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_num_mds && m->m_info[0].state > 0)
  26                 return 0;
  27
  28         /* count */
  29         for (i = 0; i < m->m_num_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)
 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                 ceph_decode_copy(p, &addr, sizeof(addr));
 187                 ceph_decode_addr(&addr);
 188                 ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
 189                 *p += sizeof(u32);
 190                 ceph_decode_32_safe(p, end, namelen, bad);
 191                 *p += namelen;
 192                 if (info_v >= 2) {
 193                         ceph_decode_32_safe(p, end, num_export_targets, bad);
 194                         pexport_targets = *p;
 195                         *p += num_export_targets * sizeof(u32);
 196                 } else {
 197                         num_export_targets = 0;
 198                 }
 199
 200                 if (info_end && *p != info_end) {
 201                         if (*p > info_end)
 202                                 goto bad;
 203                         *p = info_end;
 204                 }
 205
 206                 dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
 207                      i+1, n, global_id, mds, inc,
 208                      ceph_pr_addr(&addr.in_addr),
 209                      ceph_mds_state_name(state));
 210
 211                 if (mds < 0 || state <= 0)
 212                         continue;
 213
 214                 if (mds >= m->m_num_mds) {
 215                         int new_num = max(mds + 1, m->m_num_mds * 2);
 216                         void *new_m_info = krealloc(m->m_info,
 217                                                 new_num * sizeof(*m->m_info),
 218                                                 GFP_NOFS | __GFP_ZERO);
 219                         if (!new_m_info)
 220                                 goto nomem;
 221                         m->m_info = new_m_info;
 222                         m->m_num_mds = new_num;
 223                 }
 224
 225                 info = &m->m_info[mds];
 226                 info->global_id = global_id;
 227                 info->state = state;
 228                 info->addr = addr;
 229                 info->laggy = (laggy_since.tv_sec != 0 ||
 230                                laggy_since.tv_nsec != 0);
 231                 info->num_export_targets = num_export_targets;
 232                 if (num_export_targets) {
 233                         info->export_targets = kcalloc(num_export_targets,
 234                                                        sizeof(u32), GFP_NOFS);
 235                         if (!info->export_targets)
 236                                 goto nomem;
 237                         for (j = 0; j < num_export_targets; j++)
 238                                 info->export_targets[j] =
 239                                        ceph_decode_32(&pexport_targets);
 240                 } else {
 241                         info->export_targets = NULL;
 242                 }
 243         }
 244         if (m->m_num_mds > m->m_max_mds) {
 245                 /* find max up mds */
 246                 for (i = m->m_num_mds; i >= m->m_max_mds; i--) {
 247                         if (i == 0 || m->m_info[i-1].state > 0)
 248                                 break;
 249                 }
 250                 m->m_num_mds = i;
 251         }
 252
 253         /* pg_pools */
 254         ceph_decode_32_safe(p, end, n, bad);
 255         m->m_num_data_pg_pools = n;
 256         m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
 257         if (!m->m_data_pg_pools)
 258                 goto nomem;
 259         ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
 260         for (i = 0; i < n; i++)
 261                 m->m_data_pg_pools[i] = ceph_decode_64(p);
 262         m->m_cas_pg_pool = ceph_decode_64(p);
 263         m->m_enabled = m->m_epoch > 1;
 264
 265         mdsmap_ev = 1;
 266         if (mdsmap_v >= 2) {
 267                 ceph_decode_16_safe(p, end, mdsmap_ev, bad_ext);
 268         }
 269         if (mdsmap_ev >= 3) {
 270                 if (__decode_and_drop_compat_set(p, end) < 0)
 271                         goto bad_ext;
 272         }
 273         /* metadata_pool */
 274         if (mdsmap_ev < 5) {
 275                 __decode_and_drop_type(p, end, u32, bad_ext);
 276         } else {
 277                 __decode_and_drop_type(p, end, u64, bad_ext);
 278         }
 279
 280         /* created + modified + tableserver */
 281         __decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
 282         __decode_and_drop_type(p, end, struct ceph_timespec, bad_ext);
 283         __decode_and_drop_type(p, end, u32, bad_ext);
 284
 285         /* in */
 286         {
 287                 int num_laggy = 0;
 288                 ceph_decode_32_safe(p, end, n, bad_ext);
 289                 ceph_decode_need(p, end, sizeof(u32) * n, bad_ext);
 290
 291                 for (i = 0; i < n; i++) {
 292                         s32 mds = ceph_decode_32(p);
 293                         if (mds >= 0 && mds < m->m_num_mds) {
 294                                 if (m->m_info[mds].laggy)
 295                                         num_laggy++;
 296                         }
 297                 }
 298                 m->m_num_laggy = num_laggy;
 299
 300                 if (n > m->m_num_mds) {
 301                         void *new_m_info = krealloc(m->m_info,
 302                                                     n * sizeof(*m->m_info),
 303                                                     GFP_NOFS | __GFP_ZERO);
 304                         if (!new_m_info)
 305                                 goto nomem;
 306                         m->m_info = new_m_info;
 307                 }
 308                 m->m_num_mds = n;
 309         }
 310
 311         /* inc */
 312         __decode_and_drop_map(p, end, u32, u32, bad_ext);
 313         /* up */
 314         __decode_and_drop_map(p, end, u32, u64, bad_ext);
 315         /* failed */
 316         __decode_and_drop_set(p, end, u32, bad_ext);
 317         /* stopped */
 318         __decode_and_drop_set(p, end, u32, bad_ext);
 319
 320         if (mdsmap_ev >= 4) {
 321                 /* last_failure_osd_epoch */
 322                 __decode_and_drop_type(p, end, u32, bad_ext);
 323         }
 324         if (mdsmap_ev >= 6) {
 325                 /* ever_allowed_snaps */
 326                 __decode_and_drop_type(p, end, u8, bad_ext);
 327                 /* explicitly_allowed_snaps */
 328                 __decode_and_drop_type(p, end, u8, bad_ext);
 329         }
 330         if (mdsmap_ev >= 7) {
 331                 /* inline_data_enabled */
 332                 __decode_and_drop_type(p, end, u8, bad_ext);
 333         }
 334         if (mdsmap_ev >= 8) {
 335                 u32 name_len;
 336                 /* enabled */
 337                 ceph_decode_8_safe(p, end, m->m_enabled, bad_ext);
 338                 ceph_decode_32_safe(p, end, name_len, bad_ext);
 339                 ceph_decode_need(p, end, name_len, bad_ext);
 340                 *p += name_len;
 341         }
 342         /* damaged */
 343         if (mdsmap_ev >= 9) {
 344                 size_t need;
 345                 ceph_decode_32_safe(p, end, n, bad_ext);
 346                 need = sizeof(u32) * n;
 347                 ceph_decode_need(p, end, need, bad_ext);
 348                 *p += need;
 349                 m->m_damaged = n > 0;
 350         } else {
 351                 m->m_damaged = false;
 352         }
 353 bad_ext:
 354         *p = end;
 355         dout("mdsmap_decode success epoch %u\n", m->m_epoch);
 356         return m;
 357 nomem:
 358         err = -ENOMEM;
 359         goto out_err;
 360 bad:
 361         pr_err("corrupt mdsmap\n");
 362         print_hex_dump(KERN_DEBUG, "mdsmap: ",
 363                        DUMP_PREFIX_OFFSET, 16, 1,
 364                        start, end - start, true);
 365 out_err:
 366         ceph_mdsmap_destroy(m);
 367         return ERR_PTR(err);
 368 }
 369
 370 void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
 371 {
 372         int i;
 373
 374         for (i = 0; i < m->m_num_mds; i++)
 375                 kfree(m->m_info[i].export_targets);
 376         kfree(m->m_info);
 377         kfree(m->m_data_pg_pools);
 378         kfree(m);
 379 }
 380
 381 bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
 382 {
 383         int i, nr_active = 0;
 384         if (!m->m_enabled)
 385                 return false;
 386         if (m->m_damaged)
 387                 return false;
 388         if (m->m_num_laggy > 0)
 389                 return false;
 390         for (i = 0; i < m->m_num_mds; i++) {
 391                 if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
 392                         nr_active++;
 393         }
 394         return nr_active > 0;
 395 }