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 */ 19 int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) 20 { 21 int n = 0; 22 int i; 23 24 /* special case for one mds */ 25 if (1 == m->m_max_mds && m->m_info[0].state > 0) 26 return 0; 27 28 /* count */ 29 for (i = 0; i < m->m_max_mds; i++) 30 if (m->m_info[i].state > 0) 31 n++; 32 if (n == 0) 33 return -1; 34 35 /* pick */ 36 n = prandom_u32() % n; 37 i = 0; 38 for (i = 0; n > 0; i++, n--) 39 while (m->m_info[i].state <= 0) 40 i++; 41 42 return i; 43 } 44 45 /* 46 * Decode an MDS map 47 * 48 * Ignore any fields we don't care about (there are quite a few of 49 * them). 50 */ 51 struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end) 52 { 53 struct ceph_mdsmap *m; 54 const void *start = *p; 55 int i, j, n; 56 int err = -EINVAL; 57 u8 mdsmap_v, mdsmap_cv; 58 59 m = kzalloc(sizeof(*m), GFP_NOFS); 60 if (m == NULL) 61 return ERR_PTR(-ENOMEM); 62 63 ceph_decode_need(p, end, 1 + 1, bad); 64 mdsmap_v = ceph_decode_8(p); 65 mdsmap_cv = ceph_decode_8(p); 66 if (mdsmap_v >= 4) { 67 u32 mdsmap_len; 68 ceph_decode_32_safe(p, end, mdsmap_len, bad); 69 if (end < *p + mdsmap_len) 70 goto bad; 71 end = *p + mdsmap_len; 72 } 73 74 ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad); 75 m->m_epoch = ceph_decode_32(p); 76 m->m_client_epoch = ceph_decode_32(p); 77 m->m_last_failure = ceph_decode_32(p); 78 m->m_root = ceph_decode_32(p); 79 m->m_session_timeout = ceph_decode_32(p); 80 m->m_session_autoclose = ceph_decode_32(p); 81 m->m_max_file_size = ceph_decode_64(p); 82 m->m_max_mds = ceph_decode_32(p); 83 84 m->m_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS); 85 if (m->m_info == NULL) 86 goto badmem; 87 88 /* pick out active nodes from mds_info (state > 0) */ 89 n = ceph_decode_32(p); 90 for (i = 0; i < n; i++) { 91 u64 global_id; 92 u32 namelen; 93 s32 mds, inc, state; 94 u64 state_seq; 95 u8 info_v; 96 void *info_end = NULL; 97 struct ceph_entity_addr addr; 98 u32 num_export_targets; 99 void *pexport_targets = NULL; 100 struct ceph_timespec laggy_since; 101 struct ceph_mds_info *info; 102 103 ceph_decode_need(p, end, sizeof(u64) + 1, bad); 104 global_id = ceph_decode_64(p); 105 info_v= ceph_decode_8(p); 106 if (info_v >= 4) { 107 u32 info_len; 108 u8 info_cv; 109 ceph_decode_need(p, end, 1 + sizeof(u32), bad); 110 info_cv = ceph_decode_8(p); 111 info_len = ceph_decode_32(p); 112 info_end = *p + info_len; 113 if (info_end > end) 114 goto bad; 115 } 116 117 ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad); 118 *p += sizeof(u64); 119 namelen = ceph_decode_32(p); /* skip mds name */ 120 *p += namelen; 121 122 ceph_decode_need(p, end, 123 4*sizeof(u32) + sizeof(u64) + 124 sizeof(addr) + sizeof(struct ceph_timespec), 125 bad); 126 mds = ceph_decode_32(p); 127 inc = ceph_decode_32(p); 128 state = ceph_decode_32(p); 129 state_seq = ceph_decode_64(p); 130 ceph_decode_copy(p, &addr, sizeof(addr)); 131 ceph_decode_addr(&addr); 132 ceph_decode_copy(p, &laggy_since, sizeof(laggy_since)); 133 *p += sizeof(u32); 134 ceph_decode_32_safe(p, end, namelen, bad); 135 *p += namelen; 136 if (info_v >= 2) { 137 ceph_decode_32_safe(p, end, num_export_targets, bad); 138 pexport_targets = *p; 139 *p += num_export_targets * sizeof(u32); 140 } else { 141 num_export_targets = 0; 142 } 143 144 if (info_end && *p != info_end) { 145 if (*p > info_end) 146 goto bad; 147 *p = info_end; 148 } 149 150 dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n", 151 i+1, n, global_id, mds, inc, 152 ceph_pr_addr(&addr.in_addr), 153 ceph_mds_state_name(state)); 154 155 if (mds < 0 || mds >= m->m_max_mds || state <= 0) 156 continue; 157 158 info = &m->m_info[mds]; 159 info->global_id = global_id; 160 info->state = state; 161 info->addr = addr; 162 info->laggy = (laggy_since.tv_sec != 0 || 163 laggy_since.tv_nsec != 0); 164 info->num_export_targets = num_export_targets; 165 if (num_export_targets) { 166 info->export_targets = kcalloc(num_export_targets, 167 sizeof(u32), GFP_NOFS); 168 if (info->export_targets == NULL) 169 goto badmem; 170 for (j = 0; j < num_export_targets; j++) 171 info->export_targets[j] = 172 ceph_decode_32(&pexport_targets); 173 } else { 174 info->export_targets = NULL; 175 } 176 } 177 178 /* pg_pools */ 179 ceph_decode_32_safe(p, end, n, bad); 180 m->m_num_data_pg_pools = n; 181 m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS); 182 if (!m->m_data_pg_pools) 183 goto badmem; 184 ceph_decode_need(p, end, sizeof(u64)*(n+1), bad); 185 for (i = 0; i < n; i++) 186 m->m_data_pg_pools[i] = ceph_decode_64(p); 187 m->m_cas_pg_pool = ceph_decode_64(p); 188 189 /* ok, we don't care about the rest. */ 190 *p = end; 191 dout("mdsmap_decode success epoch %u\n", m->m_epoch); 192 return m; 193 194 badmem: 195 err = -ENOMEM; 196 bad: 197 pr_err("corrupt mdsmap\n"); 198 print_hex_dump(KERN_DEBUG, "mdsmap: ", 199 DUMP_PREFIX_OFFSET, 16, 1, 200 start, end - start, true); 201 ceph_mdsmap_destroy(m); 202 return ERR_PTR(err); 203 } 204 205 void ceph_mdsmap_destroy(struct ceph_mdsmap *m) 206 { 207 int i; 208 209 for (i = 0; i < m->m_max_mds; i++) 210 kfree(m->m_info[i].export_targets); 211 kfree(m->m_info); 212 kfree(m->m_data_pg_pools); 213 kfree(m); 214 } 215