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
  17 /*
  18  * choose a random mds that is "up" (i.e. has a state > 0), or -1.
  19  */
  20 int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
  21 {
  22         int n = 0;
  23         int i;
  24
  25         /* special case for one mds */
  26         if (1 == m->m_num_mds && m->m_info[0].state > 0)
  27                 return 0;
  28
  29         /* count */
  30         for (i = 0; i < m->m_num_mds; i++)
  31                 if (m->m_info[i].state > 0)
  32                         n++;
  33         if (n == 0)
  34                 return -1;
  35
  36         /* pick */
  37         n = prandom_u32() % n;
  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;
 111         u8 mdsmap_v, mdsmap_cv;
 112         u16 mdsmap_ev;
 113
 114         m = kzalloc(sizeof(*m), GFP_NOFS);
 115         if (!m)
 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         m->m_num_mds = m->m_max_mds;
 139
 140         m->m_info = kcalloc(m->m_num_mds, sizeof(*m->m_info), GFP_NOFS);
 141         if (!m->m_info)
 142                 goto nomem;
 143
 144         /* pick out active nodes from mds_info (state > 0) */
 145         n = ceph_decode_32(p);
 146         for (i = 0; i < n; i++) {
 147                 u64 global_id;
 148                 u32 namelen;
 149                 s32 mds, inc, state;
 150                 u64 state_seq;
 151                 u8 info_v;
 152                 void *info_end = NULL;
 153                 struct ceph_entity_addr addr;
 154                 u32 num_export_targets;
 155                 void *pexport_targets = NULL;
 156                 struct ceph_timespec laggy_since;
 157                 struct ceph_mds_info *info;
 158
 159                 ceph_decode_need(p, end, sizeof(u64) + 1, bad);
 160                 global_id = ceph_decode_64(p);
 161                 info_v= ceph_decode_8(p);
 162                 if (info_v >= 4) {
 163                         u32 info_len;
 164                         u8 info_cv;
 165                         ceph_decode_need(p, end, 1 + sizeof(u32), bad);
 166                         info_cv = ceph_decode_8(p);
 167                         info_len = ceph_decode_32(p);
 168                         info_end = *p + info_len;
 169                         if (info_end > end)
 170                                 goto bad;
 171                 }
 172
 173                 ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
 174                 *p += sizeof(u64);
 175                 namelen = ceph_decode_32(p);  /* skip mds name */
 176                 *p += namelen;
 177
 178                 ceph_decode_need(p, end,
 179                                  4*sizeof(u32) + sizeof(u64) +
 180                                  sizeof(addr) + sizeof(struct ceph_timespec),
 181                                  bad);
 182                 mds = ceph_decode_32(p);
 183                 inc = ceph_decode_32(p);
 184                 state = ceph_decode_32(p);
 185                 state_seq = ceph_decode_64(p);
 186                 err = ceph_decode_entity_addr(p, end, &addr);
 187                 if (err)
 188                         goto corrupt;
 189                 ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
 190                 *p += sizeof(u32);
 191                 ceph_decode_32_safe(p, end, namelen, bad);
 192                 *p += namelen;
 193                 if (info_v >= 2) {
 194                         ceph_decode_32_safe(p, end, num_export_targets, bad);
 195                         pexport_targets = *p;
 196                         *p += num_export_targets * sizeof(u32);
 197                 } else {
 198                         num_export_targets = 0;
 199                 }
 200
 201                 if (info_end && *p != info_end) {
 202                         if (*p > info_end)
 203                                 goto bad;
 204                         *p = info_end;
 205                 }
 206
 207                 dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
 208                      i+1, n, global_id, mds, inc,
 209                      ceph_pr_addr(&addr),
 210                      ceph_mds_state_name(state));
 211
 212                 if (mds < 0 || state <= 0)
 213                         continue;
 214
 215                 if (mds >= m->m_num_mds) {
 216                         int new_num = max(mds + 1, m->m_num_mds * 2);
 217                         void *new_m_info = krealloc(m->m_info,
 218                                                 new_num * sizeof(*m->m_info),
 219                                                 GFP_NOFS | __GFP_ZERO);
 220                         if (!new_m_info)
 221                                 goto nomem;
 222                         m->m_info = new_m_info;
 223                         m->m_num_mds = new_num;
 224                 }
 225
 226                 info = &m->m_info[mds];
 227                 info->global_id = global_id;
 228                 info->state = state;
 229                 info->addr = addr;
 230                 info->laggy = (laggy_since.tv_sec != 0 ||
 231                                laggy_since.tv_nsec != 0);
 232                 info->num_export_targets = num_export_targets;
 233                 if (num_export_targets) {
 234                         info->export_targets = kcalloc(num_export_targets,
 235                                                        sizeof(u32), GFP_NOFS);
 236                         if (!info->export_targets)
 237                                 goto nomem;
 238                         for (j = 0; j < num_export_targets; j++)
 239                                 info->export_targets[j] =
 240                                        ceph_decode_32(&pexport_targets);
 241                 } else {
 242                         info->export_targets = NULL;
 243                 }
 244         }
 245         if (m->m_num_mds > m->m_max_mds) {
 246                 /* find max up mds */
 247                 for (i = m->m_num_mds; i >= m->m_max_mds; i--) {
 248                         if (i == 0 || m->m_info[i-1].state > 0)
 249                                 break;
 250                 }
 251                 m->m_num_mds = i;
 252         }
 253
 254         /* pg_pools */
 255         ceph_decode_32_safe(p, end, n, bad);
 256         m->m_num_data_pg_pools = n;
 257         m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
 258         if (!m->m_data_pg_pools)
 259                 goto nomem;
 260         ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
 261         for (i = 0; i < n; i++)
 262                 m->m_data_pg_pools[i] = ceph_decode_64(p);
 263         m->m_cas_pg_pool = ceph_decode_64(p);
 264         m->m_enabled = m->m_epoch > 1;
 265
 266         mdsmap_ev = 1;
 267         if (mdsmap_v >= 2) {
 268                 ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
 269         }
 270         if (mdsmap_ev >= 3) {
 271                 if (__decode_and_drop_compat_set(p, end) < 0)
 272                         goto bad_ext;
 273         }
 274         /* metadata_pool */
 275         if (mdsmap_ev < 5) {
 276                 __decode_and_drop_type(p, end, u32, bad_ext);
 277         } else {
 278                 __decode_and_drop_type(p, end, u64, bad_ext);
 279         }
 280
 281         /* created + modified + tableserver */
 282         __decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
 283         __decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
 284         __decode_and_drop_type(p, end, u32, bad_ext);
 285
 286         /* in */
 287         {
 288                 int num_laggy = 0;
 289                 ceph_decode_32_safe(p, end, n, bad_ext);
 290                 ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
 291
 292                 for (i = 0; i < n; i++) {
 293                         s32 mds = ceph_decode_32(p);
 294                         if (mds >= 0 && mds < m->m_num_mds) {
 295                                 if (m->m_info[mds].laggy)
 296                                         num_laggy++;
 297                         }
 298                 }
 299                 m->m_num_laggy = num_laggy;
 300
 301                 if (n > m->m_num_mds) {
 302                         void *new_m_info = krealloc(m->m_info,
 303                                                     n * sizeof(*m->m_info),
 304                                                     GFP_NOFS | __GFP_ZERO);
 305                         if (!new_m_info)
 306                                 goto nomem;
 307                         m->m_info = new_m_info;
 308                 }
 309                 m->m_num_mds = n;
 310         }
 311
 312         /* inc */
 313         __decode_and_drop_map(p, end, u32, u32, bad_ext);
 314         /* up */
 315         __decode_and_drop_map(p, end, u32, u64, bad_ext);
 316         /* failed */
 317         __decode_and_drop_set(p, end, u32, bad_ext);
 318         /* stopped */
 319         __decode_and_drop_set(p, end, u32, bad_ext);
 320
 321         if (mdsmap_ev >= 4) {
 322                 /* last_failure_osd_epoch */
 323                 __decode_and_drop_type(p, end, u32, bad_ext);
 324         }
 325         if (mdsmap_ev >= 6) {
 326                 /* ever_allowed_snaps */
 327                 __decode_and_drop_type(p, end, u8, bad_ext);
 328                 /* explicitly_allowed_snaps */
 329                 __decode_and_drop_type(p, end, u8, bad_ext);
 330         }
 331         if (mdsmap_ev >= 7) {
 332                 /* inline_data_enabled */
 333                 __decode_and_drop_type(p, end, u8, bad_ext);
 334         }
 335         if (mdsmap_ev >= 8) {
 336                 u32 name_len;
 337                 /* enabled */
 338                 ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
 339                 ceph_decode_32_safe(p, end, name_len, bad_ext);
 340                 ceph_decode_need(p, end, name_len, bad_ext);
 341                 *p += name_len;
 342         }
 343         /* damaged */
 344         if (mdsmap_ev >= 9) {
 345                 size_t need;
 346                 ceph_decode_32_safe(p, end, n, bad_ext);
 347                 need = sizeof(u32) * n;
 348                 ceph_decode_need(p, end, need, bad_ext);
 349                 *p += need;
 350                 m->m_damaged = n > 0;
 351         } else {
 352                 m->m_damaged = false;
 353         }
 354 bad_ext:
 355         *p = end;
 356         dout("mdsmap_decode success epoch %u\n", m->m_epoch);
 357         return m;
 358 nomem:
 359         err = -ENOMEM;
 360         goto out_err;
 361 corrupt:
 362         pr_err("corrupt mdsmap\n");
 363         print_hex_dump(KERN_DEBUG, "mdsmap: ",
 364                        DUMP_PREFIX_OFFSET, 16, 1,
 365                        start, end - start, true);
 366 out_err:
 367         ceph_mdsmap_destroy(m);
 368         return ERR_PTR(err);
 369 bad:
 370         err = -EINVAL;
 371         goto corrupt;
 372 }
 373
 374 void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
 375 {
 376         int i;
 377
 378         for (i = 0; i < m->m_num_mds; i++)
 379                 kfree(m->m_info[i].export_targets);
 380         kfree(m->m_info);
 381         kfree(m->m_data_pg_pools);
 382         kfree(m);
 383 }
 384
 385 bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
 386 {
 387         int i, nr_active = 0;
 388         if (!m->m_enabled)
 389                 return false;
 390         if (m->m_damaged)
 391                 return false;
 392         if (m->m_num_laggy > 0)
 393                 return false;
 394         for (i = 0; i < m->m_num_mds; i++) {
 395                 if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
 396                         nr_active++;
 397         }
 398         return nr_active > 0;
 399 }