguard Worker 	int		flags;
27*6a54128fSAndroid Build Coastguard Worker 	struct ext2_dir_entry *prev;
28*6a54128fSAndroid Build Coastguard Worker 	int		done;
29*6a54128fSAndroid Build Coastguard Worker };
30*6a54128fSAndroid Build Coastguard Worker 
31*6a54128fSAndroid Build Coastguard Worker #ifdef __TURBOC__
32*6a54128fSAndroid Build Coastguard Worker  #pragma argsused
33*6a54128fSAndroid Build Coastguard Worker #endif
unlink_proc(struct ext2_dir_entry * dirent,int offset,int blocksize EXT2FS_ATTR ((unused)),char * buf EXT2FS_ATTR ((unused)),void * priv_data)34*6a54128fSAndroid Build Coastguard Worker static int unlink_proc(struct ext2_dir_entry *dirent,
35*6a54128fSAndroid Build Coastguard Worker 		     int	offset,
36*6a54128fSAndroid Build Coastguard Worker 		     int	blocksize EXT2FS_ATTR((unused)),
37*6a54128fSAndroid Build Coastguard Worker 		     char	*buf EXT2FS_ATTR((unused)),
38*6a54128fSAndroid Build Coastguard Worker 		     void	*priv_data)
39*6a54128fSAndroid Build Coastguard Worker {
40*6a54128fSAndroid Build Coastguard Worker 	struct link_struct *ls = (struct link_struct *) priv_data;
41*6a54128fSAndroid Build Coastguard Worker 	struct ext2_dir_entry *prev;
42*6a54128fSAndroid Build Coastguard Worker 
43*6a54128fSAndroid Build Coastguard Worker 	prev = ls->prev;
44*6a54128fSAndroid Build Coastguard Worker 	ls->prev = dirent;
45*6a54128fSAndroid Build Coastguard Worker 
46*6a54128fSAndroid Build Coastguard Worker 	if (ls->name) {
47*6a54128fSAndroid Build Coastguard Worker 		if (ext2fs_dirent_name_len(dirent) != ls->namelen)
48*6a54128fSAndroid Build Coastguard Worker 			return 0;
49*6a54128fSAndroid Build Coastguard Worker 		if (strncmp(ls->name, dirent->name, ext2fs_dirent_name_len(dirent)))
50*6a54128fSAndroid Build Coastguard Worker 			return 0;
51*6a54128fSAndroid Build Coastguard Worker 	}
52*6a54128fSAndroid Build Coastguard Worker 	if (!(ls->flags & EXT2FS_UNLINK_FORCE) && ls->inode) {
53*6a54128fSAndroid Build Coastguard Worker 		if (dirent->inode != ls->inode)
54*6a54128fSAndroid Build Coastguard Worker 			return 0;
55*6a54128fSAndroid Build Coastguard Worker 	} else {
56*6a54128fSAndroid Build Coastguard Worker 		if (!dirent->inode)
57*6a54128fSAndroid Build Coastguard Worker 			return 0;
58*6a54128fSAndroid Build Coastguard Worker 	}
59*6a54128fSAndroid Build Coastguard Worker 
60*6a54128fSAndroid Build Coastguard Worker 	if (offset)
61*6a54128fSAndroid Build Coastguard Worker 		prev->rec_len += dirent->rec_len;
62*6a54128fSAndroid Build Coastguard Worker 	else
63*6a54128fSAndroid Build Coastguard Worker 		dirent->inode = 0;
64*6a54128fSAndroid Build Coastguard Worker 	ls->done++;
65*6a54128fSAndroid Build Coastguard Worker 	return DIRENT_ABORT|DIRENT_CHANGED;
66*6a54128fSAndroid Build Coastguard Worker }
67*6a54128fSAndroid Build Coastguard Worker 
68*6a54128fSAndroid Build Coastguard Worker #ifdef __TURBOC__
69*6a54128fSAndroid Build Coastguard Worker  #pragma argsused
70*6a54128fSAndroid Build Coastguard Worker #endif
ext2fs_unlink(ext2_filsys fs,ext2_ino_t dir,const char * name,ext2_ino_t ino,int flags)71*6a54128fSAndroid Build Coastguard Worker errcode_t ext2fs_unlink(ext2_filsys fs, ext2_ino_t dir,
72*6a54128fSAndroid Build Coastguard Worker 			const char *name, ext2_ino_t ino,
73*6a54128fSAndroid Build Coastguard Worker 			int flags)
74*6a54128fSAndroid Build Coastguard Worker {
75*6a54128fSAndroid Build Coastguard Worker 	errcode_t	retval;
76*6a54128fSAndroid Build Coastguard Worker 	struct link_struct ls;
77*6a54128fSAndroid Build Coastguard Worker 
78*6a54128fSAndroid Build Coastguard Worker 	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
79*6a54128fSAndroid Build Coastguard Worker 
80*6a54128fSAndroid Build Coastguard Worker 	if (!name && !ino)
81*6a54128fSAndroid Build Coastguard Worker 		return EXT2_ET_INVALID_ARGUMENT;
82*6a54128fSAndroid Build Coastguard Worker 
83*6a54128fSAndroid Build Coastguard Worker 	if (!(fs->flags & EXT2_FLAG_RW))
84*6a54128fSAndroid Build Coastguard Worker 		return EXT2_ET_RO_FILSYS;
85*6a54128fSAndroid Build Coastguard Worker 
86*6a54128fSAndroid Build Coastguard Worker 	ls.name = name;
87*6a54128fSAndroid Build Coastguard Worker 	ls.namelen = name ? strlen(name) : 0;
88*6a54128fSAndroid Build Coastguard Worker 	ls.inode = ino;
89*6a54128fSAndroid Build Coastguard Worker 	ls.flags = flags;
90*6a54128fSAndroid Build Coastguard Worker 	ls.done = 0;
91*6a54128fSAndroid Build Coastguard Worker 	ls.prev = 0;
92*6a54128fSAndroid Build Coastguard Worker 
93*6a54128fSAndroid Build Coastguard Worker 	retval = ext2fs_dir_iterate(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY,
94*6a54128fSAndroid Build Coastguard Worker 				    0, unlink_proc, &ls);
95*6a54128fSAndroid Build Coastguard Worker 	if (retval)
96*6a54128fSAndroid Build Coastguard Worker 		return retval;
97*6a54128fSAndroid Build Coastguard Worker 
98*6a54128fSAndroid Build Coastguard Worker 	return (ls.done) ? 0 : EXT2_ET_DIR_NO_SPACE;
99*6a54128fSAndroid Build Coastguard Worker }
100*6a54128fSAndroid Build Coastguard Worker 
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