blob: f45acf7385bff88083780de96fb998d77ab60dfc (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
|
/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* hardlink.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "config.h"
#include "fstree.h"
#include <string.h>
#include <stdlib.h>
#include <errno.h>
tree_node_t *fstree_add_hard_link(fstree_t *fs, const char *path,
const char *target)
{
struct stat sb;
tree_node_t *n;
memset(&sb, 0, sizeof(sb));
sb.st_mode = S_IFLNK | 0777;
n = fstree_add_generic(fs, path, &sb, target);
if (n != NULL) {
if (canonicalize_name(n->data.target)) {
free(n);
errno = EINVAL;
return NULL;
}
n->mode = FSTREE_MODE_HARD_LINK;
}
return n;
}
int fstree_resolve_hard_link(fstree_t *fs, tree_node_t *node)
{
tree_node_t *start = node;
while (node->mode == FSTREE_MODE_HARD_LINK ||
node->mode == FSTREE_MODE_HARD_LINK_RESOLVED) {
if (node->mode == FSTREE_MODE_HARD_LINK_RESOLVED) {
node = node->data.target_node;
} else {
node = fstree_get_node_by_path(fs, fs->root,
node->data.target,
false, false);
if (node == NULL)
return -1;
}
if (node == start) {
errno = EMLINK;
return -1;
}
}
if (S_ISDIR(node->mode)) {
errno = EPERM;
return -1;
}
if (node->link_count == 0xFFFFFFFF) {
errno = EMLINK;
return -1;
}
start->mode = FSTREE_MODE_HARD_LINK_RESOLVED;
start->data.target_node = node;
node->link_count++;
return 0;
}
|