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  44  * are no longer valid.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(dentry->d_inode) != 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 = parent->d_inode;
 720
 721                 if (dir->i_sb != mdsc->fsc->sb) {
 722                         /* not this fs! */
 723                         inode = req->r_dentry->d_inode;
 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 = dn->d_inode;
 729                         dout("__choose_mds using nonsnap parent %p\n", inode);
 730                 } else {
 731                         /* dentry target */
 732                         inode = req->r_dentry->d_inode;
 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[3][2] = {
 848                 {"hostname", utsname()->nodename},
 849                 {"entity_id", opt->name ? opt->name : ""},
 850                 {NULL, NULL}
 851         };
 852
 853         /* Calculate serialized length of metadata */
 854         metadata_bytes = 4;  /* map length */
 855         for (i = 0; metadata[i][0] != NULL; ++i) {
 856                 metadata_bytes += 8 + strlen(metadata[i][0]) +
 857                         strlen(metadata[i][1]);
 858                 metadata_key_count++;
 859         }
 860
 861         /* Allocate the message */
 862         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + metadata_bytes,
 863                            GFP_NOFS, false);
 864         if (!msg) {
 865                 pr_err("create_session_msg ENOMEM creating msg\n");
 866                 return NULL;
 867         }
 868         h = msg->front.iov_base;
 869         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 870         h->seq = cpu_to_le64(seq);
 871
 872         /*
 873          * Serialize client metadata into waiting buffer space, using
 874          * the format that userspace expects for map<string, string>
 875          *
 876          * ClientSession messages with metadata are v2
 877          */
 878         msg->hdr.version = cpu_to_le16(2);
 879         msg->hdr.compat_version = cpu_to_le16(1);
 880
 881         /* The write pointer, following the session_head structure */
 882         p = msg->front.iov_base + sizeof(*h);
 883
 884         /* Number of entries in the map */
 885         ceph_encode_32(&p, metadata_key_count);
 886
 887         /* Two length-prefixed strings for each entry in the map */
 888         for (i = 0; metadata[i][0] != NULL; ++i) {
 889                 size_t const key_len = strlen(metadata[i][0]);
 890                 size_t const val_len = strlen(metadata[i][1]);
 891
 892                 ceph_encode_32(&p, key_len);
 893                 memcpy(p, metadata[i][0], key_len);
 894                 p += key_len;
 895                 ceph_encode_32(&p, val_len);
 896                 memcpy(p, metadata[i][1], val_len);
 897                 p += val_len;
 898         }
 899
 900         return msg;
 901 }
 902
 903 /*
 904  * send session open request.
 905  *
 906  * called under mdsc->mutex
 907  */
 908 static int __open_session(struct ceph_mds_client *mdsc,
 909                           struct ceph_mds_session *session)
 910 {
 911         struct ceph_msg *msg;
 912         int mstate;
 913         int mds = session->s_mds;
 914
 915         /* wait for mds to go active? */
 916         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 917         dout("open_session to mds%d (%s)\n", mds,
 918              ceph_mds_state_name(mstate));
 919         session->s_state = CEPH_MDS_SESSION_OPENING;
 920         session->s_renew_requested = jiffies;
 921
 922         /* send connect message */
 923         msg = create_session_open_msg(mdsc, session->s_seq);
 924         if (!msg)
 925                 return -ENOMEM;
 926         ceph_con_send(&session->s_con, msg);
 927         return 0;
 928 }
 929
 930 /*
 931  * open sessions for any export targets for the given mds
 932  *
 933  * called under mdsc->mutex
 934  */
 935 static struct ceph_mds_session *
 936 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
 937 {
 938         struct ceph_mds_session *session;
 939
 940         session = __ceph_lookup_mds_session(mdsc, target);
 941         if (!session) {
 942                 session = register_session(mdsc, target);
 943                 if (IS_ERR(session))
 944                         return session;
 945         }
 946         if (session->s_state == CEPH_MDS_SESSION_NEW ||
 947             session->s_state == CEPH_MDS_SESSION_CLOSING)
 948                 __open_session(mdsc, session);
 949
 950         return session;
 951 }
 952
 953 struct ceph_mds_session *
 954 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
 955 {
 956         struct ceph_mds_session *session;
 957
 958         dout("open_export_target_session to mds%d\n", target);
 959
 960         mutex_lock(&mdsc->mutex);
 961         session = __open_export_target_session(mdsc, target);
 962         mutex_unlock(&mdsc->mutex);
 963
 964         return session;
 965 }
 966
 967 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 968                                           struct ceph_mds_session *session)
 969 {
 970         struct ceph_mds_info *mi;
 971         struct ceph_mds_session *ts;
 972         int i, mds = session->s_mds;
 973
 974         if (mds >= mdsc->mdsmap->m_max_mds)
 975                 return;
 976
 977         mi = &mdsc->mdsmap->m_info[mds];
 978         dout("open_export_target_sessions for mds%d (%d targets)\n",
 979              session->s_mds, mi->num_export_targets);
 980
 981         for (i = 0; i < mi->num_export_targets; i++) {
 982                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
 983                 if (!IS_ERR(ts))
 984                         ceph_put_mds_session(ts);
 985         }
 986 }
 987
 988 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 989                                            struct ceph_mds_session *session)
 990 {
 991         mutex_lock(&mdsc->mutex);
 992         __open_export_target_sessions(mdsc, session);
 993         mutex_unlock(&mdsc->mutex);
 994 }
 995
 996 /*
 997  * session caps
 998  */
 999
1000 /*
1001  * Free preallocated cap messages assigned to this session
1002  */
1003 static void cleanup_cap_releases(struct ceph_mds_session *session)
1004 {
1005         struct ceph_msg *msg;
1006
1007         spin_lock(&session->s_cap_lock);
1008         while (!list_empty(&session->s_cap_releases)) {
1009                 msg = list_first_entry(&session->s_cap_releases,
1010                                        struct ceph_msg, list_head);
1011                 list_del_init(&msg->list_head);
1012                 ceph_msg_put(msg);
1013         }
1014         while (!list_empty(&session->s_cap_releases_done)) {
1015                 msg = list_first_entry(&session->s_cap_releases_done,
1016                                        struct ceph_msg, list_head);
1017                 list_del_init(&msg->list_head);
1018                 ceph_msg_put(msg);
1019         }
1020         spin_unlock(&session->s_cap_lock);
1021 }
1022
1023 /*
1024  * Helper to safely iterate over all caps associated with a session, with
1025  * special care taken to handle a racing __ceph_remove_cap().
1026  *
1027  * Caller must hold session s_mutex.
1028  */
1029 static int iterate_session_caps(struct ceph_mds_session *session,
1030                                  int (*cb)(struct inode *, struct ceph_cap *,
1031                                             void *), void *arg)
1032 {
1033         struct list_head *p;
1034         struct ceph_cap *cap;
1035         struct inode *inode, *last_inode = NULL;
1036         struct ceph_cap *old_cap = NULL;
1037         int ret;
1038
1039         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1040         spin_lock(&session->s_cap_lock);
1041         p = session->s_caps.next;
1042         while (p != &session->s_caps) {
1043                 cap = list_entry(p, struct ceph_cap, session_caps);
1044                 inode = igrab(&cap->ci->vfs_inode);
1045                 if (!inode) {
1046                         p = p->next;
1047                         continue;
1048                 }
1049                 session->s_cap_iterator = cap;
1050                 spin_unlock(&session->s_cap_lock);
1051
1052                 if (last_inode) {
1053                         iput(last_inode);
1054                         last_inode = NULL;
1055                 }
1056                 if (old_cap) {
1057                         ceph_put_cap(session->s_mdsc, old_cap);
1058                         old_cap = NULL;
1059                 }
1060
1061                 ret = cb(inode, cap, arg);
1062                 last_inode = inode;
1063
1064                 spin_lock(&session->s_cap_lock);
1065                 p = p->next;
1066                 if (cap->ci == NULL) {
1067                         dout("iterate_session_caps  finishing cap %p removal\n",
1068                              cap);
1069                         BUG_ON(cap->session != session);
1070                         list_del_init(&cap->session_caps);
1071                         session->s_nr_caps--;
1072                         cap->session = NULL;
1073                         old_cap = cap;  /* put_cap it w/o locks held */
1074                 }
1075                 if (ret < 0)
1076                         goto out;
1077         }
1078         ret = 0;
1079 out:
1080         session->s_cap_iterator = NULL;
1081         spin_unlock(&session->s_cap_lock);
1082
1083         iput(last_inode);
1084         if (old_cap)
1085                 ceph_put_cap(session->s_mdsc, old_cap);
1086
1087         return ret;
1088 }
1089
1090 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1091                                   void *arg)
1092 {
1093         struct ceph_inode_info *ci = ceph_inode(inode);
1094         int drop = 0;
1095
1096         dout("removing cap %p, ci is %p, inode is %p\n",
1097              cap, ci, &ci->vfs_inode);
1098         spin_lock(&ci->i_ceph_lock);
1099         __ceph_remove_cap(cap, false);
1100         if (!__ceph_is_any_real_caps(ci)) {
1101                 struct ceph_mds_client *mdsc =
1102                         ceph_sb_to_client(inode->i_sb)->mdsc;
1103
1104                 spin_lock(&mdsc->cap_dirty_lock);
1105                 if (!list_empty(&ci->i_dirty_item)) {
1106                         pr_info(" dropping dirty %s state for %p %lld\n",
1107                                 ceph_cap_string(ci->i_dirty_caps),
1108                                 inode, ceph_ino(inode));
1109                         ci->i_dirty_caps = 0;
1110                         list_del_init(&ci->i_dirty_item);
1111                         drop = 1;
1112                 }
1113                 if (!list_empty(&ci->i_flushing_item)) {
1114                         pr_info(" dropping dirty+flushing %s state for %p %lld\n",
1115                                 ceph_cap_string(ci->i_flushing_caps),
1116                                 inode, ceph_ino(inode));
1117                         ci->i_flushing_caps = 0;
1118                         list_del_init(&ci->i_flushing_item);
1119                         mdsc->num_cap_flushing--;
1120                         drop = 1;
1121                 }
1122                 if (drop && ci->i_wrbuffer_ref) {
1123                         pr_info(" dropping dirty data for %p %lld\n",
1124                                 inode, ceph_ino(inode));
1125                         ci->i_wrbuffer_ref = 0;
1126                         ci->i_wrbuffer_ref_head = 0;
1127                         drop++;
1128                 }
1129                 spin_unlock(&mdsc->cap_dirty_lock);
1130         }
1131         spin_unlock(&ci->i_ceph_lock);
1132         while (drop--)
1133                 iput(inode);
1134         return 0;
1135 }
1136
1137 /*
1138  * caller must hold session s_mutex
1139  */
1140 static void remove_session_caps(struct ceph_mds_session *session)
1141 {
1142         dout("remove_session_caps on %p\n", session);
1143         iterate_session_caps(session, remove_session_caps_cb, NULL);
1144
1145         spin_lock(&session->s_cap_lock);
1146         if (session->s_nr_caps > 0) {
1147                 struct super_block *sb = session->s_mdsc->fsc->sb;
1148                 struct inode *inode;
1149                 struct ceph_cap *cap, *prev = NULL;
1150                 struct ceph_vino vino;
1151                 /*
1152                  * iterate_session_caps() skips inodes that are being
1153                  * deleted, we need to wait until deletions are complete.
1154                  * __wait_on_freeing_inode() is designed for the job,
1155                  * but it is not exported, so use lookup inode function
1156                  * to access it.
1157                  */
1158                 while (!list_empty(&session->s_caps)) {
1159                         cap = list_entry(session->s_caps.next,
1160                                          struct ceph_cap, session_caps);
1161                         if (cap == prev)
1162                                 break;
1163                         prev = cap;
1164                         vino = cap->ci->i_vino;
1165                         spin_unlock(&session->s_cap_lock);
1166
1167                         inode = ceph_find_inode(sb, vino);
1168                         iput(inode);
1169
1170                         spin_lock(&session->s_cap_lock);
1171                 }
1172         }
1173         spin_unlock(&session->s_cap_lock);
1174
1175         BUG_ON(session->s_nr_caps > 0);
1176         BUG_ON(!list_empty(&session->s_cap_flushing));
1177         cleanup_cap_releases(session);
1178 }
1179
1180 /*
1181  * wake up any threads waiting on this session's caps.  if the cap is
1182  * old (didn't get renewed on the client reconnect), remove it now.
1183  *
1184  * caller must hold s_mutex.
1185  */
1186 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1187                               void *arg)
1188 {
1189         struct ceph_inode_info *ci = ceph_inode(inode);
1190
1191         wake_up_all(&ci->i_cap_wq);
1192         if (arg) {
1193                 spin_lock(&ci->i_ceph_lock);
1194                 ci->i_wanted_max_size = 0;
1195                 ci->i_requested_max_size = 0;
1196                 spin_unlock(&ci->i_ceph_lock);
1197         }
1198         return 0;
1199 }
1200
1201 static void wake_up_session_caps(struct ceph_mds_session *session,
1202                                  int reconnect)
1203 {
1204         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1205         iterate_session_caps(session, wake_up_session_cb,
1206                              (void *)(unsigned long)reconnect);
1207 }
1208
1209 /*
1210  * Send periodic message to MDS renewing all currently held caps.  The
1211  * ack will reset the expiration for all caps from this session.
1212  *
1213  * caller holds s_mutex
1214  */
1215 static int send_renew_caps(struct ceph_mds_client *mdsc,
1216                            struct ceph_mds_session *session)
1217 {
1218         struct ceph_msg *msg;
1219         int state;
1220
1221         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1222             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1223                 pr_info("mds%d caps stale\n", session->s_mds);
1224         session->s_renew_requested = jiffies;
1225
1226         /* do not try to renew caps until a recovering mds has reconnected
1227          * with its clients. */
1228         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1229         if (state < CEPH_MDS_STATE_RECONNECT) {
1230                 dout("send_renew_caps ignoring mds%d (%s)\n",
1231                      session->s_mds, ceph_mds_state_name(state));
1232                 return 0;
1233         }
1234
1235         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1236                 ceph_mds_state_name(state));
1237         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1238                                  ++session->s_renew_seq);
1239         if (!msg)
1240                 return -ENOMEM;
1241         ceph_con_send(&session->s_con, msg);
1242         return 0;
1243 }
1244
1245 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1246                              struct ceph_mds_session *session, u64 seq)
1247 {
1248         struct ceph_msg *msg;
1249
1250         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1251              session->s_mds, ceph_session_state_name(session->s_state), seq);
1252         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1253         if (!msg)
1254                 return -ENOMEM;
1255         ceph_con_send(&session->s_con, msg);
1256         return 0;
1257 }
1258
1259
1260 /*
1261  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1262  *
1263  * Called under session->s_mutex
1264  */
1265 static void renewed_caps(struct ceph_mds_client *mdsc,
1266                          struct ceph_mds_session *session, int is_renew)
1267 {
1268         int was_stale;
1269         int wake = 0;
1270
1271         spin_lock(&session->s_cap_lock);
1272         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1273
1274         session->s_cap_ttl = session->s_renew_requested +
1275                 mdsc->mdsmap->m_session_timeout*HZ;
1276
1277         if (was_stale) {
1278                 if (time_before(jiffies, session->s_cap_ttl)) {
1279                         pr_info("mds%d caps renewed\n", session->s_mds);
1280                         wake = 1;
1281                 } else {
1282                         pr_info("mds%d caps still stale\n", session->s_mds);
1283                 }
1284         }
1285         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1286              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1287              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1288         spin_unlock(&session->s_cap_lock);
1289
1290         if (wake)
1291                 wake_up_session_caps(session, 0);
1292 }
1293
1294 /*
1295  * send a session close request
1296  */
1297 static int request_close_session(struct ceph_mds_client *mdsc,
1298                                  struct ceph_mds_session *session)
1299 {
1300         struct ceph_msg *msg;
1301
1302         dout("request_close_session mds%d state %s seq %lld\n",
1303              session->s_mds, ceph_session_state_name(session->s_state),
1304              session->s_seq);
1305         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1306         if (!msg)
1307                 return -ENOMEM;
1308         ceph_con_send(&session->s_con, msg);
1309         return 0;
1310 }
1311
1312 /*
1313  * Called with s_mutex held.
1314  */
1315 static int __close_session(struct ceph_mds_client *mdsc,
1316                          struct ceph_mds_session *session)
1317 {
1318         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1319                 return 0;
1320         session->s_state = CEPH_MDS_SESSION_CLOSING;
1321         return request_close_session(mdsc, session);
1322 }
1323
1324 /*
1325  * Trim old(er) caps.
1326  *
1327  * Because we can't cache an inode without one or more caps, we do
1328  * this indirectly: if a cap is unused, we prune its aliases, at which
1329  * point the inode will hopefully get dropped to.
1330  *
1331  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1332  * memory pressure from the MDS, though, so it needn't be perfect.
1333  */
1334 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1335 {
1336         struct ceph_mds_session *session = arg;
1337         struct ceph_inode_info *ci = ceph_inode(inode);
1338         int used, wanted, oissued, mine;
1339
1340         if (session->s_trim_caps <= 0)
1341                 return -1;
1342
1343         spin_lock(&ci->i_ceph_lock);
1344         mine = cap->issued | cap->implemented;
1345         used = __ceph_caps_used(ci);
1346         wanted = __ceph_caps_file_wanted(ci);
1347         oissued = __ceph_caps_issued_other(ci, cap);
1348
1349         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1350              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1351              ceph_cap_string(used), ceph_cap_string(wanted));
1352         if (cap == ci->i_auth_cap) {
1353                 if (ci->i_dirty_caps | ci->i_flushing_caps)
1354                         goto out;
1355                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1356                         goto out;
1357         }
1358         if ((used | wanted) & ~oissued & mine)
1359                 goto out;   /* we need these caps */
1360
1361         session->s_trim_caps--;
1362         if (oissued) {
1363                 /* we aren't the only cap.. just remove us */
1364                 __ceph_remove_cap(cap, true);
1365         } else {
1366                 /* try to drop referring dentries */
1367                 spin_unlock(&ci->i_ceph_lock);
1368                 d_prune_aliases(inode);
1369                 dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1370                      inode, cap, atomic_read(&inode->i_count));
1371                 return 0;
1372         }
1373
1374 out:
1375         spin_unlock(&ci->i_ceph_lock);
1376         return 0;
1377 }
1378
1379 /*
1380  * Trim session cap count down to some max number.
1381  */
1382 static int trim_caps(struct ceph_mds_client *mdsc,
1383                      struct ceph_mds_session *session,
1384                      int max_caps)
1385 {
1386         int trim_caps = session->s_nr_caps - max_caps;
1387
1388         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1389              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1390         if (trim_caps > 0) {
1391                 session->s_trim_caps = trim_caps;
1392                 iterate_session_caps(session, trim_caps_cb, session);
1393                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1394                      session->s_mds, session->s_nr_caps, max_caps,
1395                         trim_caps - session->s_trim_caps);
1396                 session->s_trim_caps = 0;
1397         }
1398
1399         ceph_add_cap_releases(mdsc, session);
1400         ceph_send_cap_releases(mdsc, session);
1401         return 0;
1402 }
1403
1404 /*
1405  * Allocate cap_release messages.  If there is a partially full message
1406  * in the queue, try to allocate enough to cover it's remainder, so that
1407  * we can send it immediately.
1408  *
1409  * Called under s_mutex.
1410  */
1411 int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
1412                           struct ceph_mds_session *session)
1413 {
1414         struct ceph_msg *msg, *partial = NULL;
1415         struct ceph_mds_cap_release *head;
1416         int err = -ENOMEM;
1417         int extra = mdsc->fsc->mount_options->cap_release_safety;
1418         int num;
1419
1420         dout("add_cap_releases %p mds%d extra %d\n", session, session->s_mds,
1421              extra);
1422
1423         spin_lock(&session->s_cap_lock);
1424
1425         if (!list_empty(&session->s_cap_releases)) {
1426                 msg = list_first_entry(&session->s_cap_releases,
1427                                        struct ceph_msg,
1428                                  list_head);
1429                 head = msg->front.iov_base;
1430                 num = le32_to_cpu(head->num);
1431                 if (num) {
1432                         dout(" partial %p with (%d/%d)\n", msg, num,
1433                              (int)CEPH_CAPS_PER_RELEASE);
1434                         extra += CEPH_CAPS_PER_RELEASE - num;
1435                         partial = msg;
1436                 }
1437         }
1438         while (session->s_num_cap_releases < session->s_nr_caps + extra) {
1439                 spin_unlock(&session->s_cap_lock);
1440                 msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE, PAGE_CACHE_SIZE,
1441                                    GFP_NOFS, false);
1442                 if (!msg)
1443                         goto out_unlocked;
1444                 dout("add_cap_releases %p msg %p now %d\n", session, msg,
1445                      (int)msg->front.iov_len);
1446                 head = msg->front.iov_base;
1447                 head->num = cpu_to_le32(0);
1448                 msg->front.iov_len = sizeof(*head);
1449                 spin_lock(&session->s_cap_lock);
1450                 list_add(&msg->list_head, &session->s_cap_releases);
1451                 session->s_num_cap_releases += CEPH_CAPS_PER_RELEASE;
1452         }
1453
1454         if (partial) {
1455                 head = partial->front.iov_base;
1456                 num = le32_to_cpu(head->num);
1457                 dout(" queueing partial %p with %d/%d\n", partial, num,
1458                      (int)CEPH_CAPS_PER_RELEASE);
1459                 list_move_tail(&partial->list_head,
1460                                &session->s_cap_releases_done);
1461                 session->s_num_cap_releases -= CEPH_CAPS_PER_RELEASE - num;
1462         }
1463         err = 0;
1464         spin_unlock(&session->s_cap_lock);
1465 out_unlocked:
1466         return err;
1467 }
1468
1469 static int check_cap_flush(struct inode *inode, u64 want_flush_seq)
1470 {
1471         struct ceph_inode_info *ci = ceph_inode(inode);
1472         int ret;
1473         spin_lock(&ci->i_ceph_lock);
1474         if (ci->i_flushing_caps)
1475                 ret = ci->i_cap_flush_seq >= want_flush_seq;
1476         else
1477                 ret = 1;
1478         spin_unlock(&ci->i_ceph_lock);
1479         return ret;
1480 }
1481
1482 /*
1483  * flush all dirty inode data to disk.
1484  *
1485  * returns true if we've flushed through want_flush_seq
1486  */
1487 static void wait_caps_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq)
1488 {
1489         int mds;
1490
1491         dout("check_cap_flush want %lld\n", want_flush_seq);
1492         mutex_lock(&mdsc->mutex);
1493         for (mds = 0; mds < mdsc->max_sessions; mds++) {
1494                 struct ceph_mds_session *session = mdsc->sessions[mds];
1495                 struct inode *inode = NULL;
1496
1497                 if (!session)
1498                         continue;
1499                 get_session(session);
1500                 mutex_unlock(&mdsc->mutex);
1501
1502                 mutex_lock(&session->s_mutex);
1503                 if (!list_empty(&session->s_cap_flushing)) {
1504                         struct ceph_inode_info *ci =
1505                                 list_entry(session->s_cap_flushing.next,
1506                                            struct ceph_inode_info,
1507                                            i_flushing_item);
1508
1509                         if (!check_cap_flush(&ci->vfs_inode, want_flush_seq)) {
1510                                 dout("check_cap_flush still flushing %p "
1511                                      "seq %lld <= %lld to mds%d\n",
1512                                      &ci->vfs_inode, ci->i_cap_flush_seq,
1513                                      want_flush_seq, session->s_mds);
1514                                 inode = igrab(&ci->vfs_inode);
1515                         }
1516                 }
1517                 mutex_unlock(&session->s_mutex);
1518                 ceph_put_mds_session(session);
1519
1520                 if (inode) {
1521                         wait_event(mdsc->cap_flushing_wq,
1522                                    check_cap_flush(inode, want_flush_seq));
1523                         iput(inode);
1524                 }
1525
1526                 mutex_lock(&mdsc->mutex);
1527         }
1528
1529         mutex_unlock(&mdsc->mutex);
1530         dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq);
1531 }
1532
1533 /*
1534  * called under s_mutex
1535  */
1536 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1537                             struct ceph_mds_session *session)
1538 {
1539         struct ceph_msg *msg;
1540
1541         dout("send_cap_releases mds%d\n", session->s_mds);
1542         spin_lock(&session->s_cap_lock);
1543         while (!list_empty(&session->s_cap_releases_done)) {
1544                 msg = list_first_entry(&session->s_cap_releases_done,
1545                                  struct ceph_msg, list_head);
1546                 list_del_init(&msg->list_head);
1547                 spin_unlock(&session->s_cap_lock);
1548                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1549                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1550                 ceph_con_send(&session->s_con, msg);
1551                 spin_lock(&session->s_cap_lock);
1552         }
1553         spin_unlock(&session->s_cap_lock);
1554 }
1555
1556 static void discard_cap_releases(struct ceph_mds_client *mdsc,
1557                                  struct ceph_mds_session *session)
1558 {
1559         struct ceph_msg *msg;
1560         struct ceph_mds_cap_release *head;
1561         unsigned num;
1562
1563         dout("discard_cap_releases mds%d\n", session->s_mds);
1564
1565         if (!list_empty(&session->s_cap_releases)) {
1566                 /* zero out the in-progress message */
1567                 msg = list_first_entry(&session->s_cap_releases,
1568                                         struct ceph_msg, list_head);
1569                 head = msg->front.iov_base;
1570                 num = le32_to_cpu(head->num);
1571                 dout("discard_cap_releases mds%d %p %u\n",
1572                      session->s_mds, msg, num);
1573                 head->num = cpu_to_le32(0);
1574                 msg->front.iov_len = sizeof(*head);
1575                 session->s_num_cap_releases += num;
1576         }
1577
1578         /* requeue completed messages */
1579         while (!list_empty(&session->s_cap_releases_done)) {
1580                 msg = list_first_entry(&session->s_cap_releases_done,
1581                                  struct ceph_msg, list_head);
1582                 list_del_init(&msg->list_head);
1583
1584                 head = msg->front.iov_base;
1585                 num = le32_to_cpu(head->num);
1586                 dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg,
1587                      num);
1588                 session->s_num_cap_releases += num;
1589                 head->num = cpu_to_le32(0);
1590                 msg->front.iov_len = sizeof(*head);
1591                 list_add(&msg->list_head, &session->s_cap_releases);
1592         }
1593 }
1594
1595 /*
1596  * requests
1597  */
1598
1599 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1600                                     struct inode *dir)
1601 {
1602         struct ceph_inode_info *ci = ceph_inode(dir);
1603         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1604         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1605         size_t size = sizeof(*rinfo->dir_in) + sizeof(*rinfo->dir_dname_len) +
1606                       sizeof(*rinfo->dir_dname) + sizeof(*rinfo->dir_dlease);
1607         int order, num_entries;
1608
1609         spin_lock(&ci->i_ceph_lock);
1610         num_entries = ci->i_files + ci->i_subdirs;
1611         spin_unlock(&ci->i_ceph_lock);
1612         num_entries = max(num_entries, 1);
1613         num_entries = min(num_entries, opt->max_readdir);
1614
1615         order = get_order(size * num_entries);
1616         while (order >= 0) {
1617                 rinfo->dir_in = (void*)__get_free_pages(GFP_NOFS | __GFP_NOWARN,
1618                                                         order);
1619                 if (rinfo->dir_in)
1620                         break;
1621                 order--;
1622         }
1623         if (!rinfo->dir_in)
1624                 return -ENOMEM;
1625
1626         num_entries = (PAGE_SIZE << order) / size;
1627         num_entries = min(num_entries, opt->max_readdir);
1628
1629         rinfo->dir_buf_size = PAGE_SIZE << order;
1630         req->r_num_caps = num_entries + 1;
1631         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1632         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1633         return 0;
1634 }
1635
1636 /*
1637  * Create an mds request.
1638  */
1639 struct ceph_mds_request *
1640 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1641 {
1642         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1643
1644         if (!req)
1645                 return ERR_PTR(-ENOMEM);
1646
1647         mutex_init(&req->r_fill_mutex);
1648         req->r_mdsc = mdsc;
1649         req->r_started = jiffies;
1650         req->r_resend_mds = -1;
1651         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1652         req->r_fmode = -1;
1653         kref_init(&req->r_kref);
1654         INIT_LIST_HEAD(&req->r_wait);
1655         init_completion(&req->r_completion);
1656         init_completion(&req->r_safe_completion);
1657         INIT_LIST_HEAD(&req->r_unsafe_item);
1658
1659         req->r_stamp = CURRENT_TIME;
1660
1661         req->r_op = op;
1662         req->r_direct_mode = mode;
1663         return req;
1664 }
1665
1666 /*
1667  * return oldest (lowest) request, tid in request tree, 0 if none.
1668  *
1669  * called under mdsc->mutex.
1670  */
1671 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1672 {
1673         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1674                 return NULL;
1675         return rb_entry(rb_first(&mdsc->request_tree),
1676                         struct ceph_mds_request, r_node);
1677 }
1678
1679 static u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1680 {
1681         struct ceph_mds_request *req = __get_oldest_req(mdsc);
1682
1683         if (req)
1684                 return req->r_tid;
1685         return 0;
1686 }
1687
1688 /*
1689  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1690  * on build_path_from_dentry in fs/cifs/dir.c.
1691  *
1692  * If @stop_on_nosnap, generate path relative to the first non-snapped
1693  * inode.
1694  *
1695  * Encode hidden .snap dirs as a double /, i.e.
1696  *   foo/.snap/bar -> foo//bar
1697  */
1698 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1699                            int stop_on_nosnap)
1700 {
1701         struct dentry *temp;
1702         char *path;
1703         int len, pos;
1704         unsigned seq;
1705
1706         if (dentry == NULL)
1707                 return ERR_PTR(-EINVAL);
1708
1709 retry:
1710         len = 0;
1711         seq = read_seqbegin(&rename_lock);
1712         rcu_read_lock();
1713         for (temp = dentry; !IS_ROOT(temp);) {
1714                 struct inode *inode = temp->d_inode;
1715                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1716                         len++;  /* slash only */
1717                 else if (stop_on_nosnap && inode &&
1718                          ceph_snap(inode) == CEPH_NOSNAP)
1719                         break;
1720                 else
1721                         len += 1 + temp->d_name.len;
1722                 temp = temp->d_parent;
1723         }
1724         rcu_read_unlock();
1725         if (len)
1726                 len--;  /* no leading '/' */
1727
1728         path = kmalloc(len+1, GFP_NOFS);
1729         if (path == NULL)
1730                 return ERR_PTR(-ENOMEM);
1731         pos = len;
1732         path[pos] = 0;  /* trailing null */
1733         rcu_read_lock();
1734         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1735                 struct inode *inode;
1736
1737                 spin_lock(&temp->d_lock);
1738                 inode = temp->d_inode;
1739                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1740                         dout("build_path path+%d: %p SNAPDIR\n",
1741                              pos, temp);
1742                 } else if (stop_on_nosnap && inode &&
1743                            ceph_snap(inode) == CEPH_NOSNAP) {
1744                         spin_unlock(&temp->d_lock);
1745                         break;
1746                 } else {
1747                         pos -= temp->d_name.len;
1748                         if (pos < 0) {
1749                                 spin_unlock(&temp->d_lock);
1750                                 break;
1751                         }
1752                         strncpy(path + pos, temp->d_name.name,
1753                                 temp->d_name.len);
1754                 }
1755                 spin_unlock(&temp->d_lock);
1756                 if (pos)
1757                         path[--pos] = '/';
1758                 temp = temp->d_parent;
1759         }
1760         rcu_read_unlock();
1761         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1762                 pr_err("build_path did not end path lookup where "
1763                        "expected, namelen is %d, pos is %d\n", len, pos);
1764                 /* presumably this is only possible if racing with a
1765                    rename of one of the parent directories (we can not
1766                    lock the dentries above us to prevent this, but
1767                    retrying should be harmless) */
1768                 kfree(path);
1769                 goto retry;
1770         }
1771
1772         *base = ceph_ino(temp->d_inode);
1773         *plen = len;
1774         dout("build_path on %p %d built %llx '%.*s'\n",
1775              dentry, d_count(dentry), *base, len, path);
1776         return path;
1777 }
1778
1779 static int build_dentry_path(struct dentry *dentry,
1780                              const char **ppath, int *ppathlen, u64 *pino,
1781                              int *pfreepath)
1782 {
1783         char *path;
1784
1785         if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP) {
1786                 *pino = ceph_ino(dentry->d_parent->d_inode);
1787                 *ppath = dentry->d_name.name;
1788                 *ppathlen = dentry->d_name.len;
1789                 return 0;
1790         }
1791         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1792         if (IS_ERR(path))
1793                 return PTR_ERR(path);
1794         *ppath = path;
1795         *pfreepath = 1;
1796         return 0;
1797 }
1798
1799 static int build_inode_path(struct inode *inode,
1800                             const char **ppath, int *ppathlen, u64 *pino,
1801                             int *pfreepath)
1802 {
1803         struct dentry *dentry;
1804         char *path;
1805
1806         if (ceph_snap(inode) == CEPH_NOSNAP) {
1807                 *pino = ceph_ino(inode);
1808                 *ppathlen = 0;
1809                 return 0;
1810         }
1811         dentry = d_find_alias(inode);
1812         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1813         dput(dentry);
1814         if (IS_ERR(path))
1815                 return PTR_ERR(path);
1816         *ppath = path;
1817         *pfreepath = 1;
1818         return 0;
1819 }
1820
1821 /*
1822  * request arguments may be specified via an inode *, a dentry *, or
1823  * an explicit ino+path.
1824  */
1825 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1826                                   const char *rpath, u64 rino,
1827                                   const char **ppath, int *pathlen,
1828                                   u64 *ino, int *freepath)
1829 {
1830         int r = 0;
1831
1832         if (rinode) {
1833                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1834                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1835                      ceph_snap(rinode));
1836         } else if (rdentry) {
1837                 r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1838                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1839                      *ppath);
1840         } else if (rpath || rino) {
1841                 *ino = rino;
1842                 *ppath = rpath;
1843                 *pathlen = rpath ? strlen(rpath) : 0;
1844                 dout(" path %.*s\n", *pathlen, rpath);
1845         }
1846
1847         return r;
1848 }
1849
1850 /*
1851  * called under mdsc->mutex
1852  */
1853 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1854                                                struct ceph_mds_request *req,
1855                                                int mds)
1856 {
1857         struct ceph_msg *msg;
1858         struct ceph_mds_request_head *head;
1859         const char *path1 = NULL;
1860         const char *path2 = NULL;
1861         u64 ino1 = 0, ino2 = 0;
1862         int pathlen1 = 0, pathlen2 = 0;
1863         int freepath1 = 0, freepath2 = 0;
1864         int len;
1865         u16 releases;
1866         void *p, *end;
1867         int ret;
1868
1869         ret = set_request_path_attr(req->r_inode, req->r_dentry,
1870                               req->r_path1, req->r_ino1.ino,
1871                               &path1, &pathlen1, &ino1, &freepath1);
1872         if (ret < 0) {
1873                 msg = ERR_PTR(ret);
1874                 goto out;
1875         }
1876
1877         ret = set_request_path_attr(NULL, req->r_old_dentry,
1878                               req->r_path2, req->r_ino2.ino,
1879                               &path2, &pathlen2, &ino2, &freepath2);
1880         if (ret < 0) {
1881                 msg = ERR_PTR(ret);
1882                 goto out_free1;
1883         }
1884
1885         len = sizeof(*head) +
1886                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1887                 sizeof(struct timespec);
1888
1889         /* calculate (max) length for cap releases */
1890         len += sizeof(struct ceph_mds_request_release) *
1891                 (!!req->r_inode_drop + !!req->r_dentry_drop +
1892                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1893         if (req->r_dentry_drop)
1894                 len += req->r_dentry->d_name.len;
1895         if (req->r_old_dentry_drop)
1896                 len += req->r_old_dentry->d_name.len;
1897
1898         msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1899         if (!msg) {
1900                 msg = ERR_PTR(-ENOMEM);
1901                 goto out_free2;
1902         }
1903
1904         msg->hdr.version = cpu_to_le16(2);
1905         msg->hdr.tid = cpu_to_le64(req->r_tid);
1906
1907         head = msg->front.iov_base;
1908         p = msg->front.iov_base + sizeof(*head);
1909         end = msg->front.iov_base + msg->front.iov_len;
1910
1911         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1912         head->op = cpu_to_le32(req->r_op);
1913         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1914         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1915         head->args = req->r_args;
1916
1917         ceph_encode_filepath(&p, end, ino1, path1);
1918         ceph_encode_filepath(&p, end, ino2, path2);
1919
1920         /* make note of release offset, in case we need to replay */
1921         req->r_request_release_offset = p - msg->front.iov_base;
1922
1923         /* cap releases */
1924         releases = 0;
1925         if (req->r_inode_drop)
1926                 releases += ceph_encode_inode_release(&p,
1927                       req->r_inode ? req->r_inode : req->r_dentry->d_inode,
1928                       mds, req->r_inode_drop, req->r_inode_unless, 0);
1929         if (req->r_dentry_drop)
1930                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
1931                        mds, req->r_dentry_drop, req->r_dentry_unless);
1932         if (req->r_old_dentry_drop)
1933                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1934                        mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1935         if (req->r_old_inode_drop)
1936                 releases += ceph_encode_inode_release(&p,
1937                       req->r_old_dentry->d_inode,
1938                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1939         head->num_releases = cpu_to_le16(releases);
1940
1941         /* time stamp */
1942         ceph_encode_copy(&p, &req->r_stamp, sizeof(req->r_stamp));
1943
1944         BUG_ON(p > end);
1945         msg->front.iov_len = p - msg->front.iov_base;
1946         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1947
1948         if (req->r_pagelist) {
1949                 struct ceph_pagelist *pagelist = req->r_pagelist;
1950                 atomic_inc(&pagelist->refcnt);
1951                 ceph_msg_data_add_pagelist(msg, pagelist);
1952                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
1953         } else {
1954                 msg->hdr.data_len = 0;
1955         }
1956
1957         msg->hdr.data_off = cpu_to_le16(0);
1958
1959 out_free2:
1960         if (freepath2)
1961                 kfree((char *)path2);
1962 out_free1:
1963         if (freepath1)
1964                 kfree((char *)path1);
1965 out:
1966         return msg;
1967 }
1968
1969 /*
1970  * called under mdsc->mutex if error, under no mutex if
1971  * success.
1972  */
1973 static void complete_request(struct ceph_mds_client *mdsc,
1974                              struct ceph_mds_request *req)
1975 {
1976         if (req->r_callback)
1977                 req->r_callback(mdsc, req);
1978         else
1979                 complete_all(&req->r_completion);
1980 }
1981
1982 /*
1983  * called under mdsc->mutex
1984  */
1985 static int __prepare_send_request(struct ceph_mds_client *mdsc,
1986                                   struct ceph_mds_request *req,
1987                                   int mds)
1988 {
1989         struct ceph_mds_request_head *rhead;
1990         struct ceph_msg *msg;
1991         int flags = 0;
1992
1993         req->r_attempts++;
1994         if (req->r_inode) {
1995                 struct ceph_cap *cap =
1996                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
1997
1998                 if (cap)
1999                         req->r_sent_on_mseq = cap->mseq;
2000                 else
2001                         req->r_sent_on_mseq = -1;
2002         }
2003         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2004              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2005
2006         if (req->r_got_unsafe) {
2007                 void *p;
2008                 /*
2009                  * Replay.  Do not regenerate message (and rebuild
2010                  * paths, etc.); just use the original message.
2011                  * Rebuilding paths will break for renames because
2012                  * d_move mangles the src name.
2013                  */
2014                 msg = req->r_request;
2015                 rhead = msg->front.iov_base;
2016
2017                 flags = le32_to_cpu(rhead->flags);
2018                 flags |= CEPH_MDS_FLAG_REPLAY;
2019                 rhead->flags = cpu_to_le32(flags);
2020
2021                 if (req->r_target_inode)
2022                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2023
2024                 rhead->num_retry = req->r_attempts - 1;
2025
2026                 /* remove cap/dentry releases from message */
2027                 rhead->num_releases = 0;
2028
2029                 /* time stamp */
2030                 p = msg->front.iov_base + req->r_request_release_offset;
2031                 ceph_encode_copy(&p, &req->r_stamp, sizeof(req->r_stamp));
2032
2033                 msg->front.iov_len = p - msg->front.iov_base;
2034                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2035                 return 0;
2036         }
2037
2038         if (req->r_request) {
2039                 ceph_msg_put(req->r_request);
2040                 req->r_request = NULL;
2041         }
2042         msg = create_request_message(mdsc, req, mds);
2043         if (IS_ERR(msg)) {
2044                 req->r_err = PTR_ERR(msg);
2045                 complete_request(mdsc, req);
2046                 return PTR_ERR(msg);
2047         }
2048         req->r_request = msg;
2049
2050         rhead = msg->front.iov_base;
2051         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2052         if (req->r_got_unsafe)
2053                 flags |= CEPH_MDS_FLAG_REPLAY;
2054         if (req->r_locked_dir)
2055                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2056         rhead->flags = cpu_to_le32(flags);
2057         rhead->num_fwd = req->r_num_fwd;
2058         rhead->num_retry = req->r_attempts - 1;
2059         rhead->ino = 0;
2060
2061         dout(" r_locked_dir = %p\n", req->r_locked_dir);
2062         return 0;
2063 }
2064
2065 /*
2066  * send request, or put it on the appropriate wait list.
2067  */
2068 static int __do_request(struct ceph_mds_client *mdsc,
2069                         struct ceph_mds_request *req)
2070 {
2071         struct ceph_mds_session *session = NULL;
2072         int mds = -1;
2073         int err = -EAGAIN;
2074
2075         if (req->r_err || req->r_got_result) {
2076                 if (req->r_aborted)
2077                         __unregister_request(mdsc, req);
2078                 goto out;
2079         }
2080
2081         if (req->r_timeout &&
2082             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2083                 dout("do_request timed out\n");
2084                 err = -EIO;
2085                 goto finish;
2086         }
2087
2088         put_request_session(req);
2089
2090         mds = __choose_mds(mdsc, req);
2091         if (mds < 0 ||
2092             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2093                 dout("do_request no mds or not active, waiting for map\n");
2094                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2095                 goto out;
2096         }
2097
2098         /* get, open session */
2099         session = __ceph_lookup_mds_session(mdsc, mds);
2100         if (!session) {
2101                 session = register_session(mdsc, mds);
2102                 if (IS_ERR(session)) {
2103                         err = PTR_ERR(session);
2104                         goto finish;
2105                 }
2106         }
2107         req->r_session = get_session(session);
2108
2109         dout("do_request mds%d session %p state %s\n", mds, session,
2110              ceph_session_state_name(session->s_state));
2111         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2112             session->s_state != CEPH_MDS_SESSION_HUNG) {
2113                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2114                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2115                         __open_session(mdsc, session);
2116                 list_add(&req->r_wait, &session->s_waiting);
2117                 goto out_session;
2118         }
2119
2120         /* send request */
2121         req->r_resend_mds = -1;   /* forget any previous mds hint */
2122
2123         if (req->r_request_started == 0)   /* note request start time */
2124                 req->r_request_started = jiffies;
2125
2126         err = __prepare_send_request(mdsc, req, mds);
2127         if (!err) {
2128                 ceph_msg_get(req->r_request);
2129                 ceph_con_send(&session->s_con, req->r_request);
2130         }
2131
2132 out_session:
2133         ceph_put_mds_session(session);
2134 out:
2135         return err;
2136
2137 finish:
2138         req->r_err = err;
2139         complete_request(mdsc, req);
2140         goto out;
2141 }
2142
2143 /*
2144  * called under mdsc->mutex
2145  */
2146 static void __wake_requests(struct ceph_mds_client *mdsc,
2147                             struct list_head *head)
2148 {
2149         struct ceph_mds_request *req;
2150         LIST_HEAD(tmp_list);
2151
2152         list_splice_init(head, &tmp_list);
2153
2154         while (!list_empty(&tmp_list)) {
2155                 req = list_entry(tmp_list.next,
2156                                  struct ceph_mds_request, r_wait);
2157                 list_del_init(&req->r_wait);
2158                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2159                 __do_request(mdsc, req);
2160         }
2161 }
2162
2163 /*
2164  * Wake up threads with requests pending for @mds, so that they can
2165  * resubmit their requests to a possibly different mds.
2166  */
2167 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2168 {
2169         struct ceph_mds_request *req;
2170         struct rb_node *p = rb_first(&mdsc->request_tree);
2171
2172         dout("kick_requests mds%d\n", mds);
2173         while (p) {
2174                 req = rb_entry(p, struct ceph_mds_request, r_node);
2175                 p = rb_next(p);
2176                 if (req->r_got_unsafe)
2177                         continue;
2178                 if (req->r_session &&
2179                     req->r_session->s_mds == mds) {
2180                         dout(" kicking tid %llu\n", req->r_tid);
2181                         list_del_init(&req->r_wait);
2182                         __do_request(mdsc, req);
2183                 }
2184         }
2185 }
2186
2187 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2188                               struct ceph_mds_request *req)
2189 {
2190         dout("submit_request on %p\n", req);
2191         mutex_lock(&mdsc->mutex);
2192         __register_request(mdsc, req, NULL);
2193         __do_request(mdsc, req);
2194         mutex_unlock(&mdsc->mutex);
2195 }
2196
2197 /*
2198  * Synchrously perform an mds request.  Take care of all of the
2199  * session setup, forwarding, retry details.
2200  */
2201 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2202                          struct inode *dir,
2203                          struct ceph_mds_request *req)
2204 {
2205         int err;
2206
2207         dout("do_request on %p\n", req);
2208
2209         /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2210         if (req->r_inode)
2211                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2212         if (req->r_locked_dir)
2213                 ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2214         if (req->r_old_dentry_dir)
2215                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2216                                   CEPH_CAP_PIN);
2217
2218         /* issue */
2219         mutex_lock(&mdsc->mutex);
2220         __register_request(mdsc, req, dir);
2221         __do_request(mdsc, req);
2222
2223         if (req->r_err) {
2224                 err = req->r_err;
2225                 __unregister_request(mdsc, req);
2226                 dout("do_request early error %d\n", err);
2227                 goto out;
2228         }
2229
2230         /* wait */
2231         mutex_unlock(&mdsc->mutex);
2232         dout("do_request waiting\n");
2233         if (req->r_timeout) {
2234                 err = (long)wait_for_completion_killable_timeout(
2235                         &req->r_completion, req->r_timeout);
2236                 if (err == 0)
2237                         err = -EIO;
2238         } else if (req->r_wait_for_completion) {
2239                 err = req->r_wait_for_completion(mdsc, req);
2240         } else {
2241                 err = wait_for_completion_killable(&req->r_completion);
2242         }
2243         dout("do_request waited, got %d\n", err);
2244         mutex_lock(&mdsc->mutex);
2245
2246         /* only abort if we didn't race with a real reply */
2247         if (req->r_got_result) {
2248                 err = le32_to_cpu(req->r_reply_info.head->result);
2249         } else if (err < 0) {
2250                 dout("aborted request %lld with %d\n", req->r_tid, err);
2251
2252                 /*
2253                  * ensure we aren't running concurrently with
2254                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2255                  * rely on locks (dir mutex) held by our caller.
2256                  */
2257                 mutex_lock(&req->r_fill_mutex);
2258                 req->r_err = err;
2259                 req->r_aborted = true;
2260                 mutex_unlock(&req->r_fill_mutex);
2261
2262                 if (req->r_locked_dir &&
2263                     (req->r_op & CEPH_MDS_OP_WRITE))
2264                         ceph_invalidate_dir_request(req);
2265         } else {
2266                 err = req->r_err;
2267         }
2268
2269 out:
2270         mutex_unlock(&mdsc->mutex);
2271         dout("do_request %p done, result %d\n", req, err);
2272         return err;
2273 }
2274
2275 /*
2276  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2277  * namespace request.
2278  */
2279 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2280 {
2281         struct inode *inode = req->r_locked_dir;
2282
2283         dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2284
2285         ceph_dir_clear_complete(inode);
2286         if (req->r_dentry)
2287                 ceph_invalidate_dentry_lease(req->r_dentry);
2288         if (req->r_old_dentry)
2289                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2290 }
2291
2292 /*
2293  * Handle mds reply.
2294  *
2295  * We take the session mutex and parse and process the reply immediately.
2296  * This preserves the logical ordering of replies, capabilities, etc., sent
2297  * by the MDS as they are applied to our local cache.
2298  */
2299 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2300 {
2301         struct ceph_mds_client *mdsc = session->s_mdsc;
2302         struct ceph_mds_request *req;
2303         struct ceph_mds_reply_head *head = msg->front.iov_base;
2304         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2305         struct ceph_snap_realm *realm;
2306         u64 tid;
2307         int err, result;
2308         int mds = session->s_mds;
2309
2310         if (msg->front.iov_len < sizeof(*head)) {
2311                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2312                 ceph_msg_dump(msg);
2313                 return;
2314         }
2315
2316         /* get request, session */
2317         tid = le64_to_cpu(msg->hdr.tid);
2318         mutex_lock(&mdsc->mutex);
2319         req = __lookup_request(mdsc, tid);
2320         if (!req) {
2321                 dout("handle_reply on unknown tid %llu\n", tid);
2322                 mutex_unlock(&mdsc->mutex);
2323                 return;
2324         }
2325         dout("handle_reply %p\n", req);
2326
2327         /* correct session? */
2328         if (req->r_session != session) {
2329                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2330                        " not mds%d\n", tid, session->s_mds,
2331                        req->r_session ? req->r_session->s_mds : -1);
2332                 mutex_unlock(&mdsc->mutex);
2333                 goto out;
2334         }
2335
2336         /* dup? */
2337         if ((req->r_got_unsafe && !head->safe) ||
2338             (req->r_got_safe && head->safe)) {
2339                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2340                            head->safe ? "safe" : "unsafe", tid, mds);
2341                 mutex_unlock(&mdsc->mutex);
2342                 goto out;
2343         }
2344         if (req->r_got_safe && !head->safe) {
2345                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2346                            tid, mds);
2347                 mutex_unlock(&mdsc->mutex);
2348                 goto out;
2349         }
2350
2351         result = le32_to_cpu(head->result);
2352
2353         /*
2354          * Handle an ESTALE
2355          * if we're not talking to the authority, send to them
2356          * if the authority has changed while we weren't looking,
2357          * send to new authority
2358          * Otherwise we just have to return an ESTALE
2359          */
2360         if (result == -ESTALE) {
2361                 dout("got ESTALE on request %llu", req->r_tid);
2362                 req->r_resend_mds = -1;
2363                 if (req->r_direct_mode != USE_AUTH_MDS) {
2364                         dout("not using auth, setting for that now");
2365                         req->r_direct_mode = USE_AUTH_MDS;
2366                         __do_request(mdsc, req);
2367                         mutex_unlock(&mdsc->mutex);
2368                         goto out;
2369                 } else  {
2370                         int mds = __choose_mds(mdsc, req);
2371                         if (mds >= 0 && mds != req->r_session->s_mds) {
2372                                 dout("but auth changed, so resending");
2373                                 __do_request(mdsc, req);
2374                                 mutex_unlock(&mdsc->mutex);
2375                                 goto out;
2376                         }
2377                 }
2378                 dout("have to return ESTALE on request %llu", req->r_tid);
2379         }
2380
2381
2382         if (head->safe) {
2383                 req->r_got_safe = true;
2384                 __unregister_request(mdsc, req);
2385
2386                 if (req->r_got_unsafe) {
2387                         /*
2388                          * We already handled the unsafe response, now do the
2389                          * cleanup.  No need to examine the response; the MDS
2390                          * doesn't include any result info in the safe
2391                          * response.  And even if it did, there is nothing
2392                          * useful we could do with a revised return value.
2393                          */
2394                         dout("got safe reply %llu, mds%d\n", tid, mds);
2395                         list_del_init(&req->r_unsafe_item);
2396
2397                         /* last unsafe request during umount? */
2398                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2399                                 complete_all(&mdsc->safe_umount_waiters);
2400                         mutex_unlock(&mdsc->mutex);
2401                         goto out;
2402                 }
2403         } else {
2404                 req->r_got_unsafe = true;
2405                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2406         }
2407
2408         dout("handle_reply tid %lld result %d\n", tid, result);
2409         rinfo = &req->r_reply_info;
2410         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2411         mutex_unlock(&mdsc->mutex);
2412
2413         mutex_lock(&session->s_mutex);
2414         if (err < 0) {
2415                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2416                 ceph_msg_dump(msg);
2417                 goto out_err;
2418         }
2419
2420         /* snap trace */
2421         realm = NULL;
2422         if (rinfo->snapblob_len) {
2423                 down_write(&mdsc->snap_rwsem);
2424                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2425                                 rinfo->snapblob + rinfo->snapblob_len,
2426                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2427                                 &realm);
2428                 downgrade_write(&mdsc->snap_rwsem);
2429         } else {
2430                 down_read(&mdsc->snap_rwsem);
2431         }
2432
2433         /* insert trace into our cache */
2434         mutex_lock(&req->r_fill_mutex);
2435         err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2436         if (err == 0) {
2437                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2438                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2439                         ceph_readdir_prepopulate(req, req->r_session);
2440                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2441         }
2442         mutex_unlock(&req->r_fill_mutex);
2443
2444         up_read(&mdsc->snap_rwsem);
2445         if (realm)
2446                 ceph_put_snap_realm(mdsc, realm);
2447 out_err:
2448         mutex_lock(&mdsc->mutex);
2449         if (!req->r_aborted) {
2450                 if (err) {
2451                         req->r_err = err;
2452                 } else {
2453                         req->r_reply = msg;
2454                         ceph_msg_get(msg);
2455                         req->r_got_result = true;
2456                 }
2457         } else {
2458                 dout("reply arrived after request %lld was aborted\n", tid);
2459         }
2460         mutex_unlock(&mdsc->mutex);
2461
2462         ceph_add_cap_releases(mdsc, req->r_session);
2463         mutex_unlock(&session->s_mutex);
2464
2465         /* kick calling process */
2466         complete_request(mdsc, req);
2467 out:
2468         ceph_mdsc_put_request(req);
2469         return;
2470 }
2471
2472
2473
2474 /*
2475  * handle mds notification that our request has been forwarded.
2476  */
2477 static void handle_forward(struct ceph_mds_client *mdsc,
2478                            struct ceph_mds_session *session,
2479                            struct ceph_msg *msg)
2480 {
2481         struct ceph_mds_request *req;
2482         u64 tid = le64_to_cpu(msg->hdr.tid);
2483         u32 next_mds;
2484         u32 fwd_seq;
2485         int err = -EINVAL;
2486         void *p = msg->front.iov_base;
2487         void *end = p + msg->front.iov_len;
2488
2489         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2490         next_mds = ceph_decode_32(&p);
2491         fwd_seq = ceph_decode_32(&p);
2492
2493         mutex_lock(&mdsc->mutex);
2494         req = __lookup_request(mdsc, tid);
2495         if (!req) {
2496                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2497                 goto out;  /* dup reply? */
2498         }
2499
2500         if (req->r_aborted) {
2501                 dout("forward tid %llu aborted, unregistering\n", tid);
2502                 __unregister_request(mdsc, req);
2503         } else if (fwd_seq <= req->r_num_fwd) {
2504                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2505                      tid, next_mds, req->r_num_fwd, fwd_seq);
2506         } else {
2507                 /* resend. forward race not possible; mds would drop */
2508                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2509                 BUG_ON(req->r_err);
2510                 BUG_ON(req->r_got_result);
2511                 req->r_num_fwd = fwd_seq;
2512                 req->r_resend_mds = next_mds;
2513                 put_request_session(req);
2514                 __do_request(mdsc, req);
2515         }
2516         ceph_mdsc_put_request(req);
2517 out:
2518         mutex_unlock(&mdsc->mutex);
2519         return;
2520
2521 bad:
2522         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2523 }
2524
2525 /*
2526  * handle a mds session control message
2527  */
2528 static void handle_session(struct ceph_mds_session *session,
2529                            struct ceph_msg *msg)
2530 {
2531         struct ceph_mds_client *mdsc = session->s_mdsc;
2532         u32 op;
2533         u64 seq;
2534         int mds = session->s_mds;
2535         struct ceph_mds_session_head *h = msg->front.iov_base;
2536         int wake = 0;
2537
2538         /* decode */
2539         if (msg->front.iov_len != sizeof(*h))
2540                 goto bad;
2541         op = le32_to_cpu(h->op);
2542         seq = le64_to_cpu(h->seq);
2543
2544         mutex_lock(&mdsc->mutex);
2545         if (op == CEPH_SESSION_CLOSE)
2546                 __unregister_session(mdsc, session);
2547         /* FIXME: this ttl calculation is generous */
2548         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2549         mutex_unlock(&mdsc->mutex);
2550
2551         mutex_lock(&session->s_mutex);
2552
2553         dout("handle_session mds%d %s %p state %s seq %llu\n",
2554              mds, ceph_session_op_name(op), session,
2555              ceph_session_state_name(session->s_state), seq);
2556
2557         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2558                 session->s_state = CEPH_MDS_SESSION_OPEN;
2559                 pr_info("mds%d came back\n", session->s_mds);
2560         }
2561
2562         switch (op) {
2563         case CEPH_SESSION_OPEN:
2564                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2565                         pr_info("mds%d reconnect success\n", session->s_mds);
2566                 session->s_state = CEPH_MDS_SESSION_OPEN;
2567                 renewed_caps(mdsc, session, 0);
2568                 wake = 1;
2569                 if (mdsc->stopping)
2570                         __close_session(mdsc, session);
2571                 break;
2572
2573         case CEPH_SESSION_RENEWCAPS:
2574                 if (session->s_renew_seq == seq)
2575                         renewed_caps(mdsc, session, 1);
2576                 break;
2577
2578         case CEPH_SESSION_CLOSE:
2579                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2580                         pr_info("mds%d reconnect denied\n", session->s_mds);
2581                 remove_session_caps(session);
2582                 wake = 2; /* for good measure */
2583                 wake_up_all(&mdsc->session_close_wq);
2584                 break;
2585
2586         case CEPH_SESSION_STALE:
2587                 pr_info("mds%d caps went stale, renewing\n",
2588                         session->s_mds);
2589                 spin_lock(&session->s_gen_ttl_lock);
2590                 session->s_cap_gen++;
2591                 session->s_cap_ttl = jiffies - 1;
2592                 spin_unlock(&session->s_gen_ttl_lock);
2593                 send_renew_caps(mdsc, session);
2594                 break;
2595
2596         case CEPH_SESSION_RECALL_STATE:
2597                 trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2598                 break;
2599
2600         case CEPH_SESSION_FLUSHMSG:
2601                 send_flushmsg_ack(mdsc, session, seq);
2602                 break;
2603
2604         case CEPH_SESSION_FORCE_RO:
2605                 dout("force_session_readonly %p\n", session);
2606                 spin_lock(&session->s_cap_lock);
2607                 session->s_readonly = true;
2608                 spin_unlock(&session->s_cap_lock);
2609                 wake_up_session_caps(session, 0);
2610                 break;
2611
2612         default:
2613                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2614                 WARN_ON(1);
2615         }
2616
2617         mutex_unlock(&session->s_mutex);
2618         if (wake) {
2619                 mutex_lock(&mdsc->mutex);
2620                 __wake_requests(mdsc, &session->s_waiting);
2621                 if (wake == 2)
2622                         kick_requests(mdsc, mds);
2623                 mutex_unlock(&mdsc->mutex);
2624         }
2625         return;
2626
2627 bad:
2628         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2629                (int)msg->front.iov_len);
2630         ceph_msg_dump(msg);
2631         return;
2632 }
2633
2634
2635 /*
2636  * called under session->mutex.
2637  */
2638 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2639                                    struct ceph_mds_session *session)
2640 {
2641         struct ceph_mds_request *req, *nreq;
2642         int err;
2643
2644         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2645
2646         mutex_lock(&mdsc->mutex);
2647         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2648                 err = __prepare_send_request(mdsc, req, session->s_mds);
2649                 if (!err) {
2650                         ceph_msg_get(req->r_request);
2651                         ceph_con_send(&session->s_con, req->r_request);
2652                 }
2653         }
2654         mutex_unlock(&mdsc->mutex);
2655 }
2656
2657 /*
2658  * Encode information about a cap for a reconnect with the MDS.
2659  */
2660 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2661                           void *arg)
2662 {
2663         union {
2664                 struct ceph_mds_cap_reconnect v2;
2665                 struct ceph_mds_cap_reconnect_v1 v1;
2666         } rec;
2667         size_t reclen;
2668         struct ceph_inode_info *ci;
2669         struct ceph_reconnect_state *recon_state = arg;
2670         struct ceph_pagelist *pagelist = recon_state->pagelist;
2671         char *path;
2672         int pathlen, err;
2673         u64 pathbase;
2674         struct dentry *dentry;
2675
2676         ci = cap->ci;
2677
2678         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2679              inode, ceph_vinop(inode), cap, cap->cap_id,
2680              ceph_cap_string(cap->issued));
2681         err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2682         if (err)
2683                 return err;
2684
2685         dentry = d_find_alias(inode);
2686         if (dentry) {
2687                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2688                 if (IS_ERR(path)) {
2689                         err = PTR_ERR(path);
2690                         goto out_dput;
2691                 }
2692         } else {
2693                 path = NULL;
2694                 pathlen = 0;
2695         }
2696         err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2697         if (err)
2698                 goto out_free;
2699
2700         spin_lock(&ci->i_ceph_lock);
2701         cap->seq = 0;        /* reset cap seq */
2702         cap->issue_seq = 0;  /* and issue_seq */
2703         cap->mseq = 0;       /* and migrate_seq */
2704         cap->cap_gen = cap->session->s_cap_gen;
2705
2706         if (recon_state->flock) {
2707                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2708                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2709                 rec.v2.issued = cpu_to_le32(cap->issued);
2710                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2711                 rec.v2.pathbase = cpu_to_le64(pathbase);
2712                 rec.v2.flock_len = 0;
2713                 reclen = sizeof(rec.v2);
2714         } else {
2715                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2716                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2717                 rec.v1.issued = cpu_to_le32(cap->issued);
2718                 rec.v1.size = cpu_to_le64(inode->i_size);
2719                 ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2720                 ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2721                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2722                 rec.v1.pathbase = cpu_to_le64(pathbase);
2723                 reclen = sizeof(rec.v1);
2724         }
2725         spin_unlock(&ci->i_ceph_lock);
2726
2727         if (recon_state->flock) {
2728                 int num_fcntl_locks, num_flock_locks;
2729                 struct ceph_filelock *flocks;
2730
2731 encode_again:
2732                 spin_lock(&inode->i_lock);
2733                 ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2734                 spin_unlock(&inode->i_lock);
2735                 flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2736                                  sizeof(struct ceph_filelock), GFP_NOFS);
2737                 if (!flocks) {
2738                         err = -ENOMEM;
2739                         goto out_free;
2740                 }
2741                 spin_lock(&inode->i_lock);
2742                 err = ceph_encode_locks_to_buffer(inode, flocks,
2743                                                   num_fcntl_locks,
2744                                                   num_flock_locks);
2745                 spin_unlock(&inode->i_lock);
2746                 if (err) {
2747                         kfree(flocks);
2748                         if (err == -ENOSPC)
2749                                 goto encode_again;
2750                         goto out_free;
2751                 }
2752                 /*
2753                  * number of encoded locks is stable, so copy to pagelist
2754                  */
2755                 rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2756                                     (num_fcntl_locks+num_flock_locks) *
2757                                     sizeof(struct ceph_filelock));
2758                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2759                 if (!err)
2760                         err = ceph_locks_to_pagelist(flocks, pagelist,
2761                                                      num_fcntl_locks,
2762                                                      num_flock_locks);
2763                 kfree(flocks);
2764         } else {
2765                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2766         }
2767
2768         recon_state->nr_caps++;
2769 out_free:
2770         kfree(path);
2771 out_dput:
2772         dput(dentry);
2773         return err;
2774 }
2775
2776
2777 /*
2778  * If an MDS fails and recovers, clients need to reconnect in order to
2779  * reestablish shared state.  This includes all caps issued through
2780  * this session _and_ the snap_realm hierarchy.  Because it's not
2781  * clear which snap realms the mds cares about, we send everything we
2782  * know about.. that ensures we'll then get any new info the
2783  * recovering MDS might have.
2784  *
2785  * This is a relatively heavyweight operation, but it's rare.
2786  *
2787  * called with mdsc->mutex held.
2788  */
2789 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2790                                struct ceph_mds_session *session)
2791 {
2792         struct ceph_msg *reply;
2793         struct rb_node *p;
2794         int mds = session->s_mds;
2795         int err = -ENOMEM;
2796         int s_nr_caps;
2797         struct ceph_pagelist *pagelist;
2798         struct ceph_reconnect_state recon_state;
2799
2800         pr_info("mds%d reconnect start\n", mds);
2801
2802         pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2803         if (!pagelist)
2804                 goto fail_nopagelist;
2805         ceph_pagelist_init(pagelist);
2806
2807         reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2808         if (!reply)
2809                 goto fail_nomsg;
2810
2811         mutex_lock(&session->s_mutex);
2812         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2813         session->s_seq = 0;
2814
2815         dout("session %p state %s\n", session,
2816              ceph_session_state_name(session->s_state));
2817
2818         spin_lock(&session->s_gen_ttl_lock);
2819         session->s_cap_gen++;
2820         spin_unlock(&session->s_gen_ttl_lock);
2821
2822         spin_lock(&session->s_cap_lock);
2823         /* don't know if session is readonly */
2824         session->s_readonly = 0;
2825         /*
2826          * notify __ceph_remove_cap() that we are composing cap reconnect.
2827          * If a cap get released before being added to the cap reconnect,
2828          * __ceph_remove_cap() should skip queuing cap release.
2829          */
2830         session->s_cap_reconnect = 1;
2831         /* drop old cap expires; we're about to reestablish that state */
2832         discard_cap_releases(mdsc, session);
2833         spin_unlock(&session->s_cap_lock);
2834
2835         /* trim unused caps to reduce MDS's cache rejoin time */
2836         shrink_dcache_parent(mdsc->fsc->sb->s_root);
2837
2838         ceph_con_close(&session->s_con);
2839         ceph_con_open(&session->s_con,
2840                       CEPH_ENTITY_TYPE_MDS, mds,
2841                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2842
2843         /* replay unsafe requests */
2844         replay_unsafe_requests(mdsc, session);
2845
2846         down_read(&mdsc->snap_rwsem);
2847
2848         /* traverse this session's caps */
2849         s_nr_caps = session->s_nr_caps;
2850         err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2851         if (err)
2852                 goto fail;
2853
2854         recon_state.nr_caps = 0;
2855         recon_state.pagelist = pagelist;
2856         recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2857         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2858         if (err < 0)
2859                 goto fail;
2860
2861         spin_lock(&session->s_cap_lock);
2862         session->s_cap_reconnect = 0;
2863         spin_unlock(&session->s_cap_lock);
2864
2865         /*
2866          * snaprealms.  we provide mds with the ino, seq (version), and
2867          * parent for all of our realms.  If the mds has any newer info,
2868          * it will tell us.
2869          */
2870         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2871                 struct ceph_snap_realm *realm =
2872                         rb_entry(p, struct ceph_snap_realm, node);
2873                 struct ceph_mds_snaprealm_reconnect sr_rec;
2874
2875                 dout(" adding snap realm %llx seq %lld parent %llx\n",
2876                      realm->ino, realm->seq, realm->parent_ino);
2877                 sr_rec.ino = cpu_to_le64(realm->ino);
2878                 sr_rec.seq = cpu_to_le64(realm->seq);
2879                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
2880                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2881                 if (err)
2882                         goto fail;
2883         }
2884
2885         if (recon_state.flock)
2886                 reply->hdr.version = cpu_to_le16(2);
2887
2888         /* raced with cap release? */
2889         if (s_nr_caps != recon_state.nr_caps) {
2890                 struct page *page = list_first_entry(&pagelist->head,
2891                                                      struct page, lru);
2892                 __le32 *addr = kmap_atomic(page);
2893                 *addr = cpu_to_le32(recon_state.nr_caps);
2894                 kunmap_atomic(addr);
2895         }
2896
2897         reply->hdr.data_len = cpu_to_le32(pagelist->length);
2898         ceph_msg_data_add_pagelist(reply, pagelist);
2899         ceph_con_send(&session->s_con, reply);
2900
2901         mutex_unlock(&session->s_mutex);
2902
2903         mutex_lock(&mdsc->mutex);
2904         __wake_requests(mdsc, &session->s_waiting);
2905         mutex_unlock(&mdsc->mutex);
2906
2907         up_read(&mdsc->snap_rwsem);
2908         return;
2909
2910 fail:
2911         ceph_msg_put(reply);
2912         up_read(&mdsc->snap_rwsem);
2913         mutex_unlock(&session->s_mutex);
2914 fail_nomsg:
2915         ceph_pagelist_release(pagelist);
2916 fail_nopagelist:
2917         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
2918         return;
2919 }
2920
2921
2922 /*
2923  * compare old and new mdsmaps, kicking requests
2924  * and closing out old connections as necessary
2925  *
2926  * called under mdsc->mutex.
2927  */
2928 static void check_new_map(struct ceph_mds_client *mdsc,
2929                           struct ceph_mdsmap *newmap,
2930                           struct ceph_mdsmap *oldmap)
2931 {
2932         int i;
2933         int oldstate, newstate;
2934         struct ceph_mds_session *s;
2935
2936         dout("check_new_map new %u old %u\n",
2937              newmap->m_epoch, oldmap->m_epoch);
2938
2939         for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
2940                 if (mdsc->sessions[i] == NULL)
2941                         continue;
2942                 s = mdsc->sessions[i];
2943                 oldstate = ceph_mdsmap_get_state(oldmap, i);
2944                 newstate = ceph_mdsmap_get_state(newmap, i);
2945
2946                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
2947                      i, ceph_mds_state_name(oldstate),
2948                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
2949                      ceph_mds_state_name(newstate),
2950                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
2951                      ceph_session_state_name(s->s_state));
2952
2953                 if (i >= newmap->m_max_mds ||
2954                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
2955                            ceph_mdsmap_get_addr(newmap, i),
2956                            sizeof(struct ceph_entity_addr))) {
2957                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
2958                                 /* the session never opened, just close it
2959                                  * out now */
2960                                 __wake_requests(mdsc, &s->s_waiting);
2961                                 __unregister_session(mdsc, s);
2962                         } else {
2963                                 /* just close it */
2964                                 mutex_unlock(&mdsc->mutex);
2965                                 mutex_lock(&s->s_mutex);
2966                                 mutex_lock(&mdsc->mutex);
2967                                 ceph_con_close(&s->s_con);
2968                                 mutex_unlock(&s->s_mutex);
2969                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
2970                         }
2971
2972                         /* kick any requests waiting on the recovering mds */
2973                         kick_requests(mdsc, i);
2974                 } else if (oldstate == newstate) {
2975                         continue;  /* nothing new with this mds */
2976                 }
2977
2978                 /*
2979                  * send reconnect?
2980                  */
2981                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
2982                     newstate >= CEPH_MDS_STATE_RECONNECT) {
2983                         mutex_unlock(&mdsc->mutex);
2984                         send_mds_reconnect(mdsc, s);
2985                         mutex_lock(&mdsc->mutex);
2986                 }
2987
2988                 /*
2989                  * kick request on any mds that has gone active.
2990                  */
2991                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
2992                     newstate >= CEPH_MDS_STATE_ACTIVE) {
2993                         if (oldstate != CEPH_MDS_STATE_CREATING &&
2994                             oldstate != CEPH_MDS_STATE_STARTING)
2995                                 pr_info("mds%d recovery completed\n", s->s_mds);
2996                         kick_requests(mdsc, i);
2997                         ceph_kick_flushing_caps(mdsc, s);
2998                         wake_up_session_caps(s, 1);
2999                 }
3000         }
3001
3002         for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3003                 s = mdsc->sessions[i];
3004                 if (!s)
3005                         continue;
3006                 if (!ceph_mdsmap_is_laggy(newmap, i))
3007                         continue;
3008                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3009                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3010                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3011                         dout(" connecting to export targets of laggy mds%d\n",
3012                              i);
3013                         __open_export_target_sessions(mdsc, s);
3014                 }
3015         }
3016 }
3017
3018
3019
3020 /*
3021  * leases
3022  */
3023
3024 /*
3025  * caller must hold session s_mutex, dentry->d_lock
3026  */
3027 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3028 {
3029         struct ceph_dentry_info *di = ceph_dentry(dentry);
3030
3031         ceph_put_mds_session(di->lease_session);
3032         di->lease_session = NULL;
3033 }
3034
3035 static void handle_lease(struct ceph_mds_client *mdsc,
3036                          struct ceph_mds_session *session,
3037                          struct ceph_msg *msg)
3038 {
3039         struct super_block *sb = mdsc->fsc->sb;
3040         struct inode *inode;
3041         struct dentry *parent, *dentry;
3042         struct ceph_dentry_info *di;
3043         int mds = session->s_mds;
3044         struct ceph_mds_lease *h = msg->front.iov_base;
3045         u32 seq;
3046         struct ceph_vino vino;
3047         struct qstr dname;
3048         int release = 0;
3049
3050         dout("handle_lease from mds%d\n", mds);
3051
3052         /* decode */
3053         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3054                 goto bad;
3055         vino.ino = le64_to_cpu(h->ino);
3056         vino.snap = CEPH_NOSNAP;
3057         seq = le32_to_cpu(h->seq);
3058         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3059         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3060         if (dname.len != get_unaligned_le32(h+1))
3061                 goto bad;
3062
3063         /* lookup inode */
3064         inode = ceph_find_inode(sb, vino);
3065         dout("handle_lease %s, ino %llx %p %.*s\n",
3066              ceph_lease_op_name(h->action), vino.ino, inode,
3067              dname.len, dname.name);
3068
3069         mutex_lock(&session->s_mutex);
3070         session->s_seq++;
3071
3072         if (inode == NULL) {
3073                 dout("handle_lease no inode %llx\n", vino.ino);
3074                 goto release;
3075         }
3076
3077         /* dentry */
3078         parent = d_find_alias(inode);
3079         if (!parent) {
3080                 dout("no parent dentry on inode %p\n", inode);
3081                 WARN_ON(1);
3082                 goto release;  /* hrm... */
3083         }
3084         dname.hash = full_name_hash(dname.name, dname.len);
3085         dentry = d_lookup(parent, &dname);
3086         dput(parent);
3087         if (!dentry)
3088                 goto release;
3089
3090         spin_lock(&dentry->d_lock);
3091         di = ceph_dentry(dentry);
3092         switch (h->action) {
3093         case CEPH_MDS_LEASE_REVOKE:
3094                 if (di->lease_session == session) {
3095                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3096                                 h->seq = cpu_to_le32(di->lease_seq);
3097                         __ceph_mdsc_drop_dentry_lease(dentry);
3098                 }
3099                 release = 1;
3100                 break;
3101
3102         case CEPH_MDS_LEASE_RENEW:
3103                 if (di->lease_session == session &&
3104                     di->lease_gen == session->s_cap_gen &&
3105                     di->lease_renew_from &&
3106                     di->lease_renew_after == 0) {
3107                         unsigned long duration =
3108                                 le32_to_cpu(h->duration_ms) * HZ / 1000;
3109
3110                         di->lease_seq = seq;
3111                         dentry->d_time = di->lease_renew_from + duration;
3112                         di->lease_renew_after = di->lease_renew_from +
3113                                 (duration >> 1);
3114                         di->lease_renew_from = 0;
3115                 }
3116                 break;
3117         }
3118         spin_unlock(&dentry->d_lock);
3119         dput(dentry);
3120
3121         if (!release)
3122                 goto out;
3123
3124 release:
3125         /* let's just reuse the same message */
3126         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3127         ceph_msg_get(msg);
3128         ceph_con_send(&session->s_con, msg);
3129
3130 out:
3131         iput(inode);
3132         mutex_unlock(&session->s_mutex);
3133         return;
3134
3135 bad:
3136         pr_err("corrupt lease message\n");
3137         ceph_msg_dump(msg);
3138 }
3139
3140 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3141                               struct inode *inode,
3142                               struct dentry *dentry, char action,
3143                               u32 seq)
3144 {
3145         struct ceph_msg *msg;
3146         struct ceph_mds_lease *lease;
3147         int len = sizeof(*lease) + sizeof(u32);
3148         int dnamelen = 0;
3149
3150         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3151              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3152         dnamelen = dentry->d_name.len;
3153         len += dnamelen;
3154
3155         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3156         if (!msg)
3157                 return;
3158         lease = msg->front.iov_base;
3159         lease->action = action;
3160         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3161         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3162         lease->seq = cpu_to_le32(seq);
3163         put_unaligned_le32(dnamelen, lease + 1);
3164         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3165
3166         /*
3167          * if this is a preemptive lease RELEASE, no need to
3168          * flush request stream, since the actual request will
3169          * soon follow.
3170          */
3171         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3172
3173         ceph_con_send(&session->s_con, msg);
3174 }
3175
3176 /*
3177  * Preemptively release a lease we expect to invalidate anyway.
3178  * Pass @inode always, @dentry is optional.
3179  */
3180 void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
3181                              struct dentry *dentry)
3182 {
3183         struct ceph_dentry_info *di;
3184         struct ceph_mds_session *session;
3185         u32 seq;
3186
3187         BUG_ON(inode == NULL);
3188         BUG_ON(dentry == NULL);
3189
3190         /* is dentry lease valid? */
3191         spin_lock(&dentry->d_lock);
3192         di = ceph_dentry(dentry);
3193         if (!di || !di->lease_session ||
3194             di->lease_session->s_mds < 0 ||
3195             di->lease_gen != di->lease_session->s_cap_gen ||
3196             !time_before(jiffies, dentry->d_time)) {
3197                 dout("lease_release inode %p dentry %p -- "
3198                      "no lease\n",
3199                      inode, dentry);
3200                 spin_unlock(&dentry->d_lock);
3201                 return;
3202         }
3203
3204         /* we do have a lease on this dentry; note mds and seq */
3205         session = ceph_get_mds_session(di->lease_session);
3206         seq = di->lease_seq;
3207         __ceph_mdsc_drop_dentry_lease(dentry);
3208         spin_unlock(&dentry->d_lock);
3209
3210         dout("lease_release inode %p dentry %p to mds%d\n",
3211              inode, dentry, session->s_mds);
3212         ceph_mdsc_lease_send_msg(session, inode, dentry,
3213                                  CEPH_MDS_LEASE_RELEASE, seq);
3214         ceph_put_mds_session(session);
3215 }
3216
3217 /*
3218  * drop all leases (and dentry refs) in preparation for umount
3219  */
3220 static void drop_leases(struct ceph_mds_client *mdsc)
3221 {
3222         int i;
3223
3224         dout("drop_leases\n");
3225         mutex_lock(&mdsc->mutex);
3226         for (i = 0; i < mdsc->max_sessions; i++) {
3227                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3228                 if (!s)
3229                         continue;
3230                 mutex_unlock(&mdsc->mutex);
3231                 mutex_lock(&s->s_mutex);
3232                 mutex_unlock(&s->s_mutex);
3233                 ceph_put_mds_session(s);
3234                 mutex_lock(&mdsc->mutex);
3235         }
3236         mutex_unlock(&mdsc->mutex);
3237 }
3238
3239
3240
3241 /*
3242  * delayed work -- periodically trim expired leases, renew caps with mds
3243  */
3244 static void schedule_delayed(struct ceph_mds_client *mdsc)
3245 {
3246         int delay = 5;
3247         unsigned hz = round_jiffies_relative(HZ * delay);
3248         schedule_delayed_work(&mdsc->delayed_work, hz);
3249 }
3250
3251 static void delayed_work(struct work_struct *work)
3252 {
3253         int i;
3254         struct ceph_mds_client *mdsc =
3255                 container_of(work, struct ceph_mds_client, delayed_work.work);
3256         int renew_interval;
3257         int renew_caps;
3258
3259         dout("mdsc delayed_work\n");
3260         ceph_check_delayed_caps(mdsc);
3261
3262         mutex_lock(&mdsc->mutex);
3263         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3264         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3265                                    mdsc->last_renew_caps);
3266         if (renew_caps)
3267                 mdsc->last_renew_caps = jiffies;
3268
3269         for (i = 0; i < mdsc->max_sessions; i++) {
3270                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3271                 if (s == NULL)
3272                         continue;
3273                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3274                         dout("resending session close request for mds%d\n",
3275                              s->s_mds);
3276                         request_close_session(mdsc, s);
3277                         ceph_put_mds_session(s);
3278                         continue;
3279                 }
3280                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3281                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3282                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3283                                 pr_info("mds%d hung\n", s->s_mds);
3284                         }
3285                 }
3286                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3287                         /* this mds is failed or recovering, just wait */
3288                         ceph_put_mds_session(s);
3289                         continue;
3290                 }
3291                 mutex_unlock(&mdsc->mutex);
3292
3293                 mutex_lock(&s->s_mutex);
3294                 if (renew_caps)
3295                         send_renew_caps(mdsc, s);
3296                 else
3297                         ceph_con_keepalive(&s->s_con);
3298                 ceph_add_cap_releases(mdsc, s);
3299                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3300                     s->s_state == CEPH_MDS_SESSION_HUNG)
3301                         ceph_send_cap_releases(mdsc, s);
3302                 mutex_unlock(&s->s_mutex);
3303                 ceph_put_mds_session(s);
3304
3305                 mutex_lock(&mdsc->mutex);
3306         }
3307         mutex_unlock(&mdsc->mutex);
3308
3309         schedule_delayed(mdsc);
3310 }
3311
3312 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3313
3314 {
3315         struct ceph_mds_client *mdsc;
3316
3317         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3318         if (!mdsc)
3319                 return -ENOMEM;
3320         mdsc->fsc = fsc;
3321         fsc->mdsc = mdsc;
3322         mutex_init(&mdsc->mutex);
3323         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3324         if (mdsc->mdsmap == NULL) {
3325                 kfree(mdsc);
3326                 return -ENOMEM;
3327         }
3328
3329         init_completion(&mdsc->safe_umount_waiters);
3330         init_waitqueue_head(&mdsc->session_close_wq);
3331         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3332         mdsc->sessions = NULL;
3333         atomic_set(&mdsc->num_sessions, 0);
3334         mdsc->max_sessions = 0;
3335         mdsc->stopping = 0;
3336         init_rwsem(&mdsc->snap_rwsem);
3337         mdsc->snap_realms = RB_ROOT;
3338         INIT_LIST_HEAD(&mdsc->snap_empty);
3339         spin_lock_init(&mdsc->snap_empty_lock);
3340         mdsc->last_tid = 0;
3341         mdsc->request_tree = RB_ROOT;
3342         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3343         mdsc->last_renew_caps = jiffies;
3344         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3345         spin_lock_init(&mdsc->cap_delay_lock);
3346         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3347         spin_lock_init(&mdsc->snap_flush_lock);
3348         mdsc->cap_flush_seq = 0;
3349         INIT_LIST_HEAD(&mdsc->cap_dirty);
3350         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3351         mdsc->num_cap_flushing = 0;
3352         spin_lock_init(&mdsc->cap_dirty_lock);
3353         init_waitqueue_head(&mdsc->cap_flushing_wq);
3354         spin_lock_init(&mdsc->dentry_lru_lock);
3355         INIT_LIST_HEAD(&mdsc->dentry_lru);
3356
3357         ceph_caps_init(mdsc);
3358         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3359
3360         return 0;
3361 }
3362
3363 /*
3364  * Wait for safe replies on open mds requests.  If we time out, drop
3365  * all requests from the tree to avoid dangling dentry refs.
3366  */
3367 static void wait_requests(struct ceph_mds_client *mdsc)
3368 {
3369         struct ceph_mds_request *req;
3370         struct ceph_fs_client *fsc = mdsc->fsc;
3371
3372         mutex_lock(&mdsc->mutex);
3373         if (__get_oldest_req(mdsc)) {
3374                 mutex_unlock(&mdsc->mutex);
3375
3376                 dout("wait_requests waiting for requests\n");
3377                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3378                                     fsc->client->options->mount_timeout * HZ);
3379
3380                 /* tear down remaining requests */
3381                 mutex_lock(&mdsc->mutex);
3382                 while ((req = __get_oldest_req(mdsc))) {
3383                         dout("wait_requests timed out on tid %llu\n",
3384                              req->r_tid);
3385                         __unregister_request(mdsc, req);
3386                 }
3387         }
3388         mutex_unlock(&mdsc->mutex);
3389         dout("wait_requests done\n");
3390 }
3391
3392 /*
3393  * called before mount is ro, and before dentries are torn down.
3394  * (hmm, does this still race with new lookups?)
3395  */
3396 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3397 {
3398         dout("pre_umount\n");
3399         mdsc->stopping = 1;
3400
3401         drop_leases(mdsc);
3402         ceph_flush_dirty_caps(mdsc);
3403         wait_requests(mdsc);
3404
3405         /*
3406          * wait for reply handlers to drop their request refs and
3407          * their inode/dcache refs
3408          */
3409         ceph_msgr_flush();
3410 }
3411
3412 /*
3413  * wait for all write mds requests to flush.
3414  */
3415 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3416 {
3417         struct ceph_mds_request *req = NULL, *nextreq;
3418         struct rb_node *n;
3419
3420         mutex_lock(&mdsc->mutex);
3421         dout("wait_unsafe_requests want %lld\n", want_tid);
3422 restart:
3423         req = __get_oldest_req(mdsc);
3424         while (req && req->r_tid <= want_tid) {
3425                 /* find next request */
3426                 n = rb_next(&req->r_node);
3427                 if (n)
3428                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3429                 else
3430                         nextreq = NULL;
3431                 if ((req->r_op & CEPH_MDS_OP_WRITE)) {
3432                         /* write op */
3433                         ceph_mdsc_get_request(req);
3434                         if (nextreq)
3435                                 ceph_mdsc_get_request(nextreq);
3436                         mutex_unlock(&mdsc->mutex);
3437                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3438                              req->r_tid, want_tid);
3439                         wait_for_completion(&req->r_safe_completion);
3440                         mutex_lock(&mdsc->mutex);
3441                         ceph_mdsc_put_request(req);
3442                         if (!nextreq)
3443                                 break;  /* next dne before, so we're done! */
3444                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3445                                 /* next request was removed from tree */
3446                                 ceph_mdsc_put_request(nextreq);
3447                                 goto restart;
3448                         }
3449                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3450                 }
3451                 req = nextreq;
3452         }
3453         mutex_unlock(&mdsc->mutex);
3454         dout("wait_unsafe_requests done\n");
3455 }
3456
3457 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3458 {
3459         u64 want_tid, want_flush;
3460
3461         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3462                 return;
3463
3464         dout("sync\n");
3465         mutex_lock(&mdsc->mutex);
3466         want_tid = mdsc->last_tid;
3467         mutex_unlock(&mdsc->mutex);
3468
3469         ceph_flush_dirty_caps(mdsc);
3470         spin_lock(&mdsc->cap_dirty_lock);
3471         want_flush = mdsc->cap_flush_seq;
3472         spin_unlock(&mdsc->cap_dirty_lock);
3473
3474         dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush);
3475
3476         wait_unsafe_requests(mdsc, want_tid);
3477         wait_caps_flush(mdsc, want_flush);
3478 }
3479
3480 /*
3481  * true if all sessions are closed, or we force unmount
3482  */
3483 static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3484 {
3485         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3486                 return true;
3487         return atomic_read(&mdsc->num_sessions) == 0;
3488 }
3489
3490 /*
3491  * called after sb is ro.
3492  */
3493 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3494 {
3495         struct ceph_mds_session *session;
3496         int i;
3497         struct ceph_fs_client *fsc = mdsc->fsc;
3498         unsigned long timeout = fsc->client->options->mount_timeout * HZ;
3499
3500         dout("close_sessions\n");
3501
3502         /* close sessions */
3503         mutex_lock(&mdsc->mutex);
3504         for (i = 0; i < mdsc->max_sessions; i++) {
3505                 session = __ceph_lookup_mds_session(mdsc, i);
3506                 if (!session)
3507                         continue;
3508                 mutex_unlock(&mdsc->mutex);
3509                 mutex_lock(&session->s_mutex);
3510                 __close_session(mdsc, session);
3511                 mutex_unlock(&session->s_mutex);
3512                 ceph_put_mds_session(session);
3513                 mutex_lock(&mdsc->mutex);
3514         }
3515         mutex_unlock(&mdsc->mutex);
3516
3517         dout("waiting for sessions to close\n");
3518         wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3519                            timeout);
3520
3521         /* tear down remaining sessions */
3522         mutex_lock(&mdsc->mutex);
3523         for (i = 0; i < mdsc->max_sessions; i++) {
3524                 if (mdsc->sessions[i]) {
3525                         session = get_session(mdsc->sessions[i]);
3526                         __unregister_session(mdsc, session);
3527                         mutex_unlock(&mdsc->mutex);
3528                         mutex_lock(&session->s_mutex);
3529                         remove_session_caps(session);
3530                         mutex_unlock(&session->s_mutex);
3531                         ceph_put_mds_session(session);
3532                         mutex_lock(&mdsc->mutex);
3533                 }
3534         }
3535         WARN_ON(!list_empty(&mdsc->cap_delay_list));
3536         mutex_unlock(&mdsc->mutex);
3537
3538         ceph_cleanup_empty_realms(mdsc);
3539
3540         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3541
3542         dout("stopped\n");
3543 }
3544
3545 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3546 {
3547         dout("stop\n");
3548         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3549         if (mdsc->mdsmap)
3550                 ceph_mdsmap_destroy(mdsc->mdsmap);
3551         kfree(mdsc->sessions);
3552         ceph_caps_finalize(mdsc);
3553 }
3554
3555 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3556 {
3557         struct ceph_mds_client *mdsc = fsc->mdsc;
3558
3559         dout("mdsc_destroy %p\n", mdsc);
3560         ceph_mdsc_stop(mdsc);
3561
3562         /* flush out any connection work with references to us */
3563         ceph_msgr_flush();
3564
3565         fsc->mdsc = NULL;
3566         kfree(mdsc);
3567         dout("mdsc_destroy %p done\n", mdsc);
3568 }
3569
3570
3571 /*
3572  * handle mds map update.
3573  */
3574 void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3575 {
3576         u32 epoch;
3577         u32 maplen;
3578         void *p = msg->front.iov_base;
3579         void *end = p + msg->front.iov_len;
3580         struct ceph_mdsmap *newmap, *oldmap;
3581         struct ceph_fsid fsid;
3582         int err = -EINVAL;
3583
3584         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3585         ceph_decode_copy(&p, &fsid, sizeof(fsid));
3586         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3587                 return;
3588         epoch = ceph_decode_32(&p);
3589         maplen = ceph_decode_32(&p);
3590         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3591
3592         /* do we need it? */
3593         ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
3594         mutex_lock(&mdsc->mutex);
3595         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3596                 dout("handle_map epoch %u <= our %u\n",
3597                      epoch, mdsc->mdsmap->m_epoch);
3598                 mutex_unlock(&mdsc->mutex);
3599                 return;
3600         }
3601
3602         newmap = ceph_mdsmap_decode(&p, end);
3603         if (IS_ERR(newmap)) {
3604                 err = PTR_ERR(newmap);
3605                 goto bad_unlock;
3606         }
3607
3608         /* swap into place */
3609         if (mdsc->mdsmap) {
3610                 oldmap = mdsc->mdsmap;
3611                 mdsc->mdsmap = newmap;
3612                 check_new_map(mdsc, newmap, oldmap);
3613                 ceph_mdsmap_destroy(oldmap);
3614         } else {
3615                 mdsc->mdsmap = newmap;  /* first mds map */
3616         }
3617         mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3618
3619         __wake_requests(mdsc, &mdsc->waiting_for_map);
3620
3621         mutex_unlock(&mdsc->mutex);
3622         schedule_delayed(mdsc);
3623         return;
3624
3625 bad_unlock:
3626         mutex_unlock(&mdsc->mutex);
3627 bad:
3628         pr_err("error decoding mdsmap %d\n", err);
3629         return;
3630 }
3631
3632 static struct ceph_connection *con_get(struct ceph_connection *con)
3633 {
3634         struct ceph_mds_session *s = con->private;
3635
3636         if (get_session(s)) {
3637                 dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3638                 return con;
3639         }
3640         dout("mdsc con_get %p FAIL\n", s);
3641         return NULL;
3642 }
3643
3644 static void con_put(struct ceph_connection *con)
3645 {
3646         struct ceph_mds_session *s = con->private;
3647
3648         dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3649         ceph_put_mds_session(s);
3650 }
3651
3652 /*
3653  * if the client is unresponsive for long enough, the mds will kill
3654  * the session entirely.
3655  */
3656 static void peer_reset(struct ceph_connection *con)
3657 {
3658         struct ceph_mds_session *s = con->private;
3659         struct ceph_mds_client *mdsc = s->s_mdsc;
3660
3661         pr_warn("mds%d closed our session\n", s->s_mds);
3662         send_mds_reconnect(mdsc, s);
3663 }
3664
3665 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3666 {
3667         struct ceph_mds_session *s = con->private;
3668         struct ceph_mds_client *mdsc = s->s_mdsc;
3669         int type = le16_to_cpu(msg->hdr.type);
3670
3671         mutex_lock(&mdsc->mutex);
3672         if (__verify_registered_session(mdsc, s) < 0) {
3673                 mutex_unlock(&mdsc->mutex);
3674                 goto out;
3675         }
3676         mutex_unlock(&mdsc->mutex);
3677
3678         switch (type) {
3679         case CEPH_MSG_MDS_MAP:
3680                 ceph_mdsc_handle_map(mdsc, msg);
3681                 break;
3682         case CEPH_MSG_CLIENT_SESSION:
3683                 handle_session(s, msg);
3684                 break;
3685         case CEPH_MSG_CLIENT_REPLY:
3686                 handle_reply(s, msg);
3687                 break;
3688         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3689                 handle_forward(mdsc, s, msg);
3690                 break;
3691         case CEPH_MSG_CLIENT_CAPS:
3692                 ceph_handle_caps(s, msg);
3693                 break;
3694         case CEPH_MSG_CLIENT_SNAP:
3695                 ceph_handle_snap(mdsc, s, msg);
3696                 break;
3697         case CEPH_MSG_CLIENT_LEASE:
3698                 handle_lease(mdsc, s, msg);
3699                 break;
3700
3701         default:
3702                 pr_err("received unknown message type %d %s\n", type,
3703                        ceph_msg_type_name(type));
3704         }
3705 out:
3706         ceph_msg_put(msg);
3707 }
3708
3709 /*
3710  * authentication
3711  */
3712
3713 /*
3714  * Note: returned pointer is the address of a structure that's
3715  * managed separately.  Caller must *not* attempt to free it.
3716  */
3717 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3718                                         int *proto, int force_new)
3719 {
3720         struct ceph_mds_session *s = con->private;
3721         struct ceph_mds_client *mdsc = s->s_mdsc;
3722         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3723         struct ceph_auth_handshake *auth = &s->s_auth;
3724
3725         if (force_new && auth->authorizer) {
3726                 ceph_auth_destroy_authorizer(ac, auth->authorizer);
3727                 auth->authorizer = NULL;
3728         }
3729         if (!auth->authorizer) {
3730                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3731                                                       auth);
3732                 if (ret)
3733                         return ERR_PTR(ret);
3734         } else {
3735                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3736                                                       auth);
3737                 if (ret)
3738                         return ERR_PTR(ret);
3739         }
3740         *proto = ac->protocol;
3741
3742         return auth;
3743 }
3744
3745
3746 static int verify_authorizer_reply(struct ceph_connection *con, int len)
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
3752         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3753 }
3754
3755 static int invalidate_authorizer(struct ceph_connection *con)
3756 {
3757         struct ceph_mds_session *s = con->private;
3758         struct ceph_mds_client *mdsc = s->s_mdsc;
3759         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3760
3761         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3762
3763         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3764 }
3765
3766 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3767                                 struct ceph_msg_header *hdr, int *skip)
3768 {
3769         struct ceph_msg *msg;
3770         int type = (int) le16_to_cpu(hdr->type);
3771         int front_len = (int) le32_to_cpu(hdr->front_len);
3772
3773         if (con->in_msg)
3774                 return con->in_msg;
3775
3776         *skip = 0;
3777         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3778         if (!msg) {
3779                 pr_err("unable to allocate msg type %d len %d\n",
3780                        type, front_len);
3781                 return NULL;
3782         }
3783
3784         return msg;
3785 }
3786
3787 static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
3788 {
3789        struct ceph_mds_session *s = con->private;
3790        struct ceph_auth_handshake *auth = &s->s_auth;
3791        return ceph_auth_sign_message(auth, msg);
3792 }
3793
3794 static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
3795 {
3796        struct ceph_mds_session *s = con->private;
3797        struct ceph_auth_handshake *auth = &s->s_auth;
3798        return ceph_auth_check_message_signature(auth, msg);
3799 }
3800
3801 static const struct ceph_connection_operations mds_con_ops = {
3802         .get = con_get,
3803         .put = con_put,
3804         .dispatch = dispatch,
3805         .get_authorizer = get_authorizer,
3806         .verify_authorizer_reply = verify_authorizer_reply,
3807         .invalidate_authorizer = invalidate_authorizer,
3808         .peer_reset = peer_reset,
3809         .alloc_msg = mds_alloc_msg,
3810         .sign_message = sign_message,
3811         .check_message_signature = check_message_signature,
3812 };
3813
3814 /* eof */