1 #include <linux/ceph/ceph_debug.h>
2
3 #include <linux/bug.h>
4 #include <linux/err.h>
5 #include <linux/random.h>
6 #include <linux/slab.h>
7 #include <linux/types.h>
8
9 #include <linux/ceph/mdsmap.h>
10 #include <linux/ceph/messenger.h>
11 #include <linux/ceph/decode.h>
12
13 #include "super.h"
14
15
16 /*
17 * choose a random mds that is "up" (i.e. has a state > 0), or -1.
18 */
ceph_mdsmap_get_random_mds(struct ceph_mdsmap * m)19 int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
20 {
21 int n = 0;
22 int i;
23 char r;
24
25 /* count */
26 for (i = 0; i < m->m_max_mds; i++)
27 if (m->m_info[i].state > 0)
28 n++;
29 if (n == 0)
30 return -1;
31
32 /* pick */
33 get_random_bytes(&r, 1);
34 n = r % n;
35 i = 0;
36 for (i = 0; n > 0; i++, n--)
37 while (m->m_info[i].state <= 0)
38 i++;
39
40 return i;
41 }
42
43 /*
44 * Decode an MDS map
45 *
46 * Ignore any fields we don't care about (there are quite a few of
47 * them).
48 */
ceph_mdsmap_decode(void ** p,void * end)49 struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
50 {
51 struct ceph_mdsmap *m;
52 const void *start = *p;
53 int i, j, n;
54 int err = -EINVAL;
55 u16 version;
56
57 m = kzalloc(sizeof(*m), GFP_NOFS);
58 if (m == NULL)
59 return ERR_PTR(-ENOMEM);
60
61 ceph_decode_16_safe(p, end, version, bad);
62
63 ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
64 m->m_epoch = ceph_decode_32(p);
65 m->m_client_epoch = ceph_decode_32(p);
66 m->m_last_failure = ceph_decode_32(p);
67 m->m_root = ceph_decode_32(p);
68 m->m_session_timeout = ceph_decode_32(p);
69 m->m_session_autoclose = ceph_decode_32(p);
70 m->m_max_file_size = ceph_decode_64(p);
71 m->m_max_mds = ceph_decode_32(p);
72
73 m->m_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS);
74 if (m->m_info == NULL)
75 goto badmem;
76
77 /* pick out active nodes from mds_info (state > 0) */
78 n = ceph_decode_32(p);
79 for (i = 0; i < n; i++) {
80 u64 global_id;
81 u32 namelen;
82 s32 mds, inc, state;
83 u64 state_seq;
84 u8 infoversion;
85 struct ceph_entity_addr addr;
86 u32 num_export_targets;
87 void *pexport_targets = NULL;
88 struct ceph_timespec laggy_since;
89
90 ceph_decode_need(p, end, sizeof(u64)*2 + 1 + sizeof(u32), bad);
91 global_id = ceph_decode_64(p);
92 infoversion = ceph_decode_8(p);
93 *p += sizeof(u64);
94 namelen = ceph_decode_32(p); /* skip mds name */
95 *p += namelen;
96
97 ceph_decode_need(p, end,
98 4*sizeof(u32) + sizeof(u64) +
99 sizeof(addr) + sizeof(struct ceph_timespec),
100 bad);
101 mds = ceph_decode_32(p);
102 inc = ceph_decode_32(p);
103 state = ceph_decode_32(p);
104 state_seq = ceph_decode_64(p);
105 ceph_decode_copy(p, &addr, sizeof(addr));
106 ceph_decode_addr(&addr);
107 ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
108 *p += sizeof(u32);
109 ceph_decode_32_safe(p, end, namelen, bad);
110 *p += namelen;
111 if (infoversion >= 2) {
112 ceph_decode_32_safe(p, end, num_export_targets, bad);
113 pexport_targets = *p;
114 *p += num_export_targets * sizeof(u32);
115 } else {
116 num_export_targets = 0;
117 }
118
119 dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
120 i+1, n, global_id, mds, inc,
121 ceph_pr_addr(&addr.in_addr),
122 ceph_mds_state_name(state));
123 if (mds >= 0 && mds < m->m_max_mds && state > 0) {
124 m->m_info[mds].global_id = global_id;
125 m->m_info[mds].state = state;
126 m->m_info[mds].addr = addr;
127 m->m_info[mds].laggy =
128 (laggy_since.tv_sec != 0 ||
129 laggy_since.tv_nsec != 0);
130 m->m_info[mds].num_export_targets = num_export_targets;
131 if (num_export_targets) {
132 m->m_info[mds].export_targets =
133 kcalloc(num_export_targets, sizeof(u32),
134 GFP_NOFS);
135 for (j = 0; j < num_export_targets; j++)
136 m->m_info[mds].export_targets[j] =
137 ceph_decode_32(&pexport_targets);
138 } else {
139 m->m_info[mds].export_targets = NULL;
140 }
141 }
142 }
143
144 /* pg_pools */
145 ceph_decode_32_safe(p, end, n, bad);
146 m->m_num_data_pg_pools = n;
147 m->m_data_pg_pools = kcalloc(n, sizeof(u32), GFP_NOFS);
148 if (!m->m_data_pg_pools)
149 goto badmem;
150 ceph_decode_need(p, end, sizeof(u32)*(n+1), bad);
151 for (i = 0; i < n; i++)
152 m->m_data_pg_pools[i] = ceph_decode_32(p);
153 m->m_cas_pg_pool = ceph_decode_32(p);
154
155 /* ok, we don't care about the rest. */
156 dout("mdsmap_decode success epoch %u\n", m->m_epoch);
157 return m;
158
159 badmem:
160 err = -ENOMEM;
161 bad:
162 pr_err("corrupt mdsmap\n");
163 print_hex_dump(KERN_DEBUG, "mdsmap: ",
164 DUMP_PREFIX_OFFSET, 16, 1,
165 start, end - start, true);
166 ceph_mdsmap_destroy(m);
167 return ERR_PTR(-EINVAL);
168 }
169
ceph_mdsmap_destroy(struct ceph_mdsmap * m)170 void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
171 {
172 int i;
173
174 for (i = 0; i < m->m_max_mds; i++)
175 kfree(m->m_info[i].export_targets);
176 kfree(m->m_info);
177 kfree(m->m_data_pg_pools);
178 kfree(m);
179 }
180