fs/ceph/mdsmap.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/ceph/ceph_debug.h>
   3
   4 #include <linux/bug.h>
   5 #include <linux/err.h>
   6 #include <linux/random.h>
   7 #include <linux/slab.h>
   8 #include <linux/types.h>
   9
  10 #include <linux/ceph/mdsmap.h>
  11 #include <linux/ceph/messenger.h>
  12 #include <linux/ceph/decode.h>
  13
  14 #include "super.h"
  15
  16 #define CEPH_MDS_IS_READY(i, ignore_laggy) \
  17         (m->m_info[i].state > 0 && ignore_laggy ? true : !m->m_info[i].laggy)
  18
  19 static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
  20 {
  21         int n = 0;
  22         int i, j;
  23
  24         /* count */
  25         for (i = 0; i < m->possible_max_rank; i++)
  26                 if (CEPH_MDS_IS_READY(i, ignore_laggy))
  27                         n++;
  28         if (n == 0)
  29                 return -1;
  30
  31         /* pick */
  32         n = prandom_u32() % n;
  33         for (j = 0, i = 0; i < m->possible_max_rank; i++) {
  34                 if (CEPH_MDS_IS_READY(i, ignore_laggy))
  35                         j++;
  36                 if (j > n)
  37                         break;
  38         }
  39
  40         return i;
  41 }
  42
  43 /*
  44  * choose a random mds that is "up" (i.e. has a state > 0), or -1.
  45  */
  46 int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
  47 {
  48         int mds;
  49
  50         mds = __mdsmap_get_random_mds(m, false);
  51         if (mds == m->possible_max_rank || mds == -1)
  52                 mds = __mdsmap_get_random_mds(m, true);
  53
  54         return mds == m->possible_max_rank ? -1 : mds;
  55 }
  56
  57 #define __decode_and_drop_type(p, end, type, bad)               \
  58         do {                                                    \
  59                 if (*p + sizeof(type) > end)                    \
  60                         goto bad;                               \
  61                 *p += sizeof(type);                             \
  62         } while (0)
  63
  64 #define __decode_and_drop_set(p, end, type, bad)                \
  65         do {                                                    \
  66                 u32 n;                                          \
  67                 size_t need;                                    \
  68                 ceph_decode_32_safe(p, end, n, bad);            \
  69                 need = sizeof(type) * n;                        \
  70                 ceph_decode_need(p, end, need, bad);            \
  71                 *p += need;                                     \
  72         } while (0)
  73
  74 #define __decode_and_drop_map(p, end, ktype, vtype, bad)        \
  75         do {                                                    \
  76                 u32 n;                                          \
  77                 size_t need;                                    \
  78                 ceph_decode_32_safe(p, end, n, bad);            \
  79                 need = (sizeof(ktype) + sizeof(vtype)) * n;     \
  80                 ceph_decode_need(p, end, need, bad);            \
  81                 *p += need;                                     \
  82         } while (0)
  83
  84
  85 static int __decode_and_drop_compat_set(void **p, void* end)
  86 {
  87         int i;
  88         /* compat, ro_compat, incompat*/
  89         for (i = 0; i < 3; i++) {
  90                 u32 n;
  91                 ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
  92                 /* mask */
  93                 *p += sizeof(u64);
  94                 /* names (map<u64, string>) */
  95                 n = ceph_decode_32(p);
  96                 while (n-- > 0) {
  97                         u32 len;
  98                         ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
  99                                          bad);
 100                         *p += sizeof(u64);
 101                         len = ceph_decode_32(p);
 102                         ceph_decode_need(p, end, len, bad);
 103                         *p += len;
 104                 }
 105         }
 106         return 0;
 107 bad:
 108         return -1;
 109 }
 110
 111 /*
 112  * Decode an MDS map
 113  *
 114  * Ignore any fields we don't care about (there are quite a few of
 115  * them).
 116  */
 117 struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 118 {
 119         struct ceph_mdsmap *m;
 120         const void *start = *p;
 121         int i, j, n;
 122         int err;
 123         u8 mdsmap_v, mdsmap_cv;
 124         u16 mdsmap_ev;
 125
 126         m = kzalloc(sizeof(*m), GFP_NOFS);
 127         if (!m)
 128                 return ERR_PTR(-ENOMEM);
 129
 130         ceph_decode_need(p, end, 1 + 1, bad);
 131         mdsmap_v = ceph_decode_8(p);
 132         mdsmap_cv = ceph_decode_8(p);
 133         if (mdsmap_v >= 4) {
 134                u32 mdsmap_len;
 135                ceph_decode_32_safe(p, end, mdsmap_len, bad);
 136                if (end < *p + mdsmap_len)
 137                        goto bad;
 138                end = *p + mdsmap_len;
 139         }
 140
 141         ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
 142         m->m_epoch = ceph_decode_32(p);
 143         m->m_client_epoch = ceph_decode_32(p);
 144         m->m_last_failure = ceph_decode_32(p);
 145         m->m_root = ceph_decode_32(p);
 146         m->m_session_timeout = ceph_decode_32(p);
 147         m->m_session_autoclose = ceph_decode_32(p);
 148         m->m_max_file_size = ceph_decode_64(p);
 149         m->m_max_mds = ceph_decode_32(p);
 150
 151         /*
 152          * pick out the active nodes as the m_num_active_mds, the
 153          * m_num_active_mds maybe larger than m_max_mds when decreasing
 154          * the max_mds in cluster side, in other case it should less
 155          * than or equal to m_max_mds.
 156          */
 157         m->m_num_active_mds = n = ceph_decode_32(p);
 158
 159         /*
 160          * the possible max rank, it maybe larger than the m_num_active_mds,
 161          * for example if the mds_max == 2 in the cluster, when the MDS(0)
 162          * was laggy and being replaced by a new MDS, we will temporarily
 163          * receive a new mds map with n_num_mds == 1 and the active MDS(1),
 164          * and the mds rank >= m_num_active_mds.
 165          */
 166         m->possible_max_rank = max(m->m_num_active_mds, m->m_max_mds);
 167
 168         m->m_info = kcalloc(m->possible_max_rank, sizeof(*m->m_info), GFP_NOFS);
 169         if (!m->m_info)
 170                 goto nomem;
 171
 172         /* pick out active nodes from mds_info (state > 0) */
 173         for (i = 0; i < n; i++) {
 174                 u64 global_id;
 175                 u32 namelen;
 176                 s32 mds, inc, state;
 177                 u64 state_seq;
 178                 u8 info_v;
 179                 void *info_end = NULL;
 180                 struct ceph_entity_addr addr;
 181                 u32 num_export_targets;
 182                 void *pexport_targets = NULL;
 183                 struct ceph_timespec laggy_since;
 184                 struct ceph_mds_info *info;
 185                 bool laggy;
 186
 187                 ceph_decode_need(p, end, sizeof(u64) + 1, bad);
 188                 global_id = ceph_decode_64(p);
 189                 info_v= ceph_decode_8(p);
 190                 if (info_v >= 4) {
 191                         u32 info_len;
 192                         u8 info_cv;
 193                         ceph_decode_need(p, end, 1 + sizeof(u32), bad);
 194                         info_cv = ceph_decode_8(p);
 195                         info_len = ceph_decode_32(p);
 196                         info_end = *p + info_len;
 197                         if (info_end > end)
 198                                 goto bad;
 199                 }
 200
 201                 ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
 202                 *p += sizeof(u64);
 203                 namelen = ceph_decode_32(p);  /* skip mds name */
 204                 *p += namelen;
 205
 206                 ceph_decode_need(p, end,
 207                                  4*sizeof(u32) + sizeof(u64) +
 208                                  sizeof(addr) + sizeof(struct ceph_timespec),
 209                                  bad);
 210                 mds = ceph_decode_32(p);
 211                 inc = ceph_decode_32(p);
 212                 state = ceph_decode_32(p);
 213                 state_seq = ceph_decode_64(p);
 214                 err = ceph_decode_entity_addr(p, end, &addr);
 215                 if (err)
 216                         goto corrupt;
 217                 ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
 218                 laggy = laggy_since.tv_sec != 0 || laggy_since.tv_nsec != 0;
 219                 *p += sizeof(u32);
 220                 ceph_decode_32_safe(p, end, namelen, bad);
 221                 *p += namelen;
 222                 if (info_v >= 2) {
 223                         ceph_decode_32_safe(p, end, num_export_targets, bad);
 224                         pexport_targets = *p;
 225                         *p += num_export_targets * sizeof(u32);
 226                 } else {
 227                         num_export_targets = 0;
 228                 }
 229
 230                 if (info_end && *p != info_end) {
 231                         if (*p > info_end)
 232                                 goto bad;
 233                         *p = info_end;
 234                 }
 235
 236                 dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s%s\n",
 237                      i+1, n, global_id, mds, inc,
 238                      ceph_pr_addr(&addr),
 239                      ceph_mds_state_name(state),
 240                      laggy ? "(laggy)" : "");
 241
 242                 if (mds < 0 || mds >= m->possible_max_rank) {
 243                         pr_warn("mdsmap_decode got incorrect mds(%d)\n", mds);
 244                         continue;
 245                 }
 246
 247                 if (state <= 0) {
 248                         pr_warn("mdsmap_decode got incorrect state(%s)\n",
 249                                 ceph_mds_state_name(state));
 250                         continue;
 251                 }
 252
 253                 info = &m->m_info[mds];
 254                 info->global_id = global_id;
 255                 info->state = state;
 256                 info->addr = addr;
 257                 info->laggy = laggy;
 258                 info->num_export_targets = num_export_targets;
 259                 if (num_export_targets) {
 260                         info->export_targets = kcalloc(num_export_targets,
 261                                                        sizeof(u32), GFP_NOFS);
 262                         if (!info->export_targets)
 263                                 goto nomem;
 264                         for (j = 0; j < num_export_targets; j++)
 265                                 info->export_targets[j] =
 266                                        ceph_decode_32(&pexport_targets);
 267                 } else {
 268                         info->export_targets = NULL;
 269                 }
 270         }
 271
 272         /* pg_pools */
 273         ceph_decode_32_safe(p, end, n, bad);
 274         m->m_num_data_pg_pools = n;
 275         m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
 276         if (!m->m_data_pg_pools)
 277                 goto nomem;
 278         ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
 279         for (i = 0; i < n; i++)
 280                 m->m_data_pg_pools[i] = ceph_decode_64(p);
 281         m->m_cas_pg_pool = ceph_decode_64(p);
 282         m->m_enabled = m->m_epoch > 1;
 283
 284         mdsmap_ev = 1;
 285         if (mdsmap_v >= 2) {
 286                 ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
 287         }
 288         if (mdsmap_ev >= 3) {
 289                 if (__decode_and_drop_compat_set(p, end) < 0)
 290                         goto bad_ext;
 291         }
 292         /* metadata_pool */
 293         if (mdsmap_ev < 5) {
 294                 __decode_and_drop_type(p, end, u32, bad_ext);
 295         } else {
 296                 __decode_and_drop_type(p, end, u64, bad_ext);
 297         }
 298
 299         /* created + modified + tableserver */
 300         __decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
 301         __decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
 302         __decode_and_drop_type(p, end, u32, bad_ext);
 303
 304         /* in */
 305         {
 306                 int num_laggy = 0;
 307                 ceph_decode_32_safe(p, end, n, bad_ext);
 308                 ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
 309
 310                 for (i = 0; i < n; i++) {
 311                         s32 mds = ceph_decode_32(p);
 312                         if (mds >= 0 && mds < m->possible_max_rank) {
 313                                 if (m->m_info[mds].laggy)
 314                                         num_laggy++;
 315                         }
 316                 }
 317                 m->m_num_laggy = num_laggy;
 318
 319                 if (n > m->possible_max_rank) {
 320                         void *new_m_info = krealloc(m->m_info,
 321                                                     n * sizeof(*m->m_info),
 322                                                     GFP_NOFS | __GFP_ZERO);
 323                         if (!new_m_info)
 324                                 goto nomem;
 325                         m->m_info = new_m_info;
 326                 }
 327                 m->possible_max_rank = n;
 328         }
 329
 330         /* inc */
 331         __decode_and_drop_map(p, end, u32, u32, bad_ext);
 332         /* up */
 333         __decode_and_drop_map(p, end, u32, u64, bad_ext);
 334         /* failed */
 335         __decode_and_drop_set(p, end, u32, bad_ext);
 336         /* stopped */
 337         __decode_and_drop_set(p, end, u32, bad_ext);
 338
 339         if (mdsmap_ev >= 4) {
 340                 /* last_failure_osd_epoch */
 341                 __decode_and_drop_type(p, end, u32, bad_ext);
 342         }
 343         if (mdsmap_ev >= 6) {
 344                 /* ever_allowed_snaps */
 345                 __decode_and_drop_type(p, end, u8, bad_ext);
 346                 /* explicitly_allowed_snaps */
 347                 __decode_and_drop_type(p, end, u8, bad_ext);
 348         }
 349         if (mdsmap_ev >= 7) {
 350                 /* inline_data_enabled */
 351                 __decode_and_drop_type(p, end, u8, bad_ext);
 352         }
 353         if (mdsmap_ev >= 8) {
 354                 u32 name_len;
 355                 /* enabled */
 356                 ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
 357                 ceph_decode_32_safe(p, end, name_len, bad_ext);
 358                 ceph_decode_need(p, end, name_len, bad_ext);
 359                 *p += name_len;
 360         }
 361         /* damaged */
 362         if (mdsmap_ev >= 9) {
 363                 size_t need;
 364                 ceph_decode_32_safe(p, end, n, bad_ext);
 365                 need = sizeof(u32) * n;
 366                 ceph_decode_need(p, end, need, bad_ext);
 367                 *p += need;
 368                 m->m_damaged = n > 0;
 369         } else {
 370                 m->m_damaged = false;
 371         }
 372 bad_ext:
 373         dout("mdsmap_decode m_enabled: %d, m_damaged: %d, m_num_laggy: %d\n",
 374              !!m->m_enabled, !!m->m_damaged, m->m_num_laggy);
 375         *p = end;
 376         dout("mdsmap_decode success epoch %u\n", m->m_epoch);
 377         return m;
 378 nomem:
 379         err = -ENOMEM;
 380         goto out_err;
 381 corrupt:
 382         pr_err("corrupt mdsmap\n");
 383         print_hex_dump(KERN_DEBUG, "mdsmap: ",
 384                        DUMP_PREFIX_OFFSET, 16, 1,
 385                        start, end - start, true);
 386 out_err:
 387         ceph_mdsmap_destroy(m);
 388         return ERR_PTR(err);
 389 bad:
 390         err = -EINVAL;
 391         goto corrupt;
 392 }
 393
 394 void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
 395 {
 396         int i;
 397
 398         for (i = 0; i < m->possible_max_rank; i++)
 399                 kfree(m->m_info[i].export_targets);
 400         kfree(m->m_info);
 401         kfree(m->m_data_pg_pools);
 402         kfree(m);
 403 }
 404
 405 bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
 406 {
 407         int i, nr_active = 0;
 408         if (!m->m_enabled)
 409                 return false;
 410         if (m->m_damaged)
 411                 return false;
 412         if (m->m_num_laggy == m->m_num_active_mds)
 413                 return false;
 414         for (i = 0; i < m->possible_max_rank; i++) {
 415                 if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
 416                         nr_active++;
 417         }
 418         return nr_active > 0;
 419 }