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  49  * are no longer valid.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                         u8 struct_v, struct_compat;
 520                         u32 len;
 521
 522                         info->has_create_ino = true;
 523                         ceph_decode_8_safe(p, end, struct_v, bad);
 524                         ceph_decode_8_safe(p, end, struct_compat, bad);
 525                         ceph_decode_32_safe(p, end, len, bad);
 526                         ceph_decode_64_safe(p, end, info->ino, bad);
 527                         ret = ceph_parse_deleg_inos(p, end, s);
 528                         if (ret)
 529                                 return ret;
 530                 } else {
 531                         /* legacy */
 532                         ceph_decode_64_safe(p, end, info->ino, bad);
 533                         info->has_create_ino = true;
 534                 }
 535         } else {
 536                 if (*p != end)
 537                         goto bad;
 538         }
 539
 540         /* Skip over any unrecognized fields */
 541         *p = end;
 542         return 0;
 543 bad:
 544         return -EIO;
 545 }
 546
 547 /*
 548  * parse extra results
 549  */
 550 static int parse_reply_info_extra(void **p, void *end,
 551                                   struct ceph_mds_reply_info_parsed *info,
 552                                   u64 features, struct ceph_mds_session *s)
 553 {
 554         u32 op = le32_to_cpu(info->head->op);
 555
 556         if (op == CEPH_MDS_OP_GETFILELOCK)
 557                 return parse_reply_info_filelock(p, end, info, features);
 558         else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 559                 return parse_reply_info_readdir(p, end, info, features);
 560         else if (op == CEPH_MDS_OP_CREATE)
 561                 return parse_reply_info_create(p, end, info, features, s);
 562         else
 563                 return -EIO;
 564 }
 565
 566 /*
 567  * parse entire mds reply
 568  */
 569 static int parse_reply_info(struct ceph_mds_session *s, struct ceph_msg *msg,
 570                             struct ceph_mds_reply_info_parsed *info,
 571                             u64 features)
 572 {
 573         void *p, *end;
 574         u32 len;
 575         int err;
 576
 577         info->head = msg->front.iov_base;
 578         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 579         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 580
 581         /* trace */
 582         ceph_decode_32_safe(&p, end, len, bad);
 583         if (len > 0) {
 584                 ceph_decode_need(&p, end, len, bad);
 585                 err = parse_reply_info_trace(&p, p+len, info, features);
 586                 if (err < 0)
 587                         goto out_bad;
 588         }
 589
 590         /* extra */
 591         ceph_decode_32_safe(&p, end, len, bad);
 592         if (len > 0) {
 593                 ceph_decode_need(&p, end, len, bad);
 594                 err = parse_reply_info_extra(&p, p+len, info, features, s);
 595                 if (err < 0)
 596                         goto out_bad;
 597         }
 598
 599         /* snap blob */
 600         ceph_decode_32_safe(&p, end, len, bad);
 601         info->snapblob_len = len;
 602         info->snapblob = p;
 603         p += len;
 604
 605         if (p != end)
 606                 goto bad;
 607         return 0;
 608
 609 bad:
 610         err = -EIO;
 611 out_bad:
 612         pr_err("mds parse_reply err %d\n", err);
 613         return err;
 614 }
 615
 616 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 617 {
 618         if (!info->dir_entries)
 619                 return;
 620         free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 621 }
 622
 623
 624 /*
 625  * sessions
 626  */
 627 const char *ceph_session_state_name(int s)
 628 {
 629         switch (s) {
 630         case CEPH_MDS_SESSION_NEW: return "new";
 631         case CEPH_MDS_SESSION_OPENING: return "opening";
 632         case CEPH_MDS_SESSION_OPEN: return "open";
 633         case CEPH_MDS_SESSION_HUNG: return "hung";
 634         case CEPH_MDS_SESSION_CLOSING: return "closing";
 635         case CEPH_MDS_SESSION_CLOSED: return "closed";
 636         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 637         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 638         case CEPH_MDS_SESSION_REJECTED: return "rejected";
 639         default: return "???";
 640         }
 641 }
 642
 643 struct ceph_mds_session *ceph_get_mds_session(struct ceph_mds_session *s)
 644 {
 645         if (refcount_inc_not_zero(&s->s_ref)) {
 646                 dout("mdsc get_session %p %d -> %d\n", s,
 647                      refcount_read(&s->s_ref)-1, refcount_read(&s->s_ref));
 648                 return s;
 649         } else {
 650                 dout("mdsc get_session %p 0 -- FAIL\n", s);
 651                 return NULL;
 652         }
 653 }
 654
 655 void ceph_put_mds_session(struct ceph_mds_session *s)
 656 {
 657         dout("mdsc put_session %p %d -> %d\n", s,
 658              refcount_read(&s->s_ref), refcount_read(&s->s_ref)-1);
 659         if (refcount_dec_and_test(&s->s_ref)) {
 660                 if (s->s_auth.authorizer)
 661                         ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 662                 WARN_ON(mutex_is_locked(&s->s_mutex));
 663                 xa_destroy(&s->s_delegated_inos);
 664                 kfree(s);
 665         }
 666 }
 667
 668 /*
 669  * called under mdsc->mutex
 670  */
 671 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 672                                                    int mds)
 673 {
 674         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 675                 return NULL;
 676         return ceph_get_mds_session(mdsc->sessions[mds]);
 677 }
 678
 679 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 680 {
 681         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 682                 return false;
 683         else
 684                 return true;
 685 }
 686
 687 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 688                                        struct ceph_mds_session *s)
 689 {
 690         if (s->s_mds >= mdsc->max_sessions ||
 691             mdsc->sessions[s->s_mds] != s)
 692                 return -ENOENT;
 693         return 0;
 694 }
 695
 696 /*
 697  * create+register a new session for given mds.
 698  * called under mdsc->mutex.
 699  */
 700 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 701                                                  int mds)
 702 {
 703         struct ceph_mds_session *s;
 704
 705         if (mds >= mdsc->mdsmap->possible_max_rank)
 706                 return ERR_PTR(-EINVAL);
 707
 708         s = kzalloc(sizeof(*s), GFP_NOFS);
 709         if (!s)
 710                 return ERR_PTR(-ENOMEM);
 711
 712         if (mds >= mdsc->max_sessions) {
 713                 int newmax = 1 << get_count_order(mds + 1);
 714                 struct ceph_mds_session **sa;
 715
 716                 dout("%s: realloc to %d\n", __func__, newmax);
 717                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 718                 if (!sa)
 719                         goto fail_realloc;
 720                 if (mdsc->sessions) {
 721                         memcpy(sa, mdsc->sessions,
 722                                mdsc->max_sessions * sizeof(void *));
 723                         kfree(mdsc->sessions);
 724                 }
 725                 mdsc->sessions = sa;
 726                 mdsc->max_sessions = newmax;
 727         }
 728
 729         dout("%s: mds%d\n", __func__, mds);
 730         s->s_mdsc = mdsc;
 731         s->s_mds = mds;
 732         s->s_state = CEPH_MDS_SESSION_NEW;
 733         s->s_ttl = 0;
 734         s->s_seq = 0;
 735         mutex_init(&s->s_mutex);
 736
 737         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 738
 739         spin_lock_init(&s->s_gen_ttl_lock);
 740         s->s_cap_gen = 1;
 741         s->s_cap_ttl = jiffies - 1;
 742
 743         spin_lock_init(&s->s_cap_lock);
 744         s->s_renew_requested = 0;
 745         s->s_renew_seq = 0;
 746         INIT_LIST_HEAD(&s->s_caps);
 747         s->s_nr_caps = 0;
 748         refcount_set(&s->s_ref, 1);
 749         INIT_LIST_HEAD(&s->s_waiting);
 750         INIT_LIST_HEAD(&s->s_unsafe);
 751         xa_init(&s->s_delegated_inos);
 752         s->s_num_cap_releases = 0;
 753         s->s_cap_reconnect = 0;
 754         s->s_cap_iterator = NULL;
 755         INIT_LIST_HEAD(&s->s_cap_releases);
 756         INIT_WORK(&s->s_cap_release_work, ceph_cap_release_work);
 757
 758         INIT_LIST_HEAD(&s->s_cap_dirty);
 759         INIT_LIST_HEAD(&s->s_cap_flushing);
 760
 761         mdsc->sessions[mds] = s;
 762         atomic_inc(&mdsc->num_sessions);
 763         refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 764
 765         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 766                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 767
 768         return s;
 769
 770 fail_realloc:
 771         kfree(s);
 772         return ERR_PTR(-ENOMEM);
 773 }
 774
 775 /*
 776  * called under mdsc->mutex
 777  */
 778 static void __unregister_session(struct ceph_mds_client *mdsc,
 779                                struct ceph_mds_session *s)
 780 {
 781         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 782         BUG_ON(mdsc->sessions[s->s_mds] != s);
 783         mdsc->sessions[s->s_mds] = NULL;
 784         ceph_con_close(&s->s_con);
 785         ceph_put_mds_session(s);
 786         atomic_dec(&mdsc->num_sessions);
 787 }
 788
 789 /*
 790  * drop session refs in request.
 791  *
 792  * should be last request ref, or hold mdsc->mutex
 793  */
 794 static void put_request_session(struct ceph_mds_request *req)
 795 {
 796         if (req->r_session) {
 797                 ceph_put_mds_session(req->r_session);
 798                 req->r_session = NULL;
 799         }
 800 }
 801
 802 void ceph_mdsc_release_request(struct kref *kref)
 803 {
 804         struct ceph_mds_request *req = container_of(kref,
 805                                                     struct ceph_mds_request,
 806                                                     r_kref);
 807         ceph_mdsc_release_dir_caps_no_check(req);
 808         destroy_reply_info(&req->r_reply_info);
 809         if (req->r_request)
 810                 ceph_msg_put(req->r_request);
 811         if (req->r_reply)
 812                 ceph_msg_put(req->r_reply);
 813         if (req->r_inode) {
 814                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 815                 /* avoid calling iput_final() in mds dispatch threads */
 816                 ceph_async_iput(req->r_inode);
 817         }
 818         if (req->r_parent) {
 819                 ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
 820                 ceph_async_iput(req->r_parent);
 821         }
 822         ceph_async_iput(req->r_target_inode);
 823         if (req->r_dentry)
 824                 dput(req->r_dentry);
 825         if (req->r_old_dentry)
 826                 dput(req->r_old_dentry);
 827         if (req->r_old_dentry_dir) {
 828                 /*
 829                  * track (and drop pins for) r_old_dentry_dir
 830                  * separately, since r_old_dentry's d_parent may have
 831                  * changed between the dir mutex being dropped and
 832                  * this request being freed.
 833                  */
 834                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 835                                   CEPH_CAP_PIN);
 836                 ceph_async_iput(req->r_old_dentry_dir);
 837         }
 838         kfree(req->r_path1);
 839         kfree(req->r_path2);
 840         if (req->r_pagelist)
 841                 ceph_pagelist_release(req->r_pagelist);
 842         put_request_session(req);
 843         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 844         WARN_ON_ONCE(!list_empty(&req->r_wait));
 845         kmem_cache_free(ceph_mds_request_cachep, req);
 846 }
 847
 848 DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 849
 850 /*
 851  * lookup session, bump ref if found.
 852  *
 853  * called under mdsc->mutex.
 854  */
 855 static struct ceph_mds_request *
 856 lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 857 {
 858         struct ceph_mds_request *req;
 859
 860         req = lookup_request(&mdsc->request_tree, tid);
 861         if (req)
 862                 ceph_mdsc_get_request(req);
 863
 864         return req;
 865 }
 866
 867 /*
 868  * Register an in-flight request, and assign a tid.  Link to directory
 869  * are modifying (if any).
 870  *
 871  * Called under mdsc->mutex.
 872  */
 873 static void __register_request(struct ceph_mds_client *mdsc,
 874                                struct ceph_mds_request *req,
 875                                struct inode *dir)
 876 {
 877         int ret = 0;
 878
 879         req->r_tid = ++mdsc->last_tid;
 880         if (req->r_num_caps) {
 881                 ret = ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 882                                         req->r_num_caps);
 883                 if (ret < 0) {
 884                         pr_err("__register_request %p "
 885                                "failed to reserve caps: %d\n", req, ret);
 886                         /* set req->r_err to fail early from __do_request */
 887                         req->r_err = ret;
 888                         return;
 889                 }
 890         }
 891         dout("__register_request %p tid %lld\n", req, req->r_tid);
 892         ceph_mdsc_get_request(req);
 893         insert_request(&mdsc->request_tree, req);
 894
 895         req->r_uid = current_fsuid();
 896         req->r_gid = current_fsgid();
 897
 898         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 899                 mdsc->oldest_tid = req->r_tid;
 900
 901         if (dir) {
 902                 struct ceph_inode_info *ci = ceph_inode(dir);
 903
 904                 ihold(dir);
 905                 req->r_unsafe_dir = dir;
 906                 spin_lock(&ci->i_unsafe_lock);
 907                 list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 908                 spin_unlock(&ci->i_unsafe_lock);
 909         }
 910 }
 911
 912 static void __unregister_request(struct ceph_mds_client *mdsc,
 913                                  struct ceph_mds_request *req)
 914 {
 915         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 916
 917         /* Never leave an unregistered request on an unsafe list! */
 918         list_del_init(&req->r_unsafe_item);
 919
 920         if (req->r_tid == mdsc->oldest_tid) {
 921                 struct rb_node *p = rb_next(&req->r_node);
 922                 mdsc->oldest_tid = 0;
 923                 while (p) {
 924                         struct ceph_mds_request *next_req =
 925                                 rb_entry(p, struct ceph_mds_request, r_node);
 926                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 927                                 mdsc->oldest_tid = next_req->r_tid;
 928                                 break;
 929                         }
 930                         p = rb_next(p);
 931                 }
 932         }
 933
 934         erase_request(&mdsc->request_tree, req);
 935
 936         if (req->r_unsafe_dir) {
 937                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 938                 spin_lock(&ci->i_unsafe_lock);
 939                 list_del_init(&req->r_unsafe_dir_item);
 940                 spin_unlock(&ci->i_unsafe_lock);
 941         }
 942         if (req->r_target_inode &&
 943             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 944                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 945                 spin_lock(&ci->i_unsafe_lock);
 946                 list_del_init(&req->r_unsafe_target_item);
 947                 spin_unlock(&ci->i_unsafe_lock);
 948         }
 949
 950         if (req->r_unsafe_dir) {
 951                 /* avoid calling iput_final() in mds dispatch threads */
 952                 ceph_async_iput(req->r_unsafe_dir);
 953                 req->r_unsafe_dir = NULL;
 954         }
 955
 956         complete_all(&req->r_safe_completion);
 957
 958         ceph_mdsc_put_request(req);
 959 }
 960
 961 /*
 962  * Walk back up the dentry tree until we hit a dentry representing a
 963  * non-snapshot inode. We do this using the rcu_read_lock (which must be held
 964  * when calling this) to ensure that the objects won't disappear while we're
 965  * working with them. Once we hit a candidate dentry, we attempt to take a
 966  * reference to it, and return that as the result.
 967  */
 968 static struct inode *get_nonsnap_parent(struct dentry *dentry)
 969 {
 970         struct inode *inode = NULL;
 971
 972         while (dentry && !IS_ROOT(dentry)) {
 973                 inode = d_inode_rcu(dentry);
 974                 if (!inode || ceph_snap(inode) == CEPH_NOSNAP)
 975                         break;
 976                 dentry = dentry->d_parent;
 977         }
 978         if (inode)
 979                 inode = igrab(inode);
 980         return inode;
 981 }
 982
 983 /*
 984  * Choose mds to send request to next.  If there is a hint set in the
 985  * request (e.g., due to a prior forward hint from the mds), use that.
 986  * Otherwise, consult frag tree and/or caps to identify the
 987  * appropriate mds.  If all else fails, choose randomly.
 988  *
 989  * Called under mdsc->mutex.
 990  */
 991 static int __choose_mds(struct ceph_mds_client *mdsc,
 992                         struct ceph_mds_request *req,
 993                         bool *random)
 994 {
 995         struct inode *inode;
 996         struct ceph_inode_info *ci;
 997         struct ceph_cap *cap;
 998         int mode = req->r_direct_mode;
 999         int mds = -1;
1000         u32 hash = req->r_direct_hash;
1001         bool is_hash = test_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
1002
1003         if (random)
1004                 *random = false;
1005
1006         /*
1007          * is there a specific mds we should try?  ignore hint if we have
1008          * no session and the mds is not up (active or recovering).
1009          */
1010         if (req->r_resend_mds >= 0 &&
1011             (__have_session(mdsc, req->r_resend_mds) ||
1012              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
1013                 dout("%s using resend_mds mds%d\n", __func__,
1014                      req->r_resend_mds);
1015                 return req->r_resend_mds;
1016         }
1017
1018         if (mode == USE_RANDOM_MDS)
1019                 goto random;
1020
1021         inode = NULL;
1022         if (req->r_inode) {
1023                 if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
1024                         inode = req->r_inode;
1025                         ihold(inode);
1026                 } else {
1027                         /* req->r_dentry is non-null for LSSNAP request */
1028                         rcu_read_lock();
1029                         inode = get_nonsnap_parent(req->r_dentry);
1030                         rcu_read_unlock();
1031                         dout("%s using snapdir's parent %p\n", __func__, inode);
1032                 }
1033         } else if (req->r_dentry) {
1034                 /* ignore race with rename; old or new d_parent is okay */
1035                 struct dentry *parent;
1036                 struct inode *dir;
1037
1038                 rcu_read_lock();
1039                 parent = READ_ONCE(req->r_dentry->d_parent);
1040                 dir = req->r_parent ? : d_inode_rcu(parent);
1041
1042                 if (!dir || dir->i_sb != mdsc->fsc->sb) {
1043                         /*  not this fs or parent went negative */
1044                         inode = d_inode(req->r_dentry);
1045                         if (inode)
1046                                 ihold(inode);
1047                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
1048                         /* direct snapped/virtual snapdir requests
1049                          * based on parent dir inode */
1050                         inode = get_nonsnap_parent(parent);
1051                         dout("%s using nonsnap parent %p\n", __func__, inode);
1052                 } else {
1053                         /* dentry target */
1054                         inode = d_inode(req->r_dentry);
1055                         if (!inode || mode == USE_AUTH_MDS) {
1056                                 /* dir + name */
1057                                 inode = igrab(dir);
1058                                 hash = ceph_dentry_hash(dir, req->r_dentry);
1059                                 is_hash = true;
1060                         } else {
1061                                 ihold(inode);
1062                         }
1063                 }
1064                 rcu_read_unlock();
1065         }
1066
1067         dout("%s %p is_hash=%d (0x%x) mode %d\n", __func__, inode, (int)is_hash,
1068              hash, mode);
1069         if (!inode)
1070                 goto random;
1071         ci = ceph_inode(inode);
1072
1073         if (is_hash && S_ISDIR(inode->i_mode)) {
1074                 struct ceph_inode_frag frag;
1075                 int found;
1076
1077                 ceph_choose_frag(ci, hash, &frag, &found);
1078                 if (found) {
1079                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
1080                                 u8 r;
1081
1082                                 /* choose a random replica */
1083                                 get_random_bytes(&r, 1);
1084                                 r %= frag.ndist;
1085                                 mds = frag.dist[r];
1086                                 dout("%s %p %llx.%llx frag %u mds%d (%d/%d)\n",
1087                                      __func__, inode, ceph_vinop(inode),
1088                                      frag.frag, mds, (int)r, frag.ndist);
1089                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
1090                                     CEPH_MDS_STATE_ACTIVE &&
1091                                     !ceph_mdsmap_is_laggy(mdsc->mdsmap, mds))
1092                                         goto out;
1093                         }
1094
1095                         /* since this file/dir wasn't known to be
1096                          * replicated, then we want to look for the
1097                          * authoritative mds. */
1098                         if (frag.mds >= 0) {
1099                                 /* choose auth mds */
1100                                 mds = frag.mds;
1101                                 dout("%s %p %llx.%llx frag %u mds%d (auth)\n",
1102                                      __func__, inode, ceph_vinop(inode),
1103                                      frag.frag, mds);
1104                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
1105                                     CEPH_MDS_STATE_ACTIVE) {
1106                                         if (!ceph_mdsmap_is_laggy(mdsc->mdsmap,
1107                                                                   mds))
1108                                                 goto out;
1109                                 }
1110                         }
1111                         mode = USE_AUTH_MDS;
1112                 }
1113         }
1114
1115         spin_lock(&ci->i_ceph_lock);
1116         cap = NULL;
1117         if (mode == USE_AUTH_MDS)
1118                 cap = ci->i_auth_cap;
1119         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
1120                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
1121         if (!cap) {
1122                 spin_unlock(&ci->i_ceph_lock);
1123                 ceph_async_iput(inode);
1124                 goto random;
1125         }
1126         mds = cap->session->s_mds;
1127         dout("%s %p %llx.%llx mds%d (%scap %p)\n", __func__,
1128              inode, ceph_vinop(inode), mds,
1129              cap == ci->i_auth_cap ? "auth " : "", cap);
1130         spin_unlock(&ci->i_ceph_lock);
1131 out:
1132         /* avoid calling iput_final() while holding mdsc->mutex or
1133          * in mds dispatch threads */
1134         ceph_async_iput(inode);
1135         return mds;
1136
1137 random:
1138         if (random)
1139                 *random = true;
1140
1141         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
1142         dout("%s chose random mds%d\n", __func__, mds);
1143         return mds;
1144 }
1145
1146
1147 /*
1148  * session messages
1149  */
1150 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
1151 {
1152         struct ceph_msg *msg;
1153         struct ceph_mds_session_head *h;
1154
1155         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
1156                            false);
1157         if (!msg) {
1158                 pr_err("create_session_msg ENOMEM creating msg\n");
1159                 return NULL;
1160         }
1161         h = msg->front.iov_base;
1162         h->op = cpu_to_le32(op);
1163         h->seq = cpu_to_le64(seq);
1164
1165         return msg;
1166 }
1167
1168 static const unsigned char feature_bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
1169 #define FEATURE_BYTES(c) (DIV_ROUND_UP((size_t)feature_bits[c - 1] + 1, 64) * 8)
1170 static int encode_supported_features(void **p, void *end)
1171 {
1172         static const size_t count = ARRAY_SIZE(feature_bits);
1173
1174         if (count > 0) {
1175                 size_t i;
1176                 size_t size = FEATURE_BYTES(count);
1177
1178                 if (WARN_ON_ONCE(*p + 4 + size > end))
1179                         return -ERANGE;
1180
1181                 ceph_encode_32(p, size);
1182                 memset(*p, 0, size);
1183                 for (i = 0; i < count; i++)
1184                         ((unsigned char*)(*p))[i / 8] |= BIT(feature_bits[i] % 8);
1185                 *p += size;
1186         } else {
1187                 if (WARN_ON_ONCE(*p + 4 > end))
1188                         return -ERANGE;
1189
1190                 ceph_encode_32(p, 0);
1191         }
1192
1193         return 0;
1194 }
1195
1196 static const unsigned char metric_bits[] = CEPHFS_METRIC_SPEC_CLIENT_SUPPORTED;
1197 #define METRIC_BYTES(cnt) (DIV_ROUND_UP((size_t)metric_bits[cnt - 1] + 1, 64) * 8)
1198 static int encode_metric_spec(void **p, void *end)
1199 {
1200         static const size_t count = ARRAY_SIZE(metric_bits);
1201
1202         /* header */
1203         if (WARN_ON_ONCE(*p + 2 > end))
1204                 return -ERANGE;
1205
1206         ceph_encode_8(p, 1); /* version */
1207         ceph_encode_8(p, 1); /* compat */
1208
1209         if (count > 0) {
1210                 size_t i;
1211                 size_t size = METRIC_BYTES(count);
1212
1213                 if (WARN_ON_ONCE(*p + 4 + 4 + size > end))
1214                         return -ERANGE;
1215
1216                 /* metric spec info length */
1217                 ceph_encode_32(p, 4 + size);
1218
1219                 /* metric spec */
1220                 ceph_encode_32(p, size);
1221                 memset(*p, 0, size);
1222                 for (i = 0; i < count; i++)
1223                         ((unsigned char *)(*p))[i / 8] |= BIT(metric_bits[i] % 8);
1224                 *p += size;
1225         } else {
1226                 if (WARN_ON_ONCE(*p + 4 + 4 > end))
1227                         return -ERANGE;
1228
1229                 /* metric spec info length */
1230                 ceph_encode_32(p, 4);
1231                 /* metric spec */
1232                 ceph_encode_32(p, 0);
1233         }
1234
1235         return 0;
1236 }
1237
1238 /*
1239  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
1240  * to include additional client metadata fields.
1241  */
1242 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
1243 {
1244         struct ceph_msg *msg;
1245         struct ceph_mds_session_head *h;
1246         int i = -1;
1247         int extra_bytes = 0;
1248         int metadata_key_count = 0;
1249         struct ceph_options *opt = mdsc->fsc->client->options;
1250         struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
1251         size_t size, count;
1252         void *p, *end;
1253         int ret;
1254
1255         const char* metadata[][2] = {
1256                 {"hostname", mdsc->nodename},
1257                 {"kernel_version", init_utsname()->release},
1258                 {"entity_id", opt->name ? : ""},
1259                 {"root", fsopt->server_path ? : "/"},
1260                 {NULL, NULL}
1261         };
1262
1263         /* Calculate serialized length of metadata */
1264         extra_bytes = 4;  /* map length */
1265         for (i = 0; metadata[i][0]; ++i) {
1266                 extra_bytes += 8 + strlen(metadata[i][0]) +
1267                         strlen(metadata[i][1]);
1268                 metadata_key_count++;
1269         }
1270
1271         /* supported feature */
1272         size = 0;
1273         count = ARRAY_SIZE(feature_bits);
1274         if (count > 0)
1275                 size = FEATURE_BYTES(count);
1276         extra_bytes += 4 + size;
1277
1278         /* metric spec */
1279         size = 0;
1280         count = ARRAY_SIZE(metric_bits);
1281         if (count > 0)
1282                 size = METRIC_BYTES(count);
1283         extra_bytes += 2 + 4 + 4 + size;
1284
1285         /* Allocate the message */
1286         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + extra_bytes,
1287                            GFP_NOFS, false);
1288         if (!msg) {
1289                 pr_err("create_session_msg ENOMEM creating msg\n");
1290                 return ERR_PTR(-ENOMEM);
1291         }
1292         p = msg->front.iov_base;
1293         end = p + msg->front.iov_len;
1294
1295         h = p;
1296         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
1297         h->seq = cpu_to_le64(seq);
1298
1299         /*
1300          * Serialize client metadata into waiting buffer space, using
1301          * the format that userspace expects for map<string, string>
1302          *
1303          * ClientSession messages with metadata are v4
1304          */
1305         msg->hdr.version = cpu_to_le16(4);
1306         msg->hdr.compat_version = cpu_to_le16(1);
1307
1308         /* The write pointer, following the session_head structure */
1309         p += sizeof(*h);
1310
1311         /* Number of entries in the map */
1312         ceph_encode_32(&p, metadata_key_count);
1313
1314         /* Two length-prefixed strings for each entry in the map */
1315         for (i = 0; metadata[i][0]; ++i) {
1316                 size_t const key_len = strlen(metadata[i][0]);
1317                 size_t const val_len = strlen(metadata[i][1]);
1318
1319                 ceph_encode_32(&p, key_len);
1320                 memcpy(p, metadata[i][0], key_len);
1321                 p += key_len;
1322                 ceph_encode_32(&p, val_len);
1323                 memcpy(p, metadata[i][1], val_len);
1324                 p += val_len;
1325         }
1326
1327         ret = encode_supported_features(&p, end);
1328         if (ret) {
1329                 pr_err("encode_supported_features failed!\n");
1330                 ceph_msg_put(msg);
1331                 return ERR_PTR(ret);
1332         }
1333
1334         ret = encode_metric_spec(&p, end);
1335         if (ret) {
1336                 pr_err("encode_metric_spec failed!\n");
1337                 ceph_msg_put(msg);
1338                 return ERR_PTR(ret);
1339         }
1340
1341         msg->front.iov_len = p - msg->front.iov_base;
1342         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1343
1344         return msg;
1345 }
1346
1347 /*
1348  * send session open request.
1349  *
1350  * called under mdsc->mutex
1351  */
1352 static int __open_session(struct ceph_mds_client *mdsc,
1353                           struct ceph_mds_session *session)
1354 {
1355         struct ceph_msg *msg;
1356         int mstate;
1357         int mds = session->s_mds;
1358
1359         /* wait for mds to go active? */
1360         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
1361         dout("open_session to mds%d (%s)\n", mds,
1362              ceph_mds_state_name(mstate));
1363         session->s_state = CEPH_MDS_SESSION_OPENING;
1364         session->s_renew_requested = jiffies;
1365
1366         /* send connect message */
1367         msg = create_session_open_msg(mdsc, session->s_seq);
1368         if (IS_ERR(msg))
1369                 return PTR_ERR(msg);
1370         ceph_con_send(&session->s_con, msg);
1371         return 0;
1372 }
1373
1374 /*
1375  * open sessions for any export targets for the given mds
1376  *
1377  * called under mdsc->mutex
1378  */
1379 static struct ceph_mds_session *
1380 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
1381 {
1382         struct ceph_mds_session *session;
1383         int ret;
1384
1385         session = __ceph_lookup_mds_session(mdsc, target);
1386         if (!session) {
1387                 session = register_session(mdsc, target);
1388                 if (IS_ERR(session))
1389                         return session;
1390         }
1391         if (session->s_state == CEPH_MDS_SESSION_NEW ||
1392             session->s_state == CEPH_MDS_SESSION_CLOSING) {
1393                 ret = __open_session(mdsc, session);
1394                 if (ret)
1395                         return ERR_PTR(ret);
1396         }
1397
1398         return session;
1399 }
1400
1401 struct ceph_mds_session *
1402 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
1403 {
1404         struct ceph_mds_session *session;
1405
1406         dout("open_export_target_session to mds%d\n", target);
1407
1408         mutex_lock(&mdsc->mutex);
1409         session = __open_export_target_session(mdsc, target);
1410         mutex_unlock(&mdsc->mutex);
1411
1412         return session;
1413 }
1414
1415 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
1416                                           struct ceph_mds_session *session)
1417 {
1418         struct ceph_mds_info *mi;
1419         struct ceph_mds_session *ts;
1420         int i, mds = session->s_mds;
1421
1422         if (mds >= mdsc->mdsmap->possible_max_rank)
1423                 return;
1424
1425         mi = &mdsc->mdsmap->m_info[mds];
1426         dout("open_export_target_sessions for mds%d (%d targets)\n",
1427              session->s_mds, mi->num_export_targets);
1428
1429         for (i = 0; i < mi->num_export_targets; i++) {
1430                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1431                 if (!IS_ERR(ts))
1432                         ceph_put_mds_session(ts);
1433         }
1434 }
1435
1436 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1437                                            struct ceph_mds_session *session)
1438 {
1439         mutex_lock(&mdsc->mutex);
1440         __open_export_target_sessions(mdsc, session);
1441         mutex_unlock(&mdsc->mutex);
1442 }
1443
1444 /*
1445  * session caps
1446  */
1447
1448 static void detach_cap_releases(struct ceph_mds_session *session,
1449                                 struct list_head *target)
1450 {
1451         lockdep_assert_held(&session->s_cap_lock);
1452
1453         list_splice_init(&session->s_cap_releases, target);
1454         session->s_num_cap_releases = 0;
1455         dout("dispose_cap_releases mds%d\n", session->s_mds);
1456 }
1457
1458 static void dispose_cap_releases(struct ceph_mds_client *mdsc,
1459                                  struct list_head *dispose)
1460 {
1461         while (!list_empty(dispose)) {
1462                 struct ceph_cap *cap;
1463                 /* zero out the in-progress message */
1464                 cap = list_first_entry(dispose, struct ceph_cap, session_caps);
1465                 list_del(&cap->session_caps);
1466                 ceph_put_cap(mdsc, cap);
1467         }
1468 }
1469
1470 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1471                                      struct ceph_mds_session *session)
1472 {
1473         struct ceph_mds_request *req;
1474         struct rb_node *p;
1475         struct ceph_inode_info *ci;
1476
1477         dout("cleanup_session_requests mds%d\n", session->s_mds);
1478         mutex_lock(&mdsc->mutex);
1479         while (!list_empty(&session->s_unsafe)) {
1480                 req = list_first_entry(&session->s_unsafe,
1481                                        struct ceph_mds_request, r_unsafe_item);
1482                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1483                                     req->r_tid);
1484                 if (req->r_target_inode) {
1485                         /* dropping unsafe change of inode's attributes */
1486                         ci = ceph_inode(req->r_target_inode);
1487                         errseq_set(&ci->i_meta_err, -EIO);
1488                 }
1489                 if (req->r_unsafe_dir) {
1490                         /* dropping unsafe directory operation */
1491                         ci = ceph_inode(req->r_unsafe_dir);
1492                         errseq_set(&ci->i_meta_err, -EIO);
1493                 }
1494                 __unregister_request(mdsc, req);
1495         }
1496         /* zero r_attempts, so kick_requests() will re-send requests */
1497         p = rb_first(&mdsc->request_tree);
1498         while (p) {
1499                 req = rb_entry(p, struct ceph_mds_request, r_node);
1500                 p = rb_next(p);
1501                 if (req->r_session &&
1502                     req->r_session->s_mds == session->s_mds)
1503                         req->r_attempts = 0;
1504         }
1505         mutex_unlock(&mdsc->mutex);
1506 }
1507
1508 /*
1509  * Helper to safely iterate over all caps associated with a session, with
1510  * special care taken to handle a racing __ceph_remove_cap().
1511  *
1512  * Caller must hold session s_mutex.
1513  */
1514 int ceph_iterate_session_caps(struct ceph_mds_session *session,
1515                               int (*cb)(struct inode *, struct ceph_cap *,
1516                                         void *), void *arg)
1517 {
1518         struct list_head *p;
1519         struct ceph_cap *cap;
1520         struct inode *inode, *last_inode = NULL;
1521         struct ceph_cap *old_cap = NULL;
1522         int ret;
1523
1524         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1525         spin_lock(&session->s_cap_lock);
1526         p = session->s_caps.next;
1527         while (p != &session->s_caps) {
1528                 cap = list_entry(p, struct ceph_cap, session_caps);
1529                 inode = igrab(&cap->ci->vfs_inode);
1530                 if (!inode) {
1531                         p = p->next;
1532                         continue;
1533                 }
1534                 session->s_cap_iterator = cap;
1535                 spin_unlock(&session->s_cap_lock);
1536
1537                 if (last_inode) {
1538                         /* avoid calling iput_final() while holding
1539                          * s_mutex or in mds dispatch threads */
1540                         ceph_async_iput(last_inode);
1541                         last_inode = NULL;
1542                 }
1543                 if (old_cap) {
1544                         ceph_put_cap(session->s_mdsc, old_cap);
1545                         old_cap = NULL;
1546                 }
1547
1548                 ret = cb(inode, cap, arg);
1549                 last_inode = inode;
1550
1551                 spin_lock(&session->s_cap_lock);
1552                 p = p->next;
1553                 if (!cap->ci) {
1554                         dout("iterate_session_caps  finishing cap %p removal\n",
1555                              cap);
1556                         BUG_ON(cap->session != session);
1557                         cap->session = NULL;
1558                         list_del_init(&cap->session_caps);
1559                         session->s_nr_caps--;
1560                         atomic64_dec(&session->s_mdsc->metric.total_caps);
1561                         if (cap->queue_release)
1562                                 __ceph_queue_cap_release(session, cap);
1563                         else
1564                                 old_cap = cap;  /* put_cap it w/o locks held */
1565                 }
1566                 if (ret < 0)
1567                         goto out;
1568         }
1569         ret = 0;
1570 out:
1571         session->s_cap_iterator = NULL;
1572         spin_unlock(&session->s_cap_lock);
1573
1574         ceph_async_iput(last_inode);
1575         if (old_cap)
1576                 ceph_put_cap(session->s_mdsc, old_cap);
1577
1578         return ret;
1579 }
1580
1581 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1582                                   void *arg)
1583 {
1584         struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1585         struct ceph_inode_info *ci = ceph_inode(inode);
1586         LIST_HEAD(to_remove);
1587         bool dirty_dropped = false;
1588         bool invalidate = false;
1589
1590         dout("removing cap %p, ci is %p, inode is %p\n",
1591              cap, ci, &ci->vfs_inode);
1592         spin_lock(&ci->i_ceph_lock);
1593         __ceph_remove_cap(cap, false);
1594         if (!ci->i_auth_cap) {
1595                 struct ceph_cap_flush *cf;
1596                 struct ceph_mds_client *mdsc = fsc->mdsc;
1597
1598                 if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
1599                         if (inode->i_data.nrpages > 0)
1600                                 invalidate = true;
1601                         if (ci->i_wrbuffer_ref > 0)
1602                                 mapping_set_error(&inode->i_data, -EIO);
1603                 }
1604
1605                 while (!list_empty(&ci->i_cap_flush_list)) {
1606                         cf = list_first_entry(&ci->i_cap_flush_list,
1607                                               struct ceph_cap_flush, i_list);
1608                         list_move(&cf->i_list, &to_remove);
1609                 }
1610
1611                 spin_lock(&mdsc->cap_dirty_lock);
1612
1613                 list_for_each_entry(cf, &to_remove, i_list)
1614                         list_del(&cf->g_list);
1615
1616                 if (!list_empty(&ci->i_dirty_item)) {
1617                         pr_warn_ratelimited(
1618                                 " dropping dirty %s state for %p %lld\n",
1619                                 ceph_cap_string(ci->i_dirty_caps),
1620                                 inode, ceph_ino(inode));
1621                         ci->i_dirty_caps = 0;
1622                         list_del_init(&ci->i_dirty_item);
1623                         dirty_dropped = true;
1624                 }
1625                 if (!list_empty(&ci->i_flushing_item)) {
1626                         pr_warn_ratelimited(
1627                                 " dropping dirty+flushing %s state for %p %lld\n",
1628                                 ceph_cap_string(ci->i_flushing_caps),
1629                                 inode, ceph_ino(inode));
1630                         ci->i_flushing_caps = 0;
1631                         list_del_init(&ci->i_flushing_item);
1632                         mdsc->num_cap_flushing--;
1633                         dirty_dropped = true;
1634                 }
1635                 spin_unlock(&mdsc->cap_dirty_lock);
1636
1637                 if (dirty_dropped) {
1638                         errseq_set(&ci->i_meta_err, -EIO);
1639
1640                         if (ci->i_wrbuffer_ref_head == 0 &&
1641                             ci->i_wr_ref == 0 &&
1642                             ci->i_dirty_caps == 0 &&
1643                             ci->i_flushing_caps == 0) {
1644                                 ceph_put_snap_context(ci->i_head_snapc);
1645                                 ci->i_head_snapc = NULL;
1646                         }
1647                 }
1648
1649                 if (atomic_read(&ci->i_filelock_ref) > 0) {
1650                         /* make further file lock syscall return -EIO */
1651                         ci->i_ceph_flags |= CEPH_I_ERROR_FILELOCK;
1652                         pr_warn_ratelimited(" dropping file locks for %p %lld\n",
1653                                             inode, ceph_ino(inode));
1654                 }
1655
1656                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1657                         list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
1658                         ci->i_prealloc_cap_flush = NULL;
1659                 }
1660         }
1661         spin_unlock(&ci->i_ceph_lock);
1662         while (!list_empty(&to_remove)) {
1663                 struct ceph_cap_flush *cf;
1664                 cf = list_first_entry(&to_remove,
1665                                       struct ceph_cap_flush, i_list);
1666                 list_del(&cf->i_list);
1667                 ceph_free_cap_flush(cf);
1668         }
1669
1670         wake_up_all(&ci->i_cap_wq);
1671         if (invalidate)
1672                 ceph_queue_invalidate(inode);
1673         if (dirty_dropped)
1674                 iput(inode);
1675         return 0;
1676 }
1677
1678 /*
1679  * caller must hold session s_mutex
1680  */
1681 static void remove_session_caps(struct ceph_mds_session *session)
1682 {
1683         struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1684         struct super_block *sb = fsc->sb;
1685         LIST_HEAD(dispose);
1686
1687         dout("remove_session_caps on %p\n", session);
1688         ceph_iterate_session_caps(session, remove_session_caps_cb, fsc);
1689
1690         wake_up_all(&fsc->mdsc->cap_flushing_wq);
1691
1692         spin_lock(&session->s_cap_lock);
1693         if (session->s_nr_caps > 0) {
1694                 struct inode *inode;
1695                 struct ceph_cap *cap, *prev = NULL;
1696                 struct ceph_vino vino;
1697                 /*
1698                  * iterate_session_caps() skips inodes that are being
1699                  * deleted, we need to wait until deletions are complete.
1700                  * __wait_on_freeing_inode() is designed for the job,
1701                  * but it is not exported, so use lookup inode function
1702                  * to access it.
1703                  */
1704                 while (!list_empty(&session->s_caps)) {
1705                         cap = list_entry(session->s_caps.next,
1706                                          struct ceph_cap, session_caps);
1707                         if (cap == prev)
1708                                 break;
1709                         prev = cap;
1710                         vino = cap->ci->i_vino;
1711                         spin_unlock(&session->s_cap_lock);
1712
1713                         inode = ceph_find_inode(sb, vino);
1714                          /* avoid calling iput_final() while holding s_mutex */
1715                         ceph_async_iput(inode);
1716
1717                         spin_lock(&session->s_cap_lock);
1718                 }
1719         }
1720
1721         // drop cap expires and unlock s_cap_lock
1722         detach_cap_releases(session, &dispose);
1723
1724         BUG_ON(session->s_nr_caps > 0);
1725         BUG_ON(!list_empty(&session->s_cap_flushing));
1726         spin_unlock(&session->s_cap_lock);
1727         dispose_cap_releases(session->s_mdsc, &dispose);
1728 }
1729
1730 enum {
1731         RECONNECT,
1732         RENEWCAPS,
1733         FORCE_RO,
1734 };
1735
1736 /*
1737  * wake up any threads waiting on this session's caps.  if the cap is
1738  * old (didn't get renewed on the client reconnect), remove it now.
1739  *
1740  * caller must hold s_mutex.
1741  */
1742 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1743                               void *arg)
1744 {
1745         struct ceph_inode_info *ci = ceph_inode(inode);
1746         unsigned long ev = (unsigned long)arg;
1747
1748         if (ev == RECONNECT) {
1749                 spin_lock(&ci->i_ceph_lock);
1750                 ci->i_wanted_max_size = 0;
1751                 ci->i_requested_max_size = 0;
1752                 spin_unlock(&ci->i_ceph_lock);
1753         } else if (ev == RENEWCAPS) {
1754                 if (cap->cap_gen < cap->session->s_cap_gen) {
1755                         /* mds did not re-issue stale cap */
1756                         spin_lock(&ci->i_ceph_lock);
1757                         cap->issued = cap->implemented = CEPH_CAP_PIN;
1758                         spin_unlock(&ci->i_ceph_lock);
1759                 }
1760         } else if (ev == FORCE_RO) {
1761         }
1762         wake_up_all(&ci->i_cap_wq);
1763         return 0;
1764 }
1765
1766 static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
1767 {
1768         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1769         ceph_iterate_session_caps(session, wake_up_session_cb,
1770                                   (void *)(unsigned long)ev);
1771 }
1772
1773 /*
1774  * Send periodic message to MDS renewing all currently held caps.  The
1775  * ack will reset the expiration for all caps from this session.
1776  *
1777  * caller holds s_mutex
1778  */
1779 static int send_renew_caps(struct ceph_mds_client *mdsc,
1780                            struct ceph_mds_session *session)
1781 {
1782         struct ceph_msg *msg;
1783         int state;
1784
1785         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1786             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1787                 pr_info("mds%d caps stale\n", session->s_mds);
1788         session->s_renew_requested = jiffies;
1789
1790         /* do not try to renew caps until a recovering mds has reconnected
1791          * with its clients. */
1792         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1793         if (state < CEPH_MDS_STATE_RECONNECT) {
1794                 dout("send_renew_caps ignoring mds%d (%s)\n",
1795                      session->s_mds, ceph_mds_state_name(state));
1796                 return 0;
1797         }
1798
1799         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1800                 ceph_mds_state_name(state));
1801         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1802                                  ++session->s_renew_seq);
1803         if (!msg)
1804                 return -ENOMEM;
1805         ceph_con_send(&session->s_con, msg);
1806         return 0;
1807 }
1808
1809 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1810                              struct ceph_mds_session *session, u64 seq)
1811 {
1812         struct ceph_msg *msg;
1813
1814         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1815              session->s_mds, ceph_session_state_name(session->s_state), seq);
1816         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1817         if (!msg)
1818                 return -ENOMEM;
1819         ceph_con_send(&session->s_con, msg);
1820         return 0;
1821 }
1822
1823
1824 /*
1825  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1826  *
1827  * Called under session->s_mutex
1828  */
1829 static void renewed_caps(struct ceph_mds_client *mdsc,
1830                          struct ceph_mds_session *session, int is_renew)
1831 {
1832         int was_stale;
1833         int wake = 0;
1834
1835         spin_lock(&session->s_cap_lock);
1836         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1837
1838         session->s_cap_ttl = session->s_renew_requested +
1839                 mdsc->mdsmap->m_session_timeout*HZ;
1840
1841         if (was_stale) {
1842                 if (time_before(jiffies, session->s_cap_ttl)) {
1843                         pr_info("mds%d caps renewed\n", session->s_mds);
1844                         wake = 1;
1845                 } else {
1846                         pr_info("mds%d caps still stale\n", session->s_mds);
1847                 }
1848         }
1849         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1850              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1851              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1852         spin_unlock(&session->s_cap_lock);
1853
1854         if (wake)
1855                 wake_up_session_caps(session, RENEWCAPS);
1856 }
1857
1858 /*
1859  * send a session close request
1860  */
1861 static int request_close_session(struct ceph_mds_session *session)
1862 {
1863         struct ceph_msg *msg;
1864
1865         dout("request_close_session mds%d state %s seq %lld\n",
1866              session->s_mds, ceph_session_state_name(session->s_state),
1867              session->s_seq);
1868         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1869         if (!msg)
1870                 return -ENOMEM;
1871         ceph_con_send(&session->s_con, msg);
1872         return 1;
1873 }
1874
1875 /*
1876  * Called with s_mutex held.
1877  */
1878 static int __close_session(struct ceph_mds_client *mdsc,
1879                          struct ceph_mds_session *session)
1880 {
1881         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1882                 return 0;
1883         session->s_state = CEPH_MDS_SESSION_CLOSING;
1884         return request_close_session(session);
1885 }
1886
1887 static bool drop_negative_children(struct dentry *dentry)
1888 {
1889         struct dentry *child;
1890         bool all_negative = true;
1891
1892         if (!d_is_dir(dentry))
1893                 goto out;
1894
1895         spin_lock(&dentry->d_lock);
1896         list_for_each_entry(child, &dentry->d_subdirs, d_child) {
1897                 if (d_really_is_positive(child)) {
1898                         all_negative = false;
1899                         break;
1900                 }
1901         }
1902         spin_unlock(&dentry->d_lock);
1903
1904         if (all_negative)
1905                 shrink_dcache_parent(dentry);
1906 out:
1907         return all_negative;
1908 }
1909
1910 /*
1911  * Trim old(er) caps.
1912  *
1913  * Because we can't cache an inode without one or more caps, we do
1914  * this indirectly: if a cap is unused, we prune its aliases, at which
1915  * point the inode will hopefully get dropped to.
1916  *
1917  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1918  * memory pressure from the MDS, though, so it needn't be perfect.
1919  */
1920 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1921 {
1922         int *remaining = arg;
1923         struct ceph_inode_info *ci = ceph_inode(inode);
1924         int used, wanted, oissued, mine;
1925
1926         if (*remaining <= 0)
1927                 return -1;
1928
1929         spin_lock(&ci->i_ceph_lock);
1930         mine = cap->issued | cap->implemented;
1931         used = __ceph_caps_used(ci);
1932         wanted = __ceph_caps_file_wanted(ci);
1933         oissued = __ceph_caps_issued_other(ci, cap);
1934
1935         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1936              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1937              ceph_cap_string(used), ceph_cap_string(wanted));
1938         if (cap == ci->i_auth_cap) {
1939                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1940                     !list_empty(&ci->i_cap_snaps))
1941                         goto out;
1942                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1943                         goto out;
1944                 /* Note: it's possible that i_filelock_ref becomes non-zero
1945                  * after dropping auth caps. It doesn't hurt because reply
1946                  * of lock mds request will re-add auth caps. */
1947                 if (atomic_read(&ci->i_filelock_ref) > 0)
1948                         goto out;
1949         }
1950         /* The inode has cached pages, but it's no longer used.
1951          * we can safely drop it */
1952         if (S_ISREG(inode->i_mode) &&
1953             wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1954             !(oissued & CEPH_CAP_FILE_CACHE)) {
1955           used = 0;
1956           oissued = 0;
1957         }
1958         if ((used | wanted) & ~oissued & mine)
1959                 goto out;   /* we need these caps */
1960
1961         if (oissued) {
1962                 /* we aren't the only cap.. just remove us */
1963                 __ceph_remove_cap(cap, true);
1964                 (*remaining)--;
1965         } else {
1966                 struct dentry *dentry;
1967                 /* try dropping referring dentries */
1968                 spin_unlock(&ci->i_ceph_lock);
1969                 dentry = d_find_any_alias(inode);
1970                 if (dentry && drop_negative_children(dentry)) {
1971                         int count;
1972                         dput(dentry);
1973                         d_prune_aliases(inode);
1974                         count = atomic_read(&inode->i_count);
1975                         if (count == 1)
1976                                 (*remaining)--;
1977                         dout("trim_caps_cb %p cap %p pruned, count now %d\n",
1978                              inode, cap, count);
1979                 } else {
1980                         dput(dentry);
1981                 }
1982                 return 0;
1983         }
1984
1985 out:
1986         spin_unlock(&ci->i_ceph_lock);
1987         return 0;
1988 }
1989
1990 /*
1991  * Trim session cap count down to some max number.
1992  */
1993 int ceph_trim_caps(struct ceph_mds_client *mdsc,
1994                    struct ceph_mds_session *session,
1995                    int max_caps)
1996 {
1997         int trim_caps = session->s_nr_caps - max_caps;
1998
1999         dout("trim_caps mds%d start: %d / %d, trim %d\n",
2000              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
2001         if (trim_caps > 0) {
2002                 int remaining = trim_caps;
2003
2004                 ceph_iterate_session_caps(session, trim_caps_cb, &remaining);
2005                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
2006                      session->s_mds, session->s_nr_caps, max_caps,
2007                         trim_caps - remaining);
2008         }
2009
2010         ceph_flush_cap_releases(mdsc, session);
2011         return 0;
2012 }
2013
2014 static int check_caps_flush(struct ceph_mds_client *mdsc,
2015                             u64 want_flush_tid)
2016 {
2017         int ret = 1;
2018
2019         spin_lock(&mdsc->cap_dirty_lock);
2020         if (!list_empty(&mdsc->cap_flush_list)) {
2021                 struct ceph_cap_flush *cf =
2022                         list_first_entry(&mdsc->cap_flush_list,
2023                                          struct ceph_cap_flush, g_list);
2024                 if (cf->tid <= want_flush_tid) {
2025                         dout("check_caps_flush still flushing tid "
2026                              "%llu <= %llu\n", cf->tid, want_flush_tid);
2027                         ret = 0;
2028                 }
2029         }
2030         spin_unlock(&mdsc->cap_dirty_lock);
2031         return ret;
2032 }
2033
2034 /*
2035  * flush all dirty inode data to disk.
2036  *
2037  * returns true if we've flushed through want_flush_tid
2038  */
2039 static void wait_caps_flush(struct ceph_mds_client *mdsc,
2040                             u64 want_flush_tid)
2041 {
2042         dout("check_caps_flush want %llu\n", want_flush_tid);
2043
2044         wait_event(mdsc->cap_flushing_wq,
2045                    check_caps_flush(mdsc, want_flush_tid));
2046
2047         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
2048 }
2049
2050 /*
2051  * called under s_mutex
2052  */
2053 static void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
2054                                    struct ceph_mds_session *session)
2055 {
2056         struct ceph_msg *msg = NULL;
2057         struct ceph_mds_cap_release *head;
2058         struct ceph_mds_cap_item *item;
2059         struct ceph_osd_client *osdc = &mdsc->fsc->client->osdc;
2060         struct ceph_cap *cap;
2061         LIST_HEAD(tmp_list);
2062         int num_cap_releases;
2063         __le32  barrier, *cap_barrier;
2064
2065         down_read(&osdc->lock);
2066         barrier = cpu_to_le32(osdc->epoch_barrier);
2067         up_read(&osdc->lock);
2068
2069         spin_lock(&session->s_cap_lock);
2070 again:
2071         list_splice_init(&session->s_cap_releases, &tmp_list);
2072         num_cap_releases = session->s_num_cap_releases;
2073         session->s_num_cap_releases = 0;
2074         spin_unlock(&session->s_cap_lock);
2075
2076         while (!list_empty(&tmp_list)) {
2077                 if (!msg) {
2078                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
2079                                         PAGE_SIZE, GFP_NOFS, false);
2080                         if (!msg)
2081                                 goto out_err;
2082                         head = msg->front.iov_base;
2083                         head->num = cpu_to_le32(0);
2084                         msg->front.iov_len = sizeof(*head);
2085
2086                         msg->hdr.version = cpu_to_le16(2);
2087                         msg->hdr.compat_version = cpu_to_le16(1);
2088                 }
2089
2090                 cap = list_first_entry(&tmp_list, struct ceph_cap,
2091                                         session_caps);
2092                 list_del(&cap->session_caps);
2093                 num_cap_releases--;
2094
2095                 head = msg->front.iov_base;
2096                 put_unaligned_le32(get_unaligned_le32(&head->num) + 1,
2097                                    &head->num);
2098                 item = msg->front.iov_base + msg->front.iov_len;
2099                 item->ino = cpu_to_le64(cap->cap_ino);
2100                 item->cap_id = cpu_to_le64(cap->cap_id);
2101                 item->migrate_seq = cpu_to_le32(cap->mseq);
2102                 item->seq = cpu_to_le32(cap->issue_seq);
2103                 msg->front.iov_len += sizeof(*item);
2104
2105                 ceph_put_cap(mdsc, cap);
2106
2107                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
2108                         // Append cap_barrier field
2109                         cap_barrier = msg->front.iov_base + msg->front.iov_len;
2110                         *cap_barrier = barrier;
2111                         msg->front.iov_len += sizeof(*cap_barrier);
2112
2113                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2114                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
2115                         ceph_con_send(&session->s_con, msg);
2116                         msg = NULL;
2117                 }
2118         }
2119
2120         BUG_ON(num_cap_releases != 0);
2121
2122         spin_lock(&session->s_cap_lock);
2123         if (!list_empty(&session->s_cap_releases))
2124                 goto again;
2125         spin_unlock(&session->s_cap_lock);
2126
2127         if (msg) {
2128                 // Append cap_barrier field
2129                 cap_barrier = msg->front.iov_base + msg->front.iov_len;
2130                 *cap_barrier = barrier;
2131                 msg->front.iov_len += sizeof(*cap_barrier);
2132
2133                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2134                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
2135                 ceph_con_send(&session->s_con, msg);
2136         }
2137         return;
2138 out_err:
2139         pr_err("send_cap_releases mds%d, failed to allocate message\n",
2140                 session->s_mds);
2141         spin_lock(&session->s_cap_lock);
2142         list_splice(&tmp_list, &session->s_cap_releases);
2143         session->s_num_cap_releases += num_cap_releases;
2144         spin_unlock(&session->s_cap_lock);
2145 }
2146
2147 static void ceph_cap_release_work(struct work_struct *work)
2148 {
2149         struct ceph_mds_session *session =
2150                 container_of(work, struct ceph_mds_session, s_cap_release_work);
2151
2152         mutex_lock(&session->s_mutex);
2153         if (session->s_state == CEPH_MDS_SESSION_OPEN ||
2154             session->s_state == CEPH_MDS_SESSION_HUNG)
2155                 ceph_send_cap_releases(session->s_mdsc, session);
2156         mutex_unlock(&session->s_mutex);
2157         ceph_put_mds_session(session);
2158 }
2159
2160 void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
2161                              struct ceph_mds_session *session)
2162 {
2163         if (mdsc->stopping)
2164                 return;
2165
2166         ceph_get_mds_session(session);
2167         if (queue_work(mdsc->fsc->cap_wq,
2168                        &session->s_cap_release_work)) {
2169                 dout("cap release work queued\n");
2170         } else {
2171                 ceph_put_mds_session(session);
2172                 dout("failed to queue cap release work\n");
2173         }
2174 }
2175
2176 /*
2177  * caller holds session->s_cap_lock
2178  */
2179 void __ceph_queue_cap_release(struct ceph_mds_session *session,
2180                               struct ceph_cap *cap)
2181 {
2182         list_add_tail(&cap->session_caps, &session->s_cap_releases);
2183         session->s_num_cap_releases++;
2184
2185         if (!(session->s_num_cap_releases % CEPH_CAPS_PER_RELEASE))
2186                 ceph_flush_cap_releases(session->s_mdsc, session);
2187 }
2188
2189 static void ceph_cap_reclaim_work(struct work_struct *work)
2190 {
2191         struct ceph_mds_client *mdsc =
2192                 container_of(work, struct ceph_mds_client, cap_reclaim_work);
2193         int ret = ceph_trim_dentries(mdsc);
2194         if (ret == -EAGAIN)
2195                 ceph_queue_cap_reclaim_work(mdsc);
2196 }
2197
2198 void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc)
2199 {
2200         if (mdsc->stopping)
2201                 return;
2202
2203         if (queue_work(mdsc->fsc->cap_wq, &mdsc->cap_reclaim_work)) {
2204                 dout("caps reclaim work queued\n");
2205         } else {
2206                 dout("failed to queue caps release work\n");
2207         }
2208 }
2209
2210 void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr)
2211 {
2212         int val;
2213         if (!nr)
2214                 return;
2215         val = atomic_add_return(nr, &mdsc->cap_reclaim_pending);
2216         if ((val % CEPH_CAPS_PER_RELEASE) < nr) {
2217                 atomic_set(&mdsc->cap_reclaim_pending, 0);
2218                 ceph_queue_cap_reclaim_work(mdsc);
2219         }
2220 }
2221
2222 /*
2223  * requests
2224  */
2225
2226 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
2227                                     struct inode *dir)
2228 {
2229         struct ceph_inode_info *ci = ceph_inode(dir);
2230         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
2231         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
2232         size_t size = sizeof(struct ceph_mds_reply_dir_entry);
2233         unsigned int num_entries;
2234         int order;
2235
2236         spin_lock(&ci->i_ceph_lock);
2237         num_entries = ci->i_files + ci->i_subdirs;
2238         spin_unlock(&ci->i_ceph_lock);
2239         num_entries = max(num_entries, 1U);
2240         num_entries = min(num_entries, opt->max_readdir);
2241
2242         order = get_order(size * num_entries);
2243         while (order >= 0) {
2244                 rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
2245                                                              __GFP_NOWARN,
2246                                                              order);
2247                 if (rinfo->dir_entries)
2248                         break;
2249                 order--;
2250         }
2251         if (!rinfo->dir_entries)
2252                 return -ENOMEM;
2253
2254         num_entries = (PAGE_SIZE << order) / size;
2255         num_entries = min(num_entries, opt->max_readdir);
2256
2257         rinfo->dir_buf_size = PAGE_SIZE << order;
2258         req->r_num_caps = num_entries + 1;
2259         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
2260         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
2261         return 0;
2262 }
2263
2264 /*
2265  * Create an mds request.
2266  */
2267 struct ceph_mds_request *
2268 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
2269 {
2270         struct ceph_mds_request *req;
2271
2272         req = kmem_cache_zalloc(ceph_mds_request_cachep, GFP_NOFS);
2273         if (!req)
2274                 return ERR_PTR(-ENOMEM);
2275
2276         mutex_init(&req->r_fill_mutex);
2277         req->r_mdsc = mdsc;
2278         req->r_started = jiffies;
2279         req->r_start_latency = ktime_get();
2280         req->r_resend_mds = -1;
2281         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
2282         INIT_LIST_HEAD(&req->r_unsafe_target_item);
2283         req->r_fmode = -1;
2284         kref_init(&req->r_kref);
2285         RB_CLEAR_NODE(&req->r_node);
2286         INIT_LIST_HEAD(&req->r_wait);
2287         init_completion(&req->r_completion);
2288         init_completion(&req->r_safe_completion);
2289         INIT_LIST_HEAD(&req->r_unsafe_item);
2290
2291         ktime_get_coarse_real_ts64(&req->r_stamp);
2292
2293         req->r_op = op;
2294         req->r_direct_mode = mode;
2295         return req;
2296 }
2297
2298 /*
2299  * return oldest (lowest) request, tid in request tree, 0 if none.
2300  *
2301  * called under mdsc->mutex.
2302  */
2303 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
2304 {
2305         if (RB_EMPTY_ROOT(&mdsc->request_tree))
2306                 return NULL;
2307         return rb_entry(rb_first(&mdsc->request_tree),
2308                         struct ceph_mds_request, r_node);
2309 }
2310
2311 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
2312 {
2313         return mdsc->oldest_tid;
2314 }
2315
2316 /*
2317  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
2318  * on build_path_from_dentry in fs/cifs/dir.c.
2319  *
2320  * If @stop_on_nosnap, generate path relative to the first non-snapped
2321  * inode.
2322  *
2323  * Encode hidden .snap dirs as a double /, i.e.
2324  *   foo/.snap/bar -> foo//bar
2325  */
2326 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
2327                            int stop_on_nosnap)
2328 {
2329         struct dentry *temp;
2330         char *path;
2331         int pos;
2332         unsigned seq;
2333         u64 base;
2334
2335         if (!dentry)
2336                 return ERR_PTR(-EINVAL);
2337
2338         path = __getname();
2339         if (!path)
2340                 return ERR_PTR(-ENOMEM);
2341 retry:
2342         pos = PATH_MAX - 1;
2343         path[pos] = '\0';
2344
2345         seq = read_seqbegin(&rename_lock);
2346         rcu_read_lock();
2347         temp = dentry;
2348         for (;;) {
2349                 struct inode *inode;
2350
2351                 spin_lock(&temp->d_lock);
2352                 inode = d_inode(temp);
2353                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
2354                         dout("build_path path+%d: %p SNAPDIR\n",
2355                              pos, temp);
2356                 } else if (stop_on_nosnap && inode && dentry != temp &&
2357                            ceph_snap(inode) == CEPH_NOSNAP) {
2358                         spin_unlock(&temp->d_lock);
2359                         pos++; /* get rid of any prepended '/' */
2360                         break;
2361                 } else {
2362                         pos -= temp->d_name.len;
2363                         if (pos < 0) {
2364                                 spin_unlock(&temp->d_lock);
2365                                 break;
2366                         }
2367                         memcpy(path + pos, temp->d_name.name, temp->d_name.len);
2368                 }
2369                 spin_unlock(&temp->d_lock);
2370                 temp = READ_ONCE(temp->d_parent);
2371
2372                 /* Are we at the root? */
2373                 if (IS_ROOT(temp))
2374                         break;
2375
2376                 /* Are we out of buffer? */
2377                 if (--pos < 0)
2378                         break;
2379
2380                 path[pos] = '/';
2381         }
2382         base = ceph_ino(d_inode(temp));
2383         rcu_read_unlock();
2384
2385         if (read_seqretry(&rename_lock, seq))
2386                 goto retry;
2387
2388         if (pos < 0) {
2389                 /*
2390                  * A rename didn't occur, but somehow we didn't end up where
2391                  * we thought we would. Throw a warning and try again.
2392                  */
2393                 pr_warn("build_path did not end path lookup where "
2394                         "expected, pos is %d\n", pos);
2395                 goto retry;
2396         }
2397
2398         *pbase = base;
2399         *plen = PATH_MAX - 1 - pos;
2400         dout("build_path on %p %d built %llx '%.*s'\n",
2401              dentry, d_count(dentry), base, *plen, path + pos);
2402         return path + pos;
2403 }
2404
2405 static int build_dentry_path(struct dentry *dentry, struct inode *dir,
2406                              const char **ppath, int *ppathlen, u64 *pino,
2407                              bool *pfreepath, bool parent_locked)
2408 {
2409         char *path;
2410
2411         rcu_read_lock();
2412         if (!dir)
2413                 dir = d_inode_rcu(dentry->d_parent);
2414         if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) {
2415                 *pino = ceph_ino(dir);
2416                 rcu_read_unlock();
2417                 *ppath = dentry->d_name.name;
2418                 *ppathlen = dentry->d_name.len;
2419                 return 0;
2420         }
2421         rcu_read_unlock();
2422         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2423         if (IS_ERR(path))
2424                 return PTR_ERR(path);
2425         *ppath = path;
2426         *pfreepath = true;
2427         return 0;
2428 }
2429
2430 static int build_inode_path(struct inode *inode,
2431                             const char **ppath, int *ppathlen, u64 *pino,
2432                             bool *pfreepath)
2433 {
2434         struct dentry *dentry;
2435         char *path;
2436
2437         if (ceph_snap(inode) == CEPH_NOSNAP) {
2438                 *pino = ceph_ino(inode);
2439                 *ppathlen = 0;
2440                 return 0;
2441         }
2442         dentry = d_find_alias(inode);
2443         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2444         dput(dentry);
2445         if (IS_ERR(path))
2446                 return PTR_ERR(path);
2447         *ppath = path;
2448         *pfreepath = true;
2449         return 0;
2450 }
2451
2452 /*
2453  * request arguments may be specified via an inode *, a dentry *, or
2454  * an explicit ino+path.
2455  */
2456 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
2457                                   struct inode *rdiri, const char *rpath,
2458                                   u64 rino, const char **ppath, int *pathlen,
2459                                   u64 *ino, bool *freepath, bool parent_locked)
2460 {
2461         int r = 0;
2462
2463         if (rinode) {
2464                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
2465                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
2466                      ceph_snap(rinode));
2467         } else if (rdentry) {
2468                 r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
2469                                         freepath, parent_locked);
2470                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
2471                      *ppath);
2472         } else if (rpath || rino) {
2473                 *ino = rino;
2474                 *ppath = rpath;
2475                 *pathlen = rpath ? strlen(rpath) : 0;
2476                 dout(" path %.*s\n", *pathlen, rpath);
2477         }
2478
2479         return r;
2480 }
2481
2482 /*
2483  * called under mdsc->mutex
2484  */
2485 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
2486                                                struct ceph_mds_request *req,
2487                                                int mds, bool drop_cap_releases)
2488 {
2489         struct ceph_msg *msg;
2490         struct ceph_mds_request_head *head;
2491         const char *path1 = NULL;
2492         const char *path2 = NULL;
2493         u64 ino1 = 0, ino2 = 0;
2494         int pathlen1 = 0, pathlen2 = 0;
2495         bool freepath1 = false, freepath2 = false;
2496         int len;
2497         u16 releases;
2498         void *p, *end;
2499         int ret;
2500
2501         ret = set_request_path_attr(req->r_inode, req->r_dentry,
2502                               req->r_parent, req->r_path1, req->r_ino1.ino,
2503                               &path1, &pathlen1, &ino1, &freepath1,
2504                               test_bit(CEPH_MDS_R_PARENT_LOCKED,
2505                                         &req->r_req_flags));
2506         if (ret < 0) {
2507                 msg = ERR_PTR(ret);
2508                 goto out;
2509         }
2510
2511         /* If r_old_dentry is set, then assume that its parent is locked */
2512         ret = set_request_path_attr(NULL, req->r_old_dentry,
2513                               req->r_old_dentry_dir,
2514                               req->r_path2, req->r_ino2.ino,
2515                               &path2, &pathlen2, &ino2, &freepath2, true);
2516         if (ret < 0) {
2517                 msg = ERR_PTR(ret);
2518                 goto out_free1;
2519         }
2520
2521         len = sizeof(*head) +
2522                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
2523                 sizeof(struct ceph_timespec);
2524
2525         /* calculate (max) length for cap releases */
2526         len += sizeof(struct ceph_mds_request_release) *
2527                 (!!req->r_inode_drop + !!req->r_dentry_drop +
2528                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
2529         if (req->r_dentry_drop)
2530                 len += pathlen1;
2531         if (req->r_old_dentry_drop)
2532                 len += pathlen2;
2533
2534         msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
2535         if (!msg) {
2536                 msg = ERR_PTR(-ENOMEM);
2537                 goto out_free2;
2538         }
2539
2540         msg->hdr.version = cpu_to_le16(2);
2541         msg->hdr.tid = cpu_to_le64(req->r_tid);
2542
2543         head = msg->front.iov_base;
2544         p = msg->front.iov_base + sizeof(*head);
2545         end = msg->front.iov_base + msg->front.iov_len;
2546
2547         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
2548         head->op = cpu_to_le32(req->r_op);
2549         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
2550         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
2551         head->ino = cpu_to_le64(req->r_deleg_ino);
2552         head->args = req->r_args;
2553
2554         ceph_encode_filepath(&p, end, ino1, path1);
2555         ceph_encode_filepath(&p, end, ino2, path2);
2556
2557         /* make note of release offset, in case we need to replay */
2558         req->r_request_release_offset = p - msg->front.iov_base;
2559
2560         /* cap releases */
2561         releases = 0;
2562         if (req->r_inode_drop)
2563                 releases += ceph_encode_inode_release(&p,
2564                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
2565                       mds, req->r_inode_drop, req->r_inode_unless,
2566                       req->r_op == CEPH_MDS_OP_READDIR);
2567         if (req->r_dentry_drop)
2568                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
2569                                 req->r_parent, mds, req->r_dentry_drop,
2570                                 req->r_dentry_unless);
2571         if (req->r_old_dentry_drop)
2572                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2573                                 req->r_old_dentry_dir, mds,
2574                                 req->r_old_dentry_drop,
2575                                 req->r_old_dentry_unless);
2576         if (req->r_old_inode_drop)
2577                 releases += ceph_encode_inode_release(&p,
2578                       d_inode(req->r_old_dentry),
2579                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2580
2581         if (drop_cap_releases) {
2582                 releases = 0;
2583                 p = msg->front.iov_base + req->r_request_release_offset;
2584         }
2585
2586         head->num_releases = cpu_to_le16(releases);
2587
2588         /* time stamp */
2589         {
2590                 struct ceph_timespec ts;
2591                 ceph_encode_timespec64(&ts, &req->r_stamp);
2592                 ceph_encode_copy(&p, &ts, sizeof(ts));
2593         }
2594
2595         if (WARN_ON_ONCE(p > end)) {
2596                 ceph_msg_put(msg);
2597                 msg = ERR_PTR(-ERANGE);
2598                 goto out_free2;
2599         }
2600
2601         msg->front.iov_len = p - msg->front.iov_base;
2602         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2603
2604         if (req->r_pagelist) {
2605                 struct ceph_pagelist *pagelist = req->r_pagelist;
2606                 ceph_msg_data_add_pagelist(msg, pagelist);
2607                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2608         } else {
2609                 msg->hdr.data_len = 0;
2610         }
2611
2612         msg->hdr.data_off = cpu_to_le16(0);
2613
2614 out_free2:
2615         if (freepath2)
2616                 ceph_mdsc_free_path((char *)path2, pathlen2);
2617 out_free1:
2618         if (freepath1)
2619                 ceph_mdsc_free_path((char *)path1, pathlen1);
2620 out:
2621         return msg;
2622 }
2623
2624 /*
2625  * called under mdsc->mutex if error, under no mutex if
2626  * success.
2627  */
2628 static void complete_request(struct ceph_mds_client *mdsc,
2629                              struct ceph_mds_request *req)
2630 {
2631         req->r_end_latency = ktime_get();
2632
2633         if (req->r_callback)
2634                 req->r_callback(mdsc, req);
2635         complete_all(&req->r_completion);
2636 }
2637
2638 /*
2639  * called under mdsc->mutex
2640  */
2641 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2642                                   struct ceph_mds_request *req,
2643                                   int mds, bool drop_cap_releases)
2644 {
2645         struct ceph_mds_request_head *rhead;
2646         struct ceph_msg *msg;
2647         int flags = 0;
2648
2649         req->r_attempts++;
2650         if (req->r_inode) {
2651                 struct ceph_cap *cap =
2652                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2653
2654                 if (cap)
2655                         req->r_sent_on_mseq = cap->mseq;
2656                 else
2657                         req->r_sent_on_mseq = -1;
2658         }
2659         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2660              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2661
2662         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2663                 void *p;
2664                 /*
2665                  * Replay.  Do not regenerate message (and rebuild
2666                  * paths, etc.); just use the original message.
2667                  * Rebuilding paths will break for renames because
2668                  * d_move mangles the src name.
2669                  */
2670                 msg = req->r_request;
2671                 rhead = msg->front.iov_base;
2672
2673                 flags = le32_to_cpu(rhead->flags);
2674                 flags |= CEPH_MDS_FLAG_REPLAY;
2675                 rhead->flags = cpu_to_le32(flags);
2676
2677                 if (req->r_target_inode)
2678                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2679
2680                 rhead->num_retry = req->r_attempts - 1;
2681
2682                 /* remove cap/dentry releases from message */
2683                 rhead->num_releases = 0;
2684
2685                 /* time stamp */
2686                 p = msg->front.iov_base + req->r_request_release_offset;
2687                 {
2688                         struct ceph_timespec ts;
2689                         ceph_encode_timespec64(&ts, &req->r_stamp);
2690                         ceph_encode_copy(&p, &ts, sizeof(ts));
2691                 }
2692
2693                 msg->front.iov_len = p - msg->front.iov_base;
2694                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2695                 return 0;
2696         }
2697
2698         if (req->r_request) {
2699                 ceph_msg_put(req->r_request);
2700                 req->r_request = NULL;
2701         }
2702         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2703         if (IS_ERR(msg)) {
2704                 req->r_err = PTR_ERR(msg);
2705                 return PTR_ERR(msg);
2706         }
2707         req->r_request = msg;
2708
2709         rhead = msg->front.iov_base;
2710         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2711         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2712                 flags |= CEPH_MDS_FLAG_REPLAY;
2713         if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags))
2714                 flags |= CEPH_MDS_FLAG_ASYNC;
2715         if (req->r_parent)
2716                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2717         rhead->flags = cpu_to_le32(flags);
2718         rhead->num_fwd = req->r_num_fwd;
2719         rhead->num_retry = req->r_attempts - 1;
2720
2721         dout(" r_parent = %p\n", req->r_parent);
2722         return 0;
2723 }
2724
2725 /*
2726  * called under mdsc->mutex
2727  */
2728 static int __send_request(struct ceph_mds_client *mdsc,
2729                           struct ceph_mds_session *session,
2730                           struct ceph_mds_request *req,
2731                           bool drop_cap_releases)
2732 {
2733         int err;
2734
2735         err = __prepare_send_request(mdsc, req, session->s_mds,
2736                                      drop_cap_releases);
2737         if (!err) {
2738                 ceph_msg_get(req->r_request);
2739                 ceph_con_send(&session->s_con, req->r_request);
2740         }
2741
2742         return err;
2743 }
2744
2745 /*
2746  * send request, or put it on the appropriate wait list.
2747  */
2748 static void __do_request(struct ceph_mds_client *mdsc,
2749                         struct ceph_mds_request *req)
2750 {
2751         struct ceph_mds_session *session = NULL;
2752         int mds = -1;
2753         int err = 0;
2754         bool random;
2755
2756         if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2757                 if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2758                         __unregister_request(mdsc, req);
2759                 return;
2760         }
2761
2762         if (req->r_timeout &&
2763             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2764                 dout("do_request timed out\n");
2765                 err = -ETIMEDOUT;
2766                 goto finish;
2767         }
2768         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2769                 dout("do_request forced umount\n");
2770                 err = -EIO;
2771                 goto finish;
2772         }
2773         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2774                 if (mdsc->mdsmap_err) {
2775                         err = mdsc->mdsmap_err;
2776                         dout("do_request mdsmap err %d\n", err);
2777                         goto finish;
2778                 }
2779                 if (mdsc->mdsmap->m_epoch == 0) {
2780                         dout("do_request no mdsmap, waiting for map\n");
2781                         list_add(&req->r_wait, &mdsc->waiting_for_map);
2782                         return;
2783                 }
2784                 if (!(mdsc->fsc->mount_options->flags &
2785                       CEPH_MOUNT_OPT_MOUNTWAIT) &&
2786                     !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2787                         err = -EHOSTUNREACH;
2788                         goto finish;
2789                 }
2790         }
2791
2792         put_request_session(req);
2793
2794         mds = __choose_mds(mdsc, req, &random);
2795         if (mds < 0 ||
2796             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2797                 if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags)) {
2798                         err = -EJUKEBOX;
2799                         goto finish;
2800                 }
2801                 dout("do_request no mds or not active, waiting for map\n");
2802                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2803                 return;
2804         }
2805
2806         /* get, open session */
2807         session = __ceph_lookup_mds_session(mdsc, mds);
2808         if (!session) {
2809                 session = register_session(mdsc, mds);
2810                 if (IS_ERR(session)) {
2811                         err = PTR_ERR(session);
2812                         goto finish;
2813                 }
2814         }
2815         req->r_session = ceph_get_mds_session(session);
2816
2817         dout("do_request mds%d session %p state %s\n", mds, session,
2818              ceph_session_state_name(session->s_state));
2819         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2820             session->s_state != CEPH_MDS_SESSION_HUNG) {
2821                 if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2822                         err = -EACCES;
2823                         goto out_session;
2824                 }
2825                 /*
2826                  * We cannot queue async requests since the caps and delegated
2827                  * inodes are bound to the session. Just return -EJUKEBOX and
2828                  * let the caller retry a sync request in that case.
2829                  */
2830                 if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags)) {
2831                         err = -EJUKEBOX;
2832                         goto out_session;
2833                 }
2834                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2835                     session->s_state == CEPH_MDS_SESSION_CLOSING) {
2836                         err = __open_session(mdsc, session);
2837                         if (err)
2838                                 goto out_session;
2839                         /* retry the same mds later */
2840                         if (random)
2841                                 req->r_resend_mds = mds;
2842                 }
2843                 list_add(&req->r_wait, &session->s_waiting);
2844                 goto out_session;
2845         }
2846
2847         /* send request */
2848         req->r_resend_mds = -1;   /* forget any previous mds hint */
2849
2850         if (req->r_request_started == 0)   /* note request start time */
2851                 req->r_request_started = jiffies;
2852
2853         err = __send_request(mdsc, session, req, false);
2854
2855 out_session:
2856         ceph_put_mds_session(session);
2857 finish:
2858         if (err) {
2859                 dout("__do_request early error %d\n", err);
2860                 req->r_err = err;
2861                 complete_request(mdsc, req);
2862                 __unregister_request(mdsc, req);
2863         }
2864         return;
2865 }
2866
2867 /*
2868  * called under mdsc->mutex
2869  */
2870 static void __wake_requests(struct ceph_mds_client *mdsc,
2871                             struct list_head *head)
2872 {
2873         struct ceph_mds_request *req;
2874         LIST_HEAD(tmp_list);
2875
2876         list_splice_init(head, &tmp_list);
2877
2878         while (!list_empty(&tmp_list)) {
2879                 req = list_entry(tmp_list.next,
2880                                  struct ceph_mds_request, r_wait);
2881                 list_del_init(&req->r_wait);
2882                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2883                 __do_request(mdsc, req);
2884         }
2885 }
2886
2887 /*
2888  * Wake up threads with requests pending for @mds, so that they can
2889  * resubmit their requests to a possibly different mds.
2890  */
2891 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2892 {
2893         struct ceph_mds_request *req;
2894         struct rb_node *p = rb_first(&mdsc->request_tree);
2895
2896         dout("kick_requests mds%d\n", mds);
2897         while (p) {
2898                 req = rb_entry(p, struct ceph_mds_request, r_node);
2899                 p = rb_next(p);
2900                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2901                         continue;
2902                 if (req->r_attempts > 0)
2903                         continue; /* only new requests */
2904                 if (req->r_session &&
2905                     req->r_session->s_mds == mds) {
2906                         dout(" kicking tid %llu\n", req->r_tid);
2907                         list_del_init(&req->r_wait);
2908                         __do_request(mdsc, req);
2909                 }
2910         }
2911 }
2912
2913 int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
2914                               struct ceph_mds_request *req)
2915 {
2916         int err = 0;
2917
2918         /* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
2919         if (req->r_inode)
2920                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2921         if (req->r_parent) {
2922                 struct ceph_inode_info *ci = ceph_inode(req->r_parent);
2923                 int fmode = (req->r_op & CEPH_MDS_OP_WRITE) ?
2924                             CEPH_FILE_MODE_WR : CEPH_FILE_MODE_RD;
2925                 spin_lock(&ci->i_ceph_lock);
2926                 ceph_take_cap_refs(ci, CEPH_CAP_PIN, false);
2927                 __ceph_touch_fmode(ci, mdsc, fmode);
2928                 spin_unlock(&ci->i_ceph_lock);
2929                 ihold(req->r_parent);
2930         }
2931         if (req->r_old_dentry_dir)
2932                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2933                                   CEPH_CAP_PIN);
2934
2935         if (req->r_inode) {
2936                 err = ceph_wait_on_async_create(req->r_inode);
2937                 if (err) {
2938                         dout("%s: wait for async create returned: %d\n",
2939                              __func__, err);
2940                         return err;
2941                 }
2942         }
2943
2944         if (!err && req->r_old_inode) {
2945                 err = ceph_wait_on_async_create(req->r_old_inode);
2946                 if (err) {
2947                         dout("%s: wait for async create returned: %d\n",
2948                              __func__, err);
2949                         return err;
2950                 }
2951         }
2952
2953         dout("submit_request on %p for inode %p\n", req, dir);
2954         mutex_lock(&mdsc->mutex);
2955         __register_request(mdsc, req, dir);
2956         __do_request(mdsc, req);
2957         err = req->r_err;
2958         mutex_unlock(&mdsc->mutex);
2959         return err;
2960 }
2961
2962 static int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
2963                                   struct ceph_mds_request *req)
2964 {
2965         int err;
2966
2967         /* wait */
2968         dout("do_request waiting\n");
2969         if (!req->r_timeout && req->r_wait_for_completion) {
2970                 err = req->r_wait_for_completion(mdsc, req);
2971         } else {
2972                 long timeleft = wait_for_completion_killable_timeout(
2973                                         &req->r_completion,
2974                                         ceph_timeout_jiffies(req->r_timeout));
2975                 if (timeleft > 0)
2976                         err = 0;
2977                 else if (!timeleft)
2978                         err = -ETIMEDOUT;  /* timed out */
2979                 else
2980                         err = timeleft;  /* killed */
2981         }
2982         dout("do_request waited, got %d\n", err);
2983         mutex_lock(&mdsc->mutex);
2984
2985         /* only abort if we didn't race with a real reply */
2986         if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2987                 err = le32_to_cpu(req->r_reply_info.head->result);
2988         } else if (err < 0) {
2989                 dout("aborted request %lld with %d\n", req->r_tid, err);
2990
2991                 /*
2992                  * ensure we aren't running concurrently with
2993                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2994                  * rely on locks (dir mutex) held by our caller.
2995                  */
2996                 mutex_lock(&req->r_fill_mutex);
2997                 req->r_err = err;
2998                 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
2999                 mutex_unlock(&req->r_fill_mutex);
3000
3001                 if (req->r_parent &&
3002                     (req->r_op & CEPH_MDS_OP_WRITE))
3003                         ceph_invalidate_dir_request(req);
3004         } else {
3005                 err = req->r_err;
3006         }
3007
3008         mutex_unlock(&mdsc->mutex);
3009         return err;
3010 }
3011
3012 /*
3013  * Synchrously perform an mds request.  Take care of all of the
3014  * session setup, forwarding, retry details.
3015  */
3016 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
3017                          struct inode *dir,
3018                          struct ceph_mds_request *req)
3019 {
3020         int err;
3021
3022         dout("do_request on %p\n", req);
3023
3024         /* issue */
3025         err = ceph_mdsc_submit_request(mdsc, dir, req);
3026         if (!err)
3027                 err = ceph_mdsc_wait_request(mdsc, req);
3028         dout("do_request %p done, result %d\n", req, err);
3029         return err;
3030 }
3031
3032 /*
3033  * Invalidate dir's completeness, dentry lease state on an aborted MDS
3034  * namespace request.
3035  */
3036 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
3037 {
3038         struct inode *dir = req->r_parent;
3039         struct inode *old_dir = req->r_old_dentry_dir;
3040
3041         dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
3042
3043         ceph_dir_clear_complete(dir);
3044         if (old_dir)
3045                 ceph_dir_clear_complete(old_dir);
3046         if (req->r_dentry)
3047                 ceph_invalidate_dentry_lease(req->r_dentry);
3048         if (req->r_old_dentry)
3049                 ceph_invalidate_dentry_lease(req->r_old_dentry);
3050 }
3051
3052 /*
3053  * Handle mds reply.
3054  *
3055  * We take the session mutex and parse and process the reply immediately.
3056  * This preserves the logical ordering of replies, capabilities, etc., sent
3057  * by the MDS as they are applied to our local cache.
3058  */
3059 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
3060 {
3061         struct ceph_mds_client *mdsc = session->s_mdsc;
3062         struct ceph_mds_request *req;
3063         struct ceph_mds_reply_head *head = msg->front.iov_base;
3064         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
3065         struct ceph_snap_realm *realm;
3066         u64 tid;
3067         int err, result;
3068         int mds = session->s_mds;
3069
3070         if (msg->front.iov_len < sizeof(*head)) {
3071                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
3072                 ceph_msg_dump(msg);
3073                 return;
3074         }
3075
3076         /* get request, session */
3077         tid = le64_to_cpu(msg->hdr.tid);
3078         mutex_lock(&mdsc->mutex);
3079         req = lookup_get_request(mdsc, tid);
3080         if (!req) {
3081                 dout("handle_reply on unknown tid %llu\n", tid);
3082                 mutex_unlock(&mdsc->mutex);
3083                 return;
3084         }
3085         dout("handle_reply %p\n", req);
3086
3087         /* correct session? */
3088         if (req->r_session != session) {
3089                 pr_err("mdsc_handle_reply got %llu on session mds%d"
3090                        " not mds%d\n", tid, session->s_mds,
3091                        req->r_session ? req->r_session->s_mds : -1);
3092                 mutex_unlock(&mdsc->mutex);
3093                 goto out;
3094         }
3095
3096         /* dup? */
3097         if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
3098             (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
3099                 pr_warn("got a dup %s reply on %llu from mds%d\n",
3100                            head->safe ? "safe" : "unsafe", tid, mds);
3101                 mutex_unlock(&mdsc->mutex);
3102                 goto out;
3103         }
3104         if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
3105                 pr_warn("got unsafe after safe on %llu from mds%d\n",
3106                            tid, mds);
3107                 mutex_unlock(&mdsc->mutex);
3108                 goto out;
3109         }
3110
3111         result = le32_to_cpu(head->result);
3112
3113         /*
3114          * Handle an ESTALE
3115          * if we're not talking to the authority, send to them
3116          * if the authority has changed while we weren't looking,
3117          * send to new authority
3118          * Otherwise we just have to return an ESTALE
3119          */
3120         if (result == -ESTALE) {
3121                 dout("got ESTALE on request %llu\n", req->r_tid);
3122                 req->r_resend_mds = -1;
3123                 if (req->r_direct_mode != USE_AUTH_MDS) {
3124                         dout("not using auth, setting for that now\n");
3125                         req->r_direct_mode = USE_AUTH_MDS;
3126                         __do_request(mdsc, req);
3127                         mutex_unlock(&mdsc->mutex);
3128                         goto out;
3129                 } else  {
3130                         int mds = __choose_mds(mdsc, req, NULL);
3131                         if (mds >= 0 && mds != req->r_session->s_mds) {
3132                                 dout("but auth changed, so resending\n");
3133                                 __do_request(mdsc, req);
3134                                 mutex_unlock(&mdsc->mutex);
3135                                 goto out;
3136                         }
3137                 }
3138                 dout("have to return ESTALE on request %llu\n", req->r_tid);
3139         }
3140
3141
3142         if (head->safe) {
3143                 set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
3144                 __unregister_request(mdsc, req);
3145
3146                 /* last request during umount? */
3147                 if (mdsc->stopping && !__get_oldest_req(mdsc))
3148                         complete_all(&mdsc->safe_umount_waiters);
3149
3150                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
3151                         /*
3152                          * We already handled the unsafe response, now do the
3153                          * cleanup.  No need to examine the response; the MDS
3154                          * doesn't include any result info in the safe
3155                          * response.  And even if it did, there is nothing
3156                          * useful we could do with a revised return value.
3157                          */
3158                         dout("got safe reply %llu, mds%d\n", tid, mds);
3159
3160                         mutex_unlock(&mdsc->mutex);
3161                         goto out;
3162                 }
3163         } else {
3164                 set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
3165                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
3166         }
3167
3168         dout("handle_reply tid %lld result %d\n", tid, result);
3169         rinfo = &req->r_reply_info;
3170         if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
3171                 err = parse_reply_info(session, msg, rinfo, (u64)-1);
3172         else
3173                 err = parse_reply_info(session, msg, rinfo, session->s_con.peer_features);
3174         mutex_unlock(&mdsc->mutex);
3175
3176         mutex_lock(&session->s_mutex);
3177         if (err < 0) {
3178                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
3179                 ceph_msg_dump(msg);
3180                 goto out_err;
3181         }
3182
3183         /* snap trace */
3184         realm = NULL;
3185         if (rinfo->snapblob_len) {
3186                 down_write(&mdsc->snap_rwsem);
3187                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
3188                                 rinfo->snapblob + rinfo->snapblob_len,
3189                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
3190                                 &realm);
3191                 downgrade_write(&mdsc->snap_rwsem);
3192         } else {
3193                 down_read(&mdsc->snap_rwsem);
3194         }
3195
3196         /* insert trace into our cache */
3197         mutex_lock(&req->r_fill_mutex);
3198         current->journal_info = req;
3199         err = ceph_fill_trace(mdsc->fsc->sb, req);
3200         if (err == 0) {
3201                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
3202                                     req->r_op == CEPH_MDS_OP_LSSNAP))
3203                         ceph_readdir_prepopulate(req, req->r_session);
3204         }
3205         current->journal_info = NULL;
3206         mutex_unlock(&req->r_fill_mutex);
3207
3208         up_read(&mdsc->snap_rwsem);
3209         if (realm)
3210                 ceph_put_snap_realm(mdsc, realm);
3211
3212         if (err == 0) {
3213                 if (req->r_target_inode &&
3214                     test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
3215                         struct ceph_inode_info *ci =
3216                                 ceph_inode(req->r_target_inode);
3217                         spin_lock(&ci->i_unsafe_lock);
3218                         list_add_tail(&req->r_unsafe_target_item,
3219                                       &ci->i_unsafe_iops);
3220                         spin_unlock(&ci->i_unsafe_lock);
3221                 }
3222
3223                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
3224         }
3225 out_err:
3226         mutex_lock(&mdsc->mutex);
3227         if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3228                 if (err) {
3229                         req->r_err = err;
3230                 } else {
3231                         req->r_reply =  ceph_msg_get(msg);
3232                         set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
3233                 }
3234         } else {
3235                 dout("reply arrived after request %lld was aborted\n", tid);
3236         }
3237         mutex_unlock(&mdsc->mutex);
3238
3239         mutex_unlock(&session->s_mutex);
3240
3241         /* kick calling process */
3242         complete_request(mdsc, req);
3243
3244         ceph_update_metadata_latency(&mdsc->metric, req->r_start_latency,
3245                                      req->r_end_latency, err);
3246 out:
3247         ceph_mdsc_put_request(req);
3248         return;
3249 }
3250
3251
3252
3253 /*
3254  * handle mds notification that our request has been forwarded.
3255  */
3256 static void handle_forward(struct ceph_mds_client *mdsc,
3257                            struct ceph_mds_session *session,
3258                            struct ceph_msg *msg)
3259 {
3260         struct ceph_mds_request *req;
3261         u64 tid = le64_to_cpu(msg->hdr.tid);
3262         u32 next_mds;
3263         u32 fwd_seq;
3264         int err = -EINVAL;
3265         void *p = msg->front.iov_base;
3266         void *end = p + msg->front.iov_len;
3267
3268         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
3269         next_mds = ceph_decode_32(&p);
3270         fwd_seq = ceph_decode_32(&p);
3271
3272         mutex_lock(&mdsc->mutex);
3273         req = lookup_get_request(mdsc, tid);
3274         if (!req) {
3275                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
3276                 goto out;  /* dup reply? */
3277         }
3278
3279         if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3280                 dout("forward tid %llu aborted, unregistering\n", tid);
3281                 __unregister_request(mdsc, req);
3282         } else if (fwd_seq <= req->r_num_fwd) {
3283                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
3284                      tid, next_mds, req->r_num_fwd, fwd_seq);
3285         } else {
3286                 /* resend. forward race not possible; mds would drop */
3287                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
3288                 BUG_ON(req->r_err);
3289                 BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
3290                 req->r_attempts = 0;
3291                 req->r_num_fwd = fwd_seq;
3292                 req->r_resend_mds = next_mds;
3293                 put_request_session(req);
3294                 __do_request(mdsc, req);
3295         }
3296         ceph_mdsc_put_request(req);
3297 out:
3298         mutex_unlock(&mdsc->mutex);
3299         return;
3300
3301 bad:
3302         pr_err("mdsc_handle_forward decode error err=%d\n", err);
3303 }
3304
3305 static int __decode_session_metadata(void **p, void *end,
3306                                      bool *blocklisted)
3307 {
3308         /* map<string,string> */
3309         u32 n;
3310         bool err_str;
3311         ceph_decode_32_safe(p, end, n, bad);
3312         while (n-- > 0) {
3313                 u32 len;
3314                 ceph_decode_32_safe(p, end, len, bad);
3315                 ceph_decode_need(p, end, len, bad);
3316                 err_str = !strncmp(*p, "error_string", len);
3317                 *p += len;
3318                 ceph_decode_32_safe(p, end, len, bad);
3319                 ceph_decode_need(p, end, len, bad);
3320                 /*
3321                  * Match "blocklisted (blacklisted)" from newer MDSes,
3322                  * or "blacklisted" from older MDSes.
3323                  */
3324                 if (err_str && strnstr(*p, "blacklisted", len))
3325                         *blocklisted = true;
3326                 *p += len;
3327         }
3328         return 0;
3329 bad:
3330         return -1;
3331 }
3332
3333 /*
3334  * handle a mds session control message
3335  */
3336 static void handle_session(struct ceph_mds_session *session,
3337                            struct ceph_msg *msg)
3338 {
3339         struct ceph_mds_client *mdsc = session->s_mdsc;
3340         int mds = session->s_mds;
3341         int msg_version = le16_to_cpu(msg->hdr.version);
3342         void *p = msg->front.iov_base;
3343         void *end = p + msg->front.iov_len;
3344         struct ceph_mds_session_head *h;
3345         u32 op;
3346         u64 seq, features = 0;
3347         int wake = 0;
3348         bool blocklisted = false;
3349
3350         /* decode */
3351         ceph_decode_need(&p, end, sizeof(*h), bad);
3352         h = p;
3353         p += sizeof(*h);
3354
3355         op = le32_to_cpu(h->op);
3356         seq = le64_to_cpu(h->seq);
3357
3358         if (msg_version >= 3) {
3359                 u32 len;
3360                 /* version >= 2, metadata */
3361                 if (__decode_session_metadata(&p, end, &blocklisted) < 0)
3362                         goto bad;
3363                 /* version >= 3, feature bits */
3364                 ceph_decode_32_safe(&p, end, len, bad);
3365                 if (len) {
3366                         ceph_decode_64_safe(&p, end, features, bad);
3367                         p += len - sizeof(features);
3368                 }
3369         }
3370
3371         mutex_lock(&mdsc->mutex);
3372         if (op == CEPH_SESSION_CLOSE) {
3373                 ceph_get_mds_session(session);
3374                 __unregister_session(mdsc, session);
3375         }
3376         /* FIXME: this ttl calculation is generous */
3377         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
3378         mutex_unlock(&mdsc->mutex);
3379
3380         mutex_lock(&session->s_mutex);
3381
3382         dout("handle_session mds%d %s %p state %s seq %llu\n",
3383              mds, ceph_session_op_name(op), session,
3384              ceph_session_state_name(session->s_state), seq);
3385
3386         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
3387                 session->s_state = CEPH_MDS_SESSION_OPEN;
3388                 pr_info("mds%d came back\n", session->s_mds);
3389         }
3390
3391         switch (op) {
3392         case CEPH_SESSION_OPEN:
3393                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3394                         pr_info("mds%d reconnect success\n", session->s_mds);
3395                 session->s_state = CEPH_MDS_SESSION_OPEN;
3396                 session->s_features = features;
3397                 renewed_caps(mdsc, session, 0);
3398                 if (test_bit(CEPHFS_FEATURE_METRIC_COLLECT, &session->s_features))
3399                         metric_schedule_delayed(&mdsc->metric);
3400                 wake = 1;
3401                 if (mdsc->stopping)
3402                         __close_session(mdsc, session);
3403                 break;
3404
3405         case CEPH_SESSION_RENEWCAPS:
3406                 if (session->s_renew_seq == seq)
3407                         renewed_caps(mdsc, session, 1);
3408                 break;
3409
3410         case CEPH_SESSION_CLOSE:
3411                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3412                         pr_info("mds%d reconnect denied\n", session->s_mds);
3413                 session->s_state = CEPH_MDS_SESSION_CLOSED;
3414                 cleanup_session_requests(mdsc, session);
3415                 remove_session_caps(session);
3416                 wake = 2; /* for good measure */
3417                 wake_up_all(&mdsc->session_close_wq);
3418                 break;
3419
3420         case CEPH_SESSION_STALE:
3421                 pr_info("mds%d caps went stale, renewing\n",
3422                         session->s_mds);
3423                 spin_lock(&session->s_gen_ttl_lock);
3424                 session->s_cap_gen++;
3425                 session->s_cap_ttl = jiffies - 1;
3426                 spin_unlock(&session->s_gen_ttl_lock);
3427                 send_renew_caps(mdsc, session);
3428                 break;
3429
3430         case CEPH_SESSION_RECALL_STATE:
3431                 ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
3432                 break;
3433
3434         case CEPH_SESSION_FLUSHMSG:
3435                 send_flushmsg_ack(mdsc, session, seq);
3436                 break;
3437
3438         case CEPH_SESSION_FORCE_RO:
3439                 dout("force_session_readonly %p\n", session);
3440                 spin_lock(&session->s_cap_lock);
3441                 session->s_readonly = true;
3442                 spin_unlock(&session->s_cap_lock);
3443                 wake_up_session_caps(session, FORCE_RO);
3444                 break;
3445
3446         case CEPH_SESSION_REJECT:
3447                 WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
3448                 pr_info("mds%d rejected session\n", session->s_mds);
3449                 session->s_state = CEPH_MDS_SESSION_REJECTED;
3450                 cleanup_session_requests(mdsc, session);
3451                 remove_session_caps(session);
3452                 if (blocklisted)
3453                         mdsc->fsc->blocklisted = true;
3454                 wake = 2; /* for good measure */
3455                 break;
3456
3457         default:
3458                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
3459                 WARN_ON(1);
3460         }
3461
3462         mutex_unlock(&session->s_mutex);
3463         if (wake) {
3464                 mutex_lock(&mdsc->mutex);
3465                 __wake_requests(mdsc, &session->s_waiting);
3466                 if (wake == 2)
3467                         kick_requests(mdsc, mds);
3468                 mutex_unlock(&mdsc->mutex);
3469         }
3470         if (op == CEPH_SESSION_CLOSE)
3471                 ceph_put_mds_session(session);
3472         return;
3473
3474 bad:
3475         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
3476                (int)msg->front.iov_len);
3477         ceph_msg_dump(msg);
3478         return;
3479 }
3480
3481 void ceph_mdsc_release_dir_caps(struct ceph_mds_request *req)
3482 {
3483         int dcaps;
3484
3485         dcaps = xchg(&req->r_dir_caps, 0);
3486         if (dcaps) {
3487                 dout("releasing r_dir_caps=%s\n", ceph_cap_string(dcaps));
3488                 ceph_put_cap_refs(ceph_inode(req->r_parent), dcaps);
3489         }
3490 }
3491
3492 void ceph_mdsc_release_dir_caps_no_check(struct ceph_mds_request *req)
3493 {
3494         int dcaps;
3495
3496         dcaps = xchg(&req->r_dir_caps, 0);
3497         if (dcaps) {
3498                 dout("releasing r_dir_caps=%s\n", ceph_cap_string(dcaps));
3499                 ceph_put_cap_refs_no_check_caps(ceph_inode(req->r_parent),
3500                                                 dcaps);
3501         }
3502 }
3503
3504 /*
3505  * called under session->mutex.
3506  */
3507 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
3508                                    struct ceph_mds_session *session)
3509 {
3510         struct ceph_mds_request *req, *nreq;
3511         struct rb_node *p;
3512
3513         dout("replay_unsafe_requests mds%d\n", session->s_mds);
3514
3515         mutex_lock(&mdsc->mutex);
3516         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item)
3517                 __send_request(mdsc, session, req, true);
3518
3519         /*
3520          * also re-send old requests when MDS enters reconnect stage. So that MDS
3521          * can process completed request in clientreplay stage.
3522          */
3523         p = rb_first(&mdsc->request_tree);
3524         while (p) {
3525                 req = rb_entry(p, struct ceph_mds_request, r_node);
3526                 p = rb_next(p);
3527                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3528                         continue;
3529                 if (req->r_attempts == 0)
3530                         continue; /* only old requests */
3531                 if (!req->r_session)
3532                         continue;
3533                 if (req->r_session->s_mds != session->s_mds)
3534                         continue;
3535
3536                 ceph_mdsc_release_dir_caps_no_check(req);
3537
3538                 __send_request(mdsc, session, req, true);
3539         }
3540         mutex_unlock(&mdsc->mutex);
3541 }
3542
3543 static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
3544 {
3545         struct ceph_msg *reply;
3546         struct ceph_pagelist *_pagelist;
3547         struct page *page;
3548         __le32 *addr;
3549         int err = -ENOMEM;
3550
3551         if (!recon_state->allow_multi)
3552                 return -ENOSPC;
3553
3554         /* can't handle message that contains both caps and realm */
3555         BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3556
3557         /* pre-allocate new pagelist */
3558         _pagelist = ceph_pagelist_alloc(GFP_NOFS);
3559         if (!_pagelist)
3560                 return -ENOMEM;
3561
3562         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3563         if (!reply)
3564                 goto fail_msg;
3565
3566         /* placeholder for nr_caps */
3567         err = ceph_pagelist_encode_32(_pagelist, 0);
3568         if (err < 0)
3569                 goto fail;
3570
3571         if (recon_state->nr_caps) {
3572                 /* currently encoding caps */
3573                 err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3574                 if (err)
3575                         goto fail;
3576         } else {
3577                 /* placeholder for nr_realms (currently encoding relams) */
3578                 err = ceph_pagelist_encode_32(_pagelist, 0);
3579                 if (err < 0)
3580                         goto fail;
3581         }
3582
3583         err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3584         if (err)
3585                 goto fail;
3586
3587         page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3588         addr = kmap_atomic(page);
3589         if (recon_state->nr_caps) {
3590                 /* currently encoding caps */
3591                 *addr = cpu_to_le32(recon_state->nr_caps);
3592         } else {
3593                 /* currently encoding relams */
3594                 *(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3595         }
3596         kunmap_atomic(addr);
3597
3598         reply->hdr.version = cpu_to_le16(5);
3599         reply->hdr.compat_version = cpu_to_le16(4);
3600
3601         reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3602         ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3603
3604         ceph_con_send(&recon_state->session->s_con, reply);
3605         ceph_pagelist_release(recon_state->pagelist);
3606
3607         recon_state->pagelist = _pagelist;
3608         recon_state->nr_caps = 0;
3609         recon_state->nr_realms = 0;
3610         recon_state->msg_version = 5;
3611         return 0;
3612 fail:
3613         ceph_msg_put(reply);
3614 fail_msg:
3615         ceph_pagelist_release(_pagelist);
3616         return err;
3617 }
3618
3619 static struct dentry* d_find_primary(struct inode *inode)
3620 {
3621         struct dentry *alias, *dn = NULL;
3622
3623         if (hlist_empty(&inode->i_dentry))
3624                 return NULL;
3625
3626         spin_lock(&inode->i_lock);
3627         if (hlist_empty(&inode->i_dentry))
3628                 goto out_unlock;
3629
3630         if (S_ISDIR(inode->i_mode)) {
3631                 alias = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
3632                 if (!IS_ROOT(alias))
3633                         dn = dget(alias);
3634                 goto out_unlock;
3635         }
3636
3637         hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
3638                 spin_lock(&alias->d_lock);
3639                 if (!d_unhashed(alias) &&
3640                     (ceph_dentry(alias)->flags & CEPH_DENTRY_PRIMARY_LINK)) {
3641                         dn = dget_dlock(alias);
3642                 }
3643                 spin_unlock(&alias->d_lock);
3644                 if (dn)
3645                         break;
3646         }
3647 out_unlock:
3648         spin_unlock(&inode->i_lock);
3649         return dn;
3650 }
3651
3652 /*
3653  * Encode information about a cap for a reconnect with the MDS.
3654  */
3655 static int reconnect_caps_cb(struct inode *inode, struct ceph_cap *cap,
3656                           void *arg)
3657 {
3658         union {
3659                 struct ceph_mds_cap_reconnect v2;
3660                 struct ceph_mds_cap_reconnect_v1 v1;
3661         } rec;
3662         struct ceph_inode_info *ci = cap->ci;
3663         struct ceph_reconnect_state *recon_state = arg;
3664         struct ceph_pagelist *pagelist = recon_state->pagelist;
3665         struct dentry *dentry;
3666         char *path;
3667         int pathlen, err;
3668         u64 pathbase;
3669         u64 snap_follows;
3670
3671         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3672              inode, ceph_vinop(inode), cap, cap->cap_id,
3673              ceph_cap_string(cap->issued));
3674
3675         dentry = d_find_primary(inode);
3676         if (dentry) {
3677                 /* set pathbase to parent dir when msg_version >= 2 */
3678                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase,
3679                                             recon_state->msg_version >= 2);
3680                 dput(dentry);
3681                 if (IS_ERR(path)) {
3682                         err = PTR_ERR(path);
3683                         goto out_err;
3684                 }
3685         } else {
3686                 path = NULL;
3687                 pathlen = 0;
3688                 pathbase = 0;
3689         }
3690
3691         spin_lock(&ci->i_ceph_lock);
3692         cap->seq = 0;        /* reset cap seq */
3693         cap->issue_seq = 0;  /* and issue_seq */
3694         cap->mseq = 0;       /* and migrate_seq */
3695         cap->cap_gen = cap->session->s_cap_gen;
3696
3697         /* These are lost when the session goes away */
3698         if (S_ISDIR(inode->i_mode)) {
3699                 if (cap->issued & CEPH_CAP_DIR_CREATE) {
3700                         ceph_put_string(rcu_dereference_raw(ci->i_cached_layout.pool_ns));
3701                         memset(&ci->i_cached_layout, 0, sizeof(ci->i_cached_layout));
3702                 }
3703                 cap->issued &= ~CEPH_CAP_ANY_DIR_OPS;
3704         }
3705
3706         if (recon_state->msg_version >= 2) {
3707                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3708                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3709                 rec.v2.issued = cpu_to_le32(cap->issued);
3710                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3711                 rec.v2.pathbase = cpu_to_le64(pathbase);
3712                 rec.v2.flock_len = (__force __le32)
3713                         ((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3714         } else {
3715                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3716                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3717                 rec.v1.issued = cpu_to_le32(cap->issued);
3718                 rec.v1.size = cpu_to_le64(inode->i_size);
3719                 ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3720                 ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3721                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3722                 rec.v1.pathbase = cpu_to_le64(pathbase);
3723         }
3724
3725         if (list_empty(&ci->i_cap_snaps)) {
3726                 snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3727         } else {
3728                 struct ceph_cap_snap *capsnap =
3729                         list_first_entry(&ci->i_cap_snaps,
3730                                          struct ceph_cap_snap, ci_item);
3731                 snap_follows = capsnap->follows;
3732         }
3733         spin_unlock(&ci->i_ceph_lock);
3734
3735         if (recon_state->msg_version >= 2) {
3736                 int num_fcntl_locks, num_flock_locks;
3737                 struct ceph_filelock *flocks = NULL;
3738                 size_t struct_len, total_len = sizeof(u64);
3739                 u8 struct_v = 0;
3740
3741 encode_again:
3742                 if (rec.v2.flock_len) {
3743                         ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
3744                 } else {
3745                         num_fcntl_locks = 0;
3746                         num_flock_locks = 0;
3747                 }
3748                 if (num_fcntl_locks + num_flock_locks > 0) {
3749                         flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
3750                                                sizeof(struct ceph_filelock),
3751                                                GFP_NOFS);
3752                         if (!flocks) {
3753                                 err = -ENOMEM;
3754                                 goto out_err;
3755                         }
3756                         err = ceph_encode_locks_to_buffer(inode, flocks,
3757                                                           num_fcntl_locks,
3758                                                           num_flock_locks);
3759                         if (err) {
3760                                 kfree(flocks);
3761                                 flocks = NULL;
3762                                 if (err == -ENOSPC)
3763                                         goto encode_again;
3764                                 goto out_err;
3765                         }
3766                 } else {
3767                         kfree(flocks);
3768                         flocks = NULL;
3769                 }
3770
3771                 if (recon_state->msg_version >= 3) {
3772                         /* version, compat_version and struct_len */
3773                         total_len += 2 * sizeof(u8) + sizeof(u32);
3774                         struct_v = 2;
3775                 }
3776                 /*
3777                  * number of encoded locks is stable, so copy to pagelist
3778                  */
3779                 struct_len = 2 * sizeof(u32) +
3780                             (num_fcntl_locks + num_flock_locks) *
3781                             sizeof(struct ceph_filelock);
3782                 rec.v2.flock_len = cpu_to_le32(struct_len);
3783
3784                 struct_len += sizeof(u32) + pathlen + sizeof(rec.v2);
3785
3786                 if (struct_v >= 2)
3787                         struct_len += sizeof(u64); /* snap_follows */
3788
3789                 total_len += struct_len;
3790
3791                 if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
3792                         err = send_reconnect_partial(recon_state);
3793                         if (err)
3794                                 goto out_freeflocks;
3795                         pagelist = recon_state->pagelist;
3796                 }
3797
3798                 err = ceph_pagelist_reserve(pagelist, total_len);
3799                 if (err)
3800                         goto out_freeflocks;
3801
3802                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3803                 if (recon_state->msg_version >= 3) {
3804                         ceph_pagelist_encode_8(pagelist, struct_v);
3805                         ceph_pagelist_encode_8(pagelist, 1);
3806                         ceph_pagelist_encode_32(pagelist, struct_len);
3807                 }
3808                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3809                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
3810                 ceph_locks_to_pagelist(flocks, pagelist,
3811                                        num_fcntl_locks, num_flock_locks);
3812                 if (struct_v >= 2)
3813                         ceph_pagelist_encode_64(pagelist, snap_follows);
3814 out_freeflocks:
3815                 kfree(flocks);
3816         } else {
3817                 err = ceph_pagelist_reserve(pagelist,
3818                                             sizeof(u64) + sizeof(u32) +
3819                                             pathlen + sizeof(rec.v1));
3820                 if (err)
3821                         goto out_err;
3822
3823                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3824                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3825                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
3826         }
3827
3828 out_err:
3829         ceph_mdsc_free_path(path, pathlen);
3830         if (!err)
3831                 recon_state->nr_caps++;
3832         return err;
3833 }
3834
3835 static int encode_snap_realms(struct ceph_mds_client *mdsc,
3836                               struct ceph_reconnect_state *recon_state)
3837 {
3838         struct rb_node *p;
3839         struct ceph_pagelist *pagelist = recon_state->pagelist;
3840         int err = 0;
3841
3842         if (recon_state->msg_version >= 4) {
3843                 err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
3844                 if (err < 0)
3845                         goto fail;
3846         }
3847
3848         /*
3849          * snaprealms.  we provide mds with the ino, seq (version), and
3850          * parent for all of our realms.  If the mds has any newer info,
3851          * it will tell us.
3852          */
3853         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3854                 struct ceph_snap_realm *realm =
3855                        rb_entry(p, struct ceph_snap_realm, node);
3856                 struct ceph_mds_snaprealm_reconnect sr_rec;
3857
3858                 if (recon_state->msg_version >= 4) {
3859                         size_t need = sizeof(u8) * 2 + sizeof(u32) +
3860                                       sizeof(sr_rec);
3861
3862                         if (pagelist->length + need > RECONNECT_MAX_SIZE) {
3863                                 err = send_reconnect_partial(recon_state);
3864                                 if (err)
3865                                         goto fail;
3866                                 pagelist = recon_state->pagelist;
3867                         }
3868
3869                         err = ceph_pagelist_reserve(pagelist, need);
3870                         if (err)
3871                                 goto fail;
3872
3873                         ceph_pagelist_encode_8(pagelist, 1);
3874                         ceph_pagelist_encode_8(pagelist, 1);
3875                         ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
3876                 }
3877
3878                 dout(" adding snap realm %llx seq %lld parent %llx\n",
3879                      realm->ino, realm->seq, realm->parent_ino);
3880                 sr_rec.ino = cpu_to_le64(realm->ino);
3881                 sr_rec.seq = cpu_to_le64(realm->seq);
3882                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
3883
3884                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3885                 if (err)
3886                         goto fail;
3887
3888                 recon_state->nr_realms++;
3889         }
3890 fail:
3891         return err;
3892 }
3893
3894
3895 /*
3896  * If an MDS fails and recovers, clients need to reconnect in order to
3897  * reestablish shared state.  This includes all caps issued through
3898  * this session _and_ the snap_realm hierarchy.  Because it's not
3899  * clear which snap realms the mds cares about, we send everything we
3900  * know about.. that ensures we'll then get any new info the
3901  * recovering MDS might have.
3902  *
3903  * This is a relatively heavyweight operation, but it's rare.
3904  */
3905 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
3906                                struct ceph_mds_session *session)
3907 {
3908         struct ceph_msg *reply;
3909         int mds = session->s_mds;
3910         int err = -ENOMEM;
3911         struct ceph_reconnect_state recon_state = {
3912                 .session = session,
3913         };
3914         LIST_HEAD(dispose);
3915
3916         pr_info("mds%d reconnect start\n", mds);
3917
3918         recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
3919         if (!recon_state.pagelist)
3920                 goto fail_nopagelist;
3921
3922         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3923         if (!reply)
3924                 goto fail_nomsg;
3925
3926         xa_destroy(&session->s_delegated_inos);
3927
3928         mutex_lock(&session->s_mutex);
3929         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
3930         session->s_seq = 0;
3931
3932         dout("session %p state %s\n", session,
3933              ceph_session_state_name(session->s_state));
3934
3935         spin_lock(&session->s_gen_ttl_lock);
3936         session->s_cap_gen++;
3937         spin_unlock(&session->s_gen_ttl_lock);
3938
3939         spin_lock(&session->s_cap_lock);
3940         /* don't know if session is readonly */
3941         session->s_readonly = 0;
3942         /*
3943          * notify __ceph_remove_cap() that we are composing cap reconnect.
3944          * If a cap get released before being added to the cap reconnect,
3945          * __ceph_remove_cap() should skip queuing cap release.
3946          */
3947         session->s_cap_reconnect = 1;
3948         /* drop old cap expires; we're about to reestablish that state */
3949         detach_cap_releases(session, &dispose);
3950         spin_unlock(&session->s_cap_lock);
3951         dispose_cap_releases(mdsc, &dispose);
3952
3953         /* trim unused caps to reduce MDS's cache rejoin time */
3954         if (mdsc->fsc->sb->s_root)
3955                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
3956
3957         ceph_con_close(&session->s_con);
3958         ceph_con_open(&session->s_con,
3959                       CEPH_ENTITY_TYPE_MDS, mds,
3960                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
3961
3962         /* replay unsafe requests */
3963         replay_unsafe_requests(mdsc, session);
3964
3965         ceph_early_kick_flushing_caps(mdsc, session);
3966
3967         down_read(&mdsc->snap_rwsem);
3968
3969         /* placeholder for nr_caps */
3970         err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
3971         if (err)
3972                 goto fail;
3973
3974         if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
3975                 recon_state.msg_version = 3;
3976                 recon_state.allow_multi = true;
3977         } else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
3978                 recon_state.msg_version = 3;
3979         } else {
3980                 recon_state.msg_version = 2;
3981         }
3982         /* trsaverse this session's caps */
3983         err = ceph_iterate_session_caps(session, reconnect_caps_cb, &recon_state);
3984
3985         spin_lock(&session->s_cap_lock);
3986         session->s_cap_reconnect = 0;
3987         spin_unlock(&session->s_cap_lock);
3988
3989         if (err < 0)
3990                 goto fail;
3991
3992         /* check if all realms can be encoded into current message */
3993         if (mdsc->num_snap_realms) {
3994                 size_t total_len =
3995                         recon_state.pagelist->length +
3996                         mdsc->num_snap_realms *
3997                         sizeof(struct ceph_mds_snaprealm_reconnect);
3998                 if (recon_state.msg_version >= 4) {
3999                         /* number of realms */
4000                         total_len += sizeof(u32);
4001                         /* version, compat_version and struct_len */
4002                         total_len += mdsc->num_snap_realms *
4003                                      (2 * sizeof(u8) + sizeof(u32));
4004                 }
4005                 if (total_len > RECONNECT_MAX_SIZE) {
4006                         if (!recon_state.allow_multi) {
4007                                 err = -ENOSPC;
4008                                 goto fail;
4009                         }
4010                         if (recon_state.nr_caps) {
4011                                 err = send_reconnect_partial(&recon_state);
4012                                 if (err)
4013                                         goto fail;
4014                         }
4015                         recon_state.msg_version = 5;
4016                 }
4017         }
4018
4019         err = encode_snap_realms(mdsc, &recon_state);
4020         if (err < 0)
4021                 goto fail;
4022
4023         if (recon_state.msg_version >= 5) {
4024                 err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
4025                 if (err < 0)
4026                         goto fail;
4027         }
4028
4029         if (recon_state.nr_caps || recon_state.nr_realms) {
4030                 struct page *page =
4031                         list_first_entry(&recon_state.pagelist->head,
4032                                         struct page, lru);
4033                 __le32 *addr = kmap_atomic(page);
4034                 if (recon_state.nr_caps) {
4035                         WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
4036                         *addr = cpu_to_le32(recon_state.nr_caps);
4037                 } else if (recon_state.msg_version >= 4) {
4038                         *(addr + 1) = cpu_to_le32(recon_state.nr_realms);
4039                 }
4040                 kunmap_atomic(addr);
4041         }
4042
4043         reply->hdr.version = cpu_to_le16(recon_state.msg_version);
4044         if (recon_state.msg_version >= 4)
4045                 reply->hdr.compat_version = cpu_to_le16(4);
4046
4047         reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
4048         ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
4049
4050         ceph_con_send(&session->s_con, reply);
4051
4052         mutex_unlock(&session->s_mutex);
4053
4054         mutex_lock(&mdsc->mutex);
4055         __wake_requests(mdsc, &session->s_waiting);
4056         mutex_unlock(&mdsc->mutex);
4057
4058         up_read(&mdsc->snap_rwsem);
4059         ceph_pagelist_release(recon_state.pagelist);
4060         return;
4061
4062 fail:
4063         ceph_msg_put(reply);
4064         up_read(&mdsc->snap_rwsem);
4065         mutex_unlock(&session->s_mutex);
4066 fail_nomsg:
4067         ceph_pagelist_release(recon_state.pagelist);
4068 fail_nopagelist:
4069         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
4070         return;
4071 }
4072
4073
4074 /*
4075  * compare old and new mdsmaps, kicking requests
4076  * and closing out old connections as necessary
4077  *
4078  * called under mdsc->mutex.
4079  */
4080 static void check_new_map(struct ceph_mds_client *mdsc,
4081                           struct ceph_mdsmap *newmap,
4082                           struct ceph_mdsmap *oldmap)
4083 {
4084         int i;
4085         int oldstate, newstate;
4086         struct ceph_mds_session *s;
4087
4088         dout("check_new_map new %u old %u\n",
4089              newmap->m_epoch, oldmap->m_epoch);
4090
4091         for (i = 0; i < oldmap->possible_max_rank && i < mdsc->max_sessions; i++) {
4092                 if (!mdsc->sessions[i])
4093                         continue;
4094                 s = mdsc->sessions[i];
4095                 oldstate = ceph_mdsmap_get_state(oldmap, i);
4096                 newstate = ceph_mdsmap_get_state(newmap, i);
4097
4098                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
4099                      i, ceph_mds_state_name(oldstate),
4100                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
4101                      ceph_mds_state_name(newstate),
4102                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
4103                      ceph_session_state_name(s->s_state));
4104
4105                 if (i >= newmap->possible_max_rank) {
4106                         /* force close session for stopped mds */
4107                         ceph_get_mds_session(s);
4108                         __unregister_session(mdsc, s);
4109                         __wake_requests(mdsc, &s->s_waiting);
4110                         mutex_unlock(&mdsc->mutex);
4111
4112                         mutex_lock(&s->s_mutex);
4113                         cleanup_session_requests(mdsc, s);
4114                         remove_session_caps(s);
4115                         mutex_unlock(&s->s_mutex);
4116
4117                         ceph_put_mds_session(s);
4118
4119                         mutex_lock(&mdsc->mutex);
4120                         kick_requests(mdsc, i);
4121                         continue;
4122                 }
4123
4124                 if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
4125                            ceph_mdsmap_get_addr(newmap, i),
4126                            sizeof(struct ceph_entity_addr))) {
4127                         /* just close it */
4128                         mutex_unlock(&mdsc->mutex);
4129                         mutex_lock(&s->s_mutex);
4130                         mutex_lock(&mdsc->mutex);
4131                         ceph_con_close(&s->s_con);
4132                         mutex_unlock(&s->s_mutex);
4133                         s->s_state = CEPH_MDS_SESSION_RESTARTING;
4134                 } else if (oldstate == newstate) {
4135                         continue;  /* nothing new with this mds */
4136                 }
4137
4138                 /*
4139                  * send reconnect?
4140                  */
4141                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
4142                     newstate >= CEPH_MDS_STATE_RECONNECT) {
4143                         mutex_unlock(&mdsc->mutex);
4144                         send_mds_reconnect(mdsc, s);
4145                         mutex_lock(&mdsc->mutex);
4146                 }
4147
4148                 /*
4149                  * kick request on any mds that has gone active.
4150                  */
4151                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
4152                     newstate >= CEPH_MDS_STATE_ACTIVE) {
4153                         if (oldstate != CEPH_MDS_STATE_CREATING &&
4154                             oldstate != CEPH_MDS_STATE_STARTING)
4155                                 pr_info("mds%d recovery completed\n", s->s_mds);
4156                         kick_requests(mdsc, i);
4157                         mutex_unlock(&mdsc->mutex);
4158                         mutex_lock(&s->s_mutex);
4159                         mutex_lock(&mdsc->mutex);
4160                         ceph_kick_flushing_caps(mdsc, s);
4161                         mutex_unlock(&s->s_mutex);
4162                         wake_up_session_caps(s, RECONNECT);
4163                 }
4164         }
4165
4166         for (i = 0; i < newmap->possible_max_rank && i < mdsc->max_sessions; i++) {
4167                 s = mdsc->sessions[i];
4168                 if (!s)
4169                         continue;
4170                 if (!ceph_mdsmap_is_laggy(newmap, i))
4171                         continue;
4172                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4173                     s->s_state == CEPH_MDS_SESSION_HUNG ||
4174                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
4175                         dout(" connecting to export targets of laggy mds%d\n",
4176                              i);
4177                         __open_export_target_sessions(mdsc, s);
4178                 }
4179         }
4180 }
4181
4182
4183
4184 /*
4185  * leases
4186  */
4187
4188 /*
4189  * caller must hold session s_mutex, dentry->d_lock
4190  */
4191 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
4192 {
4193         struct ceph_dentry_info *di = ceph_dentry(dentry);
4194
4195         ceph_put_mds_session(di->lease_session);
4196         di->lease_session = NULL;
4197 }
4198
4199 static void handle_lease(struct ceph_mds_client *mdsc,
4200                          struct ceph_mds_session *session,
4201                          struct ceph_msg *msg)
4202 {
4203         struct super_block *sb = mdsc->fsc->sb;
4204         struct inode *inode;
4205         struct dentry *parent, *dentry;
4206         struct ceph_dentry_info *di;
4207         int mds = session->s_mds;
4208         struct ceph_mds_lease *h = msg->front.iov_base;
4209         u32 seq;
4210         struct ceph_vino vino;
4211         struct qstr dname;
4212         int release = 0;
4213
4214         dout("handle_lease from mds%d\n", mds);
4215
4216         /* decode */
4217         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
4218                 goto bad;
4219         vino.ino = le64_to_cpu(h->ino);
4220         vino.snap = CEPH_NOSNAP;
4221         seq = le32_to_cpu(h->seq);
4222         dname.len = get_unaligned_le32(h + 1);
4223         if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
4224                 goto bad;
4225         dname.name = (void *)(h + 1) + sizeof(u32);
4226
4227         /* lookup inode */
4228         inode = ceph_find_inode(sb, vino);
4229         dout("handle_lease %s, ino %llx %p %.*s\n",
4230              ceph_lease_op_name(h->action), vino.ino, inode,
4231              dname.len, dname.name);
4232
4233         mutex_lock(&session->s_mutex);
4234         inc_session_sequence(session);
4235
4236         if (!inode) {
4237                 dout("handle_lease no inode %llx\n", vino.ino);
4238                 goto release;
4239         }
4240
4241         /* dentry */
4242         parent = d_find_alias(inode);
4243         if (!parent) {
4244                 dout("no parent dentry on inode %p\n", inode);
4245                 WARN_ON(1);
4246                 goto release;  /* hrm... */
4247         }
4248         dname.hash = full_name_hash(parent, dname.name, dname.len);
4249         dentry = d_lookup(parent, &dname);
4250         dput(parent);
4251         if (!dentry)
4252                 goto release;
4253
4254         spin_lock(&dentry->d_lock);
4255         di = ceph_dentry(dentry);
4256         switch (h->action) {
4257         case CEPH_MDS_LEASE_REVOKE:
4258                 if (di->lease_session == session) {
4259                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
4260                                 h->seq = cpu_to_le32(di->lease_seq);
4261                         __ceph_mdsc_drop_dentry_lease(dentry);
4262                 }
4263                 release = 1;
4264                 break;
4265
4266         case CEPH_MDS_LEASE_RENEW:
4267                 if (di->lease_session == session &&
4268                     di->lease_gen == session->s_cap_gen &&
4269                     di->lease_renew_from &&
4270                     di->lease_renew_after == 0) {
4271                         unsigned long duration =
4272                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
4273
4274                         di->lease_seq = seq;
4275                         di->time = di->lease_renew_from + duration;
4276                         di->lease_renew_after = di->lease_renew_from +
4277                                 (duration >> 1);
4278                         di->lease_renew_from = 0;
4279                 }
4280                 break;
4281         }
4282         spin_unlock(&dentry->d_lock);
4283         dput(dentry);
4284
4285         if (!release)
4286                 goto out;
4287
4288 release:
4289         /* let's just reuse the same message */
4290         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
4291         ceph_msg_get(msg);
4292         ceph_con_send(&session->s_con, msg);
4293
4294 out:
4295         mutex_unlock(&session->s_mutex);
4296         /* avoid calling iput_final() in mds dispatch threads */
4297         ceph_async_iput(inode);
4298         return;
4299
4300 bad:
4301         pr_err("corrupt lease message\n");
4302         ceph_msg_dump(msg);
4303 }
4304
4305 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
4306                               struct dentry *dentry, char action,
4307                               u32 seq)
4308 {
4309         struct ceph_msg *msg;
4310         struct ceph_mds_lease *lease;
4311         struct inode *dir;
4312         int len = sizeof(*lease) + sizeof(u32) + NAME_MAX;
4313
4314         dout("lease_send_msg identry %p %s to mds%d\n",
4315              dentry, ceph_lease_op_name(action), session->s_mds);
4316
4317         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
4318         if (!msg)
4319                 return;
4320         lease = msg->front.iov_base;
4321         lease->action = action;
4322         lease->seq = cpu_to_le32(seq);
4323
4324         spin_lock(&dentry->d_lock);
4325         dir = d_inode(dentry->d_parent);
4326         lease->ino = cpu_to_le64(ceph_ino(dir));
4327         lease->first = lease->last = cpu_to_le64(ceph_snap(dir));
4328
4329         put_unaligned_le32(dentry->d_name.len, lease + 1);
4330         memcpy((void *)(lease + 1) + 4,
4331                dentry->d_name.name, dentry->d_name.len);
4332         spin_unlock(&dentry->d_lock);
4333         /*
4334          * if this is a preemptive lease RELEASE, no need to
4335          * flush request stream, since the actual request will
4336          * soon follow.
4337          */
4338         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
4339
4340         ceph_con_send(&session->s_con, msg);
4341 }
4342
4343 /*
4344  * lock unlock sessions, to wait ongoing session activities
4345  */
4346 static void lock_unlock_sessions(struct ceph_mds_client *mdsc)
4347 {
4348         int i;
4349
4350         mutex_lock(&mdsc->mutex);
4351         for (i = 0; i < mdsc->max_sessions; i++) {
4352                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4353                 if (!s)
4354                         continue;
4355                 mutex_unlock(&mdsc->mutex);
4356                 mutex_lock(&s->s_mutex);
4357                 mutex_unlock(&s->s_mutex);
4358                 ceph_put_mds_session(s);
4359                 mutex_lock(&mdsc->mutex);
4360         }
4361         mutex_unlock(&mdsc->mutex);
4362 }
4363
4364 static void maybe_recover_session(struct ceph_mds_client *mdsc)
4365 {
4366         struct ceph_fs_client *fsc = mdsc->fsc;
4367
4368         if (!ceph_test_mount_opt(fsc, CLEANRECOVER))
4369                 return;
4370
4371         if (READ_ONCE(fsc->mount_state) != CEPH_MOUNT_MOUNTED)
4372                 return;
4373
4374         if (!READ_ONCE(fsc->blocklisted))
4375                 return;
4376
4377         if (fsc->last_auto_reconnect &&
4378             time_before(jiffies, fsc->last_auto_reconnect + HZ * 60 * 30))
4379                 return;
4380
4381         pr_info("auto reconnect after blocklisted\n");
4382         fsc->last_auto_reconnect = jiffies;
4383         ceph_force_reconnect(fsc->sb);
4384 }
4385
4386 bool check_session_state(struct ceph_mds_session *s)
4387 {
4388         switch (s->s_state) {
4389         case CEPH_MDS_SESSION_OPEN:
4390                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
4391                         s->s_state = CEPH_MDS_SESSION_HUNG;
4392                         pr_info("mds%d hung\n", s->s_mds);
4393                 }
4394                 break;
4395         case CEPH_MDS_SESSION_CLOSING:
4396                 /* Should never reach this when we're unmounting */
4397                 WARN_ON_ONCE(true);
4398                 fallthrough;
4399         case CEPH_MDS_SESSION_NEW:
4400         case CEPH_MDS_SESSION_RESTARTING:
4401         case CEPH_MDS_SESSION_CLOSED:
4402         case CEPH_MDS_SESSION_REJECTED:
4403                 return false;
4404         }
4405
4406         return true;
4407 }
4408
4409 /*
4410  * If the sequence is incremented while we're waiting on a REQUEST_CLOSE reply,
4411  * then we need to retransmit that request.
4412  */
4413 void inc_session_sequence(struct ceph_mds_session *s)
4414 {
4415         lockdep_assert_held(&s->s_mutex);
4416
4417         s->s_seq++;
4418
4419         if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
4420                 int ret;
4421
4422                 dout("resending session close request for mds%d\n", s->s_mds);
4423                 ret = request_close_session(s);
4424                 if (ret < 0)
4425                         pr_err("unable to close session to mds%d: %d\n",
4426                                s->s_mds, ret);
4427         }
4428 }
4429
4430 /*
4431  * delayed work -- periodically trim expired leases, renew caps with mds
4432  */
4433 static void schedule_delayed(struct ceph_mds_client *mdsc)
4434 {
4435         int delay = 5;
4436         unsigned hz = round_jiffies_relative(HZ * delay);
4437         schedule_delayed_work(&mdsc->delayed_work, hz);
4438 }
4439
4440 static void delayed_work(struct work_struct *work)
4441 {
4442         int i;
4443         struct ceph_mds_client *mdsc =
4444                 container_of(work, struct ceph_mds_client, delayed_work.work);
4445         int renew_interval;
4446         int renew_caps;
4447
4448         dout("mdsc delayed_work\n");
4449
4450         if (mdsc->stopping)
4451                 return;
4452
4453         mutex_lock(&mdsc->mutex);
4454         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
4455         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
4456                                    mdsc->last_renew_caps);
4457         if (renew_caps)
4458                 mdsc->last_renew_caps = jiffies;
4459
4460         for (i = 0; i < mdsc->max_sessions; i++) {
4461                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4462                 if (!s)
4463                         continue;
4464
4465                 if (!check_session_state(s)) {
4466                         ceph_put_mds_session(s);
4467                         continue;
4468                 }
4469                 mutex_unlock(&mdsc->mutex);
4470
4471                 mutex_lock(&s->s_mutex);
4472                 if (renew_caps)
4473                         send_renew_caps(mdsc, s);
4474                 else
4475                         ceph_con_keepalive(&s->s_con);
4476                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4477                     s->s_state == CEPH_MDS_SESSION_HUNG)
4478                         ceph_send_cap_releases(mdsc, s);
4479                 mutex_unlock(&s->s_mutex);
4480                 ceph_put_mds_session(s);
4481
4482                 mutex_lock(&mdsc->mutex);
4483         }
4484         mutex_unlock(&mdsc->mutex);
4485
4486         ceph_check_delayed_caps(mdsc);
4487
4488         ceph_queue_cap_reclaim_work(mdsc);
4489
4490         ceph_trim_snapid_map(mdsc);
4491
4492         maybe_recover_session(mdsc);
4493
4494         schedule_delayed(mdsc);
4495 }
4496
4497 int ceph_mdsc_init(struct ceph_fs_client *fsc)
4498
4499 {
4500         struct ceph_mds_client *mdsc;
4501         int err;
4502
4503         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
4504         if (!mdsc)
4505                 return -ENOMEM;
4506         mdsc->fsc = fsc;
4507         mutex_init(&mdsc->mutex);
4508         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
4509         if (!mdsc->mdsmap) {
4510                 err = -ENOMEM;
4511                 goto err_mdsc;
4512         }
4513
4514         init_completion(&mdsc->safe_umount_waiters);
4515         init_waitqueue_head(&mdsc->session_close_wq);
4516         INIT_LIST_HEAD(&mdsc->waiting_for_map);
4517         mdsc->sessions = NULL;
4518         atomic_set(&mdsc->num_sessions, 0);
4519         mdsc->max_sessions = 0;
4520         mdsc->stopping = 0;
4521         atomic64_set(&mdsc->quotarealms_count, 0);
4522         mdsc->quotarealms_inodes = RB_ROOT;
4523         mutex_init(&mdsc->quotarealms_inodes_mutex);
4524         mdsc->last_snap_seq = 0;
4525         init_rwsem(&mdsc->snap_rwsem);
4526         mdsc->snap_realms = RB_ROOT;
4527         INIT_LIST_HEAD(&mdsc->snap_empty);
4528         mdsc->num_snap_realms = 0;
4529         spin_lock_init(&mdsc->snap_empty_lock);
4530         mdsc->last_tid = 0;
4531         mdsc->oldest_tid = 0;
4532         mdsc->request_tree = RB_ROOT;
4533         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
4534         mdsc->last_renew_caps = jiffies;
4535         INIT_LIST_HEAD(&mdsc->cap_delay_list);
4536         INIT_LIST_HEAD(&mdsc->cap_wait_list);
4537         spin_lock_init(&mdsc->cap_delay_lock);
4538         INIT_LIST_HEAD(&mdsc->snap_flush_list);
4539         spin_lock_init(&mdsc->snap_flush_lock);
4540         mdsc->last_cap_flush_tid = 1;
4541         INIT_LIST_HEAD(&mdsc->cap_flush_list);
4542         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
4543         mdsc->num_cap_flushing = 0;
4544         spin_lock_init(&mdsc->cap_dirty_lock);
4545         init_waitqueue_head(&mdsc->cap_flushing_wq);
4546         INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
4547         atomic_set(&mdsc->cap_reclaim_pending, 0);
4548         err = ceph_metric_init(&mdsc->metric);
4549         if (err)
4550                 goto err_mdsmap;
4551
4552         spin_lock_init(&mdsc->dentry_list_lock);
4553         INIT_LIST_HEAD(&mdsc->dentry_leases);
4554         INIT_LIST_HEAD(&mdsc->dentry_dir_leases);
4555
4556         ceph_caps_init(mdsc);
4557         ceph_adjust_caps_max_min(mdsc, fsc->mount_options);
4558
4559         spin_lock_init(&mdsc->snapid_map_lock);
4560         mdsc->snapid_map_tree = RB_ROOT;
4561         INIT_LIST_HEAD(&mdsc->snapid_map_lru);
4562
4563         init_rwsem(&mdsc->pool_perm_rwsem);
4564         mdsc->pool_perm_tree = RB_ROOT;
4565
4566         strscpy(mdsc->nodename, utsname()->nodename,
4567                 sizeof(mdsc->nodename));
4568
4569         fsc->mdsc = mdsc;
4570         return 0;
4571
4572 err_mdsmap:
4573         kfree(mdsc->mdsmap);
4574 err_mdsc:
4575         kfree(mdsc);
4576         return err;
4577 }
4578
4579 /*
4580  * Wait for safe replies on open mds requests.  If we time out, drop
4581  * all requests from the tree to avoid dangling dentry refs.
4582  */
4583 static void wait_requests(struct ceph_mds_client *mdsc)
4584 {
4585         struct ceph_options *opts = mdsc->fsc->client->options;
4586         struct ceph_mds_request *req;
4587
4588         mutex_lock(&mdsc->mutex);
4589         if (__get_oldest_req(mdsc)) {
4590                 mutex_unlock(&mdsc->mutex);
4591
4592                 dout("wait_requests waiting for requests\n");
4593                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
4594                                     ceph_timeout_jiffies(opts->mount_timeout));
4595
4596                 /* tear down remaining requests */
4597                 mutex_lock(&mdsc->mutex);
4598                 while ((req = __get_oldest_req(mdsc))) {
4599                         dout("wait_requests timed out on tid %llu\n",
4600                              req->r_tid);
4601                         list_del_init(&req->r_wait);
4602                         __unregister_request(mdsc, req);
4603                 }
4604         }
4605         mutex_unlock(&mdsc->mutex);
4606         dout("wait_requests done\n");
4607 }
4608
4609 /*
4610  * called before mount is ro, and before dentries are torn down.
4611  * (hmm, does this still race with new lookups?)
4612  */
4613 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
4614 {
4615         dout("pre_umount\n");
4616         mdsc->stopping = 1;
4617
4618         lock_unlock_sessions(mdsc);
4619         ceph_flush_dirty_caps(mdsc);
4620         wait_requests(mdsc);
4621
4622         /*
4623          * wait for reply handlers to drop their request refs and
4624          * their inode/dcache refs
4625          */
4626         ceph_msgr_flush();
4627
4628         ceph_cleanup_quotarealms_inodes(mdsc);
4629 }
4630
4631 /*
4632  * wait for all write mds requests to flush.
4633  */
4634 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
4635 {
4636         struct ceph_mds_request *req = NULL, *nextreq;
4637         struct rb_node *n;
4638
4639         mutex_lock(&mdsc->mutex);
4640         dout("wait_unsafe_requests want %lld\n", want_tid);
4641 restart:
4642         req = __get_oldest_req(mdsc);
4643         while (req && req->r_tid <= want_tid) {
4644                 /* find next request */
4645                 n = rb_next(&req->r_node);
4646                 if (n)
4647                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
4648                 else
4649                         nextreq = NULL;
4650                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
4651                     (req->r_op & CEPH_MDS_OP_WRITE)) {
4652                         /* write op */
4653                         ceph_mdsc_get_request(req);
4654                         if (nextreq)
4655                                 ceph_mdsc_get_request(nextreq);
4656                         mutex_unlock(&mdsc->mutex);
4657                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
4658                              req->r_tid, want_tid);
4659                         wait_for_completion(&req->r_safe_completion);
4660                         mutex_lock(&mdsc->mutex);
4661                         ceph_mdsc_put_request(req);
4662                         if (!nextreq)
4663                                 break;  /* next dne before, so we're done! */
4664                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
4665                                 /* next request was removed from tree */
4666                                 ceph_mdsc_put_request(nextreq);
4667                                 goto restart;
4668                         }
4669                         ceph_mdsc_put_request(nextreq);  /* won't go away */
4670                 }
4671                 req = nextreq;
4672         }
4673         mutex_unlock(&mdsc->mutex);
4674         dout("wait_unsafe_requests done\n");
4675 }
4676
4677 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
4678 {
4679         u64 want_tid, want_flush;
4680
4681         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4682                 return;
4683
4684         dout("sync\n");
4685         mutex_lock(&mdsc->mutex);
4686         want_tid = mdsc->last_tid;
4687         mutex_unlock(&mdsc->mutex);
4688
4689         ceph_flush_dirty_caps(mdsc);
4690         spin_lock(&mdsc->cap_dirty_lock);
4691         want_flush = mdsc->last_cap_flush_tid;
4692         if (!list_empty(&mdsc->cap_flush_list)) {
4693                 struct ceph_cap_flush *cf =
4694                         list_last_entry(&mdsc->cap_flush_list,
4695                                         struct ceph_cap_flush, g_list);
4696                 cf->wake = true;
4697         }
4698         spin_unlock(&mdsc->cap_dirty_lock);
4699
4700         dout("sync want tid %lld flush_seq %lld\n",
4701              want_tid, want_flush);
4702
4703         wait_unsafe_requests(mdsc, want_tid);
4704         wait_caps_flush(mdsc, want_flush);
4705 }
4706
4707 /*
4708  * true if all sessions are closed, or we force unmount
4709  */
4710 static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
4711 {
4712         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4713                 return true;
4714         return atomic_read(&mdsc->num_sessions) <= skipped;
4715 }
4716
4717 /*
4718  * called after sb is ro.
4719  */
4720 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
4721 {
4722         struct ceph_options *opts = mdsc->fsc->client->options;
4723         struct ceph_mds_session *session;
4724         int i;
4725         int skipped = 0;
4726
4727         dout("close_sessions\n");
4728
4729         /* close sessions */
4730         mutex_lock(&mdsc->mutex);
4731         for (i = 0; i < mdsc->max_sessions; i++) {
4732                 session = __ceph_lookup_mds_session(mdsc, i);
4733                 if (!session)
4734                         continue;
4735                 mutex_unlock(&mdsc->mutex);
4736                 mutex_lock(&session->s_mutex);
4737                 if (__close_session(mdsc, session) <= 0)
4738                         skipped++;
4739                 mutex_unlock(&session->s_mutex);
4740                 ceph_put_mds_session(session);
4741                 mutex_lock(&mdsc->mutex);
4742         }
4743         mutex_unlock(&mdsc->mutex);
4744
4745         dout("waiting for sessions to close\n");
4746         wait_event_timeout(mdsc->session_close_wq,
4747                            done_closing_sessions(mdsc, skipped),
4748                            ceph_timeout_jiffies(opts->mount_timeout));
4749
4750         /* tear down remaining sessions */
4751         mutex_lock(&mdsc->mutex);
4752         for (i = 0; i < mdsc->max_sessions; i++) {
4753                 if (mdsc->sessions[i]) {
4754                         session = ceph_get_mds_session(mdsc->sessions[i]);
4755                         __unregister_session(mdsc, session);
4756                         mutex_unlock(&mdsc->mutex);
4757                         mutex_lock(&session->s_mutex);
4758                         remove_session_caps(session);
4759                         mutex_unlock(&session->s_mutex);
4760                         ceph_put_mds_session(session);
4761                         mutex_lock(&mdsc->mutex);
4762                 }
4763         }
4764         WARN_ON(!list_empty(&mdsc->cap_delay_list));
4765         mutex_unlock(&mdsc->mutex);
4766
4767         ceph_cleanup_snapid_map(mdsc);
4768         ceph_cleanup_empty_realms(mdsc);
4769
4770         cancel_work_sync(&mdsc->cap_reclaim_work);
4771         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4772
4773         dout("stopped\n");
4774 }
4775
4776 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
4777 {
4778         struct ceph_mds_session *session;
4779         int mds;
4780
4781         dout("force umount\n");
4782
4783         mutex_lock(&mdsc->mutex);
4784         for (mds = 0; mds < mdsc->max_sessions; mds++) {
4785                 session = __ceph_lookup_mds_session(mdsc, mds);
4786                 if (!session)
4787                         continue;
4788
4789                 if (session->s_state == CEPH_MDS_SESSION_REJECTED)
4790                         __unregister_session(mdsc, session);
4791                 __wake_requests(mdsc, &session->s_waiting);
4792                 mutex_unlock(&mdsc->mutex);
4793
4794                 mutex_lock(&session->s_mutex);
4795                 __close_session(mdsc, session);
4796                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
4797                         cleanup_session_requests(mdsc, session);
4798                         remove_session_caps(session);
4799                 }
4800                 mutex_unlock(&session->s_mutex);
4801                 ceph_put_mds_session(session);
4802
4803                 mutex_lock(&mdsc->mutex);
4804                 kick_requests(mdsc, mds);
4805         }
4806         __wake_requests(mdsc, &mdsc->waiting_for_map);
4807         mutex_unlock(&mdsc->mutex);
4808 }
4809
4810 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
4811 {
4812         dout("stop\n");
4813         /*
4814          * Make sure the delayed work stopped before releasing
4815          * the resources.
4816          *
4817          * Because the cancel_delayed_work_sync() will only
4818          * guarantee that the work finishes executing. But the
4819          * delayed work will re-arm itself again after that.
4820          */
4821         flush_delayed_work(&mdsc->delayed_work);
4822
4823         if (mdsc->mdsmap)
4824                 ceph_mdsmap_destroy(mdsc->mdsmap);
4825         kfree(mdsc->sessions);
4826         ceph_caps_finalize(mdsc);
4827         ceph_pool_perm_destroy(mdsc);
4828 }
4829
4830 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
4831 {
4832         struct ceph_mds_client *mdsc = fsc->mdsc;
4833         dout("mdsc_destroy %p\n", mdsc);
4834
4835         if (!mdsc)
4836                 return;
4837
4838         /* flush out any connection work with references to us */
4839         ceph_msgr_flush();
4840
4841         ceph_mdsc_stop(mdsc);
4842
4843         ceph_metric_destroy(&mdsc->metric);
4844
4845         flush_delayed_work(&mdsc->metric.delayed_work);
4846         fsc->mdsc = NULL;
4847         kfree(mdsc);
4848         dout("mdsc_destroy %p done\n", mdsc);
4849 }
4850
4851 void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4852 {
4853         struct ceph_fs_client *fsc = mdsc->fsc;
4854         const char *mds_namespace = fsc->mount_options->mds_namespace;
4855         void *p = msg->front.iov_base;
4856         void *end = p + msg->front.iov_len;
4857         u32 epoch;
4858         u32 map_len;
4859         u32 num_fs;
4860         u32 mount_fscid = (u32)-1;
4861         u8 struct_v, struct_cv;
4862         int err = -EINVAL;
4863
4864         ceph_decode_need(&p, end, sizeof(u32), bad);
4865         epoch = ceph_decode_32(&p);
4866
4867         dout("handle_fsmap epoch %u\n", epoch);
4868
4869         ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4870         struct_v = ceph_decode_8(&p);
4871         struct_cv = ceph_decode_8(&p);
4872         map_len = ceph_decode_32(&p);
4873
4874         ceph_decode_need(&p, end, sizeof(u32) * 3, bad);
4875         p += sizeof(u32) * 2; /* skip epoch and legacy_client_fscid */
4876
4877         num_fs = ceph_decode_32(&p);
4878         while (num_fs-- > 0) {
4879                 void *info_p, *info_end;
4880                 u32 info_len;
4881                 u8 info_v, info_cv;
4882                 u32 fscid, namelen;
4883
4884                 ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4885                 info_v = ceph_decode_8(&p);
4886                 info_cv = ceph_decode_8(&p);
4887                 info_len = ceph_decode_32(&p);
4888                 ceph_decode_need(&p, end, info_len, bad);
4889                 info_p = p;
4890                 info_end = p + info_len;
4891                 p = info_end;
4892
4893                 ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
4894                 fscid = ceph_decode_32(&info_p);
4895                 namelen = ceph_decode_32(&info_p);
4896                 ceph_decode_need(&info_p, info_end, namelen, bad);
4897
4898                 if (mds_namespace &&
4899                     strlen(mds_namespace) == namelen &&
4900                     !strncmp(mds_namespace, (char *)info_p, namelen)) {
4901                         mount_fscid = fscid;
4902                         break;
4903                 }
4904         }
4905
4906         ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
4907         if (mount_fscid != (u32)-1) {
4908                 fsc->client->monc.fs_cluster_id = mount_fscid;
4909                 ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
4910                                    0, true);
4911                 ceph_monc_renew_subs(&fsc->client->monc);
4912         } else {
4913                 err = -ENOENT;
4914                 goto err_out;
4915         }
4916         return;
4917
4918 bad:
4919         pr_err("error decoding fsmap\n");
4920 err_out:
4921         mutex_lock(&mdsc->mutex);
4922         mdsc->mdsmap_err = err;
4923         __wake_requests(mdsc, &mdsc->waiting_for_map);
4924         mutex_unlock(&mdsc->mutex);
4925 }
4926
4927 /*
4928  * handle mds map update.
4929  */
4930 void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4931 {
4932         u32 epoch;
4933         u32 maplen;
4934         void *p = msg->front.iov_base;
4935         void *end = p + msg->front.iov_len;
4936         struct ceph_mdsmap *newmap, *oldmap;
4937         struct ceph_fsid fsid;
4938         int err = -EINVAL;
4939
4940         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
4941         ceph_decode_copy(&p, &fsid, sizeof(fsid));
4942         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
4943                 return;
4944         epoch = ceph_decode_32(&p);
4945         maplen = ceph_decode_32(&p);
4946         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
4947
4948         /* do we need it? */
4949         mutex_lock(&mdsc->mutex);
4950         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
4951                 dout("handle_map epoch %u <= our %u\n",
4952                      epoch, mdsc->mdsmap->m_epoch);
4953                 mutex_unlock(&mdsc->mutex);
4954                 return;
4955         }
4956
4957         newmap = ceph_mdsmap_decode(&p, end);
4958         if (IS_ERR(newmap)) {
4959                 err = PTR_ERR(newmap);
4960                 goto bad_unlock;
4961         }
4962
4963         /* swap into place */
4964         if (mdsc->mdsmap) {
4965                 oldmap = mdsc->mdsmap;
4966                 mdsc->mdsmap = newmap;
4967                 check_new_map(mdsc, newmap, oldmap);
4968                 ceph_mdsmap_destroy(oldmap);
4969         } else {
4970                 mdsc->mdsmap = newmap;  /* first mds map */
4971         }
4972         mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
4973                                         MAX_LFS_FILESIZE);
4974
4975         __wake_requests(mdsc, &mdsc->waiting_for_map);
4976         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
4977                           mdsc->mdsmap->m_epoch);
4978
4979         mutex_unlock(&mdsc->mutex);
4980         schedule_delayed(mdsc);
4981         return;
4982
4983 bad_unlock:
4984         mutex_unlock(&mdsc->mutex);
4985 bad:
4986         pr_err("error decoding mdsmap %d\n", err);
4987         return;
4988 }
4989
4990 static struct ceph_connection *con_get(struct ceph_connection *con)
4991 {
4992         struct ceph_mds_session *s = con->private;
4993
4994         if (ceph_get_mds_session(s))
4995                 return con;
4996         return NULL;
4997 }
4998
4999 static void con_put(struct ceph_connection *con)
5000 {
5001         struct ceph_mds_session *s = con->private;
5002
5003         ceph_put_mds_session(s);
5004 }
5005
5006 /*
5007  * if the client is unresponsive for long enough, the mds will kill
5008  * the session entirely.
5009  */
5010 static void peer_reset(struct ceph_connection *con)
5011 {
5012         struct ceph_mds_session *s = con->private;
5013         struct ceph_mds_client *mdsc = s->s_mdsc;
5014
5015         pr_warn("mds%d closed our session\n", s->s_mds);
5016         send_mds_reconnect(mdsc, s);
5017 }
5018
5019 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
5020 {
5021         struct ceph_mds_session *s = con->private;
5022         struct ceph_mds_client *mdsc = s->s_mdsc;
5023         int type = le16_to_cpu(msg->hdr.type);
5024
5025         mutex_lock(&mdsc->mutex);
5026         if (__verify_registered_session(mdsc, s) < 0) {
5027                 mutex_unlock(&mdsc->mutex);
5028                 goto out;
5029         }
5030         mutex_unlock(&mdsc->mutex);
5031
5032         switch (type) {
5033         case CEPH_MSG_MDS_MAP:
5034                 ceph_mdsc_handle_mdsmap(mdsc, msg);
5035                 break;
5036         case CEPH_MSG_FS_MAP_USER:
5037                 ceph_mdsc_handle_fsmap(mdsc, msg);
5038                 break;
5039         case CEPH_MSG_CLIENT_SESSION:
5040                 handle_session(s, msg);
5041                 break;
5042         case CEPH_MSG_CLIENT_REPLY:
5043                 handle_reply(s, msg);
5044                 break;
5045         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
5046                 handle_forward(mdsc, s, msg);
5047                 break;
5048         case CEPH_MSG_CLIENT_CAPS:
5049                 ceph_handle_caps(s, msg);
5050                 break;
5051         case CEPH_MSG_CLIENT_SNAP:
5052                 ceph_handle_snap(mdsc, s, msg);
5053                 break;
5054         case CEPH_MSG_CLIENT_LEASE:
5055                 handle_lease(mdsc, s, msg);
5056                 break;
5057         case CEPH_MSG_CLIENT_QUOTA:
5058                 ceph_handle_quota(mdsc, s, msg);
5059                 break;
5060
5061         default:
5062                 pr_err("received unknown message type %d %s\n", type,
5063                        ceph_msg_type_name(type));
5064         }
5065 out:
5066         ceph_msg_put(msg);
5067 }
5068
5069 /*
5070  * authentication
5071  */
5072
5073 /*
5074  * Note: returned pointer is the address of a structure that's
5075  * managed separately.  Caller must *not* attempt to free it.
5076  */
5077 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
5078                                         int *proto, int force_new)
5079 {
5080         struct ceph_mds_session *s = con->private;
5081         struct ceph_mds_client *mdsc = s->s_mdsc;
5082         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5083         struct ceph_auth_handshake *auth = &s->s_auth;
5084
5085         if (force_new && auth->authorizer) {
5086                 ceph_auth_destroy_authorizer(auth->authorizer);
5087                 auth->authorizer = NULL;
5088         }
5089         if (!auth->authorizer) {
5090                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
5091                                                       auth);
5092                 if (ret)
5093                         return ERR_PTR(ret);
5094         } else {
5095                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
5096                                                       auth);
5097                 if (ret)
5098                         return ERR_PTR(ret);
5099         }
5100         *proto = ac->protocol;
5101
5102         return auth;
5103 }
5104
5105 static int add_authorizer_challenge(struct ceph_connection *con,
5106                                     void *challenge_buf, int challenge_buf_len)
5107 {
5108         struct ceph_mds_session *s = con->private;
5109         struct ceph_mds_client *mdsc = s->s_mdsc;
5110         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5111
5112         return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
5113                                             challenge_buf, challenge_buf_len);
5114 }
5115
5116 static int verify_authorizer_reply(struct ceph_connection *con)
5117 {
5118         struct ceph_mds_session *s = con->private;
5119         struct ceph_mds_client *mdsc = s->s_mdsc;
5120         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5121
5122         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer);
5123 }
5124
5125 static int invalidate_authorizer(struct ceph_connection *con)
5126 {
5127         struct ceph_mds_session *s = con->private;
5128         struct ceph_mds_client *mdsc = s->s_mdsc;
5129         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5130
5131         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
5132
5133         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
5134 }
5135
5136 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
5137                                 struct ceph_msg_header *hdr, int *skip)
5138 {
5139         struct ceph_msg *msg;
5140         int type = (int) le16_to_cpu(hdr->type);
5141         int front_len = (int) le32_to_cpu(hdr->front_len);
5142
5143         if (con->in_msg)
5144                 return con->in_msg;
5145
5146         *skip = 0;
5147         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
5148         if (!msg) {
5149                 pr_err("unable to allocate msg type %d len %d\n",
5150                        type, front_len);
5151                 return NULL;
5152         }
5153
5154         return msg;
5155 }
5156
5157 static int mds_sign_message(struct ceph_msg *msg)
5158 {
5159        struct ceph_mds_session *s = msg->con->private;
5160        struct ceph_auth_handshake *auth = &s->s_auth;
5161
5162        return ceph_auth_sign_message(auth, msg);
5163 }
5164
5165 static int mds_check_message_signature(struct ceph_msg *msg)
5166 {
5167        struct ceph_mds_session *s = msg->con->private;
5168        struct ceph_auth_handshake *auth = &s->s_auth;
5169
5170        return ceph_auth_check_message_signature(auth, msg);
5171 }
5172
5173 static const struct ceph_connection_operations mds_con_ops = {
5174         .get = con_get,
5175         .put = con_put,
5176         .dispatch = dispatch,
5177         .get_authorizer = get_authorizer,
5178         .add_authorizer_challenge = add_authorizer_challenge,
5179         .verify_authorizer_reply = verify_authorizer_reply,
5180         .invalidate_authorizer = invalidate_authorizer,
5181         .peer_reset = peer_reset,
5182         .alloc_msg = mds_alloc_msg,
5183         .sign_message = mds_sign_message,
5184         .check_message_signature = mds_check_message_signature,
5185 };
5186
5187 /* eof */