fs/ceph/mds_client.c

   1 #include <linux/ceph/ceph_debug.h>
   2
   3 #include <linux/fs.h>
   4 #include <linux/wait.h>
   5 #include <linux/slab.h>
   6 #include <linux/gfp.h>
   7 #include <linux/sched.h>
   8 #include <linux/debugfs.h>
   9 #include <linux/seq_file.h>
  10 #include <linux/utsname.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 /*
  24  * A cluster of MDS (metadata server) daemons is responsible for
  25  * managing the file system namespace (the directory hierarchy and
  26  * inodes) and for coordinating shared access to storage.  Metadata is
  27  * partitioning hierarchically across a number of servers, and that
  28  * partition varies over time as the cluster adjusts the distribution
  29  * in order to balance load.
  30  *
  31  * The MDS client is primarily responsible to managing synchronous
  32  * metadata requests for operations like open, unlink, and so forth.
  33  * If there is a MDS failure, we find out about it when we (possibly
  34  * request and) receive a new MDS map, and can resubmit affected
  35  * requests.
  36  *
  37  * For the most part, though, we take advantage of a lossless
  38  * communications channel to the MDS, and do not need to worry about
  39  * timing out or resubmitting requests.
  40  *
  41  * We maintain a stateful "session" with each MDS we interact with.
  42  * Within each session, we sent periodic heartbeat messages to ensure
  43  * any capabilities or leases we have been issues remain valid.  If
  44  * the session times out and goes stale, our leases and capabilities
  45  * are no longer valid.
  46  */
  47
  48 struct ceph_reconnect_state {
  49         int nr_caps;
  50         struct ceph_pagelist *pagelist;
  51         bool flock;
  52 };
  53
  54 static void __wake_requests(struct ceph_mds_client *mdsc,
  55                             struct list_head *head);
  56
  57 static const struct ceph_connection_operations mds_con_ops;
  58
  59
  60 /*
  61  * mds reply parsing
  62  */
  63
  64 /*
  65  * parse individual inode info
  66  */
  67 static int parse_reply_info_in(void **p, void *end,
  68                                struct ceph_mds_reply_info_in *info,
  69                                u64 features)
  70 {
  71         int err = -EIO;
  72
  73         info->in = *p;
  74         *p += sizeof(struct ceph_mds_reply_inode) +
  75                 sizeof(*info->in->fragtree.splits) *
  76                 le32_to_cpu(info->in->fragtree.nsplits);
  77
  78         ceph_decode_32_safe(p, end, info->symlink_len, bad);
  79         ceph_decode_need(p, end, info->symlink_len, bad);
  80         info->symlink = *p;
  81         *p += info->symlink_len;
  82
  83         if (features & CEPH_FEATURE_DIRLAYOUTHASH)
  84                 ceph_decode_copy_safe(p, end, &info->dir_layout,
  85                                       sizeof(info->dir_layout), bad);
  86         else
  87                 memset(&info->dir_layout, 0, sizeof(info->dir_layout));
  88
  89         ceph_decode_32_safe(p, end, info->xattr_len, bad);
  90         ceph_decode_need(p, end, info->xattr_len, bad);
  91         info->xattr_data = *p;
  92         *p += info->xattr_len;
  93
  94         if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
  95                 ceph_decode_64_safe(p, end, info->inline_version, bad);
  96                 ceph_decode_32_safe(p, end, info->inline_len, bad);
  97                 ceph_decode_need(p, end, info->inline_len, bad);
  98                 info->inline_data = *p;
  99                 *p += info->inline_len;
 100         } else
 101                 info->inline_version = CEPH_INLINE_NONE;
 102
 103         info->pool_ns_len = 0;
 104         info->pool_ns_data = NULL;
 105         if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 106                 ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 107                 if (info->pool_ns_len > 0) {
 108                         ceph_decode_need(p, end, info->pool_ns_len, bad);
 109                         info->pool_ns_data = *p;
 110                         *p += info->pool_ns_len;
 111                 }
 112         }
 113
 114         return 0;
 115 bad:
 116         return err;
 117 }
 118
 119 /*
 120  * parse a normal reply, which may contain a (dir+)dentry and/or a
 121  * target inode.
 122  */
 123 static int parse_reply_info_trace(void **p, void *end,
 124                                   struct ceph_mds_reply_info_parsed *info,
 125                                   u64 features)
 126 {
 127         int err;
 128
 129         if (info->head->is_dentry) {
 130                 err = parse_reply_info_in(p, end, &info->diri, features);
 131                 if (err < 0)
 132                         goto out_bad;
 133
 134                 if (unlikely(*p + sizeof(*info->dirfrag) > end))
 135                         goto bad;
 136                 info->dirfrag = *p;
 137                 *p += sizeof(*info->dirfrag) +
 138                         sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 139                 if (unlikely(*p > end))
 140                         goto bad;
 141
 142                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 143                 ceph_decode_need(p, end, info->dname_len, bad);
 144                 info->dname = *p;
 145                 *p += info->dname_len;
 146                 info->dlease = *p;
 147                 *p += sizeof(*info->dlease);
 148         }
 149
 150         if (info->head->is_target) {
 151                 err = parse_reply_info_in(p, end, &info->targeti, features);
 152                 if (err < 0)
 153                         goto out_bad;
 154         }
 155
 156         if (unlikely(*p != end))
 157                 goto bad;
 158         return 0;
 159
 160 bad:
 161         err = -EIO;
 162 out_bad:
 163         pr_err("problem parsing mds trace %d\n", err);
 164         return err;
 165 }
 166
 167 /*
 168  * parse readdir results
 169  */
 170 static int parse_reply_info_dir(void **p, void *end,
 171                                 struct ceph_mds_reply_info_parsed *info,
 172                                 u64 features)
 173 {
 174         u32 num, i = 0;
 175         int err;
 176
 177         info->dir_dir = *p;
 178         if (*p + sizeof(*info->dir_dir) > end)
 179                 goto bad;
 180         *p += sizeof(*info->dir_dir) +
 181                 sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 182         if (*p > end)
 183                 goto bad;
 184
 185         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 186         num = ceph_decode_32(p);
 187         {
 188                 u16 flags = ceph_decode_16(p);
 189                 info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 190                 info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 191                 info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 192         }
 193         if (num == 0)
 194                 goto done;
 195
 196         BUG_ON(!info->dir_entries);
 197         if ((unsigned long)(info->dir_entries + num) >
 198             (unsigned long)info->dir_entries + info->dir_buf_size) {
 199                 pr_err("dir contents are larger than expected\n");
 200                 WARN_ON(1);
 201                 goto bad;
 202         }
 203
 204         info->dir_nr = num;
 205         while (num) {
 206                 struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 207                 /* dentry */
 208                 ceph_decode_need(p, end, sizeof(u32)*2, bad);
 209                 rde->name_len = ceph_decode_32(p);
 210                 ceph_decode_need(p, end, rde->name_len, bad);
 211                 rde->name = *p;
 212                 *p += rde->name_len;
 213                 dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 214                 rde->lease = *p;
 215                 *p += sizeof(struct ceph_mds_reply_lease);
 216
 217                 /* inode */
 218                 err = parse_reply_info_in(p, end, &rde->inode, features);
 219                 if (err < 0)
 220                         goto out_bad;
 221                 /* ceph_readdir_prepopulate() will update it */
 222                 rde->offset = 0;
 223                 i++;
 224                 num--;
 225         }
 226
 227 done:
 228         if (*p != end)
 229                 goto bad;
 230         return 0;
 231
 232 bad:
 233         err = -EIO;
 234 out_bad:
 235         pr_err("problem parsing dir contents %d\n", err);
 236         return err;
 237 }
 238
 239 /*
 240  * parse fcntl F_GETLK results
 241  */
 242 static int parse_reply_info_filelock(void **p, void *end,
 243                                      struct ceph_mds_reply_info_parsed *info,
 244                                      u64 features)
 245 {
 246         if (*p + sizeof(*info->filelock_reply) > end)
 247                 goto bad;
 248
 249         info->filelock_reply = *p;
 250         *p += sizeof(*info->filelock_reply);
 251
 252         if (unlikely(*p != end))
 253                 goto bad;
 254         return 0;
 255
 256 bad:
 257         return -EIO;
 258 }
 259
 260 /*
 261  * parse create results
 262  */
 263 static int parse_reply_info_create(void **p, void *end,
 264                                   struct ceph_mds_reply_info_parsed *info,
 265                                   u64 features)
 266 {
 267         if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 268                 if (*p == end) {
 269                         info->has_create_ino = false;
 270                 } else {
 271                         info->has_create_ino = true;
 272                         info->ino = ceph_decode_64(p);
 273                 }
 274         }
 275
 276         if (unlikely(*p != end))
 277                 goto bad;
 278         return 0;
 279
 280 bad:
 281         return -EIO;
 282 }
 283
 284 /*
 285  * parse extra results
 286  */
 287 static int parse_reply_info_extra(void **p, void *end,
 288                                   struct ceph_mds_reply_info_parsed *info,
 289                                   u64 features)
 290 {
 291         if (info->head->op == CEPH_MDS_OP_GETFILELOCK)
 292                 return parse_reply_info_filelock(p, end, info, features);
 293         else if (info->head->op == CEPH_MDS_OP_READDIR ||
 294                  info->head->op == CEPH_MDS_OP_LSSNAP)
 295                 return parse_reply_info_dir(p, end, info, features);
 296         else if (info->head->op == CEPH_MDS_OP_CREATE)
 297                 return parse_reply_info_create(p, end, info, features);
 298         else
 299                 return -EIO;
 300 }
 301
 302 /*
 303  * parse entire mds reply
 304  */
 305 static int parse_reply_info(struct ceph_msg *msg,
 306                             struct ceph_mds_reply_info_parsed *info,
 307                             u64 features)
 308 {
 309         void *p, *end;
 310         u32 len;
 311         int err;
 312
 313         info->head = msg->front.iov_base;
 314         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 315         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 316
 317         /* trace */
 318         ceph_decode_32_safe(&p, end, len, bad);
 319         if (len > 0) {
 320                 ceph_decode_need(&p, end, len, bad);
 321                 err = parse_reply_info_trace(&p, p+len, info, features);
 322                 if (err < 0)
 323                         goto out_bad;
 324         }
 325
 326         /* extra */
 327         ceph_decode_32_safe(&p, end, len, bad);
 328         if (len > 0) {
 329                 ceph_decode_need(&p, end, len, bad);
 330                 err = parse_reply_info_extra(&p, p+len, info, features);
 331                 if (err < 0)
 332                         goto out_bad;
 333         }
 334
 335         /* snap blob */
 336         ceph_decode_32_safe(&p, end, len, bad);
 337         info->snapblob_len = len;
 338         info->snapblob = p;
 339         p += len;
 340
 341         if (p != end)
 342                 goto bad;
 343         return 0;
 344
 345 bad:
 346         err = -EIO;
 347 out_bad:
 348         pr_err("mds parse_reply err %d\n", err);
 349         return err;
 350 }
 351
 352 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 353 {
 354         if (!info->dir_entries)
 355                 return;
 356         free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 357 }
 358
 359
 360 /*
 361  * sessions
 362  */
 363 const char *ceph_session_state_name(int s)
 364 {
 365         switch (s) {
 366         case CEPH_MDS_SESSION_NEW: return "new";
 367         case CEPH_MDS_SESSION_OPENING: return "opening";
 368         case CEPH_MDS_SESSION_OPEN: return "open";
 369         case CEPH_MDS_SESSION_HUNG: return "hung";
 370         case CEPH_MDS_SESSION_CLOSING: return "closing";
 371         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 372         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 373         default: return "???";
 374         }
 375 }
 376
 377 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 378 {
 379         if (atomic_inc_not_zero(&s->s_ref)) {
 380                 dout("mdsc get_session %p %d -> %d\n", s,
 381                      atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
 382                 return s;
 383         } else {
 384                 dout("mdsc get_session %p 0 -- FAIL", s);
 385                 return NULL;
 386         }
 387 }
 388
 389 void ceph_put_mds_session(struct ceph_mds_session *s)
 390 {
 391         dout("mdsc put_session %p %d -> %d\n", s,
 392              atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
 393         if (atomic_dec_and_test(&s->s_ref)) {
 394                 if (s->s_auth.authorizer)
 395                         ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 396                 kfree(s);
 397         }
 398 }
 399
 400 /*
 401  * called under mdsc->mutex
 402  */
 403 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 404                                                    int mds)
 405 {
 406         struct ceph_mds_session *session;
 407
 408         if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
 409                 return NULL;
 410         session = mdsc->sessions[mds];
 411         dout("lookup_mds_session %p %d\n", session,
 412              atomic_read(&session->s_ref));
 413         get_session(session);
 414         return session;
 415 }
 416
 417 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 418 {
 419         if (mds >= mdsc->max_sessions)
 420                 return false;
 421         return mdsc->sessions[mds];
 422 }
 423
 424 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 425                                        struct ceph_mds_session *s)
 426 {
 427         if (s->s_mds >= mdsc->max_sessions ||
 428             mdsc->sessions[s->s_mds] != s)
 429                 return -ENOENT;
 430         return 0;
 431 }
 432
 433 /*
 434  * create+register a new session for given mds.
 435  * called under mdsc->mutex.
 436  */
 437 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 438                                                  int mds)
 439 {
 440         struct ceph_mds_session *s;
 441
 442         if (mds >= mdsc->mdsmap->m_max_mds)
 443                 return ERR_PTR(-EINVAL);
 444
 445         s = kzalloc(sizeof(*s), GFP_NOFS);
 446         if (!s)
 447                 return ERR_PTR(-ENOMEM);
 448         s->s_mdsc = mdsc;
 449         s->s_mds = mds;
 450         s->s_state = CEPH_MDS_SESSION_NEW;
 451         s->s_ttl = 0;
 452         s->s_seq = 0;
 453         mutex_init(&s->s_mutex);
 454
 455         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 456
 457         spin_lock_init(&s->s_gen_ttl_lock);
 458         s->s_cap_gen = 0;
 459         s->s_cap_ttl = jiffies - 1;
 460
 461         spin_lock_init(&s->s_cap_lock);
 462         s->s_renew_requested = 0;
 463         s->s_renew_seq = 0;
 464         INIT_LIST_HEAD(&s->s_caps);
 465         s->s_nr_caps = 0;
 466         s->s_trim_caps = 0;
 467         atomic_set(&s->s_ref, 1);
 468         INIT_LIST_HEAD(&s->s_waiting);
 469         INIT_LIST_HEAD(&s->s_unsafe);
 470         s->s_num_cap_releases = 0;
 471         s->s_cap_reconnect = 0;
 472         s->s_cap_iterator = NULL;
 473         INIT_LIST_HEAD(&s->s_cap_releases);
 474         INIT_LIST_HEAD(&s->s_cap_flushing);
 475         INIT_LIST_HEAD(&s->s_cap_snaps_flushing);
 476
 477         dout("register_session mds%d\n", mds);
 478         if (mds >= mdsc->max_sessions) {
 479                 int newmax = 1 << get_count_order(mds+1);
 480                 struct ceph_mds_session **sa;
 481
 482                 dout("register_session realloc to %d\n", newmax);
 483                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 484                 if (sa == NULL)
 485                         goto fail_realloc;
 486                 if (mdsc->sessions) {
 487                         memcpy(sa, mdsc->sessions,
 488                                mdsc->max_sessions * sizeof(void *));
 489                         kfree(mdsc->sessions);
 490                 }
 491                 mdsc->sessions = sa;
 492                 mdsc->max_sessions = newmax;
 493         }
 494         mdsc->sessions[mds] = s;
 495         atomic_inc(&mdsc->num_sessions);
 496         atomic_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 497
 498         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 499                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 500
 501         return s;
 502
 503 fail_realloc:
 504         kfree(s);
 505         return ERR_PTR(-ENOMEM);
 506 }
 507
 508 /*
 509  * called under mdsc->mutex
 510  */
 511 static void __unregister_session(struct ceph_mds_client *mdsc,
 512                                struct ceph_mds_session *s)
 513 {
 514         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 515         BUG_ON(mdsc->sessions[s->s_mds] != s);
 516         mdsc->sessions[s->s_mds] = NULL;
 517         ceph_con_close(&s->s_con);
 518         ceph_put_mds_session(s);
 519         atomic_dec(&mdsc->num_sessions);
 520 }
 521
 522 /*
 523  * drop session refs in request.
 524  *
 525  * should be last request ref, or hold mdsc->mutex
 526  */
 527 static void put_request_session(struct ceph_mds_request *req)
 528 {
 529         if (req->r_session) {
 530                 ceph_put_mds_session(req->r_session);
 531                 req->r_session = NULL;
 532         }
 533 }
 534
 535 void ceph_mdsc_release_request(struct kref *kref)
 536 {
 537         struct ceph_mds_request *req = container_of(kref,
 538                                                     struct ceph_mds_request,
 539                                                     r_kref);
 540         destroy_reply_info(&req->r_reply_info);
 541         if (req->r_request)
 542                 ceph_msg_put(req->r_request);
 543         if (req->r_reply)
 544                 ceph_msg_put(req->r_reply);
 545         if (req->r_inode) {
 546                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 547                 iput(req->r_inode);
 548         }
 549         if (req->r_locked_dir)
 550                 ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
 551         iput(req->r_target_inode);
 552         if (req->r_dentry)
 553                 dput(req->r_dentry);
 554         if (req->r_old_dentry)
 555                 dput(req->r_old_dentry);
 556         if (req->r_old_dentry_dir) {
 557                 /*
 558                  * track (and drop pins for) r_old_dentry_dir
 559                  * separately, since r_old_dentry's d_parent may have
 560                  * changed between the dir mutex being dropped and
 561                  * this request being freed.
 562                  */
 563                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 564                                   CEPH_CAP_PIN);
 565                 iput(req->r_old_dentry_dir);
 566         }
 567         kfree(req->r_path1);
 568         kfree(req->r_path2);
 569         if (req->r_pagelist)
 570                 ceph_pagelist_release(req->r_pagelist);
 571         put_request_session(req);
 572         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 573         kfree(req);
 574 }
 575
 576 DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 577
 578 /*
 579  * lookup session, bump ref if found.
 580  *
 581  * called under mdsc->mutex.
 582  */
 583 static struct ceph_mds_request *
 584 lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 585 {
 586         struct ceph_mds_request *req;
 587
 588         req = lookup_request(&mdsc->request_tree, tid);
 589         if (req)
 590                 ceph_mdsc_get_request(req);
 591
 592         return req;
 593 }
 594
 595 /*
 596  * Register an in-flight request, and assign a tid.  Link to directory
 597  * are modifying (if any).
 598  *
 599  * Called under mdsc->mutex.
 600  */
 601 static void __register_request(struct ceph_mds_client *mdsc,
 602                                struct ceph_mds_request *req,
 603                                struct inode *dir)
 604 {
 605         req->r_tid = ++mdsc->last_tid;
 606         if (req->r_num_caps)
 607                 ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 608                                   req->r_num_caps);
 609         dout("__register_request %p tid %lld\n", req, req->r_tid);
 610         ceph_mdsc_get_request(req);
 611         insert_request(&mdsc->request_tree, req);
 612
 613         req->r_uid = current_fsuid();
 614         req->r_gid = current_fsgid();
 615
 616         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 617                 mdsc->oldest_tid = req->r_tid;
 618
 619         if (dir) {
 620                 ihold(dir);
 621                 req->r_unsafe_dir = dir;
 622         }
 623 }
 624
 625 static void __unregister_request(struct ceph_mds_client *mdsc,
 626                                  struct ceph_mds_request *req)
 627 {
 628         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 629
 630         if (req->r_tid == mdsc->oldest_tid) {
 631                 struct rb_node *p = rb_next(&req->r_node);
 632                 mdsc->oldest_tid = 0;
 633                 while (p) {
 634                         struct ceph_mds_request *next_req =
 635                                 rb_entry(p, struct ceph_mds_request, r_node);
 636                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 637                                 mdsc->oldest_tid = next_req->r_tid;
 638                                 break;
 639                         }
 640                         p = rb_next(p);
 641                 }
 642         }
 643
 644         erase_request(&mdsc->request_tree, req);
 645
 646         if (req->r_unsafe_dir && req->r_got_unsafe) {
 647                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 648                 spin_lock(&ci->i_unsafe_lock);
 649                 list_del_init(&req->r_unsafe_dir_item);
 650                 spin_unlock(&ci->i_unsafe_lock);
 651         }
 652         if (req->r_target_inode && req->r_got_unsafe) {
 653                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 654                 spin_lock(&ci->i_unsafe_lock);
 655                 list_del_init(&req->r_unsafe_target_item);
 656                 spin_unlock(&ci->i_unsafe_lock);
 657         }
 658
 659         if (req->r_unsafe_dir) {
 660                 iput(req->r_unsafe_dir);
 661                 req->r_unsafe_dir = NULL;
 662         }
 663
 664         complete_all(&req->r_safe_completion);
 665
 666         ceph_mdsc_put_request(req);
 667 }
 668
 669 /*
 670  * Choose mds to send request to next.  If there is a hint set in the
 671  * request (e.g., due to a prior forward hint from the mds), use that.
 672  * Otherwise, consult frag tree and/or caps to identify the
 673  * appropriate mds.  If all else fails, choose randomly.
 674  *
 675  * Called under mdsc->mutex.
 676  */
 677 static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 678 {
 679         /*
 680          * we don't need to worry about protecting the d_parent access
 681          * here because we never renaming inside the snapped namespace
 682          * except to resplice to another snapdir, and either the old or new
 683          * result is a valid result.
 684          */
 685         while (!IS_ROOT(dentry) && ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
 686                 dentry = dentry->d_parent;
 687         return dentry;
 688 }
 689
 690 static int __choose_mds(struct ceph_mds_client *mdsc,
 691                         struct ceph_mds_request *req)
 692 {
 693         struct inode *inode;
 694         struct ceph_inode_info *ci;
 695         struct ceph_cap *cap;
 696         int mode = req->r_direct_mode;
 697         int mds = -1;
 698         u32 hash = req->r_direct_hash;
 699         bool is_hash = req->r_direct_is_hash;
 700
 701         /*
 702          * is there a specific mds we should try?  ignore hint if we have
 703          * no session and the mds is not up (active or recovering).
 704          */
 705         if (req->r_resend_mds >= 0 &&
 706             (__have_session(mdsc, req->r_resend_mds) ||
 707              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 708                 dout("choose_mds using resend_mds mds%d\n",
 709                      req->r_resend_mds);
 710                 return req->r_resend_mds;
 711         }
 712
 713         if (mode == USE_RANDOM_MDS)
 714                 goto random;
 715
 716         inode = NULL;
 717         if (req->r_inode) {
 718                 inode = req->r_inode;
 719         } else if (req->r_dentry) {
 720                 /* ignore race with rename; old or new d_parent is okay */
 721                 struct dentry *parent = req->r_dentry->d_parent;
 722                 struct inode *dir = d_inode(parent);
 723
 724                 if (dir->i_sb != mdsc->fsc->sb) {
 725                         /* not this fs! */
 726                         inode = d_inode(req->r_dentry);
 727                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 728                         /* direct snapped/virtual snapdir requests
 729                          * based on parent dir inode */
 730                         struct dentry *dn = get_nonsnap_parent(parent);
 731                         inode = d_inode(dn);
 732                         dout("__choose_mds using nonsnap parent %p\n", inode);
 733                 } else {
 734                         /* dentry target */
 735                         inode = d_inode(req->r_dentry);
 736                         if (!inode || mode == USE_AUTH_MDS) {
 737                                 /* dir + name */
 738                                 inode = dir;
 739                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 740                                 is_hash = true;
 741                         }
 742                 }
 743         }
 744
 745         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 746              (int)hash, mode);
 747         if (!inode)
 748                 goto random;
 749         ci = ceph_inode(inode);
 750
 751         if (is_hash && S_ISDIR(inode->i_mode)) {
 752                 struct ceph_inode_frag frag;
 753                 int found;
 754
 755                 ceph_choose_frag(ci, hash, &frag, &found);
 756                 if (found) {
 757                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 758                                 u8 r;
 759
 760                                 /* choose a random replica */
 761                                 get_random_bytes(&r, 1);
 762                                 r %= frag.ndist;
 763                                 mds = frag.dist[r];
 764                                 dout("choose_mds %p %llx.%llx "
 765                                      "frag %u mds%d (%d/%d)\n",
 766                                      inode, ceph_vinop(inode),
 767                                      frag.frag, mds,
 768                                      (int)r, frag.ndist);
 769                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 770                                     CEPH_MDS_STATE_ACTIVE)
 771                                         return mds;
 772                         }
 773
 774                         /* since this file/dir wasn't known to be
 775                          * replicated, then we want to look for the
 776                          * authoritative mds. */
 777                         mode = USE_AUTH_MDS;
 778                         if (frag.mds >= 0) {
 779                                 /* choose auth mds */
 780                                 mds = frag.mds;
 781                                 dout("choose_mds %p %llx.%llx "
 782                                      "frag %u mds%d (auth)\n",
 783                                      inode, ceph_vinop(inode), frag.frag, mds);
 784                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 785                                     CEPH_MDS_STATE_ACTIVE)
 786                                         return mds;
 787                         }
 788                 }
 789         }
 790
 791         spin_lock(&ci->i_ceph_lock);
 792         cap = NULL;
 793         if (mode == USE_AUTH_MDS)
 794                 cap = ci->i_auth_cap;
 795         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 796                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 797         if (!cap) {
 798                 spin_unlock(&ci->i_ceph_lock);
 799                 goto random;
 800         }
 801         mds = cap->session->s_mds;
 802         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 803              inode, ceph_vinop(inode), mds,
 804              cap == ci->i_auth_cap ? "auth " : "", cap);
 805         spin_unlock(&ci->i_ceph_lock);
 806         return mds;
 807
 808 random:
 809         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 810         dout("choose_mds chose random mds%d\n", mds);
 811         return mds;
 812 }
 813
 814
 815 /*
 816  * session messages
 817  */
 818 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 819 {
 820         struct ceph_msg *msg;
 821         struct ceph_mds_session_head *h;
 822
 823         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 824                            false);
 825         if (!msg) {
 826                 pr_err("create_session_msg ENOMEM creating msg\n");
 827                 return NULL;
 828         }
 829         h = msg->front.iov_base;
 830         h->op = cpu_to_le32(op);
 831         h->seq = cpu_to_le64(seq);
 832
 833         return msg;
 834 }
 835
 836 /*
 837  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
 838  * to include additional client metadata fields.
 839  */
 840 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
 841 {
 842         struct ceph_msg *msg;
 843         struct ceph_mds_session_head *h;
 844         int i = -1;
 845         int metadata_bytes = 0;
 846         int metadata_key_count = 0;
 847         struct ceph_options *opt = mdsc->fsc->client->options;
 848         struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
 849         void *p;
 850
 851         const char* metadata[][2] = {
 852                 {"hostname", utsname()->nodename},
 853                 {"kernel_version", utsname()->release},
 854                 {"entity_id", opt->name ? : ""},
 855                 {"root", fsopt->server_path ? : "/"},
 856                 {NULL, NULL}
 857         };
 858
 859         /* Calculate serialized length of metadata */
 860         metadata_bytes = 4;  /* map length */
 861         for (i = 0; metadata[i][0] != NULL; ++i) {
 862                 metadata_bytes += 8 + strlen(metadata[i][0]) +
 863                         strlen(metadata[i][1]);
 864                 metadata_key_count++;
 865         }
 866
 867         /* Allocate the message */
 868         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + metadata_bytes,
 869                            GFP_NOFS, false);
 870         if (!msg) {
 871                 pr_err("create_session_msg ENOMEM creating msg\n");
 872                 return NULL;
 873         }
 874         h = msg->front.iov_base;
 875         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 876         h->seq = cpu_to_le64(seq);
 877
 878         /*
 879          * Serialize client metadata into waiting buffer space, using
 880          * the format that userspace expects for map<string, string>
 881          *
 882          * ClientSession messages with metadata are v2
 883          */
 884         msg->hdr.version = cpu_to_le16(2);
 885         msg->hdr.compat_version = cpu_to_le16(1);
 886
 887         /* The write pointer, following the session_head structure */
 888         p = msg->front.iov_base + sizeof(*h);
 889
 890         /* Number of entries in the map */
 891         ceph_encode_32(&p, metadata_key_count);
 892
 893         /* Two length-prefixed strings for each entry in the map */
 894         for (i = 0; metadata[i][0] != NULL; ++i) {
 895                 size_t const key_len = strlen(metadata[i][0]);
 896                 size_t const val_len = strlen(metadata[i][1]);
 897
 898                 ceph_encode_32(&p, key_len);
 899                 memcpy(p, metadata[i][0], key_len);
 900                 p += key_len;
 901                 ceph_encode_32(&p, val_len);
 902                 memcpy(p, metadata[i][1], val_len);
 903                 p += val_len;
 904         }
 905
 906         return msg;
 907 }
 908
 909 /*
 910  * send session open request.
 911  *
 912  * called under mdsc->mutex
 913  */
 914 static int __open_session(struct ceph_mds_client *mdsc,
 915                           struct ceph_mds_session *session)
 916 {
 917         struct ceph_msg *msg;
 918         int mstate;
 919         int mds = session->s_mds;
 920
 921         /* wait for mds to go active? */
 922         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 923         dout("open_session to mds%d (%s)\n", mds,
 924              ceph_mds_state_name(mstate));
 925         session->s_state = CEPH_MDS_SESSION_OPENING;
 926         session->s_renew_requested = jiffies;
 927
 928         /* send connect message */
 929         msg = create_session_open_msg(mdsc, session->s_seq);
 930         if (!msg)
 931                 return -ENOMEM;
 932         ceph_con_send(&session->s_con, msg);
 933         return 0;
 934 }
 935
 936 /*
 937  * open sessions for any export targets for the given mds
 938  *
 939  * called under mdsc->mutex
 940  */
 941 static struct ceph_mds_session *
 942 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
 943 {
 944         struct ceph_mds_session *session;
 945
 946         session = __ceph_lookup_mds_session(mdsc, target);
 947         if (!session) {
 948                 session = register_session(mdsc, target);
 949                 if (IS_ERR(session))
 950                         return session;
 951         }
 952         if (session->s_state == CEPH_MDS_SESSION_NEW ||
 953             session->s_state == CEPH_MDS_SESSION_CLOSING)
 954                 __open_session(mdsc, session);
 955
 956         return session;
 957 }
 958
 959 struct ceph_mds_session *
 960 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
 961 {
 962         struct ceph_mds_session *session;
 963
 964         dout("open_export_target_session to mds%d\n", target);
 965
 966         mutex_lock(&mdsc->mutex);
 967         session = __open_export_target_session(mdsc, target);
 968         mutex_unlock(&mdsc->mutex);
 969
 970         return session;
 971 }
 972
 973 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 974                                           struct ceph_mds_session *session)
 975 {
 976         struct ceph_mds_info *mi;
 977         struct ceph_mds_session *ts;
 978         int i, mds = session->s_mds;
 979
 980         if (mds >= mdsc->mdsmap->m_max_mds)
 981                 return;
 982
 983         mi = &mdsc->mdsmap->m_info[mds];
 984         dout("open_export_target_sessions for mds%d (%d targets)\n",
 985              session->s_mds, mi->num_export_targets);
 986
 987         for (i = 0; i < mi->num_export_targets; i++) {
 988                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
 989                 if (!IS_ERR(ts))
 990                         ceph_put_mds_session(ts);
 991         }
 992 }
 993
 994 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 995                                            struct ceph_mds_session *session)
 996 {
 997         mutex_lock(&mdsc->mutex);
 998         __open_export_target_sessions(mdsc, session);
 999         mutex_unlock(&mdsc->mutex);
1000 }
1001
1002 /*
1003  * session caps
1004  */
1005
1006 /* caller holds s_cap_lock, we drop it */
1007 static void cleanup_cap_releases(struct ceph_mds_client *mdsc,
1008                                  struct ceph_mds_session *session)
1009         __releases(session->s_cap_lock)
1010 {
1011         LIST_HEAD(tmp_list);
1012         list_splice_init(&session->s_cap_releases, &tmp_list);
1013         session->s_num_cap_releases = 0;
1014         spin_unlock(&session->s_cap_lock);
1015
1016         dout("cleanup_cap_releases mds%d\n", session->s_mds);
1017         while (!list_empty(&tmp_list)) {
1018                 struct ceph_cap *cap;
1019                 /* zero out the in-progress message */
1020                 cap = list_first_entry(&tmp_list,
1021                                         struct ceph_cap, session_caps);
1022                 list_del(&cap->session_caps);
1023                 ceph_put_cap(mdsc, cap);
1024         }
1025 }
1026
1027 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1028                                      struct ceph_mds_session *session)
1029 {
1030         struct ceph_mds_request *req;
1031         struct rb_node *p;
1032
1033         dout("cleanup_session_requests mds%d\n", session->s_mds);
1034         mutex_lock(&mdsc->mutex);
1035         while (!list_empty(&session->s_unsafe)) {
1036                 req = list_first_entry(&session->s_unsafe,
1037                                        struct ceph_mds_request, r_unsafe_item);
1038                 list_del_init(&req->r_unsafe_item);
1039                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1040                                     req->r_tid);
1041                 __unregister_request(mdsc, req);
1042         }
1043         /* zero r_attempts, so kick_requests() will re-send requests */
1044         p = rb_first(&mdsc->request_tree);
1045         while (p) {
1046                 req = rb_entry(p, struct ceph_mds_request, r_node);
1047                 p = rb_next(p);
1048                 if (req->r_session &&
1049                     req->r_session->s_mds == session->s_mds)
1050                         req->r_attempts = 0;
1051         }
1052         mutex_unlock(&mdsc->mutex);
1053 }
1054
1055 /*
1056  * Helper to safely iterate over all caps associated with a session, with
1057  * special care taken to handle a racing __ceph_remove_cap().
1058  *
1059  * Caller must hold session s_mutex.
1060  */
1061 static int iterate_session_caps(struct ceph_mds_session *session,
1062                                  int (*cb)(struct inode *, struct ceph_cap *,
1063                                             void *), void *arg)
1064 {
1065         struct list_head *p;
1066         struct ceph_cap *cap;
1067         struct inode *inode, *last_inode = NULL;
1068         struct ceph_cap *old_cap = NULL;
1069         int ret;
1070
1071         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1072         spin_lock(&session->s_cap_lock);
1073         p = session->s_caps.next;
1074         while (p != &session->s_caps) {
1075                 cap = list_entry(p, struct ceph_cap, session_caps);
1076                 inode = igrab(&cap->ci->vfs_inode);
1077                 if (!inode) {
1078                         p = p->next;
1079                         continue;
1080                 }
1081                 session->s_cap_iterator = cap;
1082                 spin_unlock(&session->s_cap_lock);
1083
1084                 if (last_inode) {
1085                         iput(last_inode);
1086                         last_inode = NULL;
1087                 }
1088                 if (old_cap) {
1089                         ceph_put_cap(session->s_mdsc, old_cap);
1090                         old_cap = NULL;
1091                 }
1092
1093                 ret = cb(inode, cap, arg);
1094                 last_inode = inode;
1095
1096                 spin_lock(&session->s_cap_lock);
1097                 p = p->next;
1098                 if (cap->ci == NULL) {
1099                         dout("iterate_session_caps  finishing cap %p removal\n",
1100                              cap);
1101                         BUG_ON(cap->session != session);
1102                         cap->session = NULL;
1103                         list_del_init(&cap->session_caps);
1104                         session->s_nr_caps--;
1105                         if (cap->queue_release) {
1106                                 list_add_tail(&cap->session_caps,
1107                                               &session->s_cap_releases);
1108                                 session->s_num_cap_releases++;
1109                         } else {
1110                                 old_cap = cap;  /* put_cap it w/o locks held */
1111                         }
1112                 }
1113                 if (ret < 0)
1114                         goto out;
1115         }
1116         ret = 0;
1117 out:
1118         session->s_cap_iterator = NULL;
1119         spin_unlock(&session->s_cap_lock);
1120
1121         iput(last_inode);
1122         if (old_cap)
1123                 ceph_put_cap(session->s_mdsc, old_cap);
1124
1125         return ret;
1126 }
1127
1128 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1129                                   void *arg)
1130 {
1131         struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1132         struct ceph_inode_info *ci = ceph_inode(inode);
1133         LIST_HEAD(to_remove);
1134         bool drop = false;
1135         bool invalidate = false;
1136
1137         dout("removing cap %p, ci is %p, inode is %p\n",
1138              cap, ci, &ci->vfs_inode);
1139         spin_lock(&ci->i_ceph_lock);
1140         __ceph_remove_cap(cap, false);
1141         if (!ci->i_auth_cap) {
1142                 struct ceph_cap_flush *cf;
1143                 struct ceph_mds_client *mdsc = fsc->mdsc;
1144
1145                 ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1146
1147                 if (ci->i_wrbuffer_ref > 0 &&
1148                     ACCESS_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
1149                         invalidate = true;
1150
1151                 while (true) {
1152                         struct rb_node *n = rb_first(&ci->i_cap_flush_tree);
1153                         if (!n)
1154                                 break;
1155                         cf = rb_entry(n, struct ceph_cap_flush, i_node);
1156                         rb_erase(&cf->i_node, &ci->i_cap_flush_tree);
1157                         list_add(&cf->list, &to_remove);
1158                 }
1159
1160                 spin_lock(&mdsc->cap_dirty_lock);
1161
1162                 list_for_each_entry(cf, &to_remove, list)
1163                         rb_erase(&cf->g_node, &mdsc->cap_flush_tree);
1164
1165                 if (!list_empty(&ci->i_dirty_item)) {
1166                         pr_warn_ratelimited(
1167                                 " dropping dirty %s state for %p %lld\n",
1168                                 ceph_cap_string(ci->i_dirty_caps),
1169                                 inode, ceph_ino(inode));
1170                         ci->i_dirty_caps = 0;
1171                         list_del_init(&ci->i_dirty_item);
1172                         drop = true;
1173                 }
1174                 if (!list_empty(&ci->i_flushing_item)) {
1175                         pr_warn_ratelimited(
1176                                 " dropping dirty+flushing %s state for %p %lld\n",
1177                                 ceph_cap_string(ci->i_flushing_caps),
1178                                 inode, ceph_ino(inode));
1179                         ci->i_flushing_caps = 0;
1180                         list_del_init(&ci->i_flushing_item);
1181                         mdsc->num_cap_flushing--;
1182                         drop = true;
1183                 }
1184                 spin_unlock(&mdsc->cap_dirty_lock);
1185
1186                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1187                         list_add(&ci->i_prealloc_cap_flush->list, &to_remove);
1188                         ci->i_prealloc_cap_flush = NULL;
1189                 }
1190         }
1191         spin_unlock(&ci->i_ceph_lock);
1192         while (!list_empty(&to_remove)) {
1193                 struct ceph_cap_flush *cf;
1194                 cf = list_first_entry(&to_remove,
1195                                       struct ceph_cap_flush, list);
1196                 list_del(&cf->list);
1197                 ceph_free_cap_flush(cf);
1198         }
1199
1200         wake_up_all(&ci->i_cap_wq);
1201         if (invalidate)
1202                 ceph_queue_invalidate(inode);
1203         if (drop)
1204                 iput(inode);
1205         return 0;
1206 }
1207
1208 /*
1209  * caller must hold session s_mutex
1210  */
1211 static void remove_session_caps(struct ceph_mds_session *session)
1212 {
1213         struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1214         struct super_block *sb = fsc->sb;
1215         dout("remove_session_caps on %p\n", session);
1216         iterate_session_caps(session, remove_session_caps_cb, fsc);
1217
1218         spin_lock(&session->s_cap_lock);
1219         if (session->s_nr_caps > 0) {
1220                 struct inode *inode;
1221                 struct ceph_cap *cap, *prev = NULL;
1222                 struct ceph_vino vino;
1223                 /*
1224                  * iterate_session_caps() skips inodes that are being
1225                  * deleted, we need to wait until deletions are complete.
1226                  * __wait_on_freeing_inode() is designed for the job,
1227                  * but it is not exported, so use lookup inode function
1228                  * to access it.
1229                  */
1230                 while (!list_empty(&session->s_caps)) {
1231                         cap = list_entry(session->s_caps.next,
1232                                          struct ceph_cap, session_caps);
1233                         if (cap == prev)
1234                                 break;
1235                         prev = cap;
1236                         vino = cap->ci->i_vino;
1237                         spin_unlock(&session->s_cap_lock);
1238
1239                         inode = ceph_find_inode(sb, vino);
1240                         iput(inode);
1241
1242                         spin_lock(&session->s_cap_lock);
1243                 }
1244         }
1245
1246         // drop cap expires and unlock s_cap_lock
1247         cleanup_cap_releases(session->s_mdsc, session);
1248
1249         BUG_ON(session->s_nr_caps > 0);
1250         BUG_ON(!list_empty(&session->s_cap_flushing));
1251 }
1252
1253 /*
1254  * wake up any threads waiting on this session's caps.  if the cap is
1255  * old (didn't get renewed on the client reconnect), remove it now.
1256  *
1257  * caller must hold s_mutex.
1258  */
1259 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1260                               void *arg)
1261 {
1262         struct ceph_inode_info *ci = ceph_inode(inode);
1263
1264         if (arg) {
1265                 spin_lock(&ci->i_ceph_lock);
1266                 ci->i_wanted_max_size = 0;
1267                 ci->i_requested_max_size = 0;
1268                 spin_unlock(&ci->i_ceph_lock);
1269         }
1270         wake_up_all(&ci->i_cap_wq);
1271         return 0;
1272 }
1273
1274 static void wake_up_session_caps(struct ceph_mds_session *session,
1275                                  int reconnect)
1276 {
1277         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1278         iterate_session_caps(session, wake_up_session_cb,
1279                              (void *)(unsigned long)reconnect);
1280 }
1281
1282 /*
1283  * Send periodic message to MDS renewing all currently held caps.  The
1284  * ack will reset the expiration for all caps from this session.
1285  *
1286  * caller holds s_mutex
1287  */
1288 static int send_renew_caps(struct ceph_mds_client *mdsc,
1289                            struct ceph_mds_session *session)
1290 {
1291         struct ceph_msg *msg;
1292         int state;
1293
1294         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1295             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1296                 pr_info("mds%d caps stale\n", session->s_mds);
1297         session->s_renew_requested = jiffies;
1298
1299         /* do not try to renew caps until a recovering mds has reconnected
1300          * with its clients. */
1301         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1302         if (state < CEPH_MDS_STATE_RECONNECT) {
1303                 dout("send_renew_caps ignoring mds%d (%s)\n",
1304                      session->s_mds, ceph_mds_state_name(state));
1305                 return 0;
1306         }
1307
1308         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1309                 ceph_mds_state_name(state));
1310         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1311                                  ++session->s_renew_seq);
1312         if (!msg)
1313                 return -ENOMEM;
1314         ceph_con_send(&session->s_con, msg);
1315         return 0;
1316 }
1317
1318 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1319                              struct ceph_mds_session *session, u64 seq)
1320 {
1321         struct ceph_msg *msg;
1322
1323         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1324              session->s_mds, ceph_session_state_name(session->s_state), seq);
1325         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1326         if (!msg)
1327                 return -ENOMEM;
1328         ceph_con_send(&session->s_con, msg);
1329         return 0;
1330 }
1331
1332
1333 /*
1334  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1335  *
1336  * Called under session->s_mutex
1337  */
1338 static void renewed_caps(struct ceph_mds_client *mdsc,
1339                          struct ceph_mds_session *session, int is_renew)
1340 {
1341         int was_stale;
1342         int wake = 0;
1343
1344         spin_lock(&session->s_cap_lock);
1345         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1346
1347         session->s_cap_ttl = session->s_renew_requested +
1348                 mdsc->mdsmap->m_session_timeout*HZ;
1349
1350         if (was_stale) {
1351                 if (time_before(jiffies, session->s_cap_ttl)) {
1352                         pr_info("mds%d caps renewed\n", session->s_mds);
1353                         wake = 1;
1354                 } else {
1355                         pr_info("mds%d caps still stale\n", session->s_mds);
1356                 }
1357         }
1358         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1359              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1360              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1361         spin_unlock(&session->s_cap_lock);
1362
1363         if (wake)
1364                 wake_up_session_caps(session, 0);
1365 }
1366
1367 /*
1368  * send a session close request
1369  */
1370 static int request_close_session(struct ceph_mds_client *mdsc,
1371                                  struct ceph_mds_session *session)
1372 {
1373         struct ceph_msg *msg;
1374
1375         dout("request_close_session mds%d state %s seq %lld\n",
1376              session->s_mds, ceph_session_state_name(session->s_state),
1377              session->s_seq);
1378         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1379         if (!msg)
1380                 return -ENOMEM;
1381         ceph_con_send(&session->s_con, msg);
1382         return 0;
1383 }
1384
1385 /*
1386  * Called with s_mutex held.
1387  */
1388 static int __close_session(struct ceph_mds_client *mdsc,
1389                          struct ceph_mds_session *session)
1390 {
1391         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1392                 return 0;
1393         session->s_state = CEPH_MDS_SESSION_CLOSING;
1394         return request_close_session(mdsc, session);
1395 }
1396
1397 /*
1398  * Trim old(er) caps.
1399  *
1400  * Because we can't cache an inode without one or more caps, we do
1401  * this indirectly: if a cap is unused, we prune its aliases, at which
1402  * point the inode will hopefully get dropped to.
1403  *
1404  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1405  * memory pressure from the MDS, though, so it needn't be perfect.
1406  */
1407 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1408 {
1409         struct ceph_mds_session *session = arg;
1410         struct ceph_inode_info *ci = ceph_inode(inode);
1411         int used, wanted, oissued, mine;
1412
1413         if (session->s_trim_caps <= 0)
1414                 return -1;
1415
1416         spin_lock(&ci->i_ceph_lock);
1417         mine = cap->issued | cap->implemented;
1418         used = __ceph_caps_used(ci);
1419         wanted = __ceph_caps_file_wanted(ci);
1420         oissued = __ceph_caps_issued_other(ci, cap);
1421
1422         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1423              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1424              ceph_cap_string(used), ceph_cap_string(wanted));
1425         if (cap == ci->i_auth_cap) {
1426                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1427                     !list_empty(&ci->i_cap_snaps))
1428                         goto out;
1429                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1430                         goto out;
1431         }
1432         /* The inode has cached pages, but it's no longer used.
1433          * we can safely drop it */
1434         if (wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1435             !(oissued & CEPH_CAP_FILE_CACHE)) {
1436           used = 0;
1437           oissued = 0;
1438         }
1439         if ((used | wanted) & ~oissued & mine)
1440                 goto out;   /* we need these caps */
1441
1442         session->s_trim_caps--;
1443         if (oissued) {
1444                 /* we aren't the only cap.. just remove us */
1445                 __ceph_remove_cap(cap, true);
1446         } else {
1447                 /* try dropping referring dentries */
1448                 spin_unlock(&ci->i_ceph_lock);
1449                 d_prune_aliases(inode);
1450                 dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1451                      inode, cap, atomic_read(&inode->i_count));
1452                 return 0;
1453         }
1454
1455 out:
1456         spin_unlock(&ci->i_ceph_lock);
1457         return 0;
1458 }
1459
1460 /*
1461  * Trim session cap count down to some max number.
1462  */
1463 static int trim_caps(struct ceph_mds_client *mdsc,
1464                      struct ceph_mds_session *session,
1465                      int max_caps)
1466 {
1467         int trim_caps = session->s_nr_caps - max_caps;
1468
1469         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1470              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1471         if (trim_caps > 0) {
1472                 session->s_trim_caps = trim_caps;
1473                 iterate_session_caps(session, trim_caps_cb, session);
1474                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1475                      session->s_mds, session->s_nr_caps, max_caps,
1476                         trim_caps - session->s_trim_caps);
1477                 session->s_trim_caps = 0;
1478         }
1479
1480         ceph_send_cap_releases(mdsc, session);
1481         return 0;
1482 }
1483
1484 static int check_capsnap_flush(struct ceph_inode_info *ci,
1485                                u64 want_snap_seq)
1486 {
1487         int ret = 1;
1488         spin_lock(&ci->i_ceph_lock);
1489         if (want_snap_seq > 0 && !list_empty(&ci->i_cap_snaps)) {
1490                 struct ceph_cap_snap *capsnap =
1491                         list_first_entry(&ci->i_cap_snaps,
1492                                          struct ceph_cap_snap, ci_item);
1493                 ret = capsnap->follows >= want_snap_seq;
1494         }
1495         spin_unlock(&ci->i_ceph_lock);
1496         return ret;
1497 }
1498
1499 static int check_caps_flush(struct ceph_mds_client *mdsc,
1500                             u64 want_flush_tid)
1501 {
1502         struct rb_node *n;
1503         struct ceph_cap_flush *cf;
1504         int ret = 1;
1505
1506         spin_lock(&mdsc->cap_dirty_lock);
1507         n = rb_first(&mdsc->cap_flush_tree);
1508         cf = n ? rb_entry(n, struct ceph_cap_flush, g_node) : NULL;
1509         if (cf && cf->tid <= want_flush_tid) {
1510                 dout("check_caps_flush still flushing tid %llu <= %llu\n",
1511                      cf->tid, want_flush_tid);
1512                 ret = 0;
1513         }
1514         spin_unlock(&mdsc->cap_dirty_lock);
1515         return ret;
1516 }
1517
1518 /*
1519  * flush all dirty inode data to disk.
1520  *
1521  * returns true if we've flushed through want_flush_tid
1522  */
1523 static void wait_caps_flush(struct ceph_mds_client *mdsc,
1524                             u64 want_flush_tid, u64 want_snap_seq)
1525 {
1526         int mds;
1527
1528         dout("check_caps_flush want %llu snap want %llu\n",
1529              want_flush_tid, want_snap_seq);
1530         mutex_lock(&mdsc->mutex);
1531         for (mds = 0; mds < mdsc->max_sessions; ) {
1532                 struct ceph_mds_session *session = mdsc->sessions[mds];
1533                 struct inode *inode = NULL;
1534
1535                 if (!session) {
1536                         mds++;
1537                         continue;
1538                 }
1539                 get_session(session);
1540                 mutex_unlock(&mdsc->mutex);
1541
1542                 mutex_lock(&session->s_mutex);
1543                 if (!list_empty(&session->s_cap_snaps_flushing)) {
1544                         struct ceph_cap_snap *capsnap =
1545                                 list_first_entry(&session->s_cap_snaps_flushing,
1546                                                  struct ceph_cap_snap,
1547                                                  flushing_item);
1548                         struct ceph_inode_info *ci = capsnap->ci;
1549                         if (!check_capsnap_flush(ci, want_snap_seq)) {
1550                                 dout("check_cap_flush still flushing snap %p "
1551                                      "follows %lld <= %lld to mds%d\n",
1552                                      &ci->vfs_inode, capsnap->follows,
1553                                      want_snap_seq, mds);
1554                                 inode = igrab(&ci->vfs_inode);
1555                         }
1556                 }
1557                 mutex_unlock(&session->s_mutex);
1558                 ceph_put_mds_session(session);
1559
1560                 if (inode) {
1561                         wait_event(mdsc->cap_flushing_wq,
1562                                    check_capsnap_flush(ceph_inode(inode),
1563                                                        want_snap_seq));
1564                         iput(inode);
1565                 } else {
1566                         mds++;
1567                 }
1568
1569                 mutex_lock(&mdsc->mutex);
1570         }
1571         mutex_unlock(&mdsc->mutex);
1572
1573         wait_event(mdsc->cap_flushing_wq,
1574                    check_caps_flush(mdsc, want_flush_tid));
1575
1576         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
1577 }
1578
1579 /*
1580  * called under s_mutex
1581  */
1582 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1583                             struct ceph_mds_session *session)
1584 {
1585         struct ceph_msg *msg = NULL;
1586         struct ceph_mds_cap_release *head;
1587         struct ceph_mds_cap_item *item;
1588         struct ceph_cap *cap;
1589         LIST_HEAD(tmp_list);
1590         int num_cap_releases;
1591
1592         spin_lock(&session->s_cap_lock);
1593 again:
1594         list_splice_init(&session->s_cap_releases, &tmp_list);
1595         num_cap_releases = session->s_num_cap_releases;
1596         session->s_num_cap_releases = 0;
1597         spin_unlock(&session->s_cap_lock);
1598
1599         while (!list_empty(&tmp_list)) {
1600                 if (!msg) {
1601                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1602                                         PAGE_SIZE, GFP_NOFS, false);
1603                         if (!msg)
1604                                 goto out_err;
1605                         head = msg->front.iov_base;
1606                         head->num = cpu_to_le32(0);
1607                         msg->front.iov_len = sizeof(*head);
1608                 }
1609                 cap = list_first_entry(&tmp_list, struct ceph_cap,
1610                                         session_caps);
1611                 list_del(&cap->session_caps);
1612                 num_cap_releases--;
1613
1614                 head = msg->front.iov_base;
1615                 le32_add_cpu(&head->num, 1);
1616                 item = msg->front.iov_base + msg->front.iov_len;
1617                 item->ino = cpu_to_le64(cap->cap_ino);
1618                 item->cap_id = cpu_to_le64(cap->cap_id);
1619                 item->migrate_seq = cpu_to_le32(cap->mseq);
1620                 item->seq = cpu_to_le32(cap->issue_seq);
1621                 msg->front.iov_len += sizeof(*item);
1622
1623                 ceph_put_cap(mdsc, cap);
1624
1625                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1626                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1627                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1628                         ceph_con_send(&session->s_con, msg);
1629                         msg = NULL;
1630                 }
1631         }
1632
1633         BUG_ON(num_cap_releases != 0);
1634
1635         spin_lock(&session->s_cap_lock);
1636         if (!list_empty(&session->s_cap_releases))
1637                 goto again;
1638         spin_unlock(&session->s_cap_lock);
1639
1640         if (msg) {
1641                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1642                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1643                 ceph_con_send(&session->s_con, msg);
1644         }
1645         return;
1646 out_err:
1647         pr_err("send_cap_releases mds%d, failed to allocate message\n",
1648                 session->s_mds);
1649         spin_lock(&session->s_cap_lock);
1650         list_splice(&tmp_list, &session->s_cap_releases);
1651         session->s_num_cap_releases += num_cap_releases;
1652         spin_unlock(&session->s_cap_lock);
1653 }
1654
1655 /*
1656  * requests
1657  */
1658
1659 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1660                                     struct inode *dir)
1661 {
1662         struct ceph_inode_info *ci = ceph_inode(dir);
1663         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1664         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1665         size_t size = sizeof(struct ceph_mds_reply_dir_entry);
1666         int order, num_entries;
1667
1668         spin_lock(&ci->i_ceph_lock);
1669         num_entries = ci->i_files + ci->i_subdirs;
1670         spin_unlock(&ci->i_ceph_lock);
1671         num_entries = max(num_entries, 1);
1672         num_entries = min(num_entries, opt->max_readdir);
1673
1674         order = get_order(size * num_entries);
1675         while (order >= 0) {
1676                 rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
1677                                                              __GFP_NOWARN,
1678                                                              order);
1679                 if (rinfo->dir_entries)
1680                         break;
1681                 order--;
1682         }
1683         if (!rinfo->dir_entries)
1684                 return -ENOMEM;
1685
1686         num_entries = (PAGE_SIZE << order) / size;
1687         num_entries = min(num_entries, opt->max_readdir);
1688
1689         rinfo->dir_buf_size = PAGE_SIZE << order;
1690         req->r_num_caps = num_entries + 1;
1691         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1692         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1693         return 0;
1694 }
1695
1696 /*
1697  * Create an mds request.
1698  */
1699 struct ceph_mds_request *
1700 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1701 {
1702         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1703
1704         if (!req)
1705                 return ERR_PTR(-ENOMEM);
1706
1707         mutex_init(&req->r_fill_mutex);
1708         req->r_mdsc = mdsc;
1709         req->r_started = jiffies;
1710         req->r_resend_mds = -1;
1711         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1712         INIT_LIST_HEAD(&req->r_unsafe_target_item);
1713         req->r_fmode = -1;
1714         kref_init(&req->r_kref);
1715         RB_CLEAR_NODE(&req->r_node);
1716         INIT_LIST_HEAD(&req->r_wait);
1717         init_completion(&req->r_completion);
1718         init_completion(&req->r_safe_completion);
1719         INIT_LIST_HEAD(&req->r_unsafe_item);
1720
1721         req->r_stamp = current_fs_time(mdsc->fsc->sb);
1722
1723         req->r_op = op;
1724         req->r_direct_mode = mode;
1725         return req;
1726 }
1727
1728 /*
1729  * return oldest (lowest) request, tid in request tree, 0 if none.
1730  *
1731  * called under mdsc->mutex.
1732  */
1733 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1734 {
1735         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1736                 return NULL;
1737         return rb_entry(rb_first(&mdsc->request_tree),
1738                         struct ceph_mds_request, r_node);
1739 }
1740
1741 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1742 {
1743         return mdsc->oldest_tid;
1744 }
1745
1746 /*
1747  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1748  * on build_path_from_dentry in fs/cifs/dir.c.
1749  *
1750  * If @stop_on_nosnap, generate path relative to the first non-snapped
1751  * inode.
1752  *
1753  * Encode hidden .snap dirs as a double /, i.e.
1754  *   foo/.snap/bar -> foo//bar
1755  */
1756 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1757                            int stop_on_nosnap)
1758 {
1759         struct dentry *temp;
1760         char *path;
1761         int len, pos;
1762         unsigned seq;
1763
1764         if (dentry == NULL)
1765                 return ERR_PTR(-EINVAL);
1766
1767 retry:
1768         len = 0;
1769         seq = read_seqbegin(&rename_lock);
1770         rcu_read_lock();
1771         for (temp = dentry; !IS_ROOT(temp);) {
1772                 struct inode *inode = d_inode(temp);
1773                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1774                         len++;  /* slash only */
1775                 else if (stop_on_nosnap && inode &&
1776                          ceph_snap(inode) == CEPH_NOSNAP)
1777                         break;
1778                 else
1779                         len += 1 + temp->d_name.len;
1780                 temp = temp->d_parent;
1781         }
1782         rcu_read_unlock();
1783         if (len)
1784                 len--;  /* no leading '/' */
1785
1786         path = kmalloc(len+1, GFP_NOFS);
1787         if (path == NULL)
1788                 return ERR_PTR(-ENOMEM);
1789         pos = len;
1790         path[pos] = 0;  /* trailing null */
1791         rcu_read_lock();
1792         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1793                 struct inode *inode;
1794
1795                 spin_lock(&temp->d_lock);
1796                 inode = d_inode(temp);
1797                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1798                         dout("build_path path+%d: %p SNAPDIR\n",
1799                              pos, temp);
1800                 } else if (stop_on_nosnap && inode &&
1801                            ceph_snap(inode) == CEPH_NOSNAP) {
1802                         spin_unlock(&temp->d_lock);
1803                         break;
1804                 } else {
1805                         pos -= temp->d_name.len;
1806                         if (pos < 0) {
1807                                 spin_unlock(&temp->d_lock);
1808                                 break;
1809                         }
1810                         strncpy(path + pos, temp->d_name.name,
1811                                 temp->d_name.len);
1812                 }
1813                 spin_unlock(&temp->d_lock);
1814                 if (pos)
1815                         path[--pos] = '/';
1816                 temp = temp->d_parent;
1817         }
1818         rcu_read_unlock();
1819         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1820                 pr_err("build_path did not end path lookup where "
1821                        "expected, namelen is %d, pos is %d\n", len, pos);
1822                 /* presumably this is only possible if racing with a
1823                    rename of one of the parent directories (we can not
1824                    lock the dentries above us to prevent this, but
1825                    retrying should be harmless) */
1826                 kfree(path);
1827                 goto retry;
1828         }
1829
1830         *base = ceph_ino(d_inode(temp));
1831         *plen = len;
1832         dout("build_path on %p %d built %llx '%.*s'\n",
1833              dentry, d_count(dentry), *base, len, path);
1834         return path;
1835 }
1836
1837 static int build_dentry_path(struct dentry *dentry,
1838                              const char **ppath, int *ppathlen, u64 *pino,
1839                              int *pfreepath)
1840 {
1841         char *path;
1842
1843         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP) {
1844                 *pino = ceph_ino(d_inode(dentry->d_parent));
1845                 *ppath = dentry->d_name.name;
1846                 *ppathlen = dentry->d_name.len;
1847                 return 0;
1848         }
1849         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1850         if (IS_ERR(path))
1851                 return PTR_ERR(path);
1852         *ppath = path;
1853         *pfreepath = 1;
1854         return 0;
1855 }
1856
1857 static int build_inode_path(struct inode *inode,
1858                             const char **ppath, int *ppathlen, u64 *pino,
1859                             int *pfreepath)
1860 {
1861         struct dentry *dentry;
1862         char *path;
1863
1864         if (ceph_snap(inode) == CEPH_NOSNAP) {
1865                 *pino = ceph_ino(inode);
1866                 *ppathlen = 0;
1867                 return 0;
1868         }
1869         dentry = d_find_alias(inode);
1870         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1871         dput(dentry);
1872         if (IS_ERR(path))
1873                 return PTR_ERR(path);
1874         *ppath = path;
1875         *pfreepath = 1;
1876         return 0;
1877 }
1878
1879 /*
1880  * request arguments may be specified via an inode *, a dentry *, or
1881  * an explicit ino+path.
1882  */
1883 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1884                                   const char *rpath, u64 rino,
1885                                   const char **ppath, int *pathlen,
1886                                   u64 *ino, int *freepath)
1887 {
1888         int r = 0;
1889
1890         if (rinode) {
1891                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1892                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1893                      ceph_snap(rinode));
1894         } else if (rdentry) {
1895                 r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1896                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1897                      *ppath);
1898         } else if (rpath || rino) {
1899                 *ino = rino;
1900                 *ppath = rpath;
1901                 *pathlen = rpath ? strlen(rpath) : 0;
1902                 dout(" path %.*s\n", *pathlen, rpath);
1903         }
1904
1905         return r;
1906 }
1907
1908 /*
1909  * called under mdsc->mutex
1910  */
1911 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1912                                                struct ceph_mds_request *req,
1913                                                int mds, bool drop_cap_releases)
1914 {
1915         struct ceph_msg *msg;
1916         struct ceph_mds_request_head *head;
1917         const char *path1 = NULL;
1918         const char *path2 = NULL;
1919         u64 ino1 = 0, ino2 = 0;
1920         int pathlen1 = 0, pathlen2 = 0;
1921         int freepath1 = 0, freepath2 = 0;
1922         int len;
1923         u16 releases;
1924         void *p, *end;
1925         int ret;
1926
1927         ret = set_request_path_attr(req->r_inode, req->r_dentry,
1928                               req->r_path1, req->r_ino1.ino,
1929                               &path1, &pathlen1, &ino1, &freepath1);
1930         if (ret < 0) {
1931                 msg = ERR_PTR(ret);
1932                 goto out;
1933         }
1934
1935         ret = set_request_path_attr(NULL, req->r_old_dentry,
1936                               req->r_path2, req->r_ino2.ino,
1937                               &path2, &pathlen2, &ino2, &freepath2);
1938         if (ret < 0) {
1939                 msg = ERR_PTR(ret);
1940                 goto out_free1;
1941         }
1942
1943         len = sizeof(*head) +
1944                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1945                 sizeof(struct ceph_timespec);
1946
1947         /* calculate (max) length for cap releases */
1948         len += sizeof(struct ceph_mds_request_release) *
1949                 (!!req->r_inode_drop + !!req->r_dentry_drop +
1950                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1951         if (req->r_dentry_drop)
1952                 len += req->r_dentry->d_name.len;
1953         if (req->r_old_dentry_drop)
1954                 len += req->r_old_dentry->d_name.len;
1955
1956         msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1957         if (!msg) {
1958                 msg = ERR_PTR(-ENOMEM);
1959                 goto out_free2;
1960         }
1961
1962         msg->hdr.version = cpu_to_le16(2);
1963         msg->hdr.tid = cpu_to_le64(req->r_tid);
1964
1965         head = msg->front.iov_base;
1966         p = msg->front.iov_base + sizeof(*head);
1967         end = msg->front.iov_base + msg->front.iov_len;
1968
1969         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1970         head->op = cpu_to_le32(req->r_op);
1971         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1972         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1973         head->args = req->r_args;
1974
1975         ceph_encode_filepath(&p, end, ino1, path1);
1976         ceph_encode_filepath(&p, end, ino2, path2);
1977
1978         /* make note of release offset, in case we need to replay */
1979         req->r_request_release_offset = p - msg->front.iov_base;
1980
1981         /* cap releases */
1982         releases = 0;
1983         if (req->r_inode_drop)
1984                 releases += ceph_encode_inode_release(&p,
1985                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
1986                       mds, req->r_inode_drop, req->r_inode_unless, 0);
1987         if (req->r_dentry_drop)
1988                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
1989                        mds, req->r_dentry_drop, req->r_dentry_unless);
1990         if (req->r_old_dentry_drop)
1991                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1992                        mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1993         if (req->r_old_inode_drop)
1994                 releases += ceph_encode_inode_release(&p,
1995                       d_inode(req->r_old_dentry),
1996                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1997
1998         if (drop_cap_releases) {
1999                 releases = 0;
2000                 p = msg->front.iov_base + req->r_request_release_offset;
2001         }
2002
2003         head->num_releases = cpu_to_le16(releases);
2004
2005         /* time stamp */
2006         {
2007                 struct ceph_timespec ts;
2008                 ceph_encode_timespec(&ts, &req->r_stamp);
2009                 ceph_encode_copy(&p, &ts, sizeof(ts));
2010         }
2011
2012         BUG_ON(p > end);
2013         msg->front.iov_len = p - msg->front.iov_base;
2014         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2015
2016         if (req->r_pagelist) {
2017                 struct ceph_pagelist *pagelist = req->r_pagelist;
2018                 atomic_inc(&pagelist->refcnt);
2019                 ceph_msg_data_add_pagelist(msg, pagelist);
2020                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2021         } else {
2022                 msg->hdr.data_len = 0;
2023         }
2024
2025         msg->hdr.data_off = cpu_to_le16(0);
2026
2027 out_free2:
2028         if (freepath2)
2029                 kfree((char *)path2);
2030 out_free1:
2031         if (freepath1)
2032                 kfree((char *)path1);
2033 out:
2034         return msg;
2035 }
2036
2037 /*
2038  * called under mdsc->mutex if error, under no mutex if
2039  * success.
2040  */
2041 static void complete_request(struct ceph_mds_client *mdsc,
2042                              struct ceph_mds_request *req)
2043 {
2044         if (req->r_callback)
2045                 req->r_callback(mdsc, req);
2046         else
2047                 complete_all(&req->r_completion);
2048 }
2049
2050 /*
2051  * called under mdsc->mutex
2052  */
2053 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2054                                   struct ceph_mds_request *req,
2055                                   int mds, bool drop_cap_releases)
2056 {
2057         struct ceph_mds_request_head *rhead;
2058         struct ceph_msg *msg;
2059         int flags = 0;
2060
2061         req->r_attempts++;
2062         if (req->r_inode) {
2063                 struct ceph_cap *cap =
2064                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2065
2066                 if (cap)
2067                         req->r_sent_on_mseq = cap->mseq;
2068                 else
2069                         req->r_sent_on_mseq = -1;
2070         }
2071         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2072              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2073
2074         if (req->r_got_unsafe) {
2075                 void *p;
2076                 /*
2077                  * Replay.  Do not regenerate message (and rebuild
2078                  * paths, etc.); just use the original message.
2079                  * Rebuilding paths will break for renames because
2080                  * d_move mangles the src name.
2081                  */
2082                 msg = req->r_request;
2083                 rhead = msg->front.iov_base;
2084
2085                 flags = le32_to_cpu(rhead->flags);
2086                 flags |= CEPH_MDS_FLAG_REPLAY;
2087                 rhead->flags = cpu_to_le32(flags);
2088
2089                 if (req->r_target_inode)
2090                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2091
2092                 rhead->num_retry = req->r_attempts - 1;
2093
2094                 /* remove cap/dentry releases from message */
2095                 rhead->num_releases = 0;
2096
2097                 /* time stamp */
2098                 p = msg->front.iov_base + req->r_request_release_offset;
2099                 {
2100                         struct ceph_timespec ts;
2101                         ceph_encode_timespec(&ts, &req->r_stamp);
2102                         ceph_encode_copy(&p, &ts, sizeof(ts));
2103                 }
2104
2105                 msg->front.iov_len = p - msg->front.iov_base;
2106                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2107                 return 0;
2108         }
2109
2110         if (req->r_request) {
2111                 ceph_msg_put(req->r_request);
2112                 req->r_request = NULL;
2113         }
2114         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2115         if (IS_ERR(msg)) {
2116                 req->r_err = PTR_ERR(msg);
2117                 return PTR_ERR(msg);
2118         }
2119         req->r_request = msg;
2120
2121         rhead = msg->front.iov_base;
2122         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2123         if (req->r_got_unsafe)
2124                 flags |= CEPH_MDS_FLAG_REPLAY;
2125         if (req->r_locked_dir)
2126                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2127         rhead->flags = cpu_to_le32(flags);
2128         rhead->num_fwd = req->r_num_fwd;
2129         rhead->num_retry = req->r_attempts - 1;
2130         rhead->ino = 0;
2131
2132         dout(" r_locked_dir = %p\n", req->r_locked_dir);
2133         return 0;
2134 }
2135
2136 /*
2137  * send request, or put it on the appropriate wait list.
2138  */
2139 static int __do_request(struct ceph_mds_client *mdsc,
2140                         struct ceph_mds_request *req)
2141 {
2142         struct ceph_mds_session *session = NULL;
2143         int mds = -1;
2144         int err = 0;
2145
2146         if (req->r_err || req->r_got_result) {
2147                 if (req->r_aborted)
2148                         __unregister_request(mdsc, req);
2149                 goto out;
2150         }
2151
2152         if (req->r_timeout &&
2153             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2154                 dout("do_request timed out\n");
2155                 err = -EIO;
2156                 goto finish;
2157         }
2158         if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2159                 dout("do_request forced umount\n");
2160                 err = -EIO;
2161                 goto finish;
2162         }
2163
2164         put_request_session(req);
2165
2166         mds = __choose_mds(mdsc, req);
2167         if (mds < 0 ||
2168             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2169                 dout("do_request no mds or not active, waiting for map\n");
2170                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2171                 goto out;
2172         }
2173
2174         /* get, open session */
2175         session = __ceph_lookup_mds_session(mdsc, mds);
2176         if (!session) {
2177                 session = register_session(mdsc, mds);
2178                 if (IS_ERR(session)) {
2179                         err = PTR_ERR(session);
2180                         goto finish;
2181                 }
2182         }
2183         req->r_session = get_session(session);
2184
2185         dout("do_request mds%d session %p state %s\n", mds, session,
2186              ceph_session_state_name(session->s_state));
2187         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2188             session->s_state != CEPH_MDS_SESSION_HUNG) {
2189                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2190                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2191                         __open_session(mdsc, session);
2192                 list_add(&req->r_wait, &session->s_waiting);
2193                 goto out_session;
2194         }
2195
2196         /* send request */
2197         req->r_resend_mds = -1;   /* forget any previous mds hint */
2198
2199         if (req->r_request_started == 0)   /* note request start time */
2200                 req->r_request_started = jiffies;
2201
2202         err = __prepare_send_request(mdsc, req, mds, false);
2203         if (!err) {
2204                 ceph_msg_get(req->r_request);
2205                 ceph_con_send(&session->s_con, req->r_request);
2206         }
2207
2208 out_session:
2209         ceph_put_mds_session(session);
2210 finish:
2211         if (err) {
2212                 dout("__do_request early error %d\n", err);
2213                 req->r_err = err;
2214                 complete_request(mdsc, req);
2215                 __unregister_request(mdsc, req);
2216         }
2217 out:
2218         return err;
2219 }
2220
2221 /*
2222  * called under mdsc->mutex
2223  */
2224 static void __wake_requests(struct ceph_mds_client *mdsc,
2225                             struct list_head *head)
2226 {
2227         struct ceph_mds_request *req;
2228         LIST_HEAD(tmp_list);
2229
2230         list_splice_init(head, &tmp_list);
2231
2232         while (!list_empty(&tmp_list)) {
2233                 req = list_entry(tmp_list.next,
2234                                  struct ceph_mds_request, r_wait);
2235                 list_del_init(&req->r_wait);
2236                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2237                 __do_request(mdsc, req);
2238         }
2239 }
2240
2241 /*
2242  * Wake up threads with requests pending for @mds, so that they can
2243  * resubmit their requests to a possibly different mds.
2244  */
2245 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2246 {
2247         struct ceph_mds_request *req;
2248         struct rb_node *p = rb_first(&mdsc->request_tree);
2249
2250         dout("kick_requests mds%d\n", mds);
2251         while (p) {
2252                 req = rb_entry(p, struct ceph_mds_request, r_node);
2253                 p = rb_next(p);
2254                 if (req->r_got_unsafe)
2255                         continue;
2256                 if (req->r_attempts > 0)
2257                         continue; /* only new requests */
2258                 if (req->r_session &&
2259                     req->r_session->s_mds == mds) {
2260                         dout(" kicking tid %llu\n", req->r_tid);
2261                         list_del_init(&req->r_wait);
2262                         __do_request(mdsc, req);
2263                 }
2264         }
2265 }
2266
2267 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2268                               struct ceph_mds_request *req)
2269 {
2270         dout("submit_request on %p\n", req);
2271         mutex_lock(&mdsc->mutex);
2272         __register_request(mdsc, req, NULL);
2273         __do_request(mdsc, req);
2274         mutex_unlock(&mdsc->mutex);
2275 }
2276
2277 /*
2278  * Synchrously perform an mds request.  Take care of all of the
2279  * session setup, forwarding, retry details.
2280  */
2281 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2282                          struct inode *dir,
2283                          struct ceph_mds_request *req)
2284 {
2285         int err;
2286
2287         dout("do_request on %p\n", req);
2288
2289         /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2290         if (req->r_inode)
2291                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2292         if (req->r_locked_dir)
2293                 ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2294         if (req->r_old_dentry_dir)
2295                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2296                                   CEPH_CAP_PIN);
2297
2298         /* issue */
2299         mutex_lock(&mdsc->mutex);
2300         __register_request(mdsc, req, dir);
2301         __do_request(mdsc, req);
2302
2303         if (req->r_err) {
2304                 err = req->r_err;
2305                 goto out;
2306         }
2307
2308         /* wait */
2309         mutex_unlock(&mdsc->mutex);
2310         dout("do_request waiting\n");
2311         if (!req->r_timeout && req->r_wait_for_completion) {
2312                 err = req->r_wait_for_completion(mdsc, req);
2313         } else {
2314                 long timeleft = wait_for_completion_killable_timeout(
2315                                         &req->r_completion,
2316                                         ceph_timeout_jiffies(req->r_timeout));
2317                 if (timeleft > 0)
2318                         err = 0;
2319                 else if (!timeleft)
2320                         err = -EIO;  /* timed out */
2321                 else
2322                         err = timeleft;  /* killed */
2323         }
2324         dout("do_request waited, got %d\n", err);
2325         mutex_lock(&mdsc->mutex);
2326
2327         /* only abort if we didn't race with a real reply */
2328         if (req->r_got_result) {
2329                 err = le32_to_cpu(req->r_reply_info.head->result);
2330         } else if (err < 0) {
2331                 dout("aborted request %lld with %d\n", req->r_tid, err);
2332
2333                 /*
2334                  * ensure we aren't running concurrently with
2335                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2336                  * rely on locks (dir mutex) held by our caller.
2337                  */
2338                 mutex_lock(&req->r_fill_mutex);
2339                 req->r_err = err;
2340                 req->r_aborted = true;
2341                 mutex_unlock(&req->r_fill_mutex);
2342
2343                 if (req->r_locked_dir &&
2344                     (req->r_op & CEPH_MDS_OP_WRITE))
2345                         ceph_invalidate_dir_request(req);
2346         } else {
2347                 err = req->r_err;
2348         }
2349
2350 out:
2351         mutex_unlock(&mdsc->mutex);
2352         dout("do_request %p done, result %d\n", req, err);
2353         return err;
2354 }
2355
2356 /*
2357  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2358  * namespace request.
2359  */
2360 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2361 {
2362         struct inode *inode = req->r_locked_dir;
2363
2364         dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2365
2366         ceph_dir_clear_complete(inode);
2367         if (req->r_dentry)
2368                 ceph_invalidate_dentry_lease(req->r_dentry);
2369         if (req->r_old_dentry)
2370                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2371 }
2372
2373 /*
2374  * Handle mds reply.
2375  *
2376  * We take the session mutex and parse and process the reply immediately.
2377  * This preserves the logical ordering of replies, capabilities, etc., sent
2378  * by the MDS as they are applied to our local cache.
2379  */
2380 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2381 {
2382         struct ceph_mds_client *mdsc = session->s_mdsc;
2383         struct ceph_mds_request *req;
2384         struct ceph_mds_reply_head *head = msg->front.iov_base;
2385         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2386         struct ceph_snap_realm *realm;
2387         u64 tid;
2388         int err, result;
2389         int mds = session->s_mds;
2390
2391         if (msg->front.iov_len < sizeof(*head)) {
2392                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2393                 ceph_msg_dump(msg);
2394                 return;
2395         }
2396
2397         /* get request, session */
2398         tid = le64_to_cpu(msg->hdr.tid);
2399         mutex_lock(&mdsc->mutex);
2400         req = lookup_get_request(mdsc, tid);
2401         if (!req) {
2402                 dout("handle_reply on unknown tid %llu\n", tid);
2403                 mutex_unlock(&mdsc->mutex);
2404                 return;
2405         }
2406         dout("handle_reply %p\n", req);
2407
2408         /* correct session? */
2409         if (req->r_session != session) {
2410                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2411                        " not mds%d\n", tid, session->s_mds,
2412                        req->r_session ? req->r_session->s_mds : -1);
2413                 mutex_unlock(&mdsc->mutex);
2414                 goto out;
2415         }
2416
2417         /* dup? */
2418         if ((req->r_got_unsafe && !head->safe) ||
2419             (req->r_got_safe && head->safe)) {
2420                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2421                            head->safe ? "safe" : "unsafe", tid, mds);
2422                 mutex_unlock(&mdsc->mutex);
2423                 goto out;
2424         }
2425         if (req->r_got_safe) {
2426                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2427                            tid, mds);
2428                 mutex_unlock(&mdsc->mutex);
2429                 goto out;
2430         }
2431
2432         result = le32_to_cpu(head->result);
2433
2434         /*
2435          * Handle an ESTALE
2436          * if we're not talking to the authority, send to them
2437          * if the authority has changed while we weren't looking,
2438          * send to new authority
2439          * Otherwise we just have to return an ESTALE
2440          */
2441         if (result == -ESTALE) {
2442                 dout("got ESTALE on request %llu", req->r_tid);
2443                 req->r_resend_mds = -1;
2444                 if (req->r_direct_mode != USE_AUTH_MDS) {
2445                         dout("not using auth, setting for that now");
2446                         req->r_direct_mode = USE_AUTH_MDS;
2447                         __do_request(mdsc, req);
2448                         mutex_unlock(&mdsc->mutex);
2449                         goto out;
2450                 } else  {
2451                         int mds = __choose_mds(mdsc, req);
2452                         if (mds >= 0 && mds != req->r_session->s_mds) {
2453                                 dout("but auth changed, so resending");
2454                                 __do_request(mdsc, req);
2455                                 mutex_unlock(&mdsc->mutex);
2456                                 goto out;
2457                         }
2458                 }
2459                 dout("have to return ESTALE on request %llu", req->r_tid);
2460         }
2461
2462
2463         if (head->safe) {
2464                 req->r_got_safe = true;
2465                 __unregister_request(mdsc, req);
2466
2467                 if (req->r_got_unsafe) {
2468                         /*
2469                          * We already handled the unsafe response, now do the
2470                          * cleanup.  No need to examine the response; the MDS
2471                          * doesn't include any result info in the safe
2472                          * response.  And even if it did, there is nothing
2473                          * useful we could do with a revised return value.
2474                          */
2475                         dout("got safe reply %llu, mds%d\n", tid, mds);
2476                         list_del_init(&req->r_unsafe_item);
2477
2478                         /* last unsafe request during umount? */
2479                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2480                                 complete_all(&mdsc->safe_umount_waiters);
2481                         mutex_unlock(&mdsc->mutex);
2482                         goto out;
2483                 }
2484         } else {
2485                 req->r_got_unsafe = true;
2486                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2487                 if (req->r_unsafe_dir) {
2488                         struct ceph_inode_info *ci =
2489                                         ceph_inode(req->r_unsafe_dir);
2490                         spin_lock(&ci->i_unsafe_lock);
2491                         list_add_tail(&req->r_unsafe_dir_item,
2492                                       &ci->i_unsafe_dirops);
2493                         spin_unlock(&ci->i_unsafe_lock);
2494                 }
2495         }
2496
2497         dout("handle_reply tid %lld result %d\n", tid, result);
2498         rinfo = &req->r_reply_info;
2499         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2500         mutex_unlock(&mdsc->mutex);
2501
2502         mutex_lock(&session->s_mutex);
2503         if (err < 0) {
2504                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2505                 ceph_msg_dump(msg);
2506                 goto out_err;
2507         }
2508
2509         /* snap trace */
2510         realm = NULL;
2511         if (rinfo->snapblob_len) {
2512                 down_write(&mdsc->snap_rwsem);
2513                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2514                                 rinfo->snapblob + rinfo->snapblob_len,
2515                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2516                                 &realm);
2517                 downgrade_write(&mdsc->snap_rwsem);
2518         } else {
2519                 down_read(&mdsc->snap_rwsem);
2520         }
2521
2522         /* insert trace into our cache */
2523         mutex_lock(&req->r_fill_mutex);
2524         current->journal_info = req;
2525         err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2526         if (err == 0) {
2527                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2528                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2529                         ceph_readdir_prepopulate(req, req->r_session);
2530                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2531         }
2532         current->journal_info = NULL;
2533         mutex_unlock(&req->r_fill_mutex);
2534
2535         up_read(&mdsc->snap_rwsem);
2536         if (realm)
2537                 ceph_put_snap_realm(mdsc, realm);
2538
2539         if (err == 0 && req->r_got_unsafe && req->r_target_inode) {
2540                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
2541                 spin_lock(&ci->i_unsafe_lock);
2542                 list_add_tail(&req->r_unsafe_target_item, &ci->i_unsafe_iops);
2543                 spin_unlock(&ci->i_unsafe_lock);
2544         }
2545 out_err:
2546         mutex_lock(&mdsc->mutex);
2547         if (!req->r_aborted) {
2548                 if (err) {
2549                         req->r_err = err;
2550                 } else {
2551                         req->r_reply =  ceph_msg_get(msg);
2552                         req->r_got_result = true;
2553                 }
2554         } else {
2555                 dout("reply arrived after request %lld was aborted\n", tid);
2556         }
2557         mutex_unlock(&mdsc->mutex);
2558
2559         mutex_unlock(&session->s_mutex);
2560
2561         /* kick calling process */
2562         complete_request(mdsc, req);
2563 out:
2564         ceph_mdsc_put_request(req);
2565         return;
2566 }
2567
2568
2569
2570 /*
2571  * handle mds notification that our request has been forwarded.
2572  */
2573 static void handle_forward(struct ceph_mds_client *mdsc,
2574                            struct ceph_mds_session *session,
2575                            struct ceph_msg *msg)
2576 {
2577         struct ceph_mds_request *req;
2578         u64 tid = le64_to_cpu(msg->hdr.tid);
2579         u32 next_mds;
2580         u32 fwd_seq;
2581         int err = -EINVAL;
2582         void *p = msg->front.iov_base;
2583         void *end = p + msg->front.iov_len;
2584
2585         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2586         next_mds = ceph_decode_32(&p);
2587         fwd_seq = ceph_decode_32(&p);
2588
2589         mutex_lock(&mdsc->mutex);
2590         req = lookup_get_request(mdsc, tid);
2591         if (!req) {
2592                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2593                 goto out;  /* dup reply? */
2594         }
2595
2596         if (req->r_aborted) {
2597                 dout("forward tid %llu aborted, unregistering\n", tid);
2598                 __unregister_request(mdsc, req);
2599         } else if (fwd_seq <= req->r_num_fwd) {
2600                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2601                      tid, next_mds, req->r_num_fwd, fwd_seq);
2602         } else {
2603                 /* resend. forward race not possible; mds would drop */
2604                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2605                 BUG_ON(req->r_err);
2606                 BUG_ON(req->r_got_result);
2607                 req->r_attempts = 0;
2608                 req->r_num_fwd = fwd_seq;
2609                 req->r_resend_mds = next_mds;
2610                 put_request_session(req);
2611                 __do_request(mdsc, req);
2612         }
2613         ceph_mdsc_put_request(req);
2614 out:
2615         mutex_unlock(&mdsc->mutex);
2616         return;
2617
2618 bad:
2619         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2620 }
2621
2622 /*
2623  * handle a mds session control message
2624  */
2625 static void handle_session(struct ceph_mds_session *session,
2626                            struct ceph_msg *msg)
2627 {
2628         struct ceph_mds_client *mdsc = session->s_mdsc;
2629         u32 op;
2630         u64 seq;
2631         int mds = session->s_mds;
2632         struct ceph_mds_session_head *h = msg->front.iov_base;
2633         int wake = 0;
2634
2635         /* decode */
2636         if (msg->front.iov_len != sizeof(*h))
2637                 goto bad;
2638         op = le32_to_cpu(h->op);
2639         seq = le64_to_cpu(h->seq);
2640
2641         mutex_lock(&mdsc->mutex);
2642         if (op == CEPH_SESSION_CLOSE)
2643                 __unregister_session(mdsc, session);
2644         /* FIXME: this ttl calculation is generous */
2645         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2646         mutex_unlock(&mdsc->mutex);
2647
2648         mutex_lock(&session->s_mutex);
2649
2650         dout("handle_session mds%d %s %p state %s seq %llu\n",
2651              mds, ceph_session_op_name(op), session,
2652              ceph_session_state_name(session->s_state), seq);
2653
2654         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2655                 session->s_state = CEPH_MDS_SESSION_OPEN;
2656                 pr_info("mds%d came back\n", session->s_mds);
2657         }
2658
2659         switch (op) {
2660         case CEPH_SESSION_OPEN:
2661                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2662                         pr_info("mds%d reconnect success\n", session->s_mds);
2663                 session->s_state = CEPH_MDS_SESSION_OPEN;
2664                 renewed_caps(mdsc, session, 0);
2665                 wake = 1;
2666                 if (mdsc->stopping)
2667                         __close_session(mdsc, session);
2668                 break;
2669
2670         case CEPH_SESSION_RENEWCAPS:
2671                 if (session->s_renew_seq == seq)
2672                         renewed_caps(mdsc, session, 1);
2673                 break;
2674
2675         case CEPH_SESSION_CLOSE:
2676                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2677                         pr_info("mds%d reconnect denied\n", session->s_mds);
2678                 cleanup_session_requests(mdsc, session);
2679                 remove_session_caps(session);
2680                 wake = 2; /* for good measure */
2681                 wake_up_all(&mdsc->session_close_wq);
2682                 break;
2683
2684         case CEPH_SESSION_STALE:
2685                 pr_info("mds%d caps went stale, renewing\n",
2686                         session->s_mds);
2687                 spin_lock(&session->s_gen_ttl_lock);
2688                 session->s_cap_gen++;
2689                 session->s_cap_ttl = jiffies - 1;
2690                 spin_unlock(&session->s_gen_ttl_lock);
2691                 send_renew_caps(mdsc, session);
2692                 break;
2693
2694         case CEPH_SESSION_RECALL_STATE:
2695                 trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2696                 break;
2697
2698         case CEPH_SESSION_FLUSHMSG:
2699                 send_flushmsg_ack(mdsc, session, seq);
2700                 break;
2701
2702         case CEPH_SESSION_FORCE_RO:
2703                 dout("force_session_readonly %p\n", session);
2704                 spin_lock(&session->s_cap_lock);
2705                 session->s_readonly = true;
2706                 spin_unlock(&session->s_cap_lock);
2707                 wake_up_session_caps(session, 0);
2708                 break;
2709
2710         default:
2711                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2712                 WARN_ON(1);
2713         }
2714
2715         mutex_unlock(&session->s_mutex);
2716         if (wake) {
2717                 mutex_lock(&mdsc->mutex);
2718                 __wake_requests(mdsc, &session->s_waiting);
2719                 if (wake == 2)
2720                         kick_requests(mdsc, mds);
2721                 mutex_unlock(&mdsc->mutex);
2722         }
2723         return;
2724
2725 bad:
2726         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2727                (int)msg->front.iov_len);
2728         ceph_msg_dump(msg);
2729         return;
2730 }
2731
2732
2733 /*
2734  * called under session->mutex.
2735  */
2736 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2737                                    struct ceph_mds_session *session)
2738 {
2739         struct ceph_mds_request *req, *nreq;
2740         struct rb_node *p;
2741         int err;
2742
2743         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2744
2745         mutex_lock(&mdsc->mutex);
2746         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2747                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
2748                 if (!err) {
2749                         ceph_msg_get(req->r_request);
2750                         ceph_con_send(&session->s_con, req->r_request);
2751                 }
2752         }
2753
2754         /*
2755          * also re-send old requests when MDS enters reconnect stage. So that MDS
2756          * can process completed request in clientreplay stage.
2757          */
2758         p = rb_first(&mdsc->request_tree);
2759         while (p) {
2760                 req = rb_entry(p, struct ceph_mds_request, r_node);
2761                 p = rb_next(p);
2762                 if (req->r_got_unsafe)
2763                         continue;
2764                 if (req->r_attempts == 0)
2765                         continue; /* only old requests */
2766                 if (req->r_session &&
2767                     req->r_session->s_mds == session->s_mds) {
2768                         err = __prepare_send_request(mdsc, req,
2769                                                      session->s_mds, true);
2770                         if (!err) {
2771                                 ceph_msg_get(req->r_request);
2772                                 ceph_con_send(&session->s_con, req->r_request);
2773                         }
2774                 }
2775         }
2776         mutex_unlock(&mdsc->mutex);
2777 }
2778
2779 /*
2780  * Encode information about a cap for a reconnect with the MDS.
2781  */
2782 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2783                           void *arg)
2784 {
2785         union {
2786                 struct ceph_mds_cap_reconnect v2;
2787                 struct ceph_mds_cap_reconnect_v1 v1;
2788         } rec;
2789         size_t reclen;
2790         struct ceph_inode_info *ci;
2791         struct ceph_reconnect_state *recon_state = arg;
2792         struct ceph_pagelist *pagelist = recon_state->pagelist;
2793         char *path;
2794         int pathlen, err;
2795         u64 pathbase;
2796         struct dentry *dentry;
2797
2798         ci = cap->ci;
2799
2800         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2801              inode, ceph_vinop(inode), cap, cap->cap_id,
2802              ceph_cap_string(cap->issued));
2803         err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2804         if (err)
2805                 return err;
2806
2807         dentry = d_find_alias(inode);
2808         if (dentry) {
2809                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2810                 if (IS_ERR(path)) {
2811                         err = PTR_ERR(path);
2812                         goto out_dput;
2813                 }
2814         } else {
2815                 path = NULL;
2816                 pathlen = 0;
2817         }
2818         err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2819         if (err)
2820                 goto out_free;
2821
2822         spin_lock(&ci->i_ceph_lock);
2823         cap->seq = 0;        /* reset cap seq */
2824         cap->issue_seq = 0;  /* and issue_seq */
2825         cap->mseq = 0;       /* and migrate_seq */
2826         cap->cap_gen = cap->session->s_cap_gen;
2827
2828         if (recon_state->flock) {
2829                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2830                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2831                 rec.v2.issued = cpu_to_le32(cap->issued);
2832                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2833                 rec.v2.pathbase = cpu_to_le64(pathbase);
2834                 rec.v2.flock_len = 0;
2835                 reclen = sizeof(rec.v2);
2836         } else {
2837                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2838                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2839                 rec.v1.issued = cpu_to_le32(cap->issued);
2840                 rec.v1.size = cpu_to_le64(inode->i_size);
2841                 ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2842                 ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2843                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2844                 rec.v1.pathbase = cpu_to_le64(pathbase);
2845                 reclen = sizeof(rec.v1);
2846         }
2847         spin_unlock(&ci->i_ceph_lock);
2848
2849         if (recon_state->flock) {
2850                 int num_fcntl_locks, num_flock_locks;
2851                 struct ceph_filelock *flocks;
2852
2853 encode_again:
2854                 ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2855                 flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2856                                  sizeof(struct ceph_filelock), GFP_NOFS);
2857                 if (!flocks) {
2858                         err = -ENOMEM;
2859                         goto out_free;
2860                 }
2861                 err = ceph_encode_locks_to_buffer(inode, flocks,
2862                                                   num_fcntl_locks,
2863                                                   num_flock_locks);
2864                 if (err) {
2865                         kfree(flocks);
2866                         if (err == -ENOSPC)
2867                                 goto encode_again;
2868                         goto out_free;
2869                 }
2870                 /*
2871                  * number of encoded locks is stable, so copy to pagelist
2872                  */
2873                 rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2874                                     (num_fcntl_locks+num_flock_locks) *
2875                                     sizeof(struct ceph_filelock));
2876                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2877                 if (!err)
2878                         err = ceph_locks_to_pagelist(flocks, pagelist,
2879                                                      num_fcntl_locks,
2880                                                      num_flock_locks);
2881                 kfree(flocks);
2882         } else {
2883                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2884         }
2885
2886         recon_state->nr_caps++;
2887 out_free:
2888         kfree(path);
2889 out_dput:
2890         dput(dentry);
2891         return err;
2892 }
2893
2894
2895 /*
2896  * If an MDS fails and recovers, clients need to reconnect in order to
2897  * reestablish shared state.  This includes all caps issued through
2898  * this session _and_ the snap_realm hierarchy.  Because it's not
2899  * clear which snap realms the mds cares about, we send everything we
2900  * know about.. that ensures we'll then get any new info the
2901  * recovering MDS might have.
2902  *
2903  * This is a relatively heavyweight operation, but it's rare.
2904  *
2905  * called with mdsc->mutex held.
2906  */
2907 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2908                                struct ceph_mds_session *session)
2909 {
2910         struct ceph_msg *reply;
2911         struct rb_node *p;
2912         int mds = session->s_mds;
2913         int err = -ENOMEM;
2914         int s_nr_caps;
2915         struct ceph_pagelist *pagelist;
2916         struct ceph_reconnect_state recon_state;
2917
2918         pr_info("mds%d reconnect start\n", mds);
2919
2920         pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2921         if (!pagelist)
2922                 goto fail_nopagelist;
2923         ceph_pagelist_init(pagelist);
2924
2925         reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2926         if (!reply)
2927                 goto fail_nomsg;
2928
2929         mutex_lock(&session->s_mutex);
2930         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2931         session->s_seq = 0;
2932
2933         dout("session %p state %s\n", session,
2934              ceph_session_state_name(session->s_state));
2935
2936         spin_lock(&session->s_gen_ttl_lock);
2937         session->s_cap_gen++;
2938         spin_unlock(&session->s_gen_ttl_lock);
2939
2940         spin_lock(&session->s_cap_lock);
2941         /* don't know if session is readonly */
2942         session->s_readonly = 0;
2943         /*
2944          * notify __ceph_remove_cap() that we are composing cap reconnect.
2945          * If a cap get released before being added to the cap reconnect,
2946          * __ceph_remove_cap() should skip queuing cap release.
2947          */
2948         session->s_cap_reconnect = 1;
2949         /* drop old cap expires; we're about to reestablish that state */
2950         cleanup_cap_releases(mdsc, session);
2951
2952         /* trim unused caps to reduce MDS's cache rejoin time */
2953         if (mdsc->fsc->sb->s_root)
2954                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
2955
2956         ceph_con_close(&session->s_con);
2957         ceph_con_open(&session->s_con,
2958                       CEPH_ENTITY_TYPE_MDS, mds,
2959                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2960
2961         /* replay unsafe requests */
2962         replay_unsafe_requests(mdsc, session);
2963
2964         down_read(&mdsc->snap_rwsem);
2965
2966         /* traverse this session's caps */
2967         s_nr_caps = session->s_nr_caps;
2968         err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2969         if (err)
2970                 goto fail;
2971
2972         recon_state.nr_caps = 0;
2973         recon_state.pagelist = pagelist;
2974         recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2975         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2976         if (err < 0)
2977                 goto fail;
2978
2979         spin_lock(&session->s_cap_lock);
2980         session->s_cap_reconnect = 0;
2981         spin_unlock(&session->s_cap_lock);
2982
2983         /*
2984          * snaprealms.  we provide mds with the ino, seq (version), and
2985          * parent for all of our realms.  If the mds has any newer info,
2986          * it will tell us.
2987          */
2988         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2989                 struct ceph_snap_realm *realm =
2990                         rb_entry(p, struct ceph_snap_realm, node);
2991                 struct ceph_mds_snaprealm_reconnect sr_rec;
2992
2993                 dout(" adding snap realm %llx seq %lld parent %llx\n",
2994                      realm->ino, realm->seq, realm->parent_ino);
2995                 sr_rec.ino = cpu_to_le64(realm->ino);
2996                 sr_rec.seq = cpu_to_le64(realm->seq);
2997                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
2998                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2999                 if (err)
3000                         goto fail;
3001         }
3002
3003         if (recon_state.flock)
3004                 reply->hdr.version = cpu_to_le16(2);
3005
3006         /* raced with cap release? */
3007         if (s_nr_caps != recon_state.nr_caps) {
3008                 struct page *page = list_first_entry(&pagelist->head,
3009                                                      struct page, lru);
3010                 __le32 *addr = kmap_atomic(page);
3011                 *addr = cpu_to_le32(recon_state.nr_caps);
3012                 kunmap_atomic(addr);
3013         }
3014
3015         reply->hdr.data_len = cpu_to_le32(pagelist->length);
3016         ceph_msg_data_add_pagelist(reply, pagelist);
3017
3018         ceph_early_kick_flushing_caps(mdsc, session);
3019
3020         ceph_con_send(&session->s_con, reply);
3021
3022         mutex_unlock(&session->s_mutex);
3023
3024         mutex_lock(&mdsc->mutex);
3025         __wake_requests(mdsc, &session->s_waiting);
3026         mutex_unlock(&mdsc->mutex);
3027
3028         up_read(&mdsc->snap_rwsem);
3029         return;
3030
3031 fail:
3032         ceph_msg_put(reply);
3033         up_read(&mdsc->snap_rwsem);
3034         mutex_unlock(&session->s_mutex);
3035 fail_nomsg:
3036         ceph_pagelist_release(pagelist);
3037 fail_nopagelist:
3038         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3039         return;
3040 }
3041
3042
3043 /*
3044  * compare old and new mdsmaps, kicking requests
3045  * and closing out old connections as necessary
3046  *
3047  * called under mdsc->mutex.
3048  */
3049 static void check_new_map(struct ceph_mds_client *mdsc,
3050                           struct ceph_mdsmap *newmap,
3051                           struct ceph_mdsmap *oldmap)
3052 {
3053         int i;
3054         int oldstate, newstate;
3055         struct ceph_mds_session *s;
3056
3057         dout("check_new_map new %u old %u\n",
3058              newmap->m_epoch, oldmap->m_epoch);
3059
3060         for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
3061                 if (mdsc->sessions[i] == NULL)
3062                         continue;
3063                 s = mdsc->sessions[i];
3064                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3065                 newstate = ceph_mdsmap_get_state(newmap, i);
3066
3067                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3068                      i, ceph_mds_state_name(oldstate),
3069                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3070                      ceph_mds_state_name(newstate),
3071                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3072                      ceph_session_state_name(s->s_state));
3073
3074                 if (i >= newmap->m_max_mds ||
3075                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
3076                            ceph_mdsmap_get_addr(newmap, i),
3077                            sizeof(struct ceph_entity_addr))) {
3078                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
3079                                 /* the session never opened, just close it
3080                                  * out now */
3081                                 __wake_requests(mdsc, &s->s_waiting);
3082                                 __unregister_session(mdsc, s);
3083                         } else {
3084                                 /* just close it */
3085                                 mutex_unlock(&mdsc->mutex);
3086                                 mutex_lock(&s->s_mutex);
3087                                 mutex_lock(&mdsc->mutex);
3088                                 ceph_con_close(&s->s_con);
3089                                 mutex_unlock(&s->s_mutex);
3090                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
3091                         }
3092                 } else if (oldstate == newstate) {
3093                         continue;  /* nothing new with this mds */
3094                 }
3095
3096                 /*
3097                  * send reconnect?
3098                  */
3099                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3100                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3101                         mutex_unlock(&mdsc->mutex);
3102                         send_mds_reconnect(mdsc, s);
3103                         mutex_lock(&mdsc->mutex);
3104                 }
3105
3106                 /*
3107                  * kick request on any mds that has gone active.
3108                  */
3109                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3110                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3111                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3112                             oldstate != CEPH_MDS_STATE_STARTING)
3113                                 pr_info("mds%d recovery completed\n", s->s_mds);
3114                         kick_requests(mdsc, i);
3115                         ceph_kick_flushing_caps(mdsc, s);
3116                         wake_up_session_caps(s, 1);
3117                 }
3118         }
3119
3120         for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3121                 s = mdsc->sessions[i];
3122                 if (!s)
3123                         continue;
3124                 if (!ceph_mdsmap_is_laggy(newmap, i))
3125                         continue;
3126                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3127                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3128                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3129                         dout(" connecting to export targets of laggy mds%d\n",
3130                              i);
3131                         __open_export_target_sessions(mdsc, s);
3132                 }
3133         }
3134 }
3135
3136
3137
3138 /*
3139  * leases
3140  */
3141
3142 /*
3143  * caller must hold session s_mutex, dentry->d_lock
3144  */
3145 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3146 {
3147         struct ceph_dentry_info *di = ceph_dentry(dentry);
3148
3149         ceph_put_mds_session(di->lease_session);
3150         di->lease_session = NULL;
3151 }
3152
3153 static void handle_lease(struct ceph_mds_client *mdsc,
3154                          struct ceph_mds_session *session,
3155                          struct ceph_msg *msg)
3156 {
3157         struct super_block *sb = mdsc->fsc->sb;
3158         struct inode *inode;
3159         struct dentry *parent, *dentry;
3160         struct ceph_dentry_info *di;
3161         int mds = session->s_mds;
3162         struct ceph_mds_lease *h = msg->front.iov_base;
3163         u32 seq;
3164         struct ceph_vino vino;
3165         struct qstr dname;
3166         int release = 0;
3167
3168         dout("handle_lease from mds%d\n", mds);
3169
3170         /* decode */
3171         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3172                 goto bad;
3173         vino.ino = le64_to_cpu(h->ino);
3174         vino.snap = CEPH_NOSNAP;
3175         seq = le32_to_cpu(h->seq);
3176         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3177         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3178         if (dname.len != get_unaligned_le32(h+1))
3179                 goto bad;
3180
3181         /* lookup inode */
3182         inode = ceph_find_inode(sb, vino);
3183         dout("handle_lease %s, ino %llx %p %.*s\n",
3184              ceph_lease_op_name(h->action), vino.ino, inode,
3185              dname.len, dname.name);
3186
3187         mutex_lock(&session->s_mutex);
3188         session->s_seq++;
3189
3190         if (inode == NULL) {
3191                 dout("handle_lease no inode %llx\n", vino.ino);
3192                 goto release;
3193         }
3194
3195         /* dentry */
3196         parent = d_find_alias(inode);
3197         if (!parent) {
3198                 dout("no parent dentry on inode %p\n", inode);
3199                 WARN_ON(1);
3200                 goto release;  /* hrm... */
3201         }
3202         dname.hash = full_name_hash(dname.name, dname.len);
3203         dentry = d_lookup(parent, &dname);
3204         dput(parent);
3205         if (!dentry)
3206                 goto release;
3207
3208         spin_lock(&dentry->d_lock);
3209         di = ceph_dentry(dentry);
3210         switch (h->action) {
3211         case CEPH_MDS_LEASE_REVOKE:
3212                 if (di->lease_session == session) {
3213                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3214                                 h->seq = cpu_to_le32(di->lease_seq);
3215                         __ceph_mdsc_drop_dentry_lease(dentry);
3216                 }
3217                 release = 1;
3218                 break;
3219
3220         case CEPH_MDS_LEASE_RENEW:
3221                 if (di->lease_session == session &&
3222                     di->lease_gen == session->s_cap_gen &&
3223                     di->lease_renew_from &&
3224                     di->lease_renew_after == 0) {
3225                         unsigned long duration =
3226                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3227
3228                         di->lease_seq = seq;
3229                         di->time = di->lease_renew_from + duration;
3230                         di->lease_renew_after = di->lease_renew_from +
3231                                 (duration >> 1);
3232                         di->lease_renew_from = 0;
3233                 }
3234                 break;
3235         }
3236         spin_unlock(&dentry->d_lock);
3237         dput(dentry);
3238
3239         if (!release)
3240                 goto out;
3241
3242 release:
3243         /* let's just reuse the same message */
3244         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3245         ceph_msg_get(msg);
3246         ceph_con_send(&session->s_con, msg);
3247
3248 out:
3249         iput(inode);
3250         mutex_unlock(&session->s_mutex);
3251         return;
3252
3253 bad:
3254         pr_err("corrupt lease message\n");
3255         ceph_msg_dump(msg);
3256 }
3257
3258 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3259                               struct inode *inode,
3260                               struct dentry *dentry, char action,
3261                               u32 seq)
3262 {
3263         struct ceph_msg *msg;
3264         struct ceph_mds_lease *lease;
3265         int len = sizeof(*lease) + sizeof(u32);
3266         int dnamelen = 0;
3267
3268         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3269              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3270         dnamelen = dentry->d_name.len;
3271         len += dnamelen;
3272
3273         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3274         if (!msg)
3275                 return;
3276         lease = msg->front.iov_base;
3277         lease->action = action;
3278         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3279         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3280         lease->seq = cpu_to_le32(seq);
3281         put_unaligned_le32(dnamelen, lease + 1);
3282         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3283
3284         /*
3285          * if this is a preemptive lease RELEASE, no need to
3286          * flush request stream, since the actual request will
3287          * soon follow.
3288          */
3289         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3290
3291         ceph_con_send(&session->s_con, msg);
3292 }
3293
3294 /*
3295  * Preemptively release a lease we expect to invalidate anyway.
3296  * Pass @inode always, @dentry is optional.
3297  */
3298 void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
3299                              struct dentry *dentry)
3300 {
3301         struct ceph_dentry_info *di;
3302         struct ceph_mds_session *session;
3303         u32 seq;
3304
3305         BUG_ON(inode == NULL);
3306         BUG_ON(dentry == NULL);
3307
3308         /* is dentry lease valid? */
3309         spin_lock(&dentry->d_lock);
3310         di = ceph_dentry(dentry);
3311         if (!di || !di->lease_session ||
3312             di->lease_session->s_mds < 0 ||
3313             di->lease_gen != di->lease_session->s_cap_gen ||
3314             !time_before(jiffies, di->time)) {
3315                 dout("lease_release inode %p dentry %p -- "
3316                      "no lease\n",
3317                      inode, dentry);
3318                 spin_unlock(&dentry->d_lock);
3319                 return;
3320         }
3321
3322         /* we do have a lease on this dentry; note mds and seq */
3323         session = ceph_get_mds_session(di->lease_session);
3324         seq = di->lease_seq;
3325         __ceph_mdsc_drop_dentry_lease(dentry);
3326         spin_unlock(&dentry->d_lock);
3327
3328         dout("lease_release inode %p dentry %p to mds%d\n",
3329              inode, dentry, session->s_mds);
3330         ceph_mdsc_lease_send_msg(session, inode, dentry,
3331                                  CEPH_MDS_LEASE_RELEASE, seq);
3332         ceph_put_mds_session(session);
3333 }
3334
3335 /*
3336  * drop all leases (and dentry refs) in preparation for umount
3337  */
3338 static void drop_leases(struct ceph_mds_client *mdsc)
3339 {
3340         int i;
3341
3342         dout("drop_leases\n");
3343         mutex_lock(&mdsc->mutex);
3344         for (i = 0; i < mdsc->max_sessions; i++) {
3345                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3346                 if (!s)
3347                         continue;
3348                 mutex_unlock(&mdsc->mutex);
3349                 mutex_lock(&s->s_mutex);
3350                 mutex_unlock(&s->s_mutex);
3351                 ceph_put_mds_session(s);
3352                 mutex_lock(&mdsc->mutex);
3353         }
3354         mutex_unlock(&mdsc->mutex);
3355 }
3356
3357
3358
3359 /*
3360  * delayed work -- periodically trim expired leases, renew caps with mds
3361  */
3362 static void schedule_delayed(struct ceph_mds_client *mdsc)
3363 {
3364         int delay = 5;
3365         unsigned hz = round_jiffies_relative(HZ * delay);
3366         schedule_delayed_work(&mdsc->delayed_work, hz);
3367 }
3368
3369 static void delayed_work(struct work_struct *work)
3370 {
3371         int i;
3372         struct ceph_mds_client *mdsc =
3373                 container_of(work, struct ceph_mds_client, delayed_work.work);
3374         int renew_interval;
3375         int renew_caps;
3376
3377         dout("mdsc delayed_work\n");
3378         ceph_check_delayed_caps(mdsc);
3379
3380         mutex_lock(&mdsc->mutex);
3381         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3382         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3383                                    mdsc->last_renew_caps);
3384         if (renew_caps)
3385                 mdsc->last_renew_caps = jiffies;
3386
3387         for (i = 0; i < mdsc->max_sessions; i++) {
3388                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3389                 if (s == NULL)
3390                         continue;
3391                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3392                         dout("resending session close request for mds%d\n",
3393                              s->s_mds);
3394                         request_close_session(mdsc, s);
3395                         ceph_put_mds_session(s);
3396                         continue;
3397                 }
3398                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3399                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3400                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3401                                 pr_info("mds%d hung\n", s->s_mds);
3402                         }
3403                 }
3404                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3405                         /* this mds is failed or recovering, just wait */
3406                         ceph_put_mds_session(s);
3407                         continue;
3408                 }
3409                 mutex_unlock(&mdsc->mutex);
3410
3411                 mutex_lock(&s->s_mutex);
3412                 if (renew_caps)
3413                         send_renew_caps(mdsc, s);
3414                 else
3415                         ceph_con_keepalive(&s->s_con);
3416                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3417                     s->s_state == CEPH_MDS_SESSION_HUNG)
3418                         ceph_send_cap_releases(mdsc, s);
3419                 mutex_unlock(&s->s_mutex);
3420                 ceph_put_mds_session(s);
3421
3422                 mutex_lock(&mdsc->mutex);
3423         }
3424         mutex_unlock(&mdsc->mutex);
3425
3426         schedule_delayed(mdsc);
3427 }
3428
3429 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3430
3431 {
3432         struct ceph_mds_client *mdsc;
3433
3434         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3435         if (!mdsc)
3436                 return -ENOMEM;
3437         mdsc->fsc = fsc;
3438         fsc->mdsc = mdsc;
3439         mutex_init(&mdsc->mutex);
3440         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3441         if (mdsc->mdsmap == NULL) {
3442                 kfree(mdsc);
3443                 return -ENOMEM;
3444         }
3445
3446         init_completion(&mdsc->safe_umount_waiters);
3447         init_waitqueue_head(&mdsc->session_close_wq);
3448         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3449         mdsc->sessions = NULL;
3450         atomic_set(&mdsc->num_sessions, 0);
3451         mdsc->max_sessions = 0;
3452         mdsc->stopping = 0;
3453         mdsc->last_snap_seq = 0;
3454         init_rwsem(&mdsc->snap_rwsem);
3455         mdsc->snap_realms = RB_ROOT;
3456         INIT_LIST_HEAD(&mdsc->snap_empty);
3457         spin_lock_init(&mdsc->snap_empty_lock);
3458         mdsc->last_tid = 0;
3459         mdsc->oldest_tid = 0;
3460         mdsc->request_tree = RB_ROOT;
3461         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3462         mdsc->last_renew_caps = jiffies;
3463         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3464         spin_lock_init(&mdsc->cap_delay_lock);
3465         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3466         spin_lock_init(&mdsc->snap_flush_lock);
3467         mdsc->last_cap_flush_tid = 1;
3468         mdsc->cap_flush_tree = RB_ROOT;
3469         INIT_LIST_HEAD(&mdsc->cap_dirty);
3470         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3471         mdsc->num_cap_flushing = 0;
3472         spin_lock_init(&mdsc->cap_dirty_lock);
3473         init_waitqueue_head(&mdsc->cap_flushing_wq);
3474         spin_lock_init(&mdsc->dentry_lru_lock);
3475         INIT_LIST_HEAD(&mdsc->dentry_lru);
3476
3477         ceph_caps_init(mdsc);
3478         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3479
3480         init_rwsem(&mdsc->pool_perm_rwsem);
3481         mdsc->pool_perm_tree = RB_ROOT;
3482
3483         return 0;
3484 }
3485
3486 /*
3487  * Wait for safe replies on open mds requests.  If we time out, drop
3488  * all requests from the tree to avoid dangling dentry refs.
3489  */
3490 static void wait_requests(struct ceph_mds_client *mdsc)
3491 {
3492         struct ceph_options *opts = mdsc->fsc->client->options;
3493         struct ceph_mds_request *req;
3494
3495         mutex_lock(&mdsc->mutex);
3496         if (__get_oldest_req(mdsc)) {
3497                 mutex_unlock(&mdsc->mutex);
3498
3499                 dout("wait_requests waiting for requests\n");
3500                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3501                                     ceph_timeout_jiffies(opts->mount_timeout));
3502
3503                 /* tear down remaining requests */
3504                 mutex_lock(&mdsc->mutex);
3505                 while ((req = __get_oldest_req(mdsc))) {
3506                         dout("wait_requests timed out on tid %llu\n",
3507                              req->r_tid);
3508                         __unregister_request(mdsc, req);
3509                 }
3510         }
3511         mutex_unlock(&mdsc->mutex);
3512         dout("wait_requests done\n");
3513 }
3514
3515 /*
3516  * called before mount is ro, and before dentries are torn down.
3517  * (hmm, does this still race with new lookups?)
3518  */
3519 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3520 {
3521         dout("pre_umount\n");
3522         mdsc->stopping = 1;
3523
3524         drop_leases(mdsc);
3525         ceph_flush_dirty_caps(mdsc);
3526         wait_requests(mdsc);
3527
3528         /*
3529          * wait for reply handlers to drop their request refs and
3530          * their inode/dcache refs
3531          */
3532         ceph_msgr_flush();
3533 }
3534
3535 /*
3536  * wait for all write mds requests to flush.
3537  */
3538 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3539 {
3540         struct ceph_mds_request *req = NULL, *nextreq;
3541         struct rb_node *n;
3542
3543         mutex_lock(&mdsc->mutex);
3544         dout("wait_unsafe_requests want %lld\n", want_tid);
3545 restart:
3546         req = __get_oldest_req(mdsc);
3547         while (req && req->r_tid <= want_tid) {
3548                 /* find next request */
3549                 n = rb_next(&req->r_node);
3550                 if (n)
3551                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3552                 else
3553                         nextreq = NULL;
3554                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
3555                     (req->r_op & CEPH_MDS_OP_WRITE)) {
3556                         /* write op */
3557                         ceph_mdsc_get_request(req);
3558                         if (nextreq)
3559                                 ceph_mdsc_get_request(nextreq);
3560                         mutex_unlock(&mdsc->mutex);
3561                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3562                              req->r_tid, want_tid);
3563                         wait_for_completion(&req->r_safe_completion);
3564                         mutex_lock(&mdsc->mutex);
3565                         ceph_mdsc_put_request(req);
3566                         if (!nextreq)
3567                                 break;  /* next dne before, so we're done! */
3568                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3569                                 /* next request was removed from tree */
3570                                 ceph_mdsc_put_request(nextreq);
3571                                 goto restart;
3572                         }
3573                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3574                 }
3575                 req = nextreq;
3576         }
3577         mutex_unlock(&mdsc->mutex);
3578         dout("wait_unsafe_requests done\n");
3579 }
3580
3581 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3582 {
3583         u64 want_tid, want_flush, want_snap;
3584
3585         if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
3586                 return;
3587
3588         dout("sync\n");
3589         mutex_lock(&mdsc->mutex);
3590         want_tid = mdsc->last_tid;
3591         mutex_unlock(&mdsc->mutex);
3592
3593         ceph_flush_dirty_caps(mdsc);
3594         spin_lock(&mdsc->cap_dirty_lock);
3595         want_flush = mdsc->last_cap_flush_tid;
3596         spin_unlock(&mdsc->cap_dirty_lock);
3597
3598         down_read(&mdsc->snap_rwsem);
3599         want_snap = mdsc->last_snap_seq;
3600         up_read(&mdsc->snap_rwsem);
3601
3602         dout("sync want tid %lld flush_seq %lld snap_seq %lld\n",
3603              want_tid, want_flush, want_snap);
3604
3605         wait_unsafe_requests(mdsc, want_tid);
3606         wait_caps_flush(mdsc, want_flush, want_snap);
3607 }
3608
3609 /*
3610  * true if all sessions are closed, or we force unmount
3611  */
3612 static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3613 {
3614         if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
3615                 return true;
3616         return atomic_read(&mdsc->num_sessions) == 0;
3617 }
3618
3619 /*
3620  * called after sb is ro.
3621  */
3622 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3623 {
3624         struct ceph_options *opts = mdsc->fsc->client->options;
3625         struct ceph_mds_session *session;
3626         int i;
3627
3628         dout("close_sessions\n");
3629
3630         /* close sessions */
3631         mutex_lock(&mdsc->mutex);
3632         for (i = 0; i < mdsc->max_sessions; i++) {
3633                 session = __ceph_lookup_mds_session(mdsc, i);
3634                 if (!session)
3635                         continue;
3636                 mutex_unlock(&mdsc->mutex);
3637                 mutex_lock(&session->s_mutex);
3638                 __close_session(mdsc, session);
3639                 mutex_unlock(&session->s_mutex);
3640                 ceph_put_mds_session(session);
3641                 mutex_lock(&mdsc->mutex);
3642         }
3643         mutex_unlock(&mdsc->mutex);
3644
3645         dout("waiting for sessions to close\n");
3646         wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3647                            ceph_timeout_jiffies(opts->mount_timeout));
3648
3649         /* tear down remaining sessions */
3650         mutex_lock(&mdsc->mutex);
3651         for (i = 0; i < mdsc->max_sessions; i++) {
3652                 if (mdsc->sessions[i]) {
3653                         session = get_session(mdsc->sessions[i]);
3654                         __unregister_session(mdsc, session);
3655                         mutex_unlock(&mdsc->mutex);
3656                         mutex_lock(&session->s_mutex);
3657                         remove_session_caps(session);
3658                         mutex_unlock(&session->s_mutex);
3659                         ceph_put_mds_session(session);
3660                         mutex_lock(&mdsc->mutex);
3661                 }
3662         }
3663         WARN_ON(!list_empty(&mdsc->cap_delay_list));
3664         mutex_unlock(&mdsc->mutex);
3665
3666         ceph_cleanup_empty_realms(mdsc);
3667
3668         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3669
3670         dout("stopped\n");
3671 }
3672
3673 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
3674 {
3675         struct ceph_mds_session *session;
3676         int mds;
3677
3678         dout("force umount\n");
3679
3680         mutex_lock(&mdsc->mutex);
3681         for (mds = 0; mds < mdsc->max_sessions; mds++) {
3682                 session = __ceph_lookup_mds_session(mdsc, mds);
3683                 if (!session)
3684                         continue;
3685                 mutex_unlock(&mdsc->mutex);
3686                 mutex_lock(&session->s_mutex);
3687                 __close_session(mdsc, session);
3688                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
3689                         cleanup_session_requests(mdsc, session);
3690                         remove_session_caps(session);
3691                 }
3692                 mutex_unlock(&session->s_mutex);
3693                 ceph_put_mds_session(session);
3694                 mutex_lock(&mdsc->mutex);
3695                 kick_requests(mdsc, mds);
3696         }
3697         __wake_requests(mdsc, &mdsc->waiting_for_map);
3698         mutex_unlock(&mdsc->mutex);
3699 }
3700
3701 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3702 {
3703         dout("stop\n");
3704         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3705         if (mdsc->mdsmap)
3706                 ceph_mdsmap_destroy(mdsc->mdsmap);
3707         kfree(mdsc->sessions);
3708         ceph_caps_finalize(mdsc);
3709         ceph_pool_perm_destroy(mdsc);
3710 }
3711
3712 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3713 {
3714         struct ceph_mds_client *mdsc = fsc->mdsc;
3715
3716         dout("mdsc_destroy %p\n", mdsc);
3717         ceph_mdsc_stop(mdsc);
3718
3719         /* flush out any connection work with references to us */
3720         ceph_msgr_flush();
3721
3722         fsc->mdsc = NULL;
3723         kfree(mdsc);
3724         dout("mdsc_destroy %p done\n", mdsc);
3725 }
3726
3727
3728 /*
3729  * handle mds map update.
3730  */
3731 void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3732 {
3733         u32 epoch;
3734         u32 maplen;
3735         void *p = msg->front.iov_base;
3736         void *end = p + msg->front.iov_len;
3737         struct ceph_mdsmap *newmap, *oldmap;
3738         struct ceph_fsid fsid;
3739         int err = -EINVAL;
3740
3741         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3742         ceph_decode_copy(&p, &fsid, sizeof(fsid));
3743         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3744                 return;
3745         epoch = ceph_decode_32(&p);
3746         maplen = ceph_decode_32(&p);
3747         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3748
3749         /* do we need it? */
3750         mutex_lock(&mdsc->mutex);
3751         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3752                 dout("handle_map epoch %u <= our %u\n",
3753                      epoch, mdsc->mdsmap->m_epoch);
3754                 mutex_unlock(&mdsc->mutex);
3755                 return;
3756         }
3757
3758         newmap = ceph_mdsmap_decode(&p, end);
3759         if (IS_ERR(newmap)) {
3760                 err = PTR_ERR(newmap);
3761                 goto bad_unlock;
3762         }
3763
3764         /* swap into place */
3765         if (mdsc->mdsmap) {
3766                 oldmap = mdsc->mdsmap;
3767                 mdsc->mdsmap = newmap;
3768                 check_new_map(mdsc, newmap, oldmap);
3769                 ceph_mdsmap_destroy(oldmap);
3770         } else {
3771                 mdsc->mdsmap = newmap;  /* first mds map */
3772         }
3773         mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3774
3775         __wake_requests(mdsc, &mdsc->waiting_for_map);
3776         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
3777                           mdsc->mdsmap->m_epoch);
3778
3779         mutex_unlock(&mdsc->mutex);
3780         schedule_delayed(mdsc);
3781         return;
3782
3783 bad_unlock:
3784         mutex_unlock(&mdsc->mutex);
3785 bad:
3786         pr_err("error decoding mdsmap %d\n", err);
3787         return;
3788 }
3789
3790 static struct ceph_connection *con_get(struct ceph_connection *con)
3791 {
3792         struct ceph_mds_session *s = con->private;
3793
3794         if (get_session(s)) {
3795                 dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3796                 return con;
3797         }
3798         dout("mdsc con_get %p FAIL\n", s);
3799         return NULL;
3800 }
3801
3802 static void con_put(struct ceph_connection *con)
3803 {
3804         struct ceph_mds_session *s = con->private;
3805
3806         dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3807         ceph_put_mds_session(s);
3808 }
3809
3810 /*
3811  * if the client is unresponsive for long enough, the mds will kill
3812  * the session entirely.
3813  */
3814 static void peer_reset(struct ceph_connection *con)
3815 {
3816         struct ceph_mds_session *s = con->private;
3817         struct ceph_mds_client *mdsc = s->s_mdsc;
3818
3819         pr_warn("mds%d closed our session\n", s->s_mds);
3820         send_mds_reconnect(mdsc, s);
3821 }
3822
3823 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3824 {
3825         struct ceph_mds_session *s = con->private;
3826         struct ceph_mds_client *mdsc = s->s_mdsc;
3827         int type = le16_to_cpu(msg->hdr.type);
3828
3829         mutex_lock(&mdsc->mutex);
3830         if (__verify_registered_session(mdsc, s) < 0) {
3831                 mutex_unlock(&mdsc->mutex);
3832                 goto out;
3833         }
3834         mutex_unlock(&mdsc->mutex);
3835
3836         switch (type) {
3837         case CEPH_MSG_MDS_MAP:
3838                 ceph_mdsc_handle_map(mdsc, msg);
3839                 break;
3840         case CEPH_MSG_CLIENT_SESSION:
3841                 handle_session(s, msg);
3842                 break;
3843         case CEPH_MSG_CLIENT_REPLY:
3844                 handle_reply(s, msg);
3845                 break;
3846         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3847                 handle_forward(mdsc, s, msg);
3848                 break;
3849         case CEPH_MSG_CLIENT_CAPS:
3850                 ceph_handle_caps(s, msg);
3851                 break;
3852         case CEPH_MSG_CLIENT_SNAP:
3853                 ceph_handle_snap(mdsc, s, msg);
3854                 break;
3855         case CEPH_MSG_CLIENT_LEASE:
3856                 handle_lease(mdsc, s, msg);
3857                 break;
3858
3859         default:
3860                 pr_err("received unknown message type %d %s\n", type,
3861                        ceph_msg_type_name(type));
3862         }
3863 out:
3864         ceph_msg_put(msg);
3865 }
3866
3867 /*
3868  * authentication
3869  */
3870
3871 /*
3872  * Note: returned pointer is the address of a structure that's
3873  * managed separately.  Caller must *not* attempt to free it.
3874  */
3875 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3876                                         int *proto, int force_new)
3877 {
3878         struct ceph_mds_session *s = con->private;
3879         struct ceph_mds_client *mdsc = s->s_mdsc;
3880         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3881         struct ceph_auth_handshake *auth = &s->s_auth;
3882
3883         if (force_new && auth->authorizer) {
3884                 ceph_auth_destroy_authorizer(auth->authorizer);
3885                 auth->authorizer = NULL;
3886         }
3887         if (!auth->authorizer) {
3888                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3889                                                       auth);
3890                 if (ret)
3891                         return ERR_PTR(ret);
3892         } else {
3893                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3894                                                       auth);
3895                 if (ret)
3896                         return ERR_PTR(ret);
3897         }
3898         *proto = ac->protocol;
3899
3900         return auth;
3901 }
3902
3903
3904 static int verify_authorizer_reply(struct ceph_connection *con, int len)
3905 {
3906         struct ceph_mds_session *s = con->private;
3907         struct ceph_mds_client *mdsc = s->s_mdsc;
3908         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3909
3910         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3911 }
3912
3913 static int invalidate_authorizer(struct ceph_connection *con)
3914 {
3915         struct ceph_mds_session *s = con->private;
3916         struct ceph_mds_client *mdsc = s->s_mdsc;
3917         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3918
3919         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3920
3921         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3922 }
3923
3924 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3925                                 struct ceph_msg_header *hdr, int *skip)
3926 {
3927         struct ceph_msg *msg;
3928         int type = (int) le16_to_cpu(hdr->type);
3929         int front_len = (int) le32_to_cpu(hdr->front_len);
3930
3931         if (con->in_msg)
3932                 return con->in_msg;
3933
3934         *skip = 0;
3935         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3936         if (!msg) {
3937                 pr_err("unable to allocate msg type %d len %d\n",
3938                        type, front_len);
3939                 return NULL;
3940         }
3941
3942         return msg;
3943 }
3944
3945 static int mds_sign_message(struct ceph_msg *msg)
3946 {
3947        struct ceph_mds_session *s = msg->con->private;
3948        struct ceph_auth_handshake *auth = &s->s_auth;
3949
3950        return ceph_auth_sign_message(auth, msg);
3951 }
3952
3953 static int mds_check_message_signature(struct ceph_msg *msg)
3954 {
3955        struct ceph_mds_session *s = msg->con->private;
3956        struct ceph_auth_handshake *auth = &s->s_auth;
3957
3958        return ceph_auth_check_message_signature(auth, msg);
3959 }
3960
3961 static const struct ceph_connection_operations mds_con_ops = {
3962         .get = con_get,
3963         .put = con_put,
3964         .dispatch = dispatch,
3965         .get_authorizer = get_authorizer,
3966         .verify_authorizer_reply = verify_authorizer_reply,
3967         .invalidate_authorizer = invalidate_authorizer,
3968         .peer_reset = peer_reset,
3969         .alloc_msg = mds_alloc_msg,
3970         .sign_message = mds_sign_message,
3971         .check_message_signature = mds_check_message_signature,
3972 };
3973
3974 /* eof */