1 #include "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 "mdsmap.h" 10 #include "messenger.h" 11 #include "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 int i, j, n; 53 int err = -EINVAL; 54 u16 version; 55 56 m = kzalloc(sizeof(*m), GFP_NOFS); 57 if (m == NULL) 58 return ERR_PTR(-ENOMEM); 59 60 ceph_decode_16_safe(p, end, version, bad); 61 62 ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad); 63 ceph_decode_32(p, m->m_epoch); 64 ceph_decode_32(p, m->m_client_epoch); 65 ceph_decode_32(p, m->m_last_failure); 66 ceph_decode_32(p, m->m_root); 67 ceph_decode_32(p, m->m_session_timeout); 68 ceph_decode_32(p, m->m_session_autoclose); 69 ceph_decode_64(p, m->m_max_file_size); 70 ceph_decode_32(p, m->m_max_mds); 71 72 m->m_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS); 73 if (m->m_info == NULL) 74 goto badmem; 75 76 /* pick out active nodes from mds_info (state > 0) */ 77 ceph_decode_32(p, n); 78 for (i = 0; i < n; i++) { 79 u32 namelen; 80 s32 mds, inc, state; 81 u64 state_seq; 82 u8 infoversion; 83 struct ceph_entity_addr addr; 84 u32 num_export_targets; 85 void *pexport_targets = NULL; 86 87 ceph_decode_need(p, end, sizeof(addr) + 1 + sizeof(u32), bad); 88 ceph_decode_copy(p, &addr, sizeof(addr)); 89 ceph_decode_8(p, infoversion); 90 ceph_decode_32(p, namelen); /* skip mds name */ 91 *p += namelen; 92 93 ceph_decode_need(p, end, 94 4*sizeof(u32) + sizeof(u64) + 95 sizeof(addr) + sizeof(struct ceph_timespec), 96 bad); 97 ceph_decode_32(p, mds); 98 ceph_decode_32(p, inc); 99 ceph_decode_32(p, state); 100 ceph_decode_64(p, state_seq); 101 *p += sizeof(addr); 102 *p += sizeof(struct ceph_timespec); 103 *p += sizeof(u32); 104 ceph_decode_32_safe(p, end, namelen, bad); 105 *p += namelen; 106 if (infoversion >= 2) { 107 ceph_decode_32_safe(p, end, num_export_targets, bad); 108 pexport_targets = *p; 109 *p += num_export_targets * sizeof(u32); 110 } else { 111 num_export_targets = 0; 112 } 113 114 dout("mdsmap_decode %d/%d mds%d.%d %s %s\n", 115 i+1, n, mds, inc, pr_addr(&addr.in_addr), 116 ceph_mds_state_name(state)); 117 if (mds >= 0 && mds < m->m_max_mds && state > 0) { 118 m->m_info[mds].state = state; 119 m->m_info[mds].addr = addr; 120 m->m_info[mds].num_export_targets = num_export_targets; 121 if (num_export_targets) { 122 m->m_info[mds].export_targets = 123 kcalloc(num_export_targets, sizeof(u32), 124 GFP_NOFS); 125 for (j = 0; j < num_export_targets; j++) 126 ceph_decode_32(&pexport_targets, 127 m->m_info[mds].export_targets[j]); 128 } else { 129 m->m_info[mds].export_targets = NULL; 130 } 131 } 132 } 133 134 /* pg_pools */ 135 ceph_decode_32_safe(p, end, n, bad); 136 m->m_num_data_pg_pools = n; 137 m->m_data_pg_pools = kcalloc(n, sizeof(u32), GFP_NOFS); 138 if (!m->m_data_pg_pools) 139 goto badmem; 140 ceph_decode_need(p, end, sizeof(u32)*(n+1), bad); 141 for (i = 0; i < n; i++) 142 ceph_decode_32(p, m->m_data_pg_pools[i]); 143 ceph_decode_32(p, m->m_cas_pg_pool); 144 145 /* ok, we don't care about the rest. */ 146 dout("mdsmap_decode success epoch %u\n", m->m_epoch); 147 return m; 148 149 badmem: 150 err = -ENOMEM; 151 bad: 152 pr_err("corrupt mdsmap\n"); 153 ceph_mdsmap_destroy(m); 154 return ERR_PTR(-EINVAL); 155 } 156 157 void ceph_mdsmap_destroy(struct ceph_mdsmap *m) 158 { 159 int i; 160 161 for (i = 0; i < m->m_max_mds; i++) 162 kfree(m->m_info[i].export_targets); 163 kfree(m->m_info); 164 kfree(m->m_data_pg_pools); 165 kfree(m); 166 } 167