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