fs/ceph/mdsmap.c

   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 #define __decode_and_drop_type(p, end, type, bad)               \
  46         do {                                                    \
  47                 if (*p + sizeof(type) > end)                    \
  48                         goto bad;                               \
  49                 *p += sizeof(type);                             \
  50         } while (0)
  51
  52 #define __decode_and_drop_set(p, end, type, bad)                \
  53         do {                                                    \
  54                 u32 n;                                          \
  55                 size_t need;                                    \
  56                 ceph_decode_32_safe(p, end, n, bad);            \
  57                 need = sizeof(type) * n;                        \
  58                 ceph_decode_need(p, end, need, bad);            \
  59                 *p += need;                                     \
  60         } while (0)
  61
  62 #define __decode_and_drop_map(p, end, ktype, vtype, bad)        \
  63         do {                                                    \
  64                 u32 n;                                          \
  65                 size_t need;                                    \
  66                 ceph_decode_32_safe(p, end, n, bad);            \
  67                 need = (sizeof(ktype) + sizeof(vtype)) * n;     \
  68                 ceph_decode_need(p, end, need, bad);            \
  69                 *p += need;                                     \
  70         } while (0)
  71
  72
  73 static int __decode_and_drop_compat_set(void **p, void* end)
  74 {
  75         int i;
  76         /* compat, ro_compat, incompat*/
  77         for (i = 0; i < 3; i++) {
  78                 u32 n;
  79                 ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
  80                 /* mask */
  81                 *p += sizeof(u64);
  82                 /* names (map<u64, string>) */
  83                 n = ceph_decode_32(p);
  84                 while (n-- > 0) {
  85                         u32 len;
  86                         ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
  87                                          bad);
  88                         *p += sizeof(u64);
  89                         len = ceph_decode_32(p);
  90                         ceph_decode_need(p, end, len, bad);
  91                         *p += len;
  92                 }
  93         }
  94         return 0;
  95 bad:
  96         return -1;
  97 }
  98
  99 /*
 100  * Decode an MDS map
 101  *
 102  * Ignore any fields we don't care about (there are quite a few of
 103  * them).
 104  */
 105 struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 106 {
 107         struct ceph_mdsmap *m;
 108         const void *start = *p;
 109         int i, j, n;
 110         int err = -EINVAL;
 111         u8 mdsmap_v, mdsmap_cv;
 112         u16 mdsmap_ev;
 113
 114         m = kzalloc(sizeof(*m), GFP_NOFS);
 115         if (m == NULL)
 116                 return ERR_PTR(-ENOMEM);
 117
 118         ceph_decode_need(p, end, 1 + 1, bad);
 119         mdsmap_v = ceph_decode_8(p);
 120         mdsmap_cv = ceph_decode_8(p);
 121         if (mdsmap_v >= 4) {
 122                u32 mdsmap_len;
 123                ceph_decode_32_safe(p, end, mdsmap_len, bad);
 124                if (end < *p + mdsmap_len)
 125                        goto bad;
 126                end = *p + mdsmap_len;
 127         }
 128
 129         ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
 130         m->m_epoch = ceph_decode_32(p);
 131         m->m_client_epoch = ceph_decode_32(p);
 132         m->m_last_failure = ceph_decode_32(p);
 133         m->m_root = ceph_decode_32(p);
 134         m->m_session_timeout = ceph_decode_32(p);
 135         m->m_session_autoclose = ceph_decode_32(p);
 136         m->m_max_file_size = ceph_decode_64(p);
 137         m->m_max_mds = ceph_decode_32(p);
 138
 139         m->m_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS);
 140         if (m->m_info == NULL)
 141                 goto nomem;
 142
 143         /* pick out active nodes from mds_info (state > 0) */
 144         n = ceph_decode_32(p);
 145         for (i = 0; i < n; i++) {
 146                 u64 global_id;
 147                 u32 namelen;
 148                 s32 mds, inc, state;
 149                 u64 state_seq;
 150                 u8 info_v;
 151                 void *info_end = NULL;
 152                 struct ceph_entity_addr addr;
 153                 u32 num_export_targets;
 154                 void *pexport_targets = NULL;
 155                 struct ceph_timespec laggy_since;
 156                 struct ceph_mds_info *info;
 157
 158                 ceph_decode_need(p, end, sizeof(u64) + 1, bad);
 159                 global_id = ceph_decode_64(p);
 160                 info_v= ceph_decode_8(p);
 161                 if (info_v >= 4) {
 162                         u32 info_len;
 163                         u8 info_cv;
 164                         ceph_decode_need(p, end, 1 + sizeof(u32), bad);
 165                         info_cv = ceph_decode_8(p);
 166                         info_len = ceph_decode_32(p);
 167                         info_end = *p + info_len;
 168                         if (info_end > end)
 169                                 goto bad;
 170                 }
 171
 172                 ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
 173                 *p += sizeof(u64);
 174                 namelen = ceph_decode_32(p);  /* skip mds name */
 175                 *p += namelen;
 176
 177                 ceph_decode_need(p, end,
 178                                  4*sizeof(u32) + sizeof(u64) +
 179                                  sizeof(addr) + sizeof(struct ceph_timespec),
 180                                  bad);
 181                 mds = ceph_decode_32(p);
 182                 inc = ceph_decode_32(p);
 183                 state = ceph_decode_32(p);
 184                 state_seq = ceph_decode_64(p);
 185                 ceph_decode_copy(p, &addr, sizeof(addr));
 186                 ceph_decode_addr(&addr);
 187                 ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
 188                 *p += sizeof(u32);
 189                 ceph_decode_32_safe(p, end, namelen, bad);
 190                 *p += namelen;
 191                 if (info_v >= 2) {
 192                         ceph_decode_32_safe(p, end, num_export_targets, bad);
 193                         pexport_targets = *p;
 194                         *p += num_export_targets * sizeof(u32);
 195                 } else {
 196                         num_export_targets = 0;
 197                 }
 198
 199                 if (info_end && *p != info_end) {
 200                         if (*p > info_end)
 201                                 goto bad;
 202                         *p = info_end;
 203                 }
 204
 205                 dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
 206                      i+1, n, global_id, mds, inc,
 207                      ceph_pr_addr(&addr.in_addr),
 208                      ceph_mds_state_name(state));
 209
 210                 if (mds < 0 || mds >= m->m_max_mds || state <= 0)
 211                         continue;
 212
 213                 info = &m->m_info[mds];
 214                 info->global_id = global_id;
 215                 info->state = state;
 216                 info->addr = addr;
 217                 info->laggy = (laggy_since.tv_sec != 0 ||
 218                                laggy_since.tv_nsec != 0);
 219                 info->num_export_targets = num_export_targets;
 220                 if (num_export_targets) {
 221                         info->export_targets = kcalloc(num_export_targets,
 222                                                        sizeof(u32), GFP_NOFS);
 223                         if (info->export_targets == NULL)
 224                                 goto nomem;
 225                         for (j = 0; j < num_export_targets; j++)
 226                                 info->export_targets[j] =
 227                                        ceph_decode_32(&pexport_targets);
 228                 } else {
 229                         info->export_targets = NULL;
 230                 }
 231         }
 232
 233         /* pg_pools */
 234         ceph_decode_32_safe(p, end, n, bad);
 235         m->m_num_data_pg_pools = n;
 236         m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
 237         if (!m->m_data_pg_pools)
 238                 goto nomem;
 239         ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
 240         for (i = 0; i < n; i++)
 241                 m->m_data_pg_pools[i] = ceph_decode_64(p);
 242         m->m_cas_pg_pool = ceph_decode_64(p);
 243         m->m_enabled = m->m_epoch > 1;
 244
 245         mdsmap_ev = 1;
 246         if (mdsmap_v >= 2) {
 247                 ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
 248         }
 249         if (mdsmap_ev >= 3) {
 250                 if (__decode_and_drop_compat_set(p, end) < 0)
 251                         goto bad_ext;
 252         }
 253         /* metadata_pool */
 254         if (mdsmap_ev < 5) {
 255                 __decode_and_drop_type(p, end, u32, bad_ext);
 256         } else {
 257                 __decode_and_drop_type(p, end, u64, bad_ext);
 258         }
 259
 260         /* created + modified + tableserver */
 261         __decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
 262         __decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
 263         __decode_and_drop_type(p, end, u32, bad_ext);
 264
 265         /* in */
 266         {
 267                 int num_laggy = 0;
 268                 ceph_decode_32_safe(p, end, n, bad_ext);
 269                 ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
 270
 271                 for (i = 0; i < n; i++) {
 272                         s32 mds = ceph_decode_32(p);
 273                         if (mds >= 0 && mds < m->m_max_mds) {
 274                                 if (m->m_info[mds].laggy)
 275                                         num_laggy++;
 276                         }
 277                 }
 278                 m->m_num_laggy = num_laggy;
 279         }
 280
 281         /* inc */
 282         __decode_and_drop_map(p, end, u32, u32, bad_ext);
 283         /* up */
 284         __decode_and_drop_map(p, end, u32, u64, bad_ext);
 285         /* failed */
 286         __decode_and_drop_set(p, end, u32, bad_ext);
 287         /* stopped */
 288         __decode_and_drop_set(p, end, u32, bad_ext);
 289
 290         if (mdsmap_ev >= 4) {
 291                 /* last_failure_osd_epoch */
 292                 __decode_and_drop_type(p, end, u32, bad_ext);
 293         }
 294         if (mdsmap_ev >= 6) {
 295                 /* ever_allowed_snaps */
 296                 __decode_and_drop_type(p, end, u8, bad_ext);
 297                 /* explicitly_allowed_snaps */
 298                 __decode_and_drop_type(p, end, u8, bad_ext);
 299         }
 300         if (mdsmap_ev >= 7) {
 301                 /* inline_data_enabled */
 302                 __decode_and_drop_type(p, end, u8, bad_ext);
 303         }
 304         if (mdsmap_ev >= 8) {
 305                 u32 name_len;
 306                 /* enabled */
 307                 ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
 308                 ceph_decode_32_safe(p, end, name_len, bad_ext);
 309                 ceph_decode_need(p, end, name_len, bad_ext);
 310                 *p += name_len;
 311         }
 312         /* damaged */
 313         if (mdsmap_ev >= 9) {
 314                 size_t need;
 315                 ceph_decode_32_safe(p, end, n, bad_ext);
 316                 need = sizeof(u32) * n;
 317                 ceph_decode_need(p, end, need, bad_ext);
 318                 *p += need;
 319                 m->m_damaged = n > 0;
 320         } else {
 321                 m->m_damaged = false;
 322         }
 323 bad_ext:
 324         *p = end;
 325         dout("mdsmap_decode success epoch %u\n", m->m_epoch);
 326         return m;
 327 nomem:
 328         err = -ENOMEM;
 329         goto out_err;
 330 bad:
 331         pr_err("corrupt mdsmap\n");
 332         print_hex_dump(KERN_DEBUG, "mdsmap: ",
 333                        DUMP_PREFIX_OFFSET, 16, 1,
 334                        start, end - start, true);
 335 out_err:
 336         ceph_mdsmap_destroy(m);
 337         return ERR_PTR(err);
 338 }
 339
 340 void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
 341 {
 342         int i;
 343
 344         for (i = 0; i < m->m_max_mds; i++)
 345                 kfree(m->m_info[i].export_targets);
 346         kfree(m->m_info);
 347         kfree(m->m_data_pg_pools);
 348         kfree(m);
 349 }
 350
 351 bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
 352 {
 353         int i, nr_active = 0;
 354         if (!m->m_enabled)
 355                 return false;
 356         if (m->m_damaged)
 357                 return false;
 358         if (m->m_num_laggy > 0)
 359                 return false;
 360         for (i = 0; i < m->m_max_mds; i++) {
 361                 if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
 362                         nr_active++;
 363         }
 364         return nr_active > 0;
 365 }