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         i = 0;
  39         for (i = 0; n > 0; i++, n--)
  40                 while (m->m_info[i].state <= 0)
  41                         i++;
  42
  43         return i;
  44 }
  45
  46 #define __decode_and_drop_type(p, end, type, bad)               \
  47         do {                                                    \
  48                 if (*p + sizeof(type) > end)                    \
  49                         goto bad;                               \
  50                 *p += sizeof(type);                             \
  51         } while (0)
  52
  53 #define __decode_and_drop_set(p, end, type, bad)                \
  54         do {                                                    \
  55                 u32 n;                                          \
  56                 size_t need;                                    \
  57                 ceph_decode_32_safe(p, end, n, bad);            \
  58                 need = sizeof(type) * n;                        \
  59                 ceph_decode_need(p, end, need, bad);            \
  60                 *p += need;                                     \
  61         } while (0)
  62
  63 #define __decode_and_drop_map(p, end, ktype, vtype, bad)        \
  64         do {                                                    \
  65                 u32 n;                                          \
  66                 size_t need;                                    \
  67                 ceph_decode_32_safe(p, end, n, bad);            \
  68                 need = (sizeof(ktype) + sizeof(vtype)) * n;     \
  69                 ceph_decode_need(p, end, need, bad);            \
  70                 *p += need;                                     \
  71         } while (0)
  72
  73
  74 static int __decode_and_drop_compat_set(void **p, void* end)
  75 {
  76         int i;
  77         /* compat, ro_compat, incompat*/
  78         for (i = 0; i < 3; i++) {
  79                 u32 n;
  80                 ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
  81                 /* mask */
  82                 *p += sizeof(u64);
  83                 /* names (map<u64, string>) */
  84                 n = ceph_decode_32(p);
  85                 while (n-- > 0) {
  86                         u32 len;
  87                         ceph_decode_need(p, end, sizeof(u64) + sizeof(u32),
  88                                          bad);
  89                         *p += sizeof(u64);
  90                         len = ceph_decode_32(p);
  91                         ceph_decode_need(p, end, len, bad);
  92                         *p += len;
  93                 }
  94         }
  95         return 0;
  96 bad:
  97         return -1;
  98 }
  99
 100 /*
 101  * Decode an MDS map
 102  *
 103  * Ignore any fields we don't care about (there are quite a few of
 104  * them).
 105  */
 106 struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 107 {
 108         struct ceph_mdsmap *m;
 109         const void *start = *p;
 110         int i, j, n;
 111         int err = -EINVAL;
 112         u8 mdsmap_v, mdsmap_cv;
 113         u16 mdsmap_ev;
 114
 115         m = kzalloc(sizeof(*m), GFP_NOFS);
 116         if (!m)
 117                 return ERR_PTR(-ENOMEM);
 118
 119         ceph_decode_need(p, end, 1 + 1, bad);
 120         mdsmap_v = ceph_decode_8(p);
 121         mdsmap_cv = ceph_decode_8(p);
 122         if (mdsmap_v >= 4) {
 123                u32 mdsmap_len;
 124                ceph_decode_32_safe(p, end, mdsmap_len, bad);
 125                if (end < *p + mdsmap_len)
 126                        goto bad;
 127                end = *p + mdsmap_len;
 128         }
 129
 130         ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
 131         m->m_epoch = ceph_decode_32(p);
 132         m->m_client_epoch = ceph_decode_32(p);
 133         m->m_last_failure = ceph_decode_32(p);
 134         m->m_root = ceph_decode_32(p);
 135         m->m_session_timeout = ceph_decode_32(p);
 136         m->m_session_autoclose = ceph_decode_32(p);
 137         m->m_max_file_size = ceph_decode_64(p);
 138         m->m_max_mds = ceph_decode_32(p);
 139         m->m_num_mds = m->m_max_mds;
 140
 141         m->m_info = kcalloc(m->m_num_mds, sizeof(*m->m_info), GFP_NOFS);
 142         if (!m->m_info)
 143                 goto nomem;
 144
 145         /* pick out active nodes from mds_info (state > 0) */
 146         n = ceph_decode_32(p);
 147         for (i = 0; i < n; i++) {
 148                 u64 global_id;
 149                 u32 namelen;
 150                 s32 mds, inc, state;
 151                 u64 state_seq;
 152                 u8 info_v;
 153                 void *info_end = NULL;
 154                 struct ceph_entity_addr addr;
 155                 u32 num_export_targets;
 156                 void *pexport_targets = NULL;
 157                 struct ceph_timespec laggy_since;
 158                 struct ceph_mds_info *info;
 159
 160                 ceph_decode_need(p, end, sizeof(u64) + 1, bad);
 161                 global_id = ceph_decode_64(p);
 162                 info_v= ceph_decode_8(p);
 163                 if (info_v >= 4) {
 164                         u32 info_len;
 165                         u8 info_cv;
 166                         ceph_decode_need(p, end, 1 + sizeof(u32), bad);
 167                         info_cv = ceph_decode_8(p);
 168                         info_len = ceph_decode_32(p);
 169                         info_end = *p + info_len;
 170                         if (info_end > end)
 171                                 goto bad;
 172                 }
 173
 174                 ceph_decode_need(p, end, sizeof(u64) + sizeof(u32), bad);
 175                 *p += sizeof(u64);
 176                 namelen = ceph_decode_32(p);  /* skip mds name */
 177                 *p += namelen;
 178
 179                 ceph_decode_need(p, end,
 180                                  4*sizeof(u32) + sizeof(u64) +
 181                                  sizeof(addr) + sizeof(struct ceph_timespec),
 182                                  bad);
 183                 mds = ceph_decode_32(p);
 184                 inc = ceph_decode_32(p);
 185                 state = ceph_decode_32(p);
 186                 state_seq = ceph_decode_64(p);
 187                 ceph_decode_copy(p, &addr, sizeof(addr));
 188                 ceph_decode_addr(&addr);
 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.in_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 bad:
 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 }
 370
 371 void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
 372 {
 373         int i;
 374
 375         for (i = 0; i < m->m_num_mds; i++)
 376                 kfree(m->m_info[i].export_targets);
 377         kfree(m->m_info);
 378         kfree(m->m_data_pg_pools);
 379         kfree(m);
 380 }
 381
 382 bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
 383 {
 384         int i, nr_active = 0;
 385         if (!m->m_enabled)
 386                 return false;
 387         if (m->m_damaged)
 388                 return false;
 389         if (m->m_num_laggy > 0)
 390                 return false;
 391         for (i = 0; i < m->m_num_mds; i++) {
 392                 if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
 393                         nr_active++;
 394         }
 395         return nr_active > 0;
 396 }