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
  12 #include "super.h"
  13 #include "mds_client.h"
  14
  15 #include <linux/ceph/ceph_features.h>
  16 #include <linux/ceph/messenger.h>
  17 #include <linux/ceph/decode.h>
  18 #include <linux/ceph/pagelist.h>
  19 #include <linux/ceph/auth.h>
  20 #include <linux/ceph/debugfs.h>
  21
  22 /*
  23  * A cluster of MDS (metadata server) daemons is responsible for
  24  * managing the file system namespace (the directory hierarchy and
  25  * inodes) and for coordinating shared access to storage.  Metadata is
  26  * partitioning hierarchically across a number of servers, and that
  27  * partition varies over time as the cluster adjusts the distribution
  28  * in order to balance load.
  29  *
  30  * The MDS client is primarily responsible to managing synchronous
  31  * metadata requests for operations like open, unlink, and so forth.
  32  * If there is a MDS failure, we find out about it when we (possibly
  33  * request and) receive a new MDS map, and can resubmit affected
  34  * requests.
  35  *
  36  * For the most part, though, we take advantage of a lossless
  37  * communications channel to the MDS, and do not need to worry about
  38  * timing out or resubmitting requests.
  39  *
  40  * We maintain a stateful "session" with each MDS we interact with.
  41  * Within each session, we sent periodic heartbeat messages to ensure
  42  * any capabilities or leases we have been issues remain valid.  If
  43  * the session times out and goes stale, our leases and capabilities
  44  * are no longer valid.
  45  */
  46
  47 struct ceph_reconnect_state {
  48         int nr_caps;
  49         struct ceph_pagelist *pagelist;
  50         bool flock;
  51 };
  52
  53 static void __wake_requests(struct ceph_mds_client *mdsc,
  54                             struct list_head *head);
  55
  56 static const struct ceph_connection_operations mds_con_ops;
  57
  58
  59 /*
  60  * mds reply parsing
  61  */
  62
  63 /*
  64  * parse individual inode info
  65  */
  66 static int parse_reply_info_in(void **p, void *end,
  67                                struct ceph_mds_reply_info_in *info,
  68                                u64 features)
  69 {
  70         int err = -EIO;
  71
  72         info->in = *p;
  73         *p += sizeof(struct ceph_mds_reply_inode) +
  74                 sizeof(*info->in->fragtree.splits) *
  75                 le32_to_cpu(info->in->fragtree.nsplits);
  76
  77         ceph_decode_32_safe(p, end, info->symlink_len, bad);
  78         ceph_decode_need(p, end, info->symlink_len, bad);
  79         info->symlink = *p;
  80         *p += info->symlink_len;
  81
  82         if (features & CEPH_FEATURE_DIRLAYOUTHASH)
  83                 ceph_decode_copy_safe(p, end, &info->dir_layout,
  84                                       sizeof(info->dir_layout), bad);
  85         else
  86                 memset(&info->dir_layout, 0, sizeof(info->dir_layout));
  87
  88         ceph_decode_32_safe(p, end, info->xattr_len, bad);
  89         ceph_decode_need(p, end, info->xattr_len, bad);
  90         info->xattr_data = *p;
  91         *p += info->xattr_len;
  92
  93         if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
  94                 ceph_decode_64_safe(p, end, info->inline_version, bad);
  95                 ceph_decode_32_safe(p, end, info->inline_len, bad);
  96                 ceph_decode_need(p, end, info->inline_len, bad);
  97                 info->inline_data = *p;
  98                 *p += info->inline_len;
  99         } else
 100                 info->inline_version = CEPH_INLINE_NONE;
 101
 102         return 0;
 103 bad:
 104         return err;
 105 }
 106
 107 /*
 108  * parse a normal reply, which may contain a (dir+)dentry and/or a
 109  * target inode.
 110  */
 111 static int parse_reply_info_trace(void **p, void *end,
 112                                   struct ceph_mds_reply_info_parsed *info,
 113                                   u64 features)
 114 {
 115         int err;
 116
 117         if (info->head->is_dentry) {
 118                 err = parse_reply_info_in(p, end, &info->diri, features);
 119                 if (err < 0)
 120                         goto out_bad;
 121
 122                 if (unlikely(*p + sizeof(*info->dirfrag) > end))
 123                         goto bad;
 124                 info->dirfrag = *p;
 125                 *p += sizeof(*info->dirfrag) +
 126                         sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 127                 if (unlikely(*p > end))
 128                         goto bad;
 129
 130                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 131                 ceph_decode_need(p, end, info->dname_len, bad);
 132                 info->dname = *p;
 133                 *p += info->dname_len;
 134                 info->dlease = *p;
 135                 *p += sizeof(*info->dlease);
 136         }
 137
 138         if (info->head->is_target) {
 139                 err = parse_reply_info_in(p, end, &info->targeti, features);
 140                 if (err < 0)
 141                         goto out_bad;
 142         }
 143
 144         if (unlikely(*p != end))
 145                 goto bad;
 146         return 0;
 147
 148 bad:
 149         err = -EIO;
 150 out_bad:
 151         pr_err("problem parsing mds trace %d\n", err);
 152         return err;
 153 }
 154
 155 /*
 156  * parse readdir results
 157  */
 158 static int parse_reply_info_dir(void **p, void *end,
 159                                 struct ceph_mds_reply_info_parsed *info,
 160                                 u64 features)
 161 {
 162         u32 num, i = 0;
 163         int err;
 164
 165         info->dir_dir = *p;
 166         if (*p + sizeof(*info->dir_dir) > end)
 167                 goto bad;
 168         *p += sizeof(*info->dir_dir) +
 169                 sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 170         if (*p > end)
 171                 goto bad;
 172
 173         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 174         num = ceph_decode_32(p);
 175         info->dir_end = ceph_decode_8(p);
 176         info->dir_complete = ceph_decode_8(p);
 177         if (num == 0)
 178                 goto done;
 179
 180         BUG_ON(!info->dir_in);
 181         info->dir_dname = (void *)(info->dir_in + num);
 182         info->dir_dname_len = (void *)(info->dir_dname + num);
 183         info->dir_dlease = (void *)(info->dir_dname_len + num);
 184         if ((unsigned long)(info->dir_dlease + num) >
 185             (unsigned long)info->dir_in + info->dir_buf_size) {
 186                 pr_err("dir contents are larger than expected\n");
 187                 WARN_ON(1);
 188                 goto bad;
 189         }
 190
 191         info->dir_nr = num;
 192         while (num) {
 193                 /* dentry */
 194                 ceph_decode_need(p, end, sizeof(u32)*2, bad);
 195                 info->dir_dname_len[i] = ceph_decode_32(p);
 196                 ceph_decode_need(p, end, info->dir_dname_len[i], bad);
 197                 info->dir_dname[i] = *p;
 198                 *p += info->dir_dname_len[i];
 199                 dout("parsed dir dname '%.*s'\n", info->dir_dname_len[i],
 200                      info->dir_dname[i]);
 201                 info->dir_dlease[i] = *p;
 202                 *p += sizeof(struct ceph_mds_reply_lease);
 203
 204                 /* inode */
 205                 err = parse_reply_info_in(p, end, &info->dir_in[i], features);
 206                 if (err < 0)
 207                         goto out_bad;
 208                 i++;
 209                 num--;
 210         }
 211
 212 done:
 213         if (*p != end)
 214                 goto bad;
 215         return 0;
 216
 217 bad:
 218         err = -EIO;
 219 out_bad:
 220         pr_err("problem parsing dir contents %d\n", err);
 221         return err;
 222 }
 223
 224 /*
 225  * parse fcntl F_GETLK results
 226  */
 227 static int parse_reply_info_filelock(void **p, void *end,
 228                                      struct ceph_mds_reply_info_parsed *info,
 229                                      u64 features)
 230 {
 231         if (*p + sizeof(*info->filelock_reply) > end)
 232                 goto bad;
 233
 234         info->filelock_reply = *p;
 235         *p += sizeof(*info->filelock_reply);
 236
 237         if (unlikely(*p != end))
 238                 goto bad;
 239         return 0;
 240
 241 bad:
 242         return -EIO;
 243 }
 244
 245 /*
 246  * parse create results
 247  */
 248 static int parse_reply_info_create(void **p, void *end,
 249                                   struct ceph_mds_reply_info_parsed *info,
 250                                   u64 features)
 251 {
 252         if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 253                 if (*p == end) {
 254                         info->has_create_ino = false;
 255                 } else {
 256                         info->has_create_ino = true;
 257                         info->ino = ceph_decode_64(p);
 258                 }
 259         }
 260
 261         if (unlikely(*p != end))
 262                 goto bad;
 263         return 0;
 264
 265 bad:
 266         return -EIO;
 267 }
 268
 269 /*
 270  * parse extra results
 271  */
 272 static int parse_reply_info_extra(void **p, void *end,
 273                                   struct ceph_mds_reply_info_parsed *info,
 274                                   u64 features)
 275 {
 276         if (info->head->op == CEPH_MDS_OP_GETFILELOCK)
 277                 return parse_reply_info_filelock(p, end, info, features);
 278         else if (info->head->op == CEPH_MDS_OP_READDIR ||
 279                  info->head->op == CEPH_MDS_OP_LSSNAP)
 280                 return parse_reply_info_dir(p, end, info, features);
 281         else if (info->head->op == CEPH_MDS_OP_CREATE)
 282                 return parse_reply_info_create(p, end, info, features);
 283         else
 284                 return -EIO;
 285 }
 286
 287 /*
 288  * parse entire mds reply
 289  */
 290 static int parse_reply_info(struct ceph_msg *msg,
 291                             struct ceph_mds_reply_info_parsed *info,
 292                             u64 features)
 293 {
 294         void *p, *end;
 295         u32 len;
 296         int err;
 297
 298         info->head = msg->front.iov_base;
 299         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 300         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 301
 302         /* trace */
 303         ceph_decode_32_safe(&p, end, len, bad);
 304         if (len > 0) {
 305                 ceph_decode_need(&p, end, len, bad);
 306                 err = parse_reply_info_trace(&p, p+len, info, features);
 307                 if (err < 0)
 308                         goto out_bad;
 309         }
 310
 311         /* extra */
 312         ceph_decode_32_safe(&p, end, len, bad);
 313         if (len > 0) {
 314                 ceph_decode_need(&p, end, len, bad);
 315                 err = parse_reply_info_extra(&p, p+len, info, features);
 316                 if (err < 0)
 317                         goto out_bad;
 318         }
 319
 320         /* snap blob */
 321         ceph_decode_32_safe(&p, end, len, bad);
 322         info->snapblob_len = len;
 323         info->snapblob = p;
 324         p += len;
 325
 326         if (p != end)
 327                 goto bad;
 328         return 0;
 329
 330 bad:
 331         err = -EIO;
 332 out_bad:
 333         pr_err("mds parse_reply err %d\n", err);
 334         return err;
 335 }
 336
 337 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 338 {
 339         if (!info->dir_in)
 340                 return;
 341         free_pages((unsigned long)info->dir_in, get_order(info->dir_buf_size));
 342 }
 343
 344
 345 /*
 346  * sessions
 347  */
 348 const char *ceph_session_state_name(int s)
 349 {
 350         switch (s) {
 351         case CEPH_MDS_SESSION_NEW: return "new";
 352         case CEPH_MDS_SESSION_OPENING: return "opening";
 353         case CEPH_MDS_SESSION_OPEN: return "open";
 354         case CEPH_MDS_SESSION_HUNG: return "hung";
 355         case CEPH_MDS_SESSION_CLOSING: return "closing";
 356         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 357         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 358         default: return "???";
 359         }
 360 }
 361
 362 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 363 {
 364         if (atomic_inc_not_zero(&s->s_ref)) {
 365                 dout("mdsc get_session %p %d -> %d\n", s,
 366                      atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
 367                 return s;
 368         } else {
 369                 dout("mdsc get_session %p 0 -- FAIL", s);
 370                 return NULL;
 371         }
 372 }
 373
 374 void ceph_put_mds_session(struct ceph_mds_session *s)
 375 {
 376         dout("mdsc put_session %p %d -> %d\n", s,
 377              atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
 378         if (atomic_dec_and_test(&s->s_ref)) {
 379                 if (s->s_auth.authorizer)
 380                         ceph_auth_destroy_authorizer(
 381                                 s->s_mdsc->fsc->client->monc.auth,
 382                                 s->s_auth.authorizer);
 383                 kfree(s);
 384         }
 385 }
 386
 387 /*
 388  * called under mdsc->mutex
 389  */
 390 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 391                                                    int mds)
 392 {
 393         struct ceph_mds_session *session;
 394
 395         if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
 396                 return NULL;
 397         session = mdsc->sessions[mds];
 398         dout("lookup_mds_session %p %d\n", session,
 399              atomic_read(&session->s_ref));
 400         get_session(session);
 401         return session;
 402 }
 403
 404 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 405 {
 406         if (mds >= mdsc->max_sessions)
 407                 return false;
 408         return mdsc->sessions[mds];
 409 }
 410
 411 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 412                                        struct ceph_mds_session *s)
 413 {
 414         if (s->s_mds >= mdsc->max_sessions ||
 415             mdsc->sessions[s->s_mds] != s)
 416                 return -ENOENT;
 417         return 0;
 418 }
 419
 420 /*
 421  * create+register a new session for given mds.
 422  * called under mdsc->mutex.
 423  */
 424 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 425                                                  int mds)
 426 {
 427         struct ceph_mds_session *s;
 428
 429         if (mds >= mdsc->mdsmap->m_max_mds)
 430                 return ERR_PTR(-EINVAL);
 431
 432         s = kzalloc(sizeof(*s), GFP_NOFS);
 433         if (!s)
 434                 return ERR_PTR(-ENOMEM);
 435         s->s_mdsc = mdsc;
 436         s->s_mds = mds;
 437         s->s_state = CEPH_MDS_SESSION_NEW;
 438         s->s_ttl = 0;
 439         s->s_seq = 0;
 440         mutex_init(&s->s_mutex);
 441
 442         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 443
 444         spin_lock_init(&s->s_gen_ttl_lock);
 445         s->s_cap_gen = 0;
 446         s->s_cap_ttl = jiffies - 1;
 447
 448         spin_lock_init(&s->s_cap_lock);
 449         s->s_renew_requested = 0;
 450         s->s_renew_seq = 0;
 451         INIT_LIST_HEAD(&s->s_caps);
 452         s->s_nr_caps = 0;
 453         s->s_trim_caps = 0;
 454         atomic_set(&s->s_ref, 1);
 455         INIT_LIST_HEAD(&s->s_waiting);
 456         INIT_LIST_HEAD(&s->s_unsafe);
 457         s->s_num_cap_releases = 0;
 458         s->s_cap_reconnect = 0;
 459         s->s_cap_iterator = NULL;
 460         INIT_LIST_HEAD(&s->s_cap_releases);
 461         INIT_LIST_HEAD(&s->s_cap_releases_done);
 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 (dir) {
 633                 struct ceph_inode_info *ci = ceph_inode(dir);
 634
 635                 ihold(dir);
 636                 spin_lock(&ci->i_unsafe_lock);
 637                 req->r_unsafe_dir = dir;
 638                 list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 639                 spin_unlock(&ci->i_unsafe_lock);
 640         }
 641 }
 642
 643 static void __unregister_request(struct ceph_mds_client *mdsc,
 644                                  struct ceph_mds_request *req)
 645 {
 646         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 647         rb_erase(&req->r_node, &mdsc->request_tree);
 648         RB_CLEAR_NODE(&req->r_node);
 649
 650         if (req->r_unsafe_dir) {
 651                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 652
 653                 spin_lock(&ci->i_unsafe_lock);
 654                 list_del_init(&req->r_unsafe_dir_item);
 655                 spin_unlock(&ci->i_unsafe_lock);
 656
 657                 iput(req->r_unsafe_dir);
 658                 req->r_unsafe_dir = NULL;
 659         }
 660
 661         complete_all(&req->r_safe_completion);
 662
 663         ceph_mdsc_put_request(req);
 664 }
 665
 666 /*
 667  * Choose mds to send request to next.  If there is a hint set in the
 668  * request (e.g., due to a prior forward hint from the mds), use that.
 669  * Otherwise, consult frag tree and/or caps to identify the
 670  * appropriate mds.  If all else fails, choose randomly.
 671  *
 672  * Called under mdsc->mutex.
 673  */
 674 static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 675 {
 676         /*
 677          * we don't need to worry about protecting the d_parent access
 678          * here because we never renaming inside the snapped namespace
 679          * except to resplice to another snapdir, and either the old or new
 680          * result is a valid result.
 681          */
 682         while (!IS_ROOT(dentry) && ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
 683                 dentry = dentry->d_parent;
 684         return dentry;
 685 }
 686
 687 static int __choose_mds(struct ceph_mds_client *mdsc,
 688                         struct ceph_mds_request *req)
 689 {
 690         struct inode *inode;
 691         struct ceph_inode_info *ci;
 692         struct ceph_cap *cap;
 693         int mode = req->r_direct_mode;
 694         int mds = -1;
 695         u32 hash = req->r_direct_hash;
 696         bool is_hash = req->r_direct_is_hash;
 697
 698         /*
 699          * is there a specific mds we should try?  ignore hint if we have
 700          * no session and the mds is not up (active or recovering).
 701          */
 702         if (req->r_resend_mds >= 0 &&
 703             (__have_session(mdsc, req->r_resend_mds) ||
 704              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 705                 dout("choose_mds using resend_mds mds%d\n",
 706                      req->r_resend_mds);
 707                 return req->r_resend_mds;
 708         }
 709
 710         if (mode == USE_RANDOM_MDS)
 711                 goto random;
 712
 713         inode = NULL;
 714         if (req->r_inode) {
 715                 inode = req->r_inode;
 716         } else if (req->r_dentry) {
 717                 /* ignore race with rename; old or new d_parent is okay */
 718                 struct dentry *parent = req->r_dentry->d_parent;
 719                 struct inode *dir = d_inode(parent);
 720
 721                 if (dir->i_sb != mdsc->fsc->sb) {
 722                         /* not this fs! */
 723                         inode = d_inode(req->r_dentry);
 724                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 725                         /* direct snapped/virtual snapdir requests
 726                          * based on parent dir inode */
 727                         struct dentry *dn = get_nonsnap_parent(parent);
 728                         inode = d_inode(dn);
 729                         dout("__choose_mds using nonsnap parent %p\n", inode);
 730                 } else {
 731                         /* dentry target */
 732                         inode = d_inode(req->r_dentry);
 733                         if (!inode || mode == USE_AUTH_MDS) {
 734                                 /* dir + name */
 735                                 inode = dir;
 736                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 737                                 is_hash = true;
 738                         }
 739                 }
 740         }
 741
 742         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 743              (int)hash, mode);
 744         if (!inode)
 745                 goto random;
 746         ci = ceph_inode(inode);
 747
 748         if (is_hash && S_ISDIR(inode->i_mode)) {
 749                 struct ceph_inode_frag frag;
 750                 int found;
 751
 752                 ceph_choose_frag(ci, hash, &frag, &found);
 753                 if (found) {
 754                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 755                                 u8 r;
 756
 757                                 /* choose a random replica */
 758                                 get_random_bytes(&r, 1);
 759                                 r %= frag.ndist;
 760                                 mds = frag.dist[r];
 761                                 dout("choose_mds %p %llx.%llx "
 762                                      "frag %u mds%d (%d/%d)\n",
 763                                      inode, ceph_vinop(inode),
 764                                      frag.frag, mds,
 765                                      (int)r, frag.ndist);
 766                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 767                                     CEPH_MDS_STATE_ACTIVE)
 768                                         return mds;
 769                         }
 770
 771                         /* since this file/dir wasn't known to be
 772                          * replicated, then we want to look for the
 773                          * authoritative mds. */
 774                         mode = USE_AUTH_MDS;
 775                         if (frag.mds >= 0) {
 776                                 /* choose auth mds */
 777                                 mds = frag.mds;
 778                                 dout("choose_mds %p %llx.%llx "
 779                                      "frag %u mds%d (auth)\n",
 780                                      inode, ceph_vinop(inode), frag.frag, mds);
 781                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 782                                     CEPH_MDS_STATE_ACTIVE)
 783                                         return mds;
 784                         }
 785                 }
 786         }
 787
 788         spin_lock(&ci->i_ceph_lock);
 789         cap = NULL;
 790         if (mode == USE_AUTH_MDS)
 791                 cap = ci->i_auth_cap;
 792         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 793                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 794         if (!cap) {
 795                 spin_unlock(&ci->i_ceph_lock);
 796                 goto random;
 797         }
 798         mds = cap->session->s_mds;
 799         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 800              inode, ceph_vinop(inode), mds,
 801              cap == ci->i_auth_cap ? "auth " : "", cap);
 802         spin_unlock(&ci->i_ceph_lock);
 803         return mds;
 804
 805 random:
 806         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 807         dout("choose_mds chose random mds%d\n", mds);
 808         return mds;
 809 }
 810
 811
 812 /*
 813  * session messages
 814  */
 815 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 816 {
 817         struct ceph_msg *msg;
 818         struct ceph_mds_session_head *h;
 819
 820         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 821                            false);
 822         if (!msg) {
 823                 pr_err("create_session_msg ENOMEM creating msg\n");
 824                 return NULL;
 825         }
 826         h = msg->front.iov_base;
 827         h->op = cpu_to_le32(op);
 828         h->seq = cpu_to_le64(seq);
 829
 830         return msg;
 831 }
 832
 833 /*
 834  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
 835  * to include additional client metadata fields.
 836  */
 837 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
 838 {
 839         struct ceph_msg *msg;
 840         struct ceph_mds_session_head *h;
 841         int i = -1;
 842         int metadata_bytes = 0;
 843         int metadata_key_count = 0;
 844         struct ceph_options *opt = mdsc->fsc->client->options;
 845         void *p;
 846
 847         const char* metadata[][2] = {
 848                 {"hostname", utsname()->nodename},
 849                 {"kernel_version", utsname()->release},
 850                 {"entity_id", opt->name ? opt->name : ""},
 851                 {NULL, NULL}
 852         };
 853
 854         /* Calculate serialized length of metadata */
 855         metadata_bytes = 4;  /* map length */
 856         for (i = 0; metadata[i][0] != NULL; ++i) {
 857                 metadata_bytes += 8 + strlen(metadata[i][0]) +
 858                         strlen(metadata[i][1]);
 859                 metadata_key_count++;
 860         }
 861
 862         /* Allocate the message */
 863         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + metadata_bytes,
 864                            GFP_NOFS, false);
 865         if (!msg) {
 866                 pr_err("create_session_msg ENOMEM creating msg\n");
 867                 return NULL;
 868         }
 869         h = msg->front.iov_base;
 870         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 871         h->seq = cpu_to_le64(seq);
 872
 873         /*
 874          * Serialize client metadata into waiting buffer space, using
 875          * the format that userspace expects for map<string, string>
 876          *
 877          * ClientSession messages with metadata are v2
 878          */
 879         msg->hdr.version = cpu_to_le16(2);
 880         msg->hdr.compat_version = cpu_to_le16(1);
 881
 882         /* The write pointer, following the session_head structure */
 883         p = msg->front.iov_base + sizeof(*h);
 884
 885         /* Number of entries in the map */
 886         ceph_encode_32(&p, metadata_key_count);
 887
 888         /* Two length-prefixed strings for each entry in the map */
 889         for (i = 0; metadata[i][0] != NULL; ++i) {
 890                 size_t const key_len = strlen(metadata[i][0]);
 891                 size_t const val_len = strlen(metadata[i][1]);
 892
 893                 ceph_encode_32(&p, key_len);
 894                 memcpy(p, metadata[i][0], key_len);
 895                 p += key_len;
 896                 ceph_encode_32(&p, val_len);
 897                 memcpy(p, metadata[i][1], val_len);
 898                 p += val_len;
 899         }
 900
 901         return msg;
 902 }
 903
 904 /*
 905  * send session open request.
 906  *
 907  * called under mdsc->mutex
 908  */
 909 static int __open_session(struct ceph_mds_client *mdsc,
 910                           struct ceph_mds_session *session)
 911 {
 912         struct ceph_msg *msg;
 913         int mstate;
 914         int mds = session->s_mds;
 915
 916         /* wait for mds to go active? */
 917         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 918         dout("open_session to mds%d (%s)\n", mds,
 919              ceph_mds_state_name(mstate));
 920         session->s_state = CEPH_MDS_SESSION_OPENING;
 921         session->s_renew_requested = jiffies;
 922
 923         /* send connect message */
 924         msg = create_session_open_msg(mdsc, session->s_seq);
 925         if (!msg)
 926                 return -ENOMEM;
 927         ceph_con_send(&session->s_con, msg);
 928         return 0;
 929 }
 930
 931 /*
 932  * open sessions for any export targets for the given mds
 933  *
 934  * called under mdsc->mutex
 935  */
 936 static struct ceph_mds_session *
 937 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
 938 {
 939         struct ceph_mds_session *session;
 940
 941         session = __ceph_lookup_mds_session(mdsc, target);
 942         if (!session) {
 943                 session = register_session(mdsc, target);
 944                 if (IS_ERR(session))
 945                         return session;
 946         }
 947         if (session->s_state == CEPH_MDS_SESSION_NEW ||
 948             session->s_state == CEPH_MDS_SESSION_CLOSING)
 949                 __open_session(mdsc, session);
 950
 951         return session;
 952 }
 953
 954 struct ceph_mds_session *
 955 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
 956 {
 957         struct ceph_mds_session *session;
 958
 959         dout("open_export_target_session to mds%d\n", target);
 960
 961         mutex_lock(&mdsc->mutex);
 962         session = __open_export_target_session(mdsc, target);
 963         mutex_unlock(&mdsc->mutex);
 964
 965         return session;
 966 }
 967
 968 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 969                                           struct ceph_mds_session *session)
 970 {
 971         struct ceph_mds_info *mi;
 972         struct ceph_mds_session *ts;
 973         int i, mds = session->s_mds;
 974
 975         if (mds >= mdsc->mdsmap->m_max_mds)
 976                 return;
 977
 978         mi = &mdsc->mdsmap->m_info[mds];
 979         dout("open_export_target_sessions for mds%d (%d targets)\n",
 980              session->s_mds, mi->num_export_targets);
 981
 982         for (i = 0; i < mi->num_export_targets; i++) {
 983                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
 984                 if (!IS_ERR(ts))
 985                         ceph_put_mds_session(ts);
 986         }
 987 }
 988
 989 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 990                                            struct ceph_mds_session *session)
 991 {
 992         mutex_lock(&mdsc->mutex);
 993         __open_export_target_sessions(mdsc, session);
 994         mutex_unlock(&mdsc->mutex);
 995 }
 996
 997 /*
 998  * session caps
 999  */
1000
1001 /*
1002  * Free preallocated cap messages assigned to this session
1003  */
1004 static void cleanup_cap_releases(struct ceph_mds_session *session)
1005 {
1006         struct ceph_msg *msg;
1007
1008         spin_lock(&session->s_cap_lock);
1009         while (!list_empty(&session->s_cap_releases)) {
1010                 msg = list_first_entry(&session->s_cap_releases,
1011                                        struct ceph_msg, list_head);
1012                 list_del_init(&msg->list_head);
1013                 ceph_msg_put(msg);
1014         }
1015         while (!list_empty(&session->s_cap_releases_done)) {
1016                 msg = list_first_entry(&session->s_cap_releases_done,
1017                                        struct ceph_msg, list_head);
1018                 list_del_init(&msg->list_head);
1019                 ceph_msg_put(msg);
1020         }
1021         spin_unlock(&session->s_cap_lock);
1022 }
1023
1024 /*
1025  * Helper to safely iterate over all caps associated with a session, with
1026  * special care taken to handle a racing __ceph_remove_cap().
1027  *
1028  * Caller must hold session s_mutex.
1029  */
1030 static int iterate_session_caps(struct ceph_mds_session *session,
1031                                  int (*cb)(struct inode *, struct ceph_cap *,
1032                                             void *), void *arg)
1033 {
1034         struct list_head *p;
1035         struct ceph_cap *cap;
1036         struct inode *inode, *last_inode = NULL;
1037         struct ceph_cap *old_cap = NULL;
1038         int ret;
1039
1040         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1041         spin_lock(&session->s_cap_lock);
1042         p = session->s_caps.next;
1043         while (p != &session->s_caps) {
1044                 cap = list_entry(p, struct ceph_cap, session_caps);
1045                 inode = igrab(&cap->ci->vfs_inode);
1046                 if (!inode) {
1047                         p = p->next;
1048                         continue;
1049                 }
1050                 session->s_cap_iterator = cap;
1051                 spin_unlock(&session->s_cap_lock);
1052
1053                 if (last_inode) {
1054                         iput(last_inode);
1055                         last_inode = NULL;
1056                 }
1057                 if (old_cap) {
1058                         ceph_put_cap(session->s_mdsc, old_cap);
1059                         old_cap = NULL;
1060                 }
1061
1062                 ret = cb(inode, cap, arg);
1063                 last_inode = inode;
1064
1065                 spin_lock(&session->s_cap_lock);
1066                 p = p->next;
1067                 if (cap->ci == NULL) {
1068                         dout("iterate_session_caps  finishing cap %p removal\n",
1069                              cap);
1070                         BUG_ON(cap->session != session);
1071                         list_del_init(&cap->session_caps);
1072                         session->s_nr_caps--;
1073                         cap->session = NULL;
1074                         old_cap = cap;  /* put_cap it w/o locks held */
1075                 }
1076                 if (ret < 0)
1077                         goto out;
1078         }
1079         ret = 0;
1080 out:
1081         session->s_cap_iterator = NULL;
1082         spin_unlock(&session->s_cap_lock);
1083
1084         iput(last_inode);
1085         if (old_cap)
1086                 ceph_put_cap(session->s_mdsc, old_cap);
1087
1088         return ret;
1089 }
1090
1091 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1092                                   void *arg)
1093 {
1094         struct ceph_inode_info *ci = ceph_inode(inode);
1095         int drop = 0;
1096
1097         dout("removing cap %p, ci is %p, inode is %p\n",
1098              cap, ci, &ci->vfs_inode);
1099         spin_lock(&ci->i_ceph_lock);
1100         __ceph_remove_cap(cap, false);
1101         if (!__ceph_is_any_real_caps(ci)) {
1102                 struct ceph_mds_client *mdsc =
1103                         ceph_sb_to_client(inode->i_sb)->mdsc;
1104
1105                 spin_lock(&mdsc->cap_dirty_lock);
1106                 if (!list_empty(&ci->i_dirty_item)) {
1107                         pr_info(" dropping dirty %s state for %p %lld\n",
1108                                 ceph_cap_string(ci->i_dirty_caps),
1109                                 inode, ceph_ino(inode));
1110                         ci->i_dirty_caps = 0;
1111                         list_del_init(&ci->i_dirty_item);
1112                         drop = 1;
1113                 }
1114                 if (!list_empty(&ci->i_flushing_item)) {
1115                         pr_info(" dropping dirty+flushing %s state for %p %lld\n",
1116                                 ceph_cap_string(ci->i_flushing_caps),
1117                                 inode, ceph_ino(inode));
1118                         ci->i_flushing_caps = 0;
1119                         list_del_init(&ci->i_flushing_item);
1120                         mdsc->num_cap_flushing--;
1121                         drop = 1;
1122                 }
1123                 if (drop && ci->i_wrbuffer_ref) {
1124                         pr_info(" dropping dirty data for %p %lld\n",
1125                                 inode, ceph_ino(inode));
1126                         ci->i_wrbuffer_ref = 0;
1127                         ci->i_wrbuffer_ref_head = 0;
1128                         drop++;
1129                 }
1130                 spin_unlock(&mdsc->cap_dirty_lock);
1131         }
1132         spin_unlock(&ci->i_ceph_lock);
1133         while (drop--)
1134                 iput(inode);
1135         return 0;
1136 }
1137
1138 /*
1139  * caller must hold session s_mutex
1140  */
1141 static void remove_session_caps(struct ceph_mds_session *session)
1142 {
1143         dout("remove_session_caps on %p\n", session);
1144         iterate_session_caps(session, remove_session_caps_cb, NULL);
1145
1146         spin_lock(&session->s_cap_lock);
1147         if (session->s_nr_caps > 0) {
1148                 struct super_block *sb = session->s_mdsc->fsc->sb;
1149                 struct inode *inode;
1150                 struct ceph_cap *cap, *prev = NULL;
1151                 struct ceph_vino vino;
1152                 /*
1153                  * iterate_session_caps() skips inodes that are being
1154                  * deleted, we need to wait until deletions are complete.
1155                  * __wait_on_freeing_inode() is designed for the job,
1156                  * but it is not exported, so use lookup inode function
1157                  * to access it.
1158                  */
1159                 while (!list_empty(&session->s_caps)) {
1160                         cap = list_entry(session->s_caps.next,
1161                                          struct ceph_cap, session_caps);
1162                         if (cap == prev)
1163                                 break;
1164                         prev = cap;
1165                         vino = cap->ci->i_vino;
1166                         spin_unlock(&session->s_cap_lock);
1167
1168                         inode = ceph_find_inode(sb, vino);
1169                         iput(inode);
1170
1171                         spin_lock(&session->s_cap_lock);
1172                 }
1173         }
1174         spin_unlock(&session->s_cap_lock);
1175
1176         BUG_ON(session->s_nr_caps > 0);
1177         BUG_ON(!list_empty(&session->s_cap_flushing));
1178         cleanup_cap_releases(session);
1179 }
1180
1181 /*
1182  * wake up any threads waiting on this session's caps.  if the cap is
1183  * old (didn't get renewed on the client reconnect), remove it now.
1184  *
1185  * caller must hold s_mutex.
1186  */
1187 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1188                               void *arg)
1189 {
1190         struct ceph_inode_info *ci = ceph_inode(inode);
1191
1192         wake_up_all(&ci->i_cap_wq);
1193         if (arg) {
1194                 spin_lock(&ci->i_ceph_lock);
1195                 ci->i_wanted_max_size = 0;
1196                 ci->i_requested_max_size = 0;
1197                 spin_unlock(&ci->i_ceph_lock);
1198         }
1199         return 0;
1200 }
1201
1202 static void wake_up_session_caps(struct ceph_mds_session *session,
1203                                  int reconnect)
1204 {
1205         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1206         iterate_session_caps(session, wake_up_session_cb,
1207                              (void *)(unsigned long)reconnect);
1208 }
1209
1210 /*
1211  * Send periodic message to MDS renewing all currently held caps.  The
1212  * ack will reset the expiration for all caps from this session.
1213  *
1214  * caller holds s_mutex
1215  */
1216 static int send_renew_caps(struct ceph_mds_client *mdsc,
1217                            struct ceph_mds_session *session)
1218 {
1219         struct ceph_msg *msg;
1220         int state;
1221
1222         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1223             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1224                 pr_info("mds%d caps stale\n", session->s_mds);
1225         session->s_renew_requested = jiffies;
1226
1227         /* do not try to renew caps until a recovering mds has reconnected
1228          * with its clients. */
1229         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1230         if (state < CEPH_MDS_STATE_RECONNECT) {
1231                 dout("send_renew_caps ignoring mds%d (%s)\n",
1232                      session->s_mds, ceph_mds_state_name(state));
1233                 return 0;
1234         }
1235
1236         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1237                 ceph_mds_state_name(state));
1238         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1239                                  ++session->s_renew_seq);
1240         if (!msg)
1241                 return -ENOMEM;
1242         ceph_con_send(&session->s_con, msg);
1243         return 0;
1244 }
1245
1246 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1247                              struct ceph_mds_session *session, u64 seq)
1248 {
1249         struct ceph_msg *msg;
1250
1251         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1252              session->s_mds, ceph_session_state_name(session->s_state), seq);
1253         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1254         if (!msg)
1255                 return -ENOMEM;
1256         ceph_con_send(&session->s_con, msg);
1257         return 0;
1258 }
1259
1260
1261 /*
1262  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1263  *
1264  * Called under session->s_mutex
1265  */
1266 static void renewed_caps(struct ceph_mds_client *mdsc,
1267                          struct ceph_mds_session *session, int is_renew)
1268 {
1269         int was_stale;
1270         int wake = 0;
1271
1272         spin_lock(&session->s_cap_lock);
1273         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1274
1275         session->s_cap_ttl = session->s_renew_requested +
1276                 mdsc->mdsmap->m_session_timeout*HZ;
1277
1278         if (was_stale) {
1279                 if (time_before(jiffies, session->s_cap_ttl)) {
1280                         pr_info("mds%d caps renewed\n", session->s_mds);
1281                         wake = 1;
1282                 } else {
1283                         pr_info("mds%d caps still stale\n", session->s_mds);
1284                 }
1285         }
1286         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1287              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1288              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1289         spin_unlock(&session->s_cap_lock);
1290
1291         if (wake)
1292                 wake_up_session_caps(session, 0);
1293 }
1294
1295 /*
1296  * send a session close request
1297  */
1298 static int request_close_session(struct ceph_mds_client *mdsc,
1299                                  struct ceph_mds_session *session)
1300 {
1301         struct ceph_msg *msg;
1302
1303         dout("request_close_session mds%d state %s seq %lld\n",
1304              session->s_mds, ceph_session_state_name(session->s_state),
1305              session->s_seq);
1306         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1307         if (!msg)
1308                 return -ENOMEM;
1309         ceph_con_send(&session->s_con, msg);
1310         return 0;
1311 }
1312
1313 /*
1314  * Called with s_mutex held.
1315  */
1316 static int __close_session(struct ceph_mds_client *mdsc,
1317                          struct ceph_mds_session *session)
1318 {
1319         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1320                 return 0;
1321         session->s_state = CEPH_MDS_SESSION_CLOSING;
1322         return request_close_session(mdsc, session);
1323 }
1324
1325 /*
1326  * Trim old(er) caps.
1327  *
1328  * Because we can't cache an inode without one or more caps, we do
1329  * this indirectly: if a cap is unused, we prune its aliases, at which
1330  * point the inode will hopefully get dropped to.
1331  *
1332  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1333  * memory pressure from the MDS, though, so it needn't be perfect.
1334  */
1335 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1336 {
1337         struct ceph_mds_session *session = arg;
1338         struct ceph_inode_info *ci = ceph_inode(inode);
1339         int used, wanted, oissued, mine;
1340
1341         if (session->s_trim_caps <= 0)
1342                 return -1;
1343
1344         spin_lock(&ci->i_ceph_lock);
1345         mine = cap->issued | cap->implemented;
1346         used = __ceph_caps_used(ci);
1347         wanted = __ceph_caps_file_wanted(ci);
1348         oissued = __ceph_caps_issued_other(ci, cap);
1349
1350         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1351              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1352              ceph_cap_string(used), ceph_cap_string(wanted));
1353         if (cap == ci->i_auth_cap) {
1354                 if (ci->i_dirty_caps | ci->i_flushing_caps)
1355                         goto out;
1356                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1357                         goto out;
1358         }
1359         if ((used | wanted) & ~oissued & mine)
1360                 goto out;   /* we need these caps */
1361
1362         session->s_trim_caps--;
1363         if (oissued) {
1364                 /* we aren't the only cap.. just remove us */
1365                 __ceph_remove_cap(cap, true);
1366         } else {
1367                 /* try to drop referring dentries */
1368                 spin_unlock(&ci->i_ceph_lock);
1369                 d_prune_aliases(inode);
1370                 dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1371                      inode, cap, atomic_read(&inode->i_count));
1372                 return 0;
1373         }
1374
1375 out:
1376         spin_unlock(&ci->i_ceph_lock);
1377         return 0;
1378 }
1379
1380 /*
1381  * Trim session cap count down to some max number.
1382  */
1383 static int trim_caps(struct ceph_mds_client *mdsc,
1384                      struct ceph_mds_session *session,
1385                      int max_caps)
1386 {
1387         int trim_caps = session->s_nr_caps - max_caps;
1388
1389         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1390              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1391         if (trim_caps > 0) {
1392                 session->s_trim_caps = trim_caps;
1393                 iterate_session_caps(session, trim_caps_cb, session);
1394                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1395                      session->s_mds, session->s_nr_caps, max_caps,
1396                         trim_caps - session->s_trim_caps);
1397                 session->s_trim_caps = 0;
1398         }
1399
1400         ceph_add_cap_releases(mdsc, session);
1401         ceph_send_cap_releases(mdsc, session);
1402         return 0;
1403 }
1404
1405 /*
1406  * Allocate cap_release messages.  If there is a partially full message
1407  * in the queue, try to allocate enough to cover it's remainder, so that
1408  * we can send it immediately.
1409  *
1410  * Called under s_mutex.
1411  */
1412 int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
1413                           struct ceph_mds_session *session)
1414 {
1415         struct ceph_msg *msg, *partial = NULL;
1416         struct ceph_mds_cap_release *head;
1417         int err = -ENOMEM;
1418         int extra = mdsc->fsc->mount_options->cap_release_safety;
1419         int num;
1420
1421         dout("add_cap_releases %p mds%d extra %d\n", session, session->s_mds,
1422              extra);
1423
1424         spin_lock(&session->s_cap_lock);
1425
1426         if (!list_empty(&session->s_cap_releases)) {
1427                 msg = list_first_entry(&session->s_cap_releases,
1428                                        struct ceph_msg,
1429                                  list_head);
1430                 head = msg->front.iov_base;
1431                 num = le32_to_cpu(head->num);
1432                 if (num) {
1433                         dout(" partial %p with (%d/%d)\n", msg, num,
1434                              (int)CEPH_CAPS_PER_RELEASE);
1435                         extra += CEPH_CAPS_PER_RELEASE - num;
1436                         partial = msg;
1437                 }
1438         }
1439         while (session->s_num_cap_releases < session->s_nr_caps + extra) {
1440                 spin_unlock(&session->s_cap_lock);
1441                 msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE, PAGE_CACHE_SIZE,
1442                                    GFP_NOFS, false);
1443                 if (!msg)
1444                         goto out_unlocked;
1445                 dout("add_cap_releases %p msg %p now %d\n", session, msg,
1446                      (int)msg->front.iov_len);
1447                 head = msg->front.iov_base;
1448                 head->num = cpu_to_le32(0);
1449                 msg->front.iov_len = sizeof(*head);
1450                 spin_lock(&session->s_cap_lock);
1451                 list_add(&msg->list_head, &session->s_cap_releases);
1452                 session->s_num_cap_releases += CEPH_CAPS_PER_RELEASE;
1453         }
1454
1455         if (partial) {
1456                 head = partial->front.iov_base;
1457                 num = le32_to_cpu(head->num);
1458                 dout(" queueing partial %p with %d/%d\n", partial, num,
1459                      (int)CEPH_CAPS_PER_RELEASE);
1460                 list_move_tail(&partial->list_head,
1461                                &session->s_cap_releases_done);
1462                 session->s_num_cap_releases -= CEPH_CAPS_PER_RELEASE - num;
1463         }
1464         err = 0;
1465         spin_unlock(&session->s_cap_lock);
1466 out_unlocked:
1467         return err;
1468 }
1469
1470 static int check_cap_flush(struct inode *inode, u64 want_flush_seq)
1471 {
1472         struct ceph_inode_info *ci = ceph_inode(inode);
1473         int ret;
1474         spin_lock(&ci->i_ceph_lock);
1475         if (ci->i_flushing_caps)
1476                 ret = ci->i_cap_flush_seq >= want_flush_seq;
1477         else
1478                 ret = 1;
1479         spin_unlock(&ci->i_ceph_lock);
1480         return ret;
1481 }
1482
1483 /*
1484  * flush all dirty inode data to disk.
1485  *
1486  * returns true if we've flushed through want_flush_seq
1487  */
1488 static void wait_caps_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq)
1489 {
1490         int mds;
1491
1492         dout("check_cap_flush want %lld\n", want_flush_seq);
1493         mutex_lock(&mdsc->mutex);
1494         for (mds = 0; mds < mdsc->max_sessions; mds++) {
1495                 struct ceph_mds_session *session = mdsc->sessions[mds];
1496                 struct inode *inode = NULL;
1497
1498                 if (!session)
1499                         continue;
1500                 get_session(session);
1501                 mutex_unlock(&mdsc->mutex);
1502
1503                 mutex_lock(&session->s_mutex);
1504                 if (!list_empty(&session->s_cap_flushing)) {
1505                         struct ceph_inode_info *ci =
1506                                 list_entry(session->s_cap_flushing.next,
1507                                            struct ceph_inode_info,
1508                                            i_flushing_item);
1509
1510                         if (!check_cap_flush(&ci->vfs_inode, want_flush_seq)) {
1511                                 dout("check_cap_flush still flushing %p "
1512                                      "seq %lld <= %lld to mds%d\n",
1513                                      &ci->vfs_inode, ci->i_cap_flush_seq,
1514                                      want_flush_seq, session->s_mds);
1515                                 inode = igrab(&ci->vfs_inode);
1516                         }
1517                 }
1518                 mutex_unlock(&session->s_mutex);
1519                 ceph_put_mds_session(session);
1520
1521                 if (inode) {
1522                         wait_event(mdsc->cap_flushing_wq,
1523                                    check_cap_flush(inode, want_flush_seq));
1524                         iput(inode);
1525                 }
1526
1527                 mutex_lock(&mdsc->mutex);
1528         }
1529
1530         mutex_unlock(&mdsc->mutex);
1531         dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq);
1532 }
1533
1534 /*
1535  * called under s_mutex
1536  */
1537 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1538                             struct ceph_mds_session *session)
1539 {
1540         struct ceph_msg *msg;
1541
1542         dout("send_cap_releases mds%d\n", session->s_mds);
1543         spin_lock(&session->s_cap_lock);
1544         while (!list_empty(&session->s_cap_releases_done)) {
1545                 msg = list_first_entry(&session->s_cap_releases_done,
1546                                  struct ceph_msg, list_head);
1547                 list_del_init(&msg->list_head);
1548                 spin_unlock(&session->s_cap_lock);
1549                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1550                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1551                 ceph_con_send(&session->s_con, msg);
1552                 spin_lock(&session->s_cap_lock);
1553         }
1554         spin_unlock(&session->s_cap_lock);
1555 }
1556
1557 static void discard_cap_releases(struct ceph_mds_client *mdsc,
1558                                  struct ceph_mds_session *session)
1559 {
1560         struct ceph_msg *msg;
1561         struct ceph_mds_cap_release *head;
1562         unsigned num;
1563
1564         dout("discard_cap_releases mds%d\n", session->s_mds);
1565
1566         if (!list_empty(&session->s_cap_releases)) {
1567                 /* zero out the in-progress message */
1568                 msg = list_first_entry(&session->s_cap_releases,
1569                                         struct ceph_msg, list_head);
1570                 head = msg->front.iov_base;
1571                 num = le32_to_cpu(head->num);
1572                 dout("discard_cap_releases mds%d %p %u\n",
1573                      session->s_mds, msg, num);
1574                 head->num = cpu_to_le32(0);
1575                 msg->front.iov_len = sizeof(*head);
1576                 session->s_num_cap_releases += num;
1577         }
1578
1579         /* requeue completed messages */
1580         while (!list_empty(&session->s_cap_releases_done)) {
1581                 msg = list_first_entry(&session->s_cap_releases_done,
1582                                  struct ceph_msg, list_head);
1583                 list_del_init(&msg->list_head);
1584
1585                 head = msg->front.iov_base;
1586                 num = le32_to_cpu(head->num);
1587                 dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg,
1588                      num);
1589                 session->s_num_cap_releases += num;
1590                 head->num = cpu_to_le32(0);
1591                 msg->front.iov_len = sizeof(*head);
1592                 list_add(&msg->list_head, &session->s_cap_releases);
1593         }
1594 }
1595
1596 /*
1597  * requests
1598  */
1599
1600 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1601                                     struct inode *dir)
1602 {
1603         struct ceph_inode_info *ci = ceph_inode(dir);
1604         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1605         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1606         size_t size = sizeof(*rinfo->dir_in) + sizeof(*rinfo->dir_dname_len) +
1607                       sizeof(*rinfo->dir_dname) + sizeof(*rinfo->dir_dlease);
1608         int order, num_entries;
1609
1610         spin_lock(&ci->i_ceph_lock);
1611         num_entries = ci->i_files + ci->i_subdirs;
1612         spin_unlock(&ci->i_ceph_lock);
1613         num_entries = max(num_entries, 1);
1614         num_entries = min(num_entries, opt->max_readdir);
1615
1616         order = get_order(size * num_entries);
1617         while (order >= 0) {
1618                 rinfo->dir_in = (void*)__get_free_pages(GFP_NOFS | __GFP_NOWARN,
1619                                                         order);
1620                 if (rinfo->dir_in)
1621                         break;
1622                 order--;
1623         }
1624         if (!rinfo->dir_in)
1625                 return -ENOMEM;
1626
1627         num_entries = (PAGE_SIZE << order) / size;
1628         num_entries = min(num_entries, opt->max_readdir);
1629
1630         rinfo->dir_buf_size = PAGE_SIZE << order;
1631         req->r_num_caps = num_entries + 1;
1632         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1633         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1634         return 0;
1635 }
1636
1637 /*
1638  * Create an mds request.
1639  */
1640 struct ceph_mds_request *
1641 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1642 {
1643         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1644
1645         if (!req)
1646                 return ERR_PTR(-ENOMEM);
1647
1648         mutex_init(&req->r_fill_mutex);
1649         req->r_mdsc = mdsc;
1650         req->r_started = jiffies;
1651         req->r_resend_mds = -1;
1652         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1653         req->r_fmode = -1;
1654         kref_init(&req->r_kref);
1655         INIT_LIST_HEAD(&req->r_wait);
1656         init_completion(&req->r_completion);
1657         init_completion(&req->r_safe_completion);
1658         INIT_LIST_HEAD(&req->r_unsafe_item);
1659
1660         req->r_stamp = CURRENT_TIME;
1661
1662         req->r_op = op;
1663         req->r_direct_mode = mode;
1664         return req;
1665 }
1666
1667 /*
1668  * return oldest (lowest) request, tid in request tree, 0 if none.
1669  *
1670  * called under mdsc->mutex.
1671  */
1672 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1673 {
1674         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1675                 return NULL;
1676         return rb_entry(rb_first(&mdsc->request_tree),
1677                         struct ceph_mds_request, r_node);
1678 }
1679
1680 static u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1681 {
1682         struct ceph_mds_request *req = __get_oldest_req(mdsc);
1683
1684         if (req)
1685                 return req->r_tid;
1686         return 0;
1687 }
1688
1689 /*
1690  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1691  * on build_path_from_dentry in fs/cifs/dir.c.
1692  *
1693  * If @stop_on_nosnap, generate path relative to the first non-snapped
1694  * inode.
1695  *
1696  * Encode hidden .snap dirs as a double /, i.e.
1697  *   foo/.snap/bar -> foo//bar
1698  */
1699 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1700                            int stop_on_nosnap)
1701 {
1702         struct dentry *temp;
1703         char *path;
1704         int len, pos;
1705         unsigned seq;
1706
1707         if (dentry == NULL)
1708                 return ERR_PTR(-EINVAL);
1709
1710 retry:
1711         len = 0;
1712         seq = read_seqbegin(&rename_lock);
1713         rcu_read_lock();
1714         for (temp = dentry; !IS_ROOT(temp);) {
1715                 struct inode *inode = d_inode(temp);
1716                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1717                         len++;  /* slash only */
1718                 else if (stop_on_nosnap && inode &&
1719                          ceph_snap(inode) == CEPH_NOSNAP)
1720                         break;
1721                 else
1722                         len += 1 + temp->d_name.len;
1723                 temp = temp->d_parent;
1724         }
1725         rcu_read_unlock();
1726         if (len)
1727                 len--;  /* no leading '/' */
1728
1729         path = kmalloc(len+1, GFP_NOFS);
1730         if (path == NULL)
1731                 return ERR_PTR(-ENOMEM);
1732         pos = len;
1733         path[pos] = 0;  /* trailing null */
1734         rcu_read_lock();
1735         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1736                 struct inode *inode;
1737
1738                 spin_lock(&temp->d_lock);
1739                 inode = d_inode(temp);
1740                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1741                         dout("build_path path+%d: %p SNAPDIR\n",
1742                              pos, temp);
1743                 } else if (stop_on_nosnap && inode &&
1744                            ceph_snap(inode) == CEPH_NOSNAP) {
1745                         spin_unlock(&temp->d_lock);
1746                         break;
1747                 } else {
1748                         pos -= temp->d_name.len;
1749                         if (pos < 0) {
1750                                 spin_unlock(&temp->d_lock);
1751                                 break;
1752                         }
1753                         strncpy(path + pos, temp->d_name.name,
1754                                 temp->d_name.len);
1755                 }
1756                 spin_unlock(&temp->d_lock);
1757                 if (pos)
1758                         path[--pos] = '/';
1759                 temp = temp->d_parent;
1760         }
1761         rcu_read_unlock();
1762         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1763                 pr_err("build_path did not end path lookup where "
1764                        "expected, namelen is %d, pos is %d\n", len, pos);
1765                 /* presumably this is only possible if racing with a
1766                    rename of one of the parent directories (we can not
1767                    lock the dentries above us to prevent this, but
1768                    retrying should be harmless) */
1769                 kfree(path);
1770                 goto retry;
1771         }
1772
1773         *base = ceph_ino(d_inode(temp));
1774         *plen = len;
1775         dout("build_path on %p %d built %llx '%.*s'\n",
1776              dentry, d_count(dentry), *base, len, path);
1777         return path;
1778 }
1779
1780 static int build_dentry_path(struct dentry *dentry,
1781                              const char **ppath, int *ppathlen, u64 *pino,
1782                              int *pfreepath)
1783 {
1784         char *path;
1785
1786         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP) {
1787                 *pino = ceph_ino(d_inode(dentry->d_parent));
1788                 *ppath = dentry->d_name.name;
1789                 *ppathlen = dentry->d_name.len;
1790                 return 0;
1791         }
1792         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1793         if (IS_ERR(path))
1794                 return PTR_ERR(path);
1795         *ppath = path;
1796         *pfreepath = 1;
1797         return 0;
1798 }
1799
1800 static int build_inode_path(struct inode *inode,
1801                             const char **ppath, int *ppathlen, u64 *pino,
1802                             int *pfreepath)
1803 {
1804         struct dentry *dentry;
1805         char *path;
1806
1807         if (ceph_snap(inode) == CEPH_NOSNAP) {
1808                 *pino = ceph_ino(inode);
1809                 *ppathlen = 0;
1810                 return 0;
1811         }
1812         dentry = d_find_alias(inode);
1813         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1814         dput(dentry);
1815         if (IS_ERR(path))
1816                 return PTR_ERR(path);
1817         *ppath = path;
1818         *pfreepath = 1;
1819         return 0;
1820 }
1821
1822 /*
1823  * request arguments may be specified via an inode *, a dentry *, or
1824  * an explicit ino+path.
1825  */
1826 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1827                                   const char *rpath, u64 rino,
1828                                   const char **ppath, int *pathlen,
1829                                   u64 *ino, int *freepath)
1830 {
1831         int r = 0;
1832
1833         if (rinode) {
1834                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1835                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1836                      ceph_snap(rinode));
1837         } else if (rdentry) {
1838                 r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1839                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1840                      *ppath);
1841         } else if (rpath || rino) {
1842                 *ino = rino;
1843                 *ppath = rpath;
1844                 *pathlen = rpath ? strlen(rpath) : 0;
1845                 dout(" path %.*s\n", *pathlen, rpath);
1846         }
1847
1848         return r;
1849 }
1850
1851 /*
1852  * called under mdsc->mutex
1853  */
1854 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1855                                                struct ceph_mds_request *req,
1856                                                int mds)
1857 {
1858         struct ceph_msg *msg;
1859         struct ceph_mds_request_head *head;
1860         const char *path1 = NULL;
1861         const char *path2 = NULL;
1862         u64 ino1 = 0, ino2 = 0;
1863         int pathlen1 = 0, pathlen2 = 0;
1864         int freepath1 = 0, freepath2 = 0;
1865         int len;
1866         u16 releases;
1867         void *p, *end;
1868         int ret;
1869
1870         ret = set_request_path_attr(req->r_inode, req->r_dentry,
1871                               req->r_path1, req->r_ino1.ino,
1872                               &path1, &pathlen1, &ino1, &freepath1);
1873         if (ret < 0) {
1874                 msg = ERR_PTR(ret);
1875                 goto out;
1876         }
1877
1878         ret = set_request_path_attr(NULL, req->r_old_dentry,
1879                               req->r_path2, req->r_ino2.ino,
1880                               &path2, &pathlen2, &ino2, &freepath2);
1881         if (ret < 0) {
1882                 msg = ERR_PTR(ret);
1883                 goto out_free1;
1884         }
1885
1886         len = sizeof(*head) +
1887                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1888                 sizeof(struct timespec);
1889
1890         /* calculate (max) length for cap releases */
1891         len += sizeof(struct ceph_mds_request_release) *
1892                 (!!req->r_inode_drop + !!req->r_dentry_drop +
1893                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1894         if (req->r_dentry_drop)
1895                 len += req->r_dentry->d_name.len;
1896         if (req->r_old_dentry_drop)
1897                 len += req->r_old_dentry->d_name.len;
1898
1899         msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1900         if (!msg) {
1901                 msg = ERR_PTR(-ENOMEM);
1902                 goto out_free2;
1903         }
1904
1905         msg->hdr.version = cpu_to_le16(2);
1906         msg->hdr.tid = cpu_to_le64(req->r_tid);
1907
1908         head = msg->front.iov_base;
1909         p = msg->front.iov_base + sizeof(*head);
1910         end = msg->front.iov_base + msg->front.iov_len;
1911
1912         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1913         head->op = cpu_to_le32(req->r_op);
1914         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1915         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1916         head->args = req->r_args;
1917
1918         ceph_encode_filepath(&p, end, ino1, path1);
1919         ceph_encode_filepath(&p, end, ino2, path2);
1920
1921         /* make note of release offset, in case we need to replay */
1922         req->r_request_release_offset = p - msg->front.iov_base;
1923
1924         /* cap releases */
1925         releases = 0;
1926         if (req->r_inode_drop)
1927                 releases += ceph_encode_inode_release(&p,
1928                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
1929                       mds, req->r_inode_drop, req->r_inode_unless, 0);
1930         if (req->r_dentry_drop)
1931                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
1932                        mds, req->r_dentry_drop, req->r_dentry_unless);
1933         if (req->r_old_dentry_drop)
1934                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1935                        mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1936         if (req->r_old_inode_drop)
1937                 releases += ceph_encode_inode_release(&p,
1938                       d_inode(req->r_old_dentry),
1939                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1940         head->num_releases = cpu_to_le16(releases);
1941
1942         /* time stamp */
1943         {
1944                 struct ceph_timespec ts;
1945                 ceph_encode_timespec(&ts, &req->r_stamp);
1946                 ceph_encode_copy(&p, &ts, sizeof(ts));
1947         }
1948
1949         BUG_ON(p > end);
1950         msg->front.iov_len = p - msg->front.iov_base;
1951         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1952
1953         if (req->r_pagelist) {
1954                 struct ceph_pagelist *pagelist = req->r_pagelist;
1955                 atomic_inc(&pagelist->refcnt);
1956                 ceph_msg_data_add_pagelist(msg, pagelist);
1957                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
1958         } else {
1959                 msg->hdr.data_len = 0;
1960         }
1961
1962         msg->hdr.data_off = cpu_to_le16(0);
1963
1964 out_free2:
1965         if (freepath2)
1966                 kfree((char *)path2);
1967 out_free1:
1968         if (freepath1)
1969                 kfree((char *)path1);
1970 out:
1971         return msg;
1972 }
1973
1974 /*
1975  * called under mdsc->mutex if error, under no mutex if
1976  * success.
1977  */
1978 static void complete_request(struct ceph_mds_client *mdsc,
1979                              struct ceph_mds_request *req)
1980 {
1981         if (req->r_callback)
1982                 req->r_callback(mdsc, req);
1983         else
1984                 complete_all(&req->r_completion);
1985 }
1986
1987 /*
1988  * called under mdsc->mutex
1989  */
1990 static int __prepare_send_request(struct ceph_mds_client *mdsc,
1991                                   struct ceph_mds_request *req,
1992                                   int mds)
1993 {
1994         struct ceph_mds_request_head *rhead;
1995         struct ceph_msg *msg;
1996         int flags = 0;
1997
1998         req->r_attempts++;
1999         if (req->r_inode) {
2000                 struct ceph_cap *cap =
2001                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2002
2003                 if (cap)
2004                         req->r_sent_on_mseq = cap->mseq;
2005                 else
2006                         req->r_sent_on_mseq = -1;
2007         }
2008         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2009              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2010
2011         if (req->r_got_unsafe) {
2012                 void *p;
2013                 /*
2014                  * Replay.  Do not regenerate message (and rebuild
2015                  * paths, etc.); just use the original message.
2016                  * Rebuilding paths will break for renames because
2017                  * d_move mangles the src name.
2018                  */
2019                 msg = req->r_request;
2020                 rhead = msg->front.iov_base;
2021
2022                 flags = le32_to_cpu(rhead->flags);
2023                 flags |= CEPH_MDS_FLAG_REPLAY;
2024                 rhead->flags = cpu_to_le32(flags);
2025
2026                 if (req->r_target_inode)
2027                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2028
2029                 rhead->num_retry = req->r_attempts - 1;
2030
2031                 /* remove cap/dentry releases from message */
2032                 rhead->num_releases = 0;
2033
2034                 /* time stamp */
2035                 p = msg->front.iov_base + req->r_request_release_offset;
2036                 {
2037                         struct ceph_timespec ts;
2038                         ceph_encode_timespec(&ts, &req->r_stamp);
2039                         ceph_encode_copy(&p, &ts, sizeof(ts));
2040                 }
2041
2042                 msg->front.iov_len = p - msg->front.iov_base;
2043                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2044                 return 0;
2045         }
2046
2047         if (req->r_request) {
2048                 ceph_msg_put(req->r_request);
2049                 req->r_request = NULL;
2050         }
2051         msg = create_request_message(mdsc, req, mds);
2052         if (IS_ERR(msg)) {
2053                 req->r_err = PTR_ERR(msg);
2054                 complete_request(mdsc, req);
2055                 return PTR_ERR(msg);
2056         }
2057         req->r_request = msg;
2058
2059         rhead = msg->front.iov_base;
2060         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2061         if (req->r_got_unsafe)
2062                 flags |= CEPH_MDS_FLAG_REPLAY;
2063         if (req->r_locked_dir)
2064                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2065         rhead->flags = cpu_to_le32(flags);
2066         rhead->num_fwd = req->r_num_fwd;
2067         rhead->num_retry = req->r_attempts - 1;
2068         rhead->ino = 0;
2069
2070         dout(" r_locked_dir = %p\n", req->r_locked_dir);
2071         return 0;
2072 }
2073
2074 /*
2075  * send request, or put it on the appropriate wait list.
2076  */
2077 static int __do_request(struct ceph_mds_client *mdsc,
2078                         struct ceph_mds_request *req)
2079 {
2080         struct ceph_mds_session *session = NULL;
2081         int mds = -1;
2082         int err = -EAGAIN;
2083
2084         if (req->r_err || req->r_got_result) {
2085                 if (req->r_aborted)
2086                         __unregister_request(mdsc, req);
2087                 goto out;
2088         }
2089
2090         if (req->r_timeout &&
2091             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2092                 dout("do_request timed out\n");
2093                 err = -EIO;
2094                 goto finish;
2095         }
2096
2097         put_request_session(req);
2098
2099         mds = __choose_mds(mdsc, req);
2100         if (mds < 0 ||
2101             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2102                 dout("do_request no mds or not active, waiting for map\n");
2103                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2104                 goto out;
2105         }
2106
2107         /* get, open session */
2108         session = __ceph_lookup_mds_session(mdsc, mds);
2109         if (!session) {
2110                 session = register_session(mdsc, mds);
2111                 if (IS_ERR(session)) {
2112                         err = PTR_ERR(session);
2113                         goto finish;
2114                 }
2115         }
2116         req->r_session = get_session(session);
2117
2118         dout("do_request mds%d session %p state %s\n", mds, session,
2119              ceph_session_state_name(session->s_state));
2120         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2121             session->s_state != CEPH_MDS_SESSION_HUNG) {
2122                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2123                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2124                         __open_session(mdsc, session);
2125                 list_add(&req->r_wait, &session->s_waiting);
2126                 goto out_session;
2127         }
2128
2129         /* send request */
2130         req->r_resend_mds = -1;   /* forget any previous mds hint */
2131
2132         if (req->r_request_started == 0)   /* note request start time */
2133                 req->r_request_started = jiffies;
2134
2135         err = __prepare_send_request(mdsc, req, mds);
2136         if (!err) {
2137                 ceph_msg_get(req->r_request);
2138                 ceph_con_send(&session->s_con, req->r_request);
2139         }
2140
2141 out_session:
2142         ceph_put_mds_session(session);
2143 out:
2144         return err;
2145
2146 finish:
2147         req->r_err = err;
2148         complete_request(mdsc, req);
2149         goto out;
2150 }
2151
2152 /*
2153  * called under mdsc->mutex
2154  */
2155 static void __wake_requests(struct ceph_mds_client *mdsc,
2156                             struct list_head *head)
2157 {
2158         struct ceph_mds_request *req;
2159         LIST_HEAD(tmp_list);
2160
2161         list_splice_init(head, &tmp_list);
2162
2163         while (!list_empty(&tmp_list)) {
2164                 req = list_entry(tmp_list.next,
2165                                  struct ceph_mds_request, r_wait);
2166                 list_del_init(&req->r_wait);
2167                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2168                 __do_request(mdsc, req);
2169         }
2170 }
2171
2172 /*
2173  * Wake up threads with requests pending for @mds, so that they can
2174  * resubmit their requests to a possibly different mds.
2175  */
2176 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2177 {
2178         struct ceph_mds_request *req;
2179         struct rb_node *p = rb_first(&mdsc->request_tree);
2180
2181         dout("kick_requests mds%d\n", mds);
2182         while (p) {
2183                 req = rb_entry(p, struct ceph_mds_request, r_node);
2184                 p = rb_next(p);
2185                 if (req->r_got_unsafe)
2186                         continue;
2187                 if (req->r_attempts > 0)
2188                         continue; /* only new requests */
2189                 if (req->r_session &&
2190                     req->r_session->s_mds == mds) {
2191                         dout(" kicking tid %llu\n", req->r_tid);
2192                         list_del_init(&req->r_wait);
2193                         __do_request(mdsc, req);
2194                 }
2195         }
2196 }
2197
2198 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2199                               struct ceph_mds_request *req)
2200 {
2201         dout("submit_request on %p\n", req);
2202         mutex_lock(&mdsc->mutex);
2203         __register_request(mdsc, req, NULL);
2204         __do_request(mdsc, req);
2205         mutex_unlock(&mdsc->mutex);
2206 }
2207
2208 /*
2209  * Synchrously perform an mds request.  Take care of all of the
2210  * session setup, forwarding, retry details.
2211  */
2212 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2213                          struct inode *dir,
2214                          struct ceph_mds_request *req)
2215 {
2216         int err;
2217
2218         dout("do_request on %p\n", req);
2219
2220         /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2221         if (req->r_inode)
2222                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2223         if (req->r_locked_dir)
2224                 ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2225         if (req->r_old_dentry_dir)
2226                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2227                                   CEPH_CAP_PIN);
2228
2229         /* issue */
2230         mutex_lock(&mdsc->mutex);
2231         __register_request(mdsc, req, dir);
2232         __do_request(mdsc, req);
2233
2234         if (req->r_err) {
2235                 err = req->r_err;
2236                 __unregister_request(mdsc, req);
2237                 dout("do_request early error %d\n", err);
2238                 goto out;
2239         }
2240
2241         /* wait */
2242         mutex_unlock(&mdsc->mutex);
2243         dout("do_request waiting\n");
2244         if (req->r_timeout) {
2245                 err = (long)wait_for_completion_killable_timeout(
2246                         &req->r_completion, req->r_timeout);
2247                 if (err == 0)
2248                         err = -EIO;
2249         } else if (req->r_wait_for_completion) {
2250                 err = req->r_wait_for_completion(mdsc, req);
2251         } else {
2252                 err = wait_for_completion_killable(&req->r_completion);
2253         }
2254         dout("do_request waited, got %d\n", err);
2255         mutex_lock(&mdsc->mutex);
2256
2257         /* only abort if we didn't race with a real reply */
2258         if (req->r_got_result) {
2259                 err = le32_to_cpu(req->r_reply_info.head->result);
2260         } else if (err < 0) {
2261                 dout("aborted request %lld with %d\n", req->r_tid, err);
2262
2263                 /*
2264                  * ensure we aren't running concurrently with
2265                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2266                  * rely on locks (dir mutex) held by our caller.
2267                  */
2268                 mutex_lock(&req->r_fill_mutex);
2269                 req->r_err = err;
2270                 req->r_aborted = true;
2271                 mutex_unlock(&req->r_fill_mutex);
2272
2273                 if (req->r_locked_dir &&
2274                     (req->r_op & CEPH_MDS_OP_WRITE))
2275                         ceph_invalidate_dir_request(req);
2276         } else {
2277                 err = req->r_err;
2278         }
2279
2280 out:
2281         mutex_unlock(&mdsc->mutex);
2282         dout("do_request %p done, result %d\n", req, err);
2283         return err;
2284 }
2285
2286 /*
2287  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2288  * namespace request.
2289  */
2290 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2291 {
2292         struct inode *inode = req->r_locked_dir;
2293
2294         dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2295
2296         ceph_dir_clear_complete(inode);
2297         if (req->r_dentry)
2298                 ceph_invalidate_dentry_lease(req->r_dentry);
2299         if (req->r_old_dentry)
2300                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2301 }
2302
2303 /*
2304  * Handle mds reply.
2305  *
2306  * We take the session mutex and parse and process the reply immediately.
2307  * This preserves the logical ordering of replies, capabilities, etc., sent
2308  * by the MDS as they are applied to our local cache.
2309  */
2310 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2311 {
2312         struct ceph_mds_client *mdsc = session->s_mdsc;
2313         struct ceph_mds_request *req;
2314         struct ceph_mds_reply_head *head = msg->front.iov_base;
2315         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2316         struct ceph_snap_realm *realm;
2317         u64 tid;
2318         int err, result;
2319         int mds = session->s_mds;
2320
2321         if (msg->front.iov_len < sizeof(*head)) {
2322                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2323                 ceph_msg_dump(msg);
2324                 return;
2325         }
2326
2327         /* get request, session */
2328         tid = le64_to_cpu(msg->hdr.tid);
2329         mutex_lock(&mdsc->mutex);
2330         req = __lookup_request(mdsc, tid);
2331         if (!req) {
2332                 dout("handle_reply on unknown tid %llu\n", tid);
2333                 mutex_unlock(&mdsc->mutex);
2334                 return;
2335         }
2336         dout("handle_reply %p\n", req);
2337
2338         /* correct session? */
2339         if (req->r_session != session) {
2340                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2341                        " not mds%d\n", tid, session->s_mds,
2342                        req->r_session ? req->r_session->s_mds : -1);
2343                 mutex_unlock(&mdsc->mutex);
2344                 goto out;
2345         }
2346
2347         /* dup? */
2348         if ((req->r_got_unsafe && !head->safe) ||
2349             (req->r_got_safe && head->safe)) {
2350                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2351                            head->safe ? "safe" : "unsafe", tid, mds);
2352                 mutex_unlock(&mdsc->mutex);
2353                 goto out;
2354         }
2355         if (req->r_got_safe && !head->safe) {
2356                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2357                            tid, mds);
2358                 mutex_unlock(&mdsc->mutex);
2359                 goto out;
2360         }
2361
2362         result = le32_to_cpu(head->result);
2363
2364         /*
2365          * Handle an ESTALE
2366          * if we're not talking to the authority, send to them
2367          * if the authority has changed while we weren't looking,
2368          * send to new authority
2369          * Otherwise we just have to return an ESTALE
2370          */
2371         if (result == -ESTALE) {
2372                 dout("got ESTALE on request %llu", req->r_tid);
2373                 req->r_resend_mds = -1;
2374                 if (req->r_direct_mode != USE_AUTH_MDS) {
2375                         dout("not using auth, setting for that now");
2376                         req->r_direct_mode = USE_AUTH_MDS;
2377                         __do_request(mdsc, req);
2378                         mutex_unlock(&mdsc->mutex);
2379                         goto out;
2380                 } else  {
2381                         int mds = __choose_mds(mdsc, req);
2382                         if (mds >= 0 && mds != req->r_session->s_mds) {
2383                                 dout("but auth changed, so resending");
2384                                 __do_request(mdsc, req);
2385                                 mutex_unlock(&mdsc->mutex);
2386                                 goto out;
2387                         }
2388                 }
2389                 dout("have to return ESTALE on request %llu", req->r_tid);
2390         }
2391
2392
2393         if (head->safe) {
2394                 req->r_got_safe = true;
2395                 __unregister_request(mdsc, req);
2396
2397                 if (req->r_got_unsafe) {
2398                         /*
2399                          * We already handled the unsafe response, now do the
2400                          * cleanup.  No need to examine the response; the MDS
2401                          * doesn't include any result info in the safe
2402                          * response.  And even if it did, there is nothing
2403                          * useful we could do with a revised return value.
2404                          */
2405                         dout("got safe reply %llu, mds%d\n", tid, mds);
2406                         list_del_init(&req->r_unsafe_item);
2407
2408                         /* last unsafe request during umount? */
2409                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2410                                 complete_all(&mdsc->safe_umount_waiters);
2411                         mutex_unlock(&mdsc->mutex);
2412                         goto out;
2413                 }
2414         } else {
2415                 req->r_got_unsafe = true;
2416                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2417         }
2418
2419         dout("handle_reply tid %lld result %d\n", tid, result);
2420         rinfo = &req->r_reply_info;
2421         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2422         mutex_unlock(&mdsc->mutex);
2423
2424         mutex_lock(&session->s_mutex);
2425         if (err < 0) {
2426                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2427                 ceph_msg_dump(msg);
2428                 goto out_err;
2429         }
2430
2431         /* snap trace */
2432         realm = NULL;
2433         if (rinfo->snapblob_len) {
2434                 down_write(&mdsc->snap_rwsem);
2435                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2436                                 rinfo->snapblob + rinfo->snapblob_len,
2437                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2438                                 &realm);
2439                 downgrade_write(&mdsc->snap_rwsem);
2440         } else {
2441                 down_read(&mdsc->snap_rwsem);
2442         }
2443
2444         /* insert trace into our cache */
2445         mutex_lock(&req->r_fill_mutex);
2446         err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2447         if (err == 0) {
2448                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2449                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2450                         ceph_readdir_prepopulate(req, req->r_session);
2451                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2452         }
2453         mutex_unlock(&req->r_fill_mutex);
2454
2455         up_read(&mdsc->snap_rwsem);
2456         if (realm)
2457                 ceph_put_snap_realm(mdsc, realm);
2458 out_err:
2459         mutex_lock(&mdsc->mutex);
2460         if (!req->r_aborted) {
2461                 if (err) {
2462                         req->r_err = err;
2463                 } else {
2464                         req->r_reply = msg;
2465                         ceph_msg_get(msg);
2466                         req->r_got_result = true;
2467                 }
2468         } else {
2469                 dout("reply arrived after request %lld was aborted\n", tid);
2470         }
2471         mutex_unlock(&mdsc->mutex);
2472
2473         ceph_add_cap_releases(mdsc, req->r_session);
2474         mutex_unlock(&session->s_mutex);
2475
2476         /* kick calling process */
2477         complete_request(mdsc, req);
2478 out:
2479         ceph_mdsc_put_request(req);
2480         return;
2481 }
2482
2483
2484
2485 /*
2486  * handle mds notification that our request has been forwarded.
2487  */
2488 static void handle_forward(struct ceph_mds_client *mdsc,
2489                            struct ceph_mds_session *session,
2490                            struct ceph_msg *msg)
2491 {
2492         struct ceph_mds_request *req;
2493         u64 tid = le64_to_cpu(msg->hdr.tid);
2494         u32 next_mds;
2495         u32 fwd_seq;
2496         int err = -EINVAL;
2497         void *p = msg->front.iov_base;
2498         void *end = p + msg->front.iov_len;
2499
2500         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2501         next_mds = ceph_decode_32(&p);
2502         fwd_seq = ceph_decode_32(&p);
2503
2504         mutex_lock(&mdsc->mutex);
2505         req = __lookup_request(mdsc, tid);
2506         if (!req) {
2507                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2508                 goto out;  /* dup reply? */
2509         }
2510
2511         if (req->r_aborted) {
2512                 dout("forward tid %llu aborted, unregistering\n", tid);
2513                 __unregister_request(mdsc, req);
2514         } else if (fwd_seq <= req->r_num_fwd) {
2515                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2516                      tid, next_mds, req->r_num_fwd, fwd_seq);
2517         } else {
2518                 /* resend. forward race not possible; mds would drop */
2519                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2520                 BUG_ON(req->r_err);
2521                 BUG_ON(req->r_got_result);
2522                 req->r_attempts = 0;
2523                 req->r_num_fwd = fwd_seq;
2524                 req->r_resend_mds = next_mds;
2525                 put_request_session(req);
2526                 __do_request(mdsc, req);
2527         }
2528         ceph_mdsc_put_request(req);
2529 out:
2530         mutex_unlock(&mdsc->mutex);
2531         return;
2532
2533 bad:
2534         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2535 }
2536
2537 /*
2538  * handle a mds session control message
2539  */
2540 static void handle_session(struct ceph_mds_session *session,
2541                            struct ceph_msg *msg)
2542 {
2543         struct ceph_mds_client *mdsc = session->s_mdsc;
2544         u32 op;
2545         u64 seq;
2546         int mds = session->s_mds;
2547         struct ceph_mds_session_head *h = msg->front.iov_base;
2548         int wake = 0;
2549
2550         /* decode */
2551         if (msg->front.iov_len != sizeof(*h))
2552                 goto bad;
2553         op = le32_to_cpu(h->op);
2554         seq = le64_to_cpu(h->seq);
2555
2556         mutex_lock(&mdsc->mutex);
2557         if (op == CEPH_SESSION_CLOSE)
2558                 __unregister_session(mdsc, session);
2559         /* FIXME: this ttl calculation is generous */
2560         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2561         mutex_unlock(&mdsc->mutex);
2562
2563         mutex_lock(&session->s_mutex);
2564
2565         dout("handle_session mds%d %s %p state %s seq %llu\n",
2566              mds, ceph_session_op_name(op), session,
2567              ceph_session_state_name(session->s_state), seq);
2568
2569         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2570                 session->s_state = CEPH_MDS_SESSION_OPEN;
2571                 pr_info("mds%d came back\n", session->s_mds);
2572         }
2573
2574         switch (op) {
2575         case CEPH_SESSION_OPEN:
2576                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2577                         pr_info("mds%d reconnect success\n", session->s_mds);
2578                 session->s_state = CEPH_MDS_SESSION_OPEN;
2579                 renewed_caps(mdsc, session, 0);
2580                 wake = 1;
2581                 if (mdsc->stopping)
2582                         __close_session(mdsc, session);
2583                 break;
2584
2585         case CEPH_SESSION_RENEWCAPS:
2586                 if (session->s_renew_seq == seq)
2587                         renewed_caps(mdsc, session, 1);
2588                 break;
2589
2590         case CEPH_SESSION_CLOSE:
2591                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2592                         pr_info("mds%d reconnect denied\n", session->s_mds);
2593                 remove_session_caps(session);
2594                 wake = 2; /* for good measure */
2595                 wake_up_all(&mdsc->session_close_wq);
2596                 break;
2597
2598         case CEPH_SESSION_STALE:
2599                 pr_info("mds%d caps went stale, renewing\n",
2600                         session->s_mds);
2601                 spin_lock(&session->s_gen_ttl_lock);
2602                 session->s_cap_gen++;
2603                 session->s_cap_ttl = jiffies - 1;
2604                 spin_unlock(&session->s_gen_ttl_lock);
2605                 send_renew_caps(mdsc, session);
2606                 break;
2607
2608         case CEPH_SESSION_RECALL_STATE:
2609                 trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2610                 break;
2611
2612         case CEPH_SESSION_FLUSHMSG:
2613                 send_flushmsg_ack(mdsc, session, seq);
2614                 break;
2615
2616         case CEPH_SESSION_FORCE_RO:
2617                 dout("force_session_readonly %p\n", session);
2618                 spin_lock(&session->s_cap_lock);
2619                 session->s_readonly = true;
2620                 spin_unlock(&session->s_cap_lock);
2621                 wake_up_session_caps(session, 0);
2622                 break;
2623
2624         default:
2625                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2626                 WARN_ON(1);
2627         }
2628
2629         mutex_unlock(&session->s_mutex);
2630         if (wake) {
2631                 mutex_lock(&mdsc->mutex);
2632                 __wake_requests(mdsc, &session->s_waiting);
2633                 if (wake == 2)
2634                         kick_requests(mdsc, mds);
2635                 mutex_unlock(&mdsc->mutex);
2636         }
2637         return;
2638
2639 bad:
2640         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2641                (int)msg->front.iov_len);
2642         ceph_msg_dump(msg);
2643         return;
2644 }
2645
2646
2647 /*
2648  * called under session->mutex.
2649  */
2650 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2651                                    struct ceph_mds_session *session)
2652 {
2653         struct ceph_mds_request *req, *nreq;
2654         struct rb_node *p;
2655         int err;
2656
2657         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2658
2659         mutex_lock(&mdsc->mutex);
2660         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2661                 err = __prepare_send_request(mdsc, req, session->s_mds);
2662                 if (!err) {
2663                         ceph_msg_get(req->r_request);
2664                         ceph_con_send(&session->s_con, req->r_request);
2665                 }
2666         }
2667
2668         /*
2669          * also re-send old requests when MDS enters reconnect stage. So that MDS
2670          * can process completed request in clientreplay stage.
2671          */
2672         p = rb_first(&mdsc->request_tree);
2673         while (p) {
2674                 req = rb_entry(p, struct ceph_mds_request, r_node);
2675                 p = rb_next(p);
2676                 if (req->r_got_unsafe)
2677                         continue;
2678                 if (req->r_attempts == 0)
2679                         continue; /* only old requests */
2680                 if (req->r_session &&
2681                     req->r_session->s_mds == session->s_mds) {
2682                         err = __prepare_send_request(mdsc, req, session->s_mds);
2683                         if (!err) {
2684                                 ceph_msg_get(req->r_request);
2685                                 ceph_con_send(&session->s_con, req->r_request);
2686                         }
2687                 }
2688         }
2689         mutex_unlock(&mdsc->mutex);
2690 }
2691
2692 /*
2693  * Encode information about a cap for a reconnect with the MDS.
2694  */
2695 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2696                           void *arg)
2697 {
2698         union {
2699                 struct ceph_mds_cap_reconnect v2;
2700                 struct ceph_mds_cap_reconnect_v1 v1;
2701         } rec;
2702         size_t reclen;
2703         struct ceph_inode_info *ci;
2704         struct ceph_reconnect_state *recon_state = arg;
2705         struct ceph_pagelist *pagelist = recon_state->pagelist;
2706         char *path;
2707         int pathlen, err;
2708         u64 pathbase;
2709         struct dentry *dentry;
2710
2711         ci = cap->ci;
2712
2713         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2714              inode, ceph_vinop(inode), cap, cap->cap_id,
2715              ceph_cap_string(cap->issued));
2716         err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2717         if (err)
2718                 return err;
2719
2720         dentry = d_find_alias(inode);
2721         if (dentry) {
2722                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2723                 if (IS_ERR(path)) {
2724                         err = PTR_ERR(path);
2725                         goto out_dput;
2726                 }
2727         } else {
2728                 path = NULL;
2729                 pathlen = 0;
2730         }
2731         err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2732         if (err)
2733                 goto out_free;
2734
2735         spin_lock(&ci->i_ceph_lock);
2736         cap->seq = 0;        /* reset cap seq */
2737         cap->issue_seq = 0;  /* and issue_seq */
2738         cap->mseq = 0;       /* and migrate_seq */
2739         cap->cap_gen = cap->session->s_cap_gen;
2740
2741         if (recon_state->flock) {
2742                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2743                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2744                 rec.v2.issued = cpu_to_le32(cap->issued);
2745                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2746                 rec.v2.pathbase = cpu_to_le64(pathbase);
2747                 rec.v2.flock_len = 0;
2748                 reclen = sizeof(rec.v2);
2749         } else {
2750                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2751                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2752                 rec.v1.issued = cpu_to_le32(cap->issued);
2753                 rec.v1.size = cpu_to_le64(inode->i_size);
2754                 ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2755                 ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2756                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2757                 rec.v1.pathbase = cpu_to_le64(pathbase);
2758                 reclen = sizeof(rec.v1);
2759         }
2760         spin_unlock(&ci->i_ceph_lock);
2761
2762         if (recon_state->flock) {
2763                 int num_fcntl_locks, num_flock_locks;
2764                 struct ceph_filelock *flocks;
2765
2766 encode_again:
2767                 ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2768                 flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2769                                  sizeof(struct ceph_filelock), GFP_NOFS);
2770                 if (!flocks) {
2771                         err = -ENOMEM;
2772                         goto out_free;
2773                 }
2774                 err = ceph_encode_locks_to_buffer(inode, flocks,
2775                                                   num_fcntl_locks,
2776                                                   num_flock_locks);
2777                 if (err) {
2778                         kfree(flocks);
2779                         if (err == -ENOSPC)
2780                                 goto encode_again;
2781                         goto out_free;
2782                 }
2783                 /*
2784                  * number of encoded locks is stable, so copy to pagelist
2785                  */
2786                 rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2787                                     (num_fcntl_locks+num_flock_locks) *
2788                                     sizeof(struct ceph_filelock));
2789                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2790                 if (!err)
2791                         err = ceph_locks_to_pagelist(flocks, pagelist,
2792                                                      num_fcntl_locks,
2793                                                      num_flock_locks);
2794                 kfree(flocks);
2795         } else {
2796                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2797         }
2798
2799         recon_state->nr_caps++;
2800 out_free:
2801         kfree(path);
2802 out_dput:
2803         dput(dentry);
2804         return err;
2805 }
2806
2807
2808 /*
2809  * If an MDS fails and recovers, clients need to reconnect in order to
2810  * reestablish shared state.  This includes all caps issued through
2811  * this session _and_ the snap_realm hierarchy.  Because it's not
2812  * clear which snap realms the mds cares about, we send everything we
2813  * know about.. that ensures we'll then get any new info the
2814  * recovering MDS might have.
2815  *
2816  * This is a relatively heavyweight operation, but it's rare.
2817  *
2818  * called with mdsc->mutex held.
2819  */
2820 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2821                                struct ceph_mds_session *session)
2822 {
2823         struct ceph_msg *reply;
2824         struct rb_node *p;
2825         int mds = session->s_mds;
2826         int err = -ENOMEM;
2827         int s_nr_caps;
2828         struct ceph_pagelist *pagelist;
2829         struct ceph_reconnect_state recon_state;
2830
2831         pr_info("mds%d reconnect start\n", mds);
2832
2833         pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2834         if (!pagelist)
2835                 goto fail_nopagelist;
2836         ceph_pagelist_init(pagelist);
2837
2838         reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2839         if (!reply)
2840                 goto fail_nomsg;
2841
2842         mutex_lock(&session->s_mutex);
2843         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2844         session->s_seq = 0;
2845
2846         dout("session %p state %s\n", session,
2847              ceph_session_state_name(session->s_state));
2848
2849         spin_lock(&session->s_gen_ttl_lock);
2850         session->s_cap_gen++;
2851         spin_unlock(&session->s_gen_ttl_lock);
2852
2853         spin_lock(&session->s_cap_lock);
2854         /* don't know if session is readonly */
2855         session->s_readonly = 0;
2856         /*
2857          * notify __ceph_remove_cap() that we are composing cap reconnect.
2858          * If a cap get released before being added to the cap reconnect,
2859          * __ceph_remove_cap() should skip queuing cap release.
2860          */
2861         session->s_cap_reconnect = 1;
2862         /* drop old cap expires; we're about to reestablish that state */
2863         discard_cap_releases(mdsc, session);
2864         spin_unlock(&session->s_cap_lock);
2865
2866         /* trim unused caps to reduce MDS's cache rejoin time */
2867         shrink_dcache_parent(mdsc->fsc->sb->s_root);
2868
2869         ceph_con_close(&session->s_con);
2870         ceph_con_open(&session->s_con,
2871                       CEPH_ENTITY_TYPE_MDS, mds,
2872                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2873
2874         /* replay unsafe requests */
2875         replay_unsafe_requests(mdsc, session);
2876
2877         down_read(&mdsc->snap_rwsem);
2878
2879         /* traverse this session's caps */
2880         s_nr_caps = session->s_nr_caps;
2881         err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2882         if (err)
2883                 goto fail;
2884
2885         recon_state.nr_caps = 0;
2886         recon_state.pagelist = pagelist;
2887         recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2888         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2889         if (err < 0)
2890                 goto fail;
2891
2892         spin_lock(&session->s_cap_lock);
2893         session->s_cap_reconnect = 0;
2894         spin_unlock(&session->s_cap_lock);
2895
2896         /*
2897          * snaprealms.  we provide mds with the ino, seq (version), and
2898          * parent for all of our realms.  If the mds has any newer info,
2899          * it will tell us.
2900          */
2901         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2902                 struct ceph_snap_realm *realm =
2903                         rb_entry(p, struct ceph_snap_realm, node);
2904                 struct ceph_mds_snaprealm_reconnect sr_rec;
2905
2906                 dout(" adding snap realm %llx seq %lld parent %llx\n",
2907                      realm->ino, realm->seq, realm->parent_ino);
2908                 sr_rec.ino = cpu_to_le64(realm->ino);
2909                 sr_rec.seq = cpu_to_le64(realm->seq);
2910                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
2911                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2912                 if (err)
2913                         goto fail;
2914         }
2915
2916         if (recon_state.flock)
2917                 reply->hdr.version = cpu_to_le16(2);
2918
2919         /* raced with cap release? */
2920         if (s_nr_caps != recon_state.nr_caps) {
2921                 struct page *page = list_first_entry(&pagelist->head,
2922                                                      struct page, lru);
2923                 __le32 *addr = kmap_atomic(page);
2924                 *addr = cpu_to_le32(recon_state.nr_caps);
2925                 kunmap_atomic(addr);
2926         }
2927
2928         reply->hdr.data_len = cpu_to_le32(pagelist->length);
2929         ceph_msg_data_add_pagelist(reply, pagelist);
2930         ceph_con_send(&session->s_con, reply);
2931
2932         mutex_unlock(&session->s_mutex);
2933
2934         mutex_lock(&mdsc->mutex);
2935         __wake_requests(mdsc, &session->s_waiting);
2936         mutex_unlock(&mdsc->mutex);
2937
2938         up_read(&mdsc->snap_rwsem);
2939         return;
2940
2941 fail:
2942         ceph_msg_put(reply);
2943         up_read(&mdsc->snap_rwsem);
2944         mutex_unlock(&session->s_mutex);
2945 fail_nomsg:
2946         ceph_pagelist_release(pagelist);
2947 fail_nopagelist:
2948         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
2949         return;
2950 }
2951
2952
2953 /*
2954  * compare old and new mdsmaps, kicking requests
2955  * and closing out old connections as necessary
2956  *
2957  * called under mdsc->mutex.
2958  */
2959 static void check_new_map(struct ceph_mds_client *mdsc,
2960                           struct ceph_mdsmap *newmap,
2961                           struct ceph_mdsmap *oldmap)
2962 {
2963         int i;
2964         int oldstate, newstate;
2965         struct ceph_mds_session *s;
2966
2967         dout("check_new_map new %u old %u\n",
2968              newmap->m_epoch, oldmap->m_epoch);
2969
2970         for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
2971                 if (mdsc->sessions[i] == NULL)
2972                         continue;
2973                 s = mdsc->sessions[i];
2974                 oldstate = ceph_mdsmap_get_state(oldmap, i);
2975                 newstate = ceph_mdsmap_get_state(newmap, i);
2976
2977                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
2978                      i, ceph_mds_state_name(oldstate),
2979                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
2980                      ceph_mds_state_name(newstate),
2981                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
2982                      ceph_session_state_name(s->s_state));
2983
2984                 if (i >= newmap->m_max_mds ||
2985                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
2986                            ceph_mdsmap_get_addr(newmap, i),
2987                            sizeof(struct ceph_entity_addr))) {
2988                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
2989                                 /* the session never opened, just close it
2990                                  * out now */
2991                                 __wake_requests(mdsc, &s->s_waiting);
2992                                 __unregister_session(mdsc, s);
2993                         } else {
2994                                 /* just close it */
2995                                 mutex_unlock(&mdsc->mutex);
2996                                 mutex_lock(&s->s_mutex);
2997                                 mutex_lock(&mdsc->mutex);
2998                                 ceph_con_close(&s->s_con);
2999                                 mutex_unlock(&s->s_mutex);
3000                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
3001                         }
3002                 } else if (oldstate == newstate) {
3003                         continue;  /* nothing new with this mds */
3004                 }
3005
3006                 /*
3007                  * send reconnect?
3008                  */
3009                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3010                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3011                         mutex_unlock(&mdsc->mutex);
3012                         send_mds_reconnect(mdsc, s);
3013                         mutex_lock(&mdsc->mutex);
3014                 }
3015
3016                 /*
3017                  * kick request on any mds that has gone active.
3018                  */
3019                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3020                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3021                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3022                             oldstate != CEPH_MDS_STATE_STARTING)
3023                                 pr_info("mds%d recovery completed\n", s->s_mds);
3024                         kick_requests(mdsc, i);
3025                         ceph_kick_flushing_caps(mdsc, s);
3026                         wake_up_session_caps(s, 1);
3027                 }
3028         }
3029
3030         for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3031                 s = mdsc->sessions[i];
3032                 if (!s)
3033                         continue;
3034                 if (!ceph_mdsmap_is_laggy(newmap, i))
3035                         continue;
3036                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3037                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3038                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3039                         dout(" connecting to export targets of laggy mds%d\n",
3040                              i);
3041                         __open_export_target_sessions(mdsc, s);
3042                 }
3043         }
3044 }
3045
3046
3047
3048 /*
3049  * leases
3050  */
3051
3052 /*
3053  * caller must hold session s_mutex, dentry->d_lock
3054  */
3055 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3056 {
3057         struct ceph_dentry_info *di = ceph_dentry(dentry);
3058
3059         ceph_put_mds_session(di->lease_session);
3060         di->lease_session = NULL;
3061 }
3062
3063 static void handle_lease(struct ceph_mds_client *mdsc,
3064                          struct ceph_mds_session *session,
3065                          struct ceph_msg *msg)
3066 {
3067         struct super_block *sb = mdsc->fsc->sb;
3068         struct inode *inode;
3069         struct dentry *parent, *dentry;
3070         struct ceph_dentry_info *di;
3071         int mds = session->s_mds;
3072         struct ceph_mds_lease *h = msg->front.iov_base;
3073         u32 seq;
3074         struct ceph_vino vino;
3075         struct qstr dname;
3076         int release = 0;
3077
3078         dout("handle_lease from mds%d\n", mds);
3079
3080         /* decode */
3081         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3082                 goto bad;
3083         vino.ino = le64_to_cpu(h->ino);
3084         vino.snap = CEPH_NOSNAP;
3085         seq = le32_to_cpu(h->seq);
3086         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3087         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3088         if (dname.len != get_unaligned_le32(h+1))
3089                 goto bad;
3090
3091         /* lookup inode */
3092         inode = ceph_find_inode(sb, vino);
3093         dout("handle_lease %s, ino %llx %p %.*s\n",
3094              ceph_lease_op_name(h->action), vino.ino, inode,
3095              dname.len, dname.name);
3096
3097         mutex_lock(&session->s_mutex);
3098         session->s_seq++;
3099
3100         if (inode == NULL) {
3101                 dout("handle_lease no inode %llx\n", vino.ino);
3102                 goto release;
3103         }
3104
3105         /* dentry */
3106         parent = d_find_alias(inode);
3107         if (!parent) {
3108                 dout("no parent dentry on inode %p\n", inode);
3109                 WARN_ON(1);
3110                 goto release;  /* hrm... */
3111         }
3112         dname.hash = full_name_hash(dname.name, dname.len);
3113         dentry = d_lookup(parent, &dname);
3114         dput(parent);
3115         if (!dentry)
3116                 goto release;
3117
3118         spin_lock(&dentry->d_lock);
3119         di = ceph_dentry(dentry);
3120         switch (h->action) {
3121         case CEPH_MDS_LEASE_REVOKE:
3122                 if (di->lease_session == session) {
3123                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3124                                 h->seq = cpu_to_le32(di->lease_seq);
3125                         __ceph_mdsc_drop_dentry_lease(dentry);
3126                 }
3127                 release = 1;
3128                 break;
3129
3130         case CEPH_MDS_LEASE_RENEW:
3131                 if (di->lease_session == session &&
3132                     di->lease_gen == session->s_cap_gen &&
3133                     di->lease_renew_from &&
3134                     di->lease_renew_after == 0) {
3135                         unsigned long duration =
3136                                 le32_to_cpu(h->duration_ms) * HZ / 1000;
3137
3138                         di->lease_seq = seq;
3139                         dentry->d_time = di->lease_renew_from + duration;
3140                         di->lease_renew_after = di->lease_renew_from +
3141                                 (duration >> 1);
3142                         di->lease_renew_from = 0;
3143                 }
3144                 break;
3145         }
3146         spin_unlock(&dentry->d_lock);
3147         dput(dentry);
3148
3149         if (!release)
3150                 goto out;
3151
3152 release:
3153         /* let's just reuse the same message */
3154         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3155         ceph_msg_get(msg);
3156         ceph_con_send(&session->s_con, msg);
3157
3158 out:
3159         iput(inode);
3160         mutex_unlock(&session->s_mutex);
3161         return;
3162
3163 bad:
3164         pr_err("corrupt lease message\n");
3165         ceph_msg_dump(msg);
3166 }
3167
3168 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3169                               struct inode *inode,
3170                               struct dentry *dentry, char action,
3171                               u32 seq)
3172 {
3173         struct ceph_msg *msg;
3174         struct ceph_mds_lease *lease;
3175         int len = sizeof(*lease) + sizeof(u32);
3176         int dnamelen = 0;
3177
3178         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3179              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3180         dnamelen = dentry->d_name.len;
3181         len += dnamelen;
3182
3183         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3184         if (!msg)
3185                 return;
3186         lease = msg->front.iov_base;
3187         lease->action = action;
3188         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3189         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3190         lease->seq = cpu_to_le32(seq);
3191         put_unaligned_le32(dnamelen, lease + 1);
3192         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3193
3194         /*
3195          * if this is a preemptive lease RELEASE, no need to
3196          * flush request stream, since the actual request will
3197          * soon follow.
3198          */
3199         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3200
3201         ceph_con_send(&session->s_con, msg);
3202 }
3203
3204 /*
3205  * Preemptively release a lease we expect to invalidate anyway.
3206  * Pass @inode always, @dentry is optional.
3207  */
3208 void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
3209                              struct dentry *dentry)
3210 {
3211         struct ceph_dentry_info *di;
3212         struct ceph_mds_session *session;
3213         u32 seq;
3214
3215         BUG_ON(inode == NULL);
3216         BUG_ON(dentry == NULL);
3217
3218         /* is dentry lease valid? */
3219         spin_lock(&dentry->d_lock);
3220         di = ceph_dentry(dentry);
3221         if (!di || !di->lease_session ||
3222             di->lease_session->s_mds < 0 ||
3223             di->lease_gen != di->lease_session->s_cap_gen ||
3224             !time_before(jiffies, dentry->d_time)) {
3225                 dout("lease_release inode %p dentry %p -- "
3226                      "no lease\n",
3227                      inode, dentry);
3228                 spin_unlock(&dentry->d_lock);
3229                 return;
3230         }
3231
3232         /* we do have a lease on this dentry; note mds and seq */
3233         session = ceph_get_mds_session(di->lease_session);
3234         seq = di->lease_seq;
3235         __ceph_mdsc_drop_dentry_lease(dentry);
3236         spin_unlock(&dentry->d_lock);
3237
3238         dout("lease_release inode %p dentry %p to mds%d\n",
3239              inode, dentry, session->s_mds);
3240         ceph_mdsc_lease_send_msg(session, inode, dentry,
3241                                  CEPH_MDS_LEASE_RELEASE, seq);
3242         ceph_put_mds_session(session);
3243 }
3244
3245 /*
3246  * drop all leases (and dentry refs) in preparation for umount
3247  */
3248 static void drop_leases(struct ceph_mds_client *mdsc)
3249 {
3250         int i;
3251
3252         dout("drop_leases\n");
3253         mutex_lock(&mdsc->mutex);
3254         for (i = 0; i < mdsc->max_sessions; i++) {
3255                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3256                 if (!s)
3257                         continue;
3258                 mutex_unlock(&mdsc->mutex);
3259                 mutex_lock(&s->s_mutex);
3260                 mutex_unlock(&s->s_mutex);
3261                 ceph_put_mds_session(s);
3262                 mutex_lock(&mdsc->mutex);
3263         }
3264         mutex_unlock(&mdsc->mutex);
3265 }
3266
3267
3268
3269 /*
3270  * delayed work -- periodically trim expired leases, renew caps with mds
3271  */
3272 static void schedule_delayed(struct ceph_mds_client *mdsc)
3273 {
3274         int delay = 5;
3275         unsigned hz = round_jiffies_relative(HZ * delay);
3276         schedule_delayed_work(&mdsc->delayed_work, hz);
3277 }
3278
3279 static void delayed_work(struct work_struct *work)
3280 {
3281         int i;
3282         struct ceph_mds_client *mdsc =
3283                 container_of(work, struct ceph_mds_client, delayed_work.work);
3284         int renew_interval;
3285         int renew_caps;
3286
3287         dout("mdsc delayed_work\n");
3288         ceph_check_delayed_caps(mdsc);
3289
3290         mutex_lock(&mdsc->mutex);
3291         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3292         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3293                                    mdsc->last_renew_caps);
3294         if (renew_caps)
3295                 mdsc->last_renew_caps = jiffies;
3296
3297         for (i = 0; i < mdsc->max_sessions; i++) {
3298                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3299                 if (s == NULL)
3300                         continue;
3301                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3302                         dout("resending session close request for mds%d\n",
3303                              s->s_mds);
3304                         request_close_session(mdsc, s);
3305                         ceph_put_mds_session(s);
3306                         continue;
3307                 }
3308                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3309                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3310                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3311                                 pr_info("mds%d hung\n", s->s_mds);
3312                         }
3313                 }
3314                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3315                         /* this mds is failed or recovering, just wait */
3316                         ceph_put_mds_session(s);
3317                         continue;
3318                 }
3319                 mutex_unlock(&mdsc->mutex);
3320
3321                 mutex_lock(&s->s_mutex);
3322                 if (renew_caps)
3323                         send_renew_caps(mdsc, s);
3324                 else
3325                         ceph_con_keepalive(&s->s_con);
3326                 ceph_add_cap_releases(mdsc, s);
3327                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3328                     s->s_state == CEPH_MDS_SESSION_HUNG)
3329                         ceph_send_cap_releases(mdsc, s);
3330                 mutex_unlock(&s->s_mutex);
3331                 ceph_put_mds_session(s);
3332
3333                 mutex_lock(&mdsc->mutex);
3334         }
3335         mutex_unlock(&mdsc->mutex);
3336
3337         schedule_delayed(mdsc);
3338 }
3339
3340 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3341
3342 {
3343         struct ceph_mds_client *mdsc;
3344
3345         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3346         if (!mdsc)
3347                 return -ENOMEM;
3348         mdsc->fsc = fsc;
3349         fsc->mdsc = mdsc;
3350         mutex_init(&mdsc->mutex);
3351         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3352         if (mdsc->mdsmap == NULL) {
3353                 kfree(mdsc);
3354                 return -ENOMEM;
3355         }
3356
3357         init_completion(&mdsc->safe_umount_waiters);
3358         init_waitqueue_head(&mdsc->session_close_wq);
3359         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3360         mdsc->sessions = NULL;
3361         atomic_set(&mdsc->num_sessions, 0);
3362         mdsc->max_sessions = 0;
3363         mdsc->stopping = 0;
3364         init_rwsem(&mdsc->snap_rwsem);
3365         mdsc->snap_realms = RB_ROOT;
3366         INIT_LIST_HEAD(&mdsc->snap_empty);
3367         spin_lock_init(&mdsc->snap_empty_lock);
3368         mdsc->last_tid = 0;
3369         mdsc->request_tree = RB_ROOT;
3370         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3371         mdsc->last_renew_caps = jiffies;
3372         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3373         spin_lock_init(&mdsc->cap_delay_lock);
3374         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3375         spin_lock_init(&mdsc->snap_flush_lock);
3376         mdsc->cap_flush_seq = 0;
3377         INIT_LIST_HEAD(&mdsc->cap_dirty);
3378         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3379         mdsc->num_cap_flushing = 0;
3380         spin_lock_init(&mdsc->cap_dirty_lock);
3381         init_waitqueue_head(&mdsc->cap_flushing_wq);
3382         spin_lock_init(&mdsc->dentry_lru_lock);
3383         INIT_LIST_HEAD(&mdsc->dentry_lru);
3384
3385         ceph_caps_init(mdsc);
3386         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3387
3388         return 0;
3389 }
3390
3391 /*
3392  * Wait for safe replies on open mds requests.  If we time out, drop
3393  * all requests from the tree to avoid dangling dentry refs.
3394  */
3395 static void wait_requests(struct ceph_mds_client *mdsc)
3396 {
3397         struct ceph_mds_request *req;
3398         struct ceph_fs_client *fsc = mdsc->fsc;
3399
3400         mutex_lock(&mdsc->mutex);
3401         if (__get_oldest_req(mdsc)) {
3402                 mutex_unlock(&mdsc->mutex);
3403
3404                 dout("wait_requests waiting for requests\n");
3405                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3406                                     fsc->client->options->mount_timeout * HZ);
3407
3408                 /* tear down remaining requests */
3409                 mutex_lock(&mdsc->mutex);
3410                 while ((req = __get_oldest_req(mdsc))) {
3411                         dout("wait_requests timed out on tid %llu\n",
3412                              req->r_tid);
3413                         __unregister_request(mdsc, req);
3414                 }
3415         }
3416         mutex_unlock(&mdsc->mutex);
3417         dout("wait_requests done\n");
3418 }
3419
3420 /*
3421  * called before mount is ro, and before dentries are torn down.
3422  * (hmm, does this still race with new lookups?)
3423  */
3424 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3425 {
3426         dout("pre_umount\n");
3427         mdsc->stopping = 1;
3428
3429         drop_leases(mdsc);
3430         ceph_flush_dirty_caps(mdsc);
3431         wait_requests(mdsc);
3432
3433         /*
3434          * wait for reply handlers to drop their request refs and
3435          * their inode/dcache refs
3436          */
3437         ceph_msgr_flush();
3438 }
3439
3440 /*
3441  * wait for all write mds requests to flush.
3442  */
3443 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3444 {
3445         struct ceph_mds_request *req = NULL, *nextreq;
3446         struct rb_node *n;
3447
3448         mutex_lock(&mdsc->mutex);
3449         dout("wait_unsafe_requests want %lld\n", want_tid);
3450 restart:
3451         req = __get_oldest_req(mdsc);
3452         while (req && req->r_tid <= want_tid) {
3453                 /* find next request */
3454                 n = rb_next(&req->r_node);
3455                 if (n)
3456                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3457                 else
3458                         nextreq = NULL;
3459                 if ((req->r_op & CEPH_MDS_OP_WRITE)) {
3460                         /* write op */
3461                         ceph_mdsc_get_request(req);
3462                         if (nextreq)
3463                                 ceph_mdsc_get_request(nextreq);
3464                         mutex_unlock(&mdsc->mutex);
3465                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3466                              req->r_tid, want_tid);
3467                         wait_for_completion(&req->r_safe_completion);
3468                         mutex_lock(&mdsc->mutex);
3469                         ceph_mdsc_put_request(req);
3470                         if (!nextreq)
3471                                 break;  /* next dne before, so we're done! */
3472                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3473                                 /* next request was removed from tree */
3474                                 ceph_mdsc_put_request(nextreq);
3475                                 goto restart;
3476                         }
3477                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3478                 }
3479                 req = nextreq;
3480         }
3481         mutex_unlock(&mdsc->mutex);
3482         dout("wait_unsafe_requests done\n");
3483 }
3484
3485 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3486 {
3487         u64 want_tid, want_flush;
3488
3489         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3490                 return;
3491
3492         dout("sync\n");
3493         mutex_lock(&mdsc->mutex);
3494         want_tid = mdsc->last_tid;
3495         mutex_unlock(&mdsc->mutex);
3496
3497         ceph_flush_dirty_caps(mdsc);
3498         spin_lock(&mdsc->cap_dirty_lock);
3499         want_flush = mdsc->cap_flush_seq;
3500         spin_unlock(&mdsc->cap_dirty_lock);
3501
3502         dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush);
3503
3504         wait_unsafe_requests(mdsc, want_tid);
3505         wait_caps_flush(mdsc, want_flush);
3506 }
3507
3508 /*
3509  * true if all sessions are closed, or we force unmount
3510  */
3511 static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3512 {
3513         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3514                 return true;
3515         return atomic_read(&mdsc->num_sessions) == 0;
3516 }
3517
3518 /*
3519  * called after sb is ro.
3520  */
3521 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3522 {
3523         struct ceph_mds_session *session;
3524         int i;
3525         struct ceph_fs_client *fsc = mdsc->fsc;
3526         unsigned long timeout = fsc->client->options->mount_timeout * HZ;
3527
3528         dout("close_sessions\n");
3529
3530         /* close sessions */
3531         mutex_lock(&mdsc->mutex);
3532         for (i = 0; i < mdsc->max_sessions; i++) {
3533                 session = __ceph_lookup_mds_session(mdsc, i);
3534                 if (!session)
3535                         continue;
3536                 mutex_unlock(&mdsc->mutex);
3537                 mutex_lock(&session->s_mutex);
3538                 __close_session(mdsc, session);
3539                 mutex_unlock(&session->s_mutex);
3540                 ceph_put_mds_session(session);
3541                 mutex_lock(&mdsc->mutex);
3542         }
3543         mutex_unlock(&mdsc->mutex);
3544
3545         dout("waiting for sessions to close\n");
3546         wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3547                            timeout);
3548
3549         /* tear down remaining sessions */
3550         mutex_lock(&mdsc->mutex);
3551         for (i = 0; i < mdsc->max_sessions; i++) {
3552                 if (mdsc->sessions[i]) {
3553                         session = get_session(mdsc->sessions[i]);
3554                         __unregister_session(mdsc, session);
3555                         mutex_unlock(&mdsc->mutex);
3556                         mutex_lock(&session->s_mutex);
3557                         remove_session_caps(session);
3558                         mutex_unlock(&session->s_mutex);
3559                         ceph_put_mds_session(session);
3560                         mutex_lock(&mdsc->mutex);
3561                 }
3562         }
3563         WARN_ON(!list_empty(&mdsc->cap_delay_list));
3564         mutex_unlock(&mdsc->mutex);
3565
3566         ceph_cleanup_empty_realms(mdsc);
3567
3568         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3569
3570         dout("stopped\n");
3571 }
3572
3573 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3574 {
3575         dout("stop\n");
3576         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3577         if (mdsc->mdsmap)
3578                 ceph_mdsmap_destroy(mdsc->mdsmap);
3579         kfree(mdsc->sessions);
3580         ceph_caps_finalize(mdsc);
3581 }
3582
3583 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3584 {
3585         struct ceph_mds_client *mdsc = fsc->mdsc;
3586
3587         dout("mdsc_destroy %p\n", mdsc);
3588         ceph_mdsc_stop(mdsc);
3589
3590         /* flush out any connection work with references to us */
3591         ceph_msgr_flush();
3592
3593         fsc->mdsc = NULL;
3594         kfree(mdsc);
3595         dout("mdsc_destroy %p done\n", mdsc);
3596 }
3597
3598
3599 /*
3600  * handle mds map update.
3601  */
3602 void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3603 {
3604         u32 epoch;
3605         u32 maplen;
3606         void *p = msg->front.iov_base;
3607         void *end = p + msg->front.iov_len;
3608         struct ceph_mdsmap *newmap, *oldmap;
3609         struct ceph_fsid fsid;
3610         int err = -EINVAL;
3611
3612         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3613         ceph_decode_copy(&p, &fsid, sizeof(fsid));
3614         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3615                 return;
3616         epoch = ceph_decode_32(&p);
3617         maplen = ceph_decode_32(&p);
3618         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3619
3620         /* do we need it? */
3621         ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
3622         mutex_lock(&mdsc->mutex);
3623         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3624                 dout("handle_map epoch %u <= our %u\n",
3625                      epoch, mdsc->mdsmap->m_epoch);
3626                 mutex_unlock(&mdsc->mutex);
3627                 return;
3628         }
3629
3630         newmap = ceph_mdsmap_decode(&p, end);
3631         if (IS_ERR(newmap)) {
3632                 err = PTR_ERR(newmap);
3633                 goto bad_unlock;
3634         }
3635
3636         /* swap into place */
3637         if (mdsc->mdsmap) {
3638                 oldmap = mdsc->mdsmap;
3639                 mdsc->mdsmap = newmap;
3640                 check_new_map(mdsc, newmap, oldmap);
3641                 ceph_mdsmap_destroy(oldmap);
3642         } else {
3643                 mdsc->mdsmap = newmap;  /* first mds map */
3644         }
3645         mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3646
3647         __wake_requests(mdsc, &mdsc->waiting_for_map);
3648
3649         mutex_unlock(&mdsc->mutex);
3650         schedule_delayed(mdsc);
3651         return;
3652
3653 bad_unlock:
3654         mutex_unlock(&mdsc->mutex);
3655 bad:
3656         pr_err("error decoding mdsmap %d\n", err);
3657         return;
3658 }
3659
3660 static struct ceph_connection *con_get(struct ceph_connection *con)
3661 {
3662         struct ceph_mds_session *s = con->private;
3663
3664         if (get_session(s)) {
3665                 dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3666                 return con;
3667         }
3668         dout("mdsc con_get %p FAIL\n", s);
3669         return NULL;
3670 }
3671
3672 static void con_put(struct ceph_connection *con)
3673 {
3674         struct ceph_mds_session *s = con->private;
3675
3676         dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3677         ceph_put_mds_session(s);
3678 }
3679
3680 /*
3681  * if the client is unresponsive for long enough, the mds will kill
3682  * the session entirely.
3683  */
3684 static void peer_reset(struct ceph_connection *con)
3685 {
3686         struct ceph_mds_session *s = con->private;
3687         struct ceph_mds_client *mdsc = s->s_mdsc;
3688
3689         pr_warn("mds%d closed our session\n", s->s_mds);
3690         send_mds_reconnect(mdsc, s);
3691 }
3692
3693 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3694 {
3695         struct ceph_mds_session *s = con->private;
3696         struct ceph_mds_client *mdsc = s->s_mdsc;
3697         int type = le16_to_cpu(msg->hdr.type);
3698
3699         mutex_lock(&mdsc->mutex);
3700         if (__verify_registered_session(mdsc, s) < 0) {
3701                 mutex_unlock(&mdsc->mutex);
3702                 goto out;
3703         }
3704         mutex_unlock(&mdsc->mutex);
3705
3706         switch (type) {
3707         case CEPH_MSG_MDS_MAP:
3708                 ceph_mdsc_handle_map(mdsc, msg);
3709                 break;
3710         case CEPH_MSG_CLIENT_SESSION:
3711                 handle_session(s, msg);
3712                 break;
3713         case CEPH_MSG_CLIENT_REPLY:
3714                 handle_reply(s, msg);
3715                 break;
3716         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3717                 handle_forward(mdsc, s, msg);
3718                 break;
3719         case CEPH_MSG_CLIENT_CAPS:
3720                 ceph_handle_caps(s, msg);
3721                 break;
3722         case CEPH_MSG_CLIENT_SNAP:
3723                 ceph_handle_snap(mdsc, s, msg);
3724                 break;
3725         case CEPH_MSG_CLIENT_LEASE:
3726                 handle_lease(mdsc, s, msg);
3727                 break;
3728
3729         default:
3730                 pr_err("received unknown message type %d %s\n", type,
3731                        ceph_msg_type_name(type));
3732         }
3733 out:
3734         ceph_msg_put(msg);
3735 }
3736
3737 /*
3738  * authentication
3739  */
3740
3741 /*
3742  * Note: returned pointer is the address of a structure that's
3743  * managed separately.  Caller must *not* attempt to free it.
3744  */
3745 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3746                                         int *proto, int force_new)
3747 {
3748         struct ceph_mds_session *s = con->private;
3749         struct ceph_mds_client *mdsc = s->s_mdsc;
3750         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3751         struct ceph_auth_handshake *auth = &s->s_auth;
3752
3753         if (force_new && auth->authorizer) {
3754                 ceph_auth_destroy_authorizer(ac, auth->authorizer);
3755                 auth->authorizer = NULL;
3756         }
3757         if (!auth->authorizer) {
3758                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3759                                                       auth);
3760                 if (ret)
3761                         return ERR_PTR(ret);
3762         } else {
3763                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3764                                                       auth);
3765                 if (ret)
3766                         return ERR_PTR(ret);
3767         }
3768         *proto = ac->protocol;
3769
3770         return auth;
3771 }
3772
3773
3774 static int verify_authorizer_reply(struct ceph_connection *con, int len)
3775 {
3776         struct ceph_mds_session *s = con->private;
3777         struct ceph_mds_client *mdsc = s->s_mdsc;
3778         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3779
3780         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3781 }
3782
3783 static int invalidate_authorizer(struct ceph_connection *con)
3784 {
3785         struct ceph_mds_session *s = con->private;
3786         struct ceph_mds_client *mdsc = s->s_mdsc;
3787         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3788
3789         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3790
3791         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3792 }
3793
3794 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3795                                 struct ceph_msg_header *hdr, int *skip)
3796 {
3797         struct ceph_msg *msg;
3798         int type = (int) le16_to_cpu(hdr->type);
3799         int front_len = (int) le32_to_cpu(hdr->front_len);
3800
3801         if (con->in_msg)
3802                 return con->in_msg;
3803
3804         *skip = 0;
3805         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3806         if (!msg) {
3807                 pr_err("unable to allocate msg type %d len %d\n",
3808                        type, front_len);
3809                 return NULL;
3810         }
3811
3812         return msg;
3813 }
3814
3815 static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
3816 {
3817        struct ceph_mds_session *s = con->private;
3818        struct ceph_auth_handshake *auth = &s->s_auth;
3819        return ceph_auth_sign_message(auth, msg);
3820 }
3821
3822 static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
3823 {
3824        struct ceph_mds_session *s = con->private;
3825        struct ceph_auth_handshake *auth = &s->s_auth;
3826        return ceph_auth_check_message_signature(auth, msg);
3827 }
3828
3829 static const struct ceph_connection_operations mds_con_ops = {
3830         .get = con_get,
3831         .put = con_put,
3832         .dispatch = dispatch,
3833         .get_authorizer = get_authorizer,
3834         .verify_authorizer_reply = verify_authorizer_reply,
3835         .invalidate_authorizer = invalidate_authorizer,
3836         .peer_reset = peer_reset,
3837         .alloc_msg = mds_alloc_msg,
3838         .sign_message = sign_message,
3839         .check_message_signature = check_message_signature,
3840 };
3841
3842 /* eof */