aboutsummaryrefslogtreecommitdiffstats
path: root/fs/ceph/mdsmap.c
blob: 132b64eeecd494b01d224d1d58394db498ed70a9 (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
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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
#include <linux/ceph/ceph_debug.h>

#include <linux/bug.h>
#include <linux/err.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <linux/ceph/mdsmap.h>
#include <linux/ceph/messenger.h>
#include <linux/ceph/decode.h>

#include "super.h"


/*
 * choose a random mds that is "up" (i.e. has a state > 0), or -1.
 */
int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
{
	int n = 0;
	int i;

	/* special case for one mds */
	if (1 == m->m_max_mds && m->m_info[0].state > 0)
		return 0;

	/* count */
	for (i = 0; i < m->m_max_mds; i++)
		if (m->m_info[i].state > 0)
			n++;
	if (n == 0)
		return -1;

	/* pick */
	n = prandom_u32() % n;
	i = 0;
	for (i = 0; n > 0; i++, n--)
		while (m->m_info[i].state <= 0)
			i++;

	return i;
}

/*
 * Decode an MDS map
 *
 * Ignore any fields we don't care about (there are quite a few of
 * them).
 */
struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
{
	struct ceph_mdsmap *m;
	const void *start = *p;
	int i, j, n;
	int err = -EINVAL;
	u16 version;

	m = kzalloc(sizeof(*m), GFP_NOFS);
	if (m == NULL)
		return ERR_PTR(-ENOMEM);

	ceph_decode_16_safe(p, end, version, bad);
	if (version > 3) {
		pr_warning("got mdsmap version %d > 3, failing", version);
		goto bad;
	}

	ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
	m->m_epoch = ceph_decode_32(p);
	m->m_client_epoch = ceph_decode_32(p);
	m->m_last_failure = ceph_decode_32(p);
	m->m_root = ceph_decode_32(p);
	m->m_session_timeout = ceph_decode_32(p);
	m->m_session_autoclose = ceph_decode_32(p);
	m->m_max_file_size = ceph_decode_64(p);
	m->m_max_mds = ceph_decode_32(p);

	m->m_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS);
	if (m->m_info == NULL)
		goto badmem;

	/* pick out active nodes from mds_info (state > 0) */
	n = ceph_decode_32(p);
	for (i = 0; i < n; i++) {
		u64 global_id;
		u32 namelen;
		s32 mds, inc, state;
		u64 state_seq;
		u8 infoversion;
		struct ceph_entity_addr addr;
		u32 num_export_targets;
		void *pexport_targets = NULL;
		struct ceph_timespec laggy_since;
		struct ceph_mds_info *info;

		ceph_decode_need(p, end, sizeof(u64)*2 + 1 + sizeof(u32), bad);
		global_id = ceph_decode_64(p);
		infoversion = ceph_decode_8(p);
		*p += sizeof(u64);
		namelen = ceph_decode_32(p);  /* skip mds name */
		*p += namelen;

		ceph_decode_need(p, end,
				 4*sizeof(u32) + sizeof(u64) +
				 sizeof(addr) + sizeof(struct ceph_timespec),
				 bad);
		mds = ceph_decode_32(p);
		inc = ceph_decode_32(p);
		state = ceph_decode_32(p);
		state_seq = ceph_decode_64(p);
		ceph_decode_copy(p, &addr, sizeof(addr));
		ceph_decode_addr(&addr);
		ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
		*p += sizeof(u32);
		ceph_decode_32_safe(p, end, namelen, bad);
		*p += namelen;
		if (infoversion >= 2) {
			ceph_decode_32_safe(p, end, num_export_targets, bad);
			pexport_targets = *p;
			*p += num_export_targets * sizeof(u32);
		} else {
			num_export_targets = 0;
		}

		dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
		     i+1, n, global_id, mds, inc,
		     ceph_pr_addr(&addr.in_addr),
		     ceph_mds_state_name(state));

		if (mds < 0 || mds >= m->m_max_mds || state <= 0)
			continue;

		info = &m->m_info[mds];
		info->global_id = global_id;
		info->state = state;
		info->addr = addr;
		info->laggy = (laggy_since.tv_sec != 0 ||
			       laggy_since.tv_nsec != 0);
		info->num_export_targets = num_export_targets;
		if (num_export_targets) {
			info->export_targets = kcalloc(num_export_targets,
						       sizeof(u32), GFP_NOFS);
			if (info->export_targets == NULL)
				goto badmem;
			for (j = 0; j < num_export_targets; j++)
				info->export_targets[j] =
				       ceph_decode_32(&pexport_targets);
		} else {
			info->export_targets = NULL;
		}
	}

	/* pg_pools */
	ceph_decode_32_safe(p, end, n, bad);
	m->m_num_data_pg_pools = n;
	m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
	if (!m->m_data_pg_pools)
		goto badmem;
	ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
	for (i = 0; i < n; i++)
		m->m_data_pg_pools[i] = ceph_decode_64(p);
	m->m_cas_pg_pool = ceph_decode_64(p);

	/* ok, we don't care about the rest. */
	dout("mdsmap_decode success epoch %u\n", m->m_epoch);
	return m;

badmem:
	err = -ENOMEM;
bad:
	pr_err("corrupt mdsmap\n");
	print_hex_dump(KERN_DEBUG, "mdsmap: ",
		       DUMP_PREFIX_OFFSET, 16, 1,
		       start, end - start, true);
	ceph_mdsmap_destroy(m);
	return ERR_PTR(err);
}

void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
{
	int i;

	for (i = 0; i < m->m_max_mds; i++)
		kfree(m->m_info[i].export_targets);
	kfree(m->m_info);
	kfree(m->m_data_pg_pools);
	kfree(m);
}