blob: 08b2e9673846eb2610eed0228b793c54d2d2d55b [file] [log] [blame]
"Robert P. J. Day"63fc1a92006-07-02 19:47:05 +00001/* vi: set sw=4 ts=4: */
Mike Frysinger1fd98e02005-05-09 22:10:42 +00002/*
3 * link.c --- create links in a ext2fs directory
Tim Rikerc1ef7bd2006-01-25 00:08:53 +00004 *
Mike Frysinger1fd98e02005-05-09 22:10:42 +00005 * Copyright (C) 1993, 1994 Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Public
9 * License.
10 * %End-Header%
11 */
12
13#include <stdio.h>
14#include <string.h>
15#if HAVE_UNISTD_H
16#include <unistd.h>
17#endif
18
19#include "ext2_fs.h"
20#include "ext2fs.h"
21
22struct link_struct {
23 const char *name;
24 int namelen;
25 ext2_ino_t inode;
26 int flags;
27 int done;
28 struct ext2_super_block *sb;
Tim Rikerc1ef7bd2006-01-25 00:08:53 +000029};
Mike Frysinger1fd98e02005-05-09 22:10:42 +000030
31static int link_proc(struct ext2_dir_entry *dirent,
32 int offset,
33 int blocksize,
34 char *buf,
35 void *priv_data)
36{
37 struct link_struct *ls = (struct link_struct *) priv_data;
38 struct ext2_dir_entry *next;
39 int rec_len, min_rec_len;
40 int ret = 0;
41
42 rec_len = EXT2_DIR_REC_LEN(ls->namelen);
43
44 /*
45 * See if the following directory entry (if any) is unused;
46 * if so, absorb it into this one.
47 */
48 next = (struct ext2_dir_entry *) (buf + offset + dirent->rec_len);
49 if ((offset + dirent->rec_len < blocksize - 8) &&
50 (next->inode == 0) &&
51 (offset + dirent->rec_len + next->rec_len <= blocksize)) {
52 dirent->rec_len += next->rec_len;
53 ret = DIRENT_CHANGED;
54 }
55
56 /*
57 * If the directory entry is used, see if we can split the
58 * directory entry to make room for the new name. If so,
59 * truncate it and return.
60 */
61 if (dirent->inode) {
62 min_rec_len = EXT2_DIR_REC_LEN(dirent->name_len & 0xFF);
63 if (dirent->rec_len < (min_rec_len + rec_len))
64 return ret;
65 rec_len = dirent->rec_len - min_rec_len;
66 dirent->rec_len = min_rec_len;
67 next = (struct ext2_dir_entry *) (buf + offset +
68 dirent->rec_len);
69 next->inode = 0;
70 next->name_len = 0;
71 next->rec_len = rec_len;
72 return DIRENT_CHANGED;
73 }
74
75 /*
76 * If we get this far, then the directory entry is not used.
77 * See if we can fit the request entry in. If so, do it.
78 */
79 if (dirent->rec_len < rec_len)
80 return ret;
81 dirent->inode = ls->inode;
82 dirent->name_len = ls->namelen;
83 strncpy(dirent->name, ls->name, ls->namelen);
84 if (ls->sb->s_feature_incompat & EXT2_FEATURE_INCOMPAT_FILETYPE)
85 dirent->name_len |= (ls->flags & 0x7) << 8;
86
87 ls->done++;
88 return DIRENT_ABORT|DIRENT_CHANGED;
89}
90
91/*
92 * Note: the low 3 bits of the flags field are used as the directory
93 * entry filetype.
94 */
95#ifdef __TURBOC__
Mike Frysingerf8855132006-03-28 02:35:56 +000096# pragma argsused
Mike Frysinger1fd98e02005-05-09 22:10:42 +000097#endif
Tim Rikerc1ef7bd2006-01-25 00:08:53 +000098errcode_t ext2fs_link(ext2_filsys fs, ext2_ino_t dir, const char *name,
Mike Frysinger1fd98e02005-05-09 22:10:42 +000099 ext2_ino_t ino, int flags)
100{
101 errcode_t retval;
102 struct link_struct ls;
103 struct ext2_inode inode;
104
105 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
106
107 if (!(fs->flags & EXT2_FLAG_RW))
108 return EXT2_ET_RO_FILSYS;
109
110 ls.name = name;
111 ls.namelen = name ? strlen(name) : 0;
112 ls.inode = ino;
113 ls.flags = flags;
114 ls.done = 0;
115 ls.sb = fs->super;
116
117 retval = ext2fs_dir_iterate(fs, dir, DIRENT_FLAG_INCLUDE_EMPTY,
118 0, link_proc, &ls);
119 if (retval)
120 return retval;
121
122 if (!ls.done)
123 return EXT2_ET_DIR_NO_SPACE;
124
125 if ((retval = ext2fs_read_inode(fs, dir, &inode)) != 0)
126 return retval;
127
128 if (inode.i_flags & EXT2_INDEX_FL) {
129 inode.i_flags &= ~EXT2_INDEX_FL;
130 if ((retval = ext2fs_write_inode(fs, dir, &inode)) != 0)
131 return retval;
132 }
133
134 return 0;
135}