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  45  * are no longer valid.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