aboutsummaryrefslogtreecommitdiff
path: root/sys/contrib/openzfs/lib/libzfsbootenv/lzbe_device.c
blob: 2d9c7b749ef2c4a1b5fea366e6d9299b4fd6e5c9 (plain) (blame)
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
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */
/*
 * Copyright 2020 Toomas Soome <tsoome@me.com>
 */

#include <sys/types.h>
#include <string.h>
#include <libzfs.h>
#include <libzfsbootenv.h>
#include <sys/zfs_bootenv.h>
#include <sys/vdev_impl.h>

/*
 * Store device name to zpool label bootenv area.
 * This call will set bootenv version to VB_NVLIST, if bootenv currently
 * does contain other version, then old data will be replaced.
 */
int
lzbe_set_boot_device(const char *pool, lzbe_flags_t flag, const char *device)
{
	libzfs_handle_t *hdl;
	zpool_handle_t *zphdl;
	nvlist_t *nv;
	char *descriptor;
	uint64_t version;
	int rv = -1;

	if (pool == NULL || *pool == '\0')
		return (rv);

	if ((hdl = libzfs_init()) == NULL)
		return (rv);

	zphdl = zpool_open(hdl, pool);
	if (zphdl == NULL) {
		libzfs_fini(hdl);
		return (rv);
	}

	switch (flag) {
	case lzbe_add:
		rv = zpool_get_bootenv(zphdl, &nv);
		if (rv == 0) {
			/*
			 * We got the nvlist, check for version.
			 * if version is missing or is not VB_NVLIST,
			 * create new list.
			 */
			rv = nvlist_lookup_uint64(nv, BOOTENV_VERSION,
			    &version);
			if (rv == 0 && version == VB_NVLIST)
				break;

			/* Drop this nvlist */
			fnvlist_free(nv);
		}
		fallthrough;
	case lzbe_replace:
		nv = fnvlist_alloc();
		break;
	default:
		return (rv);
	}

	/* version is mandatory */
	fnvlist_add_uint64(nv, BOOTENV_VERSION, VB_NVLIST);

	/*
	 * If device name is empty, remove boot device configuration.
	 */
	if ((device == NULL || *device == '\0')) {
		if (nvlist_exists(nv, OS_BOOTONCE))
			fnvlist_remove(nv, OS_BOOTONCE);
	} else {
		/*
		 * Use device name directly if it does start with
		 * prefix "zfs:". Otherwise, add prefix and suffix.
		 */
		if (strncmp(device, "zfs:", 4) == 0) {
			fnvlist_add_string(nv, OS_BOOTONCE, device);
		} else {
			if (asprintf(&descriptor, "zfs:%s:", device) > 0) {
				fnvlist_add_string(nv, OS_BOOTONCE, descriptor);
				free(descriptor);
			} else
				rv = ENOMEM;
		}
	}

	rv = zpool_set_bootenv(zphdl, nv);
	if (rv != 0)
		fprintf(stderr, "%s\n", libzfs_error_description(hdl));

	fnvlist_free(nv);
	zpool_close(zphdl);
	libzfs_fini(hdl);
	return (rv);
}

/*
 * Return boot device name from bootenv, if set.
 */
int
lzbe_get_boot_device(const char *pool, char **device)
{
	libzfs_handle_t *hdl;
	zpool_handle_t *zphdl;
	nvlist_t *nv;
	char *val;
	int rv = -1;

	if (pool == NULL || *pool == '\0' || device == NULL)
		return (rv);

	if ((hdl = libzfs_init()) == NULL)
		return (rv);

	zphdl = zpool_open(hdl, pool);
	if (zphdl == NULL) {
		libzfs_fini(hdl);
		return (rv);
	}

	rv = zpool_get_bootenv(zphdl, &nv);
	if (rv == 0) {
		rv = nvlist_lookup_string(nv, OS_BOOTONCE, &val);
		if (rv == 0) {
			/*
			 * zfs device descriptor is in form of "zfs:dataset:",
			 * we only do need dataset name.
			 */
			if (strncmp(val, "zfs:", 4) == 0) {
				val += 4;
				val = strdup(val);
				if (val != NULL) {
					size_t len = strlen(val);

					if (val[len - 1] == ':')
						val[len - 1] = '\0';
					*device = val;
				} else {
					rv = ENOMEM;
				}
			} else {
				rv = EINVAL;
			}
		}
		nvlist_free(nv);
	}

	zpool_close(zphdl);
	libzfs_fini(hdl);
	return (rv);
}