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  44  * are no longer valid.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_flushing);
 462         INIT_LIST_HEAD(&s->s_cap_snaps_flushing);
 463
 464         dout("register_session mds%d\n", mds);
 465         if (mds >= mdsc->max_sessions) {
 466                 int newmax = 1 << get_count_order(mds+1);
 467                 struct ceph_mds_session **sa;
 468
 469                 dout("register_session realloc to %d\n", newmax);
 470                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 471                 if (sa == NULL)
 472                         goto fail_realloc;
 473                 if (mdsc->sessions) {
 474                         memcpy(sa, mdsc->sessions,
 475                                mdsc->max_sessions * sizeof(void *));
 476                         kfree(mdsc->sessions);
 477                 }
 478                 mdsc->sessions = sa;
 479                 mdsc->max_sessions = newmax;
 480         }
 481         mdsc->sessions[mds] = s;
 482         atomic_inc(&mdsc->num_sessions);
 483         atomic_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 484
 485         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 486                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 487
 488         return s;
 489
 490 fail_realloc:
 491         kfree(s);
 492         return ERR_PTR(-ENOMEM);
 493 }
 494
 495 /*
 496  * called under mdsc->mutex
 497  */
 498 static void __unregister_session(struct ceph_mds_client *mdsc,
 499                                struct ceph_mds_session *s)
 500 {
 501         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 502         BUG_ON(mdsc->sessions[s->s_mds] != s);
 503         mdsc->sessions[s->s_mds] = NULL;
 504         ceph_con_close(&s->s_con);
 505         ceph_put_mds_session(s);
 506         atomic_dec(&mdsc->num_sessions);
 507 }
 508
 509 /*
 510  * drop session refs in request.
 511  *
 512  * should be last request ref, or hold mdsc->mutex
 513  */
 514 static void put_request_session(struct ceph_mds_request *req)
 515 {
 516         if (req->r_session) {
 517                 ceph_put_mds_session(req->r_session);
 518                 req->r_session = NULL;
 519         }
 520 }
 521
 522 void ceph_mdsc_release_request(struct kref *kref)
 523 {
 524         struct ceph_mds_request *req = container_of(kref,
 525                                                     struct ceph_mds_request,
 526                                                     r_kref);
 527         destroy_reply_info(&req->r_reply_info);
 528         if (req->r_request)
 529                 ceph_msg_put(req->r_request);
 530         if (req->r_reply)
 531                 ceph_msg_put(req->r_reply);
 532         if (req->r_inode) {
 533                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 534                 iput(req->r_inode);
 535         }
 536         if (req->r_locked_dir)
 537                 ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
 538         iput(req->r_target_inode);
 539         if (req->r_dentry)
 540                 dput(req->r_dentry);
 541         if (req->r_old_dentry)
 542                 dput(req->r_old_dentry);
 543         if (req->r_old_dentry_dir) {
 544                 /*
 545                  * track (and drop pins for) r_old_dentry_dir
 546                  * separately, since r_old_dentry's d_parent may have
 547                  * changed between the dir mutex being dropped and
 548                  * this request being freed.
 549                  */
 550                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 551                                   CEPH_CAP_PIN);
 552                 iput(req->r_old_dentry_dir);
 553         }
 554         kfree(req->r_path1);
 555         kfree(req->r_path2);
 556         if (req->r_pagelist)
 557                 ceph_pagelist_release(req->r_pagelist);
 558         put_request_session(req);
 559         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 560         kfree(req);
 561 }
 562
 563 /*
 564  * lookup session, bump ref if found.
 565  *
 566  * called under mdsc->mutex.
 567  */
 568 static struct ceph_mds_request *__lookup_request(struct ceph_mds_client *mdsc,
 569                                              u64 tid)
 570 {
 571         struct ceph_mds_request *req;
 572         struct rb_node *n = mdsc->request_tree.rb_node;
 573
 574         while (n) {
 575                 req = rb_entry(n, struct ceph_mds_request, r_node);
 576                 if (tid < req->r_tid)
 577                         n = n->rb_left;
 578                 else if (tid > req->r_tid)
 579                         n = n->rb_right;
 580                 else {
 581                         ceph_mdsc_get_request(req);
 582                         return req;
 583                 }
 584         }
 585         return NULL;
 586 }
 587
 588 static void __insert_request(struct ceph_mds_client *mdsc,
 589                              struct ceph_mds_request *new)
 590 {
 591         struct rb_node **p = &mdsc->request_tree.rb_node;
 592         struct rb_node *parent = NULL;
 593         struct ceph_mds_request *req = NULL;
 594
 595         while (*p) {
 596                 parent = *p;
 597                 req = rb_entry(parent, struct ceph_mds_request, r_node);
 598                 if (new->r_tid < req->r_tid)
 599                         p = &(*p)->rb_left;
 600                 else if (new->r_tid > req->r_tid)
 601                         p = &(*p)->rb_right;
 602                 else
 603                         BUG();
 604         }
 605
 606         rb_link_node(&new->r_node, parent, p);
 607         rb_insert_color(&new->r_node, &mdsc->request_tree);
 608 }
 609
 610 /*
 611  * Register an in-flight request, and assign a tid.  Link to directory
 612  * are modifying (if any).
 613  *
 614  * Called under mdsc->mutex.
 615  */
 616 static void __register_request(struct ceph_mds_client *mdsc,
 617                                struct ceph_mds_request *req,
 618                                struct inode *dir)
 619 {
 620         req->r_tid = ++mdsc->last_tid;
 621         if (req->r_num_caps)
 622                 ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 623                                   req->r_num_caps);
 624         dout("__register_request %p tid %lld\n", req, req->r_tid);
 625         ceph_mdsc_get_request(req);
 626         __insert_request(mdsc, req);
 627
 628         req->r_uid = current_fsuid();
 629         req->r_gid = current_fsgid();
 630
 631         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 632                 mdsc->oldest_tid = req->r_tid;
 633
 634         if (dir) {
 635                 struct ceph_inode_info *ci = ceph_inode(dir);
 636
 637                 ihold(dir);
 638                 spin_lock(&ci->i_unsafe_lock);
 639                 req->r_unsafe_dir = dir;
 640                 list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 641                 spin_unlock(&ci->i_unsafe_lock);
 642         }
 643 }
 644
 645 static void __unregister_request(struct ceph_mds_client *mdsc,
 646                                  struct ceph_mds_request *req)
 647 {
 648         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 649
 650         if (req->r_tid == mdsc->oldest_tid) {
 651                 struct rb_node *p = rb_next(&req->r_node);
 652                 mdsc->oldest_tid = 0;
 653                 while (p) {
 654                         struct ceph_mds_request *next_req =
 655                                 rb_entry(p, struct ceph_mds_request, r_node);
 656                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 657                                 mdsc->oldest_tid = next_req->r_tid;
 658                                 break;
 659                         }
 660                         p = rb_next(p);
 661                 }
 662         }
 663
 664         rb_erase(&req->r_node, &mdsc->request_tree);
 665         RB_CLEAR_NODE(&req->r_node);
 666
 667         if (req->r_unsafe_dir) {
 668                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 669
 670                 spin_lock(&ci->i_unsafe_lock);
 671                 list_del_init(&req->r_unsafe_dir_item);
 672                 spin_unlock(&ci->i_unsafe_lock);
 673
 674                 iput(req->r_unsafe_dir);
 675                 req->r_unsafe_dir = NULL;
 676         }
 677
 678         complete_all(&req->r_safe_completion);
 679
 680         ceph_mdsc_put_request(req);
 681 }
 682
 683 /*
 684  * Choose mds to send request to next.  If there is a hint set in the
 685  * request (e.g., due to a prior forward hint from the mds), use that.
 686  * Otherwise, consult frag tree and/or caps to identify the
 687  * appropriate mds.  If all else fails, choose randomly.
 688  *
 689  * Called under mdsc->mutex.
 690  */
 691 static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 692 {
 693         /*
 694          * we don't need to worry about protecting the d_parent access
 695          * here because we never renaming inside the snapped namespace
 696          * except to resplice to another snapdir, and either the old or new
 697          * result is a valid result.
 698          */
 699         while (!IS_ROOT(dentry) && ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
 700                 dentry = dentry->d_parent;
 701         return dentry;
 702 }
 703
 704 static int __choose_mds(struct ceph_mds_client *mdsc,
 705                         struct ceph_mds_request *req)
 706 {
 707         struct inode *inode;
 708         struct ceph_inode_info *ci;
 709         struct ceph_cap *cap;
 710         int mode = req->r_direct_mode;
 711         int mds = -1;
 712         u32 hash = req->r_direct_hash;
 713         bool is_hash = req->r_direct_is_hash;
 714
 715         /*
 716          * is there a specific mds we should try?  ignore hint if we have
 717          * no session and the mds is not up (active or recovering).
 718          */
 719         if (req->r_resend_mds >= 0 &&
 720             (__have_session(mdsc, req->r_resend_mds) ||
 721              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 722                 dout("choose_mds using resend_mds mds%d\n",
 723                      req->r_resend_mds);
 724                 return req->r_resend_mds;
 725         }
 726
 727         if (mode == USE_RANDOM_MDS)
 728                 goto random;
 729
 730         inode = NULL;
 731         if (req->r_inode) {
 732                 inode = req->r_inode;
 733         } else if (req->r_dentry) {
 734                 /* ignore race with rename; old or new d_parent is okay */
 735                 struct dentry *parent = req->r_dentry->d_parent;
 736                 struct inode *dir = d_inode(parent);
 737
 738                 if (dir->i_sb != mdsc->fsc->sb) {
 739                         /* not this fs! */
 740                         inode = d_inode(req->r_dentry);
 741                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 742                         /* direct snapped/virtual snapdir requests
 743                          * based on parent dir inode */
 744                         struct dentry *dn = get_nonsnap_parent(parent);
 745                         inode = d_inode(dn);
 746                         dout("__choose_mds using nonsnap parent %p\n", inode);
 747                 } else {
 748                         /* dentry target */
 749                         inode = d_inode(req->r_dentry);
 750                         if (!inode || mode == USE_AUTH_MDS) {
 751                                 /* dir + name */
 752                                 inode = dir;
 753                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 754                                 is_hash = true;
 755                         }
 756                 }
 757         }
 758
 759         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 760              (int)hash, mode);
 761         if (!inode)
 762                 goto random;
 763         ci = ceph_inode(inode);
 764
 765         if (is_hash && S_ISDIR(inode->i_mode)) {
 766                 struct ceph_inode_frag frag;
 767                 int found;
 768
 769                 ceph_choose_frag(ci, hash, &frag, &found);
 770                 if (found) {
 771                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 772                                 u8 r;
 773
 774                                 /* choose a random replica */
 775                                 get_random_bytes(&r, 1);
 776                                 r %= frag.ndist;
 777                                 mds = frag.dist[r];
 778                                 dout("choose_mds %p %llx.%llx "
 779                                      "frag %u mds%d (%d/%d)\n",
 780                                      inode, ceph_vinop(inode),
 781                                      frag.frag, mds,
 782                                      (int)r, frag.ndist);
 783                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 784                                     CEPH_MDS_STATE_ACTIVE)
 785                                         return mds;
 786                         }
 787
 788                         /* since this file/dir wasn't known to be
 789                          * replicated, then we want to look for the
 790                          * authoritative mds. */
 791                         mode = USE_AUTH_MDS;
 792                         if (frag.mds >= 0) {
 793                                 /* choose auth mds */
 794                                 mds = frag.mds;
 795                                 dout("choose_mds %p %llx.%llx "
 796                                      "frag %u mds%d (auth)\n",
 797                                      inode, ceph_vinop(inode), frag.frag, mds);
 798                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 799                                     CEPH_MDS_STATE_ACTIVE)
 800                                         return mds;
 801                         }
 802                 }
 803         }
 804
 805         spin_lock(&ci->i_ceph_lock);
 806         cap = NULL;
 807         if (mode == USE_AUTH_MDS)
 808                 cap = ci->i_auth_cap;
 809         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 810                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 811         if (!cap) {
 812                 spin_unlock(&ci->i_ceph_lock);
 813                 goto random;
 814         }
 815         mds = cap->session->s_mds;
 816         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 817              inode, ceph_vinop(inode), mds,
 818              cap == ci->i_auth_cap ? "auth " : "", cap);
 819         spin_unlock(&ci->i_ceph_lock);
 820         return mds;
 821
 822 random:
 823         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 824         dout("choose_mds chose random mds%d\n", mds);
 825         return mds;
 826 }
 827
 828
 829 /*
 830  * session messages
 831  */
 832 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 833 {
 834         struct ceph_msg *msg;
 835         struct ceph_mds_session_head *h;
 836
 837         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 838                            false);
 839         if (!msg) {
 840                 pr_err("create_session_msg ENOMEM creating msg\n");
 841                 return NULL;
 842         }
 843         h = msg->front.iov_base;
 844         h->op = cpu_to_le32(op);
 845         h->seq = cpu_to_le64(seq);
 846
 847         return msg;
 848 }
 849
 850 /*
 851  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
 852  * to include additional client metadata fields.
 853  */
 854 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
 855 {
 856         struct ceph_msg *msg;
 857         struct ceph_mds_session_head *h;
 858         int i = -1;
 859         int metadata_bytes = 0;
 860         int metadata_key_count = 0;
 861         struct ceph_options *opt = mdsc->fsc->client->options;
 862         void *p;
 863
 864         const char* metadata[][2] = {
 865                 {"hostname", utsname()->nodename},
 866                 {"kernel_version", utsname()->release},
 867                 {"entity_id", opt->name ? opt->name : ""},
 868                 {NULL, NULL}
 869         };
 870
 871         /* Calculate serialized length of metadata */
 872         metadata_bytes = 4;  /* map length */
 873         for (i = 0; metadata[i][0] != NULL; ++i) {
 874                 metadata_bytes += 8 + strlen(metadata[i][0]) +
 875                         strlen(metadata[i][1]);
 876                 metadata_key_count++;
 877         }
 878
 879         /* Allocate the message */
 880         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + metadata_bytes,
 881                            GFP_NOFS, false);
 882         if (!msg) {
 883                 pr_err("create_session_msg ENOMEM creating msg\n");
 884                 return NULL;
 885         }
 886         h = msg->front.iov_base;
 887         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 888         h->seq = cpu_to_le64(seq);
 889
 890         /*
 891          * Serialize client metadata into waiting buffer space, using
 892          * the format that userspace expects for map<string, string>
 893          *
 894          * ClientSession messages with metadata are v2
 895          */
 896         msg->hdr.version = cpu_to_le16(2);
 897         msg->hdr.compat_version = cpu_to_le16(1);
 898
 899         /* The write pointer, following the session_head structure */
 900         p = msg->front.iov_base + sizeof(*h);
 901
 902         /* Number of entries in the map */
 903         ceph_encode_32(&p, metadata_key_count);
 904
 905         /* Two length-prefixed strings for each entry in the map */
 906         for (i = 0; metadata[i][0] != NULL; ++i) {
 907                 size_t const key_len = strlen(metadata[i][0]);
 908                 size_t const val_len = strlen(metadata[i][1]);
 909
 910                 ceph_encode_32(&p, key_len);
 911                 memcpy(p, metadata[i][0], key_len);
 912                 p += key_len;
 913                 ceph_encode_32(&p, val_len);
 914                 memcpy(p, metadata[i][1], val_len);
 915                 p += val_len;
 916         }
 917
 918         return msg;
 919 }
 920
 921 /*
 922  * send session open request.
 923  *
 924  * called under mdsc->mutex
 925  */
 926 static int __open_session(struct ceph_mds_client *mdsc,
 927                           struct ceph_mds_session *session)
 928 {
 929         struct ceph_msg *msg;
 930         int mstate;
 931         int mds = session->s_mds;
 932
 933         /* wait for mds to go active? */
 934         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 935         dout("open_session to mds%d (%s)\n", mds,
 936              ceph_mds_state_name(mstate));
 937         session->s_state = CEPH_MDS_SESSION_OPENING;
 938         session->s_renew_requested = jiffies;
 939
 940         /* send connect message */
 941         msg = create_session_open_msg(mdsc, session->s_seq);
 942         if (!msg)
 943                 return -ENOMEM;
 944         ceph_con_send(&session->s_con, msg);
 945         return 0;
 946 }
 947
 948 /*
 949  * open sessions for any export targets for the given mds
 950  *
 951  * called under mdsc->mutex
 952  */
 953 static struct ceph_mds_session *
 954 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
 955 {
 956         struct ceph_mds_session *session;
 957
 958         session = __ceph_lookup_mds_session(mdsc, target);
 959         if (!session) {
 960                 session = register_session(mdsc, target);
 961                 if (IS_ERR(session))
 962                         return session;
 963         }
 964         if (session->s_state == CEPH_MDS_SESSION_NEW ||
 965             session->s_state == CEPH_MDS_SESSION_CLOSING)
 966                 __open_session(mdsc, session);
 967
 968         return session;
 969 }
 970
 971 struct ceph_mds_session *
 972 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
 973 {
 974         struct ceph_mds_session *session;
 975
 976         dout("open_export_target_session to mds%d\n", target);
 977
 978         mutex_lock(&mdsc->mutex);
 979         session = __open_export_target_session(mdsc, target);
 980         mutex_unlock(&mdsc->mutex);
 981
 982         return session;
 983 }
 984
 985 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 986                                           struct ceph_mds_session *session)
 987 {
 988         struct ceph_mds_info *mi;
 989         struct ceph_mds_session *ts;
 990         int i, mds = session->s_mds;
 991
 992         if (mds >= mdsc->mdsmap->m_max_mds)
 993                 return;
 994
 995         mi = &mdsc->mdsmap->m_info[mds];
 996         dout("open_export_target_sessions for mds%d (%d targets)\n",
 997              session->s_mds, mi->num_export_targets);
 998
 999         for (i = 0; i < mi->num_export_targets; i++) {
1000                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1001                 if (!IS_ERR(ts))
1002                         ceph_put_mds_session(ts);
1003         }
1004 }
1005
1006 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1007                                            struct ceph_mds_session *session)
1008 {
1009         mutex_lock(&mdsc->mutex);
1010         __open_export_target_sessions(mdsc, session);
1011         mutex_unlock(&mdsc->mutex);
1012 }
1013
1014 /*
1015  * session caps
1016  */
1017
1018 /* caller holds s_cap_lock, we drop it */
1019 static void cleanup_cap_releases(struct ceph_mds_client *mdsc,
1020                                  struct ceph_mds_session *session)
1021         __releases(session->s_cap_lock)
1022 {
1023         LIST_HEAD(tmp_list);
1024         list_splice_init(&session->s_cap_releases, &tmp_list);
1025         session->s_num_cap_releases = 0;
1026         spin_unlock(&session->s_cap_lock);
1027
1028         dout("cleanup_cap_releases mds%d\n", session->s_mds);
1029         while (!list_empty(&tmp_list)) {
1030                 struct ceph_cap *cap;
1031                 /* zero out the in-progress message */
1032                 cap = list_first_entry(&tmp_list,
1033                                         struct ceph_cap, session_caps);
1034                 list_del(&cap->session_caps);
1035                 ceph_put_cap(mdsc, cap);
1036         }
1037 }
1038
1039 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1040                                      struct ceph_mds_session *session)
1041 {
1042         struct ceph_mds_request *req;
1043         struct rb_node *p;
1044
1045         dout("cleanup_session_requests mds%d\n", session->s_mds);
1046         mutex_lock(&mdsc->mutex);
1047         while (!list_empty(&session->s_unsafe)) {
1048                 req = list_first_entry(&session->s_unsafe,
1049                                        struct ceph_mds_request, r_unsafe_item);
1050                 list_del_init(&req->r_unsafe_item);
1051                 pr_info(" dropping unsafe request %llu\n", req->r_tid);
1052                 __unregister_request(mdsc, req);
1053         }
1054         /* zero r_attempts, so kick_requests() will re-send requests */
1055         p = rb_first(&mdsc->request_tree);
1056         while (p) {
1057                 req = rb_entry(p, struct ceph_mds_request, r_node);
1058                 p = rb_next(p);
1059                 if (req->r_session &&
1060                     req->r_session->s_mds == session->s_mds)
1061                         req->r_attempts = 0;
1062         }
1063         mutex_unlock(&mdsc->mutex);
1064 }
1065
1066 /*
1067  * Helper to safely iterate over all caps associated with a session, with
1068  * special care taken to handle a racing __ceph_remove_cap().
1069  *
1070  * Caller must hold session s_mutex.
1071  */
1072 static int iterate_session_caps(struct ceph_mds_session *session,
1073                                  int (*cb)(struct inode *, struct ceph_cap *,
1074                                             void *), void *arg)
1075 {
1076         struct list_head *p;
1077         struct ceph_cap *cap;
1078         struct inode *inode, *last_inode = NULL;
1079         struct ceph_cap *old_cap = NULL;
1080         int ret;
1081
1082         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1083         spin_lock(&session->s_cap_lock);
1084         p = session->s_caps.next;
1085         while (p != &session->s_caps) {
1086                 cap = list_entry(p, struct ceph_cap, session_caps);
1087                 inode = igrab(&cap->ci->vfs_inode);
1088                 if (!inode) {
1089                         p = p->next;
1090                         continue;
1091                 }
1092                 session->s_cap_iterator = cap;
1093                 spin_unlock(&session->s_cap_lock);
1094
1095                 if (last_inode) {
1096                         iput(last_inode);
1097                         last_inode = NULL;
1098                 }
1099                 if (old_cap) {
1100                         ceph_put_cap(session->s_mdsc, old_cap);
1101                         old_cap = NULL;
1102                 }
1103
1104                 ret = cb(inode, cap, arg);
1105                 last_inode = inode;
1106
1107                 spin_lock(&session->s_cap_lock);
1108                 p = p->next;
1109                 if (cap->ci == NULL) {
1110                         dout("iterate_session_caps  finishing cap %p removal\n",
1111                              cap);
1112                         BUG_ON(cap->session != session);
1113                         cap->session = NULL;
1114                         list_del_init(&cap->session_caps);
1115                         session->s_nr_caps--;
1116                         if (cap->queue_release) {
1117                                 list_add_tail(&cap->session_caps,
1118                                               &session->s_cap_releases);
1119                                 session->s_num_cap_releases++;
1120                         } else {
1121                                 old_cap = cap;  /* put_cap it w/o locks held */
1122                         }
1123                 }
1124                 if (ret < 0)
1125                         goto out;
1126         }
1127         ret = 0;
1128 out:
1129         session->s_cap_iterator = NULL;
1130         spin_unlock(&session->s_cap_lock);
1131
1132         iput(last_inode);
1133         if (old_cap)
1134                 ceph_put_cap(session->s_mdsc, old_cap);
1135
1136         return ret;
1137 }
1138
1139 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1140                                   void *arg)
1141 {
1142         struct ceph_inode_info *ci = ceph_inode(inode);
1143         int drop = 0;
1144
1145         dout("removing cap %p, ci is %p, inode is %p\n",
1146              cap, ci, &ci->vfs_inode);
1147         spin_lock(&ci->i_ceph_lock);
1148         __ceph_remove_cap(cap, false);
1149         if (!ci->i_auth_cap) {
1150                 struct ceph_mds_client *mdsc =
1151                         ceph_sb_to_client(inode->i_sb)->mdsc;
1152
1153                 spin_lock(&mdsc->cap_dirty_lock);
1154                 if (!list_empty(&ci->i_dirty_item)) {
1155                         pr_info(" dropping dirty %s state for %p %lld\n",
1156                                 ceph_cap_string(ci->i_dirty_caps),
1157                                 inode, ceph_ino(inode));
1158                         ci->i_dirty_caps = 0;
1159                         list_del_init(&ci->i_dirty_item);
1160                         drop = 1;
1161                 }
1162                 if (!list_empty(&ci->i_flushing_item)) {
1163                         pr_info(" dropping dirty+flushing %s state for %p %lld\n",
1164                                 ceph_cap_string(ci->i_flushing_caps),
1165                                 inode, ceph_ino(inode));
1166                         ci->i_flushing_caps = 0;
1167                         list_del_init(&ci->i_flushing_item);
1168                         mdsc->num_cap_flushing--;
1169                         drop = 1;
1170                 }
1171                 spin_unlock(&mdsc->cap_dirty_lock);
1172         }
1173         spin_unlock(&ci->i_ceph_lock);
1174         while (drop--)
1175                 iput(inode);
1176         return 0;
1177 }
1178
1179 /*
1180  * caller must hold session s_mutex
1181  */
1182 static void remove_session_caps(struct ceph_mds_session *session)
1183 {
1184         dout("remove_session_caps on %p\n", session);
1185         iterate_session_caps(session, remove_session_caps_cb, NULL);
1186
1187         spin_lock(&session->s_cap_lock);
1188         if (session->s_nr_caps > 0) {
1189                 struct super_block *sb = session->s_mdsc->fsc->sb;
1190                 struct inode *inode;
1191                 struct ceph_cap *cap, *prev = NULL;
1192                 struct ceph_vino vino;
1193                 /*
1194                  * iterate_session_caps() skips inodes that are being
1195                  * deleted, we need to wait until deletions are complete.
1196                  * __wait_on_freeing_inode() is designed for the job,
1197                  * but it is not exported, so use lookup inode function
1198                  * to access it.
1199                  */
1200                 while (!list_empty(&session->s_caps)) {
1201                         cap = list_entry(session->s_caps.next,
1202                                          struct ceph_cap, session_caps);
1203                         if (cap == prev)
1204                                 break;
1205                         prev = cap;
1206                         vino = cap->ci->i_vino;
1207                         spin_unlock(&session->s_cap_lock);
1208
1209                         inode = ceph_find_inode(sb, vino);
1210                         iput(inode);
1211
1212                         spin_lock(&session->s_cap_lock);
1213                 }
1214         }
1215
1216         // drop cap expires and unlock s_cap_lock
1217         cleanup_cap_releases(session->s_mdsc, session);
1218
1219         BUG_ON(session->s_nr_caps > 0);
1220         BUG_ON(!list_empty(&session->s_cap_flushing));
1221 }
1222
1223 /*
1224  * wake up any threads waiting on this session's caps.  if the cap is
1225  * old (didn't get renewed on the client reconnect), remove it now.
1226  *
1227  * caller must hold s_mutex.
1228  */
1229 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1230                               void *arg)
1231 {
1232         struct ceph_inode_info *ci = ceph_inode(inode);
1233
1234         wake_up_all(&ci->i_cap_wq);
1235         if (arg) {
1236                 spin_lock(&ci->i_ceph_lock);
1237                 ci->i_wanted_max_size = 0;
1238                 ci->i_requested_max_size = 0;
1239                 spin_unlock(&ci->i_ceph_lock);
1240         }
1241         return 0;
1242 }
1243
1244 static void wake_up_session_caps(struct ceph_mds_session *session,
1245                                  int reconnect)
1246 {
1247         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1248         iterate_session_caps(session, wake_up_session_cb,
1249                              (void *)(unsigned long)reconnect);
1250 }
1251
1252 /*
1253  * Send periodic message to MDS renewing all currently held caps.  The
1254  * ack will reset the expiration for all caps from this session.
1255  *
1256  * caller holds s_mutex
1257  */
1258 static int send_renew_caps(struct ceph_mds_client *mdsc,
1259                            struct ceph_mds_session *session)
1260 {
1261         struct ceph_msg *msg;
1262         int state;
1263
1264         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1265             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1266                 pr_info("mds%d caps stale\n", session->s_mds);
1267         session->s_renew_requested = jiffies;
1268
1269         /* do not try to renew caps until a recovering mds has reconnected
1270          * with its clients. */
1271         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1272         if (state < CEPH_MDS_STATE_RECONNECT) {
1273                 dout("send_renew_caps ignoring mds%d (%s)\n",
1274                      session->s_mds, ceph_mds_state_name(state));
1275                 return 0;
1276         }
1277
1278         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1279                 ceph_mds_state_name(state));
1280         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1281                                  ++session->s_renew_seq);
1282         if (!msg)
1283                 return -ENOMEM;
1284         ceph_con_send(&session->s_con, msg);
1285         return 0;
1286 }
1287
1288 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1289                              struct ceph_mds_session *session, u64 seq)
1290 {
1291         struct ceph_msg *msg;
1292
1293         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1294              session->s_mds, ceph_session_state_name(session->s_state), seq);
1295         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1296         if (!msg)
1297                 return -ENOMEM;
1298         ceph_con_send(&session->s_con, msg);
1299         return 0;
1300 }
1301
1302
1303 /*
1304  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1305  *
1306  * Called under session->s_mutex
1307  */
1308 static void renewed_caps(struct ceph_mds_client *mdsc,
1309                          struct ceph_mds_session *session, int is_renew)
1310 {
1311         int was_stale;
1312         int wake = 0;
1313
1314         spin_lock(&session->s_cap_lock);
1315         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1316
1317         session->s_cap_ttl = session->s_renew_requested +
1318                 mdsc->mdsmap->m_session_timeout*HZ;
1319
1320         if (was_stale) {
1321                 if (time_before(jiffies, session->s_cap_ttl)) {
1322                         pr_info("mds%d caps renewed\n", session->s_mds);
1323                         wake = 1;
1324                 } else {
1325                         pr_info("mds%d caps still stale\n", session->s_mds);
1326                 }
1327         }
1328         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1329              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1330              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1331         spin_unlock(&session->s_cap_lock);
1332
1333         if (wake)
1334                 wake_up_session_caps(session, 0);
1335 }
1336
1337 /*
1338  * send a session close request
1339  */
1340 static int request_close_session(struct ceph_mds_client *mdsc,
1341                                  struct ceph_mds_session *session)
1342 {
1343         struct ceph_msg *msg;
1344
1345         dout("request_close_session mds%d state %s seq %lld\n",
1346              session->s_mds, ceph_session_state_name(session->s_state),
1347              session->s_seq);
1348         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1349         if (!msg)
1350                 return -ENOMEM;
1351         ceph_con_send(&session->s_con, msg);
1352         return 0;
1353 }
1354
1355 /*
1356  * Called with s_mutex held.
1357  */
1358 static int __close_session(struct ceph_mds_client *mdsc,
1359                          struct ceph_mds_session *session)
1360 {
1361         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1362                 return 0;
1363         session->s_state = CEPH_MDS_SESSION_CLOSING;
1364         return request_close_session(mdsc, session);
1365 }
1366
1367 /*
1368  * Trim old(er) caps.
1369  *
1370  * Because we can't cache an inode without one or more caps, we do
1371  * this indirectly: if a cap is unused, we prune its aliases, at which
1372  * point the inode will hopefully get dropped to.
1373  *
1374  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1375  * memory pressure from the MDS, though, so it needn't be perfect.
1376  */
1377 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1378 {
1379         struct ceph_mds_session *session = arg;
1380         struct ceph_inode_info *ci = ceph_inode(inode);
1381         int used, wanted, oissued, mine;
1382
1383         if (session->s_trim_caps <= 0)
1384                 return -1;
1385
1386         spin_lock(&ci->i_ceph_lock);
1387         mine = cap->issued | cap->implemented;
1388         used = __ceph_caps_used(ci);
1389         wanted = __ceph_caps_file_wanted(ci);
1390         oissued = __ceph_caps_issued_other(ci, cap);
1391
1392         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1393              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1394              ceph_cap_string(used), ceph_cap_string(wanted));
1395         if (cap == ci->i_auth_cap) {
1396                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1397                     !list_empty(&ci->i_cap_snaps))
1398                         goto out;
1399                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1400                         goto out;
1401         }
1402         if ((used | wanted) & ~oissued & mine)
1403                 goto out;   /* we need these caps */
1404
1405         session->s_trim_caps--;
1406         if (oissued) {
1407                 /* we aren't the only cap.. just remove us */
1408                 __ceph_remove_cap(cap, true);
1409         } else {
1410                 /* try to drop referring dentries */
1411                 spin_unlock(&ci->i_ceph_lock);
1412                 d_prune_aliases(inode);
1413                 dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1414                      inode, cap, atomic_read(&inode->i_count));
1415                 return 0;
1416         }
1417
1418 out:
1419         spin_unlock(&ci->i_ceph_lock);
1420         return 0;
1421 }
1422
1423 /*
1424  * Trim session cap count down to some max number.
1425  */
1426 static int trim_caps(struct ceph_mds_client *mdsc,
1427                      struct ceph_mds_session *session,
1428                      int max_caps)
1429 {
1430         int trim_caps = session->s_nr_caps - max_caps;
1431
1432         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1433              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1434         if (trim_caps > 0) {
1435                 session->s_trim_caps = trim_caps;
1436                 iterate_session_caps(session, trim_caps_cb, session);
1437                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1438                      session->s_mds, session->s_nr_caps, max_caps,
1439                         trim_caps - session->s_trim_caps);
1440                 session->s_trim_caps = 0;
1441         }
1442
1443         ceph_send_cap_releases(mdsc, session);
1444         return 0;
1445 }
1446
1447 static int check_cap_flush(struct ceph_inode_info *ci,
1448                            u64 want_flush_seq, u64 want_snap_seq)
1449 {
1450         int ret1 = 1, ret2 = 1;
1451         spin_lock(&ci->i_ceph_lock);
1452         if (want_flush_seq > 0 && ci->i_flushing_caps)
1453                 ret1 = ci->i_cap_flush_seq >= want_flush_seq;
1454
1455         if (want_snap_seq > 0 && !list_empty(&ci->i_cap_snaps)) {
1456                 struct ceph_cap_snap *capsnap =
1457                         list_first_entry(&ci->i_cap_snaps,
1458                                          struct ceph_cap_snap, ci_item);
1459                 ret2 = capsnap->follows >= want_snap_seq;
1460         }
1461         spin_unlock(&ci->i_ceph_lock);
1462         return ret1 && ret2;
1463 }
1464
1465 /*
1466  * flush all dirty inode data to disk.
1467  *
1468  * returns true if we've flushed through want_flush_seq
1469  */
1470 static void wait_caps_flush(struct ceph_mds_client *mdsc,
1471                             u64 want_flush_seq, u64 want_snap_seq)
1472 {
1473         int mds;
1474
1475         dout("check_cap_flush want %lld\n", want_flush_seq);
1476         mutex_lock(&mdsc->mutex);
1477         for (mds = 0; mds < mdsc->max_sessions; ) {
1478                 struct ceph_mds_session *session = mdsc->sessions[mds];
1479                 struct inode *inode1 = NULL, *inode2 = NULL;
1480
1481                 if (!session) {
1482                         mds++;
1483                         continue;
1484                 }
1485                 get_session(session);
1486                 mutex_unlock(&mdsc->mutex);
1487
1488                 mutex_lock(&session->s_mutex);
1489                 if (!list_empty(&session->s_cap_flushing)) {
1490                         struct ceph_inode_info *ci =
1491                                 list_first_entry(&session->s_cap_flushing,
1492                                                  struct ceph_inode_info,
1493                                                  i_flushing_item);
1494
1495                         if (!check_cap_flush(ci, want_flush_seq, 0)) {
1496                                 dout("check_cap_flush still flushing %p "
1497                                      "seq %lld <= %lld to mds%d\n",
1498                                      &ci->vfs_inode, ci->i_cap_flush_seq,
1499                                      want_flush_seq, mds);
1500                                 inode1 = igrab(&ci->vfs_inode);
1501                         }
1502                 }
1503                 if (!list_empty(&session->s_cap_snaps_flushing)) {
1504                         struct ceph_cap_snap *capsnap =
1505                                 list_first_entry(&session->s_cap_snaps_flushing,
1506                                                  struct ceph_cap_snap,
1507                                                  flushing_item);
1508                         struct ceph_inode_info *ci = capsnap->ci;
1509                         if (!check_cap_flush(ci, 0, want_snap_seq)) {
1510                                 dout("check_cap_flush still flushing snap %p "
1511                                      "follows %lld <= %lld to mds%d\n",
1512                                      &ci->vfs_inode, capsnap->follows,
1513                                      want_snap_seq, mds);
1514                                 inode2 = igrab(&ci->vfs_inode);
1515                         }
1516                 }
1517                 mutex_unlock(&session->s_mutex);
1518                 ceph_put_mds_session(session);
1519
1520                 if (inode1) {
1521                         wait_event(mdsc->cap_flushing_wq,
1522                                    check_cap_flush(ceph_inode(inode1),
1523                                                    want_flush_seq, 0));
1524                         iput(inode1);
1525                 }
1526                 if (inode2) {
1527                         wait_event(mdsc->cap_flushing_wq,
1528                                    check_cap_flush(ceph_inode(inode2),
1529                                                    0, want_snap_seq));
1530                         iput(inode2);
1531                 }
1532
1533                 if (!inode1 && !inode2)
1534                         mds++;
1535
1536                 mutex_lock(&mdsc->mutex);
1537         }
1538
1539         mutex_unlock(&mdsc->mutex);
1540         dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq);
1541 }
1542
1543 /*
1544  * called under s_mutex
1545  */
1546 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1547                             struct ceph_mds_session *session)
1548 {
1549         struct ceph_msg *msg = NULL;
1550         struct ceph_mds_cap_release *head;
1551         struct ceph_mds_cap_item *item;
1552         struct ceph_cap *cap;
1553         LIST_HEAD(tmp_list);
1554         int num_cap_releases;
1555
1556         spin_lock(&session->s_cap_lock);
1557 again:
1558         list_splice_init(&session->s_cap_releases, &tmp_list);
1559         num_cap_releases = session->s_num_cap_releases;
1560         session->s_num_cap_releases = 0;
1561         spin_unlock(&session->s_cap_lock);
1562
1563         while (!list_empty(&tmp_list)) {
1564                 if (!msg) {
1565                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1566                                         PAGE_CACHE_SIZE, GFP_NOFS, false);
1567                         if (!msg)
1568                                 goto out_err;
1569                         head = msg->front.iov_base;
1570                         head->num = cpu_to_le32(0);
1571                         msg->front.iov_len = sizeof(*head);
1572                 }
1573                 cap = list_first_entry(&tmp_list, struct ceph_cap,
1574                                         session_caps);
1575                 list_del(&cap->session_caps);
1576                 num_cap_releases--;
1577
1578                 head = msg->front.iov_base;
1579                 le32_add_cpu(&head->num, 1);
1580                 item = msg->front.iov_base + msg->front.iov_len;
1581                 item->ino = cpu_to_le64(cap->cap_ino);
1582                 item->cap_id = cpu_to_le64(cap->cap_id);
1583                 item->migrate_seq = cpu_to_le32(cap->mseq);
1584                 item->seq = cpu_to_le32(cap->issue_seq);
1585                 msg->front.iov_len += sizeof(*item);
1586
1587                 ceph_put_cap(mdsc, cap);
1588
1589                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1590                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1591                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1592                         ceph_con_send(&session->s_con, msg);
1593                         msg = NULL;
1594                 }
1595         }
1596
1597         BUG_ON(num_cap_releases != 0);
1598
1599         spin_lock(&session->s_cap_lock);
1600         if (!list_empty(&session->s_cap_releases))
1601                 goto again;
1602         spin_unlock(&session->s_cap_lock);
1603
1604         if (msg) {
1605                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1606                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1607                 ceph_con_send(&session->s_con, msg);
1608         }
1609         return;
1610 out_err:
1611         pr_err("send_cap_releases mds%d, failed to allocate message\n",
1612                 session->s_mds);
1613         spin_lock(&session->s_cap_lock);
1614         list_splice(&tmp_list, &session->s_cap_releases);
1615         session->s_num_cap_releases += num_cap_releases;
1616         spin_unlock(&session->s_cap_lock);
1617 }
1618
1619 /*
1620  * requests
1621  */
1622
1623 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1624                                     struct inode *dir)
1625 {
1626         struct ceph_inode_info *ci = ceph_inode(dir);
1627         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1628         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1629         size_t size = sizeof(*rinfo->dir_in) + sizeof(*rinfo->dir_dname_len) +
1630                       sizeof(*rinfo->dir_dname) + sizeof(*rinfo->dir_dlease);
1631         int order, num_entries;
1632
1633         spin_lock(&ci->i_ceph_lock);
1634         num_entries = ci->i_files + ci->i_subdirs;
1635         spin_unlock(&ci->i_ceph_lock);
1636         num_entries = max(num_entries, 1);
1637         num_entries = min(num_entries, opt->max_readdir);
1638
1639         order = get_order(size * num_entries);
1640         while (order >= 0) {
1641                 rinfo->dir_in = (void*)__get_free_pages(GFP_NOFS | __GFP_NOWARN,
1642                                                         order);
1643                 if (rinfo->dir_in)
1644                         break;
1645                 order--;
1646         }
1647         if (!rinfo->dir_in)
1648                 return -ENOMEM;
1649
1650         num_entries = (PAGE_SIZE << order) / size;
1651         num_entries = min(num_entries, opt->max_readdir);
1652
1653         rinfo->dir_buf_size = PAGE_SIZE << order;
1654         req->r_num_caps = num_entries + 1;
1655         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1656         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1657         return 0;
1658 }
1659
1660 /*
1661  * Create an mds request.
1662  */
1663 struct ceph_mds_request *
1664 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1665 {
1666         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1667
1668         if (!req)
1669                 return ERR_PTR(-ENOMEM);
1670
1671         mutex_init(&req->r_fill_mutex);
1672         req->r_mdsc = mdsc;
1673         req->r_started = jiffies;
1674         req->r_resend_mds = -1;
1675         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1676         req->r_fmode = -1;
1677         kref_init(&req->r_kref);
1678         INIT_LIST_HEAD(&req->r_wait);
1679         init_completion(&req->r_completion);
1680         init_completion(&req->r_safe_completion);
1681         INIT_LIST_HEAD(&req->r_unsafe_item);
1682
1683         req->r_stamp = CURRENT_TIME;
1684
1685         req->r_op = op;
1686         req->r_direct_mode = mode;
1687         return req;
1688 }
1689
1690 /*
1691  * return oldest (lowest) request, tid in request tree, 0 if none.
1692  *
1693  * called under mdsc->mutex.
1694  */
1695 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1696 {
1697         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1698                 return NULL;
1699         return rb_entry(rb_first(&mdsc->request_tree),
1700                         struct ceph_mds_request, r_node);
1701 }
1702
1703 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1704 {
1705         return mdsc->oldest_tid;
1706 }
1707
1708 /*
1709  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1710  * on build_path_from_dentry in fs/cifs/dir.c.
1711  *
1712  * If @stop_on_nosnap, generate path relative to the first non-snapped
1713  * inode.
1714  *
1715  * Encode hidden .snap dirs as a double /, i.e.
1716  *   foo/.snap/bar -> foo//bar
1717  */
1718 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1719                            int stop_on_nosnap)
1720 {
1721         struct dentry *temp;
1722         char *path;
1723         int len, pos;
1724         unsigned seq;
1725
1726         if (dentry == NULL)
1727                 return ERR_PTR(-EINVAL);
1728
1729 retry:
1730         len = 0;
1731         seq = read_seqbegin(&rename_lock);
1732         rcu_read_lock();
1733         for (temp = dentry; !IS_ROOT(temp);) {
1734                 struct inode *inode = d_inode(temp);
1735                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1736                         len++;  /* slash only */
1737                 else if (stop_on_nosnap && inode &&
1738                          ceph_snap(inode) == CEPH_NOSNAP)
1739                         break;
1740                 else
1741                         len += 1 + temp->d_name.len;
1742                 temp = temp->d_parent;
1743         }
1744         rcu_read_unlock();
1745         if (len)
1746                 len--;  /* no leading '/' */
1747
1748         path = kmalloc(len+1, GFP_NOFS);
1749         if (path == NULL)
1750                 return ERR_PTR(-ENOMEM);
1751         pos = len;
1752         path[pos] = 0;  /* trailing null */
1753         rcu_read_lock();
1754         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1755                 struct inode *inode;
1756
1757                 spin_lock(&temp->d_lock);
1758                 inode = d_inode(temp);
1759                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1760                         dout("build_path path+%d: %p SNAPDIR\n",
1761                              pos, temp);
1762                 } else if (stop_on_nosnap && inode &&
1763                            ceph_snap(inode) == CEPH_NOSNAP) {
1764                         spin_unlock(&temp->d_lock);
1765                         break;
1766                 } else {
1767                         pos -= temp->d_name.len;
1768                         if (pos < 0) {
1769                                 spin_unlock(&temp->d_lock);
1770                                 break;
1771                         }
1772                         strncpy(path + pos, temp->d_name.name,
1773                                 temp->d_name.len);
1774                 }
1775                 spin_unlock(&temp->d_lock);
1776                 if (pos)
1777                         path[--pos] = '/';
1778                 temp = temp->d_parent;
1779         }
1780         rcu_read_unlock();
1781         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1782                 pr_err("build_path did not end path lookup where "
1783                        "expected, namelen is %d, pos is %d\n", len, pos);
1784                 /* presumably this is only possible if racing with a
1785                    rename of one of the parent directories (we can not
1786                    lock the dentries above us to prevent this, but
1787                    retrying should be harmless) */
1788                 kfree(path);
1789                 goto retry;
1790         }
1791
1792         *base = ceph_ino(d_inode(temp));
1793         *plen = len;
1794         dout("build_path on %p %d built %llx '%.*s'\n",
1795              dentry, d_count(dentry), *base, len, path);
1796         return path;
1797 }
1798
1799 static int build_dentry_path(struct dentry *dentry,
1800                              const char **ppath, int *ppathlen, u64 *pino,
1801                              int *pfreepath)
1802 {
1803         char *path;
1804
1805         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP) {
1806                 *pino = ceph_ino(d_inode(dentry->d_parent));
1807                 *ppath = dentry->d_name.name;
1808                 *ppathlen = dentry->d_name.len;
1809                 return 0;
1810         }
1811         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1812         if (IS_ERR(path))
1813                 return PTR_ERR(path);
1814         *ppath = path;
1815         *pfreepath = 1;
1816         return 0;
1817 }
1818
1819 static int build_inode_path(struct inode *inode,
1820                             const char **ppath, int *ppathlen, u64 *pino,
1821                             int *pfreepath)
1822 {
1823         struct dentry *dentry;
1824         char *path;
1825
1826         if (ceph_snap(inode) == CEPH_NOSNAP) {
1827                 *pino = ceph_ino(inode);
1828                 *ppathlen = 0;
1829                 return 0;
1830         }
1831         dentry = d_find_alias(inode);
1832         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1833         dput(dentry);
1834         if (IS_ERR(path))
1835                 return PTR_ERR(path);
1836         *ppath = path;
1837         *pfreepath = 1;
1838         return 0;
1839 }
1840
1841 /*
1842  * request arguments may be specified via an inode *, a dentry *, or
1843  * an explicit ino+path.
1844  */
1845 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1846                                   const char *rpath, u64 rino,
1847                                   const char **ppath, int *pathlen,
1848                                   u64 *ino, int *freepath)
1849 {
1850         int r = 0;
1851
1852         if (rinode) {
1853                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1854                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1855                      ceph_snap(rinode));
1856         } else if (rdentry) {
1857                 r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1858                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1859                      *ppath);
1860         } else if (rpath || rino) {
1861                 *ino = rino;
1862                 *ppath = rpath;
1863                 *pathlen = rpath ? strlen(rpath) : 0;
1864                 dout(" path %.*s\n", *pathlen, rpath);
1865         }
1866
1867         return r;
1868 }
1869
1870 /*
1871  * called under mdsc->mutex
1872  */
1873 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1874                                                struct ceph_mds_request *req,
1875                                                int mds, bool drop_cap_releases)
1876 {
1877         struct ceph_msg *msg;
1878         struct ceph_mds_request_head *head;
1879         const char *path1 = NULL;
1880         const char *path2 = NULL;
1881         u64 ino1 = 0, ino2 = 0;
1882         int pathlen1 = 0, pathlen2 = 0;
1883         int freepath1 = 0, freepath2 = 0;
1884         int len;
1885         u16 releases;
1886         void *p, *end;
1887         int ret;
1888
1889         ret = set_request_path_attr(req->r_inode, req->r_dentry,
1890                               req->r_path1, req->r_ino1.ino,
1891                               &path1, &pathlen1, &ino1, &freepath1);
1892         if (ret < 0) {
1893                 msg = ERR_PTR(ret);
1894                 goto out;
1895         }
1896
1897         ret = set_request_path_attr(NULL, req->r_old_dentry,
1898                               req->r_path2, req->r_ino2.ino,
1899                               &path2, &pathlen2, &ino2, &freepath2);
1900         if (ret < 0) {
1901                 msg = ERR_PTR(ret);
1902                 goto out_free1;
1903         }
1904
1905         len = sizeof(*head) +
1906                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1907                 sizeof(struct timespec);
1908
1909         /* calculate (max) length for cap releases */
1910         len += sizeof(struct ceph_mds_request_release) *
1911                 (!!req->r_inode_drop + !!req->r_dentry_drop +
1912                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1913         if (req->r_dentry_drop)
1914                 len += req->r_dentry->d_name.len;
1915         if (req->r_old_dentry_drop)
1916                 len += req->r_old_dentry->d_name.len;
1917
1918         msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1919         if (!msg) {
1920                 msg = ERR_PTR(-ENOMEM);
1921                 goto out_free2;
1922         }
1923
1924         msg->hdr.version = cpu_to_le16(2);
1925         msg->hdr.tid = cpu_to_le64(req->r_tid);
1926
1927         head = msg->front.iov_base;
1928         p = msg->front.iov_base + sizeof(*head);
1929         end = msg->front.iov_base + msg->front.iov_len;
1930
1931         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1932         head->op = cpu_to_le32(req->r_op);
1933         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1934         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1935         head->args = req->r_args;
1936
1937         ceph_encode_filepath(&p, end, ino1, path1);
1938         ceph_encode_filepath(&p, end, ino2, path2);
1939
1940         /* make note of release offset, in case we need to replay */
1941         req->r_request_release_offset = p - msg->front.iov_base;
1942
1943         /* cap releases */
1944         releases = 0;
1945         if (req->r_inode_drop)
1946                 releases += ceph_encode_inode_release(&p,
1947                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
1948                       mds, req->r_inode_drop, req->r_inode_unless, 0);
1949         if (req->r_dentry_drop)
1950                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
1951                        mds, req->r_dentry_drop, req->r_dentry_unless);
1952         if (req->r_old_dentry_drop)
1953                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1954                        mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1955         if (req->r_old_inode_drop)
1956                 releases += ceph_encode_inode_release(&p,
1957                       d_inode(req->r_old_dentry),
1958                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1959
1960         if (drop_cap_releases) {
1961                 releases = 0;
1962                 p = msg->front.iov_base + req->r_request_release_offset;
1963         }
1964
1965         head->num_releases = cpu_to_le16(releases);
1966
1967         /* time stamp */
1968         {
1969                 struct ceph_timespec ts;
1970                 ceph_encode_timespec(&ts, &req->r_stamp);
1971                 ceph_encode_copy(&p, &ts, sizeof(ts));
1972         }
1973
1974         BUG_ON(p > end);
1975         msg->front.iov_len = p - msg->front.iov_base;
1976         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1977
1978         if (req->r_pagelist) {
1979                 struct ceph_pagelist *pagelist = req->r_pagelist;
1980                 atomic_inc(&pagelist->refcnt);
1981                 ceph_msg_data_add_pagelist(msg, pagelist);
1982                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
1983         } else {
1984                 msg->hdr.data_len = 0;
1985         }
1986
1987         msg->hdr.data_off = cpu_to_le16(0);
1988
1989 out_free2:
1990         if (freepath2)
1991                 kfree((char *)path2);
1992 out_free1:
1993         if (freepath1)
1994                 kfree((char *)path1);
1995 out:
1996         return msg;
1997 }
1998
1999 /*
2000  * called under mdsc->mutex if error, under no mutex if
2001  * success.
2002  */
2003 static void complete_request(struct ceph_mds_client *mdsc,
2004                              struct ceph_mds_request *req)
2005 {
2006         if (req->r_callback)
2007                 req->r_callback(mdsc, req);
2008         else
2009                 complete_all(&req->r_completion);
2010 }
2011
2012 /*
2013  * called under mdsc->mutex
2014  */
2015 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2016                                   struct ceph_mds_request *req,
2017                                   int mds, bool drop_cap_releases)
2018 {
2019         struct ceph_mds_request_head *rhead;
2020         struct ceph_msg *msg;
2021         int flags = 0;
2022
2023         req->r_attempts++;
2024         if (req->r_inode) {
2025                 struct ceph_cap *cap =
2026                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2027
2028                 if (cap)
2029                         req->r_sent_on_mseq = cap->mseq;
2030                 else
2031                         req->r_sent_on_mseq = -1;
2032         }
2033         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2034              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2035
2036         if (req->r_got_unsafe) {
2037                 void *p;
2038                 /*
2039                  * Replay.  Do not regenerate message (and rebuild
2040                  * paths, etc.); just use the original message.
2041                  * Rebuilding paths will break for renames because
2042                  * d_move mangles the src name.
2043                  */
2044                 msg = req->r_request;
2045                 rhead = msg->front.iov_base;
2046
2047                 flags = le32_to_cpu(rhead->flags);
2048                 flags |= CEPH_MDS_FLAG_REPLAY;
2049                 rhead->flags = cpu_to_le32(flags);
2050
2051                 if (req->r_target_inode)
2052                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2053
2054                 rhead->num_retry = req->r_attempts - 1;
2055
2056                 /* remove cap/dentry releases from message */
2057                 rhead->num_releases = 0;
2058
2059                 /* time stamp */
2060                 p = msg->front.iov_base + req->r_request_release_offset;
2061                 {
2062                         struct ceph_timespec ts;
2063                         ceph_encode_timespec(&ts, &req->r_stamp);
2064                         ceph_encode_copy(&p, &ts, sizeof(ts));
2065                 }
2066
2067                 msg->front.iov_len = p - msg->front.iov_base;
2068                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2069                 return 0;
2070         }
2071
2072         if (req->r_request) {
2073                 ceph_msg_put(req->r_request);
2074                 req->r_request = NULL;
2075         }
2076         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2077         if (IS_ERR(msg)) {
2078                 req->r_err = PTR_ERR(msg);
2079                 complete_request(mdsc, req);
2080                 return PTR_ERR(msg);
2081         }
2082         req->r_request = msg;
2083
2084         rhead = msg->front.iov_base;
2085         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2086         if (req->r_got_unsafe)
2087                 flags |= CEPH_MDS_FLAG_REPLAY;
2088         if (req->r_locked_dir)
2089                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2090         rhead->flags = cpu_to_le32(flags);
2091         rhead->num_fwd = req->r_num_fwd;
2092         rhead->num_retry = req->r_attempts - 1;
2093         rhead->ino = 0;
2094
2095         dout(" r_locked_dir = %p\n", req->r_locked_dir);
2096         return 0;
2097 }
2098
2099 /*
2100  * send request, or put it on the appropriate wait list.
2101  */
2102 static int __do_request(struct ceph_mds_client *mdsc,
2103                         struct ceph_mds_request *req)
2104 {
2105         struct ceph_mds_session *session = NULL;
2106         int mds = -1;
2107         int err = -EAGAIN;
2108
2109         if (req->r_err || req->r_got_result) {
2110                 if (req->r_aborted)
2111                         __unregister_request(mdsc, req);
2112                 goto out;
2113         }
2114
2115         if (req->r_timeout &&
2116             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2117                 dout("do_request timed out\n");
2118                 err = -EIO;
2119                 goto finish;
2120         }
2121
2122         put_request_session(req);
2123
2124         mds = __choose_mds(mdsc, req);
2125         if (mds < 0 ||
2126             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2127                 dout("do_request no mds or not active, waiting for map\n");
2128                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2129                 goto out;
2130         }
2131
2132         /* get, open session */
2133         session = __ceph_lookup_mds_session(mdsc, mds);
2134         if (!session) {
2135                 session = register_session(mdsc, mds);
2136                 if (IS_ERR(session)) {
2137                         err = PTR_ERR(session);
2138                         goto finish;
2139                 }
2140         }
2141         req->r_session = get_session(session);
2142
2143         dout("do_request mds%d session %p state %s\n", mds, session,
2144              ceph_session_state_name(session->s_state));
2145         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2146             session->s_state != CEPH_MDS_SESSION_HUNG) {
2147                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2148                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2149                         __open_session(mdsc, session);
2150                 list_add(&req->r_wait, &session->s_waiting);
2151                 goto out_session;
2152         }
2153
2154         /* send request */
2155         req->r_resend_mds = -1;   /* forget any previous mds hint */
2156
2157         if (req->r_request_started == 0)   /* note request start time */
2158                 req->r_request_started = jiffies;
2159
2160         err = __prepare_send_request(mdsc, req, mds, false);
2161         if (!err) {
2162                 ceph_msg_get(req->r_request);
2163                 ceph_con_send(&session->s_con, req->r_request);
2164         }
2165
2166 out_session:
2167         ceph_put_mds_session(session);
2168 out:
2169         return err;
2170
2171 finish:
2172         req->r_err = err;
2173         complete_request(mdsc, req);
2174         goto out;
2175 }
2176
2177 /*
2178  * called under mdsc->mutex
2179  */
2180 static void __wake_requests(struct ceph_mds_client *mdsc,
2181                             struct list_head *head)
2182 {
2183         struct ceph_mds_request *req;
2184         LIST_HEAD(tmp_list);
2185
2186         list_splice_init(head, &tmp_list);
2187
2188         while (!list_empty(&tmp_list)) {
2189                 req = list_entry(tmp_list.next,
2190                                  struct ceph_mds_request, r_wait);
2191                 list_del_init(&req->r_wait);
2192                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2193                 __do_request(mdsc, req);
2194         }
2195 }
2196
2197 /*
2198  * Wake up threads with requests pending for @mds, so that they can
2199  * resubmit their requests to a possibly different mds.
2200  */
2201 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2202 {
2203         struct ceph_mds_request *req;
2204         struct rb_node *p = rb_first(&mdsc->request_tree);
2205
2206         dout("kick_requests mds%d\n", mds);
2207         while (p) {
2208                 req = rb_entry(p, struct ceph_mds_request, r_node);
2209                 p = rb_next(p);
2210                 if (req->r_got_unsafe)
2211                         continue;
2212                 if (req->r_attempts > 0)
2213                         continue; /* only new requests */
2214                 if (req->r_session &&
2215                     req->r_session->s_mds == mds) {
2216                         dout(" kicking tid %llu\n", req->r_tid);
2217                         list_del_init(&req->r_wait);
2218                         __do_request(mdsc, req);
2219                 }
2220         }
2221 }
2222
2223 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2224                               struct ceph_mds_request *req)
2225 {
2226         dout("submit_request on %p\n", req);
2227         mutex_lock(&mdsc->mutex);
2228         __register_request(mdsc, req, NULL);
2229         __do_request(mdsc, req);
2230         mutex_unlock(&mdsc->mutex);
2231 }
2232
2233 /*
2234  * Synchrously perform an mds request.  Take care of all of the
2235  * session setup, forwarding, retry details.
2236  */
2237 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2238                          struct inode *dir,
2239                          struct ceph_mds_request *req)
2240 {
2241         int err;
2242
2243         dout("do_request on %p\n", req);
2244
2245         /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2246         if (req->r_inode)
2247                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2248         if (req->r_locked_dir)
2249                 ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2250         if (req->r_old_dentry_dir)
2251                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2252                                   CEPH_CAP_PIN);
2253
2254         /* issue */
2255         mutex_lock(&mdsc->mutex);
2256         __register_request(mdsc, req, dir);
2257         __do_request(mdsc, req);
2258
2259         if (req->r_err) {
2260                 err = req->r_err;
2261                 __unregister_request(mdsc, req);
2262                 dout("do_request early error %d\n", err);
2263                 goto out;
2264         }
2265
2266         /* wait */
2267         mutex_unlock(&mdsc->mutex);
2268         dout("do_request waiting\n");
2269         if (!req->r_timeout && req->r_wait_for_completion) {
2270                 err = req->r_wait_for_completion(mdsc, req);
2271         } else {
2272                 long timeleft = wait_for_completion_killable_timeout(
2273                                         &req->r_completion,
2274                                         ceph_timeout_jiffies(req->r_timeout));
2275                 if (timeleft > 0)
2276                         err = 0;
2277                 else if (!timeleft)
2278                         err = -EIO;  /* timed out */
2279                 else
2280                         err = timeleft;  /* killed */
2281         }
2282         dout("do_request waited, got %d\n", err);
2283         mutex_lock(&mdsc->mutex);
2284
2285         /* only abort if we didn't race with a real reply */
2286         if (req->r_got_result) {
2287                 err = le32_to_cpu(req->r_reply_info.head->result);
2288         } else if (err < 0) {
2289                 dout("aborted request %lld with %d\n", req->r_tid, err);
2290
2291                 /*
2292                  * ensure we aren't running concurrently with
2293                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2294                  * rely on locks (dir mutex) held by our caller.
2295                  */
2296                 mutex_lock(&req->r_fill_mutex);
2297                 req->r_err = err;
2298                 req->r_aborted = true;
2299                 mutex_unlock(&req->r_fill_mutex);
2300
2301                 if (req->r_locked_dir &&
2302                     (req->r_op & CEPH_MDS_OP_WRITE))
2303                         ceph_invalidate_dir_request(req);
2304         } else {
2305                 err = req->r_err;
2306         }
2307
2308 out:
2309         mutex_unlock(&mdsc->mutex);
2310         dout("do_request %p done, result %d\n", req, err);
2311         return err;
2312 }
2313
2314 /*
2315  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2316  * namespace request.
2317  */
2318 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2319 {
2320         struct inode *inode = req->r_locked_dir;
2321
2322         dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2323
2324         ceph_dir_clear_complete(inode);
2325         if (req->r_dentry)
2326                 ceph_invalidate_dentry_lease(req->r_dentry);
2327         if (req->r_old_dentry)
2328                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2329 }
2330
2331 /*
2332  * Handle mds reply.
2333  *
2334  * We take the session mutex and parse and process the reply immediately.
2335  * This preserves the logical ordering of replies, capabilities, etc., sent
2336  * by the MDS as they are applied to our local cache.
2337  */
2338 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2339 {
2340         struct ceph_mds_client *mdsc = session->s_mdsc;
2341         struct ceph_mds_request *req;
2342         struct ceph_mds_reply_head *head = msg->front.iov_base;
2343         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2344         struct ceph_snap_realm *realm;
2345         u64 tid;
2346         int err, result;
2347         int mds = session->s_mds;
2348
2349         if (msg->front.iov_len < sizeof(*head)) {
2350                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2351                 ceph_msg_dump(msg);
2352                 return;
2353         }
2354
2355         /* get request, session */
2356         tid = le64_to_cpu(msg->hdr.tid);
2357         mutex_lock(&mdsc->mutex);
2358         req = __lookup_request(mdsc, tid);
2359         if (!req) {
2360                 dout("handle_reply on unknown tid %llu\n", tid);
2361                 mutex_unlock(&mdsc->mutex);
2362                 return;
2363         }
2364         dout("handle_reply %p\n", req);
2365
2366         /* correct session? */
2367         if (req->r_session != session) {
2368                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2369                        " not mds%d\n", tid, session->s_mds,
2370                        req->r_session ? req->r_session->s_mds : -1);
2371                 mutex_unlock(&mdsc->mutex);
2372                 goto out;
2373         }
2374
2375         /* dup? */
2376         if ((req->r_got_unsafe && !head->safe) ||
2377             (req->r_got_safe && head->safe)) {
2378                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2379                            head->safe ? "safe" : "unsafe", tid, mds);
2380                 mutex_unlock(&mdsc->mutex);
2381                 goto out;
2382         }
2383         if (req->r_got_safe && !head->safe) {
2384                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2385                            tid, mds);
2386                 mutex_unlock(&mdsc->mutex);
2387                 goto out;
2388         }
2389
2390         result = le32_to_cpu(head->result);
2391
2392         /*
2393          * Handle an ESTALE
2394          * if we're not talking to the authority, send to them
2395          * if the authority has changed while we weren't looking,
2396          * send to new authority
2397          * Otherwise we just have to return an ESTALE
2398          */
2399         if (result == -ESTALE) {
2400                 dout("got ESTALE on request %llu", req->r_tid);
2401                 req->r_resend_mds = -1;
2402                 if (req->r_direct_mode != USE_AUTH_MDS) {
2403                         dout("not using auth, setting for that now");
2404                         req->r_direct_mode = USE_AUTH_MDS;
2405                         __do_request(mdsc, req);
2406                         mutex_unlock(&mdsc->mutex);
2407                         goto out;
2408                 } else  {
2409                         int mds = __choose_mds(mdsc, req);
2410                         if (mds >= 0 && mds != req->r_session->s_mds) {
2411                                 dout("but auth changed, so resending");
2412                                 __do_request(mdsc, req);
2413                                 mutex_unlock(&mdsc->mutex);
2414                                 goto out;
2415                         }
2416                 }
2417                 dout("have to return ESTALE on request %llu", req->r_tid);
2418         }
2419
2420
2421         if (head->safe) {
2422                 req->r_got_safe = true;
2423                 __unregister_request(mdsc, req);
2424
2425                 if (req->r_got_unsafe) {
2426                         /*
2427                          * We already handled the unsafe response, now do the
2428                          * cleanup.  No need to examine the response; the MDS
2429                          * doesn't include any result info in the safe
2430                          * response.  And even if it did, there is nothing
2431                          * useful we could do with a revised return value.
2432                          */
2433                         dout("got safe reply %llu, mds%d\n", tid, mds);
2434                         list_del_init(&req->r_unsafe_item);
2435
2436                         /* last unsafe request during umount? */
2437                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2438                                 complete_all(&mdsc->safe_umount_waiters);
2439                         mutex_unlock(&mdsc->mutex);
2440                         goto out;
2441                 }
2442         } else {
2443                 req->r_got_unsafe = true;
2444                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2445         }
2446
2447         dout("handle_reply tid %lld result %d\n", tid, result);
2448         rinfo = &req->r_reply_info;
2449         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2450         mutex_unlock(&mdsc->mutex);
2451
2452         mutex_lock(&session->s_mutex);
2453         if (err < 0) {
2454                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2455                 ceph_msg_dump(msg);
2456                 goto out_err;
2457         }
2458
2459         /* snap trace */
2460         realm = NULL;
2461         if (rinfo->snapblob_len) {
2462                 down_write(&mdsc->snap_rwsem);
2463                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2464                                 rinfo->snapblob + rinfo->snapblob_len,
2465                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2466                                 &realm);
2467                 downgrade_write(&mdsc->snap_rwsem);
2468         } else {
2469                 down_read(&mdsc->snap_rwsem);
2470         }
2471
2472         /* insert trace into our cache */
2473         mutex_lock(&req->r_fill_mutex);
2474         err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2475         if (err == 0) {
2476                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2477                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2478                         ceph_readdir_prepopulate(req, req->r_session);
2479                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2480         }
2481         mutex_unlock(&req->r_fill_mutex);
2482
2483         up_read(&mdsc->snap_rwsem);
2484         if (realm)
2485                 ceph_put_snap_realm(mdsc, realm);
2486 out_err:
2487         mutex_lock(&mdsc->mutex);
2488         if (!req->r_aborted) {
2489                 if (err) {
2490                         req->r_err = err;
2491                 } else {
2492                         req->r_reply = msg;
2493                         ceph_msg_get(msg);
2494                         req->r_got_result = true;
2495                 }
2496         } else {
2497                 dout("reply arrived after request %lld was aborted\n", tid);
2498         }
2499         mutex_unlock(&mdsc->mutex);
2500
2501         mutex_unlock(&session->s_mutex);
2502
2503         /* kick calling process */
2504         complete_request(mdsc, req);
2505 out:
2506         ceph_mdsc_put_request(req);
2507         return;
2508 }
2509
2510
2511
2512 /*
2513  * handle mds notification that our request has been forwarded.
2514  */
2515 static void handle_forward(struct ceph_mds_client *mdsc,
2516                            struct ceph_mds_session *session,
2517                            struct ceph_msg *msg)
2518 {
2519         struct ceph_mds_request *req;
2520         u64 tid = le64_to_cpu(msg->hdr.tid);
2521         u32 next_mds;
2522         u32 fwd_seq;
2523         int err = -EINVAL;
2524         void *p = msg->front.iov_base;
2525         void *end = p + msg->front.iov_len;
2526
2527         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2528         next_mds = ceph_decode_32(&p);
2529         fwd_seq = ceph_decode_32(&p);
2530
2531         mutex_lock(&mdsc->mutex);
2532         req = __lookup_request(mdsc, tid);
2533         if (!req) {
2534                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2535                 goto out;  /* dup reply? */
2536         }
2537
2538         if (req->r_aborted) {
2539                 dout("forward tid %llu aborted, unregistering\n", tid);
2540                 __unregister_request(mdsc, req);
2541         } else if (fwd_seq <= req->r_num_fwd) {
2542                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2543                      tid, next_mds, req->r_num_fwd, fwd_seq);
2544         } else {
2545                 /* resend. forward race not possible; mds would drop */
2546                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2547                 BUG_ON(req->r_err);
2548                 BUG_ON(req->r_got_result);
2549                 req->r_attempts = 0;
2550                 req->r_num_fwd = fwd_seq;
2551                 req->r_resend_mds = next_mds;
2552                 put_request_session(req);
2553                 __do_request(mdsc, req);
2554         }
2555         ceph_mdsc_put_request(req);
2556 out:
2557         mutex_unlock(&mdsc->mutex);
2558         return;
2559
2560 bad:
2561         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2562 }
2563
2564 /*
2565  * handle a mds session control message
2566  */
2567 static void handle_session(struct ceph_mds_session *session,
2568                            struct ceph_msg *msg)
2569 {
2570         struct ceph_mds_client *mdsc = session->s_mdsc;
2571         u32 op;
2572         u64 seq;
2573         int mds = session->s_mds;
2574         struct ceph_mds_session_head *h = msg->front.iov_base;
2575         int wake = 0;
2576
2577         /* decode */
2578         if (msg->front.iov_len != sizeof(*h))
2579                 goto bad;
2580         op = le32_to_cpu(h->op);
2581         seq = le64_to_cpu(h->seq);
2582
2583         mutex_lock(&mdsc->mutex);
2584         if (op == CEPH_SESSION_CLOSE)
2585                 __unregister_session(mdsc, session);
2586         /* FIXME: this ttl calculation is generous */
2587         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2588         mutex_unlock(&mdsc->mutex);
2589
2590         mutex_lock(&session->s_mutex);
2591
2592         dout("handle_session mds%d %s %p state %s seq %llu\n",
2593              mds, ceph_session_op_name(op), session,
2594              ceph_session_state_name(session->s_state), seq);
2595
2596         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2597                 session->s_state = CEPH_MDS_SESSION_OPEN;
2598                 pr_info("mds%d came back\n", session->s_mds);
2599         }
2600
2601         switch (op) {
2602         case CEPH_SESSION_OPEN:
2603                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2604                         pr_info("mds%d reconnect success\n", session->s_mds);
2605                 session->s_state = CEPH_MDS_SESSION_OPEN;
2606                 renewed_caps(mdsc, session, 0);
2607                 wake = 1;
2608                 if (mdsc->stopping)
2609                         __close_session(mdsc, session);
2610                 break;
2611
2612         case CEPH_SESSION_RENEWCAPS:
2613                 if (session->s_renew_seq == seq)
2614                         renewed_caps(mdsc, session, 1);
2615                 break;
2616
2617         case CEPH_SESSION_CLOSE:
2618                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2619                         pr_info("mds%d reconnect denied\n", session->s_mds);
2620                 cleanup_session_requests(mdsc, session);
2621                 remove_session_caps(session);
2622                 wake = 2; /* for good measure */
2623                 wake_up_all(&mdsc->session_close_wq);
2624                 break;
2625
2626         case CEPH_SESSION_STALE:
2627                 pr_info("mds%d caps went stale, renewing\n",
2628                         session->s_mds);
2629                 spin_lock(&session->s_gen_ttl_lock);
2630                 session->s_cap_gen++;
2631                 session->s_cap_ttl = jiffies - 1;
2632                 spin_unlock(&session->s_gen_ttl_lock);
2633                 send_renew_caps(mdsc, session);
2634                 break;
2635
2636         case CEPH_SESSION_RECALL_STATE:
2637                 trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2638                 break;
2639
2640         case CEPH_SESSION_FLUSHMSG:
2641                 send_flushmsg_ack(mdsc, session, seq);
2642                 break;
2643
2644         case CEPH_SESSION_FORCE_RO:
2645                 dout("force_session_readonly %p\n", session);
2646                 spin_lock(&session->s_cap_lock);
2647                 session->s_readonly = true;
2648                 spin_unlock(&session->s_cap_lock);
2649                 wake_up_session_caps(session, 0);
2650                 break;
2651
2652         default:
2653                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2654                 WARN_ON(1);
2655         }
2656
2657         mutex_unlock(&session->s_mutex);
2658         if (wake) {
2659                 mutex_lock(&mdsc->mutex);
2660                 __wake_requests(mdsc, &session->s_waiting);
2661                 if (wake == 2)
2662                         kick_requests(mdsc, mds);
2663                 mutex_unlock(&mdsc->mutex);
2664         }
2665         return;
2666
2667 bad:
2668         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2669                (int)msg->front.iov_len);
2670         ceph_msg_dump(msg);
2671         return;
2672 }
2673
2674
2675 /*
2676  * called under session->mutex.
2677  */
2678 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2679                                    struct ceph_mds_session *session)
2680 {
2681         struct ceph_mds_request *req, *nreq;
2682         struct rb_node *p;
2683         int err;
2684
2685         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2686
2687         mutex_lock(&mdsc->mutex);
2688         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2689                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
2690                 if (!err) {
2691                         ceph_msg_get(req->r_request);
2692                         ceph_con_send(&session->s_con, req->r_request);
2693                 }
2694         }
2695
2696         /*
2697          * also re-send old requests when MDS enters reconnect stage. So that MDS
2698          * can process completed request in clientreplay stage.
2699          */
2700         p = rb_first(&mdsc->request_tree);
2701         while (p) {
2702                 req = rb_entry(p, struct ceph_mds_request, r_node);
2703                 p = rb_next(p);
2704                 if (req->r_got_unsafe)
2705                         continue;
2706                 if (req->r_attempts == 0)
2707                         continue; /* only old requests */
2708                 if (req->r_session &&
2709                     req->r_session->s_mds == session->s_mds) {
2710                         err = __prepare_send_request(mdsc, req,
2711                                                      session->s_mds, true);
2712                         if (!err) {
2713                                 ceph_msg_get(req->r_request);
2714                                 ceph_con_send(&session->s_con, req->r_request);
2715                         }
2716                 }
2717         }
2718         mutex_unlock(&mdsc->mutex);
2719 }
2720
2721 /*
2722  * Encode information about a cap for a reconnect with the MDS.
2723  */
2724 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2725                           void *arg)
2726 {
2727         union {
2728                 struct ceph_mds_cap_reconnect v2;
2729                 struct ceph_mds_cap_reconnect_v1 v1;
2730         } rec;
2731         size_t reclen;
2732         struct ceph_inode_info *ci;
2733         struct ceph_reconnect_state *recon_state = arg;
2734         struct ceph_pagelist *pagelist = recon_state->pagelist;
2735         char *path;
2736         int pathlen, err;
2737         u64 pathbase;
2738         struct dentry *dentry;
2739
2740         ci = cap->ci;
2741
2742         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2743              inode, ceph_vinop(inode), cap, cap->cap_id,
2744              ceph_cap_string(cap->issued));
2745         err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2746         if (err)
2747                 return err;
2748
2749         dentry = d_find_alias(inode);
2750         if (dentry) {
2751                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2752                 if (IS_ERR(path)) {
2753                         err = PTR_ERR(path);
2754                         goto out_dput;
2755                 }
2756         } else {
2757                 path = NULL;
2758                 pathlen = 0;
2759         }
2760         err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2761         if (err)
2762                 goto out_free;
2763
2764         spin_lock(&ci->i_ceph_lock);
2765         cap->seq = 0;        /* reset cap seq */
2766         cap->issue_seq = 0;  /* and issue_seq */
2767         cap->mseq = 0;       /* and migrate_seq */
2768         cap->cap_gen = cap->session->s_cap_gen;
2769
2770         if (recon_state->flock) {
2771                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2772                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2773                 rec.v2.issued = cpu_to_le32(cap->issued);
2774                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2775                 rec.v2.pathbase = cpu_to_le64(pathbase);
2776                 rec.v2.flock_len = 0;
2777                 reclen = sizeof(rec.v2);
2778         } else {
2779                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2780                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2781                 rec.v1.issued = cpu_to_le32(cap->issued);
2782                 rec.v1.size = cpu_to_le64(inode->i_size);
2783                 ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2784                 ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2785                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2786                 rec.v1.pathbase = cpu_to_le64(pathbase);
2787                 reclen = sizeof(rec.v1);
2788         }
2789         spin_unlock(&ci->i_ceph_lock);
2790
2791         if (recon_state->flock) {
2792                 int num_fcntl_locks, num_flock_locks;
2793                 struct ceph_filelock *flocks;
2794
2795 encode_again:
2796                 ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2797                 flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2798                                  sizeof(struct ceph_filelock), GFP_NOFS);
2799                 if (!flocks) {
2800                         err = -ENOMEM;
2801                         goto out_free;
2802                 }
2803                 err = ceph_encode_locks_to_buffer(inode, flocks,
2804                                                   num_fcntl_locks,
2805                                                   num_flock_locks);
2806                 if (err) {
2807                         kfree(flocks);
2808                         if (err == -ENOSPC)
2809                                 goto encode_again;
2810                         goto out_free;
2811                 }
2812                 /*
2813                  * number of encoded locks is stable, so copy to pagelist
2814                  */
2815                 rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2816                                     (num_fcntl_locks+num_flock_locks) *
2817                                     sizeof(struct ceph_filelock));
2818                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2819                 if (!err)
2820                         err = ceph_locks_to_pagelist(flocks, pagelist,
2821                                                      num_fcntl_locks,
2822                                                      num_flock_locks);
2823                 kfree(flocks);
2824         } else {
2825                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2826         }
2827
2828         recon_state->nr_caps++;
2829 out_free:
2830         kfree(path);
2831 out_dput:
2832         dput(dentry);
2833         return err;
2834 }
2835
2836
2837 /*
2838  * If an MDS fails and recovers, clients need to reconnect in order to
2839  * reestablish shared state.  This includes all caps issued through
2840  * this session _and_ the snap_realm hierarchy.  Because it's not
2841  * clear which snap realms the mds cares about, we send everything we
2842  * know about.. that ensures we'll then get any new info the
2843  * recovering MDS might have.
2844  *
2845  * This is a relatively heavyweight operation, but it's rare.
2846  *
2847  * called with mdsc->mutex held.
2848  */
2849 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2850                                struct ceph_mds_session *session)
2851 {
2852         struct ceph_msg *reply;
2853         struct rb_node *p;
2854         int mds = session->s_mds;
2855         int err = -ENOMEM;
2856         int s_nr_caps;
2857         struct ceph_pagelist *pagelist;
2858         struct ceph_reconnect_state recon_state;
2859
2860         pr_info("mds%d reconnect start\n", mds);
2861
2862         pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2863         if (!pagelist)
2864                 goto fail_nopagelist;
2865         ceph_pagelist_init(pagelist);
2866
2867         reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2868         if (!reply)
2869                 goto fail_nomsg;
2870
2871         mutex_lock(&session->s_mutex);
2872         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2873         session->s_seq = 0;
2874
2875         dout("session %p state %s\n", session,
2876              ceph_session_state_name(session->s_state));
2877
2878         spin_lock(&session->s_gen_ttl_lock);
2879         session->s_cap_gen++;
2880         spin_unlock(&session->s_gen_ttl_lock);
2881
2882         spin_lock(&session->s_cap_lock);
2883         /* don't know if session is readonly */
2884         session->s_readonly = 0;
2885         /*
2886          * notify __ceph_remove_cap() that we are composing cap reconnect.
2887          * If a cap get released before being added to the cap reconnect,
2888          * __ceph_remove_cap() should skip queuing cap release.
2889          */
2890         session->s_cap_reconnect = 1;
2891         /* drop old cap expires; we're about to reestablish that state */
2892         cleanup_cap_releases(mdsc, session);
2893
2894         /* trim unused caps to reduce MDS's cache rejoin time */
2895         if (mdsc->fsc->sb->s_root)
2896                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
2897
2898         ceph_con_close(&session->s_con);
2899         ceph_con_open(&session->s_con,
2900                       CEPH_ENTITY_TYPE_MDS, mds,
2901                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2902
2903         /* replay unsafe requests */
2904         replay_unsafe_requests(mdsc, session);
2905
2906         down_read(&mdsc->snap_rwsem);
2907
2908         /* traverse this session's caps */
2909         s_nr_caps = session->s_nr_caps;
2910         err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2911         if (err)
2912                 goto fail;
2913
2914         recon_state.nr_caps = 0;
2915         recon_state.pagelist = pagelist;
2916         recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2917         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2918         if (err < 0)
2919                 goto fail;
2920
2921         spin_lock(&session->s_cap_lock);
2922         session->s_cap_reconnect = 0;
2923         spin_unlock(&session->s_cap_lock);
2924
2925         /*
2926          * snaprealms.  we provide mds with the ino, seq (version), and
2927          * parent for all of our realms.  If the mds has any newer info,
2928          * it will tell us.
2929          */
2930         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2931                 struct ceph_snap_realm *realm =
2932                         rb_entry(p, struct ceph_snap_realm, node);
2933                 struct ceph_mds_snaprealm_reconnect sr_rec;
2934
2935                 dout(" adding snap realm %llx seq %lld parent %llx\n",
2936                      realm->ino, realm->seq, realm->parent_ino);
2937                 sr_rec.ino = cpu_to_le64(realm->ino);
2938                 sr_rec.seq = cpu_to_le64(realm->seq);
2939                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
2940                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2941                 if (err)
2942                         goto fail;
2943         }
2944
2945         if (recon_state.flock)
2946                 reply->hdr.version = cpu_to_le16(2);
2947
2948         /* raced with cap release? */
2949         if (s_nr_caps != recon_state.nr_caps) {
2950                 struct page *page = list_first_entry(&pagelist->head,
2951                                                      struct page, lru);
2952                 __le32 *addr = kmap_atomic(page);
2953                 *addr = cpu_to_le32(recon_state.nr_caps);
2954                 kunmap_atomic(addr);
2955         }
2956
2957         reply->hdr.data_len = cpu_to_le32(pagelist->length);
2958         ceph_msg_data_add_pagelist(reply, pagelist);
2959         ceph_con_send(&session->s_con, reply);
2960
2961         mutex_unlock(&session->s_mutex);
2962
2963         mutex_lock(&mdsc->mutex);
2964         __wake_requests(mdsc, &session->s_waiting);
2965         mutex_unlock(&mdsc->mutex);
2966
2967         up_read(&mdsc->snap_rwsem);
2968         return;
2969
2970 fail:
2971         ceph_msg_put(reply);
2972         up_read(&mdsc->snap_rwsem);
2973         mutex_unlock(&session->s_mutex);
2974 fail_nomsg:
2975         ceph_pagelist_release(pagelist);
2976 fail_nopagelist:
2977         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
2978         return;
2979 }
2980
2981
2982 /*
2983  * compare old and new mdsmaps, kicking requests
2984  * and closing out old connections as necessary
2985  *
2986  * called under mdsc->mutex.
2987  */
2988 static void check_new_map(struct ceph_mds_client *mdsc,
2989                           struct ceph_mdsmap *newmap,
2990                           struct ceph_mdsmap *oldmap)
2991 {
2992         int i;
2993         int oldstate, newstate;
2994         struct ceph_mds_session *s;
2995
2996         dout("check_new_map new %u old %u\n",
2997              newmap->m_epoch, oldmap->m_epoch);
2998
2999         for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
3000                 if (mdsc->sessions[i] == NULL)
3001                         continue;
3002                 s = mdsc->sessions[i];
3003                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3004                 newstate = ceph_mdsmap_get_state(newmap, i);
3005
3006                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3007                      i, ceph_mds_state_name(oldstate),
3008                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3009                      ceph_mds_state_name(newstate),
3010                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3011                      ceph_session_state_name(s->s_state));
3012
3013                 if (i >= newmap->m_max_mds ||
3014                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
3015                            ceph_mdsmap_get_addr(newmap, i),
3016                            sizeof(struct ceph_entity_addr))) {
3017                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
3018                                 /* the session never opened, just close it
3019                                  * out now */
3020                                 __wake_requests(mdsc, &s->s_waiting);
3021                                 __unregister_session(mdsc, s);
3022                         } else {
3023                                 /* just close it */
3024                                 mutex_unlock(&mdsc->mutex);
3025                                 mutex_lock(&s->s_mutex);
3026                                 mutex_lock(&mdsc->mutex);
3027                                 ceph_con_close(&s->s_con);
3028                                 mutex_unlock(&s->s_mutex);
3029                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
3030                         }
3031                 } else if (oldstate == newstate) {
3032                         continue;  /* nothing new with this mds */
3033                 }
3034
3035                 /*
3036                  * send reconnect?
3037                  */
3038                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3039                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3040                         mutex_unlock(&mdsc->mutex);
3041                         send_mds_reconnect(mdsc, s);
3042                         mutex_lock(&mdsc->mutex);
3043                 }
3044
3045                 /*
3046                  * kick request on any mds that has gone active.
3047                  */
3048                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3049                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3050                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3051                             oldstate != CEPH_MDS_STATE_STARTING)
3052                                 pr_info("mds%d recovery completed\n", s->s_mds);
3053                         kick_requests(mdsc, i);
3054                         ceph_kick_flushing_caps(mdsc, s);
3055                         wake_up_session_caps(s, 1);
3056                 }
3057         }
3058
3059         for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3060                 s = mdsc->sessions[i];
3061                 if (!s)
3062                         continue;
3063                 if (!ceph_mdsmap_is_laggy(newmap, i))
3064                         continue;
3065                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3066                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3067                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3068                         dout(" connecting to export targets of laggy mds%d\n",
3069                              i);
3070                         __open_export_target_sessions(mdsc, s);
3071                 }
3072         }
3073 }
3074
3075
3076
3077 /*
3078  * leases
3079  */
3080
3081 /*
3082  * caller must hold session s_mutex, dentry->d_lock
3083  */
3084 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3085 {
3086         struct ceph_dentry_info *di = ceph_dentry(dentry);
3087
3088         ceph_put_mds_session(di->lease_session);
3089         di->lease_session = NULL;
3090 }
3091
3092 static void handle_lease(struct ceph_mds_client *mdsc,
3093                          struct ceph_mds_session *session,
3094                          struct ceph_msg *msg)
3095 {
3096         struct super_block *sb = mdsc->fsc->sb;
3097         struct inode *inode;
3098         struct dentry *parent, *dentry;
3099         struct ceph_dentry_info *di;
3100         int mds = session->s_mds;
3101         struct ceph_mds_lease *h = msg->front.iov_base;
3102         u32 seq;
3103         struct ceph_vino vino;
3104         struct qstr dname;
3105         int release = 0;
3106
3107         dout("handle_lease from mds%d\n", mds);
3108
3109         /* decode */
3110         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3111                 goto bad;
3112         vino.ino = le64_to_cpu(h->ino);
3113         vino.snap = CEPH_NOSNAP;
3114         seq = le32_to_cpu(h->seq);
3115         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3116         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3117         if (dname.len != get_unaligned_le32(h+1))
3118                 goto bad;
3119
3120         /* lookup inode */
3121         inode = ceph_find_inode(sb, vino);
3122         dout("handle_lease %s, ino %llx %p %.*s\n",
3123              ceph_lease_op_name(h->action), vino.ino, inode,
3124              dname.len, dname.name);
3125
3126         mutex_lock(&session->s_mutex);
3127         session->s_seq++;
3128
3129         if (inode == NULL) {
3130                 dout("handle_lease no inode %llx\n", vino.ino);
3131                 goto release;
3132         }
3133
3134         /* dentry */
3135         parent = d_find_alias(inode);
3136         if (!parent) {
3137                 dout("no parent dentry on inode %p\n", inode);
3138                 WARN_ON(1);
3139                 goto release;  /* hrm... */
3140         }
3141         dname.hash = full_name_hash(dname.name, dname.len);
3142         dentry = d_lookup(parent, &dname);
3143         dput(parent);
3144         if (!dentry)
3145                 goto release;
3146
3147         spin_lock(&dentry->d_lock);
3148         di = ceph_dentry(dentry);
3149         switch (h->action) {
3150         case CEPH_MDS_LEASE_REVOKE:
3151                 if (di->lease_session == session) {
3152                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3153                                 h->seq = cpu_to_le32(di->lease_seq);
3154                         __ceph_mdsc_drop_dentry_lease(dentry);
3155                 }
3156                 release = 1;
3157                 break;
3158
3159         case CEPH_MDS_LEASE_RENEW:
3160                 if (di->lease_session == session &&
3161                     di->lease_gen == session->s_cap_gen &&
3162                     di->lease_renew_from &&
3163                     di->lease_renew_after == 0) {
3164                         unsigned long duration =
3165                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3166
3167                         di->lease_seq = seq;
3168                         dentry->d_time = di->lease_renew_from + duration;
3169                         di->lease_renew_after = di->lease_renew_from +
3170                                 (duration >> 1);
3171                         di->lease_renew_from = 0;
3172                 }
3173                 break;
3174         }
3175         spin_unlock(&dentry->d_lock);
3176         dput(dentry);
3177
3178         if (!release)
3179                 goto out;
3180
3181 release:
3182         /* let's just reuse the same message */
3183         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3184         ceph_msg_get(msg);
3185         ceph_con_send(&session->s_con, msg);
3186
3187 out:
3188         iput(inode);
3189         mutex_unlock(&session->s_mutex);
3190         return;
3191
3192 bad:
3193         pr_err("corrupt lease message\n");
3194         ceph_msg_dump(msg);
3195 }
3196
3197 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3198                               struct inode *inode,
3199                               struct dentry *dentry, char action,
3200                               u32 seq)
3201 {
3202         struct ceph_msg *msg;
3203         struct ceph_mds_lease *lease;
3204         int len = sizeof(*lease) + sizeof(u32);
3205         int dnamelen = 0;
3206
3207         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3208              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3209         dnamelen = dentry->d_name.len;
3210         len += dnamelen;
3211
3212         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3213         if (!msg)
3214                 return;
3215         lease = msg->front.iov_base;
3216         lease->action = action;
3217         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3218         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3219         lease->seq = cpu_to_le32(seq);
3220         put_unaligned_le32(dnamelen, lease + 1);
3221         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3222
3223         /*
3224          * if this is a preemptive lease RELEASE, no need to
3225          * flush request stream, since the actual request will
3226          * soon follow.
3227          */
3228         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3229
3230         ceph_con_send(&session->s_con, msg);
3231 }
3232
3233 /*
3234  * Preemptively release a lease we expect to invalidate anyway.
3235  * Pass @inode always, @dentry is optional.
3236  */
3237 void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
3238                              struct dentry *dentry)
3239 {
3240         struct ceph_dentry_info *di;
3241         struct ceph_mds_session *session;
3242         u32 seq;
3243
3244         BUG_ON(inode == NULL);
3245         BUG_ON(dentry == NULL);
3246
3247         /* is dentry lease valid? */
3248         spin_lock(&dentry->d_lock);
3249         di = ceph_dentry(dentry);
3250         if (!di || !di->lease_session ||
3251             di->lease_session->s_mds < 0 ||
3252             di->lease_gen != di->lease_session->s_cap_gen ||
3253             !time_before(jiffies, dentry->d_time)) {
3254                 dout("lease_release inode %p dentry %p -- "
3255                      "no lease\n",
3256                      inode, dentry);
3257                 spin_unlock(&dentry->d_lock);
3258                 return;
3259         }
3260
3261         /* we do have a lease on this dentry; note mds and seq */
3262         session = ceph_get_mds_session(di->lease_session);
3263         seq = di->lease_seq;
3264         __ceph_mdsc_drop_dentry_lease(dentry);
3265         spin_unlock(&dentry->d_lock);
3266
3267         dout("lease_release inode %p dentry %p to mds%d\n",
3268              inode, dentry, session->s_mds);
3269         ceph_mdsc_lease_send_msg(session, inode, dentry,
3270                                  CEPH_MDS_LEASE_RELEASE, seq);
3271         ceph_put_mds_session(session);
3272 }
3273
3274 /*
3275  * drop all leases (and dentry refs) in preparation for umount
3276  */
3277 static void drop_leases(struct ceph_mds_client *mdsc)
3278 {
3279         int i;
3280
3281         dout("drop_leases\n");
3282         mutex_lock(&mdsc->mutex);
3283         for (i = 0; i < mdsc->max_sessions; i++) {
3284                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3285                 if (!s)
3286                         continue;
3287                 mutex_unlock(&mdsc->mutex);
3288                 mutex_lock(&s->s_mutex);
3289                 mutex_unlock(&s->s_mutex);
3290                 ceph_put_mds_session(s);
3291                 mutex_lock(&mdsc->mutex);
3292         }
3293         mutex_unlock(&mdsc->mutex);
3294 }
3295
3296
3297
3298 /*
3299  * delayed work -- periodically trim expired leases, renew caps with mds
3300  */
3301 static void schedule_delayed(struct ceph_mds_client *mdsc)
3302 {
3303         int delay = 5;
3304         unsigned hz = round_jiffies_relative(HZ * delay);
3305         schedule_delayed_work(&mdsc->delayed_work, hz);
3306 }
3307
3308 static void delayed_work(struct work_struct *work)
3309 {
3310         int i;
3311         struct ceph_mds_client *mdsc =
3312                 container_of(work, struct ceph_mds_client, delayed_work.work);
3313         int renew_interval;
3314         int renew_caps;
3315
3316         dout("mdsc delayed_work\n");
3317         ceph_check_delayed_caps(mdsc);
3318
3319         mutex_lock(&mdsc->mutex);
3320         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3321         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3322                                    mdsc->last_renew_caps);
3323         if (renew_caps)
3324                 mdsc->last_renew_caps = jiffies;
3325
3326         for (i = 0; i < mdsc->max_sessions; i++) {
3327                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3328                 if (s == NULL)
3329                         continue;
3330                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3331                         dout("resending session close request for mds%d\n",
3332                              s->s_mds);
3333                         request_close_session(mdsc, s);
3334                         ceph_put_mds_session(s);
3335                         continue;
3336                 }
3337                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3338                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3339                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3340                                 pr_info("mds%d hung\n", s->s_mds);
3341                         }
3342                 }
3343                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3344                         /* this mds is failed or recovering, just wait */
3345                         ceph_put_mds_session(s);
3346                         continue;
3347                 }
3348                 mutex_unlock(&mdsc->mutex);
3349
3350                 mutex_lock(&s->s_mutex);
3351                 if (renew_caps)
3352                         send_renew_caps(mdsc, s);
3353                 else
3354                         ceph_con_keepalive(&s->s_con);
3355                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3356                     s->s_state == CEPH_MDS_SESSION_HUNG)
3357                         ceph_send_cap_releases(mdsc, s);
3358                 mutex_unlock(&s->s_mutex);
3359                 ceph_put_mds_session(s);
3360
3361                 mutex_lock(&mdsc->mutex);
3362         }
3363         mutex_unlock(&mdsc->mutex);
3364
3365         schedule_delayed(mdsc);
3366 }
3367
3368 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3369
3370 {
3371         struct ceph_mds_client *mdsc;
3372
3373         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3374         if (!mdsc)
3375                 return -ENOMEM;
3376         mdsc->fsc = fsc;
3377         fsc->mdsc = mdsc;
3378         mutex_init(&mdsc->mutex);
3379         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3380         if (mdsc->mdsmap == NULL) {
3381                 kfree(mdsc);
3382                 return -ENOMEM;
3383         }
3384
3385         init_completion(&mdsc->safe_umount_waiters);
3386         init_waitqueue_head(&mdsc->session_close_wq);
3387         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3388         mdsc->sessions = NULL;
3389         atomic_set(&mdsc->num_sessions, 0);
3390         mdsc->max_sessions = 0;
3391         mdsc->stopping = 0;
3392         mdsc->last_snap_seq = 0;
3393         init_rwsem(&mdsc->snap_rwsem);
3394         mdsc->snap_realms = RB_ROOT;
3395         INIT_LIST_HEAD(&mdsc->snap_empty);
3396         spin_lock_init(&mdsc->snap_empty_lock);
3397         mdsc->last_tid = 0;
3398         mdsc->oldest_tid = 0;
3399         mdsc->request_tree = RB_ROOT;
3400         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3401         mdsc->last_renew_caps = jiffies;
3402         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3403         spin_lock_init(&mdsc->cap_delay_lock);
3404         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3405         spin_lock_init(&mdsc->snap_flush_lock);
3406         mdsc->cap_flush_seq = 0;
3407         INIT_LIST_HEAD(&mdsc->cap_dirty);
3408         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3409         mdsc->num_cap_flushing = 0;
3410         spin_lock_init(&mdsc->cap_dirty_lock);
3411         init_waitqueue_head(&mdsc->cap_flushing_wq);
3412         spin_lock_init(&mdsc->dentry_lru_lock);
3413         INIT_LIST_HEAD(&mdsc->dentry_lru);
3414
3415         ceph_caps_init(mdsc);
3416         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3417
3418         init_rwsem(&mdsc->pool_perm_rwsem);
3419         mdsc->pool_perm_tree = RB_ROOT;
3420
3421         return 0;
3422 }
3423
3424 /*
3425  * Wait for safe replies on open mds requests.  If we time out, drop
3426  * all requests from the tree to avoid dangling dentry refs.
3427  */
3428 static void wait_requests(struct ceph_mds_client *mdsc)
3429 {
3430         struct ceph_options *opts = mdsc->fsc->client->options;
3431         struct ceph_mds_request *req;
3432
3433         mutex_lock(&mdsc->mutex);
3434         if (__get_oldest_req(mdsc)) {
3435                 mutex_unlock(&mdsc->mutex);
3436
3437                 dout("wait_requests waiting for requests\n");
3438                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3439                                     ceph_timeout_jiffies(opts->mount_timeout));
3440
3441                 /* tear down remaining requests */
3442                 mutex_lock(&mdsc->mutex);
3443                 while ((req = __get_oldest_req(mdsc))) {
3444                         dout("wait_requests timed out on tid %llu\n",
3445                              req->r_tid);
3446                         __unregister_request(mdsc, req);
3447                 }
3448         }
3449         mutex_unlock(&mdsc->mutex);
3450         dout("wait_requests done\n");
3451 }
3452
3453 /*
3454  * called before mount is ro, and before dentries are torn down.
3455  * (hmm, does this still race with new lookups?)
3456  */
3457 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3458 {
3459         dout("pre_umount\n");
3460         mdsc->stopping = 1;
3461
3462         drop_leases(mdsc);
3463         ceph_flush_dirty_caps(mdsc);
3464         wait_requests(mdsc);
3465
3466         /*
3467          * wait for reply handlers to drop their request refs and
3468          * their inode/dcache refs
3469          */
3470         ceph_msgr_flush();
3471 }
3472
3473 /*
3474  * wait for all write mds requests to flush.
3475  */
3476 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3477 {
3478         struct ceph_mds_request *req = NULL, *nextreq;
3479         struct rb_node *n;
3480
3481         mutex_lock(&mdsc->mutex);
3482         dout("wait_unsafe_requests want %lld\n", want_tid);
3483 restart:
3484         req = __get_oldest_req(mdsc);
3485         while (req && req->r_tid <= want_tid) {
3486                 /* find next request */
3487                 n = rb_next(&req->r_node);
3488                 if (n)
3489                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3490                 else
3491                         nextreq = NULL;
3492                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
3493                     (req->r_op & CEPH_MDS_OP_WRITE)) {
3494                         /* write op */
3495                         ceph_mdsc_get_request(req);
3496                         if (nextreq)
3497                                 ceph_mdsc_get_request(nextreq);
3498                         mutex_unlock(&mdsc->mutex);
3499                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3500                              req->r_tid, want_tid);
3501                         wait_for_completion(&req->r_safe_completion);
3502                         mutex_lock(&mdsc->mutex);
3503                         ceph_mdsc_put_request(req);
3504                         if (!nextreq)
3505                                 break;  /* next dne before, so we're done! */
3506                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3507                                 /* next request was removed from tree */
3508                                 ceph_mdsc_put_request(nextreq);
3509                                 goto restart;
3510                         }
3511                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3512                 }
3513                 req = nextreq;
3514         }
3515         mutex_unlock(&mdsc->mutex);
3516         dout("wait_unsafe_requests done\n");
3517 }
3518
3519 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3520 {
3521         u64 want_tid, want_flush, want_snap;
3522
3523         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3524                 return;
3525
3526         dout("sync\n");
3527         mutex_lock(&mdsc->mutex);
3528         want_tid = mdsc->last_tid;
3529         mutex_unlock(&mdsc->mutex);
3530
3531         ceph_flush_dirty_caps(mdsc);
3532         spin_lock(&mdsc->cap_dirty_lock);
3533         want_flush = mdsc->cap_flush_seq;
3534         spin_unlock(&mdsc->cap_dirty_lock);
3535
3536         down_read(&mdsc->snap_rwsem);
3537         want_snap = mdsc->last_snap_seq;
3538         up_read(&mdsc->snap_rwsem);
3539
3540         dout("sync want tid %lld flush_seq %lld snap_seq %lld\n",
3541              want_tid, want_flush, want_snap);
3542
3543         wait_unsafe_requests(mdsc, want_tid);
3544         wait_caps_flush(mdsc, want_flush, want_snap);
3545 }
3546
3547 /*
3548  * true if all sessions are closed, or we force unmount
3549  */
3550 static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3551 {
3552         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3553                 return true;
3554         return atomic_read(&mdsc->num_sessions) == 0;
3555 }
3556
3557 /*
3558  * called after sb is ro.
3559  */
3560 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3561 {
3562         struct ceph_options *opts = mdsc->fsc->client->options;
3563         struct ceph_mds_session *session;
3564         int i;
3565
3566         dout("close_sessions\n");
3567
3568         /* close sessions */
3569         mutex_lock(&mdsc->mutex);
3570         for (i = 0; i < mdsc->max_sessions; i++) {
3571                 session = __ceph_lookup_mds_session(mdsc, i);
3572                 if (!session)
3573                         continue;
3574                 mutex_unlock(&mdsc->mutex);
3575                 mutex_lock(&session->s_mutex);
3576                 __close_session(mdsc, session);
3577                 mutex_unlock(&session->s_mutex);
3578                 ceph_put_mds_session(session);
3579                 mutex_lock(&mdsc->mutex);
3580         }
3581         mutex_unlock(&mdsc->mutex);
3582
3583         dout("waiting for sessions to close\n");
3584         wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3585                            ceph_timeout_jiffies(opts->mount_timeout));
3586
3587         /* tear down remaining sessions */
3588         mutex_lock(&mdsc->mutex);
3589         for (i = 0; i < mdsc->max_sessions; i++) {
3590                 if (mdsc->sessions[i]) {
3591                         session = get_session(mdsc->sessions[i]);
3592                         __unregister_session(mdsc, session);
3593                         mutex_unlock(&mdsc->mutex);
3594                         mutex_lock(&session->s_mutex);
3595                         remove_session_caps(session);
3596                         mutex_unlock(&session->s_mutex);
3597                         ceph_put_mds_session(session);
3598                         mutex_lock(&mdsc->mutex);
3599                 }
3600         }
3601         WARN_ON(!list_empty(&mdsc->cap_delay_list));
3602         mutex_unlock(&mdsc->mutex);
3603
3604         ceph_cleanup_empty_realms(mdsc);
3605
3606         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3607
3608         dout("stopped\n");
3609 }
3610
3611 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3612 {
3613         dout("stop\n");
3614         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3615         if (mdsc->mdsmap)
3616                 ceph_mdsmap_destroy(mdsc->mdsmap);
3617         kfree(mdsc->sessions);
3618         ceph_caps_finalize(mdsc);
3619         ceph_pool_perm_destroy(mdsc);
3620 }
3621
3622 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3623 {
3624         struct ceph_mds_client *mdsc = fsc->mdsc;
3625
3626         dout("mdsc_destroy %p\n", mdsc);
3627         ceph_mdsc_stop(mdsc);
3628
3629         /* flush out any connection work with references to us */
3630         ceph_msgr_flush();
3631
3632         fsc->mdsc = NULL;
3633         kfree(mdsc);
3634         dout("mdsc_destroy %p done\n", mdsc);
3635 }
3636
3637
3638 /*
3639  * handle mds map update.
3640  */
3641 void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3642 {
3643         u32 epoch;
3644         u32 maplen;
3645         void *p = msg->front.iov_base;
3646         void *end = p + msg->front.iov_len;
3647         struct ceph_mdsmap *newmap, *oldmap;
3648         struct ceph_fsid fsid;
3649         int err = -EINVAL;
3650
3651         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3652         ceph_decode_copy(&p, &fsid, sizeof(fsid));
3653         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3654                 return;
3655         epoch = ceph_decode_32(&p);
3656         maplen = ceph_decode_32(&p);
3657         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3658
3659         /* do we need it? */
3660         ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
3661         mutex_lock(&mdsc->mutex);
3662         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3663                 dout("handle_map epoch %u <= our %u\n",
3664                      epoch, mdsc->mdsmap->m_epoch);
3665                 mutex_unlock(&mdsc->mutex);
3666                 return;
3667         }
3668
3669         newmap = ceph_mdsmap_decode(&p, end);
3670         if (IS_ERR(newmap)) {
3671                 err = PTR_ERR(newmap);
3672                 goto bad_unlock;
3673         }
3674
3675         /* swap into place */
3676         if (mdsc->mdsmap) {
3677                 oldmap = mdsc->mdsmap;
3678                 mdsc->mdsmap = newmap;
3679                 check_new_map(mdsc, newmap, oldmap);
3680                 ceph_mdsmap_destroy(oldmap);
3681         } else {
3682                 mdsc->mdsmap = newmap;  /* first mds map */
3683         }
3684         mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3685
3686         __wake_requests(mdsc, &mdsc->waiting_for_map);
3687
3688         mutex_unlock(&mdsc->mutex);
3689         schedule_delayed(mdsc);
3690         return;
3691
3692 bad_unlock:
3693         mutex_unlock(&mdsc->mutex);
3694 bad:
3695         pr_err("error decoding mdsmap %d\n", err);
3696         return;
3697 }
3698
3699 static struct ceph_connection *con_get(struct ceph_connection *con)
3700 {
3701         struct ceph_mds_session *s = con->private;
3702
3703         if (get_session(s)) {
3704                 dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3705                 return con;
3706         }
3707         dout("mdsc con_get %p FAIL\n", s);
3708         return NULL;
3709 }
3710
3711 static void con_put(struct ceph_connection *con)
3712 {
3713         struct ceph_mds_session *s = con->private;
3714
3715         dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3716         ceph_put_mds_session(s);
3717 }
3718
3719 /*
3720  * if the client is unresponsive for long enough, the mds will kill
3721  * the session entirely.
3722  */
3723 static void peer_reset(struct ceph_connection *con)
3724 {
3725         struct ceph_mds_session *s = con->private;
3726         struct ceph_mds_client *mdsc = s->s_mdsc;
3727
3728         pr_warn("mds%d closed our session\n", s->s_mds);
3729         send_mds_reconnect(mdsc, s);
3730 }
3731
3732 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3733 {
3734         struct ceph_mds_session *s = con->private;
3735         struct ceph_mds_client *mdsc = s->s_mdsc;
3736         int type = le16_to_cpu(msg->hdr.type);
3737
3738         mutex_lock(&mdsc->mutex);
3739         if (__verify_registered_session(mdsc, s) < 0) {
3740                 mutex_unlock(&mdsc->mutex);
3741                 goto out;
3742         }
3743         mutex_unlock(&mdsc->mutex);
3744
3745         switch (type) {
3746         case CEPH_MSG_MDS_MAP:
3747                 ceph_mdsc_handle_map(mdsc, msg);
3748                 break;
3749         case CEPH_MSG_CLIENT_SESSION:
3750                 handle_session(s, msg);
3751                 break;
3752         case CEPH_MSG_CLIENT_REPLY:
3753                 handle_reply(s, msg);
3754                 break;
3755         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3756                 handle_forward(mdsc, s, msg);
3757                 break;
3758         case CEPH_MSG_CLIENT_CAPS:
3759                 ceph_handle_caps(s, msg);
3760                 break;
3761         case CEPH_MSG_CLIENT_SNAP:
3762                 ceph_handle_snap(mdsc, s, msg);
3763                 break;
3764         case CEPH_MSG_CLIENT_LEASE:
3765                 handle_lease(mdsc, s, msg);
3766                 break;
3767
3768         default:
3769                 pr_err("received unknown message type %d %s\n", type,
3770                        ceph_msg_type_name(type));
3771         }
3772 out:
3773         ceph_msg_put(msg);
3774 }
3775
3776 /*
3777  * authentication
3778  */
3779
3780 /*
3781  * Note: returned pointer is the address of a structure that's
3782  * managed separately.  Caller must *not* attempt to free it.
3783  */
3784 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3785                                         int *proto, int force_new)
3786 {
3787         struct ceph_mds_session *s = con->private;
3788         struct ceph_mds_client *mdsc = s->s_mdsc;
3789         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3790         struct ceph_auth_handshake *auth = &s->s_auth;
3791
3792         if (force_new && auth->authorizer) {
3793                 ceph_auth_destroy_authorizer(ac, auth->authorizer);
3794                 auth->authorizer = NULL;
3795         }
3796         if (!auth->authorizer) {
3797                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3798                                                       auth);
3799                 if (ret)
3800                         return ERR_PTR(ret);
3801         } else {
3802                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3803                                                       auth);
3804                 if (ret)
3805                         return ERR_PTR(ret);
3806         }
3807         *proto = ac->protocol;
3808
3809         return auth;
3810 }
3811
3812
3813 static int verify_authorizer_reply(struct ceph_connection *con, int len)
3814 {
3815         struct ceph_mds_session *s = con->private;
3816         struct ceph_mds_client *mdsc = s->s_mdsc;
3817         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3818
3819         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3820 }
3821
3822 static int invalidate_authorizer(struct ceph_connection *con)
3823 {
3824         struct ceph_mds_session *s = con->private;
3825         struct ceph_mds_client *mdsc = s->s_mdsc;
3826         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3827
3828         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3829
3830         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3831 }
3832
3833 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3834                                 struct ceph_msg_header *hdr, int *skip)
3835 {
3836         struct ceph_msg *msg;
3837         int type = (int) le16_to_cpu(hdr->type);
3838         int front_len = (int) le32_to_cpu(hdr->front_len);
3839
3840         if (con->in_msg)
3841                 return con->in_msg;
3842
3843         *skip = 0;
3844         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3845         if (!msg) {
3846                 pr_err("unable to allocate msg type %d len %d\n",
3847                        type, front_len);
3848                 return NULL;
3849         }
3850
3851         return msg;
3852 }
3853
3854 static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
3855 {
3856        struct ceph_mds_session *s = con->private;
3857        struct ceph_auth_handshake *auth = &s->s_auth;
3858        return ceph_auth_sign_message(auth, msg);
3859 }
3860
3861 static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
3862 {
3863        struct ceph_mds_session *s = con->private;
3864        struct ceph_auth_handshake *auth = &s->s_auth;
3865        return ceph_auth_check_message_signature(auth, msg);
3866 }
3867
3868 static const struct ceph_connection_operations mds_con_ops = {
3869         .get = con_get,
3870         .put = con_put,
3871         .dispatch = dispatch,
3872         .get_authorizer = get_authorizer,
3873         .verify_authorizer_reply = verify_authorizer_reply,
3874         .invalidate_authorizer = invalidate_authorizer,
3875         .peer_reset = peer_reset,
3876         .alloc_msg = mds_alloc_msg,
3877         .sign_message = sign_message,
3878         .check_message_signature = check_message_signature,
3879 };
3880
3881 /* eof */