fs/ceph/mds_client.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/ceph/ceph_debug.h>
   3
   4 #include <linux/fs.h>
   5 #include <linux/wait.h>
   6 #include <linux/slab.h>
   7 #include <linux/gfp.h>
   8 #include <linux/sched.h>
   9 #include <linux/debugfs.h>
  10 #include <linux/seq_file.h>
  11 #include <linux/ratelimit.h>
  12 #include <linux/bits.h>
  13 #include <linux/ktime.h>
  14
  15 #include "super.h"
  16 #include "mds_client.h"
  17
  18 #include <linux/ceph/ceph_features.h>
  19 #include <linux/ceph/messenger.h>
  20 #include <linux/ceph/decode.h>
  21 #include <linux/ceph/pagelist.h>
  22 #include <linux/ceph/auth.h>
  23 #include <linux/ceph/debugfs.h>
  24
  25 #define RECONNECT_MAX_SIZE (INT_MAX - PAGE_SIZE)
  26
  27 /*
  28  * A cluster of MDS (metadata server) daemons is responsible for
  29  * managing the file system namespace (the directory hierarchy and
  30  * inodes) and for coordinating shared access to storage.  Metadata is
  31  * partitioning hierarchically across a number of servers, and that
  32  * partition varies over time as the cluster adjusts the distribution
  33  * in order to balance load.
  34  *
  35  * The MDS client is primarily responsible to managing synchronous
  36  * metadata requests for operations like open, unlink, and so forth.
  37  * If there is a MDS failure, we find out about it when we (possibly
  38  * request and) receive a new MDS map, and can resubmit affected
  39  * requests.
  40  *
  41  * For the most part, though, we take advantage of a lossless
  42  * communications channel to the MDS, and do not need to worry about
  43  * timing out or resubmitting requests.
  44  *
  45  * We maintain a stateful "session" with each MDS we interact with.
  46  * Within each session, we sent periodic heartbeat messages to ensure
  47  * any capabilities or leases we have been issues remain valid.  If
  48  * the session times out and goes stale, our leases and capabilities
  49  * are no longer valid.
  50  */
  51
  52 struct ceph_reconnect_state {
  53         struct ceph_mds_session *session;
  54         int nr_caps, nr_realms;
  55         struct ceph_pagelist *pagelist;
  56         unsigned msg_version;
  57         bool allow_multi;
  58 };
  59
  60 static void __wake_requests(struct ceph_mds_client *mdsc,
  61                             struct list_head *head);
  62 static void ceph_cap_release_work(struct work_struct *work);
  63 static void ceph_cap_reclaim_work(struct work_struct *work);
  64
  65 static const struct ceph_connection_operations mds_con_ops;
  66
  67
  68 /*
  69  * mds reply parsing
  70  */
  71
  72 static int parse_reply_info_quota(void **p, void *end,
  73                                   struct ceph_mds_reply_info_in *info)
  74 {
  75         u8 struct_v, struct_compat;
  76         u32 struct_len;
  77
  78         ceph_decode_8_safe(p, end, struct_v, bad);
  79         ceph_decode_8_safe(p, end, struct_compat, bad);
  80         /* struct_v is expected to be >= 1. we only
  81          * understand encoding with struct_compat == 1. */
  82         if (!struct_v || struct_compat != 1)
  83                 goto bad;
  84         ceph_decode_32_safe(p, end, struct_len, bad);
  85         ceph_decode_need(p, end, struct_len, bad);
  86         end = *p + struct_len;
  87         ceph_decode_64_safe(p, end, info->max_bytes, bad);
  88         ceph_decode_64_safe(p, end, info->max_files, bad);
  89         *p = end;
  90         return 0;
  91 bad:
  92         return -EIO;
  93 }
  94
  95 /*
  96  * parse individual inode info
  97  */
  98 static int parse_reply_info_in(void **p, void *end,
  99                                struct ceph_mds_reply_info_in *info,
 100                                u64 features)
 101 {
 102         int err = 0;
 103         u8 struct_v = 0;
 104
 105         if (features == (u64)-1) {
 106                 u32 struct_len;
 107                 u8 struct_compat;
 108                 ceph_decode_8_safe(p, end, struct_v, bad);
 109                 ceph_decode_8_safe(p, end, struct_compat, bad);
 110                 /* struct_v is expected to be >= 1. we only understand
 111                  * encoding with struct_compat == 1. */
 112                 if (!struct_v || struct_compat != 1)
 113                         goto bad;
 114                 ceph_decode_32_safe(p, end, struct_len, bad);
 115                 ceph_decode_need(p, end, struct_len, bad);
 116                 end = *p + struct_len;
 117         }
 118
 119         ceph_decode_need(p, end, sizeof(struct ceph_mds_reply_inode), bad);
 120         info->in = *p;
 121         *p += sizeof(struct ceph_mds_reply_inode) +
 122                 sizeof(*info->in->fragtree.splits) *
 123                 le32_to_cpu(info->in->fragtree.nsplits);
 124
 125         ceph_decode_32_safe(p, end, info->symlink_len, bad);
 126         ceph_decode_need(p, end, info->symlink_len, bad);
 127         info->symlink = *p;
 128         *p += info->symlink_len;
 129
 130         ceph_decode_copy_safe(p, end, &info->dir_layout,
 131                               sizeof(info->dir_layout), bad);
 132         ceph_decode_32_safe(p, end, info->xattr_len, bad);
 133         ceph_decode_need(p, end, info->xattr_len, bad);
 134         info->xattr_data = *p;
 135         *p += info->xattr_len;
 136
 137         if (features == (u64)-1) {
 138                 /* inline data */
 139                 ceph_decode_64_safe(p, end, info->inline_version, bad);
 140                 ceph_decode_32_safe(p, end, info->inline_len, bad);
 141                 ceph_decode_need(p, end, info->inline_len, bad);
 142                 info->inline_data = *p;
 143                 *p += info->inline_len;
 144                 /* quota */
 145                 err = parse_reply_info_quota(p, end, info);
 146                 if (err < 0)
 147                         goto out_bad;
 148                 /* pool namespace */
 149                 ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 150                 if (info->pool_ns_len > 0) {
 151                         ceph_decode_need(p, end, info->pool_ns_len, bad);
 152                         info->pool_ns_data = *p;
 153                         *p += info->pool_ns_len;
 154                 }
 155
 156                 /* btime */
 157                 ceph_decode_need(p, end, sizeof(info->btime), bad);
 158                 ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 159
 160                 /* change attribute */
 161                 ceph_decode_64_safe(p, end, info->change_attr, bad);
 162
 163                 /* dir pin */
 164                 if (struct_v >= 2) {
 165                         ceph_decode_32_safe(p, end, info->dir_pin, bad);
 166                 } else {
 167                         info->dir_pin = -ENODATA;
 168                 }
 169
 170                 /* snapshot birth time, remains zero for v<=2 */
 171                 if (struct_v >= 3) {
 172                         ceph_decode_need(p, end, sizeof(info->snap_btime), bad);
 173                         ceph_decode_copy(p, &info->snap_btime,
 174                                          sizeof(info->snap_btime));
 175                 } else {
 176                         memset(&info->snap_btime, 0, sizeof(info->snap_btime));
 177                 }
 178
 179                 *p = end;
 180         } else {
 181                 if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
 182                         ceph_decode_64_safe(p, end, info->inline_version, bad);
 183                         ceph_decode_32_safe(p, end, info->inline_len, bad);
 184                         ceph_decode_need(p, end, info->inline_len, bad);
 185                         info->inline_data = *p;
 186                         *p += info->inline_len;
 187                 } else
 188                         info->inline_version = CEPH_INLINE_NONE;
 189
 190                 if (features & CEPH_FEATURE_MDS_QUOTA) {
 191                         err = parse_reply_info_quota(p, end, info);
 192                         if (err < 0)
 193                                 goto out_bad;
 194                 } else {
 195                         info->max_bytes = 0;
 196                         info->max_files = 0;
 197                 }
 198
 199                 info->pool_ns_len = 0;
 200                 info->pool_ns_data = NULL;
 201                 if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 202                         ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 203                         if (info->pool_ns_len > 0) {
 204                                 ceph_decode_need(p, end, info->pool_ns_len, bad);
 205                                 info->pool_ns_data = *p;
 206                                 *p += info->pool_ns_len;
 207                         }
 208                 }
 209
 210                 if (features & CEPH_FEATURE_FS_BTIME) {
 211                         ceph_decode_need(p, end, sizeof(info->btime), bad);
 212                         ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 213                         ceph_decode_64_safe(p, end, info->change_attr, bad);
 214                 }
 215
 216                 info->dir_pin = -ENODATA;
 217                 /* info->snap_btime remains zero */
 218         }
 219         return 0;
 220 bad:
 221         err = -EIO;
 222 out_bad:
 223         return err;
 224 }
 225
 226 static int parse_reply_info_dir(void **p, void *end,
 227                                 struct ceph_mds_reply_dirfrag **dirfrag,
 228                                 u64 features)
 229 {
 230         if (features == (u64)-1) {
 231                 u8 struct_v, struct_compat;
 232                 u32 struct_len;
 233                 ceph_decode_8_safe(p, end, struct_v, bad);
 234                 ceph_decode_8_safe(p, end, struct_compat, bad);
 235                 /* struct_v is expected to be >= 1. we only understand
 236                  * encoding whose struct_compat == 1. */
 237                 if (!struct_v || struct_compat != 1)
 238                         goto bad;
 239                 ceph_decode_32_safe(p, end, struct_len, bad);
 240                 ceph_decode_need(p, end, struct_len, bad);
 241                 end = *p + struct_len;
 242         }
 243
 244         ceph_decode_need(p, end, sizeof(**dirfrag), bad);
 245         *dirfrag = *p;
 246         *p += sizeof(**dirfrag) + sizeof(u32) * le32_to_cpu((*dirfrag)->ndist);
 247         if (unlikely(*p > end))
 248                 goto bad;
 249         if (features == (u64)-1)
 250                 *p = end;
 251         return 0;
 252 bad:
 253         return -EIO;
 254 }
 255
 256 static int parse_reply_info_lease(void **p, void *end,
 257                                   struct ceph_mds_reply_lease **lease,
 258                                   u64 features)
 259 {
 260         if (features == (u64)-1) {
 261                 u8 struct_v, struct_compat;
 262                 u32 struct_len;
 263                 ceph_decode_8_safe(p, end, struct_v, bad);
 264                 ceph_decode_8_safe(p, end, struct_compat, bad);
 265                 /* struct_v is expected to be >= 1. we only understand
 266                  * encoding whose struct_compat == 1. */
 267                 if (!struct_v || struct_compat != 1)
 268                         goto bad;
 269                 ceph_decode_32_safe(p, end, struct_len, bad);
 270                 ceph_decode_need(p, end, struct_len, bad);
 271                 end = *p + struct_len;
 272         }
 273
 274         ceph_decode_need(p, end, sizeof(**lease), bad);
 275         *lease = *p;
 276         *p += sizeof(**lease);
 277         if (features == (u64)-1)
 278                 *p = end;
 279         return 0;
 280 bad:
 281         return -EIO;
 282 }
 283
 284 /*
 285  * parse a normal reply, which may contain a (dir+)dentry and/or a
 286  * target inode.
 287  */
 288 static int parse_reply_info_trace(void **p, void *end,
 289                                   struct ceph_mds_reply_info_parsed *info,
 290                                   u64 features)
 291 {
 292         int err;
 293
 294         if (info->head->is_dentry) {
 295                 err = parse_reply_info_in(p, end, &info->diri, features);
 296                 if (err < 0)
 297                         goto out_bad;
 298
 299                 err = parse_reply_info_dir(p, end, &info->dirfrag, features);
 300                 if (err < 0)
 301                         goto out_bad;
 302
 303                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 304                 ceph_decode_need(p, end, info->dname_len, bad);
 305                 info->dname = *p;
 306                 *p += info->dname_len;
 307
 308                 err = parse_reply_info_lease(p, end, &info->dlease, features);
 309                 if (err < 0)
 310                         goto out_bad;
 311         }
 312
 313         if (info->head->is_target) {
 314                 err = parse_reply_info_in(p, end, &info->targeti, features);
 315                 if (err < 0)
 316                         goto out_bad;
 317         }
 318
 319         if (unlikely(*p != end))
 320                 goto bad;
 321         return 0;
 322
 323 bad:
 324         err = -EIO;
 325 out_bad:
 326         pr_err("problem parsing mds trace %d\n", err);
 327         return err;
 328 }
 329
 330 /*
 331  * parse readdir results
 332  */
 333 static int parse_reply_info_readdir(void **p, void *end,
 334                                 struct ceph_mds_reply_info_parsed *info,
 335                                 u64 features)
 336 {
 337         u32 num, i = 0;
 338         int err;
 339
 340         err = parse_reply_info_dir(p, end, &info->dir_dir, features);
 341         if (err < 0)
 342                 goto out_bad;
 343
 344         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 345         num = ceph_decode_32(p);
 346         {
 347                 u16 flags = ceph_decode_16(p);
 348                 info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 349                 info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 350                 info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 351                 info->offset_hash = !!(flags & CEPH_READDIR_OFFSET_HASH);
 352         }
 353         if (num == 0)
 354                 goto done;
 355
 356         BUG_ON(!info->dir_entries);
 357         if ((unsigned long)(info->dir_entries + num) >
 358             (unsigned long)info->dir_entries + info->dir_buf_size) {
 359                 pr_err("dir contents are larger than expected\n");
 360                 WARN_ON(1);
 361                 goto bad;
 362         }
 363
 364         info->dir_nr = num;
 365         while (num) {
 366                 struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 367                 /* dentry */
 368                 ceph_decode_32_safe(p, end, rde->name_len, bad);
 369                 ceph_decode_need(p, end, rde->name_len, bad);
 370                 rde->name = *p;
 371                 *p += rde->name_len;
 372                 dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 373
 374                 /* dentry lease */
 375                 err = parse_reply_info_lease(p, end, &rde->lease, features);
 376                 if (err)
 377                         goto out_bad;
 378                 /* inode */
 379                 err = parse_reply_info_in(p, end, &rde->inode, features);
 380                 if (err < 0)
 381                         goto out_bad;
 382                 /* ceph_readdir_prepopulate() will update it */
 383                 rde->offset = 0;
 384                 i++;
 385                 num--;
 386         }
 387
 388 done:
 389         /* Skip over any unrecognized fields */
 390         *p = end;
 391         return 0;
 392
 393 bad:
 394         err = -EIO;
 395 out_bad:
 396         pr_err("problem parsing dir contents %d\n", err);
 397         return err;
 398 }
 399
 400 /*
 401  * parse fcntl F_GETLK results
 402  */
 403 static int parse_reply_info_filelock(void **p, void *end,
 404                                      struct ceph_mds_reply_info_parsed *info,
 405                                      u64 features)
 406 {
 407         if (*p + sizeof(*info->filelock_reply) > end)
 408                 goto bad;
 409
 410         info->filelock_reply = *p;
 411
 412         /* Skip over any unrecognized fields */
 413         *p = end;
 414         return 0;
 415 bad:
 416         return -EIO;
 417 }
 418
 419
 420 #if BITS_PER_LONG == 64
 421
 422 #define DELEGATED_INO_AVAILABLE         xa_mk_value(1)
 423
 424 static int ceph_parse_deleg_inos(void **p, void *end,
 425                                  struct ceph_mds_session *s)
 426 {
 427         u32 sets;
 428
 429         ceph_decode_32_safe(p, end, sets, bad);
 430         dout("got %u sets of delegated inodes\n", sets);
 431         while (sets--) {
 432                 u64 start, len, ino;
 433
 434                 ceph_decode_64_safe(p, end, start, bad);
 435                 ceph_decode_64_safe(p, end, len, bad);
 436                 while (len--) {
 437                         int err = xa_insert(&s->s_delegated_inos, ino = start++,
 438                                             DELEGATED_INO_AVAILABLE,
 439                                             GFP_KERNEL);
 440                         if (!err) {
 441                                 dout("added delegated inode 0x%llx\n",
 442                                      start - 1);
 443                         } else if (err == -EBUSY) {
 444                                 pr_warn("ceph: MDS delegated inode 0x%llx more than once.\n",
 445                                         start - 1);
 446                         } else {
 447                                 return err;
 448                         }
 449                 }
 450         }
 451         return 0;
 452 bad:
 453         return -EIO;
 454 }
 455
 456 u64 ceph_get_deleg_ino(struct ceph_mds_session *s)
 457 {
 458         unsigned long ino;
 459         void *val;
 460
 461         xa_for_each(&s->s_delegated_inos, ino, val) {
 462                 val = xa_erase(&s->s_delegated_inos, ino);
 463                 if (val == DELEGATED_INO_AVAILABLE)
 464                         return ino;
 465         }
 466         return 0;
 467 }
 468
 469 int ceph_restore_deleg_ino(struct ceph_mds_session *s, u64 ino)
 470 {
 471         return xa_insert(&s->s_delegated_inos, ino, DELEGATED_INO_AVAILABLE,
 472                          GFP_KERNEL);
 473 }
 474 #else /* BITS_PER_LONG == 64 */
 475 /*
 476  * FIXME: xarrays can't handle 64-bit indexes on a 32-bit arch. For now, just
 477  * ignore delegated_inos on 32 bit arch. Maybe eventually add xarrays for top
 478  * and bottom words?
 479  */
 480 static int ceph_parse_deleg_inos(void **p, void *end,
 481                                  struct ceph_mds_session *s)
 482 {
 483         u32 sets;
 484
 485         ceph_decode_32_safe(p, end, sets, bad);
 486         if (sets)
 487                 ceph_decode_skip_n(p, end, sets * 2 * sizeof(__le64), bad);
 488         return 0;
 489 bad:
 490         return -EIO;
 491 }
 492
 493 u64 ceph_get_deleg_ino(struct ceph_mds_session *s)
 494 {
 495         return 0;
 496 }
 497
 498 int ceph_restore_deleg_ino(struct ceph_mds_session *s, u64 ino)
 499 {
 500         return 0;
 501 }
 502 #endif /* BITS_PER_LONG == 64 */
 503
 504 /*
 505  * parse create results
 506  */
 507 static int parse_reply_info_create(void **p, void *end,
 508                                   struct ceph_mds_reply_info_parsed *info,
 509                                   u64 features, struct ceph_mds_session *s)
 510 {
 511         int ret;
 512
 513         if (features == (u64)-1 ||
 514             (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
 515                 if (*p == end) {
 516                         /* Malformed reply? */
 517                         info->has_create_ino = false;
 518                 } else if (test_bit(CEPHFS_FEATURE_DELEG_INO, &s->s_features)) {
 519                         info->has_create_ino = true;
 520                         /* struct_v, struct_compat, and len */
 521                         ceph_decode_skip_n(p, end, 2 + sizeof(u32), bad);
 522                         ceph_decode_64_safe(p, end, info->ino, bad);
 523                         ret = ceph_parse_deleg_inos(p, end, s);
 524                         if (ret)
 525                                 return ret;
 526                 } else {
 527                         /* legacy */
 528                         ceph_decode_64_safe(p, end, info->ino, bad);
 529                         info->has_create_ino = true;
 530                 }
 531         } else {
 532                 if (*p != end)
 533                         goto bad;
 534         }
 535
 536         /* Skip over any unrecognized fields */
 537         *p = end;
 538         return 0;
 539 bad:
 540         return -EIO;
 541 }
 542
 543 /*
 544  * parse extra results
 545  */
 546 static int parse_reply_info_extra(void **p, void *end,
 547                                   struct ceph_mds_reply_info_parsed *info,
 548                                   u64 features, struct ceph_mds_session *s)
 549 {
 550         u32 op = le32_to_cpu(info->head->op);
 551
 552         if (op == CEPH_MDS_OP_GETFILELOCK)
 553                 return parse_reply_info_filelock(p, end, info, features);
 554         else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 555                 return parse_reply_info_readdir(p, end, info, features);
 556         else if (op == CEPH_MDS_OP_CREATE)
 557                 return parse_reply_info_create(p, end, info, features, s);
 558         else
 559                 return -EIO;
 560 }
 561
 562 /*
 563  * parse entire mds reply
 564  */
 565 static int parse_reply_info(struct ceph_mds_session *s, struct ceph_msg *msg,
 566                             struct ceph_mds_reply_info_parsed *info,
 567                             u64 features)
 568 {
 569         void *p, *end;
 570         u32 len;
 571         int err;
 572
 573         info->head = msg->front.iov_base;
 574         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 575         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 576
 577         /* trace */
 578         ceph_decode_32_safe(&p, end, len, bad);
 579         if (len > 0) {
 580                 ceph_decode_need(&p, end, len, bad);
 581                 err = parse_reply_info_trace(&p, p+len, info, features);
 582                 if (err < 0)
 583                         goto out_bad;
 584         }
 585
 586         /* extra */
 587         ceph_decode_32_safe(&p, end, len, bad);
 588         if (len > 0) {
 589                 ceph_decode_need(&p, end, len, bad);
 590                 err = parse_reply_info_extra(&p, p+len, info, features, s);
 591                 if (err < 0)
 592                         goto out_bad;
 593         }
 594
 595         /* snap blob */
 596         ceph_decode_32_safe(&p, end, len, bad);
 597         info->snapblob_len = len;
 598         info->snapblob = p;
 599         p += len;
 600
 601         if (p != end)
 602                 goto bad;
 603         return 0;
 604
 605 bad:
 606         err = -EIO;
 607 out_bad:
 608         pr_err("mds parse_reply err %d\n", err);
 609         return err;
 610 }
 611
 612 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 613 {
 614         if (!info->dir_entries)
 615                 return;
 616         free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 617 }
 618
 619
 620 /*
 621  * sessions
 622  */
 623 const char *ceph_session_state_name(int s)
 624 {
 625         switch (s) {
 626         case CEPH_MDS_SESSION_NEW: return "new";
 627         case CEPH_MDS_SESSION_OPENING: return "opening";
 628         case CEPH_MDS_SESSION_OPEN: return "open";
 629         case CEPH_MDS_SESSION_HUNG: return "hung";
 630         case CEPH_MDS_SESSION_CLOSING: return "closing";
 631         case CEPH_MDS_SESSION_CLOSED: return "closed";
 632         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 633         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 634         case CEPH_MDS_SESSION_REJECTED: return "rejected";
 635         default: return "???";
 636         }
 637 }
 638
 639 struct ceph_mds_session *ceph_get_mds_session(struct ceph_mds_session *s)
 640 {
 641         if (refcount_inc_not_zero(&s->s_ref)) {
 642                 dout("mdsc get_session %p %d -> %d\n", s,
 643                      refcount_read(&s->s_ref)-1, refcount_read(&s->s_ref));
 644                 return s;
 645         } else {
 646                 dout("mdsc get_session %p 0 -- FAIL\n", s);
 647                 return NULL;
 648         }
 649 }
 650
 651 void ceph_put_mds_session(struct ceph_mds_session *s)
 652 {
 653         dout("mdsc put_session %p %d -> %d\n", s,
 654              refcount_read(&s->s_ref), refcount_read(&s->s_ref)-1);
 655         if (refcount_dec_and_test(&s->s_ref)) {
 656                 if (s->s_auth.authorizer)
 657                         ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 658                 WARN_ON(mutex_is_locked(&s->s_mutex));
 659                 xa_destroy(&s->s_delegated_inos);
 660                 kfree(s);
 661         }
 662 }
 663
 664 /*
 665  * called under mdsc->mutex
 666  */
 667 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 668                                                    int mds)
 669 {
 670         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 671                 return NULL;
 672         return ceph_get_mds_session(mdsc->sessions[mds]);
 673 }
 674
 675 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 676 {
 677         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 678                 return false;
 679         else
 680                 return true;
 681 }
 682
 683 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 684                                        struct ceph_mds_session *s)
 685 {
 686         if (s->s_mds >= mdsc->max_sessions ||
 687             mdsc->sessions[s->s_mds] != s)
 688                 return -ENOENT;
 689         return 0;
 690 }
 691
 692 /*
 693  * create+register a new session for given mds.
 694  * called under mdsc->mutex.
 695  */
 696 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 697                                                  int mds)
 698 {
 699         struct ceph_mds_session *s;
 700
 701         if (mds >= mdsc->mdsmap->possible_max_rank)
 702                 return ERR_PTR(-EINVAL);
 703
 704         s = kzalloc(sizeof(*s), GFP_NOFS);
 705         if (!s)
 706                 return ERR_PTR(-ENOMEM);
 707
 708         if (mds >= mdsc->max_sessions) {
 709                 int newmax = 1 << get_count_order(mds + 1);
 710                 struct ceph_mds_session **sa;
 711
 712                 dout("%s: realloc to %d\n", __func__, newmax);
 713                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 714                 if (!sa)
 715                         goto fail_realloc;
 716                 if (mdsc->sessions) {
 717                         memcpy(sa, mdsc->sessions,
 718                                mdsc->max_sessions * sizeof(void *));
 719                         kfree(mdsc->sessions);
 720                 }
 721                 mdsc->sessions = sa;
 722                 mdsc->max_sessions = newmax;
 723         }
 724
 725         dout("%s: mds%d\n", __func__, mds);
 726         s->s_mdsc = mdsc;
 727         s->s_mds = mds;
 728         s->s_state = CEPH_MDS_SESSION_NEW;
 729         s->s_ttl = 0;
 730         s->s_seq = 0;
 731         mutex_init(&s->s_mutex);
 732
 733         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 734
 735         spin_lock_init(&s->s_gen_ttl_lock);
 736         s->s_cap_gen = 1;
 737         s->s_cap_ttl = jiffies - 1;
 738
 739         spin_lock_init(&s->s_cap_lock);
 740         s->s_renew_requested = 0;
 741         s->s_renew_seq = 0;
 742         INIT_LIST_HEAD(&s->s_caps);
 743         s->s_nr_caps = 0;
 744         refcount_set(&s->s_ref, 1);
 745         INIT_LIST_HEAD(&s->s_waiting);
 746         INIT_LIST_HEAD(&s->s_unsafe);
 747         xa_init(&s->s_delegated_inos);
 748         s->s_num_cap_releases = 0;
 749         s->s_cap_reconnect = 0;
 750         s->s_cap_iterator = NULL;
 751         INIT_LIST_HEAD(&s->s_cap_releases);
 752         INIT_WORK(&s->s_cap_release_work, ceph_cap_release_work);
 753
 754         INIT_LIST_HEAD(&s->s_cap_dirty);
 755         INIT_LIST_HEAD(&s->s_cap_flushing);
 756
 757         mdsc->sessions[mds] = s;
 758         atomic_inc(&mdsc->num_sessions);
 759         refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 760
 761         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 762                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 763
 764         return s;
 765
 766 fail_realloc:
 767         kfree(s);
 768         return ERR_PTR(-ENOMEM);
 769 }
 770
 771 /*
 772  * called under mdsc->mutex
 773  */
 774 static void __unregister_session(struct ceph_mds_client *mdsc,
 775                                struct ceph_mds_session *s)
 776 {
 777         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 778         BUG_ON(mdsc->sessions[s->s_mds] != s);
 779         mdsc->sessions[s->s_mds] = NULL;
 780         ceph_con_close(&s->s_con);
 781         ceph_put_mds_session(s);
 782         atomic_dec(&mdsc->num_sessions);
 783 }
 784
 785 /*
 786  * drop session refs in request.
 787  *
 788  * should be last request ref, or hold mdsc->mutex
 789  */
 790 static void put_request_session(struct ceph_mds_request *req)
 791 {
 792         if (req->r_session) {
 793                 ceph_put_mds_session(req->r_session);
 794                 req->r_session = NULL;
 795         }
 796 }
 797
 798 void ceph_mdsc_release_request(struct kref *kref)
 799 {
 800         struct ceph_mds_request *req = container_of(kref,
 801                                                     struct ceph_mds_request,
 802                                                     r_kref);
 803         ceph_mdsc_release_dir_caps_no_check(req);
 804         destroy_reply_info(&req->r_reply_info);
 805         if (req->r_request)
 806                 ceph_msg_put(req->r_request);
 807         if (req->r_reply)
 808                 ceph_msg_put(req->r_reply);
 809         if (req->r_inode) {
 810                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 811                 /* avoid calling iput_final() in mds dispatch threads */
 812                 ceph_async_iput(req->r_inode);
 813         }
 814         if (req->r_parent) {
 815                 ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
 816                 ceph_async_iput(req->r_parent);
 817         }
 818         ceph_async_iput(req->r_target_inode);
 819         if (req->r_dentry)
 820                 dput(req->r_dentry);
 821         if (req->r_old_dentry)
 822                 dput(req->r_old_dentry);
 823         if (req->r_old_dentry_dir) {
 824                 /*
 825                  * track (and drop pins for) r_old_dentry_dir
 826                  * separately, since r_old_dentry's d_parent may have
 827                  * changed between the dir mutex being dropped and
 828                  * this request being freed.
 829                  */
 830                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 831                                   CEPH_CAP_PIN);
 832                 ceph_async_iput(req->r_old_dentry_dir);
 833         }
 834         kfree(req->r_path1);
 835         kfree(req->r_path2);
 836         put_cred(req->r_cred);
 837         if (req->r_pagelist)
 838                 ceph_pagelist_release(req->r_pagelist);
 839         put_request_session(req);
 840         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 841         WARN_ON_ONCE(!list_empty(&req->r_wait));
 842         kmem_cache_free(ceph_mds_request_cachep, req);
 843 }
 844
 845 DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 846
 847 /*
 848  * lookup session, bump ref if found.
 849  *
 850  * called under mdsc->mutex.
 851  */
 852 static struct ceph_mds_request *
 853 lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 854 {
 855         struct ceph_mds_request *req;
 856
 857         req = lookup_request(&mdsc->request_tree, tid);
 858         if (req)
 859                 ceph_mdsc_get_request(req);
 860
 861         return req;
 862 }
 863
 864 /*
 865  * Register an in-flight request, and assign a tid.  Link to directory
 866  * are modifying (if any).
 867  *
 868  * Called under mdsc->mutex.
 869  */
 870 static void __register_request(struct ceph_mds_client *mdsc,
 871                                struct ceph_mds_request *req,
 872                                struct inode *dir)
 873 {
 874         int ret = 0;
 875
 876         req->r_tid = ++mdsc->last_tid;
 877         if (req->r_num_caps) {
 878                 ret = ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 879                                         req->r_num_caps);
 880                 if (ret < 0) {
 881                         pr_err("__register_request %p "
 882                                "failed to reserve caps: %d\n", req, ret);
 883                         /* set req->r_err to fail early from __do_request */
 884                         req->r_err = ret;
 885                         return;
 886                 }
 887         }
 888         dout("__register_request %p tid %lld\n", req, req->r_tid);
 889         ceph_mdsc_get_request(req);
 890         insert_request(&mdsc->request_tree, req);
 891
 892         req->r_cred = get_current_cred();
 893
 894         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 895                 mdsc->oldest_tid = req->r_tid;
 896
 897         if (dir) {
 898                 struct ceph_inode_info *ci = ceph_inode(dir);
 899
 900                 ihold(dir);
 901                 req->r_unsafe_dir = dir;
 902                 spin_lock(&ci->i_unsafe_lock);
 903                 list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 904                 spin_unlock(&ci->i_unsafe_lock);
 905         }
 906 }
 907
 908 static void __unregister_request(struct ceph_mds_client *mdsc,
 909                                  struct ceph_mds_request *req)
 910 {
 911         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 912
 913         /* Never leave an unregistered request on an unsafe list! */
 914         list_del_init(&req->r_unsafe_item);
 915
 916         if (req->r_tid == mdsc->oldest_tid) {
 917                 struct rb_node *p = rb_next(&req->r_node);
 918                 mdsc->oldest_tid = 0;
 919                 while (p) {
 920                         struct ceph_mds_request *next_req =
 921                                 rb_entry(p, struct ceph_mds_request, r_node);
 922                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 923                                 mdsc->oldest_tid = next_req->r_tid;
 924                                 break;
 925                         }
 926                         p = rb_next(p);
 927                 }
 928         }
 929
 930         erase_request(&mdsc->request_tree, req);
 931
 932         if (req->r_unsafe_dir) {
 933                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 934                 spin_lock(&ci->i_unsafe_lock);
 935                 list_del_init(&req->r_unsafe_dir_item);
 936                 spin_unlock(&ci->i_unsafe_lock);
 937         }
 938         if (req->r_target_inode &&
 939             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 940                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 941                 spin_lock(&ci->i_unsafe_lock);
 942                 list_del_init(&req->r_unsafe_target_item);
 943                 spin_unlock(&ci->i_unsafe_lock);
 944         }
 945
 946         if (req->r_unsafe_dir) {
 947                 /* avoid calling iput_final() in mds dispatch threads */
 948                 ceph_async_iput(req->r_unsafe_dir);
 949                 req->r_unsafe_dir = NULL;
 950         }
 951
 952         complete_all(&req->r_safe_completion);
 953
 954         ceph_mdsc_put_request(req);
 955 }
 956
 957 /*
 958  * Walk back up the dentry tree until we hit a dentry representing a
 959  * non-snapshot inode. We do this using the rcu_read_lock (which must be held
 960  * when calling this) to ensure that the objects won't disappear while we're
 961  * working with them. Once we hit a candidate dentry, we attempt to take a
 962  * reference to it, and return that as the result.
 963  */
 964 static struct inode *get_nonsnap_parent(struct dentry *dentry)
 965 {
 966         struct inode *inode = NULL;
 967
 968         while (dentry && !IS_ROOT(dentry)) {
 969                 inode = d_inode_rcu(dentry);
 970                 if (!inode || ceph_snap(inode) == CEPH_NOSNAP)
 971                         break;
 972                 dentry = dentry->d_parent;
 973         }
 974         if (inode)
 975                 inode = igrab(inode);
 976         return inode;
 977 }
 978
 979 /*
 980  * Choose mds to send request to next.  If there is a hint set in the
 981  * request (e.g., due to a prior forward hint from the mds), use that.
 982  * Otherwise, consult frag tree and/or caps to identify the
 983  * appropriate mds.  If all else fails, choose randomly.
 984  *
 985  * Called under mdsc->mutex.
 986  */
 987 static int __choose_mds(struct ceph_mds_client *mdsc,
 988                         struct ceph_mds_request *req,
 989                         bool *random)
 990 {
 991         struct inode *inode;
 992         struct ceph_inode_info *ci;
 993         struct ceph_cap *cap;
 994         int mode = req->r_direct_mode;
 995         int mds = -1;
 996         u32 hash = req->r_direct_hash;
 997         bool is_hash = test_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
 998
 999         if (random)
1000                 *random = false;
1001
1002         /*
1003          * is there a specific mds we should try?  ignore hint if we have
1004          * no session and the mds is not up (active or recovering).
1005          */
1006         if (req->r_resend_mds >= 0 &&
1007             (__have_session(mdsc, req->r_resend_mds) ||
1008              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
1009                 dout("%s using resend_mds mds%d\n", __func__,
1010                      req->r_resend_mds);
1011                 return req->r_resend_mds;
1012         }
1013
1014         if (mode == USE_RANDOM_MDS)
1015                 goto random;
1016
1017         inode = NULL;
1018         if (req->r_inode) {
1019                 if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
1020                         inode = req->r_inode;
1021                         ihold(inode);
1022                 } else {
1023                         /* req->r_dentry is non-null for LSSNAP request */
1024                         rcu_read_lock();
1025                         inode = get_nonsnap_parent(req->r_dentry);
1026                         rcu_read_unlock();
1027                         dout("%s using snapdir's parent %p\n", __func__, inode);
1028                 }
1029         } else if (req->r_dentry) {
1030                 /* ignore race with rename; old or new d_parent is okay */
1031                 struct dentry *parent;
1032                 struct inode *dir;
1033
1034                 rcu_read_lock();
1035                 parent = READ_ONCE(req->r_dentry->d_parent);
1036                 dir = req->r_parent ? : d_inode_rcu(parent);
1037
1038                 if (!dir || dir->i_sb != mdsc->fsc->sb) {
1039                         /*  not this fs or parent went negative */
1040                         inode = d_inode(req->r_dentry);
1041                         if (inode)
1042                                 ihold(inode);
1043                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
1044                         /* direct snapped/virtual snapdir requests
1045                          * based on parent dir inode */
1046                         inode = get_nonsnap_parent(parent);
1047                         dout("%s using nonsnap parent %p\n", __func__, inode);
1048                 } else {
1049                         /* dentry target */
1050                         inode = d_inode(req->r_dentry);
1051                         if (!inode || mode == USE_AUTH_MDS) {
1052                                 /* dir + name */
1053                                 inode = igrab(dir);
1054                                 hash = ceph_dentry_hash(dir, req->r_dentry);
1055                                 is_hash = true;
1056                         } else {
1057                                 ihold(inode);
1058                         }
1059                 }
1060                 rcu_read_unlock();
1061         }
1062
1063         dout("%s %p is_hash=%d (0x%x) mode %d\n", __func__, inode, (int)is_hash,
1064              hash, mode);
1065         if (!inode)
1066                 goto random;
1067         ci = ceph_inode(inode);
1068
1069         if (is_hash && S_ISDIR(inode->i_mode)) {
1070                 struct ceph_inode_frag frag;
1071                 int found;
1072
1073                 ceph_choose_frag(ci, hash, &frag, &found);
1074                 if (found) {
1075                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
1076                                 u8 r;
1077
1078                                 /* choose a random replica */
1079                                 get_random_bytes(&r, 1);
1080                                 r %= frag.ndist;
1081                                 mds = frag.dist[r];
1082                                 dout("%s %p %llx.%llx frag %u mds%d (%d/%d)\n",
1083                                      __func__, inode, ceph_vinop(inode),
1084                                      frag.frag, mds, (int)r, frag.ndist);
1085                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
1086                                     CEPH_MDS_STATE_ACTIVE &&
1087                                     !ceph_mdsmap_is_laggy(mdsc->mdsmap, mds))
1088                                         goto out;
1089                         }
1090
1091                         /* since this file/dir wasn't known to be
1092                          * replicated, then we want to look for the
1093                          * authoritative mds. */
1094                         if (frag.mds >= 0) {
1095                                 /* choose auth mds */
1096                                 mds = frag.mds;
1097                                 dout("%s %p %llx.%llx frag %u mds%d (auth)\n",
1098                                      __func__, inode, ceph_vinop(inode),
1099                                      frag.frag, mds);
1100                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
1101                                     CEPH_MDS_STATE_ACTIVE) {
1102                                         if (!ceph_mdsmap_is_laggy(mdsc->mdsmap,
1103                                                                   mds))
1104                                                 goto out;
1105                                 }
1106                         }
1107                         mode = USE_AUTH_MDS;
1108                 }
1109         }
1110
1111         spin_lock(&ci->i_ceph_lock);
1112         cap = NULL;
1113         if (mode == USE_AUTH_MDS)
1114                 cap = ci->i_auth_cap;
1115         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
1116                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
1117         if (!cap) {
1118                 spin_unlock(&ci->i_ceph_lock);
1119                 ceph_async_iput(inode);
1120                 goto random;
1121         }
1122         mds = cap->session->s_mds;
1123         dout("%s %p %llx.%llx mds%d (%scap %p)\n", __func__,
1124              inode, ceph_vinop(inode), mds,
1125              cap == ci->i_auth_cap ? "auth " : "", cap);
1126         spin_unlock(&ci->i_ceph_lock);
1127 out:
1128         /* avoid calling iput_final() while holding mdsc->mutex or
1129          * in mds dispatch threads */
1130         ceph_async_iput(inode);
1131         return mds;
1132
1133 random:
1134         if (random)
1135                 *random = true;
1136
1137         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
1138         dout("%s chose random mds%d\n", __func__, mds);
1139         return mds;
1140 }
1141
1142
1143 /*
1144  * session messages
1145  */
1146 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
1147 {
1148         struct ceph_msg *msg;
1149         struct ceph_mds_session_head *h;
1150
1151         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
1152                            false);
1153         if (!msg) {
1154                 pr_err("create_session_msg ENOMEM creating msg\n");
1155                 return NULL;
1156         }
1157         h = msg->front.iov_base;
1158         h->op = cpu_to_le32(op);
1159         h->seq = cpu_to_le64(seq);
1160
1161         return msg;
1162 }
1163
1164 static const unsigned char feature_bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
1165 #define FEATURE_BYTES(c) (DIV_ROUND_UP((size_t)feature_bits[c - 1] + 1, 64) * 8)
1166 static int encode_supported_features(void **p, void *end)
1167 {
1168         static const size_t count = ARRAY_SIZE(feature_bits);
1169
1170         if (count > 0) {
1171                 size_t i;
1172                 size_t size = FEATURE_BYTES(count);
1173
1174                 if (WARN_ON_ONCE(*p + 4 + size > end))
1175                         return -ERANGE;
1176
1177                 ceph_encode_32(p, size);
1178                 memset(*p, 0, size);
1179                 for (i = 0; i < count; i++)
1180                         ((unsigned char*)(*p))[i / 8] |= BIT(feature_bits[i] % 8);
1181                 *p += size;
1182         } else {
1183                 if (WARN_ON_ONCE(*p + 4 > end))
1184                         return -ERANGE;
1185
1186                 ceph_encode_32(p, 0);
1187         }
1188
1189         return 0;
1190 }
1191
1192 static const unsigned char metric_bits[] = CEPHFS_METRIC_SPEC_CLIENT_SUPPORTED;
1193 #define METRIC_BYTES(cnt) (DIV_ROUND_UP((size_t)metric_bits[cnt - 1] + 1, 64) * 8)
1194 static int encode_metric_spec(void **p, void *end)
1195 {
1196         static const size_t count = ARRAY_SIZE(metric_bits);
1197
1198         /* header */
1199         if (WARN_ON_ONCE(*p + 2 > end))
1200                 return -ERANGE;
1201
1202         ceph_encode_8(p, 1); /* version */
1203         ceph_encode_8(p, 1); /* compat */
1204
1205         if (count > 0) {
1206                 size_t i;
1207                 size_t size = METRIC_BYTES(count);
1208
1209                 if (WARN_ON_ONCE(*p + 4 + 4 + size > end))
1210                         return -ERANGE;
1211
1212                 /* metric spec info length */
1213                 ceph_encode_32(p, 4 + size);
1214
1215                 /* metric spec */
1216                 ceph_encode_32(p, size);
1217                 memset(*p, 0, size);
1218                 for (i = 0; i < count; i++)
1219                         ((unsigned char *)(*p))[i / 8] |= BIT(metric_bits[i] % 8);
1220                 *p += size;
1221         } else {
1222                 if (WARN_ON_ONCE(*p + 4 + 4 > end))
1223                         return -ERANGE;
1224
1225                 /* metric spec info length */
1226                 ceph_encode_32(p, 4);
1227                 /* metric spec */
1228                 ceph_encode_32(p, 0);
1229         }
1230
1231         return 0;
1232 }
1233
1234 /*
1235  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
1236  * to include additional client metadata fields.
1237  */
1238 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
1239 {
1240         struct ceph_msg *msg;
1241         struct ceph_mds_session_head *h;
1242         int i;
1243         int extra_bytes = 0;
1244         int metadata_key_count = 0;
1245         struct ceph_options *opt = mdsc->fsc->client->options;
1246         struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
1247         size_t size, count;
1248         void *p, *end;
1249         int ret;
1250
1251         const char* metadata[][2] = {
1252                 {"hostname", mdsc->nodename},
1253                 {"kernel_version", init_utsname()->release},
1254                 {"entity_id", opt->name ? : ""},
1255                 {"root", fsopt->server_path ? : "/"},
1256                 {NULL, NULL}
1257         };
1258
1259         /* Calculate serialized length of metadata */
1260         extra_bytes = 4;  /* map length */
1261         for (i = 0; metadata[i][0]; ++i) {
1262                 extra_bytes += 8 + strlen(metadata[i][0]) +
1263                         strlen(metadata[i][1]);
1264                 metadata_key_count++;
1265         }
1266
1267         /* supported feature */
1268         size = 0;
1269         count = ARRAY_SIZE(feature_bits);
1270         if (count > 0)
1271                 size = FEATURE_BYTES(count);
1272         extra_bytes += 4 + size;
1273
1274         /* metric spec */
1275         size = 0;
1276         count = ARRAY_SIZE(metric_bits);
1277         if (count > 0)
1278                 size = METRIC_BYTES(count);
1279         extra_bytes += 2 + 4 + 4 + size;
1280
1281         /* Allocate the message */
1282         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + extra_bytes,
1283                            GFP_NOFS, false);
1284         if (!msg) {
1285                 pr_err("create_session_msg ENOMEM creating msg\n");
1286                 return ERR_PTR(-ENOMEM);
1287         }
1288         p = msg->front.iov_base;
1289         end = p + msg->front.iov_len;
1290
1291         h = p;
1292         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
1293         h->seq = cpu_to_le64(seq);
1294
1295         /*
1296          * Serialize client metadata into waiting buffer space, using
1297          * the format that userspace expects for map<string, string>
1298          *
1299          * ClientSession messages with metadata are v4
1300          */
1301         msg->hdr.version = cpu_to_le16(4);
1302         msg->hdr.compat_version = cpu_to_le16(1);
1303
1304         /* The write pointer, following the session_head structure */
1305         p += sizeof(*h);
1306
1307         /* Number of entries in the map */
1308         ceph_encode_32(&p, metadata_key_count);
1309
1310         /* Two length-prefixed strings for each entry in the map */
1311         for (i = 0; metadata[i][0]; ++i) {
1312                 size_t const key_len = strlen(metadata[i][0]);
1313                 size_t const val_len = strlen(metadata[i][1]);
1314
1315                 ceph_encode_32(&p, key_len);
1316                 memcpy(p, metadata[i][0], key_len);
1317                 p += key_len;
1318                 ceph_encode_32(&p, val_len);
1319                 memcpy(p, metadata[i][1], val_len);
1320                 p += val_len;
1321         }
1322
1323         ret = encode_supported_features(&p, end);
1324         if (ret) {
1325                 pr_err("encode_supported_features failed!\n");
1326                 ceph_msg_put(msg);
1327                 return ERR_PTR(ret);
1328         }
1329
1330         ret = encode_metric_spec(&p, end);
1331         if (ret) {
1332                 pr_err("encode_metric_spec failed!\n");
1333                 ceph_msg_put(msg);
1334                 return ERR_PTR(ret);
1335         }
1336
1337         msg->front.iov_len = p - msg->front.iov_base;
1338         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1339
1340         return msg;
1341 }
1342
1343 /*
1344  * send session open request.
1345  *
1346  * called under mdsc->mutex
1347  */
1348 static int __open_session(struct ceph_mds_client *mdsc,
1349                           struct ceph_mds_session *session)
1350 {
1351         struct ceph_msg *msg;
1352         int mstate;
1353         int mds = session->s_mds;
1354
1355         /* wait for mds to go active? */
1356         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
1357         dout("open_session to mds%d (%s)\n", mds,
1358              ceph_mds_state_name(mstate));
1359         session->s_state = CEPH_MDS_SESSION_OPENING;
1360         session->s_renew_requested = jiffies;
1361
1362         /* send connect message */
1363         msg = create_session_open_msg(mdsc, session->s_seq);
1364         if (IS_ERR(msg))
1365                 return PTR_ERR(msg);
1366         ceph_con_send(&session->s_con, msg);
1367         return 0;
1368 }
1369
1370 /*
1371  * open sessions for any export targets for the given mds
1372  *
1373  * called under mdsc->mutex
1374  */
1375 static struct ceph_mds_session *
1376 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
1377 {
1378         struct ceph_mds_session *session;
1379         int ret;
1380
1381         session = __ceph_lookup_mds_session(mdsc, target);
1382         if (!session) {
1383                 session = register_session(mdsc, target);
1384                 if (IS_ERR(session))
1385                         return session;
1386         }
1387         if (session->s_state == CEPH_MDS_SESSION_NEW ||
1388             session->s_state == CEPH_MDS_SESSION_CLOSING) {
1389                 ret = __open_session(mdsc, session);
1390                 if (ret)
1391                         return ERR_PTR(ret);
1392         }
1393
1394         return session;
1395 }
1396
1397 struct ceph_mds_session *
1398 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
1399 {
1400         struct ceph_mds_session *session;
1401
1402         dout("open_export_target_session to mds%d\n", target);
1403
1404         mutex_lock(&mdsc->mutex);
1405         session = __open_export_target_session(mdsc, target);
1406         mutex_unlock(&mdsc->mutex);
1407
1408         return session;
1409 }
1410
1411 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
1412                                           struct ceph_mds_session *session)
1413 {
1414         struct ceph_mds_info *mi;
1415         struct ceph_mds_session *ts;
1416         int i, mds = session->s_mds;
1417
1418         if (mds >= mdsc->mdsmap->possible_max_rank)
1419                 return;
1420
1421         mi = &mdsc->mdsmap->m_info[mds];
1422         dout("open_export_target_sessions for mds%d (%d targets)\n",
1423              session->s_mds, mi->num_export_targets);
1424
1425         for (i = 0; i < mi->num_export_targets; i++) {
1426                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1427                 if (!IS_ERR(ts))
1428                         ceph_put_mds_session(ts);
1429         }
1430 }
1431
1432 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1433                                            struct ceph_mds_session *session)
1434 {
1435         mutex_lock(&mdsc->mutex);
1436         __open_export_target_sessions(mdsc, session);
1437         mutex_unlock(&mdsc->mutex);
1438 }
1439
1440 /*
1441  * session caps
1442  */
1443
1444 static void detach_cap_releases(struct ceph_mds_session *session,
1445                                 struct list_head *target)
1446 {
1447         lockdep_assert_held(&session->s_cap_lock);
1448
1449         list_splice_init(&session->s_cap_releases, target);
1450         session->s_num_cap_releases = 0;
1451         dout("dispose_cap_releases mds%d\n", session->s_mds);
1452 }
1453
1454 static void dispose_cap_releases(struct ceph_mds_client *mdsc,
1455                                  struct list_head *dispose)
1456 {
1457         while (!list_empty(dispose)) {
1458                 struct ceph_cap *cap;
1459                 /* zero out the in-progress message */
1460                 cap = list_first_entry(dispose, struct ceph_cap, session_caps);
1461                 list_del(&cap->session_caps);
1462                 ceph_put_cap(mdsc, cap);
1463         }
1464 }
1465
1466 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1467                                      struct ceph_mds_session *session)
1468 {
1469         struct ceph_mds_request *req;
1470         struct rb_node *p;
1471         struct ceph_inode_info *ci;
1472
1473         dout("cleanup_session_requests mds%d\n", session->s_mds);
1474         mutex_lock(&mdsc->mutex);
1475         while (!list_empty(&session->s_unsafe)) {
1476                 req = list_first_entry(&session->s_unsafe,
1477                                        struct ceph_mds_request, r_unsafe_item);
1478                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1479                                     req->r_tid);
1480                 if (req->r_target_inode) {
1481                         /* dropping unsafe change of inode's attributes */
1482                         ci = ceph_inode(req->r_target_inode);
1483                         errseq_set(&ci->i_meta_err, -EIO);
1484                 }
1485                 if (req->r_unsafe_dir) {
1486                         /* dropping unsafe directory operation */
1487                         ci = ceph_inode(req->r_unsafe_dir);
1488                         errseq_set(&ci->i_meta_err, -EIO);
1489                 }
1490                 __unregister_request(mdsc, req);
1491         }
1492         /* zero r_attempts, so kick_requests() will re-send requests */
1493         p = rb_first(&mdsc->request_tree);
1494         while (p) {
1495                 req = rb_entry(p, struct ceph_mds_request, r_node);
1496                 p = rb_next(p);
1497                 if (req->r_session &&
1498                     req->r_session->s_mds == session->s_mds)
1499                         req->r_attempts = 0;
1500         }
1501         mutex_unlock(&mdsc->mutex);
1502 }
1503
1504 /*
1505  * Helper to safely iterate over all caps associated with a session, with
1506  * special care taken to handle a racing __ceph_remove_cap().
1507  *
1508  * Caller must hold session s_mutex.
1509  */
1510 int ceph_iterate_session_caps(struct ceph_mds_session *session,
1511                               int (*cb)(struct inode *, struct ceph_cap *,
1512                                         void *), void *arg)
1513 {
1514         struct list_head *p;
1515         struct ceph_cap *cap;
1516         struct inode *inode, *last_inode = NULL;
1517         struct ceph_cap *old_cap = NULL;
1518         int ret;
1519
1520         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1521         spin_lock(&session->s_cap_lock);
1522         p = session->s_caps.next;
1523         while (p != &session->s_caps) {
1524                 cap = list_entry(p, struct ceph_cap, session_caps);
1525                 inode = igrab(&cap->ci->vfs_inode);
1526                 if (!inode) {
1527                         p = p->next;
1528                         continue;
1529                 }
1530                 session->s_cap_iterator = cap;
1531                 spin_unlock(&session->s_cap_lock);
1532
1533                 if (last_inode) {
1534                         /* avoid calling iput_final() while holding
1535                          * s_mutex or in mds dispatch threads */
1536                         ceph_async_iput(last_inode);
1537                         last_inode = NULL;
1538                 }
1539                 if (old_cap) {
1540                         ceph_put_cap(session->s_mdsc, old_cap);
1541                         old_cap = NULL;
1542                 }
1543
1544                 ret = cb(inode, cap, arg);
1545                 last_inode = inode;
1546
1547                 spin_lock(&session->s_cap_lock);
1548                 p = p->next;
1549                 if (!cap->ci) {
1550                         dout("iterate_session_caps  finishing cap %p removal\n",
1551                              cap);
1552                         BUG_ON(cap->session != session);
1553                         cap->session = NULL;
1554                         list_del_init(&cap->session_caps);
1555                         session->s_nr_caps--;
1556                         atomic64_dec(&session->s_mdsc->metric.total_caps);
1557                         if (cap->queue_release)
1558                                 __ceph_queue_cap_release(session, cap);
1559                         else
1560                                 old_cap = cap;  /* put_cap it w/o locks held */
1561                 }
1562                 if (ret < 0)
1563                         goto out;
1564         }
1565         ret = 0;
1566 out:
1567         session->s_cap_iterator = NULL;
1568         spin_unlock(&session->s_cap_lock);
1569
1570         ceph_async_iput(last_inode);
1571         if (old_cap)
1572                 ceph_put_cap(session->s_mdsc, old_cap);
1573
1574         return ret;
1575 }
1576
1577 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1578                                   void *arg)
1579 {
1580         struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1581         struct ceph_inode_info *ci = ceph_inode(inode);
1582         LIST_HEAD(to_remove);
1583         bool dirty_dropped = false;
1584         bool invalidate = false;
1585
1586         dout("removing cap %p, ci is %p, inode is %p\n",
1587              cap, ci, &ci->vfs_inode);
1588         spin_lock(&ci->i_ceph_lock);
1589         __ceph_remove_cap(cap, false);
1590         if (!ci->i_auth_cap) {
1591                 struct ceph_cap_flush *cf;
1592                 struct ceph_mds_client *mdsc = fsc->mdsc;
1593
1594                 if (READ_ONCE(fsc->mount_state) >= CEPH_MOUNT_SHUTDOWN) {
1595                         if (inode->i_data.nrpages > 0)
1596                                 invalidate = true;
1597                         if (ci->i_wrbuffer_ref > 0)
1598                                 mapping_set_error(&inode->i_data, -EIO);
1599                 }
1600
1601                 while (!list_empty(&ci->i_cap_flush_list)) {
1602                         cf = list_first_entry(&ci->i_cap_flush_list,
1603                                               struct ceph_cap_flush, i_list);
1604                         list_move(&cf->i_list, &to_remove);
1605                 }
1606
1607                 spin_lock(&mdsc->cap_dirty_lock);
1608
1609                 list_for_each_entry(cf, &to_remove, i_list)
1610                         list_del(&cf->g_list);
1611
1612                 if (!list_empty(&ci->i_dirty_item)) {
1613                         pr_warn_ratelimited(
1614                                 " dropping dirty %s state for %p %lld\n",
1615                                 ceph_cap_string(ci->i_dirty_caps),
1616                                 inode, ceph_ino(inode));
1617                         ci->i_dirty_caps = 0;
1618                         list_del_init(&ci->i_dirty_item);
1619                         dirty_dropped = true;
1620                 }
1621                 if (!list_empty(&ci->i_flushing_item)) {
1622                         pr_warn_ratelimited(
1623                                 " dropping dirty+flushing %s state for %p %lld\n",
1624                                 ceph_cap_string(ci->i_flushing_caps),
1625                                 inode, ceph_ino(inode));
1626                         ci->i_flushing_caps = 0;
1627                         list_del_init(&ci->i_flushing_item);
1628                         mdsc->num_cap_flushing--;
1629                         dirty_dropped = true;
1630                 }
1631                 spin_unlock(&mdsc->cap_dirty_lock);
1632
1633                 if (dirty_dropped) {
1634                         errseq_set(&ci->i_meta_err, -EIO);
1635
1636                         if (ci->i_wrbuffer_ref_head == 0 &&
1637                             ci->i_wr_ref == 0 &&
1638                             ci->i_dirty_caps == 0 &&
1639                             ci->i_flushing_caps == 0) {
1640                                 ceph_put_snap_context(ci->i_head_snapc);
1641                                 ci->i_head_snapc = NULL;
1642                         }
1643                 }
1644
1645                 if (atomic_read(&ci->i_filelock_ref) > 0) {
1646                         /* make further file lock syscall return -EIO */
1647                         ci->i_ceph_flags |= CEPH_I_ERROR_FILELOCK;
1648                         pr_warn_ratelimited(" dropping file locks for %p %lld\n",
1649                                             inode, ceph_ino(inode));
1650                 }
1651
1652                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1653                         list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
1654                         ci->i_prealloc_cap_flush = NULL;
1655                 }
1656         }
1657         spin_unlock(&ci->i_ceph_lock);
1658         while (!list_empty(&to_remove)) {
1659                 struct ceph_cap_flush *cf;
1660                 cf = list_first_entry(&to_remove,
1661                                       struct ceph_cap_flush, i_list);
1662                 list_del(&cf->i_list);
1663                 ceph_free_cap_flush(cf);
1664         }
1665
1666         wake_up_all(&ci->i_cap_wq);
1667         if (invalidate)
1668                 ceph_queue_invalidate(inode);
1669         if (dirty_dropped)
1670                 iput(inode);
1671         return 0;
1672 }
1673
1674 /*
1675  * caller must hold session s_mutex
1676  */
1677 static void remove_session_caps(struct ceph_mds_session *session)
1678 {
1679         struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1680         struct super_block *sb = fsc->sb;
1681         LIST_HEAD(dispose);
1682
1683         dout("remove_session_caps on %p\n", session);
1684         ceph_iterate_session_caps(session, remove_session_caps_cb, fsc);
1685
1686         wake_up_all(&fsc->mdsc->cap_flushing_wq);
1687
1688         spin_lock(&session->s_cap_lock);
1689         if (session->s_nr_caps > 0) {
1690                 struct inode *inode;
1691                 struct ceph_cap *cap, *prev = NULL;
1692                 struct ceph_vino vino;
1693                 /*
1694                  * iterate_session_caps() skips inodes that are being
1695                  * deleted, we need to wait until deletions are complete.
1696                  * __wait_on_freeing_inode() is designed for the job,
1697                  * but it is not exported, so use lookup inode function
1698                  * to access it.
1699                  */
1700                 while (!list_empty(&session->s_caps)) {
1701                         cap = list_entry(session->s_caps.next,
1702                                          struct ceph_cap, session_caps);
1703                         if (cap == prev)
1704                                 break;
1705                         prev = cap;
1706                         vino = cap->ci->i_vino;
1707                         spin_unlock(&session->s_cap_lock);
1708
1709                         inode = ceph_find_inode(sb, vino);
1710                          /* avoid calling iput_final() while holding s_mutex */
1711                         ceph_async_iput(inode);
1712
1713                         spin_lock(&session->s_cap_lock);
1714                 }
1715         }
1716
1717         // drop cap expires and unlock s_cap_lock
1718         detach_cap_releases(session, &dispose);
1719
1720         BUG_ON(session->s_nr_caps > 0);
1721         BUG_ON(!list_empty(&session->s_cap_flushing));
1722         spin_unlock(&session->s_cap_lock);
1723         dispose_cap_releases(session->s_mdsc, &dispose);
1724 }
1725
1726 enum {
1727         RECONNECT,
1728         RENEWCAPS,
1729         FORCE_RO,
1730 };
1731
1732 /*
1733  * wake up any threads waiting on this session's caps.  if the cap is
1734  * old (didn't get renewed on the client reconnect), remove it now.
1735  *
1736  * caller must hold s_mutex.
1737  */
1738 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1739                               void *arg)
1740 {
1741         struct ceph_inode_info *ci = ceph_inode(inode);
1742         unsigned long ev = (unsigned long)arg;
1743
1744         if (ev == RECONNECT) {
1745                 spin_lock(&ci->i_ceph_lock);
1746                 ci->i_wanted_max_size = 0;
1747                 ci->i_requested_max_size = 0;
1748                 spin_unlock(&ci->i_ceph_lock);
1749         } else if (ev == RENEWCAPS) {
1750                 if (cap->cap_gen < cap->session->s_cap_gen) {
1751                         /* mds did not re-issue stale cap */
1752                         spin_lock(&ci->i_ceph_lock);
1753                         cap->issued = cap->implemented = CEPH_CAP_PIN;
1754                         spin_unlock(&ci->i_ceph_lock);
1755                 }
1756         } else if (ev == FORCE_RO) {
1757         }
1758         wake_up_all(&ci->i_cap_wq);
1759         return 0;
1760 }
1761
1762 static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
1763 {
1764         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1765         ceph_iterate_session_caps(session, wake_up_session_cb,
1766                                   (void *)(unsigned long)ev);
1767 }
1768
1769 /*
1770  * Send periodic message to MDS renewing all currently held caps.  The
1771  * ack will reset the expiration for all caps from this session.
1772  *
1773  * caller holds s_mutex
1774  */
1775 static int send_renew_caps(struct ceph_mds_client *mdsc,
1776                            struct ceph_mds_session *session)
1777 {
1778         struct ceph_msg *msg;
1779         int state;
1780
1781         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1782             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1783                 pr_info("mds%d caps stale\n", session->s_mds);
1784         session->s_renew_requested = jiffies;
1785
1786         /* do not try to renew caps until a recovering mds has reconnected
1787          * with its clients. */
1788         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1789         if (state < CEPH_MDS_STATE_RECONNECT) {
1790                 dout("send_renew_caps ignoring mds%d (%s)\n",
1791                      session->s_mds, ceph_mds_state_name(state));
1792                 return 0;
1793         }
1794
1795         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1796                 ceph_mds_state_name(state));
1797         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1798                                  ++session->s_renew_seq);
1799         if (!msg)
1800                 return -ENOMEM;
1801         ceph_con_send(&session->s_con, msg);
1802         return 0;
1803 }
1804
1805 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1806                              struct ceph_mds_session *session, u64 seq)
1807 {
1808         struct ceph_msg *msg;
1809
1810         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1811              session->s_mds, ceph_session_state_name(session->s_state), seq);
1812         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1813         if (!msg)
1814                 return -ENOMEM;
1815         ceph_con_send(&session->s_con, msg);
1816         return 0;
1817 }
1818
1819
1820 /*
1821  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1822  *
1823  * Called under session->s_mutex
1824  */
1825 static void renewed_caps(struct ceph_mds_client *mdsc,
1826                          struct ceph_mds_session *session, int is_renew)
1827 {
1828         int was_stale;
1829         int wake = 0;
1830
1831         spin_lock(&session->s_cap_lock);
1832         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1833
1834         session->s_cap_ttl = session->s_renew_requested +
1835                 mdsc->mdsmap->m_session_timeout*HZ;
1836
1837         if (was_stale) {
1838                 if (time_before(jiffies, session->s_cap_ttl)) {
1839                         pr_info("mds%d caps renewed\n", session->s_mds);
1840                         wake = 1;
1841                 } else {
1842                         pr_info("mds%d caps still stale\n", session->s_mds);
1843                 }
1844         }
1845         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1846              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1847              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1848         spin_unlock(&session->s_cap_lock);
1849
1850         if (wake)
1851                 wake_up_session_caps(session, RENEWCAPS);
1852 }
1853
1854 /*
1855  * send a session close request
1856  */
1857 static int request_close_session(struct ceph_mds_session *session)
1858 {
1859         struct ceph_msg *msg;
1860
1861         dout("request_close_session mds%d state %s seq %lld\n",
1862              session->s_mds, ceph_session_state_name(session->s_state),
1863              session->s_seq);
1864         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1865         if (!msg)
1866                 return -ENOMEM;
1867         ceph_con_send(&session->s_con, msg);
1868         return 1;
1869 }
1870
1871 /*
1872  * Called with s_mutex held.
1873  */
1874 static int __close_session(struct ceph_mds_client *mdsc,
1875                          struct ceph_mds_session *session)
1876 {
1877         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1878                 return 0;
1879         session->s_state = CEPH_MDS_SESSION_CLOSING;
1880         return request_close_session(session);
1881 }
1882
1883 static bool drop_negative_children(struct dentry *dentry)
1884 {
1885         struct dentry *child;
1886         bool all_negative = true;
1887
1888         if (!d_is_dir(dentry))
1889                 goto out;
1890
1891         spin_lock(&dentry->d_lock);
1892         list_for_each_entry(child, &dentry->d_subdirs, d_child) {
1893                 if (d_really_is_positive(child)) {
1894                         all_negative = false;
1895                         break;
1896                 }
1897         }
1898         spin_unlock(&dentry->d_lock);
1899
1900         if (all_negative)
1901                 shrink_dcache_parent(dentry);
1902 out:
1903         return all_negative;
1904 }
1905
1906 /*
1907  * Trim old(er) caps.
1908  *
1909  * Because we can't cache an inode without one or more caps, we do
1910  * this indirectly: if a cap is unused, we prune its aliases, at which
1911  * point the inode will hopefully get dropped to.
1912  *
1913  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1914  * memory pressure from the MDS, though, so it needn't be perfect.
1915  */
1916 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1917 {
1918         int *remaining = arg;
1919         struct ceph_inode_info *ci = ceph_inode(inode);
1920         int used, wanted, oissued, mine;
1921
1922         if (*remaining <= 0)
1923                 return -1;
1924
1925         spin_lock(&ci->i_ceph_lock);
1926         mine = cap->issued | cap->implemented;
1927         used = __ceph_caps_used(ci);
1928         wanted = __ceph_caps_file_wanted(ci);
1929         oissued = __ceph_caps_issued_other(ci, cap);
1930
1931         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1932              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1933              ceph_cap_string(used), ceph_cap_string(wanted));
1934         if (cap == ci->i_auth_cap) {
1935                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1936                     !list_empty(&ci->i_cap_snaps))
1937                         goto out;
1938                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1939                         goto out;
1940                 /* Note: it's possible that i_filelock_ref becomes non-zero
1941                  * after dropping auth caps. It doesn't hurt because reply
1942                  * of lock mds request will re-add auth caps. */
1943                 if (atomic_read(&ci->i_filelock_ref) > 0)
1944                         goto out;
1945         }
1946         /* The inode has cached pages, but it's no longer used.
1947          * we can safely drop it */
1948         if (S_ISREG(inode->i_mode) &&
1949             wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1950             !(oissued & CEPH_CAP_FILE_CACHE)) {
1951           used = 0;
1952           oissued = 0;
1953         }
1954         if ((used | wanted) & ~oissued & mine)
1955                 goto out;   /* we need these caps */
1956
1957         if (oissued) {
1958                 /* we aren't the only cap.. just remove us */
1959                 __ceph_remove_cap(cap, true);
1960                 (*remaining)--;
1961         } else {
1962                 struct dentry *dentry;
1963                 /* try dropping referring dentries */
1964                 spin_unlock(&ci->i_ceph_lock);
1965                 dentry = d_find_any_alias(inode);
1966                 if (dentry && drop_negative_children(dentry)) {
1967                         int count;
1968                         dput(dentry);
1969                         d_prune_aliases(inode);
1970                         count = atomic_read(&inode->i_count);
1971                         if (count == 1)
1972                                 (*remaining)--;
1973                         dout("trim_caps_cb %p cap %p pruned, count now %d\n",
1974                              inode, cap, count);
1975                 } else {
1976                         dput(dentry);
1977                 }
1978                 return 0;
1979         }
1980
1981 out:
1982         spin_unlock(&ci->i_ceph_lock);
1983         return 0;
1984 }
1985
1986 /*
1987  * Trim session cap count down to some max number.
1988  */
1989 int ceph_trim_caps(struct ceph_mds_client *mdsc,
1990                    struct ceph_mds_session *session,
1991                    int max_caps)
1992 {
1993         int trim_caps = session->s_nr_caps - max_caps;
1994
1995         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1996              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1997         if (trim_caps > 0) {
1998                 int remaining = trim_caps;
1999
2000                 ceph_iterate_session_caps(session, trim_caps_cb, &remaining);
2001                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
2002                      session->s_mds, session->s_nr_caps, max_caps,
2003                         trim_caps - remaining);
2004         }
2005
2006         ceph_flush_cap_releases(mdsc, session);
2007         return 0;
2008 }
2009
2010 static int check_caps_flush(struct ceph_mds_client *mdsc,
2011                             u64 want_flush_tid)
2012 {
2013         int ret = 1;
2014
2015         spin_lock(&mdsc->cap_dirty_lock);
2016         if (!list_empty(&mdsc->cap_flush_list)) {
2017                 struct ceph_cap_flush *cf =
2018                         list_first_entry(&mdsc->cap_flush_list,
2019                                          struct ceph_cap_flush, g_list);
2020                 if (cf->tid <= want_flush_tid) {
2021                         dout("check_caps_flush still flushing tid "
2022                              "%llu <= %llu\n", cf->tid, want_flush_tid);
2023                         ret = 0;
2024                 }
2025         }
2026         spin_unlock(&mdsc->cap_dirty_lock);
2027         return ret;
2028 }
2029
2030 /*
2031  * flush all dirty inode data to disk.
2032  *
2033  * returns true if we've flushed through want_flush_tid
2034  */
2035 static void wait_caps_flush(struct ceph_mds_client *mdsc,
2036                             u64 want_flush_tid)
2037 {
2038         dout("check_caps_flush want %llu\n", want_flush_tid);
2039
2040         wait_event(mdsc->cap_flushing_wq,
2041                    check_caps_flush(mdsc, want_flush_tid));
2042
2043         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
2044 }
2045
2046 /*
2047  * called under s_mutex
2048  */
2049 static void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
2050                                    struct ceph_mds_session *session)
2051 {
2052         struct ceph_msg *msg = NULL;
2053         struct ceph_mds_cap_release *head;
2054         struct ceph_mds_cap_item *item;
2055         struct ceph_osd_client *osdc = &mdsc->fsc->client->osdc;
2056         struct ceph_cap *cap;
2057         LIST_HEAD(tmp_list);
2058         int num_cap_releases;
2059         __le32  barrier, *cap_barrier;
2060
2061         down_read(&osdc->lock);
2062         barrier = cpu_to_le32(osdc->epoch_barrier);
2063         up_read(&osdc->lock);
2064
2065         spin_lock(&session->s_cap_lock);
2066 again:
2067         list_splice_init(&session->s_cap_releases, &tmp_list);
2068         num_cap_releases = session->s_num_cap_releases;
2069         session->s_num_cap_releases = 0;
2070         spin_unlock(&session->s_cap_lock);
2071
2072         while (!list_empty(&tmp_list)) {
2073                 if (!msg) {
2074                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
2075                                         PAGE_SIZE, GFP_NOFS, false);
2076                         if (!msg)
2077                                 goto out_err;
2078                         head = msg->front.iov_base;
2079                         head->num = cpu_to_le32(0);
2080                         msg->front.iov_len = sizeof(*head);
2081
2082                         msg->hdr.version = cpu_to_le16(2);
2083                         msg->hdr.compat_version = cpu_to_le16(1);
2084                 }
2085
2086                 cap = list_first_entry(&tmp_list, struct ceph_cap,
2087                                         session_caps);
2088                 list_del(&cap->session_caps);
2089                 num_cap_releases--;
2090
2091                 head = msg->front.iov_base;
2092                 put_unaligned_le32(get_unaligned_le32(&head->num) + 1,
2093                                    &head->num);
2094                 item = msg->front.iov_base + msg->front.iov_len;
2095                 item->ino = cpu_to_le64(cap->cap_ino);
2096                 item->cap_id = cpu_to_le64(cap->cap_id);
2097                 item->migrate_seq = cpu_to_le32(cap->mseq);
2098                 item->seq = cpu_to_le32(cap->issue_seq);
2099                 msg->front.iov_len += sizeof(*item);
2100
2101                 ceph_put_cap(mdsc, cap);
2102
2103                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
2104                         // Append cap_barrier field
2105                         cap_barrier = msg->front.iov_base + msg->front.iov_len;
2106                         *cap_barrier = barrier;
2107                         msg->front.iov_len += sizeof(*cap_barrier);
2108
2109                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2110                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
2111                         ceph_con_send(&session->s_con, msg);
2112                         msg = NULL;
2113                 }
2114         }
2115
2116         BUG_ON(num_cap_releases != 0);
2117
2118         spin_lock(&session->s_cap_lock);
2119         if (!list_empty(&session->s_cap_releases))
2120                 goto again;
2121         spin_unlock(&session->s_cap_lock);
2122
2123         if (msg) {
2124                 // Append cap_barrier field
2125                 cap_barrier = msg->front.iov_base + msg->front.iov_len;
2126                 *cap_barrier = barrier;
2127                 msg->front.iov_len += sizeof(*cap_barrier);
2128
2129                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2130                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
2131                 ceph_con_send(&session->s_con, msg);
2132         }
2133         return;
2134 out_err:
2135         pr_err("send_cap_releases mds%d, failed to allocate message\n",
2136                 session->s_mds);
2137         spin_lock(&session->s_cap_lock);
2138         list_splice(&tmp_list, &session->s_cap_releases);
2139         session->s_num_cap_releases += num_cap_releases;
2140         spin_unlock(&session->s_cap_lock);
2141 }
2142
2143 static void ceph_cap_release_work(struct work_struct *work)
2144 {
2145         struct ceph_mds_session *session =
2146                 container_of(work, struct ceph_mds_session, s_cap_release_work);
2147
2148         mutex_lock(&session->s_mutex);
2149         if (session->s_state == CEPH_MDS_SESSION_OPEN ||
2150             session->s_state == CEPH_MDS_SESSION_HUNG)
2151                 ceph_send_cap_releases(session->s_mdsc, session);
2152         mutex_unlock(&session->s_mutex);
2153         ceph_put_mds_session(session);
2154 }
2155
2156 void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
2157                              struct ceph_mds_session *session)
2158 {
2159         if (mdsc->stopping)
2160                 return;
2161
2162         ceph_get_mds_session(session);
2163         if (queue_work(mdsc->fsc->cap_wq,
2164                        &session->s_cap_release_work)) {
2165                 dout("cap release work queued\n");
2166         } else {
2167                 ceph_put_mds_session(session);
2168                 dout("failed to queue cap release work\n");
2169         }
2170 }
2171
2172 /*
2173  * caller holds session->s_cap_lock
2174  */
2175 void __ceph_queue_cap_release(struct ceph_mds_session *session,
2176                               struct ceph_cap *cap)
2177 {
2178         list_add_tail(&cap->session_caps, &session->s_cap_releases);
2179         session->s_num_cap_releases++;
2180
2181         if (!(session->s_num_cap_releases % CEPH_CAPS_PER_RELEASE))
2182                 ceph_flush_cap_releases(session->s_mdsc, session);
2183 }
2184
2185 static void ceph_cap_reclaim_work(struct work_struct *work)
2186 {
2187         struct ceph_mds_client *mdsc =
2188                 container_of(work, struct ceph_mds_client, cap_reclaim_work);
2189         int ret = ceph_trim_dentries(mdsc);
2190         if (ret == -EAGAIN)
2191                 ceph_queue_cap_reclaim_work(mdsc);
2192 }
2193
2194 void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc)
2195 {
2196         if (mdsc->stopping)
2197                 return;
2198
2199         if (queue_work(mdsc->fsc->cap_wq, &mdsc->cap_reclaim_work)) {
2200                 dout("caps reclaim work queued\n");
2201         } else {
2202                 dout("failed to queue caps release work\n");
2203         }
2204 }
2205
2206 void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr)
2207 {
2208         int val;
2209         if (!nr)
2210                 return;
2211         val = atomic_add_return(nr, &mdsc->cap_reclaim_pending);
2212         if ((val % CEPH_CAPS_PER_RELEASE) < nr) {
2213                 atomic_set(&mdsc->cap_reclaim_pending, 0);
2214                 ceph_queue_cap_reclaim_work(mdsc);
2215         }
2216 }
2217
2218 /*
2219  * requests
2220  */
2221
2222 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
2223                                     struct inode *dir)
2224 {
2225         struct ceph_inode_info *ci = ceph_inode(dir);
2226         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
2227         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
2228         size_t size = sizeof(struct ceph_mds_reply_dir_entry);
2229         unsigned int num_entries;
2230         int order;
2231
2232         spin_lock(&ci->i_ceph_lock);
2233         num_entries = ci->i_files + ci->i_subdirs;
2234         spin_unlock(&ci->i_ceph_lock);
2235         num_entries = max(num_entries, 1U);
2236         num_entries = min(num_entries, opt->max_readdir);
2237
2238         order = get_order(size * num_entries);
2239         while (order >= 0) {
2240                 rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
2241                                                              __GFP_NOWARN,
2242                                                              order);
2243                 if (rinfo->dir_entries)
2244                         break;
2245                 order--;
2246         }
2247         if (!rinfo->dir_entries)
2248                 return -ENOMEM;
2249
2250         num_entries = (PAGE_SIZE << order) / size;
2251         num_entries = min(num_entries, opt->max_readdir);
2252
2253         rinfo->dir_buf_size = PAGE_SIZE << order;
2254         req->r_num_caps = num_entries + 1;
2255         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
2256         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
2257         return 0;
2258 }
2259
2260 /*
2261  * Create an mds request.
2262  */
2263 struct ceph_mds_request *
2264 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
2265 {
2266         struct ceph_mds_request *req;
2267
2268         req = kmem_cache_zalloc(ceph_mds_request_cachep, GFP_NOFS);
2269         if (!req)
2270                 return ERR_PTR(-ENOMEM);
2271
2272         mutex_init(&req->r_fill_mutex);
2273         req->r_mdsc = mdsc;
2274         req->r_started = jiffies;
2275         req->r_start_latency = ktime_get();
2276         req->r_resend_mds = -1;
2277         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
2278         INIT_LIST_HEAD(&req->r_unsafe_target_item);
2279         req->r_fmode = -1;
2280         kref_init(&req->r_kref);
2281         RB_CLEAR_NODE(&req->r_node);
2282         INIT_LIST_HEAD(&req->r_wait);
2283         init_completion(&req->r_completion);
2284         init_completion(&req->r_safe_completion);
2285         INIT_LIST_HEAD(&req->r_unsafe_item);
2286
2287         ktime_get_coarse_real_ts64(&req->r_stamp);
2288
2289         req->r_op = op;
2290         req->r_direct_mode = mode;
2291         return req;
2292 }
2293
2294 /*
2295  * return oldest (lowest) request, tid in request tree, 0 if none.
2296  *
2297  * called under mdsc->mutex.
2298  */
2299 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
2300 {
2301         if (RB_EMPTY_ROOT(&mdsc->request_tree))
2302                 return NULL;
2303         return rb_entry(rb_first(&mdsc->request_tree),
2304                         struct ceph_mds_request, r_node);
2305 }
2306
2307 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
2308 {
2309         return mdsc->oldest_tid;
2310 }
2311
2312 /*
2313  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
2314  * on build_path_from_dentry in fs/cifs/dir.c.
2315  *
2316  * If @stop_on_nosnap, generate path relative to the first non-snapped
2317  * inode.
2318  *
2319  * Encode hidden .snap dirs as a double /, i.e.
2320  *   foo/.snap/bar -> foo//bar
2321  */
2322 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
2323                            int stop_on_nosnap)
2324 {
2325         struct dentry *temp;
2326         char *path;
2327         int pos;
2328         unsigned seq;
2329         u64 base;
2330
2331         if (!dentry)
2332                 return ERR_PTR(-EINVAL);
2333
2334         path = __getname();
2335         if (!path)
2336                 return ERR_PTR(-ENOMEM);
2337 retry:
2338         pos = PATH_MAX - 1;
2339         path[pos] = '\0';
2340
2341         seq = read_seqbegin(&rename_lock);
2342         rcu_read_lock();
2343         temp = dentry;
2344         for (;;) {
2345                 struct inode *inode;
2346
2347                 spin_lock(&temp->d_lock);
2348                 inode = d_inode(temp);
2349                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
2350                         dout("build_path path+%d: %p SNAPDIR\n",
2351                              pos, temp);
2352                 } else if (stop_on_nosnap && inode && dentry != temp &&
2353                            ceph_snap(inode) == CEPH_NOSNAP) {
2354                         spin_unlock(&temp->d_lock);
2355                         pos++; /* get rid of any prepended '/' */
2356                         break;
2357                 } else {
2358                         pos -= temp->d_name.len;
2359                         if (pos < 0) {
2360                                 spin_unlock(&temp->d_lock);
2361                                 break;
2362                         }
2363                         memcpy(path + pos, temp->d_name.name, temp->d_name.len);
2364                 }
2365                 spin_unlock(&temp->d_lock);
2366                 temp = READ_ONCE(temp->d_parent);
2367
2368                 /* Are we at the root? */
2369                 if (IS_ROOT(temp))
2370                         break;
2371
2372                 /* Are we out of buffer? */
2373                 if (--pos < 0)
2374                         break;
2375
2376                 path[pos] = '/';
2377         }
2378         base = ceph_ino(d_inode(temp));
2379         rcu_read_unlock();
2380
2381         if (read_seqretry(&rename_lock, seq))
2382                 goto retry;
2383
2384         if (pos < 0) {
2385                 /*
2386                  * A rename didn't occur, but somehow we didn't end up where
2387                  * we thought we would. Throw a warning and try again.
2388                  */
2389                 pr_warn("build_path did not end path lookup where "
2390                         "expected, pos is %d\n", pos);
2391                 goto retry;
2392         }
2393
2394         *pbase = base;
2395         *plen = PATH_MAX - 1 - pos;
2396         dout("build_path on %p %d built %llx '%.*s'\n",
2397              dentry, d_count(dentry), base, *plen, path + pos);
2398         return path + pos;
2399 }
2400
2401 static int build_dentry_path(struct dentry *dentry, struct inode *dir,
2402                              const char **ppath, int *ppathlen, u64 *pino,
2403                              bool *pfreepath, bool parent_locked)
2404 {
2405         char *path;
2406
2407         rcu_read_lock();
2408         if (!dir)
2409                 dir = d_inode_rcu(dentry->d_parent);
2410         if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) {
2411                 *pino = ceph_ino(dir);
2412                 rcu_read_unlock();
2413                 *ppath = dentry->d_name.name;
2414                 *ppathlen = dentry->d_name.len;
2415                 return 0;
2416         }
2417         rcu_read_unlock();
2418         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2419         if (IS_ERR(path))
2420                 return PTR_ERR(path);
2421         *ppath = path;
2422         *pfreepath = true;
2423         return 0;
2424 }
2425
2426 static int build_inode_path(struct inode *inode,
2427                             const char **ppath, int *ppathlen, u64 *pino,
2428                             bool *pfreepath)
2429 {
2430         struct dentry *dentry;
2431         char *path;
2432
2433         if (ceph_snap(inode) == CEPH_NOSNAP) {
2434                 *pino = ceph_ino(inode);
2435                 *ppathlen = 0;
2436                 return 0;
2437         }
2438         dentry = d_find_alias(inode);
2439         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2440         dput(dentry);
2441         if (IS_ERR(path))
2442                 return PTR_ERR(path);
2443         *ppath = path;
2444         *pfreepath = true;
2445         return 0;
2446 }
2447
2448 /*
2449  * request arguments may be specified via an inode *, a dentry *, or
2450  * an explicit ino+path.
2451  */
2452 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
2453                                   struct inode *rdiri, const char *rpath,
2454                                   u64 rino, const char **ppath, int *pathlen,
2455                                   u64 *ino, bool *freepath, bool parent_locked)
2456 {
2457         int r = 0;
2458
2459         if (rinode) {
2460                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
2461                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
2462                      ceph_snap(rinode));
2463         } else if (rdentry) {
2464                 r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
2465                                         freepath, parent_locked);
2466                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
2467                      *ppath);
2468         } else if (rpath || rino) {
2469                 *ino = rino;
2470                 *ppath = rpath;
2471                 *pathlen = rpath ? strlen(rpath) : 0;
2472                 dout(" path %.*s\n", *pathlen, rpath);
2473         }
2474
2475         return r;
2476 }
2477
2478 /*
2479  * called under mdsc->mutex
2480  */
2481 static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
2482                                                struct ceph_mds_request *req,
2483                                                bool drop_cap_releases)
2484 {
2485         int mds = session->s_mds;
2486         struct ceph_mds_client *mdsc = session->s_mdsc;
2487         struct ceph_msg *msg;
2488         struct ceph_mds_request_head_old *head;
2489         const char *path1 = NULL;
2490         const char *path2 = NULL;
2491         u64 ino1 = 0, ino2 = 0;
2492         int pathlen1 = 0, pathlen2 = 0;
2493         bool freepath1 = false, freepath2 = false;
2494         int len, i;
2495         u16 releases;
2496         void *p, *end;
2497         int ret;
2498         bool legacy = !(session->s_con.peer_features & CEPH_FEATURE_FS_BTIME);
2499
2500         ret = set_request_path_attr(req->r_inode, req->r_dentry,
2501                               req->r_parent, req->r_path1, req->r_ino1.ino,
2502                               &path1, &pathlen1, &ino1, &freepath1,
2503                               test_bit(CEPH_MDS_R_PARENT_LOCKED,
2504                                         &req->r_req_flags));
2505         if (ret < 0) {
2506                 msg = ERR_PTR(ret);
2507                 goto out;
2508         }
2509
2510         /* If r_old_dentry is set, then assume that its parent is locked */
2511         ret = set_request_path_attr(NULL, req->r_old_dentry,
2512                               req->r_old_dentry_dir,
2513                               req->r_path2, req->r_ino2.ino,
2514                               &path2, &pathlen2, &ino2, &freepath2, true);
2515         if (ret < 0) {
2516                 msg = ERR_PTR(ret);
2517                 goto out_free1;
2518         }
2519
2520         if (legacy) {
2521                 /* Old style */
2522                 len = sizeof(*head);
2523         } else {
2524                 /* New style: add gid_list and any later fields */
2525                 len = sizeof(struct ceph_mds_request_head) + sizeof(u32) +
2526                       (sizeof(u64) * req->r_cred->group_info->ngroups);
2527         }
2528
2529         len += pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
2530                 sizeof(struct ceph_timespec);
2531
2532         /* calculate (max) length for cap releases */
2533         len += sizeof(struct ceph_mds_request_release) *
2534                 (!!req->r_inode_drop + !!req->r_dentry_drop +
2535                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
2536
2537         if (req->r_dentry_drop)
2538                 len += pathlen1;
2539         if (req->r_old_dentry_drop)
2540                 len += pathlen2;
2541
2542         msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
2543         if (!msg) {
2544                 msg = ERR_PTR(-ENOMEM);
2545                 goto out_free2;
2546         }
2547
2548         msg->hdr.tid = cpu_to_le64(req->r_tid);
2549
2550         /*
2551          * The old ceph_mds_request_header didn't contain a version field, and
2552          * one was added when we moved the message version from 3->4.
2553          */
2554         if (legacy) {
2555                 msg->hdr.version = cpu_to_le16(3);
2556                 head = msg->front.iov_base;
2557                 p = msg->front.iov_base + sizeof(*head);
2558         } else {
2559                 struct ceph_mds_request_head *new_head = msg->front.iov_base;
2560
2561                 msg->hdr.version = cpu_to_le16(4);
2562                 new_head->version = cpu_to_le16(CEPH_MDS_REQUEST_HEAD_VERSION);
2563                 head = (struct ceph_mds_request_head_old *)&new_head->oldest_client_tid;
2564                 p = msg->front.iov_base + sizeof(*new_head);
2565         }
2566
2567         end = msg->front.iov_base + msg->front.iov_len;
2568
2569         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
2570         head->op = cpu_to_le32(req->r_op);
2571         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns,
2572                                                  req->r_cred->fsuid));
2573         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns,
2574                                                  req->r_cred->fsgid));
2575         head->ino = cpu_to_le64(req->r_deleg_ino);
2576         head->args = req->r_args;
2577
2578         ceph_encode_filepath(&p, end, ino1, path1);
2579         ceph_encode_filepath(&p, end, ino2, path2);
2580
2581         /* make note of release offset, in case we need to replay */
2582         req->r_request_release_offset = p - msg->front.iov_base;
2583
2584         /* cap releases */
2585         releases = 0;
2586         if (req->r_inode_drop)
2587                 releases += ceph_encode_inode_release(&p,
2588                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
2589                       mds, req->r_inode_drop, req->r_inode_unless,
2590                       req->r_op == CEPH_MDS_OP_READDIR);
2591         if (req->r_dentry_drop)
2592                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
2593                                 req->r_parent, mds, req->r_dentry_drop,
2594                                 req->r_dentry_unless);
2595         if (req->r_old_dentry_drop)
2596                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2597                                 req->r_old_dentry_dir, mds,
2598                                 req->r_old_dentry_drop,
2599                                 req->r_old_dentry_unless);
2600         if (req->r_old_inode_drop)
2601                 releases += ceph_encode_inode_release(&p,
2602                       d_inode(req->r_old_dentry),
2603                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2604
2605         if (drop_cap_releases) {
2606                 releases = 0;
2607                 p = msg->front.iov_base + req->r_request_release_offset;
2608         }
2609
2610         head->num_releases = cpu_to_le16(releases);
2611
2612         /* time stamp */
2613         {
2614                 struct ceph_timespec ts;
2615                 ceph_encode_timespec64(&ts, &req->r_stamp);
2616                 ceph_encode_copy(&p, &ts, sizeof(ts));
2617         }
2618
2619         /* gid list */
2620         if (!legacy) {
2621                 ceph_encode_32(&p, req->r_cred->group_info->ngroups);
2622                 for (i = 0; i < req->r_cred->group_info->ngroups; i++)
2623                         ceph_encode_64(&p, from_kgid(&init_user_ns,
2624                                        req->r_cred->group_info->gid[i]));
2625         }
2626
2627         if (WARN_ON_ONCE(p > end)) {
2628                 ceph_msg_put(msg);
2629                 msg = ERR_PTR(-ERANGE);
2630                 goto out_free2;
2631         }
2632
2633         msg->front.iov_len = p - msg->front.iov_base;
2634         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2635
2636         if (req->r_pagelist) {
2637                 struct ceph_pagelist *pagelist = req->r_pagelist;
2638                 ceph_msg_data_add_pagelist(msg, pagelist);
2639                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2640         } else {
2641                 msg->hdr.data_len = 0;
2642         }
2643
2644         msg->hdr.data_off = cpu_to_le16(0);
2645
2646 out_free2:
2647         if (freepath2)
2648                 ceph_mdsc_free_path((char *)path2, pathlen2);
2649 out_free1:
2650         if (freepath1)
2651                 ceph_mdsc_free_path((char *)path1, pathlen1);
2652 out:
2653         return msg;
2654 }
2655
2656 /*
2657  * called under mdsc->mutex if error, under no mutex if
2658  * success.
2659  */
2660 static void complete_request(struct ceph_mds_client *mdsc,
2661                              struct ceph_mds_request *req)
2662 {
2663         req->r_end_latency = ktime_get();
2664
2665         if (req->r_callback)
2666                 req->r_callback(mdsc, req);
2667         complete_all(&req->r_completion);
2668 }
2669
2670 static struct ceph_mds_request_head_old *
2671 find_old_request_head(void *p, u64 features)
2672 {
2673         bool legacy = !(features & CEPH_FEATURE_FS_BTIME);
2674         struct ceph_mds_request_head *new_head;
2675
2676         if (legacy)
2677                 return (struct ceph_mds_request_head_old *)p;
2678         new_head = (struct ceph_mds_request_head *)p;
2679         return (struct ceph_mds_request_head_old *)&new_head->oldest_client_tid;
2680 }
2681
2682 /*
2683  * called under mdsc->mutex
2684  */
2685 static int __prepare_send_request(struct ceph_mds_session *session,
2686                                   struct ceph_mds_request *req,
2687                                   bool drop_cap_releases)
2688 {
2689         int mds = session->s_mds;
2690         struct ceph_mds_client *mdsc = session->s_mdsc;
2691         struct ceph_mds_request_head_old *rhead;
2692         struct ceph_msg *msg;
2693         int flags = 0;
2694
2695         req->r_attempts++;
2696         if (req->r_inode) {
2697                 struct ceph_cap *cap =
2698                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2699
2700                 if (cap)
2701                         req->r_sent_on_mseq = cap->mseq;
2702                 else
2703                         req->r_sent_on_mseq = -1;
2704         }
2705         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2706              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2707
2708         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2709                 void *p;
2710
2711                 /*
2712                  * Replay.  Do not regenerate message (and rebuild
2713                  * paths, etc.); just use the original message.
2714                  * Rebuilding paths will break for renames because
2715                  * d_move mangles the src name.
2716                  */
2717                 msg = req->r_request;
2718                 rhead = find_old_request_head(msg->front.iov_base,
2719                                               session->s_con.peer_features);
2720
2721                 flags = le32_to_cpu(rhead->flags);
2722                 flags |= CEPH_MDS_FLAG_REPLAY;
2723                 rhead->flags = cpu_to_le32(flags);
2724
2725                 if (req->r_target_inode)
2726                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2727
2728                 rhead->num_retry = req->r_attempts - 1;
2729
2730                 /* remove cap/dentry releases from message */
2731                 rhead->num_releases = 0;
2732
2733                 /* time stamp */
2734                 p = msg->front.iov_base + req->r_request_release_offset;
2735                 {
2736                         struct ceph_timespec ts;
2737                         ceph_encode_timespec64(&ts, &req->r_stamp);
2738                         ceph_encode_copy(&p, &ts, sizeof(ts));
2739                 }
2740
2741                 msg->front.iov_len = p - msg->front.iov_base;
2742                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2743                 return 0;
2744         }
2745
2746         if (req->r_request) {
2747                 ceph_msg_put(req->r_request);
2748                 req->r_request = NULL;
2749         }
2750         msg = create_request_message(session, req, drop_cap_releases);
2751         if (IS_ERR(msg)) {
2752                 req->r_err = PTR_ERR(msg);
2753                 return PTR_ERR(msg);
2754         }
2755         req->r_request = msg;
2756
2757         rhead = find_old_request_head(msg->front.iov_base,
2758                                       session->s_con.peer_features);
2759         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2760         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2761                 flags |= CEPH_MDS_FLAG_REPLAY;
2762         if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags))
2763                 flags |= CEPH_MDS_FLAG_ASYNC;
2764         if (req->r_parent)
2765                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2766         rhead->flags = cpu_to_le32(flags);
2767         rhead->num_fwd = req->r_num_fwd;
2768         rhead->num_retry = req->r_attempts - 1;
2769
2770         dout(" r_parent = %p\n", req->r_parent);
2771         return 0;
2772 }
2773
2774 /*
2775  * called under mdsc->mutex
2776  */
2777 static int __send_request(struct ceph_mds_session *session,
2778                           struct ceph_mds_request *req,
2779                           bool drop_cap_releases)
2780 {
2781         int err;
2782
2783         err = __prepare_send_request(session, req, drop_cap_releases);
2784         if (!err) {
2785                 ceph_msg_get(req->r_request);
2786                 ceph_con_send(&session->s_con, req->r_request);
2787         }
2788
2789         return err;
2790 }
2791
2792 /*
2793  * send request, or put it on the appropriate wait list.
2794  */
2795 static void __do_request(struct ceph_mds_client *mdsc,
2796                         struct ceph_mds_request *req)
2797 {
2798         struct ceph_mds_session *session = NULL;
2799         int mds = -1;
2800         int err = 0;
2801         bool random;
2802
2803         if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2804                 if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2805                         __unregister_request(mdsc, req);
2806                 return;
2807         }
2808
2809         if (req->r_timeout &&
2810             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2811                 dout("do_request timed out\n");
2812                 err = -ETIMEDOUT;
2813                 goto finish;
2814         }
2815         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2816                 dout("do_request forced umount\n");
2817                 err = -EIO;
2818                 goto finish;
2819         }
2820         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2821                 if (mdsc->mdsmap_err) {
2822                         err = mdsc->mdsmap_err;
2823                         dout("do_request mdsmap err %d\n", err);
2824                         goto finish;
2825                 }
2826                 if (mdsc->mdsmap->m_epoch == 0) {
2827                         dout("do_request no mdsmap, waiting for map\n");
2828                         list_add(&req->r_wait, &mdsc->waiting_for_map);
2829                         return;
2830                 }
2831                 if (!(mdsc->fsc->mount_options->flags &
2832                       CEPH_MOUNT_OPT_MOUNTWAIT) &&
2833                     !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2834                         err = -EHOSTUNREACH;
2835                         goto finish;
2836                 }
2837         }
2838
2839         put_request_session(req);
2840
2841         mds = __choose_mds(mdsc, req, &random);
2842         if (mds < 0 ||
2843             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2844                 if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags)) {
2845                         err = -EJUKEBOX;
2846                         goto finish;
2847                 }
2848                 dout("do_request no mds or not active, waiting for map\n");
2849                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2850                 return;
2851         }
2852
2853         /* get, open session */
2854         session = __ceph_lookup_mds_session(mdsc, mds);
2855         if (!session) {
2856                 session = register_session(mdsc, mds);
2857                 if (IS_ERR(session)) {
2858                         err = PTR_ERR(session);
2859                         goto finish;
2860                 }
2861         }
2862         req->r_session = ceph_get_mds_session(session);
2863
2864         dout("do_request mds%d session %p state %s\n", mds, session,
2865              ceph_session_state_name(session->s_state));
2866         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2867             session->s_state != CEPH_MDS_SESSION_HUNG) {
2868                 /*
2869                  * We cannot queue async requests since the caps and delegated
2870                  * inodes are bound to the session. Just return -EJUKEBOX and
2871                  * let the caller retry a sync request in that case.
2872                  */
2873                 if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags)) {
2874                         err = -EJUKEBOX;
2875                         goto out_session;
2876                 }
2877
2878                 /*
2879                  * If the session has been REJECTED, then return a hard error,
2880                  * unless it's a CLEANRECOVER mount, in which case we'll queue
2881                  * it to the mdsc queue.
2882                  */
2883                 if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2884                         if (ceph_test_mount_opt(mdsc->fsc, CLEANRECOVER))
2885                                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2886                         else
2887                                 err = -EACCES;
2888                         goto out_session;
2889                 }
2890
2891                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2892                     session->s_state == CEPH_MDS_SESSION_CLOSING) {
2893                         err = __open_session(mdsc, session);
2894                         if (err)
2895                                 goto out_session;
2896                         /* retry the same mds later */
2897                         if (random)
2898                                 req->r_resend_mds = mds;
2899                 }
2900                 list_add(&req->r_wait, &session->s_waiting);
2901                 goto out_session;
2902         }
2903
2904         /* send request */
2905         req->r_resend_mds = -1;   /* forget any previous mds hint */
2906
2907         if (req->r_request_started == 0)   /* note request start time */
2908                 req->r_request_started = jiffies;
2909
2910         err = __send_request(session, req, false);
2911
2912 out_session:
2913         ceph_put_mds_session(session);
2914 finish:
2915         if (err) {
2916                 dout("__do_request early error %d\n", err);
2917                 req->r_err = err;
2918                 complete_request(mdsc, req);
2919                 __unregister_request(mdsc, req);
2920         }
2921         return;
2922 }
2923
2924 /*
2925  * called under mdsc->mutex
2926  */
2927 static void __wake_requests(struct ceph_mds_client *mdsc,
2928                             struct list_head *head)
2929 {
2930         struct ceph_mds_request *req;
2931         LIST_HEAD(tmp_list);
2932
2933         list_splice_init(head, &tmp_list);
2934
2935         while (!list_empty(&tmp_list)) {
2936                 req = list_entry(tmp_list.next,
2937                                  struct ceph_mds_request, r_wait);
2938                 list_del_init(&req->r_wait);
2939                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2940                 __do_request(mdsc, req);
2941         }
2942 }
2943
2944 /*
2945  * Wake up threads with requests pending for @mds, so that they can
2946  * resubmit their requests to a possibly different mds.
2947  */
2948 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2949 {
2950         struct ceph_mds_request *req;
2951         struct rb_node *p = rb_first(&mdsc->request_tree);
2952
2953         dout("kick_requests mds%d\n", mds);
2954         while (p) {
2955                 req = rb_entry(p, struct ceph_mds_request, r_node);
2956                 p = rb_next(p);
2957                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2958                         continue;
2959                 if (req->r_attempts > 0)
2960                         continue; /* only new requests */
2961                 if (req->r_session &&
2962                     req->r_session->s_mds == mds) {
2963                         dout(" kicking tid %llu\n", req->r_tid);
2964                         list_del_init(&req->r_wait);
2965                         __do_request(mdsc, req);
2966                 }
2967         }
2968 }
2969
2970 int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
2971                               struct ceph_mds_request *req)
2972 {
2973         int err = 0;
2974
2975         /* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
2976         if (req->r_inode)
2977                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2978         if (req->r_parent) {
2979                 struct ceph_inode_info *ci = ceph_inode(req->r_parent);
2980                 int fmode = (req->r_op & CEPH_MDS_OP_WRITE) ?
2981                             CEPH_FILE_MODE_WR : CEPH_FILE_MODE_RD;
2982                 spin_lock(&ci->i_ceph_lock);
2983                 ceph_take_cap_refs(ci, CEPH_CAP_PIN, false);
2984                 __ceph_touch_fmode(ci, mdsc, fmode);
2985                 spin_unlock(&ci->i_ceph_lock);
2986                 ihold(req->r_parent);
2987         }
2988         if (req->r_old_dentry_dir)
2989                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2990                                   CEPH_CAP_PIN);
2991
2992         if (req->r_inode) {
2993                 err = ceph_wait_on_async_create(req->r_inode);
2994                 if (err) {
2995                         dout("%s: wait for async create returned: %d\n",
2996                              __func__, err);
2997                         return err;
2998                 }
2999         }
3000
3001         if (!err && req->r_old_inode) {
3002                 err = ceph_wait_on_async_create(req->r_old_inode);
3003                 if (err) {
3004                         dout("%s: wait for async create returned: %d\n",
3005                              __func__, err);
3006                         return err;
3007                 }
3008         }
3009
3010         dout("submit_request on %p for inode %p\n", req, dir);
3011         mutex_lock(&mdsc->mutex);
3012         __register_request(mdsc, req, dir);
3013         __do_request(mdsc, req);
3014         err = req->r_err;
3015         mutex_unlock(&mdsc->mutex);
3016         return err;
3017 }
3018
3019 static int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
3020                                   struct ceph_mds_request *req)
3021 {
3022         int err;
3023
3024         /* wait */
3025         dout("do_request waiting\n");
3026         if (!req->r_timeout && req->r_wait_for_completion) {
3027                 err = req->r_wait_for_completion(mdsc, req);
3028         } else {
3029                 long timeleft = wait_for_completion_killable_timeout(
3030                                         &req->r_completion,
3031                                         ceph_timeout_jiffies(req->r_timeout));
3032                 if (timeleft > 0)
3033                         err = 0;
3034                 else if (!timeleft)
3035                         err = -ETIMEDOUT;  /* timed out */
3036                 else
3037                         err = timeleft;  /* killed */
3038         }
3039         dout("do_request waited, got %d\n", err);
3040         mutex_lock(&mdsc->mutex);
3041
3042         /* only abort if we didn't race with a real reply */
3043         if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
3044                 err = le32_to_cpu(req->r_reply_info.head->result);
3045         } else if (err < 0) {
3046                 dout("aborted request %lld with %d\n", req->r_tid, err);
3047
3048                 /*
3049                  * ensure we aren't running concurrently with
3050                  * ceph_fill_trace or ceph_readdir_prepopulate, which
3051                  * rely on locks (dir mutex) held by our caller.
3052                  */
3053                 mutex_lock(&req->r_fill_mutex);
3054                 req->r_err = err;
3055                 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
3056                 mutex_unlock(&req->r_fill_mutex);
3057
3058                 if (req->r_parent &&
3059                     (req->r_op & CEPH_MDS_OP_WRITE))
3060                         ceph_invalidate_dir_request(req);
3061         } else {
3062                 err = req->r_err;
3063         }
3064
3065         mutex_unlock(&mdsc->mutex);
3066         return err;
3067 }
3068
3069 /*
3070  * Synchrously perform an mds request.  Take care of all of the
3071  * session setup, forwarding, retry details.
3072  */
3073 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
3074                          struct inode *dir,
3075                          struct ceph_mds_request *req)
3076 {
3077         int err;
3078
3079         dout("do_request on %p\n", req);
3080
3081         /* issue */
3082         err = ceph_mdsc_submit_request(mdsc, dir, req);
3083         if (!err)
3084                 err = ceph_mdsc_wait_request(mdsc, req);
3085         dout("do_request %p done, result %d\n", req, err);
3086         return err;
3087 }
3088
3089 /*
3090  * Invalidate dir's completeness, dentry lease state on an aborted MDS
3091  * namespace request.
3092  */
3093 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
3094 {
3095         struct inode *dir = req->r_parent;
3096         struct inode *old_dir = req->r_old_dentry_dir;
3097
3098         dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
3099
3100         ceph_dir_clear_complete(dir);
3101         if (old_dir)
3102                 ceph_dir_clear_complete(old_dir);
3103         if (req->r_dentry)
3104                 ceph_invalidate_dentry_lease(req->r_dentry);
3105         if (req->r_old_dentry)
3106                 ceph_invalidate_dentry_lease(req->r_old_dentry);
3107 }
3108
3109 /*
3110  * Handle mds reply.
3111  *
3112  * We take the session mutex and parse and process the reply immediately.
3113  * This preserves the logical ordering of replies, capabilities, etc., sent
3114  * by the MDS as they are applied to our local cache.
3115  */
3116 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
3117 {
3118         struct ceph_mds_client *mdsc = session->s_mdsc;
3119         struct ceph_mds_request *req;
3120         struct ceph_mds_reply_head *head = msg->front.iov_base;
3121         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
3122         struct ceph_snap_realm *realm;
3123         u64 tid;
3124         int err, result;
3125         int mds = session->s_mds;
3126
3127         if (msg->front.iov_len < sizeof(*head)) {
3128                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
3129                 ceph_msg_dump(msg);
3130                 return;
3131         }
3132
3133         /* get request, session */
3134         tid = le64_to_cpu(msg->hdr.tid);
3135         mutex_lock(&mdsc->mutex);
3136         req = lookup_get_request(mdsc, tid);
3137         if (!req) {
3138                 dout("handle_reply on unknown tid %llu\n", tid);
3139                 mutex_unlock(&mdsc->mutex);
3140                 return;
3141         }
3142         dout("handle_reply %p\n", req);
3143
3144         /* correct session? */
3145         if (req->r_session != session) {
3146                 pr_err("mdsc_handle_reply got %llu on session mds%d"
3147                        " not mds%d\n", tid, session->s_mds,
3148                        req->r_session ? req->r_session->s_mds : -1);
3149                 mutex_unlock(&mdsc->mutex);
3150                 goto out;
3151         }
3152
3153         /* dup? */
3154         if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
3155             (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
3156                 pr_warn("got a dup %s reply on %llu from mds%d\n",
3157                            head->safe ? "safe" : "unsafe", tid, mds);
3158                 mutex_unlock(&mdsc->mutex);
3159                 goto out;
3160         }
3161         if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
3162                 pr_warn("got unsafe after safe on %llu from mds%d\n",
3163                            tid, mds);
3164                 mutex_unlock(&mdsc->mutex);
3165                 goto out;
3166         }
3167
3168         result = le32_to_cpu(head->result);
3169
3170         /*
3171          * Handle an ESTALE
3172          * if we're not talking to the authority, send to them
3173          * if the authority has changed while we weren't looking,
3174          * send to new authority
3175          * Otherwise we just have to return an ESTALE
3176          */
3177         if (result == -ESTALE) {
3178                 dout("got ESTALE on request %llu\n", req->r_tid);
3179                 req->r_resend_mds = -1;
3180                 if (req->r_direct_mode != USE_AUTH_MDS) {
3181                         dout("not using auth, setting for that now\n");
3182                         req->r_direct_mode = USE_AUTH_MDS;
3183                         __do_request(mdsc, req);
3184                         mutex_unlock(&mdsc->mutex);
3185                         goto out;
3186                 } else  {
3187                         int mds = __choose_mds(mdsc, req, NULL);
3188                         if (mds >= 0 && mds != req->r_session->s_mds) {
3189                                 dout("but auth changed, so resending\n");
3190                                 __do_request(mdsc, req);
3191                                 mutex_unlock(&mdsc->mutex);
3192                                 goto out;
3193                         }
3194                 }
3195                 dout("have to return ESTALE on request %llu\n", req->r_tid);
3196         }
3197
3198
3199         if (head->safe) {
3200                 set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
3201                 __unregister_request(mdsc, req);
3202
3203                 /* last request during umount? */
3204                 if (mdsc->stopping && !__get_oldest_req(mdsc))
3205                         complete_all(&mdsc->safe_umount_waiters);
3206
3207                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
3208                         /*
3209                          * We already handled the unsafe response, now do the
3210                          * cleanup.  No need to examine the response; the MDS
3211                          * doesn't include any result info in the safe
3212                          * response.  And even if it did, there is nothing
3213                          * useful we could do with a revised return value.
3214                          */
3215                         dout("got safe reply %llu, mds%d\n", tid, mds);
3216
3217                         mutex_unlock(&mdsc->mutex);
3218                         goto out;
3219                 }
3220         } else {
3221                 set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
3222                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
3223         }
3224
3225         dout("handle_reply tid %lld result %d\n", tid, result);
3226         rinfo = &req->r_reply_info;
3227         if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
3228                 err = parse_reply_info(session, msg, rinfo, (u64)-1);
3229         else
3230                 err = parse_reply_info(session, msg, rinfo, session->s_con.peer_features);
3231         mutex_unlock(&mdsc->mutex);
3232
3233         /* Must find target inode outside of mutexes to avoid deadlocks */
3234         if ((err >= 0) && rinfo->head->is_target) {
3235                 struct inode *in;
3236                 struct ceph_vino tvino = {
3237                         .ino  = le64_to_cpu(rinfo->targeti.in->ino),
3238                         .snap = le64_to_cpu(rinfo->targeti.in->snapid)
3239                 };
3240
3241                 in = ceph_get_inode(mdsc->fsc->sb, tvino);
3242                 if (IS_ERR(in)) {
3243                         err = PTR_ERR(in);
3244                         mutex_lock(&session->s_mutex);
3245                         goto out_err;
3246                 }
3247                 req->r_target_inode = in;
3248         }
3249
3250         mutex_lock(&session->s_mutex);
3251         if (err < 0) {
3252                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
3253                 ceph_msg_dump(msg);
3254                 goto out_err;
3255         }
3256
3257         /* snap trace */
3258         realm = NULL;
3259         if (rinfo->snapblob_len) {
3260                 down_write(&mdsc->snap_rwsem);
3261                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
3262                                 rinfo->snapblob + rinfo->snapblob_len,
3263                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
3264                                 &realm);
3265                 downgrade_write(&mdsc->snap_rwsem);
3266         } else {
3267                 down_read(&mdsc->snap_rwsem);
3268         }
3269
3270         /* insert trace into our cache */
3271         mutex_lock(&req->r_fill_mutex);
3272         current->journal_info = req;
3273         err = ceph_fill_trace(mdsc->fsc->sb, req);
3274         if (err == 0) {
3275                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
3276                                     req->r_op == CEPH_MDS_OP_LSSNAP))
3277                         ceph_readdir_prepopulate(req, req->r_session);
3278         }
3279         current->journal_info = NULL;
3280         mutex_unlock(&req->r_fill_mutex);
3281
3282         up_read(&mdsc->snap_rwsem);
3283         if (realm)
3284                 ceph_put_snap_realm(mdsc, realm);
3285
3286         if (err == 0) {
3287                 if (req->r_target_inode &&
3288                     test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
3289                         struct ceph_inode_info *ci =
3290                                 ceph_inode(req->r_target_inode);
3291                         spin_lock(&ci->i_unsafe_lock);
3292                         list_add_tail(&req->r_unsafe_target_item,
3293                                       &ci->i_unsafe_iops);
3294                         spin_unlock(&ci->i_unsafe_lock);
3295                 }
3296
3297                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
3298         }
3299 out_err:
3300         mutex_lock(&mdsc->mutex);
3301         if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3302                 if (err) {
3303                         req->r_err = err;
3304                 } else {
3305                         req->r_reply =  ceph_msg_get(msg);
3306                         set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
3307                 }
3308         } else {
3309                 dout("reply arrived after request %lld was aborted\n", tid);
3310         }
3311         mutex_unlock(&mdsc->mutex);
3312
3313         mutex_unlock(&session->s_mutex);
3314
3315         /* kick calling process */
3316         complete_request(mdsc, req);
3317
3318         ceph_update_metadata_latency(&mdsc->metric, req->r_start_latency,
3319                                      req->r_end_latency, err);
3320 out:
3321         ceph_mdsc_put_request(req);
3322         return;
3323 }
3324
3325
3326
3327 /*
3328  * handle mds notification that our request has been forwarded.
3329  */
3330 static void handle_forward(struct ceph_mds_client *mdsc,
3331                            struct ceph_mds_session *session,
3332                            struct ceph_msg *msg)
3333 {
3334         struct ceph_mds_request *req;
3335         u64 tid = le64_to_cpu(msg->hdr.tid);
3336         u32 next_mds;
3337         u32 fwd_seq;
3338         int err = -EINVAL;
3339         void *p = msg->front.iov_base;
3340         void *end = p + msg->front.iov_len;
3341
3342         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
3343         next_mds = ceph_decode_32(&p);
3344         fwd_seq = ceph_decode_32(&p);
3345
3346         mutex_lock(&mdsc->mutex);
3347         req = lookup_get_request(mdsc, tid);
3348         if (!req) {
3349                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
3350                 goto out;  /* dup reply? */
3351         }
3352
3353         if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3354                 dout("forward tid %llu aborted, unregistering\n", tid);
3355                 __unregister_request(mdsc, req);
3356         } else if (fwd_seq <= req->r_num_fwd) {
3357                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
3358                      tid, next_mds, req->r_num_fwd, fwd_seq);
3359         } else {
3360                 /* resend. forward race not possible; mds would drop */
3361                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
3362                 BUG_ON(req->r_err);
3363                 BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
3364                 req->r_attempts = 0;
3365                 req->r_num_fwd = fwd_seq;
3366                 req->r_resend_mds = next_mds;
3367                 put_request_session(req);
3368                 __do_request(mdsc, req);
3369         }
3370         ceph_mdsc_put_request(req);
3371 out:
3372         mutex_unlock(&mdsc->mutex);
3373         return;
3374
3375 bad:
3376         pr_err("mdsc_handle_forward decode error err=%d\n", err);
3377 }
3378
3379 static int __decode_session_metadata(void **p, void *end,
3380                                      bool *blocklisted)
3381 {
3382         /* map<string,string> */
3383         u32 n;
3384         bool err_str;
3385         ceph_decode_32_safe(p, end, n, bad);
3386         while (n-- > 0) {
3387                 u32 len;
3388                 ceph_decode_32_safe(p, end, len, bad);
3389                 ceph_decode_need(p, end, len, bad);
3390                 err_str = !strncmp(*p, "error_string", len);
3391                 *p += len;
3392                 ceph_decode_32_safe(p, end, len, bad);
3393                 ceph_decode_need(p, end, len, bad);
3394                 /*
3395                  * Match "blocklisted (blacklisted)" from newer MDSes,
3396                  * or "blacklisted" from older MDSes.
3397                  */
3398                 if (err_str && strnstr(*p, "blacklisted", len))
3399                         *blocklisted = true;
3400                 *p += len;
3401         }
3402         return 0;
3403 bad:
3404         return -1;
3405 }
3406
3407 /*
3408  * handle a mds session control message
3409  */
3410 static void handle_session(struct ceph_mds_session *session,
3411                            struct ceph_msg *msg)
3412 {
3413         struct ceph_mds_client *mdsc = session->s_mdsc;
3414         int mds = session->s_mds;
3415         int msg_version = le16_to_cpu(msg->hdr.version);
3416         void *p = msg->front.iov_base;
3417         void *end = p + msg->front.iov_len;
3418         struct ceph_mds_session_head *h;
3419         u32 op;
3420         u64 seq, features = 0;
3421         int wake = 0;
3422         bool blocklisted = false;
3423
3424         /* decode */
3425         ceph_decode_need(&p, end, sizeof(*h), bad);
3426         h = p;
3427         p += sizeof(*h);
3428
3429         op = le32_to_cpu(h->op);
3430         seq = le64_to_cpu(h->seq);
3431
3432         if (msg_version >= 3) {
3433                 u32 len;
3434                 /* version >= 2, metadata */
3435                 if (__decode_session_metadata(&p, end, &blocklisted) < 0)
3436                         goto bad;
3437                 /* version >= 3, feature bits */
3438                 ceph_decode_32_safe(&p, end, len, bad);
3439                 if (len) {
3440                         ceph_decode_64_safe(&p, end, features, bad);
3441                         p += len - sizeof(features);
3442                 }
3443         }
3444
3445         mutex_lock(&mdsc->mutex);
3446         if (op == CEPH_SESSION_CLOSE) {
3447                 ceph_get_mds_session(session);
3448                 __unregister_session(mdsc, session);
3449         }
3450         /* FIXME: this ttl calculation is generous */
3451         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
3452         mutex_unlock(&mdsc->mutex);
3453
3454         mutex_lock(&session->s_mutex);
3455
3456         dout("handle_session mds%d %s %p state %s seq %llu\n",
3457              mds, ceph_session_op_name(op), session,
3458              ceph_session_state_name(session->s_state), seq);
3459
3460         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
3461                 session->s_state = CEPH_MDS_SESSION_OPEN;
3462                 pr_info("mds%d came back\n", session->s_mds);
3463         }
3464
3465         switch (op) {
3466         case CEPH_SESSION_OPEN:
3467                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3468                         pr_info("mds%d reconnect success\n", session->s_mds);
3469                 session->s_state = CEPH_MDS_SESSION_OPEN;
3470                 session->s_features = features;
3471                 renewed_caps(mdsc, session, 0);
3472                 if (test_bit(CEPHFS_FEATURE_METRIC_COLLECT, &session->s_features))
3473                         metric_schedule_delayed(&mdsc->metric);
3474                 wake = 1;
3475                 if (mdsc->stopping)
3476                         __close_session(mdsc, session);
3477                 break;
3478
3479         case CEPH_SESSION_RENEWCAPS:
3480                 if (session->s_renew_seq == seq)
3481                         renewed_caps(mdsc, session, 1);
3482                 break;
3483
3484         case CEPH_SESSION_CLOSE:
3485                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3486                         pr_info("mds%d reconnect denied\n", session->s_mds);
3487                 session->s_state = CEPH_MDS_SESSION_CLOSED;
3488                 cleanup_session_requests(mdsc, session);
3489                 remove_session_caps(session);
3490                 wake = 2; /* for good measure */
3491                 wake_up_all(&mdsc->session_close_wq);
3492                 break;
3493
3494         case CEPH_SESSION_STALE:
3495                 pr_info("mds%d caps went stale, renewing\n",
3496                         session->s_mds);
3497                 spin_lock(&session->s_gen_ttl_lock);
3498                 session->s_cap_gen++;
3499                 session->s_cap_ttl = jiffies - 1;
3500                 spin_unlock(&session->s_gen_ttl_lock);
3501                 send_renew_caps(mdsc, session);
3502                 break;
3503
3504         case CEPH_SESSION_RECALL_STATE:
3505                 ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
3506                 break;
3507
3508         case CEPH_SESSION_FLUSHMSG:
3509                 send_flushmsg_ack(mdsc, session, seq);
3510                 break;
3511
3512         case CEPH_SESSION_FORCE_RO:
3513                 dout("force_session_readonly %p\n", session);
3514                 spin_lock(&session->s_cap_lock);
3515                 session->s_readonly = true;
3516                 spin_unlock(&session->s_cap_lock);
3517                 wake_up_session_caps(session, FORCE_RO);
3518                 break;
3519
3520         case CEPH_SESSION_REJECT:
3521                 WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
3522                 pr_info("mds%d rejected session\n", session->s_mds);
3523                 session->s_state = CEPH_MDS_SESSION_REJECTED;
3524                 cleanup_session_requests(mdsc, session);
3525                 remove_session_caps(session);
3526                 if (blocklisted)
3527                         mdsc->fsc->blocklisted = true;
3528                 wake = 2; /* for good measure */
3529                 break;
3530
3531         default:
3532                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
3533                 WARN_ON(1);
3534         }
3535
3536         mutex_unlock(&session->s_mutex);
3537         if (wake) {
3538                 mutex_lock(&mdsc->mutex);
3539                 __wake_requests(mdsc, &session->s_waiting);
3540                 if (wake == 2)
3541                         kick_requests(mdsc, mds);
3542                 mutex_unlock(&mdsc->mutex);
3543         }
3544         if (op == CEPH_SESSION_CLOSE)
3545                 ceph_put_mds_session(session);
3546         return;
3547
3548 bad:
3549         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
3550                (int)msg->front.iov_len);
3551         ceph_msg_dump(msg);
3552         return;
3553 }
3554
3555 void ceph_mdsc_release_dir_caps(struct ceph_mds_request *req)
3556 {
3557         int dcaps;
3558
3559         dcaps = xchg(&req->r_dir_caps, 0);
3560         if (dcaps) {
3561                 dout("releasing r_dir_caps=%s\n", ceph_cap_string(dcaps));
3562                 ceph_put_cap_refs(ceph_inode(req->r_parent), dcaps);
3563         }
3564 }
3565
3566 void ceph_mdsc_release_dir_caps_no_check(struct ceph_mds_request *req)
3567 {
3568         int dcaps;
3569
3570         dcaps = xchg(&req->r_dir_caps, 0);
3571         if (dcaps) {
3572                 dout("releasing r_dir_caps=%s\n", ceph_cap_string(dcaps));
3573                 ceph_put_cap_refs_no_check_caps(ceph_inode(req->r_parent),
3574                                                 dcaps);
3575         }
3576 }
3577
3578 /*
3579  * called under session->mutex.
3580  */
3581 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
3582                                    struct ceph_mds_session *session)
3583 {
3584         struct ceph_mds_request *req, *nreq;
3585         struct rb_node *p;
3586
3587         dout("replay_unsafe_requests mds%d\n", session->s_mds);
3588
3589         mutex_lock(&mdsc->mutex);
3590         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item)
3591                 __send_request(session, req, true);
3592
3593         /*
3594          * also re-send old requests when MDS enters reconnect stage. So that MDS
3595          * can process completed request in clientreplay stage.
3596          */
3597         p = rb_first(&mdsc->request_tree);
3598         while (p) {
3599                 req = rb_entry(p, struct ceph_mds_request, r_node);
3600                 p = rb_next(p);
3601                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3602                         continue;
3603                 if (req->r_attempts == 0)
3604                         continue; /* only old requests */
3605                 if (!req->r_session)
3606                         continue;
3607                 if (req->r_session->s_mds != session->s_mds)
3608                         continue;
3609
3610                 ceph_mdsc_release_dir_caps_no_check(req);
3611
3612                 __send_request(session, req, true);
3613         }
3614         mutex_unlock(&mdsc->mutex);
3615 }
3616
3617 static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
3618 {
3619         struct ceph_msg *reply;
3620         struct ceph_pagelist *_pagelist;
3621         struct page *page;
3622         __le32 *addr;
3623         int err = -ENOMEM;
3624
3625         if (!recon_state->allow_multi)
3626                 return -ENOSPC;
3627
3628         /* can't handle message that contains both caps and realm */
3629         BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3630
3631         /* pre-allocate new pagelist */
3632         _pagelist = ceph_pagelist_alloc(GFP_NOFS);
3633         if (!_pagelist)
3634                 return -ENOMEM;
3635
3636         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3637         if (!reply)
3638                 goto fail_msg;
3639
3640         /* placeholder for nr_caps */
3641         err = ceph_pagelist_encode_32(_pagelist, 0);
3642         if (err < 0)
3643                 goto fail;
3644
3645         if (recon_state->nr_caps) {
3646                 /* currently encoding caps */
3647                 err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3648                 if (err)
3649                         goto fail;
3650         } else {
3651                 /* placeholder for nr_realms (currently encoding relams) */
3652                 err = ceph_pagelist_encode_32(_pagelist, 0);
3653                 if (err < 0)
3654                         goto fail;
3655         }
3656
3657         err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3658         if (err)
3659                 goto fail;
3660
3661         page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3662         addr = kmap_atomic(page);
3663         if (recon_state->nr_caps) {
3664                 /* currently encoding caps */
3665                 *addr = cpu_to_le32(recon_state->nr_caps);
3666         } else {
3667                 /* currently encoding relams */
3668                 *(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3669         }
3670         kunmap_atomic(addr);
3671
3672         reply->hdr.version = cpu_to_le16(5);
3673         reply->hdr.compat_version = cpu_to_le16(4);
3674
3675         reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3676         ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3677
3678         ceph_con_send(&recon_state->session->s_con, reply);
3679         ceph_pagelist_release(recon_state->pagelist);
3680
3681         recon_state->pagelist = _pagelist;
3682         recon_state->nr_caps = 0;
3683         recon_state->nr_realms = 0;
3684         recon_state->msg_version = 5;
3685         return 0;
3686 fail:
3687         ceph_msg_put(reply);
3688 fail_msg:
3689         ceph_pagelist_release(_pagelist);
3690         return err;
3691 }
3692
3693 static struct dentry* d_find_primary(struct inode *inode)
3694 {
3695         struct dentry *alias, *dn = NULL;
3696
3697         if (hlist_empty(&inode->i_dentry))
3698                 return NULL;
3699
3700         spin_lock(&inode->i_lock);
3701         if (hlist_empty(&inode->i_dentry))
3702                 goto out_unlock;
3703
3704         if (S_ISDIR(inode->i_mode)) {
3705                 alias = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
3706                 if (!IS_ROOT(alias))
3707                         dn = dget(alias);
3708                 goto out_unlock;
3709         }
3710
3711         hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
3712                 spin_lock(&alias->d_lock);
3713                 if (!d_unhashed(alias) &&
3714                     (ceph_dentry(alias)->flags & CEPH_DENTRY_PRIMARY_LINK)) {
3715                         dn = dget_dlock(alias);
3716                 }
3717                 spin_unlock(&alias->d_lock);
3718                 if (dn)
3719                         break;
3720         }
3721 out_unlock:
3722         spin_unlock(&inode->i_lock);
3723         return dn;
3724 }
3725
3726 /*
3727  * Encode information about a cap for a reconnect with the MDS.
3728  */
3729 static int reconnect_caps_cb(struct inode *inode, struct ceph_cap *cap,
3730                           void *arg)
3731 {
3732         union {
3733                 struct ceph_mds_cap_reconnect v2;
3734                 struct ceph_mds_cap_reconnect_v1 v1;
3735         } rec;
3736         struct ceph_inode_info *ci = cap->ci;
3737         struct ceph_reconnect_state *recon_state = arg;
3738         struct ceph_pagelist *pagelist = recon_state->pagelist;
3739         struct dentry *dentry;
3740         char *path;
3741         int pathlen, err;
3742         u64 pathbase;
3743         u64 snap_follows;
3744
3745         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3746              inode, ceph_vinop(inode), cap, cap->cap_id,
3747              ceph_cap_string(cap->issued));
3748
3749         dentry = d_find_primary(inode);
3750         if (dentry) {
3751                 /* set pathbase to parent dir when msg_version >= 2 */
3752                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase,
3753                                             recon_state->msg_version >= 2);
3754                 dput(dentry);
3755                 if (IS_ERR(path)) {
3756                         err = PTR_ERR(path);
3757                         goto out_err;
3758                 }
3759         } else {
3760                 path = NULL;
3761                 pathlen = 0;
3762                 pathbase = 0;
3763         }
3764
3765         spin_lock(&ci->i_ceph_lock);
3766         cap->seq = 0;        /* reset cap seq */
3767         cap->issue_seq = 0;  /* and issue_seq */
3768         cap->mseq = 0;       /* and migrate_seq */
3769         cap->cap_gen = cap->session->s_cap_gen;
3770
3771         /* These are lost when the session goes away */
3772         if (S_ISDIR(inode->i_mode)) {
3773                 if (cap->issued & CEPH_CAP_DIR_CREATE) {
3774                         ceph_put_string(rcu_dereference_raw(ci->i_cached_layout.pool_ns));
3775                         memset(&ci->i_cached_layout, 0, sizeof(ci->i_cached_layout));
3776                 }
3777                 cap->issued &= ~CEPH_CAP_ANY_DIR_OPS;
3778         }
3779
3780         if (recon_state->msg_version >= 2) {
3781                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3782                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3783                 rec.v2.issued = cpu_to_le32(cap->issued);
3784                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3785                 rec.v2.pathbase = cpu_to_le64(pathbase);
3786                 rec.v2.flock_len = (__force __le32)
3787                         ((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3788         } else {
3789                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3790                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3791                 rec.v1.issued = cpu_to_le32(cap->issued);
3792                 rec.v1.size = cpu_to_le64(inode->i_size);
3793                 ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3794                 ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3795                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3796                 rec.v1.pathbase = cpu_to_le64(pathbase);
3797         }
3798
3799         if (list_empty(&ci->i_cap_snaps)) {
3800                 snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3801         } else {
3802                 struct ceph_cap_snap *capsnap =
3803                         list_first_entry(&ci->i_cap_snaps,
3804                                          struct ceph_cap_snap, ci_item);
3805                 snap_follows = capsnap->follows;
3806         }
3807         spin_unlock(&ci->i_ceph_lock);
3808
3809         if (recon_state->msg_version >= 2) {
3810                 int num_fcntl_locks, num_flock_locks;
3811                 struct ceph_filelock *flocks = NULL;
3812                 size_t struct_len, total_len = sizeof(u64);
3813                 u8 struct_v = 0;
3814
3815 encode_again:
3816                 if (rec.v2.flock_len) {
3817                         ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
3818                 } else {
3819                         num_fcntl_locks = 0;
3820                         num_flock_locks = 0;
3821                 }
3822                 if (num_fcntl_locks + num_flock_locks > 0) {
3823                         flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
3824                                                sizeof(struct ceph_filelock),
3825                                                GFP_NOFS);
3826                         if (!flocks) {
3827                                 err = -ENOMEM;
3828                                 goto out_err;
3829                         }
3830                         err = ceph_encode_locks_to_buffer(inode, flocks,
3831                                                           num_fcntl_locks,
3832                                                           num_flock_locks);
3833                         if (err) {
3834                                 kfree(flocks);
3835                                 flocks = NULL;
3836                                 if (err == -ENOSPC)
3837                                         goto encode_again;
3838                                 goto out_err;
3839                         }
3840                 } else {
3841                         kfree(flocks);
3842                         flocks = NULL;
3843                 }
3844
3845                 if (recon_state->msg_version >= 3) {
3846                         /* version, compat_version and struct_len */
3847                         total_len += 2 * sizeof(u8) + sizeof(u32);
3848                         struct_v = 2;
3849                 }
3850                 /*
3851                  * number of encoded locks is stable, so copy to pagelist
3852                  */
3853                 struct_len = 2 * sizeof(u32) +
3854                             (num_fcntl_locks + num_flock_locks) *
3855                             sizeof(struct ceph_filelock);
3856                 rec.v2.flock_len = cpu_to_le32(struct_len);
3857
3858                 struct_len += sizeof(u32) + pathlen + sizeof(rec.v2);
3859
3860                 if (struct_v >= 2)
3861                         struct_len += sizeof(u64); /* snap_follows */
3862
3863                 total_len += struct_len;
3864
3865                 if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
3866                         err = send_reconnect_partial(recon_state);
3867                         if (err)
3868                                 goto out_freeflocks;
3869                         pagelist = recon_state->pagelist;
3870                 }
3871
3872                 err = ceph_pagelist_reserve(pagelist, total_len);
3873                 if (err)
3874                         goto out_freeflocks;
3875
3876                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3877                 if (recon_state->msg_version >= 3) {
3878                         ceph_pagelist_encode_8(pagelist, struct_v);
3879                         ceph_pagelist_encode_8(pagelist, 1);
3880                         ceph_pagelist_encode_32(pagelist, struct_len);
3881                 }
3882                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3883                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
3884                 ceph_locks_to_pagelist(flocks, pagelist,
3885                                        num_fcntl_locks, num_flock_locks);
3886                 if (struct_v >= 2)
3887                         ceph_pagelist_encode_64(pagelist, snap_follows);
3888 out_freeflocks:
3889                 kfree(flocks);
3890         } else {
3891                 err = ceph_pagelist_reserve(pagelist,
3892                                             sizeof(u64) + sizeof(u32) +
3893                                             pathlen + sizeof(rec.v1));
3894                 if (err)
3895                         goto out_err;
3896
3897                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3898                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3899                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
3900         }
3901
3902 out_err:
3903         ceph_mdsc_free_path(path, pathlen);
3904         if (!err)
3905                 recon_state->nr_caps++;
3906         return err;
3907 }
3908
3909 static int encode_snap_realms(struct ceph_mds_client *mdsc,
3910                               struct ceph_reconnect_state *recon_state)
3911 {
3912         struct rb_node *p;
3913         struct ceph_pagelist *pagelist = recon_state->pagelist;
3914         int err = 0;
3915
3916         if (recon_state->msg_version >= 4) {
3917                 err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
3918                 if (err < 0)
3919                         goto fail;
3920         }
3921
3922         /*
3923          * snaprealms.  we provide mds with the ino, seq (version), and
3924          * parent for all of our realms.  If the mds has any newer info,
3925          * it will tell us.
3926          */
3927         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3928                 struct ceph_snap_realm *realm =
3929                        rb_entry(p, struct ceph_snap_realm, node);
3930                 struct ceph_mds_snaprealm_reconnect sr_rec;
3931
3932                 if (recon_state->msg_version >= 4) {
3933                         size_t need = sizeof(u8) * 2 + sizeof(u32) +
3934                                       sizeof(sr_rec);
3935
3936                         if (pagelist->length + need > RECONNECT_MAX_SIZE) {
3937                                 err = send_reconnect_partial(recon_state);
3938                                 if (err)
3939                                         goto fail;
3940                                 pagelist = recon_state->pagelist;
3941                         }
3942
3943                         err = ceph_pagelist_reserve(pagelist, need);
3944                         if (err)
3945                                 goto fail;
3946
3947                         ceph_pagelist_encode_8(pagelist, 1);
3948                         ceph_pagelist_encode_8(pagelist, 1);
3949                         ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
3950                 }
3951
3952                 dout(" adding snap realm %llx seq %lld parent %llx\n",
3953                      realm->ino, realm->seq, realm->parent_ino);
3954                 sr_rec.ino = cpu_to_le64(realm->ino);
3955                 sr_rec.seq = cpu_to_le64(realm->seq);
3956                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
3957
3958                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3959                 if (err)
3960                         goto fail;
3961
3962                 recon_state->nr_realms++;
3963         }
3964 fail:
3965         return err;
3966 }
3967
3968
3969 /*
3970  * If an MDS fails and recovers, clients need to reconnect in order to
3971  * reestablish shared state.  This includes all caps issued through
3972  * this session _and_ the snap_realm hierarchy.  Because it's not
3973  * clear which snap realms the mds cares about, we send everything we
3974  * know about.. that ensures we'll then get any new info the
3975  * recovering MDS might have.
3976  *
3977  * This is a relatively heavyweight operation, but it's rare.
3978  */
3979 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
3980                                struct ceph_mds_session *session)
3981 {
3982         struct ceph_msg *reply;
3983         int mds = session->s_mds;
3984         int err = -ENOMEM;
3985         struct ceph_reconnect_state recon_state = {
3986                 .session = session,
3987         };
3988         LIST_HEAD(dispose);
3989
3990         pr_info("mds%d reconnect start\n", mds);
3991
3992         recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
3993         if (!recon_state.pagelist)
3994                 goto fail_nopagelist;
3995
3996         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3997         if (!reply)
3998                 goto fail_nomsg;
3999
4000         xa_destroy(&session->s_delegated_inos);
4001
4002         mutex_lock(&session->s_mutex);
4003         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
4004         session->s_seq = 0;
4005
4006         dout("session %p state %s\n", session,
4007              ceph_session_state_name(session->s_state));
4008
4009         spin_lock(&session->s_gen_ttl_lock);
4010         session->s_cap_gen++;
4011         spin_unlock(&session->s_gen_ttl_lock);
4012
4013         spin_lock(&session->s_cap_lock);
4014         /* don't know if session is readonly */
4015         session->s_readonly = 0;
4016         /*
4017          * notify __ceph_remove_cap() that we are composing cap reconnect.
4018          * If a cap get released before being added to the cap reconnect,
4019          * __ceph_remove_cap() should skip queuing cap release.
4020          */
4021         session->s_cap_reconnect = 1;
4022         /* drop old cap expires; we're about to reestablish that state */
4023         detach_cap_releases(session, &dispose);
4024         spin_unlock(&session->s_cap_lock);
4025         dispose_cap_releases(mdsc, &dispose);
4026
4027         /* trim unused caps to reduce MDS's cache rejoin time */
4028         if (mdsc->fsc->sb->s_root)
4029                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
4030
4031         ceph_con_close(&session->s_con);
4032         ceph_con_open(&session->s_con,
4033                       CEPH_ENTITY_TYPE_MDS, mds,
4034                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
4035
4036         /* replay unsafe requests */
4037         replay_unsafe_requests(mdsc, session);
4038
4039         ceph_early_kick_flushing_caps(mdsc, session);
4040
4041         down_read(&mdsc->snap_rwsem);
4042
4043         /* placeholder for nr_caps */
4044         err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
4045         if (err)
4046                 goto fail;
4047
4048         if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
4049                 recon_state.msg_version = 3;
4050                 recon_state.allow_multi = true;
4051         } else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
4052                 recon_state.msg_version = 3;
4053         } else {
4054                 recon_state.msg_version = 2;
4055         }
4056         /* trsaverse this session's caps */
4057         err = ceph_iterate_session_caps(session, reconnect_caps_cb, &recon_state);
4058
4059         spin_lock(&session->s_cap_lock);
4060         session->s_cap_reconnect = 0;
4061         spin_unlock(&session->s_cap_lock);
4062
4063         if (err < 0)
4064                 goto fail;
4065
4066         /* check if all realms can be encoded into current message */
4067         if (mdsc->num_snap_realms) {
4068                 size_t total_len =
4069                         recon_state.pagelist->length +
4070                         mdsc->num_snap_realms *
4071                         sizeof(struct ceph_mds_snaprealm_reconnect);
4072                 if (recon_state.msg_version >= 4) {
4073                         /* number of realms */
4074                         total_len += sizeof(u32);
4075                         /* version, compat_version and struct_len */
4076                         total_len += mdsc->num_snap_realms *
4077                                      (2 * sizeof(u8) + sizeof(u32));
4078                 }
4079                 if (total_len > RECONNECT_MAX_SIZE) {
4080                         if (!recon_state.allow_multi) {
4081                                 err = -ENOSPC;
4082                                 goto fail;
4083                         }
4084                         if (recon_state.nr_caps) {
4085                                 err = send_reconnect_partial(&recon_state);
4086                                 if (err)
4087                                         goto fail;
4088                         }
4089                         recon_state.msg_version = 5;
4090                 }
4091         }
4092
4093         err = encode_snap_realms(mdsc, &recon_state);
4094         if (err < 0)
4095                 goto fail;
4096
4097         if (recon_state.msg_version >= 5) {
4098                 err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
4099                 if (err < 0)
4100                         goto fail;
4101         }
4102
4103         if (recon_state.nr_caps || recon_state.nr_realms) {
4104                 struct page *page =
4105                         list_first_entry(&recon_state.pagelist->head,
4106                                         struct page, lru);
4107                 __le32 *addr = kmap_atomic(page);
4108                 if (recon_state.nr_caps) {
4109                         WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
4110                         *addr = cpu_to_le32(recon_state.nr_caps);
4111                 } else if (recon_state.msg_version >= 4) {
4112                         *(addr + 1) = cpu_to_le32(recon_state.nr_realms);
4113                 }
4114                 kunmap_atomic(addr);
4115         }
4116
4117         reply->hdr.version = cpu_to_le16(recon_state.msg_version);
4118         if (recon_state.msg_version >= 4)
4119                 reply->hdr.compat_version = cpu_to_le16(4);
4120
4121         reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
4122         ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
4123
4124         ceph_con_send(&session->s_con, reply);
4125
4126         mutex_unlock(&session->s_mutex);
4127
4128         mutex_lock(&mdsc->mutex);
4129         __wake_requests(mdsc, &session->s_waiting);
4130         mutex_unlock(&mdsc->mutex);
4131
4132         up_read(&mdsc->snap_rwsem);
4133         ceph_pagelist_release(recon_state.pagelist);
4134         return;
4135
4136 fail:
4137         ceph_msg_put(reply);
4138         up_read(&mdsc->snap_rwsem);
4139         mutex_unlock(&session->s_mutex);
4140 fail_nomsg:
4141         ceph_pagelist_release(recon_state.pagelist);
4142 fail_nopagelist:
4143         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
4144         return;
4145 }
4146
4147
4148 /*
4149  * compare old and new mdsmaps, kicking requests
4150  * and closing out old connections as necessary
4151  *
4152  * called under mdsc->mutex.
4153  */
4154 static void check_new_map(struct ceph_mds_client *mdsc,
4155                           struct ceph_mdsmap *newmap,
4156                           struct ceph_mdsmap *oldmap)
4157 {
4158         int i;
4159         int oldstate, newstate;
4160         struct ceph_mds_session *s;
4161
4162         dout("check_new_map new %u old %u\n",
4163              newmap->m_epoch, oldmap->m_epoch);
4164
4165         for (i = 0; i < oldmap->possible_max_rank && i < mdsc->max_sessions; i++) {
4166                 if (!mdsc->sessions[i])
4167                         continue;
4168                 s = mdsc->sessions[i];
4169                 oldstate = ceph_mdsmap_get_state(oldmap, i);
4170                 newstate = ceph_mdsmap_get_state(newmap, i);
4171
4172                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
4173                      i, ceph_mds_state_name(oldstate),
4174                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
4175                      ceph_mds_state_name(newstate),
4176                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
4177                      ceph_session_state_name(s->s_state));
4178
4179                 if (i >= newmap->possible_max_rank) {
4180                         /* force close session for stopped mds */
4181                         ceph_get_mds_session(s);
4182                         __unregister_session(mdsc, s);
4183                         __wake_requests(mdsc, &s->s_waiting);
4184                         mutex_unlock(&mdsc->mutex);
4185
4186                         mutex_lock(&s->s_mutex);
4187                         cleanup_session_requests(mdsc, s);
4188                         remove_session_caps(s);
4189                         mutex_unlock(&s->s_mutex);
4190
4191                         ceph_put_mds_session(s);
4192
4193                         mutex_lock(&mdsc->mutex);
4194                         kick_requests(mdsc, i);
4195                         continue;
4196                 }
4197
4198                 if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
4199                            ceph_mdsmap_get_addr(newmap, i),
4200                            sizeof(struct ceph_entity_addr))) {
4201                         /* just close it */
4202                         mutex_unlock(&mdsc->mutex);
4203                         mutex_lock(&s->s_mutex);
4204                         mutex_lock(&mdsc->mutex);
4205                         ceph_con_close(&s->s_con);
4206                         mutex_unlock(&s->s_mutex);
4207                         s->s_state = CEPH_MDS_SESSION_RESTARTING;
4208                 } else if (oldstate == newstate) {
4209                         continue;  /* nothing new with this mds */
4210                 }
4211
4212                 /*
4213                  * send reconnect?
4214                  */
4215                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
4216                     newstate >= CEPH_MDS_STATE_RECONNECT) {
4217                         mutex_unlock(&mdsc->mutex);
4218                         send_mds_reconnect(mdsc, s);
4219                         mutex_lock(&mdsc->mutex);
4220                 }
4221
4222                 /*
4223                  * kick request on any mds that has gone active.
4224                  */
4225                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
4226                     newstate >= CEPH_MDS_STATE_ACTIVE) {
4227                         if (oldstate != CEPH_MDS_STATE_CREATING &&
4228                             oldstate != CEPH_MDS_STATE_STARTING)
4229                                 pr_info("mds%d recovery completed\n", s->s_mds);
4230                         kick_requests(mdsc, i);
4231                         mutex_unlock(&mdsc->mutex);
4232                         mutex_lock(&s->s_mutex);
4233                         mutex_lock(&mdsc->mutex);
4234                         ceph_kick_flushing_caps(mdsc, s);
4235                         mutex_unlock(&s->s_mutex);
4236                         wake_up_session_caps(s, RECONNECT);
4237                 }
4238         }
4239
4240         for (i = 0; i < newmap->possible_max_rank && i < mdsc->max_sessions; i++) {
4241                 s = mdsc->sessions[i];
4242                 if (!s)
4243                         continue;
4244                 if (!ceph_mdsmap_is_laggy(newmap, i))
4245                         continue;
4246                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4247                     s->s_state == CEPH_MDS_SESSION_HUNG ||
4248                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
4249                         dout(" connecting to export targets of laggy mds%d\n",
4250                              i);
4251                         __open_export_target_sessions(mdsc, s);
4252                 }
4253         }
4254 }
4255
4256
4257
4258 /*
4259  * leases
4260  */
4261
4262 /*
4263  * caller must hold session s_mutex, dentry->d_lock
4264  */
4265 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
4266 {
4267         struct ceph_dentry_info *di = ceph_dentry(dentry);
4268
4269         ceph_put_mds_session(di->lease_session);
4270         di->lease_session = NULL;
4271 }
4272
4273 static void handle_lease(struct ceph_mds_client *mdsc,
4274                          struct ceph_mds_session *session,
4275                          struct ceph_msg *msg)
4276 {
4277         struct super_block *sb = mdsc->fsc->sb;
4278         struct inode *inode;
4279         struct dentry *parent, *dentry;
4280         struct ceph_dentry_info *di;
4281         int mds = session->s_mds;
4282         struct ceph_mds_lease *h = msg->front.iov_base;
4283         u32 seq;
4284         struct ceph_vino vino;
4285         struct qstr dname;
4286         int release = 0;
4287
4288         dout("handle_lease from mds%d\n", mds);
4289
4290         /* decode */
4291         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
4292                 goto bad;
4293         vino.ino = le64_to_cpu(h->ino);
4294         vino.snap = CEPH_NOSNAP;
4295         seq = le32_to_cpu(h->seq);
4296         dname.len = get_unaligned_le32(h + 1);
4297         if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
4298                 goto bad;
4299         dname.name = (void *)(h + 1) + sizeof(u32);
4300
4301         /* lookup inode */
4302         inode = ceph_find_inode(sb, vino);
4303         dout("handle_lease %s, ino %llx %p %.*s\n",
4304              ceph_lease_op_name(h->action), vino.ino, inode,
4305              dname.len, dname.name);
4306
4307         mutex_lock(&session->s_mutex);
4308         inc_session_sequence(session);
4309
4310         if (!inode) {
4311                 dout("handle_lease no inode %llx\n", vino.ino);
4312                 goto release;
4313         }
4314
4315         /* dentry */
4316         parent = d_find_alias(inode);
4317         if (!parent) {
4318                 dout("no parent dentry on inode %p\n", inode);
4319                 WARN_ON(1);
4320                 goto release;  /* hrm... */
4321         }
4322         dname.hash = full_name_hash(parent, dname.name, dname.len);
4323         dentry = d_lookup(parent, &dname);
4324         dput(parent);
4325         if (!dentry)
4326                 goto release;
4327
4328         spin_lock(&dentry->d_lock);
4329         di = ceph_dentry(dentry);
4330         switch (h->action) {
4331         case CEPH_MDS_LEASE_REVOKE:
4332                 if (di->lease_session == session) {
4333                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
4334                                 h->seq = cpu_to_le32(di->lease_seq);
4335                         __ceph_mdsc_drop_dentry_lease(dentry);
4336                 }
4337                 release = 1;
4338                 break;
4339
4340         case CEPH_MDS_LEASE_RENEW:
4341                 if (di->lease_session == session &&
4342                     di->lease_gen == session->s_cap_gen &&
4343                     di->lease_renew_from &&
4344                     di->lease_renew_after == 0) {
4345                         unsigned long duration =
4346                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
4347
4348                         di->lease_seq = seq;
4349                         di->time = di->lease_renew_from + duration;
4350                         di->lease_renew_after = di->lease_renew_from +
4351                                 (duration >> 1);
4352                         di->lease_renew_from = 0;
4353                 }
4354                 break;
4355         }
4356         spin_unlock(&dentry->d_lock);
4357         dput(dentry);
4358
4359         if (!release)
4360                 goto out;
4361
4362 release:
4363         /* let's just reuse the same message */
4364         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
4365         ceph_msg_get(msg);
4366         ceph_con_send(&session->s_con, msg);
4367
4368 out:
4369         mutex_unlock(&session->s_mutex);
4370         /* avoid calling iput_final() in mds dispatch threads */
4371         ceph_async_iput(inode);
4372         return;
4373
4374 bad:
4375         pr_err("corrupt lease message\n");
4376         ceph_msg_dump(msg);
4377 }
4378
4379 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
4380                               struct dentry *dentry, char action,
4381                               u32 seq)
4382 {
4383         struct ceph_msg *msg;
4384         struct ceph_mds_lease *lease;
4385         struct inode *dir;
4386         int len = sizeof(*lease) + sizeof(u32) + NAME_MAX;
4387
4388         dout("lease_send_msg identry %p %s to mds%d\n",
4389              dentry, ceph_lease_op_name(action), session->s_mds);
4390
4391         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
4392         if (!msg)
4393                 return;
4394         lease = msg->front.iov_base;
4395         lease->action = action;
4396         lease->seq = cpu_to_le32(seq);
4397
4398         spin_lock(&dentry->d_lock);
4399         dir = d_inode(dentry->d_parent);
4400         lease->ino = cpu_to_le64(ceph_ino(dir));
4401         lease->first = lease->last = cpu_to_le64(ceph_snap(dir));
4402
4403         put_unaligned_le32(dentry->d_name.len, lease + 1);
4404         memcpy((void *)(lease + 1) + 4,
4405                dentry->d_name.name, dentry->d_name.len);
4406         spin_unlock(&dentry->d_lock);
4407         /*
4408          * if this is a preemptive lease RELEASE, no need to
4409          * flush request stream, since the actual request will
4410          * soon follow.
4411          */
4412         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
4413
4414         ceph_con_send(&session->s_con, msg);
4415 }
4416
4417 /*
4418  * lock unlock sessions, to wait ongoing session activities
4419  */
4420 static void lock_unlock_sessions(struct ceph_mds_client *mdsc)
4421 {
4422         int i;
4423
4424         mutex_lock(&mdsc->mutex);
4425         for (i = 0; i < mdsc->max_sessions; i++) {
4426                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4427                 if (!s)
4428                         continue;
4429                 mutex_unlock(&mdsc->mutex);
4430                 mutex_lock(&s->s_mutex);
4431                 mutex_unlock(&s->s_mutex);
4432                 ceph_put_mds_session(s);
4433                 mutex_lock(&mdsc->mutex);
4434         }
4435         mutex_unlock(&mdsc->mutex);
4436 }
4437
4438 static void maybe_recover_session(struct ceph_mds_client *mdsc)
4439 {
4440         struct ceph_fs_client *fsc = mdsc->fsc;
4441
4442         if (!ceph_test_mount_opt(fsc, CLEANRECOVER))
4443                 return;
4444
4445         if (READ_ONCE(fsc->mount_state) != CEPH_MOUNT_MOUNTED)
4446                 return;
4447
4448         if (!READ_ONCE(fsc->blocklisted))
4449                 return;
4450
4451         pr_info("auto reconnect after blocklisted\n");
4452         ceph_force_reconnect(fsc->sb);
4453 }
4454
4455 bool check_session_state(struct ceph_mds_session *s)
4456 {
4457         switch (s->s_state) {
4458         case CEPH_MDS_SESSION_OPEN:
4459                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
4460                         s->s_state = CEPH_MDS_SESSION_HUNG;
4461                         pr_info("mds%d hung\n", s->s_mds);
4462                 }
4463                 break;
4464         case CEPH_MDS_SESSION_CLOSING:
4465                 /* Should never reach this when we're unmounting */
4466                 WARN_ON_ONCE(true);
4467                 fallthrough;
4468         case CEPH_MDS_SESSION_NEW:
4469         case CEPH_MDS_SESSION_RESTARTING:
4470         case CEPH_MDS_SESSION_CLOSED:
4471         case CEPH_MDS_SESSION_REJECTED:
4472                 return false;
4473         }
4474
4475         return true;
4476 }
4477
4478 /*
4479  * If the sequence is incremented while we're waiting on a REQUEST_CLOSE reply,
4480  * then we need to retransmit that request.
4481  */
4482 void inc_session_sequence(struct ceph_mds_session *s)
4483 {
4484         lockdep_assert_held(&s->s_mutex);
4485
4486         s->s_seq++;
4487
4488         if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
4489                 int ret;
4490
4491                 dout("resending session close request for mds%d\n", s->s_mds);
4492                 ret = request_close_session(s);
4493                 if (ret < 0)
4494                         pr_err("unable to close session to mds%d: %d\n",
4495                                s->s_mds, ret);
4496         }
4497 }
4498
4499 /*
4500  * delayed work -- periodically trim expired leases, renew caps with mds
4501  */
4502 static void schedule_delayed(struct ceph_mds_client *mdsc)
4503 {
4504         int delay = 5;
4505         unsigned hz = round_jiffies_relative(HZ * delay);
4506         schedule_delayed_work(&mdsc->delayed_work, hz);
4507 }
4508
4509 static void delayed_work(struct work_struct *work)
4510 {
4511         int i;
4512         struct ceph_mds_client *mdsc =
4513                 container_of(work, struct ceph_mds_client, delayed_work.work);
4514         int renew_interval;
4515         int renew_caps;
4516
4517         dout("mdsc delayed_work\n");
4518
4519         if (mdsc->stopping)
4520                 return;
4521
4522         mutex_lock(&mdsc->mutex);
4523         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
4524         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
4525                                    mdsc->last_renew_caps);
4526         if (renew_caps)
4527                 mdsc->last_renew_caps = jiffies;
4528
4529         for (i = 0; i < mdsc->max_sessions; i++) {
4530                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4531                 if (!s)
4532                         continue;
4533
4534                 if (!check_session_state(s)) {
4535                         ceph_put_mds_session(s);
4536                         continue;
4537                 }
4538                 mutex_unlock(&mdsc->mutex);
4539
4540                 mutex_lock(&s->s_mutex);
4541                 if (renew_caps)
4542                         send_renew_caps(mdsc, s);
4543                 else
4544                         ceph_con_keepalive(&s->s_con);
4545                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4546                     s->s_state == CEPH_MDS_SESSION_HUNG)
4547                         ceph_send_cap_releases(mdsc, s);
4548                 mutex_unlock(&s->s_mutex);
4549                 ceph_put_mds_session(s);
4550
4551                 mutex_lock(&mdsc->mutex);
4552         }
4553         mutex_unlock(&mdsc->mutex);
4554
4555         ceph_check_delayed_caps(mdsc);
4556
4557         ceph_queue_cap_reclaim_work(mdsc);
4558
4559         ceph_trim_snapid_map(mdsc);
4560
4561         maybe_recover_session(mdsc);
4562
4563         schedule_delayed(mdsc);
4564 }
4565
4566 int ceph_mdsc_init(struct ceph_fs_client *fsc)
4567
4568 {
4569         struct ceph_mds_client *mdsc;
4570         int err;
4571
4572         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
4573         if (!mdsc)
4574                 return -ENOMEM;
4575         mdsc->fsc = fsc;
4576         mutex_init(&mdsc->mutex);
4577         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
4578         if (!mdsc->mdsmap) {
4579                 err = -ENOMEM;
4580                 goto err_mdsc;
4581         }
4582
4583         init_completion(&mdsc->safe_umount_waiters);
4584         init_waitqueue_head(&mdsc->session_close_wq);
4585         INIT_LIST_HEAD(&mdsc->waiting_for_map);
4586         mdsc->sessions = NULL;
4587         atomic_set(&mdsc->num_sessions, 0);
4588         mdsc->max_sessions = 0;
4589         mdsc->stopping = 0;
4590         atomic64_set(&mdsc->quotarealms_count, 0);
4591         mdsc->quotarealms_inodes = RB_ROOT;
4592         mutex_init(&mdsc->quotarealms_inodes_mutex);
4593         mdsc->last_snap_seq = 0;
4594         init_rwsem(&mdsc->snap_rwsem);
4595         mdsc->snap_realms = RB_ROOT;
4596         INIT_LIST_HEAD(&mdsc->snap_empty);
4597         mdsc->num_snap_realms = 0;
4598         spin_lock_init(&mdsc->snap_empty_lock);
4599         mdsc->last_tid = 0;
4600         mdsc->oldest_tid = 0;
4601         mdsc->request_tree = RB_ROOT;
4602         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
4603         mdsc->last_renew_caps = jiffies;
4604         INIT_LIST_HEAD(&mdsc->cap_delay_list);
4605         INIT_LIST_HEAD(&mdsc->cap_wait_list);
4606         spin_lock_init(&mdsc->cap_delay_lock);
4607         INIT_LIST_HEAD(&mdsc->snap_flush_list);
4608         spin_lock_init(&mdsc->snap_flush_lock);
4609         mdsc->last_cap_flush_tid = 1;
4610         INIT_LIST_HEAD(&mdsc->cap_flush_list);
4611         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
4612         mdsc->num_cap_flushing = 0;
4613         spin_lock_init(&mdsc->cap_dirty_lock);
4614         init_waitqueue_head(&mdsc->cap_flushing_wq);
4615         INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
4616         atomic_set(&mdsc->cap_reclaim_pending, 0);
4617         err = ceph_metric_init(&mdsc->metric);
4618         if (err)
4619                 goto err_mdsmap;
4620
4621         spin_lock_init(&mdsc->dentry_list_lock);
4622         INIT_LIST_HEAD(&mdsc->dentry_leases);
4623         INIT_LIST_HEAD(&mdsc->dentry_dir_leases);
4624
4625         ceph_caps_init(mdsc);
4626         ceph_adjust_caps_max_min(mdsc, fsc->mount_options);
4627
4628         spin_lock_init(&mdsc->snapid_map_lock);
4629         mdsc->snapid_map_tree = RB_ROOT;
4630         INIT_LIST_HEAD(&mdsc->snapid_map_lru);
4631
4632         init_rwsem(&mdsc->pool_perm_rwsem);
4633         mdsc->pool_perm_tree = RB_ROOT;
4634
4635         strscpy(mdsc->nodename, utsname()->nodename,
4636                 sizeof(mdsc->nodename));
4637
4638         fsc->mdsc = mdsc;
4639         return 0;
4640
4641 err_mdsmap:
4642         kfree(mdsc->mdsmap);
4643 err_mdsc:
4644         kfree(mdsc);
4645         return err;
4646 }
4647
4648 /*
4649  * Wait for safe replies on open mds requests.  If we time out, drop
4650  * all requests from the tree to avoid dangling dentry refs.
4651  */
4652 static void wait_requests(struct ceph_mds_client *mdsc)
4653 {
4654         struct ceph_options *opts = mdsc->fsc->client->options;
4655         struct ceph_mds_request *req;
4656
4657         mutex_lock(&mdsc->mutex);
4658         if (__get_oldest_req(mdsc)) {
4659                 mutex_unlock(&mdsc->mutex);
4660
4661                 dout("wait_requests waiting for requests\n");
4662                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
4663                                     ceph_timeout_jiffies(opts->mount_timeout));
4664
4665                 /* tear down remaining requests */
4666                 mutex_lock(&mdsc->mutex);
4667                 while ((req = __get_oldest_req(mdsc))) {
4668                         dout("wait_requests timed out on tid %llu\n",
4669                              req->r_tid);
4670                         list_del_init(&req->r_wait);
4671                         __unregister_request(mdsc, req);
4672                 }
4673         }
4674         mutex_unlock(&mdsc->mutex);
4675         dout("wait_requests done\n");
4676 }
4677
4678 /*
4679  * called before mount is ro, and before dentries are torn down.
4680  * (hmm, does this still race with new lookups?)
4681  */
4682 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
4683 {
4684         dout("pre_umount\n");
4685         mdsc->stopping = 1;
4686
4687         lock_unlock_sessions(mdsc);
4688         ceph_flush_dirty_caps(mdsc);
4689         wait_requests(mdsc);
4690
4691         /*
4692          * wait for reply handlers to drop their request refs and
4693          * their inode/dcache refs
4694          */
4695         ceph_msgr_flush();
4696
4697         ceph_cleanup_quotarealms_inodes(mdsc);
4698 }
4699
4700 /*
4701  * wait for all write mds requests to flush.
4702  */
4703 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
4704 {
4705         struct ceph_mds_request *req = NULL, *nextreq;
4706         struct rb_node *n;
4707
4708         mutex_lock(&mdsc->mutex);
4709         dout("wait_unsafe_requests want %lld\n", want_tid);
4710 restart:
4711         req = __get_oldest_req(mdsc);
4712         while (req && req->r_tid <= want_tid) {
4713                 /* find next request */
4714                 n = rb_next(&req->r_node);
4715                 if (n)
4716                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
4717                 else
4718                         nextreq = NULL;
4719                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
4720                     (req->r_op & CEPH_MDS_OP_WRITE)) {
4721                         /* write op */
4722                         ceph_mdsc_get_request(req);
4723                         if (nextreq)
4724                                 ceph_mdsc_get_request(nextreq);
4725                         mutex_unlock(&mdsc->mutex);
4726                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
4727                              req->r_tid, want_tid);
4728                         wait_for_completion(&req->r_safe_completion);
4729                         mutex_lock(&mdsc->mutex);
4730                         ceph_mdsc_put_request(req);
4731                         if (!nextreq)
4732                                 break;  /* next dne before, so we're done! */
4733                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
4734                                 /* next request was removed from tree */
4735                                 ceph_mdsc_put_request(nextreq);
4736                                 goto restart;
4737                         }
4738                         ceph_mdsc_put_request(nextreq);  /* won't go away */
4739                 }
4740                 req = nextreq;
4741         }
4742         mutex_unlock(&mdsc->mutex);
4743         dout("wait_unsafe_requests done\n");
4744 }
4745
4746 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
4747 {
4748         u64 want_tid, want_flush;
4749
4750         if (READ_ONCE(mdsc->fsc->mount_state) >= CEPH_MOUNT_SHUTDOWN)
4751                 return;
4752
4753         dout("sync\n");
4754         mutex_lock(&mdsc->mutex);
4755         want_tid = mdsc->last_tid;
4756         mutex_unlock(&mdsc->mutex);
4757
4758         ceph_flush_dirty_caps(mdsc);
4759         spin_lock(&mdsc->cap_dirty_lock);
4760         want_flush = mdsc->last_cap_flush_tid;
4761         if (!list_empty(&mdsc->cap_flush_list)) {
4762                 struct ceph_cap_flush *cf =
4763                         list_last_entry(&mdsc->cap_flush_list,
4764                                         struct ceph_cap_flush, g_list);
4765                 cf->wake = true;
4766         }
4767         spin_unlock(&mdsc->cap_dirty_lock);
4768
4769         dout("sync want tid %lld flush_seq %lld\n",
4770              want_tid, want_flush);
4771
4772         wait_unsafe_requests(mdsc, want_tid);
4773         wait_caps_flush(mdsc, want_flush);
4774 }
4775
4776 /*
4777  * true if all sessions are closed, or we force unmount
4778  */
4779 static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
4780 {
4781         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4782                 return true;
4783         return atomic_read(&mdsc->num_sessions) <= skipped;
4784 }
4785
4786 /*
4787  * called after sb is ro.
4788  */
4789 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
4790 {
4791         struct ceph_options *opts = mdsc->fsc->client->options;
4792         struct ceph_mds_session *session;
4793         int i;
4794         int skipped = 0;
4795
4796         dout("close_sessions\n");
4797
4798         /* close sessions */
4799         mutex_lock(&mdsc->mutex);
4800         for (i = 0; i < mdsc->max_sessions; i++) {
4801                 session = __ceph_lookup_mds_session(mdsc, i);
4802                 if (!session)
4803                         continue;
4804                 mutex_unlock(&mdsc->mutex);
4805                 mutex_lock(&session->s_mutex);
4806                 if (__close_session(mdsc, session) <= 0)
4807                         skipped++;
4808                 mutex_unlock(&session->s_mutex);
4809                 ceph_put_mds_session(session);
4810                 mutex_lock(&mdsc->mutex);
4811         }
4812         mutex_unlock(&mdsc->mutex);
4813
4814         dout("waiting for sessions to close\n");
4815         wait_event_timeout(mdsc->session_close_wq,
4816                            done_closing_sessions(mdsc, skipped),
4817                            ceph_timeout_jiffies(opts->mount_timeout));
4818
4819         /* tear down remaining sessions */
4820         mutex_lock(&mdsc->mutex);
4821         for (i = 0; i < mdsc->max_sessions; i++) {
4822                 if (mdsc->sessions[i]) {
4823                         session = ceph_get_mds_session(mdsc->sessions[i]);
4824                         __unregister_session(mdsc, session);
4825                         mutex_unlock(&mdsc->mutex);
4826                         mutex_lock(&session->s_mutex);
4827                         remove_session_caps(session);
4828                         mutex_unlock(&session->s_mutex);
4829                         ceph_put_mds_session(session);
4830                         mutex_lock(&mdsc->mutex);
4831                 }
4832         }
4833         WARN_ON(!list_empty(&mdsc->cap_delay_list));
4834         mutex_unlock(&mdsc->mutex);
4835
4836         ceph_cleanup_snapid_map(mdsc);
4837         ceph_cleanup_empty_realms(mdsc);
4838
4839         cancel_work_sync(&mdsc->cap_reclaim_work);
4840         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4841
4842         dout("stopped\n");
4843 }
4844
4845 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
4846 {
4847         struct ceph_mds_session *session;
4848         int mds;
4849
4850         dout("force umount\n");
4851
4852         mutex_lock(&mdsc->mutex);
4853         for (mds = 0; mds < mdsc->max_sessions; mds++) {
4854                 session = __ceph_lookup_mds_session(mdsc, mds);
4855                 if (!session)
4856                         continue;
4857
4858                 if (session->s_state == CEPH_MDS_SESSION_REJECTED)
4859                         __unregister_session(mdsc, session);
4860                 __wake_requests(mdsc, &session->s_waiting);
4861                 mutex_unlock(&mdsc->mutex);
4862
4863                 mutex_lock(&session->s_mutex);
4864                 __close_session(mdsc, session);
4865                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
4866                         cleanup_session_requests(mdsc, session);
4867                         remove_session_caps(session);
4868                 }
4869                 mutex_unlock(&session->s_mutex);
4870                 ceph_put_mds_session(session);
4871
4872                 mutex_lock(&mdsc->mutex);
4873                 kick_requests(mdsc, mds);
4874         }
4875         __wake_requests(mdsc, &mdsc->waiting_for_map);
4876         mutex_unlock(&mdsc->mutex);
4877 }
4878
4879 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
4880 {
4881         dout("stop\n");
4882         /*
4883          * Make sure the delayed work stopped before releasing
4884          * the resources.
4885          *
4886          * Because the cancel_delayed_work_sync() will only
4887          * guarantee that the work finishes executing. But the
4888          * delayed work will re-arm itself again after that.
4889          */
4890         flush_delayed_work(&mdsc->delayed_work);
4891
4892         if (mdsc->mdsmap)
4893                 ceph_mdsmap_destroy(mdsc->mdsmap);
4894         kfree(mdsc->sessions);
4895         ceph_caps_finalize(mdsc);
4896         ceph_pool_perm_destroy(mdsc);
4897 }
4898
4899 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
4900 {
4901         struct ceph_mds_client *mdsc = fsc->mdsc;
4902         dout("mdsc_destroy %p\n", mdsc);
4903
4904         if (!mdsc)
4905                 return;
4906
4907         /* flush out any connection work with references to us */
4908         ceph_msgr_flush();
4909
4910         ceph_mdsc_stop(mdsc);
4911
4912         ceph_metric_destroy(&mdsc->metric);
4913
4914         flush_delayed_work(&mdsc->metric.delayed_work);
4915         fsc->mdsc = NULL;
4916         kfree(mdsc);
4917         dout("mdsc_destroy %p done\n", mdsc);
4918 }
4919
4920 void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4921 {
4922         struct ceph_fs_client *fsc = mdsc->fsc;
4923         const char *mds_namespace = fsc->mount_options->mds_namespace;
4924         void *p = msg->front.iov_base;
4925         void *end = p + msg->front.iov_len;
4926         u32 epoch;
4927         u32 num_fs;
4928         u32 mount_fscid = (u32)-1;
4929         int err = -EINVAL;
4930
4931         ceph_decode_need(&p, end, sizeof(u32), bad);
4932         epoch = ceph_decode_32(&p);
4933
4934         dout("handle_fsmap epoch %u\n", epoch);
4935
4936         /* struct_v, struct_cv, map_len, epoch, legacy_client_fscid */
4937         ceph_decode_skip_n(&p, end, 2 + sizeof(u32) * 3, bad);
4938
4939         ceph_decode_32_safe(&p, end, num_fs, bad);
4940         while (num_fs-- > 0) {
4941                 void *info_p, *info_end;
4942                 u32 info_len;
4943                 u32 fscid, namelen;
4944
4945                 ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4946                 p += 2;         // info_v, info_cv
4947                 info_len = ceph_decode_32(&p);
4948                 ceph_decode_need(&p, end, info_len, bad);
4949                 info_p = p;
4950                 info_end = p + info_len;
4951                 p = info_end;
4952
4953                 ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
4954                 fscid = ceph_decode_32(&info_p);
4955                 namelen = ceph_decode_32(&info_p);
4956                 ceph_decode_need(&info_p, info_end, namelen, bad);
4957
4958                 if (mds_namespace &&
4959                     strlen(mds_namespace) == namelen &&
4960                     !strncmp(mds_namespace, (char *)info_p, namelen)) {
4961                         mount_fscid = fscid;
4962                         break;
4963                 }
4964         }
4965
4966         ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
4967         if (mount_fscid != (u32)-1) {
4968                 fsc->client->monc.fs_cluster_id = mount_fscid;
4969                 ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
4970                                    0, true);
4971                 ceph_monc_renew_subs(&fsc->client->monc);
4972         } else {
4973                 err = -ENOENT;
4974                 goto err_out;
4975         }
4976         return;
4977
4978 bad:
4979         pr_err("error decoding fsmap\n");
4980 err_out:
4981         mutex_lock(&mdsc->mutex);
4982         mdsc->mdsmap_err = err;
4983         __wake_requests(mdsc, &mdsc->waiting_for_map);
4984         mutex_unlock(&mdsc->mutex);
4985 }
4986
4987 /*
4988  * handle mds map update.
4989  */
4990 void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4991 {
4992         u32 epoch;
4993         u32 maplen;
4994         void *p = msg->front.iov_base;
4995         void *end = p + msg->front.iov_len;
4996         struct ceph_mdsmap *newmap, *oldmap;
4997         struct ceph_fsid fsid;
4998         int err = -EINVAL;
4999
5000         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
5001         ceph_decode_copy(&p, &fsid, sizeof(fsid));
5002         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
5003                 return;
5004         epoch = ceph_decode_32(&p);
5005         maplen = ceph_decode_32(&p);
5006         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
5007
5008         /* do we need it? */
5009         mutex_lock(&mdsc->mutex);
5010         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
5011                 dout("handle_map epoch %u <= our %u\n",
5012                      epoch, mdsc->mdsmap->m_epoch);
5013                 mutex_unlock(&mdsc->mutex);
5014                 return;
5015         }
5016
5017         newmap = ceph_mdsmap_decode(&p, end, ceph_msgr2(mdsc->fsc->client));
5018         if (IS_ERR(newmap)) {
5019                 err = PTR_ERR(newmap);
5020                 goto bad_unlock;
5021         }
5022
5023         /* swap into place */
5024         if (mdsc->mdsmap) {
5025                 oldmap = mdsc->mdsmap;
5026                 mdsc->mdsmap = newmap;
5027                 check_new_map(mdsc, newmap, oldmap);
5028                 ceph_mdsmap_destroy(oldmap);
5029         } else {
5030                 mdsc->mdsmap = newmap;  /* first mds map */
5031         }
5032         mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
5033                                         MAX_LFS_FILESIZE);
5034
5035         __wake_requests(mdsc, &mdsc->waiting_for_map);
5036         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
5037                           mdsc->mdsmap->m_epoch);
5038
5039         mutex_unlock(&mdsc->mutex);
5040         schedule_delayed(mdsc);
5041         return;
5042
5043 bad_unlock:
5044         mutex_unlock(&mdsc->mutex);
5045 bad:
5046         pr_err("error decoding mdsmap %d\n", err);
5047         return;
5048 }
5049
5050 static struct ceph_connection *con_get(struct ceph_connection *con)
5051 {
5052         struct ceph_mds_session *s = con->private;
5053
5054         if (ceph_get_mds_session(s))
5055                 return con;
5056         return NULL;
5057 }
5058
5059 static void con_put(struct ceph_connection *con)
5060 {
5061         struct ceph_mds_session *s = con->private;
5062
5063         ceph_put_mds_session(s);
5064 }
5065
5066 /*
5067  * if the client is unresponsive for long enough, the mds will kill
5068  * the session entirely.
5069  */
5070 static void peer_reset(struct ceph_connection *con)
5071 {
5072         struct ceph_mds_session *s = con->private;
5073         struct ceph_mds_client *mdsc = s->s_mdsc;
5074
5075         pr_warn("mds%d closed our session\n", s->s_mds);
5076         send_mds_reconnect(mdsc, s);
5077 }
5078
5079 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
5080 {
5081         struct ceph_mds_session *s = con->private;
5082         struct ceph_mds_client *mdsc = s->s_mdsc;
5083         int type = le16_to_cpu(msg->hdr.type);
5084
5085         mutex_lock(&mdsc->mutex);
5086         if (__verify_registered_session(mdsc, s) < 0) {
5087                 mutex_unlock(&mdsc->mutex);
5088                 goto out;
5089         }
5090         mutex_unlock(&mdsc->mutex);
5091
5092         switch (type) {
5093         case CEPH_MSG_MDS_MAP:
5094                 ceph_mdsc_handle_mdsmap(mdsc, msg);
5095                 break;
5096         case CEPH_MSG_FS_MAP_USER:
5097                 ceph_mdsc_handle_fsmap(mdsc, msg);
5098                 break;
5099         case CEPH_MSG_CLIENT_SESSION:
5100                 handle_session(s, msg);
5101                 break;
5102         case CEPH_MSG_CLIENT_REPLY:
5103                 handle_reply(s, msg);
5104                 break;
5105         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
5106                 handle_forward(mdsc, s, msg);
5107                 break;
5108         case CEPH_MSG_CLIENT_CAPS:
5109                 ceph_handle_caps(s, msg);
5110                 break;
5111         case CEPH_MSG_CLIENT_SNAP:
5112                 ceph_handle_snap(mdsc, s, msg);
5113                 break;
5114         case CEPH_MSG_CLIENT_LEASE:
5115                 handle_lease(mdsc, s, msg);
5116                 break;
5117         case CEPH_MSG_CLIENT_QUOTA:
5118                 ceph_handle_quota(mdsc, s, msg);
5119                 break;
5120
5121         default:
5122                 pr_err("received unknown message type %d %s\n", type,
5123                        ceph_msg_type_name(type));
5124         }
5125 out:
5126         ceph_msg_put(msg);
5127 }
5128
5129 /*
5130  * authentication
5131  */
5132
5133 /*
5134  * Note: returned pointer is the address of a structure that's
5135  * managed separately.  Caller must *not* attempt to free it.
5136  */
5137 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
5138                                         int *proto, int force_new)
5139 {
5140         struct ceph_mds_session *s = con->private;
5141         struct ceph_mds_client *mdsc = s->s_mdsc;
5142         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5143         struct ceph_auth_handshake *auth = &s->s_auth;
5144
5145         if (force_new && auth->authorizer) {
5146                 ceph_auth_destroy_authorizer(auth->authorizer);
5147                 auth->authorizer = NULL;
5148         }
5149         if (!auth->authorizer) {
5150                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
5151                                                       auth);
5152                 if (ret)
5153                         return ERR_PTR(ret);
5154         } else {
5155                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
5156                                                       auth);
5157                 if (ret)
5158                         return ERR_PTR(ret);
5159         }
5160         *proto = ac->protocol;
5161
5162         return auth;
5163 }
5164
5165 static int add_authorizer_challenge(struct ceph_connection *con,
5166                                     void *challenge_buf, int challenge_buf_len)
5167 {
5168         struct ceph_mds_session *s = con->private;
5169         struct ceph_mds_client *mdsc = s->s_mdsc;
5170         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5171
5172         return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
5173                                             challenge_buf, challenge_buf_len);
5174 }
5175
5176 static int verify_authorizer_reply(struct ceph_connection *con)
5177 {
5178         struct ceph_mds_session *s = con->private;
5179         struct ceph_mds_client *mdsc = s->s_mdsc;
5180         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5181         struct ceph_auth_handshake *auth = &s->s_auth;
5182
5183         return ceph_auth_verify_authorizer_reply(ac, auth->authorizer,
5184                 auth->authorizer_reply_buf, auth->authorizer_reply_buf_len,
5185                 NULL, NULL, NULL, NULL);
5186 }
5187
5188 static int invalidate_authorizer(struct ceph_connection *con)
5189 {
5190         struct ceph_mds_session *s = con->private;
5191         struct ceph_mds_client *mdsc = s->s_mdsc;
5192         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5193
5194         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
5195
5196         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
5197 }
5198
5199 static int mds_get_auth_request(struct ceph_connection *con,
5200                                 void *buf, int *buf_len,
5201                                 void **authorizer, int *authorizer_len)
5202 {
5203         struct ceph_mds_session *s = con->private;
5204         struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5205         struct ceph_auth_handshake *auth = &s->s_auth;
5206         int ret;
5207
5208         ret = ceph_auth_get_authorizer(ac, auth, CEPH_ENTITY_TYPE_MDS,
5209                                        buf, buf_len);
5210         if (ret)
5211                 return ret;
5212
5213         *authorizer = auth->authorizer_buf;
5214         *authorizer_len = auth->authorizer_buf_len;
5215         return 0;
5216 }
5217
5218 static int mds_handle_auth_reply_more(struct ceph_connection *con,
5219                                       void *reply, int reply_len,
5220                                       void *buf, int *buf_len,
5221                                       void **authorizer, int *authorizer_len)
5222 {
5223         struct ceph_mds_session *s = con->private;
5224         struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5225         struct ceph_auth_handshake *auth = &s->s_auth;
5226         int ret;
5227
5228         ret = ceph_auth_handle_svc_reply_more(ac, auth, reply, reply_len,
5229                                               buf, buf_len);
5230         if (ret)
5231                 return ret;
5232
5233         *authorizer = auth->authorizer_buf;
5234         *authorizer_len = auth->authorizer_buf_len;
5235         return 0;
5236 }
5237
5238 static int mds_handle_auth_done(struct ceph_connection *con,
5239                                 u64 global_id, void *reply, int reply_len,
5240                                 u8 *session_key, int *session_key_len,
5241                                 u8 *con_secret, int *con_secret_len)
5242 {
5243         struct ceph_mds_session *s = con->private;
5244         struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5245         struct ceph_auth_handshake *auth = &s->s_auth;
5246
5247         return ceph_auth_handle_svc_reply_done(ac, auth, reply, reply_len,
5248                                                session_key, session_key_len,
5249                                                con_secret, con_secret_len);
5250 }
5251
5252 static int mds_handle_auth_bad_method(struct ceph_connection *con,
5253                                       int used_proto, int result,
5254                                       const int *allowed_protos, int proto_cnt,
5255                                       const int *allowed_modes, int mode_cnt)
5256 {
5257         struct ceph_mds_session *s = con->private;
5258         struct ceph_mon_client *monc = &s->s_mdsc->fsc->client->monc;
5259         int ret;
5260
5261         if (ceph_auth_handle_bad_authorizer(monc->auth, CEPH_ENTITY_TYPE_MDS,
5262                                             used_proto, result,
5263                                             allowed_protos, proto_cnt,
5264                                             allowed_modes, mode_cnt)) {
5265                 ret = ceph_monc_validate_auth(monc);
5266                 if (ret)
5267                         return ret;
5268         }
5269
5270         return -EACCES;
5271 }
5272
5273 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
5274                                 struct ceph_msg_header *hdr, int *skip)
5275 {
5276         struct ceph_msg *msg;
5277         int type = (int) le16_to_cpu(hdr->type);
5278         int front_len = (int) le32_to_cpu(hdr->front_len);
5279
5280         if (con->in_msg)
5281                 return con->in_msg;
5282
5283         *skip = 0;
5284         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
5285         if (!msg) {
5286                 pr_err("unable to allocate msg type %d len %d\n",
5287                        type, front_len);
5288                 return NULL;
5289         }
5290
5291         return msg;
5292 }
5293
5294 static int mds_sign_message(struct ceph_msg *msg)
5295 {
5296        struct ceph_mds_session *s = msg->con->private;
5297        struct ceph_auth_handshake *auth = &s->s_auth;
5298
5299        return ceph_auth_sign_message(auth, msg);
5300 }
5301
5302 static int mds_check_message_signature(struct ceph_msg *msg)
5303 {
5304        struct ceph_mds_session *s = msg->con->private;
5305        struct ceph_auth_handshake *auth = &s->s_auth;
5306
5307        return ceph_auth_check_message_signature(auth, msg);
5308 }
5309
5310 static const struct ceph_connection_operations mds_con_ops = {
5311         .get = con_get,
5312         .put = con_put,
5313         .dispatch = dispatch,
5314         .get_authorizer = get_authorizer,
5315         .add_authorizer_challenge = add_authorizer_challenge,
5316         .verify_authorizer_reply = verify_authorizer_reply,
5317         .invalidate_authorizer = invalidate_authorizer,
5318         .peer_reset = peer_reset,
5319         .alloc_msg = mds_alloc_msg,
5320         .sign_message = mds_sign_message,
5321         .check_message_signature = mds_check_message_signature,
5322         .get_auth_request = mds_get_auth_request,
5323         .handle_auth_reply_more = mds_handle_auth_reply_more,
5324         .handle_auth_done = mds_handle_auth_done,
5325         .handle_auth_bad_method = mds_handle_auth_bad_method,
5326 };
5327
5328 /* eof */