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 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 */ 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 } 169 170 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