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
  13 #include "super.h"
  14 #include "mds_client.h"
  15
  16 #include <linux/ceph/ceph_features.h>
  17 #include <linux/ceph/messenger.h>
  18 #include <linux/ceph/decode.h>
  19 #include <linux/ceph/pagelist.h>
  20 #include <linux/ceph/auth.h>
  21 #include <linux/ceph/debugfs.h>
  22
  23 #define RECONNECT_MAX_SIZE (INT_MAX - PAGE_SIZE)
  24
  25 /*
  26  * A cluster of MDS (metadata server) daemons is responsible for
  27  * managing the file system namespace (the directory hierarchy and
  28  * inodes) and for coordinating shared access to storage.  Metadata is
  29  * partitioning hierarchically across a number of servers, and that
  30  * partition varies over time as the cluster adjusts the distribution
  31  * in order to balance load.
  32  *
  33  * The MDS client is primarily responsible to managing synchronous
  34  * metadata requests for operations like open, unlink, and so forth.
  35  * If there is a MDS failure, we find out about it when we (possibly
  36  * request and) receive a new MDS map, and can resubmit affected
  37  * requests.
  38  *
  39  * For the most part, though, we take advantage of a lossless
  40  * communications channel to the MDS, and do not need to worry about
  41  * timing out or resubmitting requests.
  42  *
  43  * We maintain a stateful "session" with each MDS we interact with.
  44  * Within each session, we sent periodic heartbeat messages to ensure
  45  * any capabilities or leases we have been issues remain valid.  If
  46  * the session times out and goes stale, our leases and capabilities
  47  * are no longer valid.
  48  */
  49
  50 struct ceph_reconnect_state {
  51         struct ceph_mds_session *session;
  52         int nr_caps, nr_realms;
  53         struct ceph_pagelist *pagelist;
  54         unsigned msg_version;
  55         bool allow_multi;
  56 };
  57
  58 static void __wake_requests(struct ceph_mds_client *mdsc,
  59                             struct list_head *head);
  60 static void ceph_cap_release_work(struct work_struct *work);
  61 static void ceph_cap_reclaim_work(struct work_struct *work);
  62
  63 static const struct ceph_connection_operations mds_con_ops;
  64
  65
  66 /*
  67  * mds reply parsing
  68  */
  69
  70 static int parse_reply_info_quota(void **p, void *end,
  71                                   struct ceph_mds_reply_info_in *info)
  72 {
  73         u8 struct_v, struct_compat;
  74         u32 struct_len;
  75
  76         ceph_decode_8_safe(p, end, struct_v, bad);
  77         ceph_decode_8_safe(p, end, struct_compat, bad);
  78         /* struct_v is expected to be >= 1. we only
  79          * understand encoding with struct_compat == 1. */
  80         if (!struct_v || struct_compat != 1)
  81                 goto bad;
  82         ceph_decode_32_safe(p, end, struct_len, bad);
  83         ceph_decode_need(p, end, struct_len, bad);
  84         end = *p + struct_len;
  85         ceph_decode_64_safe(p, end, info->max_bytes, bad);
  86         ceph_decode_64_safe(p, end, info->max_files, bad);
  87         *p = end;
  88         return 0;
  89 bad:
  90         return -EIO;
  91 }
  92
  93 /*
  94  * parse individual inode info
  95  */
  96 static int parse_reply_info_in(void **p, void *end,
  97                                struct ceph_mds_reply_info_in *info,
  98                                u64 features)
  99 {
 100         int err = 0;
 101         u8 struct_v = 0;
 102
 103         if (features == (u64)-1) {
 104                 u32 struct_len;
 105                 u8 struct_compat;
 106                 ceph_decode_8_safe(p, end, struct_v, bad);
 107                 ceph_decode_8_safe(p, end, struct_compat, bad);
 108                 /* struct_v is expected to be >= 1. we only understand
 109                  * encoding with struct_compat == 1. */
 110                 if (!struct_v || struct_compat != 1)
 111                         goto bad;
 112                 ceph_decode_32_safe(p, end, struct_len, bad);
 113                 ceph_decode_need(p, end, struct_len, bad);
 114                 end = *p + struct_len;
 115         }
 116
 117         ceph_decode_need(p, end, sizeof(struct ceph_mds_reply_inode), bad);
 118         info->in = *p;
 119         *p += sizeof(struct ceph_mds_reply_inode) +
 120                 sizeof(*info->in->fragtree.splits) *
 121                 le32_to_cpu(info->in->fragtree.nsplits);
 122
 123         ceph_decode_32_safe(p, end, info->symlink_len, bad);
 124         ceph_decode_need(p, end, info->symlink_len, bad);
 125         info->symlink = *p;
 126         *p += info->symlink_len;
 127
 128         ceph_decode_copy_safe(p, end, &info->dir_layout,
 129                               sizeof(info->dir_layout), bad);
 130         ceph_decode_32_safe(p, end, info->xattr_len, bad);
 131         ceph_decode_need(p, end, info->xattr_len, bad);
 132         info->xattr_data = *p;
 133         *p += info->xattr_len;
 134
 135         if (features == (u64)-1) {
 136                 /* inline data */
 137                 ceph_decode_64_safe(p, end, info->inline_version, bad);
 138                 ceph_decode_32_safe(p, end, info->inline_len, bad);
 139                 ceph_decode_need(p, end, info->inline_len, bad);
 140                 info->inline_data = *p;
 141                 *p += info->inline_len;
 142                 /* quota */
 143                 err = parse_reply_info_quota(p, end, info);
 144                 if (err < 0)
 145                         goto out_bad;
 146                 /* pool namespace */
 147                 ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 148                 if (info->pool_ns_len > 0) {
 149                         ceph_decode_need(p, end, info->pool_ns_len, bad);
 150                         info->pool_ns_data = *p;
 151                         *p += info->pool_ns_len;
 152                 }
 153
 154                 /* btime */
 155                 ceph_decode_need(p, end, sizeof(info->btime), bad);
 156                 ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 157
 158                 /* change attribute */
 159                 ceph_decode_64_safe(p, end, info->change_attr, bad);
 160
 161                 /* dir pin */
 162                 if (struct_v >= 2) {
 163                         ceph_decode_32_safe(p, end, info->dir_pin, bad);
 164                 } else {
 165                         info->dir_pin = -ENODATA;
 166                 }
 167
 168                 /* snapshot birth time, remains zero for v<=2 */
 169                 if (struct_v >= 3) {
 170                         ceph_decode_need(p, end, sizeof(info->snap_btime), bad);
 171                         ceph_decode_copy(p, &info->snap_btime,
 172                                          sizeof(info->snap_btime));
 173                 } else {
 174                         memset(&info->snap_btime, 0, sizeof(info->snap_btime));
 175                 }
 176
 177                 *p = end;
 178         } else {
 179                 if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
 180                         ceph_decode_64_safe(p, end, info->inline_version, bad);
 181                         ceph_decode_32_safe(p, end, info->inline_len, bad);
 182                         ceph_decode_need(p, end, info->inline_len, bad);
 183                         info->inline_data = *p;
 184                         *p += info->inline_len;
 185                 } else
 186                         info->inline_version = CEPH_INLINE_NONE;
 187
 188                 if (features & CEPH_FEATURE_MDS_QUOTA) {
 189                         err = parse_reply_info_quota(p, end, info);
 190                         if (err < 0)
 191                                 goto out_bad;
 192                 } else {
 193                         info->max_bytes = 0;
 194                         info->max_files = 0;
 195                 }
 196
 197                 info->pool_ns_len = 0;
 198                 info->pool_ns_data = NULL;
 199                 if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 200                         ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 201                         if (info->pool_ns_len > 0) {
 202                                 ceph_decode_need(p, end, info->pool_ns_len, bad);
 203                                 info->pool_ns_data = *p;
 204                                 *p += info->pool_ns_len;
 205                         }
 206                 }
 207
 208                 if (features & CEPH_FEATURE_FS_BTIME) {
 209                         ceph_decode_need(p, end, sizeof(info->btime), bad);
 210                         ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 211                         ceph_decode_64_safe(p, end, info->change_attr, bad);
 212                 }
 213
 214                 info->dir_pin = -ENODATA;
 215                 /* info->snap_btime remains zero */
 216         }
 217         return 0;
 218 bad:
 219         err = -EIO;
 220 out_bad:
 221         return err;
 222 }
 223
 224 static int parse_reply_info_dir(void **p, void *end,
 225                                 struct ceph_mds_reply_dirfrag **dirfrag,
 226                                 u64 features)
 227 {
 228         if (features == (u64)-1) {
 229                 u8 struct_v, struct_compat;
 230                 u32 struct_len;
 231                 ceph_decode_8_safe(p, end, struct_v, bad);
 232                 ceph_decode_8_safe(p, end, struct_compat, bad);
 233                 /* struct_v is expected to be >= 1. we only understand
 234                  * encoding whose struct_compat == 1. */
 235                 if (!struct_v || struct_compat != 1)
 236                         goto bad;
 237                 ceph_decode_32_safe(p, end, struct_len, bad);
 238                 ceph_decode_need(p, end, struct_len, bad);
 239                 end = *p + struct_len;
 240         }
 241
 242         ceph_decode_need(p, end, sizeof(**dirfrag), bad);
 243         *dirfrag = *p;
 244         *p += sizeof(**dirfrag) + sizeof(u32) * le32_to_cpu((*dirfrag)->ndist);
 245         if (unlikely(*p > end))
 246                 goto bad;
 247         if (features == (u64)-1)
 248                 *p = end;
 249         return 0;
 250 bad:
 251         return -EIO;
 252 }
 253
 254 static int parse_reply_info_lease(void **p, void *end,
 255                                   struct ceph_mds_reply_lease **lease,
 256                                   u64 features)
 257 {
 258         if (features == (u64)-1) {
 259                 u8 struct_v, struct_compat;
 260                 u32 struct_len;
 261                 ceph_decode_8_safe(p, end, struct_v, bad);
 262                 ceph_decode_8_safe(p, end, struct_compat, bad);
 263                 /* struct_v is expected to be >= 1. we only understand
 264                  * encoding whose struct_compat == 1. */
 265                 if (!struct_v || struct_compat != 1)
 266                         goto bad;
 267                 ceph_decode_32_safe(p, end, struct_len, bad);
 268                 ceph_decode_need(p, end, struct_len, bad);
 269                 end = *p + struct_len;
 270         }
 271
 272         ceph_decode_need(p, end, sizeof(**lease), bad);
 273         *lease = *p;
 274         *p += sizeof(**lease);
 275         if (features == (u64)-1)
 276                 *p = end;
 277         return 0;
 278 bad:
 279         return -EIO;
 280 }
 281
 282 /*
 283  * parse a normal reply, which may contain a (dir+)dentry and/or a
 284  * target inode.
 285  */
 286 static int parse_reply_info_trace(void **p, void *end,
 287                                   struct ceph_mds_reply_info_parsed *info,
 288                                   u64 features)
 289 {
 290         int err;
 291
 292         if (info->head->is_dentry) {
 293                 err = parse_reply_info_in(p, end, &info->diri, features);
 294                 if (err < 0)
 295                         goto out_bad;
 296
 297                 err = parse_reply_info_dir(p, end, &info->dirfrag, features);
 298                 if (err < 0)
 299                         goto out_bad;
 300
 301                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 302                 ceph_decode_need(p, end, info->dname_len, bad);
 303                 info->dname = *p;
 304                 *p += info->dname_len;
 305
 306                 err = parse_reply_info_lease(p, end, &info->dlease, features);
 307                 if (err < 0)
 308                         goto out_bad;
 309         }
 310
 311         if (info->head->is_target) {
 312                 err = parse_reply_info_in(p, end, &info->targeti, features);
 313                 if (err < 0)
 314                         goto out_bad;
 315         }
 316
 317         if (unlikely(*p != end))
 318                 goto bad;
 319         return 0;
 320
 321 bad:
 322         err = -EIO;
 323 out_bad:
 324         pr_err("problem parsing mds trace %d\n", err);
 325         return err;
 326 }
 327
 328 /*
 329  * parse readdir results
 330  */
 331 static int parse_reply_info_readdir(void **p, void *end,
 332                                 struct ceph_mds_reply_info_parsed *info,
 333                                 u64 features)
 334 {
 335         u32 num, i = 0;
 336         int err;
 337
 338         err = parse_reply_info_dir(p, end, &info->dir_dir, features);
 339         if (err < 0)
 340                 goto out_bad;
 341
 342         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 343         num = ceph_decode_32(p);
 344         {
 345                 u16 flags = ceph_decode_16(p);
 346                 info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 347                 info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 348                 info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 349                 info->offset_hash = !!(flags & CEPH_READDIR_OFFSET_HASH);
 350         }
 351         if (num == 0)
 352                 goto done;
 353
 354         BUG_ON(!info->dir_entries);
 355         if ((unsigned long)(info->dir_entries + num) >
 356             (unsigned long)info->dir_entries + info->dir_buf_size) {
 357                 pr_err("dir contents are larger than expected\n");
 358                 WARN_ON(1);
 359                 goto bad;
 360         }
 361
 362         info->dir_nr = num;
 363         while (num) {
 364                 struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 365                 /* dentry */
 366                 ceph_decode_32_safe(p, end, rde->name_len, bad);
 367                 ceph_decode_need(p, end, rde->name_len, bad);
 368                 rde->name = *p;
 369                 *p += rde->name_len;
 370                 dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 371
 372                 /* dentry lease */
 373                 err = parse_reply_info_lease(p, end, &rde->lease, features);
 374                 if (err)
 375                         goto out_bad;
 376                 /* inode */
 377                 err = parse_reply_info_in(p, end, &rde->inode, features);
 378                 if (err < 0)
 379                         goto out_bad;
 380                 /* ceph_readdir_prepopulate() will update it */
 381                 rde->offset = 0;
 382                 i++;
 383                 num--;
 384         }
 385
 386 done:
 387         /* Skip over any unrecognized fields */
 388         *p = end;
 389         return 0;
 390
 391 bad:
 392         err = -EIO;
 393 out_bad:
 394         pr_err("problem parsing dir contents %d\n", err);
 395         return err;
 396 }
 397
 398 /*
 399  * parse fcntl F_GETLK results
 400  */
 401 static int parse_reply_info_filelock(void **p, void *end,
 402                                      struct ceph_mds_reply_info_parsed *info,
 403                                      u64 features)
 404 {
 405         if (*p + sizeof(*info->filelock_reply) > end)
 406                 goto bad;
 407
 408         info->filelock_reply = *p;
 409
 410         /* Skip over any unrecognized fields */
 411         *p = end;
 412         return 0;
 413 bad:
 414         return -EIO;
 415 }
 416
 417 /*
 418  * parse create results
 419  */
 420 static int parse_reply_info_create(void **p, void *end,
 421                                   struct ceph_mds_reply_info_parsed *info,
 422                                   u64 features)
 423 {
 424         if (features == (u64)-1 ||
 425             (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
 426                 /* Malformed reply? */
 427                 if (*p == end) {
 428                         info->has_create_ino = false;
 429                 } else {
 430                         info->has_create_ino = true;
 431                         ceph_decode_64_safe(p, end, info->ino, bad);
 432                 }
 433         } else {
 434                 if (*p != end)
 435                         goto bad;
 436         }
 437
 438         /* Skip over any unrecognized fields */
 439         *p = end;
 440         return 0;
 441 bad:
 442         return -EIO;
 443 }
 444
 445 /*
 446  * parse extra results
 447  */
 448 static int parse_reply_info_extra(void **p, void *end,
 449                                   struct ceph_mds_reply_info_parsed *info,
 450                                   u64 features)
 451 {
 452         u32 op = le32_to_cpu(info->head->op);
 453
 454         if (op == CEPH_MDS_OP_GETFILELOCK)
 455                 return parse_reply_info_filelock(p, end, info, features);
 456         else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 457                 return parse_reply_info_readdir(p, end, info, features);
 458         else if (op == CEPH_MDS_OP_CREATE)
 459                 return parse_reply_info_create(p, end, info, features);
 460         else
 461                 return -EIO;
 462 }
 463
 464 /*
 465  * parse entire mds reply
 466  */
 467 static int parse_reply_info(struct ceph_msg *msg,
 468                             struct ceph_mds_reply_info_parsed *info,
 469                             u64 features)
 470 {
 471         void *p, *end;
 472         u32 len;
 473         int err;
 474
 475         info->head = msg->front.iov_base;
 476         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 477         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 478
 479         /* trace */
 480         ceph_decode_32_safe(&p, end, len, bad);
 481         if (len > 0) {
 482                 ceph_decode_need(&p, end, len, bad);
 483                 err = parse_reply_info_trace(&p, p+len, info, features);
 484                 if (err < 0)
 485                         goto out_bad;
 486         }
 487
 488         /* extra */
 489         ceph_decode_32_safe(&p, end, len, bad);
 490         if (len > 0) {
 491                 ceph_decode_need(&p, end, len, bad);
 492                 err = parse_reply_info_extra(&p, p+len, info, features);
 493                 if (err < 0)
 494                         goto out_bad;
 495         }
 496
 497         /* snap blob */
 498         ceph_decode_32_safe(&p, end, len, bad);
 499         info->snapblob_len = len;
 500         info->snapblob = p;
 501         p += len;
 502
 503         if (p != end)
 504                 goto bad;
 505         return 0;
 506
 507 bad:
 508         err = -EIO;
 509 out_bad:
 510         pr_err("mds parse_reply err %d\n", err);
 511         return err;
 512 }
 513
 514 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 515 {
 516         if (!info->dir_entries)
 517                 return;
 518         free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 519 }
 520
 521
 522 /*
 523  * sessions
 524  */
 525 const char *ceph_session_state_name(int s)
 526 {
 527         switch (s) {
 528         case CEPH_MDS_SESSION_NEW: return "new";
 529         case CEPH_MDS_SESSION_OPENING: return "opening";
 530         case CEPH_MDS_SESSION_OPEN: return "open";
 531         case CEPH_MDS_SESSION_HUNG: return "hung";
 532         case CEPH_MDS_SESSION_CLOSING: return "closing";
 533         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 534         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 535         case CEPH_MDS_SESSION_REJECTED: return "rejected";
 536         default: return "???";
 537         }
 538 }
 539
 540 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 541 {
 542         if (refcount_inc_not_zero(&s->s_ref)) {
 543                 dout("mdsc get_session %p %d -> %d\n", s,
 544                      refcount_read(&s->s_ref)-1, refcount_read(&s->s_ref));
 545                 return s;
 546         } else {
 547                 dout("mdsc get_session %p 0 -- FAIL\n", s);
 548                 return NULL;
 549         }
 550 }
 551
 552 void ceph_put_mds_session(struct ceph_mds_session *s)
 553 {
 554         dout("mdsc put_session %p %d -> %d\n", s,
 555              refcount_read(&s->s_ref), refcount_read(&s->s_ref)-1);
 556         if (refcount_dec_and_test(&s->s_ref)) {
 557                 if (s->s_auth.authorizer)
 558                         ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 559                 kfree(s);
 560         }
 561 }
 562
 563 /*
 564  * called under mdsc->mutex
 565  */
 566 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 567                                                    int mds)
 568 {
 569         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 570                 return NULL;
 571         return get_session(mdsc->sessions[mds]);
 572 }
 573
 574 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 575 {
 576         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 577                 return false;
 578         else
 579                 return true;
 580 }
 581
 582 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 583                                        struct ceph_mds_session *s)
 584 {
 585         if (s->s_mds >= mdsc->max_sessions ||
 586             mdsc->sessions[s->s_mds] != s)
 587                 return -ENOENT;
 588         return 0;
 589 }
 590
 591 /*
 592  * create+register a new session for given mds.
 593  * called under mdsc->mutex.
 594  */
 595 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 596                                                  int mds)
 597 {
 598         struct ceph_mds_session *s;
 599
 600         if (mds >= mdsc->mdsmap->m_num_mds)
 601                 return ERR_PTR(-EINVAL);
 602
 603         s = kzalloc(sizeof(*s), GFP_NOFS);
 604         if (!s)
 605                 return ERR_PTR(-ENOMEM);
 606
 607         if (mds >= mdsc->max_sessions) {
 608                 int newmax = 1 << get_count_order(mds + 1);
 609                 struct ceph_mds_session **sa;
 610
 611                 dout("%s: realloc to %d\n", __func__, newmax);
 612                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 613                 if (!sa)
 614                         goto fail_realloc;
 615                 if (mdsc->sessions) {
 616                         memcpy(sa, mdsc->sessions,
 617                                mdsc->max_sessions * sizeof(void *));
 618                         kfree(mdsc->sessions);
 619                 }
 620                 mdsc->sessions = sa;
 621                 mdsc->max_sessions = newmax;
 622         }
 623
 624         dout("%s: mds%d\n", __func__, mds);
 625         s->s_mdsc = mdsc;
 626         s->s_mds = mds;
 627         s->s_state = CEPH_MDS_SESSION_NEW;
 628         s->s_ttl = 0;
 629         s->s_seq = 0;
 630         mutex_init(&s->s_mutex);
 631
 632         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 633
 634         spin_lock_init(&s->s_gen_ttl_lock);
 635         s->s_cap_gen = 1;
 636         s->s_cap_ttl = jiffies - 1;
 637
 638         spin_lock_init(&s->s_cap_lock);
 639         s->s_renew_requested = 0;
 640         s->s_renew_seq = 0;
 641         INIT_LIST_HEAD(&s->s_caps);
 642         s->s_nr_caps = 0;
 643         refcount_set(&s->s_ref, 1);
 644         INIT_LIST_HEAD(&s->s_waiting);
 645         INIT_LIST_HEAD(&s->s_unsafe);
 646         s->s_num_cap_releases = 0;
 647         s->s_cap_reconnect = 0;
 648         s->s_cap_iterator = NULL;
 649         INIT_LIST_HEAD(&s->s_cap_releases);
 650         INIT_WORK(&s->s_cap_release_work, ceph_cap_release_work);
 651
 652         INIT_LIST_HEAD(&s->s_cap_flushing);
 653
 654         mdsc->sessions[mds] = s;
 655         atomic_inc(&mdsc->num_sessions);
 656         refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 657
 658         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 659                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 660
 661         return s;
 662
 663 fail_realloc:
 664         kfree(s);
 665         return ERR_PTR(-ENOMEM);
 666 }
 667
 668 /*
 669  * called under mdsc->mutex
 670  */
 671 static void __unregister_session(struct ceph_mds_client *mdsc,
 672                                struct ceph_mds_session *s)
 673 {
 674         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 675         BUG_ON(mdsc->sessions[s->s_mds] != s);
 676         mdsc->sessions[s->s_mds] = NULL;
 677         s->s_state = 0;
 678         ceph_con_close(&s->s_con);
 679         ceph_put_mds_session(s);
 680         atomic_dec(&mdsc->num_sessions);
 681 }
 682
 683 /*
 684  * drop session refs in request.
 685  *
 686  * should be last request ref, or hold mdsc->mutex
 687  */
 688 static void put_request_session(struct ceph_mds_request *req)
 689 {
 690         if (req->r_session) {
 691                 ceph_put_mds_session(req->r_session);
 692                 req->r_session = NULL;
 693         }
 694 }
 695
 696 void ceph_mdsc_release_request(struct kref *kref)
 697 {
 698         struct ceph_mds_request *req = container_of(kref,
 699                                                     struct ceph_mds_request,
 700                                                     r_kref);
 701         destroy_reply_info(&req->r_reply_info);
 702         if (req->r_request)
 703                 ceph_msg_put(req->r_request);
 704         if (req->r_reply)
 705                 ceph_msg_put(req->r_reply);
 706         if (req->r_inode) {
 707                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 708                 /* avoid calling iput_final() in mds dispatch threads */
 709                 ceph_async_iput(req->r_inode);
 710         }
 711         if (req->r_parent)
 712                 ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
 713         ceph_async_iput(req->r_target_inode);
 714         if (req->r_dentry)
 715                 dput(req->r_dentry);
 716         if (req->r_old_dentry)
 717                 dput(req->r_old_dentry);
 718         if (req->r_old_dentry_dir) {
 719                 /*
 720                  * track (and drop pins for) r_old_dentry_dir
 721                  * separately, since r_old_dentry's d_parent may have
 722                  * changed between the dir mutex being dropped and
 723                  * this request being freed.
 724                  */
 725                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 726                                   CEPH_CAP_PIN);
 727                 ceph_async_iput(req->r_old_dentry_dir);
 728         }
 729         kfree(req->r_path1);
 730         kfree(req->r_path2);
 731         if (req->r_pagelist)
 732                 ceph_pagelist_release(req->r_pagelist);
 733         put_request_session(req);
 734         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 735         WARN_ON_ONCE(!list_empty(&req->r_wait));
 736         kfree(req);
 737 }
 738
 739 DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 740
 741 /*
 742  * lookup session, bump ref if found.
 743  *
 744  * called under mdsc->mutex.
 745  */
 746 static struct ceph_mds_request *
 747 lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 748 {
 749         struct ceph_mds_request *req;
 750
 751         req = lookup_request(&mdsc->request_tree, tid);
 752         if (req)
 753                 ceph_mdsc_get_request(req);
 754
 755         return req;
 756 }
 757
 758 /*
 759  * Register an in-flight request, and assign a tid.  Link to directory
 760  * are modifying (if any).
 761  *
 762  * Called under mdsc->mutex.
 763  */
 764 static void __register_request(struct ceph_mds_client *mdsc,
 765                                struct ceph_mds_request *req,
 766                                struct inode *dir)
 767 {
 768         int ret = 0;
 769
 770         req->r_tid = ++mdsc->last_tid;
 771         if (req->r_num_caps) {
 772                 ret = ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 773                                         req->r_num_caps);
 774                 if (ret < 0) {
 775                         pr_err("__register_request %p "
 776                                "failed to reserve caps: %d\n", req, ret);
 777                         /* set req->r_err to fail early from __do_request */
 778                         req->r_err = ret;
 779                         return;
 780                 }
 781         }
 782         dout("__register_request %p tid %lld\n", req, req->r_tid);
 783         ceph_mdsc_get_request(req);
 784         insert_request(&mdsc->request_tree, req);
 785
 786         req->r_uid = current_fsuid();
 787         req->r_gid = current_fsgid();
 788
 789         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 790                 mdsc->oldest_tid = req->r_tid;
 791
 792         if (dir) {
 793                 ihold(dir);
 794                 req->r_unsafe_dir = dir;
 795         }
 796 }
 797
 798 static void __unregister_request(struct ceph_mds_client *mdsc,
 799                                  struct ceph_mds_request *req)
 800 {
 801         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 802
 803         /* Never leave an unregistered request on an unsafe list! */
 804         list_del_init(&req->r_unsafe_item);
 805
 806         if (req->r_tid == mdsc->oldest_tid) {
 807                 struct rb_node *p = rb_next(&req->r_node);
 808                 mdsc->oldest_tid = 0;
 809                 while (p) {
 810                         struct ceph_mds_request *next_req =
 811                                 rb_entry(p, struct ceph_mds_request, r_node);
 812                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 813                                 mdsc->oldest_tid = next_req->r_tid;
 814                                 break;
 815                         }
 816                         p = rb_next(p);
 817                 }
 818         }
 819
 820         erase_request(&mdsc->request_tree, req);
 821
 822         if (req->r_unsafe_dir  &&
 823             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 824                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 825                 spin_lock(&ci->i_unsafe_lock);
 826                 list_del_init(&req->r_unsafe_dir_item);
 827                 spin_unlock(&ci->i_unsafe_lock);
 828         }
 829         if (req->r_target_inode &&
 830             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 831                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 832                 spin_lock(&ci->i_unsafe_lock);
 833                 list_del_init(&req->r_unsafe_target_item);
 834                 spin_unlock(&ci->i_unsafe_lock);
 835         }
 836
 837         if (req->r_unsafe_dir) {
 838                 /* avoid calling iput_final() in mds dispatch threads */
 839                 ceph_async_iput(req->r_unsafe_dir);
 840                 req->r_unsafe_dir = NULL;
 841         }
 842
 843         complete_all(&req->r_safe_completion);
 844
 845         ceph_mdsc_put_request(req);
 846 }
 847
 848 /*
 849  * Walk back up the dentry tree until we hit a dentry representing a
 850  * non-snapshot inode. We do this using the rcu_read_lock (which must be held
 851  * when calling this) to ensure that the objects won't disappear while we're
 852  * working with them. Once we hit a candidate dentry, we attempt to take a
 853  * reference to it, and return that as the result.
 854  */
 855 static struct inode *get_nonsnap_parent(struct dentry *dentry)
 856 {
 857         struct inode *inode = NULL;
 858
 859         while (dentry && !IS_ROOT(dentry)) {
 860                 inode = d_inode_rcu(dentry);
 861                 if (!inode || ceph_snap(inode) == CEPH_NOSNAP)
 862                         break;
 863                 dentry = dentry->d_parent;
 864         }
 865         if (inode)
 866                 inode = igrab(inode);
 867         return inode;
 868 }
 869
 870 /*
 871  * Choose mds to send request to next.  If there is a hint set in the
 872  * request (e.g., due to a prior forward hint from the mds), use that.
 873  * Otherwise, consult frag tree and/or caps to identify the
 874  * appropriate mds.  If all else fails, choose randomly.
 875  *
 876  * Called under mdsc->mutex.
 877  */
 878 static int __choose_mds(struct ceph_mds_client *mdsc,
 879                         struct ceph_mds_request *req)
 880 {
 881         struct inode *inode;
 882         struct ceph_inode_info *ci;
 883         struct ceph_cap *cap;
 884         int mode = req->r_direct_mode;
 885         int mds = -1;
 886         u32 hash = req->r_direct_hash;
 887         bool is_hash = test_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
 888
 889         /*
 890          * is there a specific mds we should try?  ignore hint if we have
 891          * no session and the mds is not up (active or recovering).
 892          */
 893         if (req->r_resend_mds >= 0 &&
 894             (__have_session(mdsc, req->r_resend_mds) ||
 895              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 896                 dout("choose_mds using resend_mds mds%d\n",
 897                      req->r_resend_mds);
 898                 return req->r_resend_mds;
 899         }
 900
 901         if (mode == USE_RANDOM_MDS)
 902                 goto random;
 903
 904         inode = NULL;
 905         if (req->r_inode) {
 906                 if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
 907                         inode = req->r_inode;
 908                         ihold(inode);
 909                 } else {
 910                         /* req->r_dentry is non-null for LSSNAP request */
 911                         rcu_read_lock();
 912                         inode = get_nonsnap_parent(req->r_dentry);
 913                         rcu_read_unlock();
 914                         dout("__choose_mds using snapdir's parent %p\n", inode);
 915                 }
 916         } else if (req->r_dentry) {
 917                 /* ignore race with rename; old or new d_parent is okay */
 918                 struct dentry *parent;
 919                 struct inode *dir;
 920
 921                 rcu_read_lock();
 922                 parent = READ_ONCE(req->r_dentry->d_parent);
 923                 dir = req->r_parent ? : d_inode_rcu(parent);
 924
 925                 if (!dir || dir->i_sb != mdsc->fsc->sb) {
 926                         /*  not this fs or parent went negative */
 927                         inode = d_inode(req->r_dentry);
 928                         if (inode)
 929                                 ihold(inode);
 930                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 931                         /* direct snapped/virtual snapdir requests
 932                          * based on parent dir inode */
 933                         inode = get_nonsnap_parent(parent);
 934                         dout("__choose_mds using nonsnap parent %p\n", inode);
 935                 } else {
 936                         /* dentry target */
 937                         inode = d_inode(req->r_dentry);
 938                         if (!inode || mode == USE_AUTH_MDS) {
 939                                 /* dir + name */
 940                                 inode = igrab(dir);
 941                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 942                                 is_hash = true;
 943                         } else {
 944                                 ihold(inode);
 945                         }
 946                 }
 947                 rcu_read_unlock();
 948         }
 949
 950         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 951              (int)hash, mode);
 952         if (!inode)
 953                 goto random;
 954         ci = ceph_inode(inode);
 955
 956         if (is_hash && S_ISDIR(inode->i_mode)) {
 957                 struct ceph_inode_frag frag;
 958                 int found;
 959
 960                 ceph_choose_frag(ci, hash, &frag, &found);
 961                 if (found) {
 962                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 963                                 u8 r;
 964
 965                                 /* choose a random replica */
 966                                 get_random_bytes(&r, 1);
 967                                 r %= frag.ndist;
 968                                 mds = frag.dist[r];
 969                                 dout("choose_mds %p %llx.%llx "
 970                                      "frag %u mds%d (%d/%d)\n",
 971                                      inode, ceph_vinop(inode),
 972                                      frag.frag, mds,
 973                                      (int)r, frag.ndist);
 974                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 975                                     CEPH_MDS_STATE_ACTIVE)
 976                                         goto out;
 977                         }
 978
 979                         /* since this file/dir wasn't known to be
 980                          * replicated, then we want to look for the
 981                          * authoritative mds. */
 982                         mode = USE_AUTH_MDS;
 983                         if (frag.mds >= 0) {
 984                                 /* choose auth mds */
 985                                 mds = frag.mds;
 986                                 dout("choose_mds %p %llx.%llx "
 987                                      "frag %u mds%d (auth)\n",
 988                                      inode, ceph_vinop(inode), frag.frag, mds);
 989                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 990                                     CEPH_MDS_STATE_ACTIVE)
 991                                         goto out;
 992                         }
 993                 }
 994         }
 995
 996         spin_lock(&ci->i_ceph_lock);
 997         cap = NULL;
 998         if (mode == USE_AUTH_MDS)
 999                 cap = ci->i_auth_cap;
1000         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
1001                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
1002         if (!cap) {
1003                 spin_unlock(&ci->i_ceph_lock);
1004                 ceph_async_iput(inode);
1005                 goto random;
1006         }
1007         mds = cap->session->s_mds;
1008         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
1009              inode, ceph_vinop(inode), mds,
1010              cap == ci->i_auth_cap ? "auth " : "", cap);
1011         spin_unlock(&ci->i_ceph_lock);
1012 out:
1013         /* avoid calling iput_final() while holding mdsc->mutex or
1014          * in mds dispatch threads */
1015         ceph_async_iput(inode);
1016         return mds;
1017
1018 random:
1019         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
1020         dout("choose_mds chose random mds%d\n", mds);
1021         return mds;
1022 }
1023
1024
1025 /*
1026  * session messages
1027  */
1028 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
1029 {
1030         struct ceph_msg *msg;
1031         struct ceph_mds_session_head *h;
1032
1033         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
1034                            false);
1035         if (!msg) {
1036                 pr_err("create_session_msg ENOMEM creating msg\n");
1037                 return NULL;
1038         }
1039         h = msg->front.iov_base;
1040         h->op = cpu_to_le32(op);
1041         h->seq = cpu_to_le64(seq);
1042
1043         return msg;
1044 }
1045
1046 static void encode_supported_features(void **p, void *end)
1047 {
1048         static const unsigned char bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
1049         static const size_t count = ARRAY_SIZE(bits);
1050
1051         if (count > 0) {
1052                 size_t i;
1053                 size_t size = ((size_t)bits[count - 1] + 64) / 64 * 8;
1054
1055                 BUG_ON(*p + 4 + size > end);
1056                 ceph_encode_32(p, size);
1057                 memset(*p, 0, size);
1058                 for (i = 0; i < count; i++)
1059                         ((unsigned char*)(*p))[i / 8] |= 1 << (bits[i] % 8);
1060                 *p += size;
1061         } else {
1062                 BUG_ON(*p + 4 > end);
1063                 ceph_encode_32(p, 0);
1064         }
1065 }
1066
1067 /*
1068  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
1069  * to include additional client metadata fields.
1070  */
1071 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
1072 {
1073         struct ceph_msg *msg;
1074         struct ceph_mds_session_head *h;
1075         int i = -1;
1076         int extra_bytes = 0;
1077         int metadata_key_count = 0;
1078         struct ceph_options *opt = mdsc->fsc->client->options;
1079         struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
1080         void *p, *end;
1081
1082         const char* metadata[][2] = {
1083                 {"hostname", mdsc->nodename},
1084                 {"kernel_version", init_utsname()->release},
1085                 {"entity_id", opt->name ? : ""},
1086                 {"root", fsopt->server_path ? : "/"},
1087                 {NULL, NULL}
1088         };
1089
1090         /* Calculate serialized length of metadata */
1091         extra_bytes = 4;  /* map length */
1092         for (i = 0; metadata[i][0]; ++i) {
1093                 extra_bytes += 8 + strlen(metadata[i][0]) +
1094                         strlen(metadata[i][1]);
1095                 metadata_key_count++;
1096         }
1097         /* supported feature */
1098         extra_bytes += 4 + 8;
1099
1100         /* Allocate the message */
1101         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + extra_bytes,
1102                            GFP_NOFS, false);
1103         if (!msg) {
1104                 pr_err("create_session_msg ENOMEM creating msg\n");
1105                 return NULL;
1106         }
1107         p = msg->front.iov_base;
1108         end = p + msg->front.iov_len;
1109
1110         h = p;
1111         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
1112         h->seq = cpu_to_le64(seq);
1113
1114         /*
1115          * Serialize client metadata into waiting buffer space, using
1116          * the format that userspace expects for map<string, string>
1117          *
1118          * ClientSession messages with metadata are v2
1119          */
1120         msg->hdr.version = cpu_to_le16(3);
1121         msg->hdr.compat_version = cpu_to_le16(1);
1122
1123         /* The write pointer, following the session_head structure */
1124         p += sizeof(*h);
1125
1126         /* Number of entries in the map */
1127         ceph_encode_32(&p, metadata_key_count);
1128
1129         /* Two length-prefixed strings for each entry in the map */
1130         for (i = 0; metadata[i][0]; ++i) {
1131                 size_t const key_len = strlen(metadata[i][0]);
1132                 size_t const val_len = strlen(metadata[i][1]);
1133
1134                 ceph_encode_32(&p, key_len);
1135                 memcpy(p, metadata[i][0], key_len);
1136                 p += key_len;
1137                 ceph_encode_32(&p, val_len);
1138                 memcpy(p, metadata[i][1], val_len);
1139                 p += val_len;
1140         }
1141
1142         encode_supported_features(&p, end);
1143         msg->front.iov_len = p - msg->front.iov_base;
1144         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1145
1146         return msg;
1147 }
1148
1149 /*
1150  * send session open request.
1151  *
1152  * called under mdsc->mutex
1153  */
1154 static int __open_session(struct ceph_mds_client *mdsc,
1155                           struct ceph_mds_session *session)
1156 {
1157         struct ceph_msg *msg;
1158         int mstate;
1159         int mds = session->s_mds;
1160
1161         /* wait for mds to go active? */
1162         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
1163         dout("open_session to mds%d (%s)\n", mds,
1164              ceph_mds_state_name(mstate));
1165         session->s_state = CEPH_MDS_SESSION_OPENING;
1166         session->s_renew_requested = jiffies;
1167
1168         /* send connect message */
1169         msg = create_session_open_msg(mdsc, session->s_seq);
1170         if (!msg)
1171                 return -ENOMEM;
1172         ceph_con_send(&session->s_con, msg);
1173         return 0;
1174 }
1175
1176 /*
1177  * open sessions for any export targets for the given mds
1178  *
1179  * called under mdsc->mutex
1180  */
1181 static struct ceph_mds_session *
1182 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
1183 {
1184         struct ceph_mds_session *session;
1185
1186         session = __ceph_lookup_mds_session(mdsc, target);
1187         if (!session) {
1188                 session = register_session(mdsc, target);
1189                 if (IS_ERR(session))
1190                         return session;
1191         }
1192         if (session->s_state == CEPH_MDS_SESSION_NEW ||
1193             session->s_state == CEPH_MDS_SESSION_CLOSING)
1194                 __open_session(mdsc, session);
1195
1196         return session;
1197 }
1198
1199 struct ceph_mds_session *
1200 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
1201 {
1202         struct ceph_mds_session *session;
1203
1204         dout("open_export_target_session to mds%d\n", target);
1205
1206         mutex_lock(&mdsc->mutex);
1207         session = __open_export_target_session(mdsc, target);
1208         mutex_unlock(&mdsc->mutex);
1209
1210         return session;
1211 }
1212
1213 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
1214                                           struct ceph_mds_session *session)
1215 {
1216         struct ceph_mds_info *mi;
1217         struct ceph_mds_session *ts;
1218         int i, mds = session->s_mds;
1219
1220         if (mds >= mdsc->mdsmap->m_num_mds)
1221                 return;
1222
1223         mi = &mdsc->mdsmap->m_info[mds];
1224         dout("open_export_target_sessions for mds%d (%d targets)\n",
1225              session->s_mds, mi->num_export_targets);
1226
1227         for (i = 0; i < mi->num_export_targets; i++) {
1228                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1229                 if (!IS_ERR(ts))
1230                         ceph_put_mds_session(ts);
1231         }
1232 }
1233
1234 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1235                                            struct ceph_mds_session *session)
1236 {
1237         mutex_lock(&mdsc->mutex);
1238         __open_export_target_sessions(mdsc, session);
1239         mutex_unlock(&mdsc->mutex);
1240 }
1241
1242 /*
1243  * session caps
1244  */
1245
1246 static void detach_cap_releases(struct ceph_mds_session *session,
1247                                 struct list_head *target)
1248 {
1249         lockdep_assert_held(&session->s_cap_lock);
1250
1251         list_splice_init(&session->s_cap_releases, target);
1252         session->s_num_cap_releases = 0;
1253         dout("dispose_cap_releases mds%d\n", session->s_mds);
1254 }
1255
1256 static void dispose_cap_releases(struct ceph_mds_client *mdsc,
1257                                  struct list_head *dispose)
1258 {
1259         while (!list_empty(dispose)) {
1260                 struct ceph_cap *cap;
1261                 /* zero out the in-progress message */
1262                 cap = list_first_entry(dispose, struct ceph_cap, session_caps);
1263                 list_del(&cap->session_caps);
1264                 ceph_put_cap(mdsc, cap);
1265         }
1266 }
1267
1268 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1269                                      struct ceph_mds_session *session)
1270 {
1271         struct ceph_mds_request *req;
1272         struct rb_node *p;
1273         struct ceph_inode_info *ci;
1274
1275         dout("cleanup_session_requests mds%d\n", session->s_mds);
1276         mutex_lock(&mdsc->mutex);
1277         while (!list_empty(&session->s_unsafe)) {
1278                 req = list_first_entry(&session->s_unsafe,
1279                                        struct ceph_mds_request, r_unsafe_item);
1280                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1281                                     req->r_tid);
1282                 if (req->r_target_inode) {
1283                         /* dropping unsafe change of inode's attributes */
1284                         ci = ceph_inode(req->r_target_inode);
1285                         errseq_set(&ci->i_meta_err, -EIO);
1286                 }
1287                 if (req->r_unsafe_dir) {
1288                         /* dropping unsafe directory operation */
1289                         ci = ceph_inode(req->r_unsafe_dir);
1290                         errseq_set(&ci->i_meta_err, -EIO);
1291                 }
1292                 __unregister_request(mdsc, req);
1293         }
1294         /* zero r_attempts, so kick_requests() will re-send requests */
1295         p = rb_first(&mdsc->request_tree);
1296         while (p) {
1297                 req = rb_entry(p, struct ceph_mds_request, r_node);
1298                 p = rb_next(p);
1299                 if (req->r_session &&
1300                     req->r_session->s_mds == session->s_mds)
1301                         req->r_attempts = 0;
1302         }
1303         mutex_unlock(&mdsc->mutex);
1304 }
1305
1306 /*
1307  * Helper to safely iterate over all caps associated with a session, with
1308  * special care taken to handle a racing __ceph_remove_cap().
1309  *
1310  * Caller must hold session s_mutex.
1311  */
1312 int ceph_iterate_session_caps(struct ceph_mds_session *session,
1313                               int (*cb)(struct inode *, struct ceph_cap *,
1314                                         void *), void *arg)
1315 {
1316         struct list_head *p;
1317         struct ceph_cap *cap;
1318         struct inode *inode, *last_inode = NULL;
1319         struct ceph_cap *old_cap = NULL;
1320         int ret;
1321
1322         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1323         spin_lock(&session->s_cap_lock);
1324         p = session->s_caps.next;
1325         while (p != &session->s_caps) {
1326                 cap = list_entry(p, struct ceph_cap, session_caps);
1327                 inode = igrab(&cap->ci->vfs_inode);
1328                 if (!inode) {
1329                         p = p->next;
1330                         continue;
1331                 }
1332                 session->s_cap_iterator = cap;
1333                 spin_unlock(&session->s_cap_lock);
1334
1335                 if (last_inode) {
1336                         /* avoid calling iput_final() while holding
1337                          * s_mutex or in mds dispatch threads */
1338                         ceph_async_iput(last_inode);
1339                         last_inode = NULL;
1340                 }
1341                 if (old_cap) {
1342                         ceph_put_cap(session->s_mdsc, old_cap);
1343                         old_cap = NULL;
1344                 }
1345
1346                 ret = cb(inode, cap, arg);
1347                 last_inode = inode;
1348
1349                 spin_lock(&session->s_cap_lock);
1350                 p = p->next;
1351                 if (!cap->ci) {
1352                         dout("iterate_session_caps  finishing cap %p removal\n",
1353                              cap);
1354                         BUG_ON(cap->session != session);
1355                         cap->session = NULL;
1356                         list_del_init(&cap->session_caps);
1357                         session->s_nr_caps--;
1358                         if (cap->queue_release)
1359                                 __ceph_queue_cap_release(session, cap);
1360                         else
1361                                 old_cap = cap;  /* put_cap it w/o locks held */
1362                 }
1363                 if (ret < 0)
1364                         goto out;
1365         }
1366         ret = 0;
1367 out:
1368         session->s_cap_iterator = NULL;
1369         spin_unlock(&session->s_cap_lock);
1370
1371         ceph_async_iput(last_inode);
1372         if (old_cap)
1373                 ceph_put_cap(session->s_mdsc, old_cap);
1374
1375         return ret;
1376 }
1377
1378 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1379                                   void *arg)
1380 {
1381         struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1382         struct ceph_inode_info *ci = ceph_inode(inode);
1383         LIST_HEAD(to_remove);
1384         bool dirty_dropped = false;
1385         bool invalidate = false;
1386
1387         dout("removing cap %p, ci is %p, inode is %p\n",
1388              cap, ci, &ci->vfs_inode);
1389         spin_lock(&ci->i_ceph_lock);
1390         if (cap->mds_wanted | cap->issued)
1391                 ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1392         __ceph_remove_cap(cap, false);
1393         if (!ci->i_auth_cap) {
1394                 struct ceph_cap_flush *cf;
1395                 struct ceph_mds_client *mdsc = fsc->mdsc;
1396
1397                 if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
1398                         if (inode->i_data.nrpages > 0)
1399                                 invalidate = true;
1400                         if (ci->i_wrbuffer_ref > 0)
1401                                 mapping_set_error(&inode->i_data, -EIO);
1402                 }
1403
1404                 while (!list_empty(&ci->i_cap_flush_list)) {
1405                         cf = list_first_entry(&ci->i_cap_flush_list,
1406                                               struct ceph_cap_flush, i_list);
1407                         list_move(&cf->i_list, &to_remove);
1408                 }
1409
1410                 spin_lock(&mdsc->cap_dirty_lock);
1411
1412                 list_for_each_entry(cf, &to_remove, i_list)
1413                         list_del(&cf->g_list);
1414
1415                 if (!list_empty(&ci->i_dirty_item)) {
1416                         pr_warn_ratelimited(
1417                                 " dropping dirty %s state for %p %lld\n",
1418                                 ceph_cap_string(ci->i_dirty_caps),
1419                                 inode, ceph_ino(inode));
1420                         ci->i_dirty_caps = 0;
1421                         list_del_init(&ci->i_dirty_item);
1422                         dirty_dropped = true;
1423                 }
1424                 if (!list_empty(&ci->i_flushing_item)) {
1425                         pr_warn_ratelimited(
1426                                 " dropping dirty+flushing %s state for %p %lld\n",
1427                                 ceph_cap_string(ci->i_flushing_caps),
1428                                 inode, ceph_ino(inode));
1429                         ci->i_flushing_caps = 0;
1430                         list_del_init(&ci->i_flushing_item);
1431                         mdsc->num_cap_flushing--;
1432                         dirty_dropped = true;
1433                 }
1434                 spin_unlock(&mdsc->cap_dirty_lock);
1435
1436                 if (dirty_dropped) {
1437                         errseq_set(&ci->i_meta_err, -EIO);
1438
1439                         if (ci->i_wrbuffer_ref_head == 0 &&
1440                             ci->i_wr_ref == 0 &&
1441                             ci->i_dirty_caps == 0 &&
1442                             ci->i_flushing_caps == 0) {
1443                                 ceph_put_snap_context(ci->i_head_snapc);
1444                                 ci->i_head_snapc = NULL;
1445                         }
1446                 }
1447
1448                 if (atomic_read(&ci->i_filelock_ref) > 0) {
1449                         /* make further file lock syscall return -EIO */
1450                         ci->i_ceph_flags |= CEPH_I_ERROR_FILELOCK;
1451                         pr_warn_ratelimited(" dropping file locks for %p %lld\n",
1452                                             inode, ceph_ino(inode));
1453                 }
1454
1455                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1456                         list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
1457                         ci->i_prealloc_cap_flush = NULL;
1458                 }
1459         }
1460         spin_unlock(&ci->i_ceph_lock);
1461         while (!list_empty(&to_remove)) {
1462                 struct ceph_cap_flush *cf;
1463                 cf = list_first_entry(&to_remove,
1464                                       struct ceph_cap_flush, i_list);
1465                 list_del(&cf->i_list);
1466                 ceph_free_cap_flush(cf);
1467         }
1468
1469         wake_up_all(&ci->i_cap_wq);
1470         if (invalidate)
1471                 ceph_queue_invalidate(inode);
1472         if (dirty_dropped)
1473                 iput(inode);
1474         return 0;
1475 }
1476
1477 /*
1478  * caller must hold session s_mutex
1479  */
1480 static void remove_session_caps(struct ceph_mds_session *session)
1481 {
1482         struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1483         struct super_block *sb = fsc->sb;
1484         LIST_HEAD(dispose);
1485
1486         dout("remove_session_caps on %p\n", session);
1487         ceph_iterate_session_caps(session, remove_session_caps_cb, fsc);
1488
1489         wake_up_all(&fsc->mdsc->cap_flushing_wq);
1490
1491         spin_lock(&session->s_cap_lock);
1492         if (session->s_nr_caps > 0) {
1493                 struct inode *inode;
1494                 struct ceph_cap *cap, *prev = NULL;
1495                 struct ceph_vino vino;
1496                 /*
1497                  * iterate_session_caps() skips inodes that are being
1498                  * deleted, we need to wait until deletions are complete.
1499                  * __wait_on_freeing_inode() is designed for the job,
1500                  * but it is not exported, so use lookup inode function
1501                  * to access it.
1502                  */
1503                 while (!list_empty(&session->s_caps)) {
1504                         cap = list_entry(session->s_caps.next,
1505                                          struct ceph_cap, session_caps);
1506                         if (cap == prev)
1507                                 break;
1508                         prev = cap;
1509                         vino = cap->ci->i_vino;
1510                         spin_unlock(&session->s_cap_lock);
1511
1512                         inode = ceph_find_inode(sb, vino);
1513                          /* avoid calling iput_final() while holding s_mutex */
1514                         ceph_async_iput(inode);
1515
1516                         spin_lock(&session->s_cap_lock);
1517                 }
1518         }
1519
1520         // drop cap expires and unlock s_cap_lock
1521         detach_cap_releases(session, &dispose);
1522
1523         BUG_ON(session->s_nr_caps > 0);
1524         BUG_ON(!list_empty(&session->s_cap_flushing));
1525         spin_unlock(&session->s_cap_lock);
1526         dispose_cap_releases(session->s_mdsc, &dispose);
1527 }
1528
1529 enum {
1530         RECONNECT,
1531         RENEWCAPS,
1532         FORCE_RO,
1533 };
1534
1535 /*
1536  * wake up any threads waiting on this session's caps.  if the cap is
1537  * old (didn't get renewed on the client reconnect), remove it now.
1538  *
1539  * caller must hold s_mutex.
1540  */
1541 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1542                               void *arg)
1543 {
1544         struct ceph_inode_info *ci = ceph_inode(inode);
1545         unsigned long ev = (unsigned long)arg;
1546
1547         if (ev == RECONNECT) {
1548                 spin_lock(&ci->i_ceph_lock);
1549                 ci->i_wanted_max_size = 0;
1550                 ci->i_requested_max_size = 0;
1551                 spin_unlock(&ci->i_ceph_lock);
1552         } else if (ev == RENEWCAPS) {
1553                 if (cap->cap_gen < cap->session->s_cap_gen) {
1554                         /* mds did not re-issue stale cap */
1555                         spin_lock(&ci->i_ceph_lock);
1556                         cap->issued = cap->implemented = CEPH_CAP_PIN;
1557                         /* make sure mds knows what we want */
1558                         if (__ceph_caps_file_wanted(ci) & ~cap->mds_wanted)
1559                                 ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1560                         spin_unlock(&ci->i_ceph_lock);
1561                 }
1562         } else if (ev == FORCE_RO) {
1563         }
1564         wake_up_all(&ci->i_cap_wq);
1565         return 0;
1566 }
1567
1568 static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
1569 {
1570         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1571         ceph_iterate_session_caps(session, wake_up_session_cb,
1572                                   (void *)(unsigned long)ev);
1573 }
1574
1575 /*
1576  * Send periodic message to MDS renewing all currently held caps.  The
1577  * ack will reset the expiration for all caps from this session.
1578  *
1579  * caller holds s_mutex
1580  */
1581 static int send_renew_caps(struct ceph_mds_client *mdsc,
1582                            struct ceph_mds_session *session)
1583 {
1584         struct ceph_msg *msg;
1585         int state;
1586
1587         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1588             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1589                 pr_info("mds%d caps stale\n", session->s_mds);
1590         session->s_renew_requested = jiffies;
1591
1592         /* do not try to renew caps until a recovering mds has reconnected
1593          * with its clients. */
1594         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1595         if (state < CEPH_MDS_STATE_RECONNECT) {
1596                 dout("send_renew_caps ignoring mds%d (%s)\n",
1597                      session->s_mds, ceph_mds_state_name(state));
1598                 return 0;
1599         }
1600
1601         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1602                 ceph_mds_state_name(state));
1603         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1604                                  ++session->s_renew_seq);
1605         if (!msg)
1606                 return -ENOMEM;
1607         ceph_con_send(&session->s_con, msg);
1608         return 0;
1609 }
1610
1611 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1612                              struct ceph_mds_session *session, u64 seq)
1613 {
1614         struct ceph_msg *msg;
1615
1616         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1617              session->s_mds, ceph_session_state_name(session->s_state), seq);
1618         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1619         if (!msg)
1620                 return -ENOMEM;
1621         ceph_con_send(&session->s_con, msg);
1622         return 0;
1623 }
1624
1625
1626 /*
1627  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1628  *
1629  * Called under session->s_mutex
1630  */
1631 static void renewed_caps(struct ceph_mds_client *mdsc,
1632                          struct ceph_mds_session *session, int is_renew)
1633 {
1634         int was_stale;
1635         int wake = 0;
1636
1637         spin_lock(&session->s_cap_lock);
1638         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1639
1640         session->s_cap_ttl = session->s_renew_requested +
1641                 mdsc->mdsmap->m_session_timeout*HZ;
1642
1643         if (was_stale) {
1644                 if (time_before(jiffies, session->s_cap_ttl)) {
1645                         pr_info("mds%d caps renewed\n", session->s_mds);
1646                         wake = 1;
1647                 } else {
1648                         pr_info("mds%d caps still stale\n", session->s_mds);
1649                 }
1650         }
1651         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1652              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1653              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1654         spin_unlock(&session->s_cap_lock);
1655
1656         if (wake)
1657                 wake_up_session_caps(session, RENEWCAPS);
1658 }
1659
1660 /*
1661  * send a session close request
1662  */
1663 static int request_close_session(struct ceph_mds_client *mdsc,
1664                                  struct ceph_mds_session *session)
1665 {
1666         struct ceph_msg *msg;
1667
1668         dout("request_close_session mds%d state %s seq %lld\n",
1669              session->s_mds, ceph_session_state_name(session->s_state),
1670              session->s_seq);
1671         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1672         if (!msg)
1673                 return -ENOMEM;
1674         ceph_con_send(&session->s_con, msg);
1675         return 1;
1676 }
1677
1678 /*
1679  * Called with s_mutex held.
1680  */
1681 static int __close_session(struct ceph_mds_client *mdsc,
1682                          struct ceph_mds_session *session)
1683 {
1684         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1685                 return 0;
1686         session->s_state = CEPH_MDS_SESSION_CLOSING;
1687         return request_close_session(mdsc, session);
1688 }
1689
1690 static bool drop_negative_children(struct dentry *dentry)
1691 {
1692         struct dentry *child;
1693         bool all_negative = true;
1694
1695         if (!d_is_dir(dentry))
1696                 goto out;
1697
1698         spin_lock(&dentry->d_lock);
1699         list_for_each_entry(child, &dentry->d_subdirs, d_child) {
1700                 if (d_really_is_positive(child)) {
1701                         all_negative = false;
1702                         break;
1703                 }
1704         }
1705         spin_unlock(&dentry->d_lock);
1706
1707         if (all_negative)
1708                 shrink_dcache_parent(dentry);
1709 out:
1710         return all_negative;
1711 }
1712
1713 /*
1714  * Trim old(er) caps.
1715  *
1716  * Because we can't cache an inode without one or more caps, we do
1717  * this indirectly: if a cap is unused, we prune its aliases, at which
1718  * point the inode will hopefully get dropped to.
1719  *
1720  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1721  * memory pressure from the MDS, though, so it needn't be perfect.
1722  */
1723 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1724 {
1725         int *remaining = arg;
1726         struct ceph_inode_info *ci = ceph_inode(inode);
1727         int used, wanted, oissued, mine;
1728
1729         if (*remaining <= 0)
1730                 return -1;
1731
1732         spin_lock(&ci->i_ceph_lock);
1733         mine = cap->issued | cap->implemented;
1734         used = __ceph_caps_used(ci);
1735         wanted = __ceph_caps_file_wanted(ci);
1736         oissued = __ceph_caps_issued_other(ci, cap);
1737
1738         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1739              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1740              ceph_cap_string(used), ceph_cap_string(wanted));
1741         if (cap == ci->i_auth_cap) {
1742                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1743                     !list_empty(&ci->i_cap_snaps))
1744                         goto out;
1745                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1746                         goto out;
1747                 /* Note: it's possible that i_filelock_ref becomes non-zero
1748                  * after dropping auth caps. It doesn't hurt because reply
1749                  * of lock mds request will re-add auth caps. */
1750                 if (atomic_read(&ci->i_filelock_ref) > 0)
1751                         goto out;
1752         }
1753         /* The inode has cached pages, but it's no longer used.
1754          * we can safely drop it */
1755         if (wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1756             !(oissued & CEPH_CAP_FILE_CACHE)) {
1757           used = 0;
1758           oissued = 0;
1759         }
1760         if ((used | wanted) & ~oissued & mine)
1761                 goto out;   /* we need these caps */
1762
1763         if (oissued) {
1764                 /* we aren't the only cap.. just remove us */
1765                 __ceph_remove_cap(cap, true);
1766                 (*remaining)--;
1767         } else {
1768                 struct dentry *dentry;
1769                 /* try dropping referring dentries */
1770                 spin_unlock(&ci->i_ceph_lock);
1771                 dentry = d_find_any_alias(inode);
1772                 if (dentry && drop_negative_children(dentry)) {
1773                         int count;
1774                         dput(dentry);
1775                         d_prune_aliases(inode);
1776                         count = atomic_read(&inode->i_count);
1777                         if (count == 1)
1778                                 (*remaining)--;
1779                         dout("trim_caps_cb %p cap %p pruned, count now %d\n",
1780                              inode, cap, count);
1781                 } else {
1782                         dput(dentry);
1783                 }
1784                 return 0;
1785         }
1786
1787 out:
1788         spin_unlock(&ci->i_ceph_lock);
1789         return 0;
1790 }
1791
1792 /*
1793  * Trim session cap count down to some max number.
1794  */
1795 int ceph_trim_caps(struct ceph_mds_client *mdsc,
1796                    struct ceph_mds_session *session,
1797                    int max_caps)
1798 {
1799         int trim_caps = session->s_nr_caps - max_caps;
1800
1801         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1802              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1803         if (trim_caps > 0) {
1804                 int remaining = trim_caps;
1805
1806                 ceph_iterate_session_caps(session, trim_caps_cb, &remaining);
1807                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1808                      session->s_mds, session->s_nr_caps, max_caps,
1809                         trim_caps - remaining);
1810         }
1811
1812         ceph_flush_cap_releases(mdsc, session);
1813         return 0;
1814 }
1815
1816 static int check_caps_flush(struct ceph_mds_client *mdsc,
1817                             u64 want_flush_tid)
1818 {
1819         int ret = 1;
1820
1821         spin_lock(&mdsc->cap_dirty_lock);
1822         if (!list_empty(&mdsc->cap_flush_list)) {
1823                 struct ceph_cap_flush *cf =
1824                         list_first_entry(&mdsc->cap_flush_list,
1825                                          struct ceph_cap_flush, g_list);
1826                 if (cf->tid <= want_flush_tid) {
1827                         dout("check_caps_flush still flushing tid "
1828                              "%llu <= %llu\n", cf->tid, want_flush_tid);
1829                         ret = 0;
1830                 }
1831         }
1832         spin_unlock(&mdsc->cap_dirty_lock);
1833         return ret;
1834 }
1835
1836 /*
1837  * flush all dirty inode data to disk.
1838  *
1839  * returns true if we've flushed through want_flush_tid
1840  */
1841 static void wait_caps_flush(struct ceph_mds_client *mdsc,
1842                             u64 want_flush_tid)
1843 {
1844         dout("check_caps_flush want %llu\n", want_flush_tid);
1845
1846         wait_event(mdsc->cap_flushing_wq,
1847                    check_caps_flush(mdsc, want_flush_tid));
1848
1849         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
1850 }
1851
1852 /*
1853  * called under s_mutex
1854  */
1855 static void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1856                                    struct ceph_mds_session *session)
1857 {
1858         struct ceph_msg *msg = NULL;
1859         struct ceph_mds_cap_release *head;
1860         struct ceph_mds_cap_item *item;
1861         struct ceph_osd_client *osdc = &mdsc->fsc->client->osdc;
1862         struct ceph_cap *cap;
1863         LIST_HEAD(tmp_list);
1864         int num_cap_releases;
1865         __le32  barrier, *cap_barrier;
1866
1867         down_read(&osdc->lock);
1868         barrier = cpu_to_le32(osdc->epoch_barrier);
1869         up_read(&osdc->lock);
1870
1871         spin_lock(&session->s_cap_lock);
1872 again:
1873         list_splice_init(&session->s_cap_releases, &tmp_list);
1874         num_cap_releases = session->s_num_cap_releases;
1875         session->s_num_cap_releases = 0;
1876         spin_unlock(&session->s_cap_lock);
1877
1878         while (!list_empty(&tmp_list)) {
1879                 if (!msg) {
1880                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1881                                         PAGE_SIZE, GFP_NOFS, false);
1882                         if (!msg)
1883                                 goto out_err;
1884                         head = msg->front.iov_base;
1885                         head->num = cpu_to_le32(0);
1886                         msg->front.iov_len = sizeof(*head);
1887
1888                         msg->hdr.version = cpu_to_le16(2);
1889                         msg->hdr.compat_version = cpu_to_le16(1);
1890                 }
1891
1892                 cap = list_first_entry(&tmp_list, struct ceph_cap,
1893                                         session_caps);
1894                 list_del(&cap->session_caps);
1895                 num_cap_releases--;
1896
1897                 head = msg->front.iov_base;
1898                 put_unaligned_le32(get_unaligned_le32(&head->num) + 1,
1899                                    &head->num);
1900                 item = msg->front.iov_base + msg->front.iov_len;
1901                 item->ino = cpu_to_le64(cap->cap_ino);
1902                 item->cap_id = cpu_to_le64(cap->cap_id);
1903                 item->migrate_seq = cpu_to_le32(cap->mseq);
1904                 item->seq = cpu_to_le32(cap->issue_seq);
1905                 msg->front.iov_len += sizeof(*item);
1906
1907                 ceph_put_cap(mdsc, cap);
1908
1909                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1910                         // Append cap_barrier field
1911                         cap_barrier = msg->front.iov_base + msg->front.iov_len;
1912                         *cap_barrier = barrier;
1913                         msg->front.iov_len += sizeof(*cap_barrier);
1914
1915                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1916                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1917                         ceph_con_send(&session->s_con, msg);
1918                         msg = NULL;
1919                 }
1920         }
1921
1922         BUG_ON(num_cap_releases != 0);
1923
1924         spin_lock(&session->s_cap_lock);
1925         if (!list_empty(&session->s_cap_releases))
1926                 goto again;
1927         spin_unlock(&session->s_cap_lock);
1928
1929         if (msg) {
1930                 // Append cap_barrier field
1931                 cap_barrier = msg->front.iov_base + msg->front.iov_len;
1932                 *cap_barrier = barrier;
1933                 msg->front.iov_len += sizeof(*cap_barrier);
1934
1935                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1936                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1937                 ceph_con_send(&session->s_con, msg);
1938         }
1939         return;
1940 out_err:
1941         pr_err("send_cap_releases mds%d, failed to allocate message\n",
1942                 session->s_mds);
1943         spin_lock(&session->s_cap_lock);
1944         list_splice(&tmp_list, &session->s_cap_releases);
1945         session->s_num_cap_releases += num_cap_releases;
1946         spin_unlock(&session->s_cap_lock);
1947 }
1948
1949 static void ceph_cap_release_work(struct work_struct *work)
1950 {
1951         struct ceph_mds_session *session =
1952                 container_of(work, struct ceph_mds_session, s_cap_release_work);
1953
1954         mutex_lock(&session->s_mutex);
1955         if (session->s_state == CEPH_MDS_SESSION_OPEN ||
1956             session->s_state == CEPH_MDS_SESSION_HUNG)
1957                 ceph_send_cap_releases(session->s_mdsc, session);
1958         mutex_unlock(&session->s_mutex);
1959         ceph_put_mds_session(session);
1960 }
1961
1962 void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
1963                              struct ceph_mds_session *session)
1964 {
1965         if (mdsc->stopping)
1966                 return;
1967
1968         get_session(session);
1969         if (queue_work(mdsc->fsc->cap_wq,
1970                        &session->s_cap_release_work)) {
1971                 dout("cap release work queued\n");
1972         } else {
1973                 ceph_put_mds_session(session);
1974                 dout("failed to queue cap release work\n");
1975         }
1976 }
1977
1978 /*
1979  * caller holds session->s_cap_lock
1980  */
1981 void __ceph_queue_cap_release(struct ceph_mds_session *session,
1982                               struct ceph_cap *cap)
1983 {
1984         list_add_tail(&cap->session_caps, &session->s_cap_releases);
1985         session->s_num_cap_releases++;
1986
1987         if (!(session->s_num_cap_releases % CEPH_CAPS_PER_RELEASE))
1988                 ceph_flush_cap_releases(session->s_mdsc, session);
1989 }
1990
1991 static void ceph_cap_reclaim_work(struct work_struct *work)
1992 {
1993         struct ceph_mds_client *mdsc =
1994                 container_of(work, struct ceph_mds_client, cap_reclaim_work);
1995         int ret = ceph_trim_dentries(mdsc);
1996         if (ret == -EAGAIN)
1997                 ceph_queue_cap_reclaim_work(mdsc);
1998 }
1999
2000 void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc)
2001 {
2002         if (mdsc->stopping)
2003                 return;
2004
2005         if (queue_work(mdsc->fsc->cap_wq, &mdsc->cap_reclaim_work)) {
2006                 dout("caps reclaim work queued\n");
2007         } else {
2008                 dout("failed to queue caps release work\n");
2009         }
2010 }
2011
2012 void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr)
2013 {
2014         int val;
2015         if (!nr)
2016                 return;
2017         val = atomic_add_return(nr, &mdsc->cap_reclaim_pending);
2018         if (!(val % CEPH_CAPS_PER_RELEASE)) {
2019                 atomic_set(&mdsc->cap_reclaim_pending, 0);
2020                 ceph_queue_cap_reclaim_work(mdsc);
2021         }
2022 }
2023
2024 /*
2025  * requests
2026  */
2027
2028 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
2029                                     struct inode *dir)
2030 {
2031         struct ceph_inode_info *ci = ceph_inode(dir);
2032         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
2033         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
2034         size_t size = sizeof(struct ceph_mds_reply_dir_entry);
2035         int order, num_entries;
2036
2037         spin_lock(&ci->i_ceph_lock);
2038         num_entries = ci->i_files + ci->i_subdirs;
2039         spin_unlock(&ci->i_ceph_lock);
2040         num_entries = max(num_entries, 1);
2041         num_entries = min(num_entries, opt->max_readdir);
2042
2043         order = get_order(size * num_entries);
2044         while (order >= 0) {
2045                 rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
2046                                                              __GFP_NOWARN,
2047                                                              order);
2048                 if (rinfo->dir_entries)
2049                         break;
2050                 order--;
2051         }
2052         if (!rinfo->dir_entries)
2053                 return -ENOMEM;
2054
2055         num_entries = (PAGE_SIZE << order) / size;
2056         num_entries = min(num_entries, opt->max_readdir);
2057
2058         rinfo->dir_buf_size = PAGE_SIZE << order;
2059         req->r_num_caps = num_entries + 1;
2060         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
2061         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
2062         return 0;
2063 }
2064
2065 /*
2066  * Create an mds request.
2067  */
2068 struct ceph_mds_request *
2069 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
2070 {
2071         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
2072         struct timespec64 ts;
2073
2074         if (!req)
2075                 return ERR_PTR(-ENOMEM);
2076
2077         mutex_init(&req->r_fill_mutex);
2078         req->r_mdsc = mdsc;
2079         req->r_started = jiffies;
2080         req->r_resend_mds = -1;
2081         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
2082         INIT_LIST_HEAD(&req->r_unsafe_target_item);
2083         req->r_fmode = -1;
2084         kref_init(&req->r_kref);
2085         RB_CLEAR_NODE(&req->r_node);
2086         INIT_LIST_HEAD(&req->r_wait);
2087         init_completion(&req->r_completion);
2088         init_completion(&req->r_safe_completion);
2089         INIT_LIST_HEAD(&req->r_unsafe_item);
2090
2091         ktime_get_coarse_real_ts64(&ts);
2092         req->r_stamp = timespec64_trunc(ts, mdsc->fsc->sb->s_time_gran);
2093
2094         req->r_op = op;
2095         req->r_direct_mode = mode;
2096         return req;
2097 }
2098
2099 /*
2100  * return oldest (lowest) request, tid in request tree, 0 if none.
2101  *
2102  * called under mdsc->mutex.
2103  */
2104 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
2105 {
2106         if (RB_EMPTY_ROOT(&mdsc->request_tree))
2107                 return NULL;
2108         return rb_entry(rb_first(&mdsc->request_tree),
2109                         struct ceph_mds_request, r_node);
2110 }
2111
2112 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
2113 {
2114         return mdsc->oldest_tid;
2115 }
2116
2117 /*
2118  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
2119  * on build_path_from_dentry in fs/cifs/dir.c.
2120  *
2121  * If @stop_on_nosnap, generate path relative to the first non-snapped
2122  * inode.
2123  *
2124  * Encode hidden .snap dirs as a double /, i.e.
2125  *   foo/.snap/bar -> foo//bar
2126  */
2127 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
2128                            int stop_on_nosnap)
2129 {
2130         struct dentry *temp;
2131         char *path;
2132         int pos;
2133         unsigned seq;
2134         u64 base;
2135
2136         if (!dentry)
2137                 return ERR_PTR(-EINVAL);
2138
2139         path = __getname();
2140         if (!path)
2141                 return ERR_PTR(-ENOMEM);
2142 retry:
2143         pos = PATH_MAX - 1;
2144         path[pos] = '\0';
2145
2146         seq = read_seqbegin(&rename_lock);
2147         rcu_read_lock();
2148         temp = dentry;
2149         for (;;) {
2150                 struct inode *inode;
2151
2152                 spin_lock(&temp->d_lock);
2153                 inode = d_inode(temp);
2154                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
2155                         dout("build_path path+%d: %p SNAPDIR\n",
2156                              pos, temp);
2157                 } else if (stop_on_nosnap && inode && dentry != temp &&
2158                            ceph_snap(inode) == CEPH_NOSNAP) {
2159                         spin_unlock(&temp->d_lock);
2160                         pos++; /* get rid of any prepended '/' */
2161                         break;
2162                 } else {
2163                         pos -= temp->d_name.len;
2164                         if (pos < 0) {
2165                                 spin_unlock(&temp->d_lock);
2166                                 break;
2167                         }
2168                         memcpy(path + pos, temp->d_name.name, temp->d_name.len);
2169                 }
2170                 spin_unlock(&temp->d_lock);
2171                 temp = READ_ONCE(temp->d_parent);
2172
2173                 /* Are we at the root? */
2174                 if (IS_ROOT(temp))
2175                         break;
2176
2177                 /* Are we out of buffer? */
2178                 if (--pos < 0)
2179                         break;
2180
2181                 path[pos] = '/';
2182         }
2183         base = ceph_ino(d_inode(temp));
2184         rcu_read_unlock();
2185
2186         if (read_seqretry(&rename_lock, seq))
2187                 goto retry;
2188
2189         if (pos < 0) {
2190                 /*
2191                  * A rename didn't occur, but somehow we didn't end up where
2192                  * we thought we would. Throw a warning and try again.
2193                  */
2194                 pr_warn("build_path did not end path lookup where "
2195                         "expected, pos is %d\n", pos);
2196                 goto retry;
2197         }
2198
2199         *pbase = base;
2200         *plen = PATH_MAX - 1 - pos;
2201         dout("build_path on %p %d built %llx '%.*s'\n",
2202              dentry, d_count(dentry), base, *plen, path + pos);
2203         return path + pos;
2204 }
2205
2206 static int build_dentry_path(struct dentry *dentry, struct inode *dir,
2207                              const char **ppath, int *ppathlen, u64 *pino,
2208                              bool *pfreepath, bool parent_locked)
2209 {
2210         char *path;
2211
2212         rcu_read_lock();
2213         if (!dir)
2214                 dir = d_inode_rcu(dentry->d_parent);
2215         if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) {
2216                 *pino = ceph_ino(dir);
2217                 rcu_read_unlock();
2218                 *ppath = dentry->d_name.name;
2219                 *ppathlen = dentry->d_name.len;
2220                 return 0;
2221         }
2222         rcu_read_unlock();
2223         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2224         if (IS_ERR(path))
2225                 return PTR_ERR(path);
2226         *ppath = path;
2227         *pfreepath = true;
2228         return 0;
2229 }
2230
2231 static int build_inode_path(struct inode *inode,
2232                             const char **ppath, int *ppathlen, u64 *pino,
2233                             bool *pfreepath)
2234 {
2235         struct dentry *dentry;
2236         char *path;
2237
2238         if (ceph_snap(inode) == CEPH_NOSNAP) {
2239                 *pino = ceph_ino(inode);
2240                 *ppathlen = 0;
2241                 return 0;
2242         }
2243         dentry = d_find_alias(inode);
2244         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2245         dput(dentry);
2246         if (IS_ERR(path))
2247                 return PTR_ERR(path);
2248         *ppath = path;
2249         *pfreepath = true;
2250         return 0;
2251 }
2252
2253 /*
2254  * request arguments may be specified via an inode *, a dentry *, or
2255  * an explicit ino+path.
2256  */
2257 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
2258                                   struct inode *rdiri, const char *rpath,
2259                                   u64 rino, const char **ppath, int *pathlen,
2260                                   u64 *ino, bool *freepath, bool parent_locked)
2261 {
2262         int r = 0;
2263
2264         if (rinode) {
2265                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
2266                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
2267                      ceph_snap(rinode));
2268         } else if (rdentry) {
2269                 r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
2270                                         freepath, parent_locked);
2271                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
2272                      *ppath);
2273         } else if (rpath || rino) {
2274                 *ino = rino;
2275                 *ppath = rpath;
2276                 *pathlen = rpath ? strlen(rpath) : 0;
2277                 dout(" path %.*s\n", *pathlen, rpath);
2278         }
2279
2280         return r;
2281 }
2282
2283 /*
2284  * called under mdsc->mutex
2285  */
2286 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
2287                                                struct ceph_mds_request *req,
2288                                                int mds, bool drop_cap_releases)
2289 {
2290         struct ceph_msg *msg;
2291         struct ceph_mds_request_head *head;
2292         const char *path1 = NULL;
2293         const char *path2 = NULL;
2294         u64 ino1 = 0, ino2 = 0;
2295         int pathlen1 = 0, pathlen2 = 0;
2296         bool freepath1 = false, freepath2 = false;
2297         int len;
2298         u16 releases;
2299         void *p, *end;
2300         int ret;
2301
2302         ret = set_request_path_attr(req->r_inode, req->r_dentry,
2303                               req->r_parent, req->r_path1, req->r_ino1.ino,
2304                               &path1, &pathlen1, &ino1, &freepath1,
2305                               test_bit(CEPH_MDS_R_PARENT_LOCKED,
2306                                         &req->r_req_flags));
2307         if (ret < 0) {
2308                 msg = ERR_PTR(ret);
2309                 goto out;
2310         }
2311
2312         /* If r_old_dentry is set, then assume that its parent is locked */
2313         ret = set_request_path_attr(NULL, req->r_old_dentry,
2314                               req->r_old_dentry_dir,
2315                               req->r_path2, req->r_ino2.ino,
2316                               &path2, &pathlen2, &ino2, &freepath2, true);
2317         if (ret < 0) {
2318                 msg = ERR_PTR(ret);
2319                 goto out_free1;
2320         }
2321
2322         len = sizeof(*head) +
2323                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
2324                 sizeof(struct ceph_timespec);
2325
2326         /* calculate (max) length for cap releases */
2327         len += sizeof(struct ceph_mds_request_release) *
2328                 (!!req->r_inode_drop + !!req->r_dentry_drop +
2329                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
2330         if (req->r_dentry_drop)
2331                 len += pathlen1;
2332         if (req->r_old_dentry_drop)
2333                 len += pathlen2;
2334
2335         msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
2336         if (!msg) {
2337                 msg = ERR_PTR(-ENOMEM);
2338                 goto out_free2;
2339         }
2340
2341         msg->hdr.version = cpu_to_le16(2);
2342         msg->hdr.tid = cpu_to_le64(req->r_tid);
2343
2344         head = msg->front.iov_base;
2345         p = msg->front.iov_base + sizeof(*head);
2346         end = msg->front.iov_base + msg->front.iov_len;
2347
2348         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
2349         head->op = cpu_to_le32(req->r_op);
2350         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
2351         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
2352         head->ino = 0;
2353         head->args = req->r_args;
2354
2355         ceph_encode_filepath(&p, end, ino1, path1);
2356         ceph_encode_filepath(&p, end, ino2, path2);
2357
2358         /* make note of release offset, in case we need to replay */
2359         req->r_request_release_offset = p - msg->front.iov_base;
2360
2361         /* cap releases */
2362         releases = 0;
2363         if (req->r_inode_drop)
2364                 releases += ceph_encode_inode_release(&p,
2365                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
2366                       mds, req->r_inode_drop, req->r_inode_unless, 0);
2367         if (req->r_dentry_drop)
2368                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
2369                                 req->r_parent, mds, req->r_dentry_drop,
2370                                 req->r_dentry_unless);
2371         if (req->r_old_dentry_drop)
2372                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2373                                 req->r_old_dentry_dir, mds,
2374                                 req->r_old_dentry_drop,
2375                                 req->r_old_dentry_unless);
2376         if (req->r_old_inode_drop)
2377                 releases += ceph_encode_inode_release(&p,
2378                       d_inode(req->r_old_dentry),
2379                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2380
2381         if (drop_cap_releases) {
2382                 releases = 0;
2383                 p = msg->front.iov_base + req->r_request_release_offset;
2384         }
2385
2386         head->num_releases = cpu_to_le16(releases);
2387
2388         /* time stamp */
2389         {
2390                 struct ceph_timespec ts;
2391                 ceph_encode_timespec64(&ts, &req->r_stamp);
2392                 ceph_encode_copy(&p, &ts, sizeof(ts));
2393         }
2394
2395         BUG_ON(p > end);
2396         msg->front.iov_len = p - msg->front.iov_base;
2397         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2398
2399         if (req->r_pagelist) {
2400                 struct ceph_pagelist *pagelist = req->r_pagelist;
2401                 ceph_msg_data_add_pagelist(msg, pagelist);
2402                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2403         } else {
2404                 msg->hdr.data_len = 0;
2405         }
2406
2407         msg->hdr.data_off = cpu_to_le16(0);
2408
2409 out_free2:
2410         if (freepath2)
2411                 ceph_mdsc_free_path((char *)path2, pathlen2);
2412 out_free1:
2413         if (freepath1)
2414                 ceph_mdsc_free_path((char *)path1, pathlen1);
2415 out:
2416         return msg;
2417 }
2418
2419 /*
2420  * called under mdsc->mutex if error, under no mutex if
2421  * success.
2422  */
2423 static void complete_request(struct ceph_mds_client *mdsc,
2424                              struct ceph_mds_request *req)
2425 {
2426         if (req->r_callback)
2427                 req->r_callback(mdsc, req);
2428         complete_all(&req->r_completion);
2429 }
2430
2431 /*
2432  * called under mdsc->mutex
2433  */
2434 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2435                                   struct ceph_mds_request *req,
2436                                   int mds, bool drop_cap_releases)
2437 {
2438         struct ceph_mds_request_head *rhead;
2439         struct ceph_msg *msg;
2440         int flags = 0;
2441
2442         req->r_attempts++;
2443         if (req->r_inode) {
2444                 struct ceph_cap *cap =
2445                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2446
2447                 if (cap)
2448                         req->r_sent_on_mseq = cap->mseq;
2449                 else
2450                         req->r_sent_on_mseq = -1;
2451         }
2452         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2453              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2454
2455         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2456                 void *p;
2457                 /*
2458                  * Replay.  Do not regenerate message (and rebuild
2459                  * paths, etc.); just use the original message.
2460                  * Rebuilding paths will break for renames because
2461                  * d_move mangles the src name.
2462                  */
2463                 msg = req->r_request;
2464                 rhead = msg->front.iov_base;
2465
2466                 flags = le32_to_cpu(rhead->flags);
2467                 flags |= CEPH_MDS_FLAG_REPLAY;
2468                 rhead->flags = cpu_to_le32(flags);
2469
2470                 if (req->r_target_inode)
2471                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2472
2473                 rhead->num_retry = req->r_attempts - 1;
2474
2475                 /* remove cap/dentry releases from message */
2476                 rhead->num_releases = 0;
2477
2478                 /* time stamp */
2479                 p = msg->front.iov_base + req->r_request_release_offset;
2480                 {
2481                         struct ceph_timespec ts;
2482                         ceph_encode_timespec64(&ts, &req->r_stamp);
2483                         ceph_encode_copy(&p, &ts, sizeof(ts));
2484                 }
2485
2486                 msg->front.iov_len = p - msg->front.iov_base;
2487                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2488                 return 0;
2489         }
2490
2491         if (req->r_request) {
2492                 ceph_msg_put(req->r_request);
2493                 req->r_request = NULL;
2494         }
2495         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2496         if (IS_ERR(msg)) {
2497                 req->r_err = PTR_ERR(msg);
2498                 return PTR_ERR(msg);
2499         }
2500         req->r_request = msg;
2501
2502         rhead = msg->front.iov_base;
2503         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2504         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2505                 flags |= CEPH_MDS_FLAG_REPLAY;
2506         if (req->r_parent)
2507                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2508         rhead->flags = cpu_to_le32(flags);
2509         rhead->num_fwd = req->r_num_fwd;
2510         rhead->num_retry = req->r_attempts - 1;
2511         rhead->ino = 0;
2512
2513         dout(" r_parent = %p\n", req->r_parent);
2514         return 0;
2515 }
2516
2517 /*
2518  * send request, or put it on the appropriate wait list.
2519  */
2520 static void __do_request(struct ceph_mds_client *mdsc,
2521                         struct ceph_mds_request *req)
2522 {
2523         struct ceph_mds_session *session = NULL;
2524         int mds = -1;
2525         int err = 0;
2526
2527         if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2528                 if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2529                         __unregister_request(mdsc, req);
2530                 return;
2531         }
2532
2533         if (req->r_timeout &&
2534             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2535                 dout("do_request timed out\n");
2536                 err = -EIO;
2537                 goto finish;
2538         }
2539         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2540                 dout("do_request forced umount\n");
2541                 err = -EIO;
2542                 goto finish;
2543         }
2544         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2545                 if (mdsc->mdsmap_err) {
2546                         err = mdsc->mdsmap_err;
2547                         dout("do_request mdsmap err %d\n", err);
2548                         goto finish;
2549                 }
2550                 if (mdsc->mdsmap->m_epoch == 0) {
2551                         dout("do_request no mdsmap, waiting for map\n");
2552                         list_add(&req->r_wait, &mdsc->waiting_for_map);
2553                         return;
2554                 }
2555                 if (!(mdsc->fsc->mount_options->flags &
2556                       CEPH_MOUNT_OPT_MOUNTWAIT) &&
2557                     !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2558                         err = -ENOENT;
2559                         pr_info("probably no mds server is up\n");
2560                         goto finish;
2561                 }
2562         }
2563
2564         put_request_session(req);
2565
2566         mds = __choose_mds(mdsc, req);
2567         if (mds < 0 ||
2568             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2569                 dout("do_request no mds or not active, waiting for map\n");
2570                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2571                 return;
2572         }
2573
2574         /* get, open session */
2575         session = __ceph_lookup_mds_session(mdsc, mds);
2576         if (!session) {
2577                 session = register_session(mdsc, mds);
2578                 if (IS_ERR(session)) {
2579                         err = PTR_ERR(session);
2580                         goto finish;
2581                 }
2582         }
2583         req->r_session = get_session(session);
2584
2585         dout("do_request mds%d session %p state %s\n", mds, session,
2586              ceph_session_state_name(session->s_state));
2587         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2588             session->s_state != CEPH_MDS_SESSION_HUNG) {
2589                 if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2590                         err = -EACCES;
2591                         goto out_session;
2592                 }
2593                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2594                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2595                         __open_session(mdsc, session);
2596                 list_add(&req->r_wait, &session->s_waiting);
2597                 goto out_session;
2598         }
2599
2600         /* send request */
2601         req->r_resend_mds = -1;   /* forget any previous mds hint */
2602
2603         if (req->r_request_started == 0)   /* note request start time */
2604                 req->r_request_started = jiffies;
2605
2606         err = __prepare_send_request(mdsc, req, mds, false);
2607         if (!err) {
2608                 ceph_msg_get(req->r_request);
2609                 ceph_con_send(&session->s_con, req->r_request);
2610         }
2611
2612 out_session:
2613         ceph_put_mds_session(session);
2614 finish:
2615         if (err) {
2616                 dout("__do_request early error %d\n", err);
2617                 req->r_err = err;
2618                 complete_request(mdsc, req);
2619                 __unregister_request(mdsc, req);
2620         }
2621         return;
2622 }
2623
2624 /*
2625  * called under mdsc->mutex
2626  */
2627 static void __wake_requests(struct ceph_mds_client *mdsc,
2628                             struct list_head *head)
2629 {
2630         struct ceph_mds_request *req;
2631         LIST_HEAD(tmp_list);
2632
2633         list_splice_init(head, &tmp_list);
2634
2635         while (!list_empty(&tmp_list)) {
2636                 req = list_entry(tmp_list.next,
2637                                  struct ceph_mds_request, r_wait);
2638                 list_del_init(&req->r_wait);
2639                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2640                 __do_request(mdsc, req);
2641         }
2642 }
2643
2644 /*
2645  * Wake up threads with requests pending for @mds, so that they can
2646  * resubmit their requests to a possibly different mds.
2647  */
2648 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2649 {
2650         struct ceph_mds_request *req;
2651         struct rb_node *p = rb_first(&mdsc->request_tree);
2652
2653         dout("kick_requests mds%d\n", mds);
2654         while (p) {
2655                 req = rb_entry(p, struct ceph_mds_request, r_node);
2656                 p = rb_next(p);
2657                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2658                         continue;
2659                 if (req->r_attempts > 0)
2660                         continue; /* only new requests */
2661                 if (req->r_session &&
2662                     req->r_session->s_mds == mds) {
2663                         dout(" kicking tid %llu\n", req->r_tid);
2664                         list_del_init(&req->r_wait);
2665                         __do_request(mdsc, req);
2666                 }
2667         }
2668 }
2669
2670 int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
2671                               struct ceph_mds_request *req)
2672 {
2673         int err;
2674
2675         /* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
2676         if (req->r_inode)
2677                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2678         if (req->r_parent)
2679                 ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
2680         if (req->r_old_dentry_dir)
2681                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2682                                   CEPH_CAP_PIN);
2683
2684         dout("submit_request on %p for inode %p\n", req, dir);
2685         mutex_lock(&mdsc->mutex);
2686         __register_request(mdsc, req, dir);
2687         __do_request(mdsc, req);
2688         err = req->r_err;
2689         mutex_unlock(&mdsc->mutex);
2690         return err;
2691 }
2692
2693 static int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
2694                                   struct ceph_mds_request *req)
2695 {
2696         int err;
2697
2698         /* wait */
2699         dout("do_request waiting\n");
2700         if (!req->r_timeout && req->r_wait_for_completion) {
2701                 err = req->r_wait_for_completion(mdsc, req);
2702         } else {
2703                 long timeleft = wait_for_completion_killable_timeout(
2704                                         &req->r_completion,
2705                                         ceph_timeout_jiffies(req->r_timeout));
2706                 if (timeleft > 0)
2707                         err = 0;
2708                 else if (!timeleft)
2709                         err = -EIO;  /* timed out */
2710                 else
2711                         err = timeleft;  /* killed */
2712         }
2713         dout("do_request waited, got %d\n", err);
2714         mutex_lock(&mdsc->mutex);
2715
2716         /* only abort if we didn't race with a real reply */
2717         if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2718                 err = le32_to_cpu(req->r_reply_info.head->result);
2719         } else if (err < 0) {
2720                 dout("aborted request %lld with %d\n", req->r_tid, err);
2721
2722                 /*
2723                  * ensure we aren't running concurrently with
2724                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2725                  * rely on locks (dir mutex) held by our caller.
2726                  */
2727                 mutex_lock(&req->r_fill_mutex);
2728                 req->r_err = err;
2729                 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
2730                 mutex_unlock(&req->r_fill_mutex);
2731
2732                 if (req->r_parent &&
2733                     (req->r_op & CEPH_MDS_OP_WRITE))
2734                         ceph_invalidate_dir_request(req);
2735         } else {
2736                 err = req->r_err;
2737         }
2738
2739         mutex_unlock(&mdsc->mutex);
2740         return err;
2741 }
2742
2743 /*
2744  * Synchrously perform an mds request.  Take care of all of the
2745  * session setup, forwarding, retry details.
2746  */
2747 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2748                          struct inode *dir,
2749                          struct ceph_mds_request *req)
2750 {
2751         int err;
2752
2753         dout("do_request on %p\n", req);
2754
2755         /* issue */
2756         err = ceph_mdsc_submit_request(mdsc, dir, req);
2757         if (!err)
2758                 err = ceph_mdsc_wait_request(mdsc, req);
2759         dout("do_request %p done, result %d\n", req, err);
2760         return err;
2761 }
2762
2763 /*
2764  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2765  * namespace request.
2766  */
2767 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2768 {
2769         struct inode *dir = req->r_parent;
2770         struct inode *old_dir = req->r_old_dentry_dir;
2771
2772         dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
2773
2774         ceph_dir_clear_complete(dir);
2775         if (old_dir)
2776                 ceph_dir_clear_complete(old_dir);
2777         if (req->r_dentry)
2778                 ceph_invalidate_dentry_lease(req->r_dentry);
2779         if (req->r_old_dentry)
2780                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2781 }
2782
2783 /*
2784  * Handle mds reply.
2785  *
2786  * We take the session mutex and parse and process the reply immediately.
2787  * This preserves the logical ordering of replies, capabilities, etc., sent
2788  * by the MDS as they are applied to our local cache.
2789  */
2790 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2791 {
2792         struct ceph_mds_client *mdsc = session->s_mdsc;
2793         struct ceph_mds_request *req;
2794         struct ceph_mds_reply_head *head = msg->front.iov_base;
2795         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2796         struct ceph_snap_realm *realm;
2797         u64 tid;
2798         int err, result;
2799         int mds = session->s_mds;
2800
2801         if (msg->front.iov_len < sizeof(*head)) {
2802                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2803                 ceph_msg_dump(msg);
2804                 return;
2805         }
2806
2807         /* get request, session */
2808         tid = le64_to_cpu(msg->hdr.tid);
2809         mutex_lock(&mdsc->mutex);
2810         req = lookup_get_request(mdsc, tid);
2811         if (!req) {
2812                 dout("handle_reply on unknown tid %llu\n", tid);
2813                 mutex_unlock(&mdsc->mutex);
2814                 return;
2815         }
2816         dout("handle_reply %p\n", req);
2817
2818         /* correct session? */
2819         if (req->r_session != session) {
2820                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2821                        " not mds%d\n", tid, session->s_mds,
2822                        req->r_session ? req->r_session->s_mds : -1);
2823                 mutex_unlock(&mdsc->mutex);
2824                 goto out;
2825         }
2826
2827         /* dup? */
2828         if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
2829             (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
2830                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2831                            head->safe ? "safe" : "unsafe", tid, mds);
2832                 mutex_unlock(&mdsc->mutex);
2833                 goto out;
2834         }
2835         if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
2836                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2837                            tid, mds);
2838                 mutex_unlock(&mdsc->mutex);
2839                 goto out;
2840         }
2841
2842         result = le32_to_cpu(head->result);
2843
2844         /*
2845          * Handle an ESTALE
2846          * if we're not talking to the authority, send to them
2847          * if the authority has changed while we weren't looking,
2848          * send to new authority
2849          * Otherwise we just have to return an ESTALE
2850          */
2851         if (result == -ESTALE) {
2852                 dout("got ESTALE on request %llu\n", req->r_tid);
2853                 req->r_resend_mds = -1;
2854                 if (req->r_direct_mode != USE_AUTH_MDS) {
2855                         dout("not using auth, setting for that now\n");
2856                         req->r_direct_mode = USE_AUTH_MDS;
2857                         __do_request(mdsc, req);
2858                         mutex_unlock(&mdsc->mutex);
2859                         goto out;
2860                 } else  {
2861                         int mds = __choose_mds(mdsc, req);
2862                         if (mds >= 0 && mds != req->r_session->s_mds) {
2863                                 dout("but auth changed, so resending\n");
2864                                 __do_request(mdsc, req);
2865                                 mutex_unlock(&mdsc->mutex);
2866                                 goto out;
2867                         }
2868                 }
2869                 dout("have to return ESTALE on request %llu\n", req->r_tid);
2870         }
2871
2872
2873         if (head->safe) {
2874                 set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
2875                 __unregister_request(mdsc, req);
2876
2877                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2878                         /*
2879                          * We already handled the unsafe response, now do the
2880                          * cleanup.  No need to examine the response; the MDS
2881                          * doesn't include any result info in the safe
2882                          * response.  And even if it did, there is nothing
2883                          * useful we could do with a revised return value.
2884                          */
2885                         dout("got safe reply %llu, mds%d\n", tid, mds);
2886
2887                         /* last unsafe request during umount? */
2888                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2889                                 complete_all(&mdsc->safe_umount_waiters);
2890                         mutex_unlock(&mdsc->mutex);
2891                         goto out;
2892                 }
2893         } else {
2894                 set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
2895                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2896                 if (req->r_unsafe_dir) {
2897                         struct ceph_inode_info *ci =
2898                                         ceph_inode(req->r_unsafe_dir);
2899                         spin_lock(&ci->i_unsafe_lock);
2900                         list_add_tail(&req->r_unsafe_dir_item,
2901                                       &ci->i_unsafe_dirops);
2902                         spin_unlock(&ci->i_unsafe_lock);
2903                 }
2904         }
2905
2906         dout("handle_reply tid %lld result %d\n", tid, result);
2907         rinfo = &req->r_reply_info;
2908         if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
2909                 err = parse_reply_info(msg, rinfo, (u64)-1);
2910         else
2911                 err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2912         mutex_unlock(&mdsc->mutex);
2913
2914         mutex_lock(&session->s_mutex);
2915         if (err < 0) {
2916                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2917                 ceph_msg_dump(msg);
2918                 goto out_err;
2919         }
2920
2921         /* snap trace */
2922         realm = NULL;
2923         if (rinfo->snapblob_len) {
2924                 down_write(&mdsc->snap_rwsem);
2925                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2926                                 rinfo->snapblob + rinfo->snapblob_len,
2927                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2928                                 &realm);
2929                 downgrade_write(&mdsc->snap_rwsem);
2930         } else {
2931                 down_read(&mdsc->snap_rwsem);
2932         }
2933
2934         /* insert trace into our cache */
2935         mutex_lock(&req->r_fill_mutex);
2936         current->journal_info = req;
2937         err = ceph_fill_trace(mdsc->fsc->sb, req);
2938         if (err == 0) {
2939                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2940                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2941                         ceph_readdir_prepopulate(req, req->r_session);
2942         }
2943         current->journal_info = NULL;
2944         mutex_unlock(&req->r_fill_mutex);
2945
2946         up_read(&mdsc->snap_rwsem);
2947         if (realm)
2948                 ceph_put_snap_realm(mdsc, realm);
2949
2950         if (err == 0) {
2951                 if (req->r_target_inode &&
2952                     test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2953                         struct ceph_inode_info *ci =
2954                                 ceph_inode(req->r_target_inode);
2955                         spin_lock(&ci->i_unsafe_lock);
2956                         list_add_tail(&req->r_unsafe_target_item,
2957                                       &ci->i_unsafe_iops);
2958                         spin_unlock(&ci->i_unsafe_lock);
2959                 }
2960
2961                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2962         }
2963 out_err:
2964         mutex_lock(&mdsc->mutex);
2965         if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
2966                 if (err) {
2967                         req->r_err = err;
2968                 } else {
2969                         req->r_reply =  ceph_msg_get(msg);
2970                         set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
2971                 }
2972         } else {
2973                 dout("reply arrived after request %lld was aborted\n", tid);
2974         }
2975         mutex_unlock(&mdsc->mutex);
2976
2977         mutex_unlock(&session->s_mutex);
2978
2979         /* kick calling process */
2980         complete_request(mdsc, req);
2981 out:
2982         ceph_mdsc_put_request(req);
2983         return;
2984 }
2985
2986
2987
2988 /*
2989  * handle mds notification that our request has been forwarded.
2990  */
2991 static void handle_forward(struct ceph_mds_client *mdsc,
2992                            struct ceph_mds_session *session,
2993                            struct ceph_msg *msg)
2994 {
2995         struct ceph_mds_request *req;
2996         u64 tid = le64_to_cpu(msg->hdr.tid);
2997         u32 next_mds;
2998         u32 fwd_seq;
2999         int err = -EINVAL;
3000         void *p = msg->front.iov_base;
3001         void *end = p + msg->front.iov_len;
3002
3003         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
3004         next_mds = ceph_decode_32(&p);
3005         fwd_seq = ceph_decode_32(&p);
3006
3007         mutex_lock(&mdsc->mutex);
3008         req = lookup_get_request(mdsc, tid);
3009         if (!req) {
3010                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
3011                 goto out;  /* dup reply? */
3012         }
3013
3014         if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3015                 dout("forward tid %llu aborted, unregistering\n", tid);
3016                 __unregister_request(mdsc, req);
3017         } else if (fwd_seq <= req->r_num_fwd) {
3018                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
3019                      tid, next_mds, req->r_num_fwd, fwd_seq);
3020         } else {
3021                 /* resend. forward race not possible; mds would drop */
3022                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
3023                 BUG_ON(req->r_err);
3024                 BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
3025                 req->r_attempts = 0;
3026                 req->r_num_fwd = fwd_seq;
3027                 req->r_resend_mds = next_mds;
3028                 put_request_session(req);
3029                 __do_request(mdsc, req);
3030         }
3031         ceph_mdsc_put_request(req);
3032 out:
3033         mutex_unlock(&mdsc->mutex);
3034         return;
3035
3036 bad:
3037         pr_err("mdsc_handle_forward decode error err=%d\n", err);
3038 }
3039
3040 static int __decode_session_metadata(void **p, void *end,
3041                                      bool *blacklisted)
3042 {
3043         /* map<string,string> */
3044         u32 n;
3045         bool err_str;
3046         ceph_decode_32_safe(p, end, n, bad);
3047         while (n-- > 0) {
3048                 u32 len;
3049                 ceph_decode_32_safe(p, end, len, bad);
3050                 ceph_decode_need(p, end, len, bad);
3051                 err_str = !strncmp(*p, "error_string", len);
3052                 *p += len;
3053                 ceph_decode_32_safe(p, end, len, bad);
3054                 ceph_decode_need(p, end, len, bad);
3055                 if (err_str && strnstr(*p, "blacklisted", len))
3056                         *blacklisted = true;
3057                 *p += len;
3058         }
3059         return 0;
3060 bad:
3061         return -1;
3062 }
3063
3064 /*
3065  * handle a mds session control message
3066  */
3067 static void handle_session(struct ceph_mds_session *session,
3068                            struct ceph_msg *msg)
3069 {
3070         struct ceph_mds_client *mdsc = session->s_mdsc;
3071         int mds = session->s_mds;
3072         int msg_version = le16_to_cpu(msg->hdr.version);
3073         void *p = msg->front.iov_base;
3074         void *end = p + msg->front.iov_len;
3075         struct ceph_mds_session_head *h;
3076         u32 op;
3077         u64 seq;
3078         unsigned long features = 0;
3079         int wake = 0;
3080         bool blacklisted = false;
3081
3082         /* decode */
3083         ceph_decode_need(&p, end, sizeof(*h), bad);
3084         h = p;
3085         p += sizeof(*h);
3086
3087         op = le32_to_cpu(h->op);
3088         seq = le64_to_cpu(h->seq);
3089
3090         if (msg_version >= 3) {
3091                 u32 len;
3092                 /* version >= 2, metadata */
3093                 if (__decode_session_metadata(&p, end, &blacklisted) < 0)
3094                         goto bad;
3095                 /* version >= 3, feature bits */
3096                 ceph_decode_32_safe(&p, end, len, bad);
3097                 ceph_decode_need(&p, end, len, bad);
3098                 memcpy(&features, p, min_t(size_t, len, sizeof(features)));
3099                 p += len;
3100         }
3101
3102         mutex_lock(&mdsc->mutex);
3103         if (op == CEPH_SESSION_CLOSE) {
3104                 get_session(session);
3105                 __unregister_session(mdsc, session);
3106         }
3107         /* FIXME: this ttl calculation is generous */
3108         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
3109         mutex_unlock(&mdsc->mutex);
3110
3111         mutex_lock(&session->s_mutex);
3112
3113         dout("handle_session mds%d %s %p state %s seq %llu\n",
3114              mds, ceph_session_op_name(op), session,
3115              ceph_session_state_name(session->s_state), seq);
3116
3117         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
3118                 session->s_state = CEPH_MDS_SESSION_OPEN;
3119                 pr_info("mds%d came back\n", session->s_mds);
3120         }
3121
3122         switch (op) {
3123         case CEPH_SESSION_OPEN:
3124                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3125                         pr_info("mds%d reconnect success\n", session->s_mds);
3126                 session->s_state = CEPH_MDS_SESSION_OPEN;
3127                 session->s_features = features;
3128                 renewed_caps(mdsc, session, 0);
3129                 wake = 1;
3130                 if (mdsc->stopping)
3131                         __close_session(mdsc, session);
3132                 break;
3133
3134         case CEPH_SESSION_RENEWCAPS:
3135                 if (session->s_renew_seq == seq)
3136                         renewed_caps(mdsc, session, 1);
3137                 break;
3138
3139         case CEPH_SESSION_CLOSE:
3140                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3141                         pr_info("mds%d reconnect denied\n", session->s_mds);
3142                 cleanup_session_requests(mdsc, session);
3143                 remove_session_caps(session);
3144                 wake = 2; /* for good measure */
3145                 wake_up_all(&mdsc->session_close_wq);
3146                 break;
3147
3148         case CEPH_SESSION_STALE:
3149                 pr_info("mds%d caps went stale, renewing\n",
3150                         session->s_mds);
3151                 spin_lock(&session->s_gen_ttl_lock);
3152                 session->s_cap_gen++;
3153                 session->s_cap_ttl = jiffies - 1;
3154                 spin_unlock(&session->s_gen_ttl_lock);
3155                 send_renew_caps(mdsc, session);
3156                 break;
3157
3158         case CEPH_SESSION_RECALL_STATE:
3159                 ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
3160                 break;
3161
3162         case CEPH_SESSION_FLUSHMSG:
3163                 send_flushmsg_ack(mdsc, session, seq);
3164                 break;
3165
3166         case CEPH_SESSION_FORCE_RO:
3167                 dout("force_session_readonly %p\n", session);
3168                 spin_lock(&session->s_cap_lock);
3169                 session->s_readonly = true;
3170                 spin_unlock(&session->s_cap_lock);
3171                 wake_up_session_caps(session, FORCE_RO);
3172                 break;
3173
3174         case CEPH_SESSION_REJECT:
3175                 WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
3176                 pr_info("mds%d rejected session\n", session->s_mds);
3177                 session->s_state = CEPH_MDS_SESSION_REJECTED;
3178                 cleanup_session_requests(mdsc, session);
3179                 remove_session_caps(session);
3180                 if (blacklisted)
3181                         mdsc->fsc->blacklisted = true;
3182                 wake = 2; /* for good measure */
3183                 break;
3184
3185         default:
3186                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
3187                 WARN_ON(1);
3188         }
3189
3190         mutex_unlock(&session->s_mutex);
3191         if (wake) {
3192                 mutex_lock(&mdsc->mutex);
3193                 __wake_requests(mdsc, &session->s_waiting);
3194                 if (wake == 2)
3195                         kick_requests(mdsc, mds);
3196                 mutex_unlock(&mdsc->mutex);
3197         }
3198         if (op == CEPH_SESSION_CLOSE)
3199                 ceph_put_mds_session(session);
3200         return;
3201
3202 bad:
3203         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
3204                (int)msg->front.iov_len);
3205         ceph_msg_dump(msg);
3206         return;
3207 }
3208
3209
3210 /*
3211  * called under session->mutex.
3212  */
3213 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
3214                                    struct ceph_mds_session *session)
3215 {
3216         struct ceph_mds_request *req, *nreq;
3217         struct rb_node *p;
3218         int err;
3219
3220         dout("replay_unsafe_requests mds%d\n", session->s_mds);
3221
3222         mutex_lock(&mdsc->mutex);
3223         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
3224                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
3225                 if (!err) {
3226                         ceph_msg_get(req->r_request);
3227                         ceph_con_send(&session->s_con, req->r_request);
3228                 }
3229         }
3230
3231         /*
3232          * also re-send old requests when MDS enters reconnect stage. So that MDS
3233          * can process completed request in clientreplay stage.
3234          */
3235         p = rb_first(&mdsc->request_tree);
3236         while (p) {
3237                 req = rb_entry(p, struct ceph_mds_request, r_node);
3238                 p = rb_next(p);
3239                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3240                         continue;
3241                 if (req->r_attempts == 0)
3242                         continue; /* only old requests */
3243                 if (req->r_session &&
3244                     req->r_session->s_mds == session->s_mds) {
3245                         err = __prepare_send_request(mdsc, req,
3246                                                      session->s_mds, true);
3247                         if (!err) {
3248                                 ceph_msg_get(req->r_request);
3249                                 ceph_con_send(&session->s_con, req->r_request);
3250                         }
3251                 }
3252         }
3253         mutex_unlock(&mdsc->mutex);
3254 }
3255
3256 static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
3257 {
3258         struct ceph_msg *reply;
3259         struct ceph_pagelist *_pagelist;
3260         struct page *page;
3261         __le32 *addr;
3262         int err = -ENOMEM;
3263
3264         if (!recon_state->allow_multi)
3265                 return -ENOSPC;
3266
3267         /* can't handle message that contains both caps and realm */
3268         BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3269
3270         /* pre-allocate new pagelist */
3271         _pagelist = ceph_pagelist_alloc(GFP_NOFS);
3272         if (!_pagelist)
3273                 return -ENOMEM;
3274
3275         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3276         if (!reply)
3277                 goto fail_msg;
3278
3279         /* placeholder for nr_caps */
3280         err = ceph_pagelist_encode_32(_pagelist, 0);
3281         if (err < 0)
3282                 goto fail;
3283
3284         if (recon_state->nr_caps) {
3285                 /* currently encoding caps */
3286                 err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3287                 if (err)
3288                         goto fail;
3289         } else {
3290                 /* placeholder for nr_realms (currently encoding relams) */
3291                 err = ceph_pagelist_encode_32(_pagelist, 0);
3292                 if (err < 0)
3293                         goto fail;
3294         }
3295
3296         err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3297         if (err)
3298                 goto fail;
3299
3300         page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3301         addr = kmap_atomic(page);
3302         if (recon_state->nr_caps) {
3303                 /* currently encoding caps */
3304                 *addr = cpu_to_le32(recon_state->nr_caps);
3305         } else {
3306                 /* currently encoding relams */
3307                 *(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3308         }
3309         kunmap_atomic(addr);
3310
3311         reply->hdr.version = cpu_to_le16(5);
3312         reply->hdr.compat_version = cpu_to_le16(4);
3313
3314         reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3315         ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3316
3317         ceph_con_send(&recon_state->session->s_con, reply);
3318         ceph_pagelist_release(recon_state->pagelist);
3319
3320         recon_state->pagelist = _pagelist;
3321         recon_state->nr_caps = 0;
3322         recon_state->nr_realms = 0;
3323         recon_state->msg_version = 5;
3324         return 0;
3325 fail:
3326         ceph_msg_put(reply);
3327 fail_msg:
3328         ceph_pagelist_release(_pagelist);
3329         return err;
3330 }
3331
3332 /*
3333  * Encode information about a cap for a reconnect with the MDS.
3334  */
3335 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
3336                           void *arg)
3337 {
3338         union {
3339                 struct ceph_mds_cap_reconnect v2;
3340                 struct ceph_mds_cap_reconnect_v1 v1;
3341         } rec;
3342         struct ceph_inode_info *ci = cap->ci;
3343         struct ceph_reconnect_state *recon_state = arg;
3344         struct ceph_pagelist *pagelist = recon_state->pagelist;
3345         int err;
3346         u64 snap_follows;
3347
3348         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3349              inode, ceph_vinop(inode), cap, cap->cap_id,
3350              ceph_cap_string(cap->issued));
3351
3352         spin_lock(&ci->i_ceph_lock);
3353         cap->seq = 0;        /* reset cap seq */
3354         cap->issue_seq = 0;  /* and issue_seq */
3355         cap->mseq = 0;       /* and migrate_seq */
3356         cap->cap_gen = cap->session->s_cap_gen;
3357
3358         if (recon_state->msg_version >= 2) {
3359                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3360                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3361                 rec.v2.issued = cpu_to_le32(cap->issued);
3362                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3363                 rec.v2.pathbase = 0;
3364                 rec.v2.flock_len = (__force __le32)
3365                         ((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3366         } else {
3367                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3368                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3369                 rec.v1.issued = cpu_to_le32(cap->issued);
3370                 rec.v1.size = cpu_to_le64(inode->i_size);
3371                 ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3372                 ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3373                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3374                 rec.v1.pathbase = 0;
3375         }
3376
3377         if (list_empty(&ci->i_cap_snaps)) {
3378                 snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3379         } else {
3380                 struct ceph_cap_snap *capsnap =
3381                         list_first_entry(&ci->i_cap_snaps,
3382                                          struct ceph_cap_snap, ci_item);
3383                 snap_follows = capsnap->follows;
3384         }
3385         spin_unlock(&ci->i_ceph_lock);
3386
3387         if (recon_state->msg_version >= 2) {
3388                 int num_fcntl_locks, num_flock_locks;
3389                 struct ceph_filelock *flocks = NULL;
3390                 size_t struct_len, total_len = sizeof(u64);
3391                 u8 struct_v = 0;
3392
3393 encode_again:
3394                 if (rec.v2.flock_len) {
3395                         ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
3396                 } else {
3397                         num_fcntl_locks = 0;
3398                         num_flock_locks = 0;
3399                 }
3400                 if (num_fcntl_locks + num_flock_locks > 0) {
3401                         flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
3402                                                sizeof(struct ceph_filelock),
3403                                                GFP_NOFS);
3404                         if (!flocks) {
3405                                 err = -ENOMEM;
3406                                 goto out_err;
3407                         }
3408                         err = ceph_encode_locks_to_buffer(inode, flocks,
3409                                                           num_fcntl_locks,
3410                                                           num_flock_locks);
3411                         if (err) {
3412                                 kfree(flocks);
3413                                 flocks = NULL;
3414                                 if (err == -ENOSPC)
3415                                         goto encode_again;
3416                                 goto out_err;
3417                         }
3418                 } else {
3419                         kfree(flocks);
3420                         flocks = NULL;
3421                 }
3422
3423                 if (recon_state->msg_version >= 3) {
3424                         /* version, compat_version and struct_len */
3425                         total_len += 2 * sizeof(u8) + sizeof(u32);
3426                         struct_v = 2;
3427                 }
3428                 /*
3429                  * number of encoded locks is stable, so copy to pagelist
3430                  */
3431                 struct_len = 2 * sizeof(u32) +
3432                             (num_fcntl_locks + num_flock_locks) *
3433                             sizeof(struct ceph_filelock);
3434                 rec.v2.flock_len = cpu_to_le32(struct_len);
3435
3436                 struct_len += sizeof(u32) + sizeof(rec.v2);
3437
3438                 if (struct_v >= 2)
3439                         struct_len += sizeof(u64); /* snap_follows */
3440
3441                 total_len += struct_len;
3442
3443                 if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
3444                         err = send_reconnect_partial(recon_state);
3445                         if (err)
3446                                 goto out_freeflocks;
3447                         pagelist = recon_state->pagelist;
3448                 }
3449
3450                 err = ceph_pagelist_reserve(pagelist, total_len);
3451                 if (err)
3452                         goto out_freeflocks;
3453
3454                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3455                 if (recon_state->msg_version >= 3) {
3456                         ceph_pagelist_encode_8(pagelist, struct_v);
3457                         ceph_pagelist_encode_8(pagelist, 1);
3458                         ceph_pagelist_encode_32(pagelist, struct_len);
3459                 }
3460                 ceph_pagelist_encode_string(pagelist, NULL, 0);
3461                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
3462                 ceph_locks_to_pagelist(flocks, pagelist,
3463                                        num_fcntl_locks, num_flock_locks);
3464                 if (struct_v >= 2)
3465                         ceph_pagelist_encode_64(pagelist, snap_follows);
3466 out_freeflocks:
3467                 kfree(flocks);
3468         } else {
3469                 u64 pathbase = 0;
3470                 int pathlen = 0;
3471                 char *path = NULL;
3472                 struct dentry *dentry;
3473
3474                 dentry = d_find_alias(inode);
3475                 if (dentry) {
3476                         path = ceph_mdsc_build_path(dentry,
3477                                                 &pathlen, &pathbase, 0);
3478                         dput(dentry);
3479                         if (IS_ERR(path)) {
3480                                 err = PTR_ERR(path);
3481                                 goto out_err;
3482                         }
3483                         rec.v1.pathbase = cpu_to_le64(pathbase);
3484                 }
3485
3486                 err = ceph_pagelist_reserve(pagelist,
3487                                             sizeof(u64) + sizeof(u32) +
3488                                             pathlen + sizeof(rec.v1));
3489                 if (err) {
3490                         goto out_freepath;
3491                 }
3492
3493                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3494                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3495                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
3496 out_freepath:
3497                 ceph_mdsc_free_path(path, pathlen);
3498         }
3499
3500 out_err:
3501         if (err >= 0)
3502                 recon_state->nr_caps++;
3503         return err;
3504 }
3505
3506 static int encode_snap_realms(struct ceph_mds_client *mdsc,
3507                               struct ceph_reconnect_state *recon_state)
3508 {
3509         struct rb_node *p;
3510         struct ceph_pagelist *pagelist = recon_state->pagelist;
3511         int err = 0;
3512
3513         if (recon_state->msg_version >= 4) {
3514                 err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
3515                 if (err < 0)
3516                         goto fail;
3517         }
3518
3519         /*
3520          * snaprealms.  we provide mds with the ino, seq (version), and
3521          * parent for all of our realms.  If the mds has any newer info,
3522          * it will tell us.
3523          */
3524         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3525                 struct ceph_snap_realm *realm =
3526                        rb_entry(p, struct ceph_snap_realm, node);
3527                 struct ceph_mds_snaprealm_reconnect sr_rec;
3528
3529                 if (recon_state->msg_version >= 4) {
3530                         size_t need = sizeof(u8) * 2 + sizeof(u32) +
3531                                       sizeof(sr_rec);
3532
3533                         if (pagelist->length + need > RECONNECT_MAX_SIZE) {
3534                                 err = send_reconnect_partial(recon_state);
3535                                 if (err)
3536                                         goto fail;
3537                                 pagelist = recon_state->pagelist;
3538                         }
3539
3540                         err = ceph_pagelist_reserve(pagelist, need);
3541                         if (err)
3542                                 goto fail;
3543
3544                         ceph_pagelist_encode_8(pagelist, 1);
3545                         ceph_pagelist_encode_8(pagelist, 1);
3546                         ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
3547                 }
3548
3549                 dout(" adding snap realm %llx seq %lld parent %llx\n",
3550                      realm->ino, realm->seq, realm->parent_ino);
3551                 sr_rec.ino = cpu_to_le64(realm->ino);
3552                 sr_rec.seq = cpu_to_le64(realm->seq);
3553                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
3554
3555                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3556                 if (err)
3557                         goto fail;
3558
3559                 recon_state->nr_realms++;
3560         }
3561 fail:
3562         return err;
3563 }
3564
3565
3566 /*
3567  * If an MDS fails and recovers, clients need to reconnect in order to
3568  * reestablish shared state.  This includes all caps issued through
3569  * this session _and_ the snap_realm hierarchy.  Because it's not
3570  * clear which snap realms the mds cares about, we send everything we
3571  * know about.. that ensures we'll then get any new info the
3572  * recovering MDS might have.
3573  *
3574  * This is a relatively heavyweight operation, but it's rare.
3575  *
3576  * called with mdsc->mutex held.
3577  */
3578 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
3579                                struct ceph_mds_session *session)
3580 {
3581         struct ceph_msg *reply;
3582         int mds = session->s_mds;
3583         int err = -ENOMEM;
3584         struct ceph_reconnect_state recon_state = {
3585                 .session = session,
3586         };
3587         LIST_HEAD(dispose);
3588
3589         pr_info("mds%d reconnect start\n", mds);
3590
3591         recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
3592         if (!recon_state.pagelist)
3593                 goto fail_nopagelist;
3594
3595         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3596         if (!reply)
3597                 goto fail_nomsg;
3598
3599         mutex_lock(&session->s_mutex);
3600         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
3601         session->s_seq = 0;
3602
3603         dout("session %p state %s\n", session,
3604              ceph_session_state_name(session->s_state));
3605
3606         spin_lock(&session->s_gen_ttl_lock);
3607         session->s_cap_gen++;
3608         spin_unlock(&session->s_gen_ttl_lock);
3609
3610         spin_lock(&session->s_cap_lock);
3611         /* don't know if session is readonly */
3612         session->s_readonly = 0;
3613         /*
3614          * notify __ceph_remove_cap() that we are composing cap reconnect.
3615          * If a cap get released before being added to the cap reconnect,
3616          * __ceph_remove_cap() should skip queuing cap release.
3617          */
3618         session->s_cap_reconnect = 1;
3619         /* drop old cap expires; we're about to reestablish that state */
3620         detach_cap_releases(session, &dispose);
3621         spin_unlock(&session->s_cap_lock);
3622         dispose_cap_releases(mdsc, &dispose);
3623
3624         /* trim unused caps to reduce MDS's cache rejoin time */
3625         if (mdsc->fsc->sb->s_root)
3626                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
3627
3628         ceph_con_close(&session->s_con);
3629         ceph_con_open(&session->s_con,
3630                       CEPH_ENTITY_TYPE_MDS, mds,
3631                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
3632
3633         /* replay unsafe requests */
3634         replay_unsafe_requests(mdsc, session);
3635
3636         ceph_early_kick_flushing_caps(mdsc, session);
3637
3638         down_read(&mdsc->snap_rwsem);
3639
3640         /* placeholder for nr_caps */
3641         err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
3642         if (err)
3643                 goto fail;
3644
3645         if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
3646                 recon_state.msg_version = 3;
3647                 recon_state.allow_multi = true;
3648         } else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
3649                 recon_state.msg_version = 3;
3650         } else {
3651                 recon_state.msg_version = 2;
3652         }
3653         /* trsaverse this session's caps */
3654         err = ceph_iterate_session_caps(session, encode_caps_cb, &recon_state);
3655
3656         spin_lock(&session->s_cap_lock);
3657         session->s_cap_reconnect = 0;
3658         spin_unlock(&session->s_cap_lock);
3659
3660         if (err < 0)
3661                 goto fail;
3662
3663         /* check if all realms can be encoded into current message */
3664         if (mdsc->num_snap_realms) {
3665                 size_t total_len =
3666                         recon_state.pagelist->length +
3667                         mdsc->num_snap_realms *
3668                         sizeof(struct ceph_mds_snaprealm_reconnect);
3669                 if (recon_state.msg_version >= 4) {
3670                         /* number of realms */
3671                         total_len += sizeof(u32);
3672                         /* version, compat_version and struct_len */
3673                         total_len += mdsc->num_snap_realms *
3674                                      (2 * sizeof(u8) + sizeof(u32));
3675                 }
3676                 if (total_len > RECONNECT_MAX_SIZE) {
3677                         if (!recon_state.allow_multi) {
3678                                 err = -ENOSPC;
3679                                 goto fail;
3680                         }
3681                         if (recon_state.nr_caps) {
3682                                 err = send_reconnect_partial(&recon_state);
3683                                 if (err)
3684                                         goto fail;
3685                         }
3686                         recon_state.msg_version = 5;
3687                 }
3688         }
3689
3690         err = encode_snap_realms(mdsc, &recon_state);
3691         if (err < 0)
3692                 goto fail;
3693
3694         if (recon_state.msg_version >= 5) {
3695                 err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
3696                 if (err < 0)
3697                         goto fail;
3698         }
3699
3700         if (recon_state.nr_caps || recon_state.nr_realms) {
3701                 struct page *page =
3702                         list_first_entry(&recon_state.pagelist->head,
3703                                         struct page, lru);
3704                 __le32 *addr = kmap_atomic(page);
3705                 if (recon_state.nr_caps) {
3706                         WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
3707                         *addr = cpu_to_le32(recon_state.nr_caps);
3708                 } else if (recon_state.msg_version >= 4) {
3709                         *(addr + 1) = cpu_to_le32(recon_state.nr_realms);
3710                 }
3711                 kunmap_atomic(addr);
3712         }
3713
3714         reply->hdr.version = cpu_to_le16(recon_state.msg_version);
3715         if (recon_state.msg_version >= 4)
3716                 reply->hdr.compat_version = cpu_to_le16(4);
3717
3718         reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
3719         ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
3720
3721         ceph_con_send(&session->s_con, reply);
3722
3723         mutex_unlock(&session->s_mutex);
3724
3725         mutex_lock(&mdsc->mutex);
3726         __wake_requests(mdsc, &session->s_waiting);
3727         mutex_unlock(&mdsc->mutex);
3728
3729         up_read(&mdsc->snap_rwsem);
3730         ceph_pagelist_release(recon_state.pagelist);
3731         return;
3732
3733 fail:
3734         ceph_msg_put(reply);
3735         up_read(&mdsc->snap_rwsem);
3736         mutex_unlock(&session->s_mutex);
3737 fail_nomsg:
3738         ceph_pagelist_release(recon_state.pagelist);
3739 fail_nopagelist:
3740         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3741         return;
3742 }
3743
3744
3745 /*
3746  * compare old and new mdsmaps, kicking requests
3747  * and closing out old connections as necessary
3748  *
3749  * called under mdsc->mutex.
3750  */
3751 static void check_new_map(struct ceph_mds_client *mdsc,
3752                           struct ceph_mdsmap *newmap,
3753                           struct ceph_mdsmap *oldmap)
3754 {
3755         int i;
3756         int oldstate, newstate;
3757         struct ceph_mds_session *s;
3758
3759         dout("check_new_map new %u old %u\n",
3760              newmap->m_epoch, oldmap->m_epoch);
3761
3762         for (i = 0; i < oldmap->m_num_mds && i < mdsc->max_sessions; i++) {
3763                 if (!mdsc->sessions[i])
3764                         continue;
3765                 s = mdsc->sessions[i];
3766                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3767                 newstate = ceph_mdsmap_get_state(newmap, i);
3768
3769                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3770                      i, ceph_mds_state_name(oldstate),
3771                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3772                      ceph_mds_state_name(newstate),
3773                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3774                      ceph_session_state_name(s->s_state));
3775
3776                 if (i >= newmap->m_num_mds) {
3777                         /* force close session for stopped mds */
3778                         get_session(s);
3779                         __unregister_session(mdsc, s);
3780                         __wake_requests(mdsc, &s->s_waiting);
3781                         mutex_unlock(&mdsc->mutex);
3782
3783                         mutex_lock(&s->s_mutex);
3784                         cleanup_session_requests(mdsc, s);
3785                         remove_session_caps(s);
3786                         mutex_unlock(&s->s_mutex);
3787
3788                         ceph_put_mds_session(s);
3789
3790                         mutex_lock(&mdsc->mutex);
3791                         kick_requests(mdsc, i);
3792                         continue;
3793                 }
3794
3795                 if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
3796                            ceph_mdsmap_get_addr(newmap, i),
3797                            sizeof(struct ceph_entity_addr))) {
3798                         /* just close it */
3799                         mutex_unlock(&mdsc->mutex);
3800                         mutex_lock(&s->s_mutex);
3801                         mutex_lock(&mdsc->mutex);
3802                         ceph_con_close(&s->s_con);
3803                         mutex_unlock(&s->s_mutex);
3804                         s->s_state = CEPH_MDS_SESSION_RESTARTING;
3805                 } else if (oldstate == newstate) {
3806                         continue;  /* nothing new with this mds */
3807                 }
3808
3809                 /*
3810                  * send reconnect?
3811                  */
3812                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3813                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3814                         mutex_unlock(&mdsc->mutex);
3815                         send_mds_reconnect(mdsc, s);
3816                         mutex_lock(&mdsc->mutex);
3817                 }
3818
3819                 /*
3820                  * kick request on any mds that has gone active.
3821                  */
3822                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3823                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3824                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3825                             oldstate != CEPH_MDS_STATE_STARTING)
3826                                 pr_info("mds%d recovery completed\n", s->s_mds);
3827                         kick_requests(mdsc, i);
3828                         ceph_kick_flushing_caps(mdsc, s);
3829                         wake_up_session_caps(s, RECONNECT);
3830                 }
3831         }
3832
3833         for (i = 0; i < newmap->m_num_mds && i < mdsc->max_sessions; i++) {
3834                 s = mdsc->sessions[i];
3835                 if (!s)
3836                         continue;
3837                 if (!ceph_mdsmap_is_laggy(newmap, i))
3838                         continue;
3839                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3840                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3841                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3842                         dout(" connecting to export targets of laggy mds%d\n",
3843                              i);
3844                         __open_export_target_sessions(mdsc, s);
3845                 }
3846         }
3847 }
3848
3849
3850
3851 /*
3852  * leases
3853  */
3854
3855 /*
3856  * caller must hold session s_mutex, dentry->d_lock
3857  */
3858 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3859 {
3860         struct ceph_dentry_info *di = ceph_dentry(dentry);
3861
3862         ceph_put_mds_session(di->lease_session);
3863         di->lease_session = NULL;
3864 }
3865
3866 static void handle_lease(struct ceph_mds_client *mdsc,
3867                          struct ceph_mds_session *session,
3868                          struct ceph_msg *msg)
3869 {
3870         struct super_block *sb = mdsc->fsc->sb;
3871         struct inode *inode;
3872         struct dentry *parent, *dentry;
3873         struct ceph_dentry_info *di;
3874         int mds = session->s_mds;
3875         struct ceph_mds_lease *h = msg->front.iov_base;
3876         u32 seq;
3877         struct ceph_vino vino;
3878         struct qstr dname;
3879         int release = 0;
3880
3881         dout("handle_lease from mds%d\n", mds);
3882
3883         /* decode */
3884         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3885                 goto bad;
3886         vino.ino = le64_to_cpu(h->ino);
3887         vino.snap = CEPH_NOSNAP;
3888         seq = le32_to_cpu(h->seq);
3889         dname.len = get_unaligned_le32(h + 1);
3890         if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
3891                 goto bad;
3892         dname.name = (void *)(h + 1) + sizeof(u32);
3893
3894         /* lookup inode */
3895         inode = ceph_find_inode(sb, vino);
3896         dout("handle_lease %s, ino %llx %p %.*s\n",
3897              ceph_lease_op_name(h->action), vino.ino, inode,
3898              dname.len, dname.name);
3899
3900         mutex_lock(&session->s_mutex);
3901         session->s_seq++;
3902
3903         if (!inode) {
3904                 dout("handle_lease no inode %llx\n", vino.ino);
3905                 goto release;
3906         }
3907
3908         /* dentry */
3909         parent = d_find_alias(inode);
3910         if (!parent) {
3911                 dout("no parent dentry on inode %p\n", inode);
3912                 WARN_ON(1);
3913                 goto release;  /* hrm... */
3914         }
3915         dname.hash = full_name_hash(parent, dname.name, dname.len);
3916         dentry = d_lookup(parent, &dname);
3917         dput(parent);
3918         if (!dentry)
3919                 goto release;
3920
3921         spin_lock(&dentry->d_lock);
3922         di = ceph_dentry(dentry);
3923         switch (h->action) {
3924         case CEPH_MDS_LEASE_REVOKE:
3925                 if (di->lease_session == session) {
3926                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3927                                 h->seq = cpu_to_le32(di->lease_seq);
3928                         __ceph_mdsc_drop_dentry_lease(dentry);
3929                 }
3930                 release = 1;
3931                 break;
3932
3933         case CEPH_MDS_LEASE_RENEW:
3934                 if (di->lease_session == session &&
3935                     di->lease_gen == session->s_cap_gen &&
3936                     di->lease_renew_from &&
3937                     di->lease_renew_after == 0) {
3938                         unsigned long duration =
3939                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3940
3941                         di->lease_seq = seq;
3942                         di->time = di->lease_renew_from + duration;
3943                         di->lease_renew_after = di->lease_renew_from +
3944                                 (duration >> 1);
3945                         di->lease_renew_from = 0;
3946                 }
3947                 break;
3948         }
3949         spin_unlock(&dentry->d_lock);
3950         dput(dentry);
3951
3952         if (!release)
3953                 goto out;
3954
3955 release:
3956         /* let's just reuse the same message */
3957         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3958         ceph_msg_get(msg);
3959         ceph_con_send(&session->s_con, msg);
3960
3961 out:
3962         mutex_unlock(&session->s_mutex);
3963         /* avoid calling iput_final() in mds dispatch threads */
3964         ceph_async_iput(inode);
3965         return;
3966
3967 bad:
3968         pr_err("corrupt lease message\n");
3969         ceph_msg_dump(msg);
3970 }
3971
3972 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3973                               struct dentry *dentry, char action,
3974                               u32 seq)
3975 {
3976         struct ceph_msg *msg;
3977         struct ceph_mds_lease *lease;
3978         struct inode *dir;
3979         int len = sizeof(*lease) + sizeof(u32) + NAME_MAX;
3980
3981         dout("lease_send_msg identry %p %s to mds%d\n",
3982              dentry, ceph_lease_op_name(action), session->s_mds);
3983
3984         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3985         if (!msg)
3986                 return;
3987         lease = msg->front.iov_base;
3988         lease->action = action;
3989         lease->seq = cpu_to_le32(seq);
3990
3991         spin_lock(&dentry->d_lock);
3992         dir = d_inode(dentry->d_parent);
3993         lease->ino = cpu_to_le64(ceph_ino(dir));
3994         lease->first = lease->last = cpu_to_le64(ceph_snap(dir));
3995
3996         put_unaligned_le32(dentry->d_name.len, lease + 1);
3997         memcpy((void *)(lease + 1) + 4,
3998                dentry->d_name.name, dentry->d_name.len);
3999         spin_unlock(&dentry->d_lock);
4000         /*
4001          * if this is a preemptive lease RELEASE, no need to
4002          * flush request stream, since the actual request will
4003          * soon follow.
4004          */
4005         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
4006
4007         ceph_con_send(&session->s_con, msg);
4008 }
4009
4010 /*
4011  * lock unlock sessions, to wait ongoing session activities
4012  */
4013 static void lock_unlock_sessions(struct ceph_mds_client *mdsc)
4014 {
4015         int i;
4016
4017         mutex_lock(&mdsc->mutex);
4018         for (i = 0; i < mdsc->max_sessions; i++) {
4019                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4020                 if (!s)
4021                         continue;
4022                 mutex_unlock(&mdsc->mutex);
4023                 mutex_lock(&s->s_mutex);
4024                 mutex_unlock(&s->s_mutex);
4025                 ceph_put_mds_session(s);
4026                 mutex_lock(&mdsc->mutex);
4027         }
4028         mutex_unlock(&mdsc->mutex);
4029 }
4030
4031 static void maybe_recover_session(struct ceph_mds_client *mdsc)
4032 {
4033         struct ceph_fs_client *fsc = mdsc->fsc;
4034
4035         if (!ceph_test_mount_opt(fsc, CLEANRECOVER))
4036                 return;
4037
4038         if (READ_ONCE(fsc->mount_state) != CEPH_MOUNT_MOUNTED)
4039                 return;
4040
4041         if (!READ_ONCE(fsc->blacklisted))
4042                 return;
4043
4044         if (fsc->last_auto_reconnect &&
4045             time_before(jiffies, fsc->last_auto_reconnect + HZ * 60 * 30))
4046                 return;
4047
4048         pr_info("auto reconnect after blacklisted\n");
4049         fsc->last_auto_reconnect = jiffies;
4050         ceph_force_reconnect(fsc->sb);
4051 }
4052
4053 /*
4054  * delayed work -- periodically trim expired leases, renew caps with mds
4055  */
4056 static void schedule_delayed(struct ceph_mds_client *mdsc)
4057 {
4058         int delay = 5;
4059         unsigned hz = round_jiffies_relative(HZ * delay);
4060         schedule_delayed_work(&mdsc->delayed_work, hz);
4061 }
4062
4063 static void delayed_work(struct work_struct *work)
4064 {
4065         int i;
4066         struct ceph_mds_client *mdsc =
4067                 container_of(work, struct ceph_mds_client, delayed_work.work);
4068         int renew_interval;
4069         int renew_caps;
4070
4071         dout("mdsc delayed_work\n");
4072
4073         mutex_lock(&mdsc->mutex);
4074         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
4075         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
4076                                    mdsc->last_renew_caps);
4077         if (renew_caps)
4078                 mdsc->last_renew_caps = jiffies;
4079
4080         for (i = 0; i < mdsc->max_sessions; i++) {
4081                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4082                 if (!s)
4083                         continue;
4084                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
4085                         dout("resending session close request for mds%d\n",
4086                              s->s_mds);
4087                         request_close_session(mdsc, s);
4088                         ceph_put_mds_session(s);
4089                         continue;
4090                 }
4091                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
4092                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
4093                                 s->s_state = CEPH_MDS_SESSION_HUNG;
4094                                 pr_info("mds%d hung\n", s->s_mds);
4095                         }
4096                 }
4097                 if (s->s_state == CEPH_MDS_SESSION_NEW ||
4098                     s->s_state == CEPH_MDS_SESSION_RESTARTING ||
4099                     s->s_state == CEPH_MDS_SESSION_REJECTED) {
4100                         /* this mds is failed or recovering, just wait */
4101                         ceph_put_mds_session(s);
4102                         continue;
4103                 }
4104                 mutex_unlock(&mdsc->mutex);
4105
4106                 mutex_lock(&s->s_mutex);
4107                 if (renew_caps)
4108                         send_renew_caps(mdsc, s);
4109                 else
4110                         ceph_con_keepalive(&s->s_con);
4111                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4112                     s->s_state == CEPH_MDS_SESSION_HUNG)
4113                         ceph_send_cap_releases(mdsc, s);
4114                 mutex_unlock(&s->s_mutex);
4115                 ceph_put_mds_session(s);
4116
4117                 mutex_lock(&mdsc->mutex);
4118         }
4119         mutex_unlock(&mdsc->mutex);
4120
4121         ceph_check_delayed_caps(mdsc);
4122
4123         ceph_queue_cap_reclaim_work(mdsc);
4124
4125         ceph_trim_snapid_map(mdsc);
4126
4127         maybe_recover_session(mdsc);
4128
4129         schedule_delayed(mdsc);
4130 }
4131
4132 int ceph_mdsc_init(struct ceph_fs_client *fsc)
4133
4134 {
4135         struct ceph_mds_client *mdsc;
4136
4137         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
4138         if (!mdsc)
4139                 return -ENOMEM;
4140         mdsc->fsc = fsc;
4141         mutex_init(&mdsc->mutex);
4142         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
4143         if (!mdsc->mdsmap) {
4144                 kfree(mdsc);
4145                 return -ENOMEM;
4146         }
4147
4148         fsc->mdsc = mdsc;
4149         init_completion(&mdsc->safe_umount_waiters);
4150         init_waitqueue_head(&mdsc->session_close_wq);
4151         INIT_LIST_HEAD(&mdsc->waiting_for_map);
4152         mdsc->sessions = NULL;
4153         atomic_set(&mdsc->num_sessions, 0);
4154         mdsc->max_sessions = 0;
4155         mdsc->stopping = 0;
4156         atomic64_set(&mdsc->quotarealms_count, 0);
4157         mdsc->quotarealms_inodes = RB_ROOT;
4158         mutex_init(&mdsc->quotarealms_inodes_mutex);
4159         mdsc->last_snap_seq = 0;
4160         init_rwsem(&mdsc->snap_rwsem);
4161         mdsc->snap_realms = RB_ROOT;
4162         INIT_LIST_HEAD(&mdsc->snap_empty);
4163         mdsc->num_snap_realms = 0;
4164         spin_lock_init(&mdsc->snap_empty_lock);
4165         mdsc->last_tid = 0;
4166         mdsc->oldest_tid = 0;
4167         mdsc->request_tree = RB_ROOT;
4168         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
4169         mdsc->last_renew_caps = jiffies;
4170         INIT_LIST_HEAD(&mdsc->cap_delay_list);
4171         spin_lock_init(&mdsc->cap_delay_lock);
4172         INIT_LIST_HEAD(&mdsc->snap_flush_list);
4173         spin_lock_init(&mdsc->snap_flush_lock);
4174         mdsc->last_cap_flush_tid = 1;
4175         INIT_LIST_HEAD(&mdsc->cap_flush_list);
4176         INIT_LIST_HEAD(&mdsc->cap_dirty);
4177         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
4178         mdsc->num_cap_flushing = 0;
4179         spin_lock_init(&mdsc->cap_dirty_lock);
4180         init_waitqueue_head(&mdsc->cap_flushing_wq);
4181         INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
4182         atomic_set(&mdsc->cap_reclaim_pending, 0);
4183
4184         spin_lock_init(&mdsc->dentry_list_lock);
4185         INIT_LIST_HEAD(&mdsc->dentry_leases);
4186         INIT_LIST_HEAD(&mdsc->dentry_dir_leases);
4187
4188         ceph_caps_init(mdsc);
4189         ceph_adjust_caps_max_min(mdsc, fsc->mount_options);
4190
4191         spin_lock_init(&mdsc->snapid_map_lock);
4192         mdsc->snapid_map_tree = RB_ROOT;
4193         INIT_LIST_HEAD(&mdsc->snapid_map_lru);
4194
4195         init_rwsem(&mdsc->pool_perm_rwsem);
4196         mdsc->pool_perm_tree = RB_ROOT;
4197
4198         strscpy(mdsc->nodename, utsname()->nodename,
4199                 sizeof(mdsc->nodename));
4200         return 0;
4201 }
4202
4203 /*
4204  * Wait for safe replies on open mds requests.  If we time out, drop
4205  * all requests from the tree to avoid dangling dentry refs.
4206  */
4207 static void wait_requests(struct ceph_mds_client *mdsc)
4208 {
4209         struct ceph_options *opts = mdsc->fsc->client->options;
4210         struct ceph_mds_request *req;
4211
4212         mutex_lock(&mdsc->mutex);
4213         if (__get_oldest_req(mdsc)) {
4214                 mutex_unlock(&mdsc->mutex);
4215
4216                 dout("wait_requests waiting for requests\n");
4217                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
4218                                     ceph_timeout_jiffies(opts->mount_timeout));
4219
4220                 /* tear down remaining requests */
4221                 mutex_lock(&mdsc->mutex);
4222                 while ((req = __get_oldest_req(mdsc))) {
4223                         dout("wait_requests timed out on tid %llu\n",
4224                              req->r_tid);
4225                         list_del_init(&req->r_wait);
4226                         __unregister_request(mdsc, req);
4227                 }
4228         }
4229         mutex_unlock(&mdsc->mutex);
4230         dout("wait_requests done\n");
4231 }
4232
4233 /*
4234  * called before mount is ro, and before dentries are torn down.
4235  * (hmm, does this still race with new lookups?)
4236  */
4237 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
4238 {
4239         dout("pre_umount\n");
4240         mdsc->stopping = 1;
4241
4242         lock_unlock_sessions(mdsc);
4243         ceph_flush_dirty_caps(mdsc);
4244         wait_requests(mdsc);
4245
4246         /*
4247          * wait for reply handlers to drop their request refs and
4248          * their inode/dcache refs
4249          */
4250         ceph_msgr_flush();
4251
4252         ceph_cleanup_quotarealms_inodes(mdsc);
4253 }
4254
4255 /*
4256  * wait for all write mds requests to flush.
4257  */
4258 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
4259 {
4260         struct ceph_mds_request *req = NULL, *nextreq;
4261         struct rb_node *n;
4262
4263         mutex_lock(&mdsc->mutex);
4264         dout("wait_unsafe_requests want %lld\n", want_tid);
4265 restart:
4266         req = __get_oldest_req(mdsc);
4267         while (req && req->r_tid <= want_tid) {
4268                 /* find next request */
4269                 n = rb_next(&req->r_node);
4270                 if (n)
4271                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
4272                 else
4273                         nextreq = NULL;
4274                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
4275                     (req->r_op & CEPH_MDS_OP_WRITE)) {
4276                         /* write op */
4277                         ceph_mdsc_get_request(req);
4278                         if (nextreq)
4279                                 ceph_mdsc_get_request(nextreq);
4280                         mutex_unlock(&mdsc->mutex);
4281                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
4282                              req->r_tid, want_tid);
4283                         wait_for_completion(&req->r_safe_completion);
4284                         mutex_lock(&mdsc->mutex);
4285                         ceph_mdsc_put_request(req);
4286                         if (!nextreq)
4287                                 break;  /* next dne before, so we're done! */
4288                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
4289                                 /* next request was removed from tree */
4290                                 ceph_mdsc_put_request(nextreq);
4291                                 goto restart;
4292                         }
4293                         ceph_mdsc_put_request(nextreq);  /* won't go away */
4294                 }
4295                 req = nextreq;
4296         }
4297         mutex_unlock(&mdsc->mutex);
4298         dout("wait_unsafe_requests done\n");
4299 }
4300
4301 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
4302 {
4303         u64 want_tid, want_flush;
4304
4305         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4306                 return;
4307
4308         dout("sync\n");
4309         mutex_lock(&mdsc->mutex);
4310         want_tid = mdsc->last_tid;
4311         mutex_unlock(&mdsc->mutex);
4312
4313         ceph_flush_dirty_caps(mdsc);
4314         spin_lock(&mdsc->cap_dirty_lock);
4315         want_flush = mdsc->last_cap_flush_tid;
4316         if (!list_empty(&mdsc->cap_flush_list)) {
4317                 struct ceph_cap_flush *cf =
4318                         list_last_entry(&mdsc->cap_flush_list,
4319                                         struct ceph_cap_flush, g_list);
4320                 cf->wake = true;
4321         }
4322         spin_unlock(&mdsc->cap_dirty_lock);
4323
4324         dout("sync want tid %lld flush_seq %lld\n",
4325              want_tid, want_flush);
4326
4327         wait_unsafe_requests(mdsc, want_tid);
4328         wait_caps_flush(mdsc, want_flush);
4329 }
4330
4331 /*
4332  * true if all sessions are closed, or we force unmount
4333  */
4334 static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
4335 {
4336         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4337                 return true;
4338         return atomic_read(&mdsc->num_sessions) <= skipped;
4339 }
4340
4341 /*
4342  * called after sb is ro.
4343  */
4344 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
4345 {
4346         struct ceph_options *opts = mdsc->fsc->client->options;
4347         struct ceph_mds_session *session;
4348         int i;
4349         int skipped = 0;
4350
4351         dout("close_sessions\n");
4352
4353         /* close sessions */
4354         mutex_lock(&mdsc->mutex);
4355         for (i = 0; i < mdsc->max_sessions; i++) {
4356                 session = __ceph_lookup_mds_session(mdsc, i);
4357                 if (!session)
4358                         continue;
4359                 mutex_unlock(&mdsc->mutex);
4360                 mutex_lock(&session->s_mutex);
4361                 if (__close_session(mdsc, session) <= 0)
4362                         skipped++;
4363                 mutex_unlock(&session->s_mutex);
4364                 ceph_put_mds_session(session);
4365                 mutex_lock(&mdsc->mutex);
4366         }
4367         mutex_unlock(&mdsc->mutex);
4368
4369         dout("waiting for sessions to close\n");
4370         wait_event_timeout(mdsc->session_close_wq,
4371                            done_closing_sessions(mdsc, skipped),
4372                            ceph_timeout_jiffies(opts->mount_timeout));
4373
4374         /* tear down remaining sessions */
4375         mutex_lock(&mdsc->mutex);
4376         for (i = 0; i < mdsc->max_sessions; i++) {
4377                 if (mdsc->sessions[i]) {
4378                         session = get_session(mdsc->sessions[i]);
4379                         __unregister_session(mdsc, session);
4380                         mutex_unlock(&mdsc->mutex);
4381                         mutex_lock(&session->s_mutex);
4382                         remove_session_caps(session);
4383                         mutex_unlock(&session->s_mutex);
4384                         ceph_put_mds_session(session);
4385                         mutex_lock(&mdsc->mutex);
4386                 }
4387         }
4388         WARN_ON(!list_empty(&mdsc->cap_delay_list));
4389         mutex_unlock(&mdsc->mutex);
4390
4391         ceph_cleanup_snapid_map(mdsc);
4392         ceph_cleanup_empty_realms(mdsc);
4393
4394         cancel_work_sync(&mdsc->cap_reclaim_work);
4395         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4396
4397         dout("stopped\n");
4398 }
4399
4400 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
4401 {
4402         struct ceph_mds_session *session;
4403         int mds;
4404
4405         dout("force umount\n");
4406
4407         mutex_lock(&mdsc->mutex);
4408         for (mds = 0; mds < mdsc->max_sessions; mds++) {
4409                 session = __ceph_lookup_mds_session(mdsc, mds);
4410                 if (!session)
4411                         continue;
4412
4413                 if (session->s_state == CEPH_MDS_SESSION_REJECTED)
4414                         __unregister_session(mdsc, session);
4415                 __wake_requests(mdsc, &session->s_waiting);
4416                 mutex_unlock(&mdsc->mutex);
4417
4418                 mutex_lock(&session->s_mutex);
4419                 __close_session(mdsc, session);
4420                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
4421                         cleanup_session_requests(mdsc, session);
4422                         remove_session_caps(session);
4423                 }
4424                 mutex_unlock(&session->s_mutex);
4425                 ceph_put_mds_session(session);
4426
4427                 mutex_lock(&mdsc->mutex);
4428                 kick_requests(mdsc, mds);
4429         }
4430         __wake_requests(mdsc, &mdsc->waiting_for_map);
4431         mutex_unlock(&mdsc->mutex);
4432 }
4433
4434 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
4435 {
4436         dout("stop\n");
4437         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4438         if (mdsc->mdsmap)
4439                 ceph_mdsmap_destroy(mdsc->mdsmap);
4440         kfree(mdsc->sessions);
4441         ceph_caps_finalize(mdsc);
4442         ceph_pool_perm_destroy(mdsc);
4443 }
4444
4445 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
4446 {
4447         struct ceph_mds_client *mdsc = fsc->mdsc;
4448         dout("mdsc_destroy %p\n", mdsc);
4449
4450         if (!mdsc)
4451                 return;
4452
4453         /* flush out any connection work with references to us */
4454         ceph_msgr_flush();
4455
4456         ceph_mdsc_stop(mdsc);
4457
4458         fsc->mdsc = NULL;
4459         kfree(mdsc);
4460         dout("mdsc_destroy %p done\n", mdsc);
4461 }
4462
4463 void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4464 {
4465         struct ceph_fs_client *fsc = mdsc->fsc;
4466         const char *mds_namespace = fsc->mount_options->mds_namespace;
4467         void *p = msg->front.iov_base;
4468         void *end = p + msg->front.iov_len;
4469         u32 epoch;
4470         u32 map_len;
4471         u32 num_fs;
4472         u32 mount_fscid = (u32)-1;
4473         u8 struct_v, struct_cv;
4474         int err = -EINVAL;
4475
4476         ceph_decode_need(&p, end, sizeof(u32), bad);
4477         epoch = ceph_decode_32(&p);
4478
4479         dout("handle_fsmap epoch %u\n", epoch);
4480
4481         ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4482         struct_v = ceph_decode_8(&p);
4483         struct_cv = ceph_decode_8(&p);
4484         map_len = ceph_decode_32(&p);
4485
4486         ceph_decode_need(&p, end, sizeof(u32) * 3, bad);
4487         p += sizeof(u32) * 2; /* skip epoch and legacy_client_fscid */
4488
4489         num_fs = ceph_decode_32(&p);
4490         while (num_fs-- > 0) {
4491                 void *info_p, *info_end;
4492                 u32 info_len;
4493                 u8 info_v, info_cv;
4494                 u32 fscid, namelen;
4495
4496                 ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4497                 info_v = ceph_decode_8(&p);
4498                 info_cv = ceph_decode_8(&p);
4499                 info_len = ceph_decode_32(&p);
4500                 ceph_decode_need(&p, end, info_len, bad);
4501                 info_p = p;
4502                 info_end = p + info_len;
4503                 p = info_end;
4504
4505                 ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
4506                 fscid = ceph_decode_32(&info_p);
4507                 namelen = ceph_decode_32(&info_p);
4508                 ceph_decode_need(&info_p, info_end, namelen, bad);
4509
4510                 if (mds_namespace &&
4511                     strlen(mds_namespace) == namelen &&
4512                     !strncmp(mds_namespace, (char *)info_p, namelen)) {
4513                         mount_fscid = fscid;
4514                         break;
4515                 }
4516         }
4517
4518         ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
4519         if (mount_fscid != (u32)-1) {
4520                 fsc->client->monc.fs_cluster_id = mount_fscid;
4521                 ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
4522                                    0, true);
4523                 ceph_monc_renew_subs(&fsc->client->monc);
4524         } else {
4525                 err = -ENOENT;
4526                 goto err_out;
4527         }
4528         return;
4529
4530 bad:
4531         pr_err("error decoding fsmap\n");
4532 err_out:
4533         mutex_lock(&mdsc->mutex);
4534         mdsc->mdsmap_err = err;
4535         __wake_requests(mdsc, &mdsc->waiting_for_map);
4536         mutex_unlock(&mdsc->mutex);
4537 }
4538
4539 /*
4540  * handle mds map update.
4541  */
4542 void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4543 {
4544         u32 epoch;
4545         u32 maplen;
4546         void *p = msg->front.iov_base;
4547         void *end = p + msg->front.iov_len;
4548         struct ceph_mdsmap *newmap, *oldmap;
4549         struct ceph_fsid fsid;
4550         int err = -EINVAL;
4551
4552         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
4553         ceph_decode_copy(&p, &fsid, sizeof(fsid));
4554         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
4555                 return;
4556         epoch = ceph_decode_32(&p);
4557         maplen = ceph_decode_32(&p);
4558         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
4559
4560         /* do we need it? */
4561         mutex_lock(&mdsc->mutex);
4562         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
4563                 dout("handle_map epoch %u <= our %u\n",
4564                      epoch, mdsc->mdsmap->m_epoch);
4565                 mutex_unlock(&mdsc->mutex);
4566                 return;
4567         }
4568
4569         newmap = ceph_mdsmap_decode(&p, end);
4570         if (IS_ERR(newmap)) {
4571                 err = PTR_ERR(newmap);
4572                 goto bad_unlock;
4573         }
4574
4575         /* swap into place */
4576         if (mdsc->mdsmap) {
4577                 oldmap = mdsc->mdsmap;
4578                 mdsc->mdsmap = newmap;
4579                 check_new_map(mdsc, newmap, oldmap);
4580                 ceph_mdsmap_destroy(oldmap);
4581         } else {
4582                 mdsc->mdsmap = newmap;  /* first mds map */
4583         }
4584         mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
4585                                         MAX_LFS_FILESIZE);
4586
4587         __wake_requests(mdsc, &mdsc->waiting_for_map);
4588         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
4589                           mdsc->mdsmap->m_epoch);
4590
4591         mutex_unlock(&mdsc->mutex);
4592         schedule_delayed(mdsc);
4593         return;
4594
4595 bad_unlock:
4596         mutex_unlock(&mdsc->mutex);
4597 bad:
4598         pr_err("error decoding mdsmap %d\n", err);
4599         return;
4600 }
4601
4602 static struct ceph_connection *con_get(struct ceph_connection *con)
4603 {
4604         struct ceph_mds_session *s = con->private;
4605
4606         if (get_session(s)) {
4607                 dout("mdsc con_get %p ok (%d)\n", s, refcount_read(&s->s_ref));
4608                 return con;
4609         }
4610         dout("mdsc con_get %p FAIL\n", s);
4611         return NULL;
4612 }
4613
4614 static void con_put(struct ceph_connection *con)
4615 {
4616         struct ceph_mds_session *s = con->private;
4617
4618         dout("mdsc con_put %p (%d)\n", s, refcount_read(&s->s_ref) - 1);
4619         ceph_put_mds_session(s);
4620 }
4621
4622 /*
4623  * if the client is unresponsive for long enough, the mds will kill
4624  * the session entirely.
4625  */
4626 static void peer_reset(struct ceph_connection *con)
4627 {
4628         struct ceph_mds_session *s = con->private;
4629         struct ceph_mds_client *mdsc = s->s_mdsc;
4630
4631         pr_warn("mds%d closed our session\n", s->s_mds);
4632         send_mds_reconnect(mdsc, s);
4633 }
4634
4635 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
4636 {
4637         struct ceph_mds_session *s = con->private;
4638         struct ceph_mds_client *mdsc = s->s_mdsc;
4639         int type = le16_to_cpu(msg->hdr.type);
4640
4641         mutex_lock(&mdsc->mutex);
4642         if (__verify_registered_session(mdsc, s) < 0) {
4643                 mutex_unlock(&mdsc->mutex);
4644                 goto out;
4645         }
4646         mutex_unlock(&mdsc->mutex);
4647
4648         switch (type) {
4649         case CEPH_MSG_MDS_MAP:
4650                 ceph_mdsc_handle_mdsmap(mdsc, msg);
4651                 break;
4652         case CEPH_MSG_FS_MAP_USER:
4653                 ceph_mdsc_handle_fsmap(mdsc, msg);
4654                 break;
4655         case CEPH_MSG_CLIENT_SESSION:
4656                 handle_session(s, msg);
4657                 break;
4658         case CEPH_MSG_CLIENT_REPLY:
4659                 handle_reply(s, msg);
4660                 break;
4661         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
4662                 handle_forward(mdsc, s, msg);
4663                 break;
4664         case CEPH_MSG_CLIENT_CAPS:
4665                 ceph_handle_caps(s, msg);
4666                 break;
4667         case CEPH_MSG_CLIENT_SNAP:
4668                 ceph_handle_snap(mdsc, s, msg);
4669                 break;
4670         case CEPH_MSG_CLIENT_LEASE:
4671                 handle_lease(mdsc, s, msg);
4672                 break;
4673         case CEPH_MSG_CLIENT_QUOTA:
4674                 ceph_handle_quota(mdsc, s, msg);
4675                 break;
4676
4677         default:
4678                 pr_err("received unknown message type %d %s\n", type,
4679                        ceph_msg_type_name(type));
4680         }
4681 out:
4682         ceph_msg_put(msg);
4683 }
4684
4685 /*
4686  * authentication
4687  */
4688
4689 /*
4690  * Note: returned pointer is the address of a structure that's
4691  * managed separately.  Caller must *not* attempt to free it.
4692  */
4693 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
4694                                         int *proto, int force_new)
4695 {
4696         struct ceph_mds_session *s = con->private;
4697         struct ceph_mds_client *mdsc = s->s_mdsc;
4698         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4699         struct ceph_auth_handshake *auth = &s->s_auth;
4700
4701         if (force_new && auth->authorizer) {
4702                 ceph_auth_destroy_authorizer(auth->authorizer);
4703                 auth->authorizer = NULL;
4704         }
4705         if (!auth->authorizer) {
4706                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4707                                                       auth);
4708                 if (ret)
4709                         return ERR_PTR(ret);
4710         } else {
4711                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4712                                                       auth);
4713                 if (ret)
4714                         return ERR_PTR(ret);
4715         }
4716         *proto = ac->protocol;
4717
4718         return auth;
4719 }
4720
4721 static int add_authorizer_challenge(struct ceph_connection *con,
4722                                     void *challenge_buf, int challenge_buf_len)
4723 {
4724         struct ceph_mds_session *s = con->private;
4725         struct ceph_mds_client *mdsc = s->s_mdsc;
4726         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4727
4728         return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
4729                                             challenge_buf, challenge_buf_len);
4730 }
4731
4732 static int verify_authorizer_reply(struct ceph_connection *con)
4733 {
4734         struct ceph_mds_session *s = con->private;
4735         struct ceph_mds_client *mdsc = s->s_mdsc;
4736         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4737
4738         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer);
4739 }
4740
4741 static int invalidate_authorizer(struct ceph_connection *con)
4742 {
4743         struct ceph_mds_session *s = con->private;
4744         struct ceph_mds_client *mdsc = s->s_mdsc;
4745         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4746
4747         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
4748
4749         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
4750 }
4751
4752 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
4753                                 struct ceph_msg_header *hdr, int *skip)
4754 {
4755         struct ceph_msg *msg;
4756         int type = (int) le16_to_cpu(hdr->type);
4757         int front_len = (int) le32_to_cpu(hdr->front_len);
4758
4759         if (con->in_msg)
4760                 return con->in_msg;
4761
4762         *skip = 0;
4763         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
4764         if (!msg) {
4765                 pr_err("unable to allocate msg type %d len %d\n",
4766                        type, front_len);
4767                 return NULL;
4768         }
4769
4770         return msg;
4771 }
4772
4773 static int mds_sign_message(struct ceph_msg *msg)
4774 {
4775        struct ceph_mds_session *s = msg->con->private;
4776        struct ceph_auth_handshake *auth = &s->s_auth;
4777
4778        return ceph_auth_sign_message(auth, msg);
4779 }
4780
4781 static int mds_check_message_signature(struct ceph_msg *msg)
4782 {
4783        struct ceph_mds_session *s = msg->con->private;
4784        struct ceph_auth_handshake *auth = &s->s_auth;
4785
4786        return ceph_auth_check_message_signature(auth, msg);
4787 }
4788
4789 static const struct ceph_connection_operations mds_con_ops = {
4790         .get = con_get,
4791         .put = con_put,
4792         .dispatch = dispatch,
4793         .get_authorizer = get_authorizer,
4794         .add_authorizer_challenge = add_authorizer_challenge,
4795         .verify_authorizer_reply = verify_authorizer_reply,
4796         .invalidate_authorizer = invalidate_authorizer,
4797         .peer_reset = peer_reset,
4798         .alloc_msg = mds_alloc_msg,
4799         .sign_message = mds_sign_message,
4800         .check_message_signature = mds_check_message_signature,
4801 };
4802
4803 /* eof */