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  45  * are no longer valid.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         return 0;
 104 bad:
 105         return err;
 106 }
 107
 108 /*
 109  * parse a normal reply, which may contain a (dir+)dentry and/or a
 110  * target inode.
 111  */
 112 static int parse_reply_info_trace(void **p, void *end,
 113                                   struct ceph_mds_reply_info_parsed *info,
 114                                   u64 features)
 115 {
 116         int err;
 117
 118         if (info->head->is_dentry) {
 119                 err = parse_reply_info_in(p, end, &info->diri, features);
 120                 if (err < 0)
 121                         goto out_bad;
 122
 123                 if (unlikely(*p + sizeof(*info->dirfrag) > end))
 124                         goto bad;
 125                 info->dirfrag = *p;
 126                 *p += sizeof(*info->dirfrag) +
 127                         sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 128                 if (unlikely(*p > end))
 129                         goto bad;
 130
 131                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 132                 ceph_decode_need(p, end, info->dname_len, bad);
 133                 info->dname = *p;
 134                 *p += info->dname_len;
 135                 info->dlease = *p;
 136                 *p += sizeof(*info->dlease);
 137         }
 138
 139         if (info->head->is_target) {
 140                 err = parse_reply_info_in(p, end, &info->targeti, features);
 141                 if (err < 0)
 142                         goto out_bad;
 143         }
 144
 145         if (unlikely(*p != end))
 146                 goto bad;
 147         return 0;
 148
 149 bad:
 150         err = -EIO;
 151 out_bad:
 152         pr_err("problem parsing mds trace %d\n", err);
 153         return err;
 154 }
 155
 156 /*
 157  * parse readdir results
 158  */
 159 static int parse_reply_info_dir(void **p, void *end,
 160                                 struct ceph_mds_reply_info_parsed *info,
 161                                 u64 features)
 162 {
 163         u32 num, i = 0;
 164         int err;
 165
 166         info->dir_dir = *p;
 167         if (*p + sizeof(*info->dir_dir) > end)
 168                 goto bad;
 169         *p += sizeof(*info->dir_dir) +
 170                 sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 171         if (*p > end)
 172                 goto bad;
 173
 174         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 175         num = ceph_decode_32(p);
 176         info->dir_end = ceph_decode_8(p);
 177         info->dir_complete = ceph_decode_8(p);
 178         if (num == 0)
 179                 goto done;
 180
 181         BUG_ON(!info->dir_in);
 182         info->dir_dname = (void *)(info->dir_in + num);
 183         info->dir_dname_len = (void *)(info->dir_dname + num);
 184         info->dir_dlease = (void *)(info->dir_dname_len + num);
 185         if ((unsigned long)(info->dir_dlease + num) >
 186             (unsigned long)info->dir_in + info->dir_buf_size) {
 187                 pr_err("dir contents are larger than expected\n");
 188                 WARN_ON(1);
 189                 goto bad;
 190         }
 191
 192         info->dir_nr = num;
 193         while (num) {
 194                 /* dentry */
 195                 ceph_decode_need(p, end, sizeof(u32)*2, bad);
 196                 info->dir_dname_len[i] = ceph_decode_32(p);
 197                 ceph_decode_need(p, end, info->dir_dname_len[i], bad);
 198                 info->dir_dname[i] = *p;
 199                 *p += info->dir_dname_len[i];
 200                 dout("parsed dir dname '%.*s'\n", info->dir_dname_len[i],
 201                      info->dir_dname[i]);
 202                 info->dir_dlease[i] = *p;
 203                 *p += sizeof(struct ceph_mds_reply_lease);
 204
 205                 /* inode */
 206                 err = parse_reply_info_in(p, end, &info->dir_in[i], features);
 207                 if (err < 0)
 208                         goto out_bad;
 209                 i++;
 210                 num--;
 211         }
 212
 213 done:
 214         if (*p != end)
 215                 goto bad;
 216         return 0;
 217
 218 bad:
 219         err = -EIO;
 220 out_bad:
 221         pr_err("problem parsing dir contents %d\n", err);
 222         return err;
 223 }
 224
 225 /*
 226  * parse fcntl F_GETLK results
 227  */
 228 static int parse_reply_info_filelock(void **p, void *end,
 229                                      struct ceph_mds_reply_info_parsed *info,
 230                                      u64 features)
 231 {
 232         if (*p + sizeof(*info->filelock_reply) > end)
 233                 goto bad;
 234
 235         info->filelock_reply = *p;
 236         *p += sizeof(*info->filelock_reply);
 237
 238         if (unlikely(*p != end))
 239                 goto bad;
 240         return 0;
 241
 242 bad:
 243         return -EIO;
 244 }
 245
 246 /*
 247  * parse create results
 248  */
 249 static int parse_reply_info_create(void **p, void *end,
 250                                   struct ceph_mds_reply_info_parsed *info,
 251                                   u64 features)
 252 {
 253         if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 254                 if (*p == end) {
 255                         info->has_create_ino = false;
 256                 } else {
 257                         info->has_create_ino = true;
 258                         info->ino = ceph_decode_64(p);
 259                 }
 260         }
 261
 262         if (unlikely(*p != end))
 263                 goto bad;
 264         return 0;
 265
 266 bad:
 267         return -EIO;
 268 }
 269
 270 /*
 271  * parse extra results
 272  */
 273 static int parse_reply_info_extra(void **p, void *end,
 274                                   struct ceph_mds_reply_info_parsed *info,
 275                                   u64 features)
 276 {
 277         if (info->head->op == CEPH_MDS_OP_GETFILELOCK)
 278                 return parse_reply_info_filelock(p, end, info, features);
 279         else if (info->head->op == CEPH_MDS_OP_READDIR ||
 280                  info->head->op == CEPH_MDS_OP_LSSNAP)
 281                 return parse_reply_info_dir(p, end, info, features);
 282         else if (info->head->op == CEPH_MDS_OP_CREATE)
 283                 return parse_reply_info_create(p, end, info, features);
 284         else
 285                 return -EIO;
 286 }
 287
 288 /*
 289  * parse entire mds reply
 290  */
 291 static int parse_reply_info(struct ceph_msg *msg,
 292                             struct ceph_mds_reply_info_parsed *info,
 293                             u64 features)
 294 {
 295         void *p, *end;
 296         u32 len;
 297         int err;
 298
 299         info->head = msg->front.iov_base;
 300         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 301         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 302
 303         /* trace */
 304         ceph_decode_32_safe(&p, end, len, bad);
 305         if (len > 0) {
 306                 ceph_decode_need(&p, end, len, bad);
 307                 err = parse_reply_info_trace(&p, p+len, info, features);
 308                 if (err < 0)
 309                         goto out_bad;
 310         }
 311
 312         /* extra */
 313         ceph_decode_32_safe(&p, end, len, bad);
 314         if (len > 0) {
 315                 ceph_decode_need(&p, end, len, bad);
 316                 err = parse_reply_info_extra(&p, p+len, info, features);
 317                 if (err < 0)
 318                         goto out_bad;
 319         }
 320
 321         /* snap blob */
 322         ceph_decode_32_safe(&p, end, len, bad);
 323         info->snapblob_len = len;
 324         info->snapblob = p;
 325         p += len;
 326
 327         if (p != end)
 328                 goto bad;
 329         return 0;
 330
 331 bad:
 332         err = -EIO;
 333 out_bad:
 334         pr_err("mds parse_reply err %d\n", err);
 335         return err;
 336 }
 337
 338 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 339 {
 340         if (!info->dir_in)
 341                 return;
 342         free_pages((unsigned long)info->dir_in, get_order(info->dir_buf_size));
 343 }
 344
 345
 346 /*
 347  * sessions
 348  */
 349 const char *ceph_session_state_name(int s)
 350 {
 351         switch (s) {
 352         case CEPH_MDS_SESSION_NEW: return "new";
 353         case CEPH_MDS_SESSION_OPENING: return "opening";
 354         case CEPH_MDS_SESSION_OPEN: return "open";
 355         case CEPH_MDS_SESSION_HUNG: return "hung";
 356         case CEPH_MDS_SESSION_CLOSING: return "closing";
 357         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 358         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 359         default: return "???";
 360         }
 361 }
 362
 363 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 364 {
 365         if (atomic_inc_not_zero(&s->s_ref)) {
 366                 dout("mdsc get_session %p %d -> %d\n", s,
 367                      atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
 368                 return s;
 369         } else {
 370                 dout("mdsc get_session %p 0 -- FAIL", s);
 371                 return NULL;
 372         }
 373 }
 374
 375 void ceph_put_mds_session(struct ceph_mds_session *s)
 376 {
 377         dout("mdsc put_session %p %d -> %d\n", s,
 378              atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
 379         if (atomic_dec_and_test(&s->s_ref)) {
 380                 if (s->s_auth.authorizer)
 381                         ceph_auth_destroy_authorizer(
 382                                 s->s_mdsc->fsc->client->monc.auth,
 383                                 s->s_auth.authorizer);
 384                 kfree(s);
 385         }
 386 }
 387
 388 /*
 389  * called under mdsc->mutex
 390  */
 391 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 392                                                    int mds)
 393 {
 394         struct ceph_mds_session *session;
 395
 396         if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
 397                 return NULL;
 398         session = mdsc->sessions[mds];
 399         dout("lookup_mds_session %p %d\n", session,
 400              atomic_read(&session->s_ref));
 401         get_session(session);
 402         return session;
 403 }
 404
 405 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 406 {
 407         if (mds >= mdsc->max_sessions)
 408                 return false;
 409         return mdsc->sessions[mds];
 410 }
 411
 412 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 413                                        struct ceph_mds_session *s)
 414 {
 415         if (s->s_mds >= mdsc->max_sessions ||
 416             mdsc->sessions[s->s_mds] != s)
 417                 return -ENOENT;
 418         return 0;
 419 }
 420
 421 /*
 422  * create+register a new session for given mds.
 423  * called under mdsc->mutex.
 424  */
 425 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 426                                                  int mds)
 427 {
 428         struct ceph_mds_session *s;
 429
 430         if (mds >= mdsc->mdsmap->m_max_mds)
 431                 return ERR_PTR(-EINVAL);
 432
 433         s = kzalloc(sizeof(*s), GFP_NOFS);
 434         if (!s)
 435                 return ERR_PTR(-ENOMEM);
 436         s->s_mdsc = mdsc;
 437         s->s_mds = mds;
 438         s->s_state = CEPH_MDS_SESSION_NEW;
 439         s->s_ttl = 0;
 440         s->s_seq = 0;
 441         mutex_init(&s->s_mutex);
 442
 443         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 444
 445         spin_lock_init(&s->s_gen_ttl_lock);
 446         s->s_cap_gen = 0;
 447         s->s_cap_ttl = jiffies - 1;
 448
 449         spin_lock_init(&s->s_cap_lock);
 450         s->s_renew_requested = 0;
 451         s->s_renew_seq = 0;
 452         INIT_LIST_HEAD(&s->s_caps);
 453         s->s_nr_caps = 0;
 454         s->s_trim_caps = 0;
 455         atomic_set(&s->s_ref, 1);
 456         INIT_LIST_HEAD(&s->s_waiting);
 457         INIT_LIST_HEAD(&s->s_unsafe);
 458         s->s_num_cap_releases = 0;
 459         s->s_cap_reconnect = 0;
 460         s->s_cap_iterator = NULL;
 461         INIT_LIST_HEAD(&s->s_cap_releases);
 462         INIT_LIST_HEAD(&s->s_cap_flushing);
 463         INIT_LIST_HEAD(&s->s_cap_snaps_flushing);
 464
 465         dout("register_session mds%d\n", mds);
 466         if (mds >= mdsc->max_sessions) {
 467                 int newmax = 1 << get_count_order(mds+1);
 468                 struct ceph_mds_session **sa;
 469
 470                 dout("register_session realloc to %d\n", newmax);
 471                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 472                 if (sa == NULL)
 473                         goto fail_realloc;
 474                 if (mdsc->sessions) {
 475                         memcpy(sa, mdsc->sessions,
 476                                mdsc->max_sessions * sizeof(void *));
 477                         kfree(mdsc->sessions);
 478                 }
 479                 mdsc->sessions = sa;
 480                 mdsc->max_sessions = newmax;
 481         }
 482         mdsc->sessions[mds] = s;
 483         atomic_inc(&mdsc->num_sessions);
 484         atomic_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 485
 486         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 487                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 488
 489         return s;
 490
 491 fail_realloc:
 492         kfree(s);
 493         return ERR_PTR(-ENOMEM);
 494 }
 495
 496 /*
 497  * called under mdsc->mutex
 498  */
 499 static void __unregister_session(struct ceph_mds_client *mdsc,
 500                                struct ceph_mds_session *s)
 501 {
 502         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 503         BUG_ON(mdsc->sessions[s->s_mds] != s);
 504         mdsc->sessions[s->s_mds] = NULL;
 505         ceph_con_close(&s->s_con);
 506         ceph_put_mds_session(s);
 507         atomic_dec(&mdsc->num_sessions);
 508 }
 509
 510 /*
 511  * drop session refs in request.
 512  *
 513  * should be last request ref, or hold mdsc->mutex
 514  */
 515 static void put_request_session(struct ceph_mds_request *req)
 516 {
 517         if (req->r_session) {
 518                 ceph_put_mds_session(req->r_session);
 519                 req->r_session = NULL;
 520         }
 521 }
 522
 523 void ceph_mdsc_release_request(struct kref *kref)
 524 {
 525         struct ceph_mds_request *req = container_of(kref,
 526                                                     struct ceph_mds_request,
 527                                                     r_kref);
 528         destroy_reply_info(&req->r_reply_info);
 529         if (req->r_request)
 530                 ceph_msg_put(req->r_request);
 531         if (req->r_reply)
 532                 ceph_msg_put(req->r_reply);
 533         if (req->r_inode) {
 534                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 535                 iput(req->r_inode);
 536         }
 537         if (req->r_locked_dir)
 538                 ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
 539         iput(req->r_target_inode);
 540         if (req->r_dentry)
 541                 dput(req->r_dentry);
 542         if (req->r_old_dentry)
 543                 dput(req->r_old_dentry);
 544         if (req->r_old_dentry_dir) {
 545                 /*
 546                  * track (and drop pins for) r_old_dentry_dir
 547                  * separately, since r_old_dentry's d_parent may have
 548                  * changed between the dir mutex being dropped and
 549                  * this request being freed.
 550                  */
 551                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 552                                   CEPH_CAP_PIN);
 553                 iput(req->r_old_dentry_dir);
 554         }
 555         kfree(req->r_path1);
 556         kfree(req->r_path2);
 557         if (req->r_pagelist)
 558                 ceph_pagelist_release(req->r_pagelist);
 559         put_request_session(req);
 560         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 561         kfree(req);
 562 }
 563
 564 /*
 565  * lookup session, bump ref if found.
 566  *
 567  * called under mdsc->mutex.
 568  */
 569 static struct ceph_mds_request *__lookup_request(struct ceph_mds_client *mdsc,
 570                                              u64 tid)
 571 {
 572         struct ceph_mds_request *req;
 573         struct rb_node *n = mdsc->request_tree.rb_node;
 574
 575         while (n) {
 576                 req = rb_entry(n, struct ceph_mds_request, r_node);
 577                 if (tid < req->r_tid)
 578                         n = n->rb_left;
 579                 else if (tid > req->r_tid)
 580                         n = n->rb_right;
 581                 else {
 582                         ceph_mdsc_get_request(req);
 583                         return req;
 584                 }
 585         }
 586         return NULL;
 587 }
 588
 589 static void __insert_request(struct ceph_mds_client *mdsc,
 590                              struct ceph_mds_request *new)
 591 {
 592         struct rb_node **p = &mdsc->request_tree.rb_node;
 593         struct rb_node *parent = NULL;
 594         struct ceph_mds_request *req = NULL;
 595
 596         while (*p) {
 597                 parent = *p;
 598                 req = rb_entry(parent, struct ceph_mds_request, r_node);
 599                 if (new->r_tid < req->r_tid)
 600                         p = &(*p)->rb_left;
 601                 else if (new->r_tid > req->r_tid)
 602                         p = &(*p)->rb_right;
 603                 else
 604                         BUG();
 605         }
 606
 607         rb_link_node(&new->r_node, parent, p);
 608         rb_insert_color(&new->r_node, &mdsc->request_tree);
 609 }
 610
 611 /*
 612  * Register an in-flight request, and assign a tid.  Link to directory
 613  * are modifying (if any).
 614  *
 615  * Called under mdsc->mutex.
 616  */
 617 static void __register_request(struct ceph_mds_client *mdsc,
 618                                struct ceph_mds_request *req,
 619                                struct inode *dir)
 620 {
 621         req->r_tid = ++mdsc->last_tid;
 622         if (req->r_num_caps)
 623                 ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 624                                   req->r_num_caps);
 625         dout("__register_request %p tid %lld\n", req, req->r_tid);
 626         ceph_mdsc_get_request(req);
 627         __insert_request(mdsc, req);
 628
 629         req->r_uid = current_fsuid();
 630         req->r_gid = current_fsgid();
 631
 632         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 633                 mdsc->oldest_tid = req->r_tid;
 634
 635         if (dir) {
 636                 struct ceph_inode_info *ci = ceph_inode(dir);
 637
 638                 ihold(dir);
 639                 spin_lock(&ci->i_unsafe_lock);
 640                 req->r_unsafe_dir = dir;
 641                 list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 642                 spin_unlock(&ci->i_unsafe_lock);
 643         }
 644 }
 645
 646 static void __unregister_request(struct ceph_mds_client *mdsc,
 647                                  struct ceph_mds_request *req)
 648 {
 649         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 650
 651         if (req->r_tid == mdsc->oldest_tid) {
 652                 struct rb_node *p = rb_next(&req->r_node);
 653                 mdsc->oldest_tid = 0;
 654                 while (p) {
 655                         struct ceph_mds_request *next_req =
 656                                 rb_entry(p, struct ceph_mds_request, r_node);
 657                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 658                                 mdsc->oldest_tid = next_req->r_tid;
 659                                 break;
 660                         }
 661                         p = rb_next(p);
 662                 }
 663         }
 664
 665         rb_erase(&req->r_node, &mdsc->request_tree);
 666         RB_CLEAR_NODE(&req->r_node);
 667
 668         if (req->r_unsafe_dir) {
 669                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 670
 671                 spin_lock(&ci->i_unsafe_lock);
 672                 list_del_init(&req->r_unsafe_dir_item);
 673                 spin_unlock(&ci->i_unsafe_lock);
 674
 675                 iput(req->r_unsafe_dir);
 676                 req->r_unsafe_dir = NULL;
 677         }
 678
 679         complete_all(&req->r_safe_completion);
 680
 681         ceph_mdsc_put_request(req);
 682 }
 683
 684 /*
 685  * Choose mds to send request to next.  If there is a hint set in the
 686  * request (e.g., due to a prior forward hint from the mds), use that.
 687  * Otherwise, consult frag tree and/or caps to identify the
 688  * appropriate mds.  If all else fails, choose randomly.
 689  *
 690  * Called under mdsc->mutex.
 691  */
 692 static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 693 {
 694         /*
 695          * we don't need to worry about protecting the d_parent access
 696          * here because we never renaming inside the snapped namespace
 697          * except to resplice to another snapdir, and either the old or new
 698          * result is a valid result.
 699          */
 700         while (!IS_ROOT(dentry) && ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
 701                 dentry = dentry->d_parent;
 702         return dentry;
 703 }
 704
 705 static int __choose_mds(struct ceph_mds_client *mdsc,
 706                         struct ceph_mds_request *req)
 707 {
 708         struct inode *inode;
 709         struct ceph_inode_info *ci;
 710         struct ceph_cap *cap;
 711         int mode = req->r_direct_mode;
 712         int mds = -1;
 713         u32 hash = req->r_direct_hash;
 714         bool is_hash = req->r_direct_is_hash;
 715
 716         /*
 717          * is there a specific mds we should try?  ignore hint if we have
 718          * no session and the mds is not up (active or recovering).
 719          */
 720         if (req->r_resend_mds >= 0 &&
 721             (__have_session(mdsc, req->r_resend_mds) ||
 722              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 723                 dout("choose_mds using resend_mds mds%d\n",
 724                      req->r_resend_mds);
 725                 return req->r_resend_mds;
 726         }
 727
 728         if (mode == USE_RANDOM_MDS)
 729                 goto random;
 730
 731         inode = NULL;
 732         if (req->r_inode) {
 733                 inode = req->r_inode;
 734         } else if (req->r_dentry) {
 735                 /* ignore race with rename; old or new d_parent is okay */
 736                 struct dentry *parent = req->r_dentry->d_parent;
 737                 struct inode *dir = d_inode(parent);
 738
 739                 if (dir->i_sb != mdsc->fsc->sb) {
 740                         /* not this fs! */
 741                         inode = d_inode(req->r_dentry);
 742                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 743                         /* direct snapped/virtual snapdir requests
 744                          * based on parent dir inode */
 745                         struct dentry *dn = get_nonsnap_parent(parent);
 746                         inode = d_inode(dn);
 747                         dout("__choose_mds using nonsnap parent %p\n", inode);
 748                 } else {
 749                         /* dentry target */
 750                         inode = d_inode(req->r_dentry);
 751                         if (!inode || mode == USE_AUTH_MDS) {
 752                                 /* dir + name */
 753                                 inode = dir;
 754                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 755                                 is_hash = true;
 756                         }
 757                 }
 758         }
 759
 760         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 761              (int)hash, mode);
 762         if (!inode)
 763                 goto random;
 764         ci = ceph_inode(inode);
 765
 766         if (is_hash && S_ISDIR(inode->i_mode)) {
 767                 struct ceph_inode_frag frag;
 768                 int found;
 769
 770                 ceph_choose_frag(ci, hash, &frag, &found);
 771                 if (found) {
 772                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 773                                 u8 r;
 774
 775                                 /* choose a random replica */
 776                                 get_random_bytes(&r, 1);
 777                                 r %= frag.ndist;
 778                                 mds = frag.dist[r];
 779                                 dout("choose_mds %p %llx.%llx "
 780                                      "frag %u mds%d (%d/%d)\n",
 781                                      inode, ceph_vinop(inode),
 782                                      frag.frag, mds,
 783                                      (int)r, frag.ndist);
 784                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 785                                     CEPH_MDS_STATE_ACTIVE)
 786                                         return mds;
 787                         }
 788
 789                         /* since this file/dir wasn't known to be
 790                          * replicated, then we want to look for the
 791                          * authoritative mds. */
 792                         mode = USE_AUTH_MDS;
 793                         if (frag.mds >= 0) {
 794                                 /* choose auth mds */
 795                                 mds = frag.mds;
 796                                 dout("choose_mds %p %llx.%llx "
 797                                      "frag %u mds%d (auth)\n",
 798                                      inode, ceph_vinop(inode), frag.frag, mds);
 799                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 800                                     CEPH_MDS_STATE_ACTIVE)
 801                                         return mds;
 802                         }
 803                 }
 804         }
 805
 806         spin_lock(&ci->i_ceph_lock);
 807         cap = NULL;
 808         if (mode == USE_AUTH_MDS)
 809                 cap = ci->i_auth_cap;
 810         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 811                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 812         if (!cap) {
 813                 spin_unlock(&ci->i_ceph_lock);
 814                 goto random;
 815         }
 816         mds = cap->session->s_mds;
 817         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 818              inode, ceph_vinop(inode), mds,
 819              cap == ci->i_auth_cap ? "auth " : "", cap);
 820         spin_unlock(&ci->i_ceph_lock);
 821         return mds;
 822
 823 random:
 824         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 825         dout("choose_mds chose random mds%d\n", mds);
 826         return mds;
 827 }
 828
 829
 830 /*
 831  * session messages
 832  */
 833 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 834 {
 835         struct ceph_msg *msg;
 836         struct ceph_mds_session_head *h;
 837
 838         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 839                            false);
 840         if (!msg) {
 841                 pr_err("create_session_msg ENOMEM creating msg\n");
 842                 return NULL;
 843         }
 844         h = msg->front.iov_base;
 845         h->op = cpu_to_le32(op);
 846         h->seq = cpu_to_le64(seq);
 847
 848         return msg;
 849 }
 850
 851 /*
 852  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
 853  * to include additional client metadata fields.
 854  */
 855 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
 856 {
 857         struct ceph_msg *msg;
 858         struct ceph_mds_session_head *h;
 859         int i = -1;
 860         int metadata_bytes = 0;
 861         int metadata_key_count = 0;
 862         struct ceph_options *opt = mdsc->fsc->client->options;
 863         void *p;
 864
 865         const char* metadata[][2] = {
 866                 {"hostname", utsname()->nodename},
 867                 {"kernel_version", utsname()->release},
 868                 {"entity_id", opt->name ? opt->name : ""},
 869                 {NULL, NULL}
 870         };
 871
 872         /* Calculate serialized length of metadata */
 873         metadata_bytes = 4;  /* map length */
 874         for (i = 0; metadata[i][0] != NULL; ++i) {
 875                 metadata_bytes += 8 + strlen(metadata[i][0]) +
 876                         strlen(metadata[i][1]);
 877                 metadata_key_count++;
 878         }
 879
 880         /* Allocate the message */
 881         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + metadata_bytes,
 882                            GFP_NOFS, false);
 883         if (!msg) {
 884                 pr_err("create_session_msg ENOMEM creating msg\n");
 885                 return NULL;
 886         }
 887         h = msg->front.iov_base;
 888         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 889         h->seq = cpu_to_le64(seq);
 890
 891         /*
 892          * Serialize client metadata into waiting buffer space, using
 893          * the format that userspace expects for map<string, string>
 894          *
 895          * ClientSession messages with metadata are v2
 896          */
 897         msg->hdr.version = cpu_to_le16(2);
 898         msg->hdr.compat_version = cpu_to_le16(1);
 899
 900         /* The write pointer, following the session_head structure */
 901         p = msg->front.iov_base + sizeof(*h);
 902
 903         /* Number of entries in the map */
 904         ceph_encode_32(&p, metadata_key_count);
 905
 906         /* Two length-prefixed strings for each entry in the map */
 907         for (i = 0; metadata[i][0] != NULL; ++i) {
 908                 size_t const key_len = strlen(metadata[i][0]);
 909                 size_t const val_len = strlen(metadata[i][1]);
 910
 911                 ceph_encode_32(&p, key_len);
 912                 memcpy(p, metadata[i][0], key_len);
 913                 p += key_len;
 914                 ceph_encode_32(&p, val_len);
 915                 memcpy(p, metadata[i][1], val_len);
 916                 p += val_len;
 917         }
 918
 919         return msg;
 920 }
 921
 922 /*
 923  * send session open request.
 924  *
 925  * called under mdsc->mutex
 926  */
 927 static int __open_session(struct ceph_mds_client *mdsc,
 928                           struct ceph_mds_session *session)
 929 {
 930         struct ceph_msg *msg;
 931         int mstate;
 932         int mds = session->s_mds;
 933
 934         /* wait for mds to go active? */
 935         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 936         dout("open_session to mds%d (%s)\n", mds,
 937              ceph_mds_state_name(mstate));
 938         session->s_state = CEPH_MDS_SESSION_OPENING;
 939         session->s_renew_requested = jiffies;
 940
 941         /* send connect message */
 942         msg = create_session_open_msg(mdsc, session->s_seq);
 943         if (!msg)
 944                 return -ENOMEM;
 945         ceph_con_send(&session->s_con, msg);
 946         return 0;
 947 }
 948
 949 /*
 950  * open sessions for any export targets for the given mds
 951  *
 952  * called under mdsc->mutex
 953  */
 954 static struct ceph_mds_session *
 955 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
 956 {
 957         struct ceph_mds_session *session;
 958
 959         session = __ceph_lookup_mds_session(mdsc, target);
 960         if (!session) {
 961                 session = register_session(mdsc, target);
 962                 if (IS_ERR(session))
 963                         return session;
 964         }
 965         if (session->s_state == CEPH_MDS_SESSION_NEW ||
 966             session->s_state == CEPH_MDS_SESSION_CLOSING)
 967                 __open_session(mdsc, session);
 968
 969         return session;
 970 }
 971
 972 struct ceph_mds_session *
 973 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
 974 {
 975         struct ceph_mds_session *session;
 976
 977         dout("open_export_target_session to mds%d\n", target);
 978
 979         mutex_lock(&mdsc->mutex);
 980         session = __open_export_target_session(mdsc, target);
 981         mutex_unlock(&mdsc->mutex);
 982
 983         return session;
 984 }
 985
 986 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 987                                           struct ceph_mds_session *session)
 988 {
 989         struct ceph_mds_info *mi;
 990         struct ceph_mds_session *ts;
 991         int i, mds = session->s_mds;
 992
 993         if (mds >= mdsc->mdsmap->m_max_mds)
 994                 return;
 995
 996         mi = &mdsc->mdsmap->m_info[mds];
 997         dout("open_export_target_sessions for mds%d (%d targets)\n",
 998              session->s_mds, mi->num_export_targets);
 999
1000         for (i = 0; i < mi->num_export_targets; i++) {
1001                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1002                 if (!IS_ERR(ts))
1003                         ceph_put_mds_session(ts);
1004         }
1005 }
1006
1007 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1008                                            struct ceph_mds_session *session)
1009 {
1010         mutex_lock(&mdsc->mutex);
1011         __open_export_target_sessions(mdsc, session);
1012         mutex_unlock(&mdsc->mutex);
1013 }
1014
1015 /*
1016  * session caps
1017  */
1018
1019 /* caller holds s_cap_lock, we drop it */
1020 static void cleanup_cap_releases(struct ceph_mds_client *mdsc,
1021                                  struct ceph_mds_session *session)
1022         __releases(session->s_cap_lock)
1023 {
1024         LIST_HEAD(tmp_list);
1025         list_splice_init(&session->s_cap_releases, &tmp_list);
1026         session->s_num_cap_releases = 0;
1027         spin_unlock(&session->s_cap_lock);
1028
1029         dout("cleanup_cap_releases mds%d\n", session->s_mds);
1030         while (!list_empty(&tmp_list)) {
1031                 struct ceph_cap *cap;
1032                 /* zero out the in-progress message */
1033                 cap = list_first_entry(&tmp_list,
1034                                         struct ceph_cap, session_caps);
1035                 list_del(&cap->session_caps);
1036                 ceph_put_cap(mdsc, cap);
1037         }
1038 }
1039
1040 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1041                                      struct ceph_mds_session *session)
1042 {
1043         struct ceph_mds_request *req;
1044         struct rb_node *p;
1045
1046         dout("cleanup_session_requests mds%d\n", session->s_mds);
1047         mutex_lock(&mdsc->mutex);
1048         while (!list_empty(&session->s_unsafe)) {
1049                 req = list_first_entry(&session->s_unsafe,
1050                                        struct ceph_mds_request, r_unsafe_item);
1051                 list_del_init(&req->r_unsafe_item);
1052                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1053                                     req->r_tid);
1054                 __unregister_request(mdsc, req);
1055         }
1056         /* zero r_attempts, so kick_requests() will re-send requests */
1057         p = rb_first(&mdsc->request_tree);
1058         while (p) {
1059                 req = rb_entry(p, struct ceph_mds_request, r_node);
1060                 p = rb_next(p);
1061                 if (req->r_session &&
1062                     req->r_session->s_mds == session->s_mds)
1063                         req->r_attempts = 0;
1064         }
1065         mutex_unlock(&mdsc->mutex);
1066 }
1067
1068 /*
1069  * Helper to safely iterate over all caps associated with a session, with
1070  * special care taken to handle a racing __ceph_remove_cap().
1071  *
1072  * Caller must hold session s_mutex.
1073  */
1074 static int iterate_session_caps(struct ceph_mds_session *session,
1075                                  int (*cb)(struct inode *, struct ceph_cap *,
1076                                             void *), void *arg)
1077 {
1078         struct list_head *p;
1079         struct ceph_cap *cap;
1080         struct inode *inode, *last_inode = NULL;
1081         struct ceph_cap *old_cap = NULL;
1082         int ret;
1083
1084         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1085         spin_lock(&session->s_cap_lock);
1086         p = session->s_caps.next;
1087         while (p != &session->s_caps) {
1088                 cap = list_entry(p, struct ceph_cap, session_caps);
1089                 inode = igrab(&cap->ci->vfs_inode);
1090                 if (!inode) {
1091                         p = p->next;
1092                         continue;
1093                 }
1094                 session->s_cap_iterator = cap;
1095                 spin_unlock(&session->s_cap_lock);
1096
1097                 if (last_inode) {
1098                         iput(last_inode);
1099                         last_inode = NULL;
1100                 }
1101                 if (old_cap) {
1102                         ceph_put_cap(session->s_mdsc, old_cap);
1103                         old_cap = NULL;
1104                 }
1105
1106                 ret = cb(inode, cap, arg);
1107                 last_inode = inode;
1108
1109                 spin_lock(&session->s_cap_lock);
1110                 p = p->next;
1111                 if (cap->ci == NULL) {
1112                         dout("iterate_session_caps  finishing cap %p removal\n",
1113                              cap);
1114                         BUG_ON(cap->session != session);
1115                         cap->session = NULL;
1116                         list_del_init(&cap->session_caps);
1117                         session->s_nr_caps--;
1118                         if (cap->queue_release) {
1119                                 list_add_tail(&cap->session_caps,
1120                                               &session->s_cap_releases);
1121                                 session->s_num_cap_releases++;
1122                         } else {
1123                                 old_cap = cap;  /* put_cap it w/o locks held */
1124                         }
1125                 }
1126                 if (ret < 0)
1127                         goto out;
1128         }
1129         ret = 0;
1130 out:
1131         session->s_cap_iterator = NULL;
1132         spin_unlock(&session->s_cap_lock);
1133
1134         iput(last_inode);
1135         if (old_cap)
1136                 ceph_put_cap(session->s_mdsc, old_cap);
1137
1138         return ret;
1139 }
1140
1141 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1142                                   void *arg)
1143 {
1144         struct ceph_inode_info *ci = ceph_inode(inode);
1145         LIST_HEAD(to_remove);
1146         int drop = 0;
1147
1148         dout("removing cap %p, ci is %p, inode is %p\n",
1149              cap, ci, &ci->vfs_inode);
1150         spin_lock(&ci->i_ceph_lock);
1151         __ceph_remove_cap(cap, false);
1152         if (!ci->i_auth_cap) {
1153                 struct ceph_cap_flush *cf;
1154                 struct ceph_mds_client *mdsc =
1155                         ceph_sb_to_client(inode->i_sb)->mdsc;
1156
1157                 while (true) {
1158                         struct rb_node *n = rb_first(&ci->i_cap_flush_tree);
1159                         if (!n)
1160                                 break;
1161                         cf = rb_entry(n, struct ceph_cap_flush, i_node);
1162                         rb_erase(&cf->i_node, &ci->i_cap_flush_tree);
1163                         list_add(&cf->list, &to_remove);
1164                 }
1165
1166                 spin_lock(&mdsc->cap_dirty_lock);
1167
1168                 list_for_each_entry(cf, &to_remove, list)
1169                         rb_erase(&cf->g_node, &mdsc->cap_flush_tree);
1170
1171                 if (!list_empty(&ci->i_dirty_item)) {
1172                         pr_warn_ratelimited(
1173                                 " dropping dirty %s state for %p %lld\n",
1174                                 ceph_cap_string(ci->i_dirty_caps),
1175                                 inode, ceph_ino(inode));
1176                         ci->i_dirty_caps = 0;
1177                         list_del_init(&ci->i_dirty_item);
1178                         drop = 1;
1179                 }
1180                 if (!list_empty(&ci->i_flushing_item)) {
1181                         pr_warn_ratelimited(
1182                                 " dropping dirty+flushing %s state for %p %lld\n",
1183                                 ceph_cap_string(ci->i_flushing_caps),
1184                                 inode, ceph_ino(inode));
1185                         ci->i_flushing_caps = 0;
1186                         list_del_init(&ci->i_flushing_item);
1187                         mdsc->num_cap_flushing--;
1188                         drop = 1;
1189                 }
1190                 spin_unlock(&mdsc->cap_dirty_lock);
1191
1192                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1193                         list_add(&ci->i_prealloc_cap_flush->list, &to_remove);
1194                         ci->i_prealloc_cap_flush = NULL;
1195                 }
1196         }
1197         spin_unlock(&ci->i_ceph_lock);
1198         while (!list_empty(&to_remove)) {
1199                 struct ceph_cap_flush *cf;
1200                 cf = list_first_entry(&to_remove,
1201                                       struct ceph_cap_flush, list);
1202                 list_del(&cf->list);
1203                 ceph_free_cap_flush(cf);
1204         }
1205         while (drop--)
1206                 iput(inode);
1207         return 0;
1208 }
1209
1210 /*
1211  * caller must hold session s_mutex
1212  */
1213 static void remove_session_caps(struct ceph_mds_session *session)
1214 {
1215         dout("remove_session_caps on %p\n", session);
1216         iterate_session_caps(session, remove_session_caps_cb, NULL);
1217
1218         spin_lock(&session->s_cap_lock);
1219         if (session->s_nr_caps > 0) {
1220                 struct super_block *sb = session->s_mdsc->fsc->sb;
1221                 struct inode *inode;
1222                 struct ceph_cap *cap, *prev = NULL;
1223                 struct ceph_vino vino;
1224                 /*
1225                  * iterate_session_caps() skips inodes that are being
1226                  * deleted, we need to wait until deletions are complete.
1227                  * __wait_on_freeing_inode() is designed for the job,
1228                  * but it is not exported, so use lookup inode function
1229                  * to access it.
1230                  */
1231                 while (!list_empty(&session->s_caps)) {
1232                         cap = list_entry(session->s_caps.next,
1233                                          struct ceph_cap, session_caps);
1234                         if (cap == prev)
1235                                 break;
1236                         prev = cap;
1237                         vino = cap->ci->i_vino;
1238                         spin_unlock(&session->s_cap_lock);
1239
1240                         inode = ceph_find_inode(sb, vino);
1241                         iput(inode);
1242
1243                         spin_lock(&session->s_cap_lock);
1244                 }
1245         }
1246
1247         // drop cap expires and unlock s_cap_lock
1248         cleanup_cap_releases(session->s_mdsc, session);
1249
1250         BUG_ON(session->s_nr_caps > 0);
1251         BUG_ON(!list_empty(&session->s_cap_flushing));
1252 }
1253
1254 /*
1255  * wake up any threads waiting on this session's caps.  if the cap is
1256  * old (didn't get renewed on the client reconnect), remove it now.
1257  *
1258  * caller must hold s_mutex.
1259  */
1260 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1261                               void *arg)
1262 {
1263         struct ceph_inode_info *ci = ceph_inode(inode);
1264
1265         wake_up_all(&ci->i_cap_wq);
1266         if (arg) {
1267                 spin_lock(&ci->i_ceph_lock);
1268                 ci->i_wanted_max_size = 0;
1269                 ci->i_requested_max_size = 0;
1270                 spin_unlock(&ci->i_ceph_lock);
1271         }
1272         return 0;
1273 }
1274
1275 static void wake_up_session_caps(struct ceph_mds_session *session,
1276                                  int reconnect)
1277 {
1278         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1279         iterate_session_caps(session, wake_up_session_cb,
1280                              (void *)(unsigned long)reconnect);
1281 }
1282
1283 /*
1284  * Send periodic message to MDS renewing all currently held caps.  The
1285  * ack will reset the expiration for all caps from this session.
1286  *
1287  * caller holds s_mutex
1288  */
1289 static int send_renew_caps(struct ceph_mds_client *mdsc,
1290                            struct ceph_mds_session *session)
1291 {
1292         struct ceph_msg *msg;
1293         int state;
1294
1295         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1296             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1297                 pr_info("mds%d caps stale\n", session->s_mds);
1298         session->s_renew_requested = jiffies;
1299
1300         /* do not try to renew caps until a recovering mds has reconnected
1301          * with its clients. */
1302         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1303         if (state < CEPH_MDS_STATE_RECONNECT) {
1304                 dout("send_renew_caps ignoring mds%d (%s)\n",
1305                      session->s_mds, ceph_mds_state_name(state));
1306                 return 0;
1307         }
1308
1309         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1310                 ceph_mds_state_name(state));
1311         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1312                                  ++session->s_renew_seq);
1313         if (!msg)
1314                 return -ENOMEM;
1315         ceph_con_send(&session->s_con, msg);
1316         return 0;
1317 }
1318
1319 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1320                              struct ceph_mds_session *session, u64 seq)
1321 {
1322         struct ceph_msg *msg;
1323
1324         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1325              session->s_mds, ceph_session_state_name(session->s_state), seq);
1326         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1327         if (!msg)
1328                 return -ENOMEM;
1329         ceph_con_send(&session->s_con, msg);
1330         return 0;
1331 }
1332
1333
1334 /*
1335  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1336  *
1337  * Called under session->s_mutex
1338  */
1339 static void renewed_caps(struct ceph_mds_client *mdsc,
1340                          struct ceph_mds_session *session, int is_renew)
1341 {
1342         int was_stale;
1343         int wake = 0;
1344
1345         spin_lock(&session->s_cap_lock);
1346         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1347
1348         session->s_cap_ttl = session->s_renew_requested +
1349                 mdsc->mdsmap->m_session_timeout*HZ;
1350
1351         if (was_stale) {
1352                 if (time_before(jiffies, session->s_cap_ttl)) {
1353                         pr_info("mds%d caps renewed\n", session->s_mds);
1354                         wake = 1;
1355                 } else {
1356                         pr_info("mds%d caps still stale\n", session->s_mds);
1357                 }
1358         }
1359         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1360              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1361              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1362         spin_unlock(&session->s_cap_lock);
1363
1364         if (wake)
1365                 wake_up_session_caps(session, 0);
1366 }
1367
1368 /*
1369  * send a session close request
1370  */
1371 static int request_close_session(struct ceph_mds_client *mdsc,
1372                                  struct ceph_mds_session *session)
1373 {
1374         struct ceph_msg *msg;
1375
1376         dout("request_close_session mds%d state %s seq %lld\n",
1377              session->s_mds, ceph_session_state_name(session->s_state),
1378              session->s_seq);
1379         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1380         if (!msg)
1381                 return -ENOMEM;
1382         ceph_con_send(&session->s_con, msg);
1383         return 0;
1384 }
1385
1386 /*
1387  * Called with s_mutex held.
1388  */
1389 static int __close_session(struct ceph_mds_client *mdsc,
1390                          struct ceph_mds_session *session)
1391 {
1392         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1393                 return 0;
1394         session->s_state = CEPH_MDS_SESSION_CLOSING;
1395         return request_close_session(mdsc, session);
1396 }
1397
1398 /*
1399  * Trim old(er) caps.
1400  *
1401  * Because we can't cache an inode without one or more caps, we do
1402  * this indirectly: if a cap is unused, we prune its aliases, at which
1403  * point the inode will hopefully get dropped to.
1404  *
1405  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1406  * memory pressure from the MDS, though, so it needn't be perfect.
1407  */
1408 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1409 {
1410         struct ceph_mds_session *session = arg;
1411         struct ceph_inode_info *ci = ceph_inode(inode);
1412         int used, wanted, oissued, mine;
1413
1414         if (session->s_trim_caps <= 0)
1415                 return -1;
1416
1417         spin_lock(&ci->i_ceph_lock);
1418         mine = cap->issued | cap->implemented;
1419         used = __ceph_caps_used(ci);
1420         wanted = __ceph_caps_file_wanted(ci);
1421         oissued = __ceph_caps_issued_other(ci, cap);
1422
1423         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1424              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1425              ceph_cap_string(used), ceph_cap_string(wanted));
1426         if (cap == ci->i_auth_cap) {
1427                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1428                     !list_empty(&ci->i_cap_snaps))
1429                         goto out;
1430                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1431                         goto out;
1432         }
1433         if ((used | wanted) & ~oissued & mine)
1434                 goto out;   /* we need these caps */
1435
1436         session->s_trim_caps--;
1437         if (oissued) {
1438                 /* we aren't the only cap.. just remove us */
1439                 __ceph_remove_cap(cap, true);
1440         } else {
1441                 /* try to drop referring dentries */
1442                 spin_unlock(&ci->i_ceph_lock);
1443                 d_prune_aliases(inode);
1444                 dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1445                      inode, cap, atomic_read(&inode->i_count));
1446                 return 0;
1447         }
1448
1449 out:
1450         spin_unlock(&ci->i_ceph_lock);
1451         return 0;
1452 }
1453
1454 /*
1455  * Trim session cap count down to some max number.
1456  */
1457 static int trim_caps(struct ceph_mds_client *mdsc,
1458                      struct ceph_mds_session *session,
1459                      int max_caps)
1460 {
1461         int trim_caps = session->s_nr_caps - max_caps;
1462
1463         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1464              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1465         if (trim_caps > 0) {
1466                 session->s_trim_caps = trim_caps;
1467                 iterate_session_caps(session, trim_caps_cb, session);
1468                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1469                      session->s_mds, session->s_nr_caps, max_caps,
1470                         trim_caps - session->s_trim_caps);
1471                 session->s_trim_caps = 0;
1472         }
1473
1474         ceph_send_cap_releases(mdsc, session);
1475         return 0;
1476 }
1477
1478 static int check_capsnap_flush(struct ceph_inode_info *ci,
1479                                u64 want_snap_seq)
1480 {
1481         int ret = 1;
1482         spin_lock(&ci->i_ceph_lock);
1483         if (want_snap_seq > 0 && !list_empty(&ci->i_cap_snaps)) {
1484                 struct ceph_cap_snap *capsnap =
1485                         list_first_entry(&ci->i_cap_snaps,
1486                                          struct ceph_cap_snap, ci_item);
1487                 ret = capsnap->follows >= want_snap_seq;
1488         }
1489         spin_unlock(&ci->i_ceph_lock);
1490         return ret;
1491 }
1492
1493 static int check_caps_flush(struct ceph_mds_client *mdsc,
1494                             u64 want_flush_tid)
1495 {
1496         struct rb_node *n;
1497         struct ceph_cap_flush *cf;
1498         int ret = 1;
1499
1500         spin_lock(&mdsc->cap_dirty_lock);
1501         n = rb_first(&mdsc->cap_flush_tree);
1502         cf = n ? rb_entry(n, struct ceph_cap_flush, g_node) : NULL;
1503         if (cf && cf->tid <= want_flush_tid) {
1504                 dout("check_caps_flush still flushing tid %llu <= %llu\n",
1505                      cf->tid, want_flush_tid);
1506                 ret = 0;
1507         }
1508         spin_unlock(&mdsc->cap_dirty_lock);
1509         return ret;
1510 }
1511
1512 /*
1513  * flush all dirty inode data to disk.
1514  *
1515  * returns true if we've flushed through want_flush_tid
1516  */
1517 static void wait_caps_flush(struct ceph_mds_client *mdsc,
1518                             u64 want_flush_tid, u64 want_snap_seq)
1519 {
1520         int mds;
1521
1522         dout("check_caps_flush want %llu snap want %llu\n",
1523              want_flush_tid, want_snap_seq);
1524         mutex_lock(&mdsc->mutex);
1525         for (mds = 0; mds < mdsc->max_sessions; ) {
1526                 struct ceph_mds_session *session = mdsc->sessions[mds];
1527                 struct inode *inode = NULL;
1528
1529                 if (!session) {
1530                         mds++;
1531                         continue;
1532                 }
1533                 get_session(session);
1534                 mutex_unlock(&mdsc->mutex);
1535
1536                 mutex_lock(&session->s_mutex);
1537                 if (!list_empty(&session->s_cap_snaps_flushing)) {
1538                         struct ceph_cap_snap *capsnap =
1539                                 list_first_entry(&session->s_cap_snaps_flushing,
1540                                                  struct ceph_cap_snap,
1541                                                  flushing_item);
1542                         struct ceph_inode_info *ci = capsnap->ci;
1543                         if (!check_capsnap_flush(ci, want_snap_seq)) {
1544                                 dout("check_cap_flush still flushing snap %p "
1545                                      "follows %lld <= %lld to mds%d\n",
1546                                      &ci->vfs_inode, capsnap->follows,
1547                                      want_snap_seq, mds);
1548                                 inode = igrab(&ci->vfs_inode);
1549                         }
1550                 }
1551                 mutex_unlock(&session->s_mutex);
1552                 ceph_put_mds_session(session);
1553
1554                 if (inode) {
1555                         wait_event(mdsc->cap_flushing_wq,
1556                                    check_capsnap_flush(ceph_inode(inode),
1557                                                        want_snap_seq));
1558                         iput(inode);
1559                 } else {
1560                         mds++;
1561                 }
1562
1563                 mutex_lock(&mdsc->mutex);
1564         }
1565         mutex_unlock(&mdsc->mutex);
1566
1567         wait_event(mdsc->cap_flushing_wq,
1568                    check_caps_flush(mdsc, want_flush_tid));
1569
1570         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
1571 }
1572
1573 /*
1574  * called under s_mutex
1575  */
1576 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1577                             struct ceph_mds_session *session)
1578 {
1579         struct ceph_msg *msg = NULL;
1580         struct ceph_mds_cap_release *head;
1581         struct ceph_mds_cap_item *item;
1582         struct ceph_cap *cap;
1583         LIST_HEAD(tmp_list);
1584         int num_cap_releases;
1585
1586         spin_lock(&session->s_cap_lock);
1587 again:
1588         list_splice_init(&session->s_cap_releases, &tmp_list);
1589         num_cap_releases = session->s_num_cap_releases;
1590         session->s_num_cap_releases = 0;
1591         spin_unlock(&session->s_cap_lock);
1592
1593         while (!list_empty(&tmp_list)) {
1594                 if (!msg) {
1595                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1596                                         PAGE_CACHE_SIZE, GFP_NOFS, false);
1597                         if (!msg)
1598                                 goto out_err;
1599                         head = msg->front.iov_base;
1600                         head->num = cpu_to_le32(0);
1601                         msg->front.iov_len = sizeof(*head);
1602                 }
1603                 cap = list_first_entry(&tmp_list, struct ceph_cap,
1604                                         session_caps);
1605                 list_del(&cap->session_caps);
1606                 num_cap_releases--;
1607
1608                 head = msg->front.iov_base;
1609                 le32_add_cpu(&head->num, 1);
1610                 item = msg->front.iov_base + msg->front.iov_len;
1611                 item->ino = cpu_to_le64(cap->cap_ino);
1612                 item->cap_id = cpu_to_le64(cap->cap_id);
1613                 item->migrate_seq = cpu_to_le32(cap->mseq);
1614                 item->seq = cpu_to_le32(cap->issue_seq);
1615                 msg->front.iov_len += sizeof(*item);
1616
1617                 ceph_put_cap(mdsc, cap);
1618
1619                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1620                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1621                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1622                         ceph_con_send(&session->s_con, msg);
1623                         msg = NULL;
1624                 }
1625         }
1626
1627         BUG_ON(num_cap_releases != 0);
1628
1629         spin_lock(&session->s_cap_lock);
1630         if (!list_empty(&session->s_cap_releases))
1631                 goto again;
1632         spin_unlock(&session->s_cap_lock);
1633
1634         if (msg) {
1635                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1636                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1637                 ceph_con_send(&session->s_con, msg);
1638         }
1639         return;
1640 out_err:
1641         pr_err("send_cap_releases mds%d, failed to allocate message\n",
1642                 session->s_mds);
1643         spin_lock(&session->s_cap_lock);
1644         list_splice(&tmp_list, &session->s_cap_releases);
1645         session->s_num_cap_releases += num_cap_releases;
1646         spin_unlock(&session->s_cap_lock);
1647 }
1648
1649 /*
1650  * requests
1651  */
1652
1653 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1654                                     struct inode *dir)
1655 {
1656         struct ceph_inode_info *ci = ceph_inode(dir);
1657         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1658         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1659         size_t size = sizeof(*rinfo->dir_in) + sizeof(*rinfo->dir_dname_len) +
1660                       sizeof(*rinfo->dir_dname) + sizeof(*rinfo->dir_dlease);
1661         int order, num_entries;
1662
1663         spin_lock(&ci->i_ceph_lock);
1664         num_entries = ci->i_files + ci->i_subdirs;
1665         spin_unlock(&ci->i_ceph_lock);
1666         num_entries = max(num_entries, 1);
1667         num_entries = min(num_entries, opt->max_readdir);
1668
1669         order = get_order(size * num_entries);
1670         while (order >= 0) {
1671                 rinfo->dir_in = (void*)__get_free_pages(GFP_KERNEL |
1672                                                         __GFP_NOWARN,
1673                                                         order);
1674                 if (rinfo->dir_in)
1675                         break;
1676                 order--;
1677         }
1678         if (!rinfo->dir_in)
1679                 return -ENOMEM;
1680
1681         num_entries = (PAGE_SIZE << order) / size;
1682         num_entries = min(num_entries, opt->max_readdir);
1683
1684         rinfo->dir_buf_size = PAGE_SIZE << order;
1685         req->r_num_caps = num_entries + 1;
1686         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1687         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1688         return 0;
1689 }
1690
1691 /*
1692  * Create an mds request.
1693  */
1694 struct ceph_mds_request *
1695 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1696 {
1697         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1698
1699         if (!req)
1700                 return ERR_PTR(-ENOMEM);
1701
1702         mutex_init(&req->r_fill_mutex);
1703         req->r_mdsc = mdsc;
1704         req->r_started = jiffies;
1705         req->r_resend_mds = -1;
1706         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1707         req->r_fmode = -1;
1708         kref_init(&req->r_kref);
1709         INIT_LIST_HEAD(&req->r_wait);
1710         init_completion(&req->r_completion);
1711         init_completion(&req->r_safe_completion);
1712         INIT_LIST_HEAD(&req->r_unsafe_item);
1713
1714         req->r_stamp = CURRENT_TIME;
1715
1716         req->r_op = op;
1717         req->r_direct_mode = mode;
1718         return req;
1719 }
1720
1721 /*
1722  * return oldest (lowest) request, tid in request tree, 0 if none.
1723  *
1724  * called under mdsc->mutex.
1725  */
1726 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1727 {
1728         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1729                 return NULL;
1730         return rb_entry(rb_first(&mdsc->request_tree),
1731                         struct ceph_mds_request, r_node);
1732 }
1733
1734 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1735 {
1736         return mdsc->oldest_tid;
1737 }
1738
1739 /*
1740  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1741  * on build_path_from_dentry in fs/cifs/dir.c.
1742  *
1743  * If @stop_on_nosnap, generate path relative to the first non-snapped
1744  * inode.
1745  *
1746  * Encode hidden .snap dirs as a double /, i.e.
1747  *   foo/.snap/bar -> foo//bar
1748  */
1749 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1750                            int stop_on_nosnap)
1751 {
1752         struct dentry *temp;
1753         char *path;
1754         int len, pos;
1755         unsigned seq;
1756
1757         if (dentry == NULL)
1758                 return ERR_PTR(-EINVAL);
1759
1760 retry:
1761         len = 0;
1762         seq = read_seqbegin(&rename_lock);
1763         rcu_read_lock();
1764         for (temp = dentry; !IS_ROOT(temp);) {
1765                 struct inode *inode = d_inode(temp);
1766                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1767                         len++;  /* slash only */
1768                 else if (stop_on_nosnap && inode &&
1769                          ceph_snap(inode) == CEPH_NOSNAP)
1770                         break;
1771                 else
1772                         len += 1 + temp->d_name.len;
1773                 temp = temp->d_parent;
1774         }
1775         rcu_read_unlock();
1776         if (len)
1777                 len--;  /* no leading '/' */
1778
1779         path = kmalloc(len+1, GFP_NOFS);
1780         if (path == NULL)
1781                 return ERR_PTR(-ENOMEM);
1782         pos = len;
1783         path[pos] = 0;  /* trailing null */
1784         rcu_read_lock();
1785         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1786                 struct inode *inode;
1787
1788                 spin_lock(&temp->d_lock);
1789                 inode = d_inode(temp);
1790                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1791                         dout("build_path path+%d: %p SNAPDIR\n",
1792                              pos, temp);
1793                 } else if (stop_on_nosnap && inode &&
1794                            ceph_snap(inode) == CEPH_NOSNAP) {
1795                         spin_unlock(&temp->d_lock);
1796                         break;
1797                 } else {
1798                         pos -= temp->d_name.len;
1799                         if (pos < 0) {
1800                                 spin_unlock(&temp->d_lock);
1801                                 break;
1802                         }
1803                         strncpy(path + pos, temp->d_name.name,
1804                                 temp->d_name.len);
1805                 }
1806                 spin_unlock(&temp->d_lock);
1807                 if (pos)
1808                         path[--pos] = '/';
1809                 temp = temp->d_parent;
1810         }
1811         rcu_read_unlock();
1812         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1813                 pr_err("build_path did not end path lookup where "
1814                        "expected, namelen is %d, pos is %d\n", len, pos);
1815                 /* presumably this is only possible if racing with a
1816                    rename of one of the parent directories (we can not
1817                    lock the dentries above us to prevent this, but
1818                    retrying should be harmless) */
1819                 kfree(path);
1820                 goto retry;
1821         }
1822
1823         *base = ceph_ino(d_inode(temp));
1824         *plen = len;
1825         dout("build_path on %p %d built %llx '%.*s'\n",
1826              dentry, d_count(dentry), *base, len, path);
1827         return path;
1828 }
1829
1830 static int build_dentry_path(struct dentry *dentry,
1831                              const char **ppath, int *ppathlen, u64 *pino,
1832                              int *pfreepath)
1833 {
1834         char *path;
1835
1836         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP) {
1837                 *pino = ceph_ino(d_inode(dentry->d_parent));
1838                 *ppath = dentry->d_name.name;
1839                 *ppathlen = dentry->d_name.len;
1840                 return 0;
1841         }
1842         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1843         if (IS_ERR(path))
1844                 return PTR_ERR(path);
1845         *ppath = path;
1846         *pfreepath = 1;
1847         return 0;
1848 }
1849
1850 static int build_inode_path(struct inode *inode,
1851                             const char **ppath, int *ppathlen, u64 *pino,
1852                             int *pfreepath)
1853 {
1854         struct dentry *dentry;
1855         char *path;
1856
1857         if (ceph_snap(inode) == CEPH_NOSNAP) {
1858                 *pino = ceph_ino(inode);
1859                 *ppathlen = 0;
1860                 return 0;
1861         }
1862         dentry = d_find_alias(inode);
1863         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1864         dput(dentry);
1865         if (IS_ERR(path))
1866                 return PTR_ERR(path);
1867         *ppath = path;
1868         *pfreepath = 1;
1869         return 0;
1870 }
1871
1872 /*
1873  * request arguments may be specified via an inode *, a dentry *, or
1874  * an explicit ino+path.
1875  */
1876 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1877                                   const char *rpath, u64 rino,
1878                                   const char **ppath, int *pathlen,
1879                                   u64 *ino, int *freepath)
1880 {
1881         int r = 0;
1882
1883         if (rinode) {
1884                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1885                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1886                      ceph_snap(rinode));
1887         } else if (rdentry) {
1888                 r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1889                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1890                      *ppath);
1891         } else if (rpath || rino) {
1892                 *ino = rino;
1893                 *ppath = rpath;
1894                 *pathlen = rpath ? strlen(rpath) : 0;
1895                 dout(" path %.*s\n", *pathlen, rpath);
1896         }
1897
1898         return r;
1899 }
1900
1901 /*
1902  * called under mdsc->mutex
1903  */
1904 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1905                                                struct ceph_mds_request *req,
1906                                                int mds, bool drop_cap_releases)
1907 {
1908         struct ceph_msg *msg;
1909         struct ceph_mds_request_head *head;
1910         const char *path1 = NULL;
1911         const char *path2 = NULL;
1912         u64 ino1 = 0, ino2 = 0;
1913         int pathlen1 = 0, pathlen2 = 0;
1914         int freepath1 = 0, freepath2 = 0;
1915         int len;
1916         u16 releases;
1917         void *p, *end;
1918         int ret;
1919
1920         ret = set_request_path_attr(req->r_inode, req->r_dentry,
1921                               req->r_path1, req->r_ino1.ino,
1922                               &path1, &pathlen1, &ino1, &freepath1);
1923         if (ret < 0) {
1924                 msg = ERR_PTR(ret);
1925                 goto out;
1926         }
1927
1928         ret = set_request_path_attr(NULL, req->r_old_dentry,
1929                               req->r_path2, req->r_ino2.ino,
1930                               &path2, &pathlen2, &ino2, &freepath2);
1931         if (ret < 0) {
1932                 msg = ERR_PTR(ret);
1933                 goto out_free1;
1934         }
1935
1936         len = sizeof(*head) +
1937                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1938                 sizeof(struct timespec);
1939
1940         /* calculate (max) length for cap releases */
1941         len += sizeof(struct ceph_mds_request_release) *
1942                 (!!req->r_inode_drop + !!req->r_dentry_drop +
1943                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1944         if (req->r_dentry_drop)
1945                 len += req->r_dentry->d_name.len;
1946         if (req->r_old_dentry_drop)
1947                 len += req->r_old_dentry->d_name.len;
1948
1949         msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1950         if (!msg) {
1951                 msg = ERR_PTR(-ENOMEM);
1952                 goto out_free2;
1953         }
1954
1955         msg->hdr.version = cpu_to_le16(2);
1956         msg->hdr.tid = cpu_to_le64(req->r_tid);
1957
1958         head = msg->front.iov_base;
1959         p = msg->front.iov_base + sizeof(*head);
1960         end = msg->front.iov_base + msg->front.iov_len;
1961
1962         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1963         head->op = cpu_to_le32(req->r_op);
1964         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1965         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1966         head->args = req->r_args;
1967
1968         ceph_encode_filepath(&p, end, ino1, path1);
1969         ceph_encode_filepath(&p, end, ino2, path2);
1970
1971         /* make note of release offset, in case we need to replay */
1972         req->r_request_release_offset = p - msg->front.iov_base;
1973
1974         /* cap releases */
1975         releases = 0;
1976         if (req->r_inode_drop)
1977                 releases += ceph_encode_inode_release(&p,
1978                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
1979                       mds, req->r_inode_drop, req->r_inode_unless, 0);
1980         if (req->r_dentry_drop)
1981                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
1982                        mds, req->r_dentry_drop, req->r_dentry_unless);
1983         if (req->r_old_dentry_drop)
1984                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1985                        mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1986         if (req->r_old_inode_drop)
1987                 releases += ceph_encode_inode_release(&p,
1988                       d_inode(req->r_old_dentry),
1989                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1990
1991         if (drop_cap_releases) {
1992                 releases = 0;
1993                 p = msg->front.iov_base + req->r_request_release_offset;
1994         }
1995
1996         head->num_releases = cpu_to_le16(releases);
1997
1998         /* time stamp */
1999         {
2000                 struct ceph_timespec ts;
2001                 ceph_encode_timespec(&ts, &req->r_stamp);
2002                 ceph_encode_copy(&p, &ts, sizeof(ts));
2003         }
2004
2005         BUG_ON(p > end);
2006         msg->front.iov_len = p - msg->front.iov_base;
2007         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2008
2009         if (req->r_pagelist) {
2010                 struct ceph_pagelist *pagelist = req->r_pagelist;
2011                 atomic_inc(&pagelist->refcnt);
2012                 ceph_msg_data_add_pagelist(msg, pagelist);
2013                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2014         } else {
2015                 msg->hdr.data_len = 0;
2016         }
2017
2018         msg->hdr.data_off = cpu_to_le16(0);
2019
2020 out_free2:
2021         if (freepath2)
2022                 kfree((char *)path2);
2023 out_free1:
2024         if (freepath1)
2025                 kfree((char *)path1);
2026 out:
2027         return msg;
2028 }
2029
2030 /*
2031  * called under mdsc->mutex if error, under no mutex if
2032  * success.
2033  */
2034 static void complete_request(struct ceph_mds_client *mdsc,
2035                              struct ceph_mds_request *req)
2036 {
2037         if (req->r_callback)
2038                 req->r_callback(mdsc, req);
2039         else
2040                 complete_all(&req->r_completion);
2041 }
2042
2043 /*
2044  * called under mdsc->mutex
2045  */
2046 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2047                                   struct ceph_mds_request *req,
2048                                   int mds, bool drop_cap_releases)
2049 {
2050         struct ceph_mds_request_head *rhead;
2051         struct ceph_msg *msg;
2052         int flags = 0;
2053
2054         req->r_attempts++;
2055         if (req->r_inode) {
2056                 struct ceph_cap *cap =
2057                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2058
2059                 if (cap)
2060                         req->r_sent_on_mseq = cap->mseq;
2061                 else
2062                         req->r_sent_on_mseq = -1;
2063         }
2064         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2065              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2066
2067         if (req->r_got_unsafe) {
2068                 void *p;
2069                 /*
2070                  * Replay.  Do not regenerate message (and rebuild
2071                  * paths, etc.); just use the original message.
2072                  * Rebuilding paths will break for renames because
2073                  * d_move mangles the src name.
2074                  */
2075                 msg = req->r_request;
2076                 rhead = msg->front.iov_base;
2077
2078                 flags = le32_to_cpu(rhead->flags);
2079                 flags |= CEPH_MDS_FLAG_REPLAY;
2080                 rhead->flags = cpu_to_le32(flags);
2081
2082                 if (req->r_target_inode)
2083                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2084
2085                 rhead->num_retry = req->r_attempts - 1;
2086
2087                 /* remove cap/dentry releases from message */
2088                 rhead->num_releases = 0;
2089
2090                 /* time stamp */
2091                 p = msg->front.iov_base + req->r_request_release_offset;
2092                 {
2093                         struct ceph_timespec ts;
2094                         ceph_encode_timespec(&ts, &req->r_stamp);
2095                         ceph_encode_copy(&p, &ts, sizeof(ts));
2096                 }
2097
2098                 msg->front.iov_len = p - msg->front.iov_base;
2099                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2100                 return 0;
2101         }
2102
2103         if (req->r_request) {
2104                 ceph_msg_put(req->r_request);
2105                 req->r_request = NULL;
2106         }
2107         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2108         if (IS_ERR(msg)) {
2109                 req->r_err = PTR_ERR(msg);
2110                 complete_request(mdsc, req);
2111                 return PTR_ERR(msg);
2112         }
2113         req->r_request = msg;
2114
2115         rhead = msg->front.iov_base;
2116         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2117         if (req->r_got_unsafe)
2118                 flags |= CEPH_MDS_FLAG_REPLAY;
2119         if (req->r_locked_dir)
2120                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2121         rhead->flags = cpu_to_le32(flags);
2122         rhead->num_fwd = req->r_num_fwd;
2123         rhead->num_retry = req->r_attempts - 1;
2124         rhead->ino = 0;
2125
2126         dout(" r_locked_dir = %p\n", req->r_locked_dir);
2127         return 0;
2128 }
2129
2130 /*
2131  * send request, or put it on the appropriate wait list.
2132  */
2133 static int __do_request(struct ceph_mds_client *mdsc,
2134                         struct ceph_mds_request *req)
2135 {
2136         struct ceph_mds_session *session = NULL;
2137         int mds = -1;
2138         int err = -EAGAIN;
2139
2140         if (req->r_err || req->r_got_result) {
2141                 if (req->r_aborted)
2142                         __unregister_request(mdsc, req);
2143                 goto out;
2144         }
2145
2146         if (req->r_timeout &&
2147             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2148                 dout("do_request timed out\n");
2149                 err = -EIO;
2150                 goto finish;
2151         }
2152
2153         put_request_session(req);
2154
2155         mds = __choose_mds(mdsc, req);
2156         if (mds < 0 ||
2157             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2158                 dout("do_request no mds or not active, waiting for map\n");
2159                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2160                 goto out;
2161         }
2162
2163         /* get, open session */
2164         session = __ceph_lookup_mds_session(mdsc, mds);
2165         if (!session) {
2166                 session = register_session(mdsc, mds);
2167                 if (IS_ERR(session)) {
2168                         err = PTR_ERR(session);
2169                         goto finish;
2170                 }
2171         }
2172         req->r_session = get_session(session);
2173
2174         dout("do_request mds%d session %p state %s\n", mds, session,
2175              ceph_session_state_name(session->s_state));
2176         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2177             session->s_state != CEPH_MDS_SESSION_HUNG) {
2178                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2179                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2180                         __open_session(mdsc, session);
2181                 list_add(&req->r_wait, &session->s_waiting);
2182                 goto out_session;
2183         }
2184
2185         /* send request */
2186         req->r_resend_mds = -1;   /* forget any previous mds hint */
2187
2188         if (req->r_request_started == 0)   /* note request start time */
2189                 req->r_request_started = jiffies;
2190
2191         err = __prepare_send_request(mdsc, req, mds, false);
2192         if (!err) {
2193                 ceph_msg_get(req->r_request);
2194                 ceph_con_send(&session->s_con, req->r_request);
2195         }
2196
2197 out_session:
2198         ceph_put_mds_session(session);
2199 out:
2200         return err;
2201
2202 finish:
2203         req->r_err = err;
2204         complete_request(mdsc, req);
2205         goto out;
2206 }
2207
2208 /*
2209  * called under mdsc->mutex
2210  */
2211 static void __wake_requests(struct ceph_mds_client *mdsc,
2212                             struct list_head *head)
2213 {
2214         struct ceph_mds_request *req;
2215         LIST_HEAD(tmp_list);
2216
2217         list_splice_init(head, &tmp_list);
2218
2219         while (!list_empty(&tmp_list)) {
2220                 req = list_entry(tmp_list.next,
2221                                  struct ceph_mds_request, r_wait);
2222                 list_del_init(&req->r_wait);
2223                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2224                 __do_request(mdsc, req);
2225         }
2226 }
2227
2228 /*
2229  * Wake up threads with requests pending for @mds, so that they can
2230  * resubmit their requests to a possibly different mds.
2231  */
2232 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2233 {
2234         struct ceph_mds_request *req;
2235         struct rb_node *p = rb_first(&mdsc->request_tree);
2236
2237         dout("kick_requests mds%d\n", mds);
2238         while (p) {
2239                 req = rb_entry(p, struct ceph_mds_request, r_node);
2240                 p = rb_next(p);
2241                 if (req->r_got_unsafe)
2242                         continue;
2243                 if (req->r_attempts > 0)
2244                         continue; /* only new requests */
2245                 if (req->r_session &&
2246                     req->r_session->s_mds == mds) {
2247                         dout(" kicking tid %llu\n", req->r_tid);
2248                         list_del_init(&req->r_wait);
2249                         __do_request(mdsc, req);
2250                 }
2251         }
2252 }
2253
2254 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2255                               struct ceph_mds_request *req)
2256 {
2257         dout("submit_request on %p\n", req);
2258         mutex_lock(&mdsc->mutex);
2259         __register_request(mdsc, req, NULL);
2260         __do_request(mdsc, req);
2261         mutex_unlock(&mdsc->mutex);
2262 }
2263
2264 /*
2265  * Synchrously perform an mds request.  Take care of all of the
2266  * session setup, forwarding, retry details.
2267  */
2268 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2269                          struct inode *dir,
2270                          struct ceph_mds_request *req)
2271 {
2272         int err;
2273
2274         dout("do_request on %p\n", req);
2275
2276         /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2277         if (req->r_inode)
2278                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2279         if (req->r_locked_dir)
2280                 ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2281         if (req->r_old_dentry_dir)
2282                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2283                                   CEPH_CAP_PIN);
2284
2285         /* issue */
2286         mutex_lock(&mdsc->mutex);
2287         __register_request(mdsc, req, dir);
2288         __do_request(mdsc, req);
2289
2290         if (req->r_err) {
2291                 err = req->r_err;
2292                 __unregister_request(mdsc, req);
2293                 dout("do_request early error %d\n", err);
2294                 goto out;
2295         }
2296
2297         /* wait */
2298         mutex_unlock(&mdsc->mutex);
2299         dout("do_request waiting\n");
2300         if (!req->r_timeout && req->r_wait_for_completion) {
2301                 err = req->r_wait_for_completion(mdsc, req);
2302         } else {
2303                 long timeleft = wait_for_completion_killable_timeout(
2304                                         &req->r_completion,
2305                                         ceph_timeout_jiffies(req->r_timeout));
2306                 if (timeleft > 0)
2307                         err = 0;
2308                 else if (!timeleft)
2309                         err = -EIO;  /* timed out */
2310                 else
2311                         err = timeleft;  /* killed */
2312         }
2313         dout("do_request waited, got %d\n", err);
2314         mutex_lock(&mdsc->mutex);
2315
2316         /* only abort if we didn't race with a real reply */
2317         if (req->r_got_result) {
2318                 err = le32_to_cpu(req->r_reply_info.head->result);
2319         } else if (err < 0) {
2320                 dout("aborted request %lld with %d\n", req->r_tid, err);
2321
2322                 /*
2323                  * ensure we aren't running concurrently with
2324                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2325                  * rely on locks (dir mutex) held by our caller.
2326                  */
2327                 mutex_lock(&req->r_fill_mutex);
2328                 req->r_err = err;
2329                 req->r_aborted = true;
2330                 mutex_unlock(&req->r_fill_mutex);
2331
2332                 if (req->r_locked_dir &&
2333                     (req->r_op & CEPH_MDS_OP_WRITE))
2334                         ceph_invalidate_dir_request(req);
2335         } else {
2336                 err = req->r_err;
2337         }
2338
2339 out:
2340         mutex_unlock(&mdsc->mutex);
2341         dout("do_request %p done, result %d\n", req, err);
2342         return err;
2343 }
2344
2345 /*
2346  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2347  * namespace request.
2348  */
2349 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2350 {
2351         struct inode *inode = req->r_locked_dir;
2352
2353         dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2354
2355         ceph_dir_clear_complete(inode);
2356         if (req->r_dentry)
2357                 ceph_invalidate_dentry_lease(req->r_dentry);
2358         if (req->r_old_dentry)
2359                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2360 }
2361
2362 /*
2363  * Handle mds reply.
2364  *
2365  * We take the session mutex and parse and process the reply immediately.
2366  * This preserves the logical ordering of replies, capabilities, etc., sent
2367  * by the MDS as they are applied to our local cache.
2368  */
2369 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2370 {
2371         struct ceph_mds_client *mdsc = session->s_mdsc;
2372         struct ceph_mds_request *req;
2373         struct ceph_mds_reply_head *head = msg->front.iov_base;
2374         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2375         struct ceph_snap_realm *realm;
2376         u64 tid;
2377         int err, result;
2378         int mds = session->s_mds;
2379
2380         if (msg->front.iov_len < sizeof(*head)) {
2381                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2382                 ceph_msg_dump(msg);
2383                 return;
2384         }
2385
2386         /* get request, session */
2387         tid = le64_to_cpu(msg->hdr.tid);
2388         mutex_lock(&mdsc->mutex);
2389         req = __lookup_request(mdsc, tid);
2390         if (!req) {
2391                 dout("handle_reply on unknown tid %llu\n", tid);
2392                 mutex_unlock(&mdsc->mutex);
2393                 return;
2394         }
2395         dout("handle_reply %p\n", req);
2396
2397         /* correct session? */
2398         if (req->r_session != session) {
2399                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2400                        " not mds%d\n", tid, session->s_mds,
2401                        req->r_session ? req->r_session->s_mds : -1);
2402                 mutex_unlock(&mdsc->mutex);
2403                 goto out;
2404         }
2405
2406         /* dup? */
2407         if ((req->r_got_unsafe && !head->safe) ||
2408             (req->r_got_safe && head->safe)) {
2409                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2410                            head->safe ? "safe" : "unsafe", tid, mds);
2411                 mutex_unlock(&mdsc->mutex);
2412                 goto out;
2413         }
2414         if (req->r_got_safe && !head->safe) {
2415                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2416                            tid, mds);
2417                 mutex_unlock(&mdsc->mutex);
2418                 goto out;
2419         }
2420
2421         result = le32_to_cpu(head->result);
2422
2423         /*
2424          * Handle an ESTALE
2425          * if we're not talking to the authority, send to them
2426          * if the authority has changed while we weren't looking,
2427          * send to new authority
2428          * Otherwise we just have to return an ESTALE
2429          */
2430         if (result == -ESTALE) {
2431                 dout("got ESTALE on request %llu", req->r_tid);
2432                 req->r_resend_mds = -1;
2433                 if (req->r_direct_mode != USE_AUTH_MDS) {
2434                         dout("not using auth, setting for that now");
2435                         req->r_direct_mode = USE_AUTH_MDS;
2436                         __do_request(mdsc, req);
2437                         mutex_unlock(&mdsc->mutex);
2438                         goto out;
2439                 } else  {
2440                         int mds = __choose_mds(mdsc, req);
2441                         if (mds >= 0 && mds != req->r_session->s_mds) {
2442                                 dout("but auth changed, so resending");
2443                                 __do_request(mdsc, req);
2444                                 mutex_unlock(&mdsc->mutex);
2445                                 goto out;
2446                         }
2447                 }
2448                 dout("have to return ESTALE on request %llu", req->r_tid);
2449         }
2450
2451
2452         if (head->safe) {
2453                 req->r_got_safe = true;
2454                 __unregister_request(mdsc, req);
2455
2456                 if (req->r_got_unsafe) {
2457                         /*
2458                          * We already handled the unsafe response, now do the
2459                          * cleanup.  No need to examine the response; the MDS
2460                          * doesn't include any result info in the safe
2461                          * response.  And even if it did, there is nothing
2462                          * useful we could do with a revised return value.
2463                          */
2464                         dout("got safe reply %llu, mds%d\n", tid, mds);
2465                         list_del_init(&req->r_unsafe_item);
2466
2467                         /* last unsafe request during umount? */
2468                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2469                                 complete_all(&mdsc->safe_umount_waiters);
2470                         mutex_unlock(&mdsc->mutex);
2471                         goto out;
2472                 }
2473         } else {
2474                 req->r_got_unsafe = true;
2475                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2476         }
2477
2478         dout("handle_reply tid %lld result %d\n", tid, result);
2479         rinfo = &req->r_reply_info;
2480         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2481         mutex_unlock(&mdsc->mutex);
2482
2483         mutex_lock(&session->s_mutex);
2484         if (err < 0) {
2485                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2486                 ceph_msg_dump(msg);
2487                 goto out_err;
2488         }
2489
2490         /* snap trace */
2491         realm = NULL;
2492         if (rinfo->snapblob_len) {
2493                 down_write(&mdsc->snap_rwsem);
2494                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2495                                 rinfo->snapblob + rinfo->snapblob_len,
2496                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2497                                 &realm);
2498                 downgrade_write(&mdsc->snap_rwsem);
2499         } else {
2500                 down_read(&mdsc->snap_rwsem);
2501         }
2502
2503         /* insert trace into our cache */
2504         mutex_lock(&req->r_fill_mutex);
2505         err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2506         if (err == 0) {
2507                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2508                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2509                         ceph_readdir_prepopulate(req, req->r_session);
2510                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2511         }
2512         mutex_unlock(&req->r_fill_mutex);
2513
2514         up_read(&mdsc->snap_rwsem);
2515         if (realm)
2516                 ceph_put_snap_realm(mdsc, realm);
2517 out_err:
2518         mutex_lock(&mdsc->mutex);
2519         if (!req->r_aborted) {
2520                 if (err) {
2521                         req->r_err = err;
2522                 } else {
2523                         req->r_reply = msg;
2524                         ceph_msg_get(msg);
2525                         req->r_got_result = true;
2526                 }
2527         } else {
2528                 dout("reply arrived after request %lld was aborted\n", tid);
2529         }
2530         mutex_unlock(&mdsc->mutex);
2531
2532         mutex_unlock(&session->s_mutex);
2533
2534         /* kick calling process */
2535         complete_request(mdsc, req);
2536 out:
2537         ceph_mdsc_put_request(req);
2538         return;
2539 }
2540
2541
2542
2543 /*
2544  * handle mds notification that our request has been forwarded.
2545  */
2546 static void handle_forward(struct ceph_mds_client *mdsc,
2547                            struct ceph_mds_session *session,
2548                            struct ceph_msg *msg)
2549 {
2550         struct ceph_mds_request *req;
2551         u64 tid = le64_to_cpu(msg->hdr.tid);
2552         u32 next_mds;
2553         u32 fwd_seq;
2554         int err = -EINVAL;
2555         void *p = msg->front.iov_base;
2556         void *end = p + msg->front.iov_len;
2557
2558         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2559         next_mds = ceph_decode_32(&p);
2560         fwd_seq = ceph_decode_32(&p);
2561
2562         mutex_lock(&mdsc->mutex);
2563         req = __lookup_request(mdsc, tid);
2564         if (!req) {
2565                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2566                 goto out;  /* dup reply? */
2567         }
2568
2569         if (req->r_aborted) {
2570                 dout("forward tid %llu aborted, unregistering\n", tid);
2571                 __unregister_request(mdsc, req);
2572         } else if (fwd_seq <= req->r_num_fwd) {
2573                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2574                      tid, next_mds, req->r_num_fwd, fwd_seq);
2575         } else {
2576                 /* resend. forward race not possible; mds would drop */
2577                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2578                 BUG_ON(req->r_err);
2579                 BUG_ON(req->r_got_result);
2580                 req->r_attempts = 0;
2581                 req->r_num_fwd = fwd_seq;
2582                 req->r_resend_mds = next_mds;
2583                 put_request_session(req);
2584                 __do_request(mdsc, req);
2585         }
2586         ceph_mdsc_put_request(req);
2587 out:
2588         mutex_unlock(&mdsc->mutex);
2589         return;
2590
2591 bad:
2592         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2593 }
2594
2595 /*
2596  * handle a mds session control message
2597  */
2598 static void handle_session(struct ceph_mds_session *session,
2599                            struct ceph_msg *msg)
2600 {
2601         struct ceph_mds_client *mdsc = session->s_mdsc;
2602         u32 op;
2603         u64 seq;
2604         int mds = session->s_mds;
2605         struct ceph_mds_session_head *h = msg->front.iov_base;
2606         int wake = 0;
2607
2608         /* decode */
2609         if (msg->front.iov_len != sizeof(*h))
2610                 goto bad;
2611         op = le32_to_cpu(h->op);
2612         seq = le64_to_cpu(h->seq);
2613
2614         mutex_lock(&mdsc->mutex);
2615         if (op == CEPH_SESSION_CLOSE)
2616                 __unregister_session(mdsc, session);
2617         /* FIXME: this ttl calculation is generous */
2618         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2619         mutex_unlock(&mdsc->mutex);
2620
2621         mutex_lock(&session->s_mutex);
2622
2623         dout("handle_session mds%d %s %p state %s seq %llu\n",
2624              mds, ceph_session_op_name(op), session,
2625              ceph_session_state_name(session->s_state), seq);
2626
2627         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2628                 session->s_state = CEPH_MDS_SESSION_OPEN;
2629                 pr_info("mds%d came back\n", session->s_mds);
2630         }
2631
2632         switch (op) {
2633         case CEPH_SESSION_OPEN:
2634                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2635                         pr_info("mds%d reconnect success\n", session->s_mds);
2636                 session->s_state = CEPH_MDS_SESSION_OPEN;
2637                 renewed_caps(mdsc, session, 0);
2638                 wake = 1;
2639                 if (mdsc->stopping)
2640                         __close_session(mdsc, session);
2641                 break;
2642
2643         case CEPH_SESSION_RENEWCAPS:
2644                 if (session->s_renew_seq == seq)
2645                         renewed_caps(mdsc, session, 1);
2646                 break;
2647
2648         case CEPH_SESSION_CLOSE:
2649                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2650                         pr_info("mds%d reconnect denied\n", session->s_mds);
2651                 cleanup_session_requests(mdsc, session);
2652                 remove_session_caps(session);
2653                 wake = 2; /* for good measure */
2654                 wake_up_all(&mdsc->session_close_wq);
2655                 break;
2656
2657         case CEPH_SESSION_STALE:
2658                 pr_info("mds%d caps went stale, renewing\n",
2659                         session->s_mds);
2660                 spin_lock(&session->s_gen_ttl_lock);
2661                 session->s_cap_gen++;
2662                 session->s_cap_ttl = jiffies - 1;
2663                 spin_unlock(&session->s_gen_ttl_lock);
2664                 send_renew_caps(mdsc, session);
2665                 break;
2666
2667         case CEPH_SESSION_RECALL_STATE:
2668                 trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2669                 break;
2670
2671         case CEPH_SESSION_FLUSHMSG:
2672                 send_flushmsg_ack(mdsc, session, seq);
2673                 break;
2674
2675         case CEPH_SESSION_FORCE_RO:
2676                 dout("force_session_readonly %p\n", session);
2677                 spin_lock(&session->s_cap_lock);
2678                 session->s_readonly = true;
2679                 spin_unlock(&session->s_cap_lock);
2680                 wake_up_session_caps(session, 0);
2681                 break;
2682
2683         default:
2684                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2685                 WARN_ON(1);
2686         }
2687
2688         mutex_unlock(&session->s_mutex);
2689         if (wake) {
2690                 mutex_lock(&mdsc->mutex);
2691                 __wake_requests(mdsc, &session->s_waiting);
2692                 if (wake == 2)
2693                         kick_requests(mdsc, mds);
2694                 mutex_unlock(&mdsc->mutex);
2695         }
2696         return;
2697
2698 bad:
2699         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2700                (int)msg->front.iov_len);
2701         ceph_msg_dump(msg);
2702         return;
2703 }
2704
2705
2706 /*
2707  * called under session->mutex.
2708  */
2709 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2710                                    struct ceph_mds_session *session)
2711 {
2712         struct ceph_mds_request *req, *nreq;
2713         struct rb_node *p;
2714         int err;
2715
2716         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2717
2718         mutex_lock(&mdsc->mutex);
2719         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2720                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
2721                 if (!err) {
2722                         ceph_msg_get(req->r_request);
2723                         ceph_con_send(&session->s_con, req->r_request);
2724                 }
2725         }
2726
2727         /*
2728          * also re-send old requests when MDS enters reconnect stage. So that MDS
2729          * can process completed request in clientreplay stage.
2730          */
2731         p = rb_first(&mdsc->request_tree);
2732         while (p) {
2733                 req = rb_entry(p, struct ceph_mds_request, r_node);
2734                 p = rb_next(p);
2735                 if (req->r_got_unsafe)
2736                         continue;
2737                 if (req->r_attempts == 0)
2738                         continue; /* only old requests */
2739                 if (req->r_session &&
2740                     req->r_session->s_mds == session->s_mds) {
2741                         err = __prepare_send_request(mdsc, req,
2742                                                      session->s_mds, true);
2743                         if (!err) {
2744                                 ceph_msg_get(req->r_request);
2745                                 ceph_con_send(&session->s_con, req->r_request);
2746                         }
2747                 }
2748         }
2749         mutex_unlock(&mdsc->mutex);
2750 }
2751
2752 /*
2753  * Encode information about a cap for a reconnect with the MDS.
2754  */
2755 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2756                           void *arg)
2757 {
2758         union {
2759                 struct ceph_mds_cap_reconnect v2;
2760                 struct ceph_mds_cap_reconnect_v1 v1;
2761         } rec;
2762         size_t reclen;
2763         struct ceph_inode_info *ci;
2764         struct ceph_reconnect_state *recon_state = arg;
2765         struct ceph_pagelist *pagelist = recon_state->pagelist;
2766         char *path;
2767         int pathlen, err;
2768         u64 pathbase;
2769         struct dentry *dentry;
2770
2771         ci = cap->ci;
2772
2773         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2774              inode, ceph_vinop(inode), cap, cap->cap_id,
2775              ceph_cap_string(cap->issued));
2776         err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2777         if (err)
2778                 return err;
2779
2780         dentry = d_find_alias(inode);
2781         if (dentry) {
2782                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2783                 if (IS_ERR(path)) {
2784                         err = PTR_ERR(path);
2785                         goto out_dput;
2786                 }
2787         } else {
2788                 path = NULL;
2789                 pathlen = 0;
2790         }
2791         err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2792         if (err)
2793                 goto out_free;
2794
2795         spin_lock(&ci->i_ceph_lock);
2796         cap->seq = 0;        /* reset cap seq */
2797         cap->issue_seq = 0;  /* and issue_seq */
2798         cap->mseq = 0;       /* and migrate_seq */
2799         cap->cap_gen = cap->session->s_cap_gen;
2800
2801         if (recon_state->flock) {
2802                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2803                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2804                 rec.v2.issued = cpu_to_le32(cap->issued);
2805                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2806                 rec.v2.pathbase = cpu_to_le64(pathbase);
2807                 rec.v2.flock_len = 0;
2808                 reclen = sizeof(rec.v2);
2809         } else {
2810                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2811                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2812                 rec.v1.issued = cpu_to_le32(cap->issued);
2813                 rec.v1.size = cpu_to_le64(inode->i_size);
2814                 ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2815                 ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2816                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2817                 rec.v1.pathbase = cpu_to_le64(pathbase);
2818                 reclen = sizeof(rec.v1);
2819         }
2820         spin_unlock(&ci->i_ceph_lock);
2821
2822         if (recon_state->flock) {
2823                 int num_fcntl_locks, num_flock_locks;
2824                 struct ceph_filelock *flocks;
2825
2826 encode_again:
2827                 ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2828                 flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2829                                  sizeof(struct ceph_filelock), GFP_NOFS);
2830                 if (!flocks) {
2831                         err = -ENOMEM;
2832                         goto out_free;
2833                 }
2834                 err = ceph_encode_locks_to_buffer(inode, flocks,
2835                                                   num_fcntl_locks,
2836                                                   num_flock_locks);
2837                 if (err) {
2838                         kfree(flocks);
2839                         if (err == -ENOSPC)
2840                                 goto encode_again;
2841                         goto out_free;
2842                 }
2843                 /*
2844                  * number of encoded locks is stable, so copy to pagelist
2845                  */
2846                 rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2847                                     (num_fcntl_locks+num_flock_locks) *
2848                                     sizeof(struct ceph_filelock));
2849                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2850                 if (!err)
2851                         err = ceph_locks_to_pagelist(flocks, pagelist,
2852                                                      num_fcntl_locks,
2853                                                      num_flock_locks);
2854                 kfree(flocks);
2855         } else {
2856                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2857         }
2858
2859         recon_state->nr_caps++;
2860 out_free:
2861         kfree(path);
2862 out_dput:
2863         dput(dentry);
2864         return err;
2865 }
2866
2867
2868 /*
2869  * If an MDS fails and recovers, clients need to reconnect in order to
2870  * reestablish shared state.  This includes all caps issued through
2871  * this session _and_ the snap_realm hierarchy.  Because it's not
2872  * clear which snap realms the mds cares about, we send everything we
2873  * know about.. that ensures we'll then get any new info the
2874  * recovering MDS might have.
2875  *
2876  * This is a relatively heavyweight operation, but it's rare.
2877  *
2878  * called with mdsc->mutex held.
2879  */
2880 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2881                                struct ceph_mds_session *session)
2882 {
2883         struct ceph_msg *reply;
2884         struct rb_node *p;
2885         int mds = session->s_mds;
2886         int err = -ENOMEM;
2887         int s_nr_caps;
2888         struct ceph_pagelist *pagelist;
2889         struct ceph_reconnect_state recon_state;
2890
2891         pr_info("mds%d reconnect start\n", mds);
2892
2893         pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2894         if (!pagelist)
2895                 goto fail_nopagelist;
2896         ceph_pagelist_init(pagelist);
2897
2898         reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2899         if (!reply)
2900                 goto fail_nomsg;
2901
2902         mutex_lock(&session->s_mutex);
2903         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2904         session->s_seq = 0;
2905
2906         dout("session %p state %s\n", session,
2907              ceph_session_state_name(session->s_state));
2908
2909         spin_lock(&session->s_gen_ttl_lock);
2910         session->s_cap_gen++;
2911         spin_unlock(&session->s_gen_ttl_lock);
2912
2913         spin_lock(&session->s_cap_lock);
2914         /* don't know if session is readonly */
2915         session->s_readonly = 0;
2916         /*
2917          * notify __ceph_remove_cap() that we are composing cap reconnect.
2918          * If a cap get released before being added to the cap reconnect,
2919          * __ceph_remove_cap() should skip queuing cap release.
2920          */
2921         session->s_cap_reconnect = 1;
2922         /* drop old cap expires; we're about to reestablish that state */
2923         cleanup_cap_releases(mdsc, session);
2924
2925         /* trim unused caps to reduce MDS's cache rejoin time */
2926         if (mdsc->fsc->sb->s_root)
2927                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
2928
2929         ceph_con_close(&session->s_con);
2930         ceph_con_open(&session->s_con,
2931                       CEPH_ENTITY_TYPE_MDS, mds,
2932                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2933
2934         /* replay unsafe requests */
2935         replay_unsafe_requests(mdsc, session);
2936
2937         down_read(&mdsc->snap_rwsem);
2938
2939         /* traverse this session's caps */
2940         s_nr_caps = session->s_nr_caps;
2941         err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2942         if (err)
2943                 goto fail;
2944
2945         recon_state.nr_caps = 0;
2946         recon_state.pagelist = pagelist;
2947         recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2948         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2949         if (err < 0)
2950                 goto fail;
2951
2952         spin_lock(&session->s_cap_lock);
2953         session->s_cap_reconnect = 0;
2954         spin_unlock(&session->s_cap_lock);
2955
2956         /*
2957          * snaprealms.  we provide mds with the ino, seq (version), and
2958          * parent for all of our realms.  If the mds has any newer info,
2959          * it will tell us.
2960          */
2961         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2962                 struct ceph_snap_realm *realm =
2963                         rb_entry(p, struct ceph_snap_realm, node);
2964                 struct ceph_mds_snaprealm_reconnect sr_rec;
2965
2966                 dout(" adding snap realm %llx seq %lld parent %llx\n",
2967                      realm->ino, realm->seq, realm->parent_ino);
2968                 sr_rec.ino = cpu_to_le64(realm->ino);
2969                 sr_rec.seq = cpu_to_le64(realm->seq);
2970                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
2971                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2972                 if (err)
2973                         goto fail;
2974         }
2975
2976         if (recon_state.flock)
2977                 reply->hdr.version = cpu_to_le16(2);
2978
2979         /* raced with cap release? */
2980         if (s_nr_caps != recon_state.nr_caps) {
2981                 struct page *page = list_first_entry(&pagelist->head,
2982                                                      struct page, lru);
2983                 __le32 *addr = kmap_atomic(page);
2984                 *addr = cpu_to_le32(recon_state.nr_caps);
2985                 kunmap_atomic(addr);
2986         }
2987
2988         reply->hdr.data_len = cpu_to_le32(pagelist->length);
2989         ceph_msg_data_add_pagelist(reply, pagelist);
2990
2991         ceph_early_kick_flushing_caps(mdsc, session);
2992
2993         ceph_con_send(&session->s_con, reply);
2994
2995         mutex_unlock(&session->s_mutex);
2996
2997         mutex_lock(&mdsc->mutex);
2998         __wake_requests(mdsc, &session->s_waiting);
2999         mutex_unlock(&mdsc->mutex);
3000
3001         up_read(&mdsc->snap_rwsem);
3002         return;
3003
3004 fail:
3005         ceph_msg_put(reply);
3006         up_read(&mdsc->snap_rwsem);
3007         mutex_unlock(&session->s_mutex);
3008 fail_nomsg:
3009         ceph_pagelist_release(pagelist);
3010 fail_nopagelist:
3011         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3012         return;
3013 }
3014
3015
3016 /*
3017  * compare old and new mdsmaps, kicking requests
3018  * and closing out old connections as necessary
3019  *
3020  * called under mdsc->mutex.
3021  */
3022 static void check_new_map(struct ceph_mds_client *mdsc,
3023                           struct ceph_mdsmap *newmap,
3024                           struct ceph_mdsmap *oldmap)
3025 {
3026         int i;
3027         int oldstate, newstate;
3028         struct ceph_mds_session *s;
3029
3030         dout("check_new_map new %u old %u\n",
3031              newmap->m_epoch, oldmap->m_epoch);
3032
3033         for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
3034                 if (mdsc->sessions[i] == NULL)
3035                         continue;
3036                 s = mdsc->sessions[i];
3037                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3038                 newstate = ceph_mdsmap_get_state(newmap, i);
3039
3040                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3041                      i, ceph_mds_state_name(oldstate),
3042                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3043                      ceph_mds_state_name(newstate),
3044                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3045                      ceph_session_state_name(s->s_state));
3046
3047                 if (i >= newmap->m_max_mds ||
3048                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
3049                            ceph_mdsmap_get_addr(newmap, i),
3050                            sizeof(struct ceph_entity_addr))) {
3051                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
3052                                 /* the session never opened, just close it
3053                                  * out now */
3054                                 __wake_requests(mdsc, &s->s_waiting);
3055                                 __unregister_session(mdsc, s);
3056                         } else {
3057                                 /* just close it */
3058                                 mutex_unlock(&mdsc->mutex);
3059                                 mutex_lock(&s->s_mutex);
3060                                 mutex_lock(&mdsc->mutex);
3061                                 ceph_con_close(&s->s_con);
3062                                 mutex_unlock(&s->s_mutex);
3063                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
3064                         }
3065                 } else if (oldstate == newstate) {
3066                         continue;  /* nothing new with this mds */
3067                 }
3068
3069                 /*
3070                  * send reconnect?
3071                  */
3072                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3073                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3074                         mutex_unlock(&mdsc->mutex);
3075                         send_mds_reconnect(mdsc, s);
3076                         mutex_lock(&mdsc->mutex);
3077                 }
3078
3079                 /*
3080                  * kick request on any mds that has gone active.
3081                  */
3082                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3083                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3084                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3085                             oldstate != CEPH_MDS_STATE_STARTING)
3086                                 pr_info("mds%d recovery completed\n", s->s_mds);
3087                         kick_requests(mdsc, i);
3088                         ceph_kick_flushing_caps(mdsc, s);
3089                         wake_up_session_caps(s, 1);
3090                 }
3091         }
3092
3093         for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3094                 s = mdsc->sessions[i];
3095                 if (!s)
3096                         continue;
3097                 if (!ceph_mdsmap_is_laggy(newmap, i))
3098                         continue;
3099                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3100                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3101                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3102                         dout(" connecting to export targets of laggy mds%d\n",
3103                              i);
3104                         __open_export_target_sessions(mdsc, s);
3105                 }
3106         }
3107 }
3108
3109
3110
3111 /*
3112  * leases
3113  */
3114
3115 /*
3116  * caller must hold session s_mutex, dentry->d_lock
3117  */
3118 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3119 {
3120         struct ceph_dentry_info *di = ceph_dentry(dentry);
3121
3122         ceph_put_mds_session(di->lease_session);
3123         di->lease_session = NULL;
3124 }
3125
3126 static void handle_lease(struct ceph_mds_client *mdsc,
3127                          struct ceph_mds_session *session,
3128                          struct ceph_msg *msg)
3129 {
3130         struct super_block *sb = mdsc->fsc->sb;
3131         struct inode *inode;
3132         struct dentry *parent, *dentry;
3133         struct ceph_dentry_info *di;
3134         int mds = session->s_mds;
3135         struct ceph_mds_lease *h = msg->front.iov_base;
3136         u32 seq;
3137         struct ceph_vino vino;
3138         struct qstr dname;
3139         int release = 0;
3140
3141         dout("handle_lease from mds%d\n", mds);
3142
3143         /* decode */
3144         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3145                 goto bad;
3146         vino.ino = le64_to_cpu(h->ino);
3147         vino.snap = CEPH_NOSNAP;
3148         seq = le32_to_cpu(h->seq);
3149         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3150         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3151         if (dname.len != get_unaligned_le32(h+1))
3152                 goto bad;
3153
3154         /* lookup inode */
3155         inode = ceph_find_inode(sb, vino);
3156         dout("handle_lease %s, ino %llx %p %.*s\n",
3157              ceph_lease_op_name(h->action), vino.ino, inode,
3158              dname.len, dname.name);
3159
3160         mutex_lock(&session->s_mutex);
3161         session->s_seq++;
3162
3163         if (inode == NULL) {
3164                 dout("handle_lease no inode %llx\n", vino.ino);
3165                 goto release;
3166         }
3167
3168         /* dentry */
3169         parent = d_find_alias(inode);
3170         if (!parent) {
3171                 dout("no parent dentry on inode %p\n", inode);
3172                 WARN_ON(1);
3173                 goto release;  /* hrm... */
3174         }
3175         dname.hash = full_name_hash(dname.name, dname.len);
3176         dentry = d_lookup(parent, &dname);
3177         dput(parent);
3178         if (!dentry)
3179                 goto release;
3180
3181         spin_lock(&dentry->d_lock);
3182         di = ceph_dentry(dentry);
3183         switch (h->action) {
3184         case CEPH_MDS_LEASE_REVOKE:
3185                 if (di->lease_session == session) {
3186                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3187                                 h->seq = cpu_to_le32(di->lease_seq);
3188                         __ceph_mdsc_drop_dentry_lease(dentry);
3189                 }
3190                 release = 1;
3191                 break;
3192
3193         case CEPH_MDS_LEASE_RENEW:
3194                 if (di->lease_session == session &&
3195                     di->lease_gen == session->s_cap_gen &&
3196                     di->lease_renew_from &&
3197                     di->lease_renew_after == 0) {
3198                         unsigned long duration =
3199                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3200
3201                         di->lease_seq = seq;
3202                         dentry->d_time = di->lease_renew_from + duration;
3203                         di->lease_renew_after = di->lease_renew_from +
3204                                 (duration >> 1);
3205                         di->lease_renew_from = 0;
3206                 }
3207                 break;
3208         }
3209         spin_unlock(&dentry->d_lock);
3210         dput(dentry);
3211
3212         if (!release)
3213                 goto out;
3214
3215 release:
3216         /* let's just reuse the same message */
3217         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3218         ceph_msg_get(msg);
3219         ceph_con_send(&session->s_con, msg);
3220
3221 out:
3222         iput(inode);
3223         mutex_unlock(&session->s_mutex);
3224         return;
3225
3226 bad:
3227         pr_err("corrupt lease message\n");
3228         ceph_msg_dump(msg);
3229 }
3230
3231 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3232                               struct inode *inode,
3233                               struct dentry *dentry, char action,
3234                               u32 seq)
3235 {
3236         struct ceph_msg *msg;
3237         struct ceph_mds_lease *lease;
3238         int len = sizeof(*lease) + sizeof(u32);
3239         int dnamelen = 0;
3240
3241         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3242              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3243         dnamelen = dentry->d_name.len;
3244         len += dnamelen;
3245
3246         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3247         if (!msg)
3248                 return;
3249         lease = msg->front.iov_base;
3250         lease->action = action;
3251         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3252         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3253         lease->seq = cpu_to_le32(seq);
3254         put_unaligned_le32(dnamelen, lease + 1);
3255         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3256
3257         /*
3258          * if this is a preemptive lease RELEASE, no need to
3259          * flush request stream, since the actual request will
3260          * soon follow.
3261          */
3262         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3263
3264         ceph_con_send(&session->s_con, msg);
3265 }
3266
3267 /*
3268  * Preemptively release a lease we expect to invalidate anyway.
3269  * Pass @inode always, @dentry is optional.
3270  */
3271 void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
3272                              struct dentry *dentry)
3273 {
3274         struct ceph_dentry_info *di;
3275         struct ceph_mds_session *session;
3276         u32 seq;
3277
3278         BUG_ON(inode == NULL);
3279         BUG_ON(dentry == NULL);
3280
3281         /* is dentry lease valid? */
3282         spin_lock(&dentry->d_lock);
3283         di = ceph_dentry(dentry);
3284         if (!di || !di->lease_session ||
3285             di->lease_session->s_mds < 0 ||
3286             di->lease_gen != di->lease_session->s_cap_gen ||
3287             !time_before(jiffies, dentry->d_time)) {
3288                 dout("lease_release inode %p dentry %p -- "
3289                      "no lease\n",
3290                      inode, dentry);
3291                 spin_unlock(&dentry->d_lock);
3292                 return;
3293         }
3294
3295         /* we do have a lease on this dentry; note mds and seq */
3296         session = ceph_get_mds_session(di->lease_session);
3297         seq = di->lease_seq;
3298         __ceph_mdsc_drop_dentry_lease(dentry);
3299         spin_unlock(&dentry->d_lock);
3300
3301         dout("lease_release inode %p dentry %p to mds%d\n",
3302              inode, dentry, session->s_mds);
3303         ceph_mdsc_lease_send_msg(session, inode, dentry,
3304                                  CEPH_MDS_LEASE_RELEASE, seq);
3305         ceph_put_mds_session(session);
3306 }
3307
3308 /*
3309  * drop all leases (and dentry refs) in preparation for umount
3310  */
3311 static void drop_leases(struct ceph_mds_client *mdsc)
3312 {
3313         int i;
3314
3315         dout("drop_leases\n");
3316         mutex_lock(&mdsc->mutex);
3317         for (i = 0; i < mdsc->max_sessions; i++) {
3318                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3319                 if (!s)
3320                         continue;
3321                 mutex_unlock(&mdsc->mutex);
3322                 mutex_lock(&s->s_mutex);
3323                 mutex_unlock(&s->s_mutex);
3324                 ceph_put_mds_session(s);
3325                 mutex_lock(&mdsc->mutex);
3326         }
3327         mutex_unlock(&mdsc->mutex);
3328 }
3329
3330
3331
3332 /*
3333  * delayed work -- periodically trim expired leases, renew caps with mds
3334  */
3335 static void schedule_delayed(struct ceph_mds_client *mdsc)
3336 {
3337         int delay = 5;
3338         unsigned hz = round_jiffies_relative(HZ * delay);
3339         schedule_delayed_work(&mdsc->delayed_work, hz);
3340 }
3341
3342 static void delayed_work(struct work_struct *work)
3343 {
3344         int i;
3345         struct ceph_mds_client *mdsc =
3346                 container_of(work, struct ceph_mds_client, delayed_work.work);
3347         int renew_interval;
3348         int renew_caps;
3349
3350         dout("mdsc delayed_work\n");
3351         ceph_check_delayed_caps(mdsc);
3352
3353         mutex_lock(&mdsc->mutex);
3354         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3355         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3356                                    mdsc->last_renew_caps);
3357         if (renew_caps)
3358                 mdsc->last_renew_caps = jiffies;
3359
3360         for (i = 0; i < mdsc->max_sessions; i++) {
3361                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3362                 if (s == NULL)
3363                         continue;
3364                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3365                         dout("resending session close request for mds%d\n",
3366                              s->s_mds);
3367                         request_close_session(mdsc, s);
3368                         ceph_put_mds_session(s);
3369                         continue;
3370                 }
3371                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3372                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3373                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3374                                 pr_info("mds%d hung\n", s->s_mds);
3375                         }
3376                 }
3377                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3378                         /* this mds is failed or recovering, just wait */
3379                         ceph_put_mds_session(s);
3380                         continue;
3381                 }
3382                 mutex_unlock(&mdsc->mutex);
3383
3384                 mutex_lock(&s->s_mutex);
3385                 if (renew_caps)
3386                         send_renew_caps(mdsc, s);
3387                 else
3388                         ceph_con_keepalive(&s->s_con);
3389                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3390                     s->s_state == CEPH_MDS_SESSION_HUNG)
3391                         ceph_send_cap_releases(mdsc, s);
3392                 mutex_unlock(&s->s_mutex);
3393                 ceph_put_mds_session(s);
3394
3395                 mutex_lock(&mdsc->mutex);
3396         }
3397         mutex_unlock(&mdsc->mutex);
3398
3399         schedule_delayed(mdsc);
3400 }
3401
3402 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3403
3404 {
3405         struct ceph_mds_client *mdsc;
3406
3407         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3408         if (!mdsc)
3409                 return -ENOMEM;
3410         mdsc->fsc = fsc;
3411         fsc->mdsc = mdsc;
3412         mutex_init(&mdsc->mutex);
3413         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3414         if (mdsc->mdsmap == NULL) {
3415                 kfree(mdsc);
3416                 return -ENOMEM;
3417         }
3418
3419         init_completion(&mdsc->safe_umount_waiters);
3420         init_waitqueue_head(&mdsc->session_close_wq);
3421         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3422         mdsc->sessions = NULL;
3423         atomic_set(&mdsc->num_sessions, 0);
3424         mdsc->max_sessions = 0;
3425         mdsc->stopping = 0;
3426         mdsc->last_snap_seq = 0;
3427         init_rwsem(&mdsc->snap_rwsem);
3428         mdsc->snap_realms = RB_ROOT;
3429         INIT_LIST_HEAD(&mdsc->snap_empty);
3430         spin_lock_init(&mdsc->snap_empty_lock);
3431         mdsc->last_tid = 0;
3432         mdsc->oldest_tid = 0;
3433         mdsc->request_tree = RB_ROOT;
3434         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3435         mdsc->last_renew_caps = jiffies;
3436         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3437         spin_lock_init(&mdsc->cap_delay_lock);
3438         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3439         spin_lock_init(&mdsc->snap_flush_lock);
3440         mdsc->last_cap_flush_tid = 1;
3441         mdsc->cap_flush_tree = RB_ROOT;
3442         INIT_LIST_HEAD(&mdsc->cap_dirty);
3443         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3444         mdsc->num_cap_flushing = 0;
3445         spin_lock_init(&mdsc->cap_dirty_lock);
3446         init_waitqueue_head(&mdsc->cap_flushing_wq);
3447         spin_lock_init(&mdsc->dentry_lru_lock);
3448         INIT_LIST_HEAD(&mdsc->dentry_lru);
3449
3450         ceph_caps_init(mdsc);
3451         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3452
3453         init_rwsem(&mdsc->pool_perm_rwsem);
3454         mdsc->pool_perm_tree = RB_ROOT;
3455
3456         return 0;
3457 }
3458
3459 /*
3460  * Wait for safe replies on open mds requests.  If we time out, drop
3461  * all requests from the tree to avoid dangling dentry refs.
3462  */
3463 static void wait_requests(struct ceph_mds_client *mdsc)
3464 {
3465         struct ceph_options *opts = mdsc->fsc->client->options;
3466         struct ceph_mds_request *req;
3467
3468         mutex_lock(&mdsc->mutex);
3469         if (__get_oldest_req(mdsc)) {
3470                 mutex_unlock(&mdsc->mutex);
3471
3472                 dout("wait_requests waiting for requests\n");
3473                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3474                                     ceph_timeout_jiffies(opts->mount_timeout));
3475
3476                 /* tear down remaining requests */
3477                 mutex_lock(&mdsc->mutex);
3478                 while ((req = __get_oldest_req(mdsc))) {
3479                         dout("wait_requests timed out on tid %llu\n",
3480                              req->r_tid);
3481                         __unregister_request(mdsc, req);
3482                 }
3483         }
3484         mutex_unlock(&mdsc->mutex);
3485         dout("wait_requests done\n");
3486 }
3487
3488 /*
3489  * called before mount is ro, and before dentries are torn down.
3490  * (hmm, does this still race with new lookups?)
3491  */
3492 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3493 {
3494         dout("pre_umount\n");
3495         mdsc->stopping = 1;
3496
3497         drop_leases(mdsc);
3498         ceph_flush_dirty_caps(mdsc);
3499         wait_requests(mdsc);
3500
3501         /*
3502          * wait for reply handlers to drop their request refs and
3503          * their inode/dcache refs
3504          */
3505         ceph_msgr_flush();
3506 }
3507
3508 /*
3509  * wait for all write mds requests to flush.
3510  */
3511 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3512 {
3513         struct ceph_mds_request *req = NULL, *nextreq;
3514         struct rb_node *n;
3515
3516         mutex_lock(&mdsc->mutex);
3517         dout("wait_unsafe_requests want %lld\n", want_tid);
3518 restart:
3519         req = __get_oldest_req(mdsc);
3520         while (req && req->r_tid <= want_tid) {
3521                 /* find next request */
3522                 n = rb_next(&req->r_node);
3523                 if (n)
3524                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3525                 else
3526                         nextreq = NULL;
3527                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
3528                     (req->r_op & CEPH_MDS_OP_WRITE)) {
3529                         /* write op */
3530                         ceph_mdsc_get_request(req);
3531                         if (nextreq)
3532                                 ceph_mdsc_get_request(nextreq);
3533                         mutex_unlock(&mdsc->mutex);
3534                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3535                              req->r_tid, want_tid);
3536                         wait_for_completion(&req->r_safe_completion);
3537                         mutex_lock(&mdsc->mutex);
3538                         ceph_mdsc_put_request(req);
3539                         if (!nextreq)
3540                                 break;  /* next dne before, so we're done! */
3541                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3542                                 /* next request was removed from tree */
3543                                 ceph_mdsc_put_request(nextreq);
3544                                 goto restart;
3545                         }
3546                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3547                 }
3548                 req = nextreq;
3549         }
3550         mutex_unlock(&mdsc->mutex);
3551         dout("wait_unsafe_requests done\n");
3552 }
3553
3554 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3555 {
3556         u64 want_tid, want_flush, want_snap;
3557
3558         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3559                 return;
3560
3561         dout("sync\n");
3562         mutex_lock(&mdsc->mutex);
3563         want_tid = mdsc->last_tid;
3564         mutex_unlock(&mdsc->mutex);
3565
3566         ceph_flush_dirty_caps(mdsc);
3567         spin_lock(&mdsc->cap_dirty_lock);
3568         want_flush = mdsc->last_cap_flush_tid;
3569         spin_unlock(&mdsc->cap_dirty_lock);
3570
3571         down_read(&mdsc->snap_rwsem);
3572         want_snap = mdsc->last_snap_seq;
3573         up_read(&mdsc->snap_rwsem);
3574
3575         dout("sync want tid %lld flush_seq %lld snap_seq %lld\n",
3576              want_tid, want_flush, want_snap);
3577
3578         wait_unsafe_requests(mdsc, want_tid);
3579         wait_caps_flush(mdsc, want_flush, want_snap);
3580 }
3581
3582 /*
3583  * true if all sessions are closed, or we force unmount
3584  */
3585 static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3586 {
3587         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3588                 return true;
3589         return atomic_read(&mdsc->num_sessions) == 0;
3590 }
3591
3592 /*
3593  * called after sb is ro.
3594  */
3595 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3596 {
3597         struct ceph_options *opts = mdsc->fsc->client->options;
3598         struct ceph_mds_session *session;
3599         int i;
3600
3601         dout("close_sessions\n");
3602
3603         /* close sessions */
3604         mutex_lock(&mdsc->mutex);
3605         for (i = 0; i < mdsc->max_sessions; i++) {
3606                 session = __ceph_lookup_mds_session(mdsc, i);
3607                 if (!session)
3608                         continue;
3609                 mutex_unlock(&mdsc->mutex);
3610                 mutex_lock(&session->s_mutex);
3611                 __close_session(mdsc, session);
3612                 mutex_unlock(&session->s_mutex);
3613                 ceph_put_mds_session(session);
3614                 mutex_lock(&mdsc->mutex);
3615         }
3616         mutex_unlock(&mdsc->mutex);
3617
3618         dout("waiting for sessions to close\n");
3619         wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3620                            ceph_timeout_jiffies(opts->mount_timeout));
3621
3622         /* tear down remaining sessions */
3623         mutex_lock(&mdsc->mutex);
3624         for (i = 0; i < mdsc->max_sessions; i++) {
3625                 if (mdsc->sessions[i]) {
3626                         session = get_session(mdsc->sessions[i]);
3627                         __unregister_session(mdsc, session);
3628                         mutex_unlock(&mdsc->mutex);
3629                         mutex_lock(&session->s_mutex);
3630                         remove_session_caps(session);
3631                         mutex_unlock(&session->s_mutex);
3632                         ceph_put_mds_session(session);
3633                         mutex_lock(&mdsc->mutex);
3634                 }
3635         }
3636         WARN_ON(!list_empty(&mdsc->cap_delay_list));
3637         mutex_unlock(&mdsc->mutex);
3638
3639         ceph_cleanup_empty_realms(mdsc);
3640
3641         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3642
3643         dout("stopped\n");
3644 }
3645
3646 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3647 {
3648         dout("stop\n");
3649         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3650         if (mdsc->mdsmap)
3651                 ceph_mdsmap_destroy(mdsc->mdsmap);
3652         kfree(mdsc->sessions);
3653         ceph_caps_finalize(mdsc);
3654         ceph_pool_perm_destroy(mdsc);
3655 }
3656
3657 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3658 {
3659         struct ceph_mds_client *mdsc = fsc->mdsc;
3660
3661         dout("mdsc_destroy %p\n", mdsc);
3662         ceph_mdsc_stop(mdsc);
3663
3664         /* flush out any connection work with references to us */
3665         ceph_msgr_flush();
3666
3667         fsc->mdsc = NULL;
3668         kfree(mdsc);
3669         dout("mdsc_destroy %p done\n", mdsc);
3670 }
3671
3672
3673 /*
3674  * handle mds map update.
3675  */
3676 void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3677 {
3678         u32 epoch;
3679         u32 maplen;
3680         void *p = msg->front.iov_base;
3681         void *end = p + msg->front.iov_len;
3682         struct ceph_mdsmap *newmap, *oldmap;
3683         struct ceph_fsid fsid;
3684         int err = -EINVAL;
3685
3686         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3687         ceph_decode_copy(&p, &fsid, sizeof(fsid));
3688         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3689                 return;
3690         epoch = ceph_decode_32(&p);
3691         maplen = ceph_decode_32(&p);
3692         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3693
3694         /* do we need it? */
3695         ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
3696         mutex_lock(&mdsc->mutex);
3697         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3698                 dout("handle_map epoch %u <= our %u\n",
3699                      epoch, mdsc->mdsmap->m_epoch);
3700                 mutex_unlock(&mdsc->mutex);
3701                 return;
3702         }
3703
3704         newmap = ceph_mdsmap_decode(&p, end);
3705         if (IS_ERR(newmap)) {
3706                 err = PTR_ERR(newmap);
3707                 goto bad_unlock;
3708         }
3709
3710         /* swap into place */
3711         if (mdsc->mdsmap) {
3712                 oldmap = mdsc->mdsmap;
3713                 mdsc->mdsmap = newmap;
3714                 check_new_map(mdsc, newmap, oldmap);
3715                 ceph_mdsmap_destroy(oldmap);
3716         } else {
3717                 mdsc->mdsmap = newmap;  /* first mds map */
3718         }
3719         mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3720
3721         __wake_requests(mdsc, &mdsc->waiting_for_map);
3722
3723         mutex_unlock(&mdsc->mutex);
3724         schedule_delayed(mdsc);
3725         return;
3726
3727 bad_unlock:
3728         mutex_unlock(&mdsc->mutex);
3729 bad:
3730         pr_err("error decoding mdsmap %d\n", err);
3731         return;
3732 }
3733
3734 static struct ceph_connection *con_get(struct ceph_connection *con)
3735 {
3736         struct ceph_mds_session *s = con->private;
3737
3738         if (get_session(s)) {
3739                 dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3740                 return con;
3741         }
3742         dout("mdsc con_get %p FAIL\n", s);
3743         return NULL;
3744 }
3745
3746 static void con_put(struct ceph_connection *con)
3747 {
3748         struct ceph_mds_session *s = con->private;
3749
3750         dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3751         ceph_put_mds_session(s);
3752 }
3753
3754 /*
3755  * if the client is unresponsive for long enough, the mds will kill
3756  * the session entirely.
3757  */
3758 static void peer_reset(struct ceph_connection *con)
3759 {
3760         struct ceph_mds_session *s = con->private;
3761         struct ceph_mds_client *mdsc = s->s_mdsc;
3762
3763         pr_warn("mds%d closed our session\n", s->s_mds);
3764         send_mds_reconnect(mdsc, s);
3765 }
3766
3767 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3768 {
3769         struct ceph_mds_session *s = con->private;
3770         struct ceph_mds_client *mdsc = s->s_mdsc;
3771         int type = le16_to_cpu(msg->hdr.type);
3772
3773         mutex_lock(&mdsc->mutex);
3774         if (__verify_registered_session(mdsc, s) < 0) {
3775                 mutex_unlock(&mdsc->mutex);
3776                 goto out;
3777         }
3778         mutex_unlock(&mdsc->mutex);
3779
3780         switch (type) {
3781         case CEPH_MSG_MDS_MAP:
3782                 ceph_mdsc_handle_map(mdsc, msg);
3783                 break;
3784         case CEPH_MSG_CLIENT_SESSION:
3785                 handle_session(s, msg);
3786                 break;
3787         case CEPH_MSG_CLIENT_REPLY:
3788                 handle_reply(s, msg);
3789                 break;
3790         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3791                 handle_forward(mdsc, s, msg);
3792                 break;
3793         case CEPH_MSG_CLIENT_CAPS:
3794                 ceph_handle_caps(s, msg);
3795                 break;
3796         case CEPH_MSG_CLIENT_SNAP:
3797                 ceph_handle_snap(mdsc, s, msg);
3798                 break;
3799         case CEPH_MSG_CLIENT_LEASE:
3800                 handle_lease(mdsc, s, msg);
3801                 break;
3802
3803         default:
3804                 pr_err("received unknown message type %d %s\n", type,
3805                        ceph_msg_type_name(type));
3806         }
3807 out:
3808         ceph_msg_put(msg);
3809 }
3810
3811 /*
3812  * authentication
3813  */
3814
3815 /*
3816  * Note: returned pointer is the address of a structure that's
3817  * managed separately.  Caller must *not* attempt to free it.
3818  */
3819 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3820                                         int *proto, int force_new)
3821 {
3822         struct ceph_mds_session *s = con->private;
3823         struct ceph_mds_client *mdsc = s->s_mdsc;
3824         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3825         struct ceph_auth_handshake *auth = &s->s_auth;
3826
3827         if (force_new && auth->authorizer) {
3828                 ceph_auth_destroy_authorizer(ac, auth->authorizer);
3829                 auth->authorizer = NULL;
3830         }
3831         if (!auth->authorizer) {
3832                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3833                                                       auth);
3834                 if (ret)
3835                         return ERR_PTR(ret);
3836         } else {
3837                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3838                                                       auth);
3839                 if (ret)
3840                         return ERR_PTR(ret);
3841         }
3842         *proto = ac->protocol;
3843
3844         return auth;
3845 }
3846
3847
3848 static int verify_authorizer_reply(struct ceph_connection *con, int len)
3849 {
3850         struct ceph_mds_session *s = con->private;
3851         struct ceph_mds_client *mdsc = s->s_mdsc;
3852         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3853
3854         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3855 }
3856
3857 static int invalidate_authorizer(struct ceph_connection *con)
3858 {
3859         struct ceph_mds_session *s = con->private;
3860         struct ceph_mds_client *mdsc = s->s_mdsc;
3861         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3862
3863         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3864
3865         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3866 }
3867
3868 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3869                                 struct ceph_msg_header *hdr, int *skip)
3870 {
3871         struct ceph_msg *msg;
3872         int type = (int) le16_to_cpu(hdr->type);
3873         int front_len = (int) le32_to_cpu(hdr->front_len);
3874
3875         if (con->in_msg)
3876                 return con->in_msg;
3877
3878         *skip = 0;
3879         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3880         if (!msg) {
3881                 pr_err("unable to allocate msg type %d len %d\n",
3882                        type, front_len);
3883                 return NULL;
3884         }
3885
3886         return msg;
3887 }
3888
3889 static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
3890 {
3891        struct ceph_mds_session *s = con->private;
3892        struct ceph_auth_handshake *auth = &s->s_auth;
3893        return ceph_auth_sign_message(auth, msg);
3894 }
3895
3896 static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
3897 {
3898        struct ceph_mds_session *s = con->private;
3899        struct ceph_auth_handshake *auth = &s->s_auth;
3900        return ceph_auth_check_message_signature(auth, msg);
3901 }
3902
3903 static const struct ceph_connection_operations mds_con_ops = {
3904         .get = con_get,
3905         .put = con_put,
3906         .dispatch = dispatch,
3907         .get_authorizer = get_authorizer,
3908         .verify_authorizer_reply = verify_authorizer_reply,
3909         .invalidate_authorizer = invalidate_authorizer,
3910         .peer_reset = peer_reset,
3911         .alloc_msg = mds_alloc_msg,
3912         .sign_message = sign_message,
3913         .check_message_signature = check_message_signature,
3914 };
3915
3916 /* eof */