fs/ceph/mds_client.c

   1 #include <linux/ceph/ceph_debug.h>
   2
   3 #include <linux/fs.h>
   4 #include <linux/wait.h>
   5 #include <linux/slab.h>
   6 #include <linux/gfp.h>
   7 #include <linux/sched.h>
   8 #include <linux/debugfs.h>
   9 #include <linux/seq_file.h>
  10 #include <linux/utsname.h>
  11 #include <linux/ratelimit.h>
  12
  13 #include "super.h"
  14 #include "mds_client.h"
  15
  16 #include <linux/ceph/ceph_features.h>
  17 #include <linux/ceph/messenger.h>
  18 #include <linux/ceph/decode.h>
  19 #include <linux/ceph/pagelist.h>
  20 #include <linux/ceph/auth.h>
  21 #include <linux/ceph/debugfs.h>
  22
  23 /*
  24  * A cluster of MDS (metadata server) daemons is responsible for
  25  * managing the file system namespace (the directory hierarchy and
  26  * inodes) and for coordinating shared access to storage.  Metadata is
  27  * partitioning hierarchically across a number of servers, and that
  28  * partition varies over time as the cluster adjusts the distribution
  29  * in order to balance load.
  30  *
  31  * The MDS client is primarily responsible to managing synchronous
  32  * metadata requests for operations like open, unlink, and so forth.
  33  * If there is a MDS failure, we find out about it when we (possibly
  34  * request and) receive a new MDS map, and can resubmit affected
  35  * requests.
  36  *
  37  * For the most part, though, we take advantage of a lossless
  38  * communications channel to the MDS, and do not need to worry about
  39  * timing out or resubmitting requests.
  40  *
  41  * We maintain a stateful "session" with each MDS we interact with.
  42  * Within each session, we sent periodic heartbeat messages to ensure
  43  * any capabilities or leases we have been issues remain valid.  If
  44  * the session times out and goes stale, our leases and capabilities
  45  * are no longer valid.
  46  */
  47
  48 struct ceph_reconnect_state {
  49         int nr_caps;
  50         struct ceph_pagelist *pagelist;
  51         bool flock;
  52 };
  53
  54 static void __wake_requests(struct ceph_mds_client *mdsc,
  55                             struct list_head *head);
  56
  57 static const struct ceph_connection_operations mds_con_ops;
  58
  59
  60 /*
  61  * mds reply parsing
  62  */
  63
  64 /*
  65  * parse individual inode info
  66  */
  67 static int parse_reply_info_in(void **p, void *end,
  68                                struct ceph_mds_reply_info_in *info,
  69                                u64 features)
  70 {
  71         int err = -EIO;
  72
  73         info->in = *p;
  74         *p += sizeof(struct ceph_mds_reply_inode) +
  75                 sizeof(*info->in->fragtree.splits) *
  76                 le32_to_cpu(info->in->fragtree.nsplits);
  77
  78         ceph_decode_32_safe(p, end, info->symlink_len, bad);
  79         ceph_decode_need(p, end, info->symlink_len, bad);
  80         info->symlink = *p;
  81         *p += info->symlink_len;
  82
  83         if (features & CEPH_FEATURE_DIRLAYOUTHASH)
  84                 ceph_decode_copy_safe(p, end, &info->dir_layout,
  85                                       sizeof(info->dir_layout), bad);
  86         else
  87                 memset(&info->dir_layout, 0, sizeof(info->dir_layout));
  88
  89         ceph_decode_32_safe(p, end, info->xattr_len, bad);
  90         ceph_decode_need(p, end, info->xattr_len, bad);
  91         info->xattr_data = *p;
  92         *p += info->xattr_len;
  93
  94         if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
  95                 ceph_decode_64_safe(p, end, info->inline_version, bad);
  96                 ceph_decode_32_safe(p, end, info->inline_len, bad);
  97                 ceph_decode_need(p, end, info->inline_len, bad);
  98                 info->inline_data = *p;
  99                 *p += info->inline_len;
 100         } else
 101                 info->inline_version = CEPH_INLINE_NONE;
 102
 103         if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 104                 ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 105                 ceph_decode_need(p, end, info->pool_ns_len, bad);
 106                 *p += info->pool_ns_len;
 107         } else {
 108                 info->pool_ns_len = 0;
 109         }
 110
 111         return 0;
 112 bad:
 113         return err;
 114 }
 115
 116 /*
 117  * parse a normal reply, which may contain a (dir+)dentry and/or a
 118  * target inode.
 119  */
 120 static int parse_reply_info_trace(void **p, void *end,
 121                                   struct ceph_mds_reply_info_parsed *info,
 122                                   u64 features)
 123 {
 124         int err;
 125
 126         if (info->head->is_dentry) {
 127                 err = parse_reply_info_in(p, end, &info->diri, features);
 128                 if (err < 0)
 129                         goto out_bad;
 130
 131                 if (unlikely(*p + sizeof(*info->dirfrag) > end))
 132                         goto bad;
 133                 info->dirfrag = *p;
 134                 *p += sizeof(*info->dirfrag) +
 135                         sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 136                 if (unlikely(*p > end))
 137                         goto bad;
 138
 139                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 140                 ceph_decode_need(p, end, info->dname_len, bad);
 141                 info->dname = *p;
 142                 *p += info->dname_len;
 143                 info->dlease = *p;
 144                 *p += sizeof(*info->dlease);
 145         }
 146
 147         if (info->head->is_target) {
 148                 err = parse_reply_info_in(p, end, &info->targeti, features);
 149                 if (err < 0)
 150                         goto out_bad;
 151         }
 152
 153         if (unlikely(*p != end))
 154                 goto bad;
 155         return 0;
 156
 157 bad:
 158         err = -EIO;
 159 out_bad:
 160         pr_err("problem parsing mds trace %d\n", err);
 161         return err;
 162 }
 163
 164 /*
 165  * parse readdir results
 166  */
 167 static int parse_reply_info_dir(void **p, void *end,
 168                                 struct ceph_mds_reply_info_parsed *info,
 169                                 u64 features)
 170 {
 171         u32 num, i = 0;
 172         int err;
 173
 174         info->dir_dir = *p;
 175         if (*p + sizeof(*info->dir_dir) > end)
 176                 goto bad;
 177         *p += sizeof(*info->dir_dir) +
 178                 sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 179         if (*p > end)
 180                 goto bad;
 181
 182         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 183         num = ceph_decode_32(p);
 184         info->dir_end = ceph_decode_8(p);
 185         info->dir_complete = ceph_decode_8(p);
 186         if (num == 0)
 187                 goto done;
 188
 189         BUG_ON(!info->dir_in);
 190         info->dir_dname = (void *)(info->dir_in + num);
 191         info->dir_dname_len = (void *)(info->dir_dname + num);
 192         info->dir_dlease = (void *)(info->dir_dname_len + num);
 193         if ((unsigned long)(info->dir_dlease + num) >
 194             (unsigned long)info->dir_in + info->dir_buf_size) {
 195                 pr_err("dir contents are larger than expected\n");
 196                 WARN_ON(1);
 197                 goto bad;
 198         }
 199
 200         info->dir_nr = num;
 201         while (num) {
 202                 /* dentry */
 203                 ceph_decode_need(p, end, sizeof(u32)*2, bad);
 204                 info->dir_dname_len[i] = ceph_decode_32(p);
 205                 ceph_decode_need(p, end, info->dir_dname_len[i], bad);
 206                 info->dir_dname[i] = *p;
 207                 *p += info->dir_dname_len[i];
 208                 dout("parsed dir dname '%.*s'\n", info->dir_dname_len[i],
 209                      info->dir_dname[i]);
 210                 info->dir_dlease[i] = *p;
 211                 *p += sizeof(struct ceph_mds_reply_lease);
 212
 213                 /* inode */
 214                 err = parse_reply_info_in(p, end, &info->dir_in[i], features);
 215                 if (err < 0)
 216                         goto out_bad;
 217                 i++;
 218                 num--;
 219         }
 220
 221 done:
 222         if (*p != end)
 223                 goto bad;
 224         return 0;
 225
 226 bad:
 227         err = -EIO;
 228 out_bad:
 229         pr_err("problem parsing dir contents %d\n", err);
 230         return err;
 231 }
 232
 233 /*
 234  * parse fcntl F_GETLK results
 235  */
 236 static int parse_reply_info_filelock(void **p, void *end,
 237                                      struct ceph_mds_reply_info_parsed *info,
 238                                      u64 features)
 239 {
 240         if (*p + sizeof(*info->filelock_reply) > end)
 241                 goto bad;
 242
 243         info->filelock_reply = *p;
 244         *p += sizeof(*info->filelock_reply);
 245
 246         if (unlikely(*p != end))
 247                 goto bad;
 248         return 0;
 249
 250 bad:
 251         return -EIO;
 252 }
 253
 254 /*
 255  * parse create results
 256  */
 257 static int parse_reply_info_create(void **p, void *end,
 258                                   struct ceph_mds_reply_info_parsed *info,
 259                                   u64 features)
 260 {
 261         if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 262                 if (*p == end) {
 263                         info->has_create_ino = false;
 264                 } else {
 265                         info->has_create_ino = true;
 266                         info->ino = ceph_decode_64(p);
 267                 }
 268         }
 269
 270         if (unlikely(*p != end))
 271                 goto bad;
 272         return 0;
 273
 274 bad:
 275         return -EIO;
 276 }
 277
 278 /*
 279  * parse extra results
 280  */
 281 static int parse_reply_info_extra(void **p, void *end,
 282                                   struct ceph_mds_reply_info_parsed *info,
 283                                   u64 features)
 284 {
 285         if (info->head->op == CEPH_MDS_OP_GETFILELOCK)
 286                 return parse_reply_info_filelock(p, end, info, features);
 287         else if (info->head->op == CEPH_MDS_OP_READDIR ||
 288                  info->head->op == CEPH_MDS_OP_LSSNAP)
 289                 return parse_reply_info_dir(p, end, info, features);
 290         else if (info->head->op == CEPH_MDS_OP_CREATE)
 291                 return parse_reply_info_create(p, end, info, features);
 292         else
 293                 return -EIO;
 294 }
 295
 296 /*
 297  * parse entire mds reply
 298  */
 299 static int parse_reply_info(struct ceph_msg *msg,
 300                             struct ceph_mds_reply_info_parsed *info,
 301                             u64 features)
 302 {
 303         void *p, *end;
 304         u32 len;
 305         int err;
 306
 307         info->head = msg->front.iov_base;
 308         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 309         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 310
 311         /* trace */
 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_trace(&p, p+len, info, features);
 316                 if (err < 0)
 317                         goto out_bad;
 318         }
 319
 320         /* extra */
 321         ceph_decode_32_safe(&p, end, len, bad);
 322         if (len > 0) {
 323                 ceph_decode_need(&p, end, len, bad);
 324                 err = parse_reply_info_extra(&p, p+len, info, features);
 325                 if (err < 0)
 326                         goto out_bad;
 327         }
 328
 329         /* snap blob */
 330         ceph_decode_32_safe(&p, end, len, bad);
 331         info->snapblob_len = len;
 332         info->snapblob = p;
 333         p += len;
 334
 335         if (p != end)
 336                 goto bad;
 337         return 0;
 338
 339 bad:
 340         err = -EIO;
 341 out_bad:
 342         pr_err("mds parse_reply err %d\n", err);
 343         return err;
 344 }
 345
 346 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 347 {
 348         if (!info->dir_in)
 349                 return;
 350         free_pages((unsigned long)info->dir_in, get_order(info->dir_buf_size));
 351 }
 352
 353
 354 /*
 355  * sessions
 356  */
 357 const char *ceph_session_state_name(int s)
 358 {
 359         switch (s) {
 360         case CEPH_MDS_SESSION_NEW: return "new";
 361         case CEPH_MDS_SESSION_OPENING: return "opening";
 362         case CEPH_MDS_SESSION_OPEN: return "open";
 363         case CEPH_MDS_SESSION_HUNG: return "hung";
 364         case CEPH_MDS_SESSION_CLOSING: return "closing";
 365         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 366         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 367         default: return "???";
 368         }
 369 }
 370
 371 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 372 {
 373         if (atomic_inc_not_zero(&s->s_ref)) {
 374                 dout("mdsc get_session %p %d -> %d\n", s,
 375                      atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
 376                 return s;
 377         } else {
 378                 dout("mdsc get_session %p 0 -- FAIL", s);
 379                 return NULL;
 380         }
 381 }
 382
 383 void ceph_put_mds_session(struct ceph_mds_session *s)
 384 {
 385         dout("mdsc put_session %p %d -> %d\n", s,
 386              atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
 387         if (atomic_dec_and_test(&s->s_ref)) {
 388                 if (s->s_auth.authorizer)
 389                         ceph_auth_destroy_authorizer(
 390                                 s->s_mdsc->fsc->client->monc.auth,
 391                                 s->s_auth.authorizer);
 392                 kfree(s);
 393         }
 394 }
 395
 396 /*
 397  * called under mdsc->mutex
 398  */
 399 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 400                                                    int mds)
 401 {
 402         struct ceph_mds_session *session;
 403
 404         if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
 405                 return NULL;
 406         session = mdsc->sessions[mds];
 407         dout("lookup_mds_session %p %d\n", session,
 408              atomic_read(&session->s_ref));
 409         get_session(session);
 410         return session;
 411 }
 412
 413 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 414 {
 415         if (mds >= mdsc->max_sessions)
 416                 return false;
 417         return mdsc->sessions[mds];
 418 }
 419
 420 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 421                                        struct ceph_mds_session *s)
 422 {
 423         if (s->s_mds >= mdsc->max_sessions ||
 424             mdsc->sessions[s->s_mds] != s)
 425                 return -ENOENT;
 426         return 0;
 427 }
 428
 429 /*
 430  * create+register a new session for given mds.
 431  * called under mdsc->mutex.
 432  */
 433 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 434                                                  int mds)
 435 {
 436         struct ceph_mds_session *s;
 437
 438         if (mds >= mdsc->mdsmap->m_max_mds)
 439                 return ERR_PTR(-EINVAL);
 440
 441         s = kzalloc(sizeof(*s), GFP_NOFS);
 442         if (!s)
 443                 return ERR_PTR(-ENOMEM);
 444         s->s_mdsc = mdsc;
 445         s->s_mds = mds;
 446         s->s_state = CEPH_MDS_SESSION_NEW;
 447         s->s_ttl = 0;
 448         s->s_seq = 0;
 449         mutex_init(&s->s_mutex);
 450
 451         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 452
 453         spin_lock_init(&s->s_gen_ttl_lock);
 454         s->s_cap_gen = 0;
 455         s->s_cap_ttl = jiffies - 1;
 456
 457         spin_lock_init(&s->s_cap_lock);
 458         s->s_renew_requested = 0;
 459         s->s_renew_seq = 0;
 460         INIT_LIST_HEAD(&s->s_caps);
 461         s->s_nr_caps = 0;
 462         s->s_trim_caps = 0;
 463         atomic_set(&s->s_ref, 1);
 464         INIT_LIST_HEAD(&s->s_waiting);
 465         INIT_LIST_HEAD(&s->s_unsafe);
 466         s->s_num_cap_releases = 0;
 467         s->s_cap_reconnect = 0;
 468         s->s_cap_iterator = NULL;
 469         INIT_LIST_HEAD(&s->s_cap_releases);
 470         INIT_LIST_HEAD(&s->s_cap_flushing);
 471         INIT_LIST_HEAD(&s->s_cap_snaps_flushing);
 472
 473         dout("register_session mds%d\n", mds);
 474         if (mds >= mdsc->max_sessions) {
 475                 int newmax = 1 << get_count_order(mds+1);
 476                 struct ceph_mds_session **sa;
 477
 478                 dout("register_session realloc to %d\n", newmax);
 479                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 480                 if (sa == NULL)
 481                         goto fail_realloc;
 482                 if (mdsc->sessions) {
 483                         memcpy(sa, mdsc->sessions,
 484                                mdsc->max_sessions * sizeof(void *));
 485                         kfree(mdsc->sessions);
 486                 }
 487                 mdsc->sessions = sa;
 488                 mdsc->max_sessions = newmax;
 489         }
 490         mdsc->sessions[mds] = s;
 491         atomic_inc(&mdsc->num_sessions);
 492         atomic_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 493
 494         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 495                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 496
 497         return s;
 498
 499 fail_realloc:
 500         kfree(s);
 501         return ERR_PTR(-ENOMEM);
 502 }
 503
 504 /*
 505  * called under mdsc->mutex
 506  */
 507 static void __unregister_session(struct ceph_mds_client *mdsc,
 508                                struct ceph_mds_session *s)
 509 {
 510         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 511         BUG_ON(mdsc->sessions[s->s_mds] != s);
 512         mdsc->sessions[s->s_mds] = NULL;
 513         ceph_con_close(&s->s_con);
 514         ceph_put_mds_session(s);
 515         atomic_dec(&mdsc->num_sessions);
 516 }
 517
 518 /*
 519  * drop session refs in request.
 520  *
 521  * should be last request ref, or hold mdsc->mutex
 522  */
 523 static void put_request_session(struct ceph_mds_request *req)
 524 {
 525         if (req->r_session) {
 526                 ceph_put_mds_session(req->r_session);
 527                 req->r_session = NULL;
 528         }
 529 }
 530
 531 void ceph_mdsc_release_request(struct kref *kref)
 532 {
 533         struct ceph_mds_request *req = container_of(kref,
 534                                                     struct ceph_mds_request,
 535                                                     r_kref);
 536         destroy_reply_info(&req->r_reply_info);
 537         if (req->r_request)
 538                 ceph_msg_put(req->r_request);
 539         if (req->r_reply)
 540                 ceph_msg_put(req->r_reply);
 541         if (req->r_inode) {
 542                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 543                 iput(req->r_inode);
 544         }
 545         if (req->r_locked_dir)
 546                 ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
 547         iput(req->r_target_inode);
 548         if (req->r_dentry)
 549                 dput(req->r_dentry);
 550         if (req->r_old_dentry)
 551                 dput(req->r_old_dentry);
 552         if (req->r_old_dentry_dir) {
 553                 /*
 554                  * track (and drop pins for) r_old_dentry_dir
 555                  * separately, since r_old_dentry's d_parent may have
 556                  * changed between the dir mutex being dropped and
 557                  * this request being freed.
 558                  */
 559                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 560                                   CEPH_CAP_PIN);
 561                 iput(req->r_old_dentry_dir);
 562         }
 563         kfree(req->r_path1);
 564         kfree(req->r_path2);
 565         if (req->r_pagelist)
 566                 ceph_pagelist_release(req->r_pagelist);
 567         put_request_session(req);
 568         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 569         kfree(req);
 570 }
 571
 572 /*
 573  * lookup session, bump ref if found.
 574  *
 575  * called under mdsc->mutex.
 576  */
 577 static struct ceph_mds_request *__lookup_request(struct ceph_mds_client *mdsc,
 578                                              u64 tid)
 579 {
 580         struct ceph_mds_request *req;
 581         struct rb_node *n = mdsc->request_tree.rb_node;
 582
 583         while (n) {
 584                 req = rb_entry(n, struct ceph_mds_request, r_node);
 585                 if (tid < req->r_tid)
 586                         n = n->rb_left;
 587                 else if (tid > req->r_tid)
 588                         n = n->rb_right;
 589                 else {
 590                         ceph_mdsc_get_request(req);
 591                         return req;
 592                 }
 593         }
 594         return NULL;
 595 }
 596
 597 static void __insert_request(struct ceph_mds_client *mdsc,
 598                              struct ceph_mds_request *new)
 599 {
 600         struct rb_node **p = &mdsc->request_tree.rb_node;
 601         struct rb_node *parent = NULL;
 602         struct ceph_mds_request *req = NULL;
 603
 604         while (*p) {
 605                 parent = *p;
 606                 req = rb_entry(parent, struct ceph_mds_request, r_node);
 607                 if (new->r_tid < req->r_tid)
 608                         p = &(*p)->rb_left;
 609                 else if (new->r_tid > req->r_tid)
 610                         p = &(*p)->rb_right;
 611                 else
 612                         BUG();
 613         }
 614
 615         rb_link_node(&new->r_node, parent, p);
 616         rb_insert_color(&new->r_node, &mdsc->request_tree);
 617 }
 618
 619 /*
 620  * Register an in-flight request, and assign a tid.  Link to directory
 621  * are modifying (if any).
 622  *
 623  * Called under mdsc->mutex.
 624  */
 625 static void __register_request(struct ceph_mds_client *mdsc,
 626                                struct ceph_mds_request *req,
 627                                struct inode *dir)
 628 {
 629         req->r_tid = ++mdsc->last_tid;
 630         if (req->r_num_caps)
 631                 ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 632                                   req->r_num_caps);
 633         dout("__register_request %p tid %lld\n", req, req->r_tid);
 634         ceph_mdsc_get_request(req);
 635         __insert_request(mdsc, req);
 636
 637         req->r_uid = current_fsuid();
 638         req->r_gid = current_fsgid();
 639
 640         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 641                 mdsc->oldest_tid = req->r_tid;
 642
 643         if (dir) {
 644                 ihold(dir);
 645                 req->r_unsafe_dir = dir;
 646         }
 647 }
 648
 649 static void __unregister_request(struct ceph_mds_client *mdsc,
 650                                  struct ceph_mds_request *req)
 651 {
 652         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 653
 654         if (req->r_tid == mdsc->oldest_tid) {
 655                 struct rb_node *p = rb_next(&req->r_node);
 656                 mdsc->oldest_tid = 0;
 657                 while (p) {
 658                         struct ceph_mds_request *next_req =
 659                                 rb_entry(p, struct ceph_mds_request, r_node);
 660                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 661                                 mdsc->oldest_tid = next_req->r_tid;
 662                                 break;
 663                         }
 664                         p = rb_next(p);
 665                 }
 666         }
 667
 668         rb_erase(&req->r_node, &mdsc->request_tree);
 669         RB_CLEAR_NODE(&req->r_node);
 670
 671         if (req->r_unsafe_dir && req->r_got_unsafe) {
 672                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 673                 spin_lock(&ci->i_unsafe_lock);
 674                 list_del_init(&req->r_unsafe_dir_item);
 675                 spin_unlock(&ci->i_unsafe_lock);
 676         }
 677         if (req->r_target_inode && req->r_got_unsafe) {
 678                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 679                 spin_lock(&ci->i_unsafe_lock);
 680                 list_del_init(&req->r_unsafe_target_item);
 681                 spin_unlock(&ci->i_unsafe_lock);
 682         }
 683
 684         if (req->r_unsafe_dir) {
 685                 iput(req->r_unsafe_dir);
 686                 req->r_unsafe_dir = NULL;
 687         }
 688
 689         complete_all(&req->r_safe_completion);
 690
 691         ceph_mdsc_put_request(req);
 692 }
 693
 694 /*
 695  * Choose mds to send request to next.  If there is a hint set in the
 696  * request (e.g., due to a prior forward hint from the mds), use that.
 697  * Otherwise, consult frag tree and/or caps to identify the
 698  * appropriate mds.  If all else fails, choose randomly.
 699  *
 700  * Called under mdsc->mutex.
 701  */
 702 static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 703 {
 704         /*
 705          * we don't need to worry about protecting the d_parent access
 706          * here because we never renaming inside the snapped namespace
 707          * except to resplice to another snapdir, and either the old or new
 708          * result is a valid result.
 709          */
 710         while (!IS_ROOT(dentry) && ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
 711                 dentry = dentry->d_parent;
 712         return dentry;
 713 }
 714
 715 static int __choose_mds(struct ceph_mds_client *mdsc,
 716                         struct ceph_mds_request *req)
 717 {
 718         struct inode *inode;
 719         struct ceph_inode_info *ci;
 720         struct ceph_cap *cap;
 721         int mode = req->r_direct_mode;
 722         int mds = -1;
 723         u32 hash = req->r_direct_hash;
 724         bool is_hash = req->r_direct_is_hash;
 725
 726         /*
 727          * is there a specific mds we should try?  ignore hint if we have
 728          * no session and the mds is not up (active or recovering).
 729          */
 730         if (req->r_resend_mds >= 0 &&
 731             (__have_session(mdsc, req->r_resend_mds) ||
 732              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 733                 dout("choose_mds using resend_mds mds%d\n",
 734                      req->r_resend_mds);
 735                 return req->r_resend_mds;
 736         }
 737
 738         if (mode == USE_RANDOM_MDS)
 739                 goto random;
 740
 741         inode = NULL;
 742         if (req->r_inode) {
 743                 inode = req->r_inode;
 744         } else if (req->r_dentry) {
 745                 /* ignore race with rename; old or new d_parent is okay */
 746                 struct dentry *parent = req->r_dentry->d_parent;
 747                 struct inode *dir = d_inode(parent);
 748
 749                 if (dir->i_sb != mdsc->fsc->sb) {
 750                         /* not this fs! */
 751                         inode = d_inode(req->r_dentry);
 752                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 753                         /* direct snapped/virtual snapdir requests
 754                          * based on parent dir inode */
 755                         struct dentry *dn = get_nonsnap_parent(parent);
 756                         inode = d_inode(dn);
 757                         dout("__choose_mds using nonsnap parent %p\n", inode);
 758                 } else {
 759                         /* dentry target */
 760                         inode = d_inode(req->r_dentry);
 761                         if (!inode || mode == USE_AUTH_MDS) {
 762                                 /* dir + name */
 763                                 inode = dir;
 764                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 765                                 is_hash = true;
 766                         }
 767                 }
 768         }
 769
 770         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 771              (int)hash, mode);
 772         if (!inode)
 773                 goto random;
 774         ci = ceph_inode(inode);
 775
 776         if (is_hash && S_ISDIR(inode->i_mode)) {
 777                 struct ceph_inode_frag frag;
 778                 int found;
 779
 780                 ceph_choose_frag(ci, hash, &frag, &found);
 781                 if (found) {
 782                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 783                                 u8 r;
 784
 785                                 /* choose a random replica */
 786                                 get_random_bytes(&r, 1);
 787                                 r %= frag.ndist;
 788                                 mds = frag.dist[r];
 789                                 dout("choose_mds %p %llx.%llx "
 790                                      "frag %u mds%d (%d/%d)\n",
 791                                      inode, ceph_vinop(inode),
 792                                      frag.frag, mds,
 793                                      (int)r, frag.ndist);
 794                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 795                                     CEPH_MDS_STATE_ACTIVE)
 796                                         return mds;
 797                         }
 798
 799                         /* since this file/dir wasn't known to be
 800                          * replicated, then we want to look for the
 801                          * authoritative mds. */
 802                         mode = USE_AUTH_MDS;
 803                         if (frag.mds >= 0) {
 804                                 /* choose auth mds */
 805                                 mds = frag.mds;
 806                                 dout("choose_mds %p %llx.%llx "
 807                                      "frag %u mds%d (auth)\n",
 808                                      inode, ceph_vinop(inode), frag.frag, mds);
 809                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 810                                     CEPH_MDS_STATE_ACTIVE)
 811                                         return mds;
 812                         }
 813                 }
 814         }
 815
 816         spin_lock(&ci->i_ceph_lock);
 817         cap = NULL;
 818         if (mode == USE_AUTH_MDS)
 819                 cap = ci->i_auth_cap;
 820         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 821                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 822         if (!cap) {
 823                 spin_unlock(&ci->i_ceph_lock);
 824                 goto random;
 825         }
 826         mds = cap->session->s_mds;
 827         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 828              inode, ceph_vinop(inode), mds,
 829              cap == ci->i_auth_cap ? "auth " : "", cap);
 830         spin_unlock(&ci->i_ceph_lock);
 831         return mds;
 832
 833 random:
 834         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 835         dout("choose_mds chose random mds%d\n", mds);
 836         return mds;
 837 }
 838
 839
 840 /*
 841  * session messages
 842  */
 843 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 844 {
 845         struct ceph_msg *msg;
 846         struct ceph_mds_session_head *h;
 847
 848         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 849                            false);
 850         if (!msg) {
 851                 pr_err("create_session_msg ENOMEM creating msg\n");
 852                 return NULL;
 853         }
 854         h = msg->front.iov_base;
 855         h->op = cpu_to_le32(op);
 856         h->seq = cpu_to_le64(seq);
 857
 858         return msg;
 859 }
 860
 861 /*
 862  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
 863  * to include additional client metadata fields.
 864  */
 865 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
 866 {
 867         struct ceph_msg *msg;
 868         struct ceph_mds_session_head *h;
 869         int i = -1;
 870         int metadata_bytes = 0;
 871         int metadata_key_count = 0;
 872         struct ceph_options *opt = mdsc->fsc->client->options;
 873         void *p;
 874
 875         const char* metadata[][2] = {
 876                 {"hostname", utsname()->nodename},
 877                 {"kernel_version", utsname()->release},
 878                 {"entity_id", opt->name ? opt->name : ""},
 879                 {NULL, NULL}
 880         };
 881
 882         /* Calculate serialized length of metadata */
 883         metadata_bytes = 4;  /* map length */
 884         for (i = 0; metadata[i][0] != NULL; ++i) {
 885                 metadata_bytes += 8 + strlen(metadata[i][0]) +
 886                         strlen(metadata[i][1]);
 887                 metadata_key_count++;
 888         }
 889
 890         /* Allocate the message */
 891         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + metadata_bytes,
 892                            GFP_NOFS, false);
 893         if (!msg) {
 894                 pr_err("create_session_msg ENOMEM creating msg\n");
 895                 return NULL;
 896         }
 897         h = msg->front.iov_base;
 898         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 899         h->seq = cpu_to_le64(seq);
 900
 901         /*
 902          * Serialize client metadata into waiting buffer space, using
 903          * the format that userspace expects for map<string, string>
 904          *
 905          * ClientSession messages with metadata are v2
 906          */
 907         msg->hdr.version = cpu_to_le16(2);
 908         msg->hdr.compat_version = cpu_to_le16(1);
 909
 910         /* The write pointer, following the session_head structure */
 911         p = msg->front.iov_base + sizeof(*h);
 912
 913         /* Number of entries in the map */
 914         ceph_encode_32(&p, metadata_key_count);
 915
 916         /* Two length-prefixed strings for each entry in the map */
 917         for (i = 0; metadata[i][0] != NULL; ++i) {
 918                 size_t const key_len = strlen(metadata[i][0]);
 919                 size_t const val_len = strlen(metadata[i][1]);
 920
 921                 ceph_encode_32(&p, key_len);
 922                 memcpy(p, metadata[i][0], key_len);
 923                 p += key_len;
 924                 ceph_encode_32(&p, val_len);
 925                 memcpy(p, metadata[i][1], val_len);
 926                 p += val_len;
 927         }
 928
 929         return msg;
 930 }
 931
 932 /*
 933  * send session open request.
 934  *
 935  * called under mdsc->mutex
 936  */
 937 static int __open_session(struct ceph_mds_client *mdsc,
 938                           struct ceph_mds_session *session)
 939 {
 940         struct ceph_msg *msg;
 941         int mstate;
 942         int mds = session->s_mds;
 943
 944         /* wait for mds to go active? */
 945         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 946         dout("open_session to mds%d (%s)\n", mds,
 947              ceph_mds_state_name(mstate));
 948         session->s_state = CEPH_MDS_SESSION_OPENING;
 949         session->s_renew_requested = jiffies;
 950
 951         /* send connect message */
 952         msg = create_session_open_msg(mdsc, session->s_seq);
 953         if (!msg)
 954                 return -ENOMEM;
 955         ceph_con_send(&session->s_con, msg);
 956         return 0;
 957 }
 958
 959 /*
 960  * open sessions for any export targets for the given mds
 961  *
 962  * called under mdsc->mutex
 963  */
 964 static struct ceph_mds_session *
 965 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
 966 {
 967         struct ceph_mds_session *session;
 968
 969         session = __ceph_lookup_mds_session(mdsc, target);
 970         if (!session) {
 971                 session = register_session(mdsc, target);
 972                 if (IS_ERR(session))
 973                         return session;
 974         }
 975         if (session->s_state == CEPH_MDS_SESSION_NEW ||
 976             session->s_state == CEPH_MDS_SESSION_CLOSING)
 977                 __open_session(mdsc, session);
 978
 979         return session;
 980 }
 981
 982 struct ceph_mds_session *
 983 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
 984 {
 985         struct ceph_mds_session *session;
 986
 987         dout("open_export_target_session to mds%d\n", target);
 988
 989         mutex_lock(&mdsc->mutex);
 990         session = __open_export_target_session(mdsc, target);
 991         mutex_unlock(&mdsc->mutex);
 992
 993         return session;
 994 }
 995
 996 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 997                                           struct ceph_mds_session *session)
 998 {
 999         struct ceph_mds_info *mi;
1000         struct ceph_mds_session *ts;
1001         int i, mds = session->s_mds;
1002
1003         if (mds >= mdsc->mdsmap->m_max_mds)
1004                 return;
1005
1006         mi = &mdsc->mdsmap->m_info[mds];
1007         dout("open_export_target_sessions for mds%d (%d targets)\n",
1008              session->s_mds, mi->num_export_targets);
1009
1010         for (i = 0; i < mi->num_export_targets; i++) {
1011                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1012                 if (!IS_ERR(ts))
1013                         ceph_put_mds_session(ts);
1014         }
1015 }
1016
1017 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1018                                            struct ceph_mds_session *session)
1019 {
1020         mutex_lock(&mdsc->mutex);
1021         __open_export_target_sessions(mdsc, session);
1022         mutex_unlock(&mdsc->mutex);
1023 }
1024
1025 /*
1026  * session caps
1027  */
1028
1029 /* caller holds s_cap_lock, we drop it */
1030 static void cleanup_cap_releases(struct ceph_mds_client *mdsc,
1031                                  struct ceph_mds_session *session)
1032         __releases(session->s_cap_lock)
1033 {
1034         LIST_HEAD(tmp_list);
1035         list_splice_init(&session->s_cap_releases, &tmp_list);
1036         session->s_num_cap_releases = 0;
1037         spin_unlock(&session->s_cap_lock);
1038
1039         dout("cleanup_cap_releases mds%d\n", session->s_mds);
1040         while (!list_empty(&tmp_list)) {
1041                 struct ceph_cap *cap;
1042                 /* zero out the in-progress message */
1043                 cap = list_first_entry(&tmp_list,
1044                                         struct ceph_cap, session_caps);
1045                 list_del(&cap->session_caps);
1046                 ceph_put_cap(mdsc, cap);
1047         }
1048 }
1049
1050 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1051                                      struct ceph_mds_session *session)
1052 {
1053         struct ceph_mds_request *req;
1054         struct rb_node *p;
1055
1056         dout("cleanup_session_requests mds%d\n", session->s_mds);
1057         mutex_lock(&mdsc->mutex);
1058         while (!list_empty(&session->s_unsafe)) {
1059                 req = list_first_entry(&session->s_unsafe,
1060                                        struct ceph_mds_request, r_unsafe_item);
1061                 list_del_init(&req->r_unsafe_item);
1062                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1063                                     req->r_tid);
1064                 __unregister_request(mdsc, req);
1065         }
1066         /* zero r_attempts, so kick_requests() will re-send requests */
1067         p = rb_first(&mdsc->request_tree);
1068         while (p) {
1069                 req = rb_entry(p, struct ceph_mds_request, r_node);
1070                 p = rb_next(p);
1071                 if (req->r_session &&
1072                     req->r_session->s_mds == session->s_mds)
1073                         req->r_attempts = 0;
1074         }
1075         mutex_unlock(&mdsc->mutex);
1076 }
1077
1078 /*
1079  * Helper to safely iterate over all caps associated with a session, with
1080  * special care taken to handle a racing __ceph_remove_cap().
1081  *
1082  * Caller must hold session s_mutex.
1083  */
1084 static int iterate_session_caps(struct ceph_mds_session *session,
1085                                  int (*cb)(struct inode *, struct ceph_cap *,
1086                                             void *), void *arg)
1087 {
1088         struct list_head *p;
1089         struct ceph_cap *cap;
1090         struct inode *inode, *last_inode = NULL;
1091         struct ceph_cap *old_cap = NULL;
1092         int ret;
1093
1094         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1095         spin_lock(&session->s_cap_lock);
1096         p = session->s_caps.next;
1097         while (p != &session->s_caps) {
1098                 cap = list_entry(p, struct ceph_cap, session_caps);
1099                 inode = igrab(&cap->ci->vfs_inode);
1100                 if (!inode) {
1101                         p = p->next;
1102                         continue;
1103                 }
1104                 session->s_cap_iterator = cap;
1105                 spin_unlock(&session->s_cap_lock);
1106
1107                 if (last_inode) {
1108                         iput(last_inode);
1109                         last_inode = NULL;
1110                 }
1111                 if (old_cap) {
1112                         ceph_put_cap(session->s_mdsc, old_cap);
1113                         old_cap = NULL;
1114                 }
1115
1116                 ret = cb(inode, cap, arg);
1117                 last_inode = inode;
1118
1119                 spin_lock(&session->s_cap_lock);
1120                 p = p->next;
1121                 if (cap->ci == NULL) {
1122                         dout("iterate_session_caps  finishing cap %p removal\n",
1123                              cap);
1124                         BUG_ON(cap->session != session);
1125                         cap->session = NULL;
1126                         list_del_init(&cap->session_caps);
1127                         session->s_nr_caps--;
1128                         if (cap->queue_release) {
1129                                 list_add_tail(&cap->session_caps,
1130                                               &session->s_cap_releases);
1131                                 session->s_num_cap_releases++;
1132                         } else {
1133                                 old_cap = cap;  /* put_cap it w/o locks held */
1134                         }
1135                 }
1136                 if (ret < 0)
1137                         goto out;
1138         }
1139         ret = 0;
1140 out:
1141         session->s_cap_iterator = NULL;
1142         spin_unlock(&session->s_cap_lock);
1143
1144         iput(last_inode);
1145         if (old_cap)
1146                 ceph_put_cap(session->s_mdsc, old_cap);
1147
1148         return ret;
1149 }
1150
1151 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1152                                   void *arg)
1153 {
1154         struct ceph_inode_info *ci = ceph_inode(inode);
1155         LIST_HEAD(to_remove);
1156         int drop = 0;
1157
1158         dout("removing cap %p, ci is %p, inode is %p\n",
1159              cap, ci, &ci->vfs_inode);
1160         spin_lock(&ci->i_ceph_lock);
1161         __ceph_remove_cap(cap, false);
1162         if (!ci->i_auth_cap) {
1163                 struct ceph_cap_flush *cf;
1164                 struct ceph_mds_client *mdsc =
1165                         ceph_sb_to_client(inode->i_sb)->mdsc;
1166
1167                 while (true) {
1168                         struct rb_node *n = rb_first(&ci->i_cap_flush_tree);
1169                         if (!n)
1170                                 break;
1171                         cf = rb_entry(n, struct ceph_cap_flush, i_node);
1172                         rb_erase(&cf->i_node, &ci->i_cap_flush_tree);
1173                         list_add(&cf->list, &to_remove);
1174                 }
1175
1176                 spin_lock(&mdsc->cap_dirty_lock);
1177
1178                 list_for_each_entry(cf, &to_remove, list)
1179                         rb_erase(&cf->g_node, &mdsc->cap_flush_tree);
1180
1181                 if (!list_empty(&ci->i_dirty_item)) {
1182                         pr_warn_ratelimited(
1183                                 " dropping dirty %s state for %p %lld\n",
1184                                 ceph_cap_string(ci->i_dirty_caps),
1185                                 inode, ceph_ino(inode));
1186                         ci->i_dirty_caps = 0;
1187                         list_del_init(&ci->i_dirty_item);
1188                         drop = 1;
1189                 }
1190                 if (!list_empty(&ci->i_flushing_item)) {
1191                         pr_warn_ratelimited(
1192                                 " dropping dirty+flushing %s state for %p %lld\n",
1193                                 ceph_cap_string(ci->i_flushing_caps),
1194                                 inode, ceph_ino(inode));
1195                         ci->i_flushing_caps = 0;
1196                         list_del_init(&ci->i_flushing_item);
1197                         mdsc->num_cap_flushing--;
1198                         drop = 1;
1199                 }
1200                 spin_unlock(&mdsc->cap_dirty_lock);
1201
1202                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1203                         list_add(&ci->i_prealloc_cap_flush->list, &to_remove);
1204                         ci->i_prealloc_cap_flush = NULL;
1205                 }
1206         }
1207         spin_unlock(&ci->i_ceph_lock);
1208         while (!list_empty(&to_remove)) {
1209                 struct ceph_cap_flush *cf;
1210                 cf = list_first_entry(&to_remove,
1211                                       struct ceph_cap_flush, list);
1212                 list_del(&cf->list);
1213                 ceph_free_cap_flush(cf);
1214         }
1215         while (drop--)
1216                 iput(inode);
1217         return 0;
1218 }
1219
1220 /*
1221  * caller must hold session s_mutex
1222  */
1223 static void remove_session_caps(struct ceph_mds_session *session)
1224 {
1225         dout("remove_session_caps on %p\n", session);
1226         iterate_session_caps(session, remove_session_caps_cb, NULL);
1227
1228         spin_lock(&session->s_cap_lock);
1229         if (session->s_nr_caps > 0) {
1230                 struct super_block *sb = session->s_mdsc->fsc->sb;
1231                 struct inode *inode;
1232                 struct ceph_cap *cap, *prev = NULL;
1233                 struct ceph_vino vino;
1234                 /*
1235                  * iterate_session_caps() skips inodes that are being
1236                  * deleted, we need to wait until deletions are complete.
1237                  * __wait_on_freeing_inode() is designed for the job,
1238                  * but it is not exported, so use lookup inode function
1239                  * to access it.
1240                  */
1241                 while (!list_empty(&session->s_caps)) {
1242                         cap = list_entry(session->s_caps.next,
1243                                          struct ceph_cap, session_caps);
1244                         if (cap == prev)
1245                                 break;
1246                         prev = cap;
1247                         vino = cap->ci->i_vino;
1248                         spin_unlock(&session->s_cap_lock);
1249
1250                         inode = ceph_find_inode(sb, vino);
1251                         iput(inode);
1252
1253                         spin_lock(&session->s_cap_lock);
1254                 }
1255         }
1256
1257         // drop cap expires and unlock s_cap_lock
1258         cleanup_cap_releases(session->s_mdsc, session);
1259
1260         BUG_ON(session->s_nr_caps > 0);
1261         BUG_ON(!list_empty(&session->s_cap_flushing));
1262 }
1263
1264 /*
1265  * wake up any threads waiting on this session's caps.  if the cap is
1266  * old (didn't get renewed on the client reconnect), remove it now.
1267  *
1268  * caller must hold s_mutex.
1269  */
1270 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1271                               void *arg)
1272 {
1273         struct ceph_inode_info *ci = ceph_inode(inode);
1274
1275         wake_up_all(&ci->i_cap_wq);
1276         if (arg) {
1277                 spin_lock(&ci->i_ceph_lock);
1278                 ci->i_wanted_max_size = 0;
1279                 ci->i_requested_max_size = 0;
1280                 spin_unlock(&ci->i_ceph_lock);
1281         }
1282         return 0;
1283 }
1284
1285 static void wake_up_session_caps(struct ceph_mds_session *session,
1286                                  int reconnect)
1287 {
1288         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1289         iterate_session_caps(session, wake_up_session_cb,
1290                              (void *)(unsigned long)reconnect);
1291 }
1292
1293 /*
1294  * Send periodic message to MDS renewing all currently held caps.  The
1295  * ack will reset the expiration for all caps from this session.
1296  *
1297  * caller holds s_mutex
1298  */
1299 static int send_renew_caps(struct ceph_mds_client *mdsc,
1300                            struct ceph_mds_session *session)
1301 {
1302         struct ceph_msg *msg;
1303         int state;
1304
1305         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1306             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1307                 pr_info("mds%d caps stale\n", session->s_mds);
1308         session->s_renew_requested = jiffies;
1309
1310         /* do not try to renew caps until a recovering mds has reconnected
1311          * with its clients. */
1312         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1313         if (state < CEPH_MDS_STATE_RECONNECT) {
1314                 dout("send_renew_caps ignoring mds%d (%s)\n",
1315                      session->s_mds, ceph_mds_state_name(state));
1316                 return 0;
1317         }
1318
1319         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1320                 ceph_mds_state_name(state));
1321         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1322                                  ++session->s_renew_seq);
1323         if (!msg)
1324                 return -ENOMEM;
1325         ceph_con_send(&session->s_con, msg);
1326         return 0;
1327 }
1328
1329 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1330                              struct ceph_mds_session *session, u64 seq)
1331 {
1332         struct ceph_msg *msg;
1333
1334         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1335              session->s_mds, ceph_session_state_name(session->s_state), seq);
1336         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1337         if (!msg)
1338                 return -ENOMEM;
1339         ceph_con_send(&session->s_con, msg);
1340         return 0;
1341 }
1342
1343
1344 /*
1345  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1346  *
1347  * Called under session->s_mutex
1348  */
1349 static void renewed_caps(struct ceph_mds_client *mdsc,
1350                          struct ceph_mds_session *session, int is_renew)
1351 {
1352         int was_stale;
1353         int wake = 0;
1354
1355         spin_lock(&session->s_cap_lock);
1356         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1357
1358         session->s_cap_ttl = session->s_renew_requested +
1359                 mdsc->mdsmap->m_session_timeout*HZ;
1360
1361         if (was_stale) {
1362                 if (time_before(jiffies, session->s_cap_ttl)) {
1363                         pr_info("mds%d caps renewed\n", session->s_mds);
1364                         wake = 1;
1365                 } else {
1366                         pr_info("mds%d caps still stale\n", session->s_mds);
1367                 }
1368         }
1369         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1370              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1371              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1372         spin_unlock(&session->s_cap_lock);
1373
1374         if (wake)
1375                 wake_up_session_caps(session, 0);
1376 }
1377
1378 /*
1379  * send a session close request
1380  */
1381 static int request_close_session(struct ceph_mds_client *mdsc,
1382                                  struct ceph_mds_session *session)
1383 {
1384         struct ceph_msg *msg;
1385
1386         dout("request_close_session mds%d state %s seq %lld\n",
1387              session->s_mds, ceph_session_state_name(session->s_state),
1388              session->s_seq);
1389         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1390         if (!msg)
1391                 return -ENOMEM;
1392         ceph_con_send(&session->s_con, msg);
1393         return 0;
1394 }
1395
1396 /*
1397  * Called with s_mutex held.
1398  */
1399 static int __close_session(struct ceph_mds_client *mdsc,
1400                          struct ceph_mds_session *session)
1401 {
1402         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1403                 return 0;
1404         session->s_state = CEPH_MDS_SESSION_CLOSING;
1405         return request_close_session(mdsc, session);
1406 }
1407
1408 /*
1409  * Trim old(er) caps.
1410  *
1411  * Because we can't cache an inode without one or more caps, we do
1412  * this indirectly: if a cap is unused, we prune its aliases, at which
1413  * point the inode will hopefully get dropped to.
1414  *
1415  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1416  * memory pressure from the MDS, though, so it needn't be perfect.
1417  */
1418 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1419 {
1420         struct ceph_mds_session *session = arg;
1421         struct ceph_inode_info *ci = ceph_inode(inode);
1422         int used, wanted, oissued, mine;
1423
1424         if (session->s_trim_caps <= 0)
1425                 return -1;
1426
1427         spin_lock(&ci->i_ceph_lock);
1428         mine = cap->issued | cap->implemented;
1429         used = __ceph_caps_used(ci);
1430         wanted = __ceph_caps_file_wanted(ci);
1431         oissued = __ceph_caps_issued_other(ci, cap);
1432
1433         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1434              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1435              ceph_cap_string(used), ceph_cap_string(wanted));
1436         if (cap == ci->i_auth_cap) {
1437                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1438                     !list_empty(&ci->i_cap_snaps))
1439                         goto out;
1440                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1441                         goto out;
1442         }
1443         /* The inode has cached pages, but it's no longer used.
1444          * we can safely drop it */
1445         if (wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1446             !(oissued & CEPH_CAP_FILE_CACHE)) {
1447           used = 0;
1448           oissued = 0;
1449         }
1450         if ((used | wanted) & ~oissued & mine)
1451                 goto out;   /* we need these caps */
1452
1453         session->s_trim_caps--;
1454         if (oissued) {
1455                 /* we aren't the only cap.. just remove us */
1456                 __ceph_remove_cap(cap, true);
1457         } else {
1458                 /* try dropping referring dentries */
1459                 spin_unlock(&ci->i_ceph_lock);
1460                 d_prune_aliases(inode);
1461                 dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1462                      inode, cap, atomic_read(&inode->i_count));
1463                 return 0;
1464         }
1465
1466 out:
1467         spin_unlock(&ci->i_ceph_lock);
1468         return 0;
1469 }
1470
1471 /*
1472  * Trim session cap count down to some max number.
1473  */
1474 static int trim_caps(struct ceph_mds_client *mdsc,
1475                      struct ceph_mds_session *session,
1476                      int max_caps)
1477 {
1478         int trim_caps = session->s_nr_caps - max_caps;
1479
1480         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1481              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1482         if (trim_caps > 0) {
1483                 session->s_trim_caps = trim_caps;
1484                 iterate_session_caps(session, trim_caps_cb, session);
1485                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1486                      session->s_mds, session->s_nr_caps, max_caps,
1487                         trim_caps - session->s_trim_caps);
1488                 session->s_trim_caps = 0;
1489         }
1490
1491         ceph_send_cap_releases(mdsc, session);
1492         return 0;
1493 }
1494
1495 static int check_capsnap_flush(struct ceph_inode_info *ci,
1496                                u64 want_snap_seq)
1497 {
1498         int ret = 1;
1499         spin_lock(&ci->i_ceph_lock);
1500         if (want_snap_seq > 0 && !list_empty(&ci->i_cap_snaps)) {
1501                 struct ceph_cap_snap *capsnap =
1502                         list_first_entry(&ci->i_cap_snaps,
1503                                          struct ceph_cap_snap, ci_item);
1504                 ret = capsnap->follows >= want_snap_seq;
1505         }
1506         spin_unlock(&ci->i_ceph_lock);
1507         return ret;
1508 }
1509
1510 static int check_caps_flush(struct ceph_mds_client *mdsc,
1511                             u64 want_flush_tid)
1512 {
1513         struct rb_node *n;
1514         struct ceph_cap_flush *cf;
1515         int ret = 1;
1516
1517         spin_lock(&mdsc->cap_dirty_lock);
1518         n = rb_first(&mdsc->cap_flush_tree);
1519         cf = n ? rb_entry(n, struct ceph_cap_flush, g_node) : NULL;
1520         if (cf && cf->tid <= want_flush_tid) {
1521                 dout("check_caps_flush still flushing tid %llu <= %llu\n",
1522                      cf->tid, want_flush_tid);
1523                 ret = 0;
1524         }
1525         spin_unlock(&mdsc->cap_dirty_lock);
1526         return ret;
1527 }
1528
1529 /*
1530  * flush all dirty inode data to disk.
1531  *
1532  * returns true if we've flushed through want_flush_tid
1533  */
1534 static void wait_caps_flush(struct ceph_mds_client *mdsc,
1535                             u64 want_flush_tid, u64 want_snap_seq)
1536 {
1537         int mds;
1538
1539         dout("check_caps_flush want %llu snap want %llu\n",
1540              want_flush_tid, want_snap_seq);
1541         mutex_lock(&mdsc->mutex);
1542         for (mds = 0; mds < mdsc->max_sessions; ) {
1543                 struct ceph_mds_session *session = mdsc->sessions[mds];
1544                 struct inode *inode = NULL;
1545
1546                 if (!session) {
1547                         mds++;
1548                         continue;
1549                 }
1550                 get_session(session);
1551                 mutex_unlock(&mdsc->mutex);
1552
1553                 mutex_lock(&session->s_mutex);
1554                 if (!list_empty(&session->s_cap_snaps_flushing)) {
1555                         struct ceph_cap_snap *capsnap =
1556                                 list_first_entry(&session->s_cap_snaps_flushing,
1557                                                  struct ceph_cap_snap,
1558                                                  flushing_item);
1559                         struct ceph_inode_info *ci = capsnap->ci;
1560                         if (!check_capsnap_flush(ci, want_snap_seq)) {
1561                                 dout("check_cap_flush still flushing snap %p "
1562                                      "follows %lld <= %lld to mds%d\n",
1563                                      &ci->vfs_inode, capsnap->follows,
1564                                      want_snap_seq, mds);
1565                                 inode = igrab(&ci->vfs_inode);
1566                         }
1567                 }
1568                 mutex_unlock(&session->s_mutex);
1569                 ceph_put_mds_session(session);
1570
1571                 if (inode) {
1572                         wait_event(mdsc->cap_flushing_wq,
1573                                    check_capsnap_flush(ceph_inode(inode),
1574                                                        want_snap_seq));
1575                         iput(inode);
1576                 } else {
1577                         mds++;
1578                 }
1579
1580                 mutex_lock(&mdsc->mutex);
1581         }
1582         mutex_unlock(&mdsc->mutex);
1583
1584         wait_event(mdsc->cap_flushing_wq,
1585                    check_caps_flush(mdsc, want_flush_tid));
1586
1587         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
1588 }
1589
1590 /*
1591  * called under s_mutex
1592  */
1593 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1594                             struct ceph_mds_session *session)
1595 {
1596         struct ceph_msg *msg = NULL;
1597         struct ceph_mds_cap_release *head;
1598         struct ceph_mds_cap_item *item;
1599         struct ceph_cap *cap;
1600         LIST_HEAD(tmp_list);
1601         int num_cap_releases;
1602
1603         spin_lock(&session->s_cap_lock);
1604 again:
1605         list_splice_init(&session->s_cap_releases, &tmp_list);
1606         num_cap_releases = session->s_num_cap_releases;
1607         session->s_num_cap_releases = 0;
1608         spin_unlock(&session->s_cap_lock);
1609
1610         while (!list_empty(&tmp_list)) {
1611                 if (!msg) {
1612                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1613                                         PAGE_SIZE, GFP_NOFS, false);
1614                         if (!msg)
1615                                 goto out_err;
1616                         head = msg->front.iov_base;
1617                         head->num = cpu_to_le32(0);
1618                         msg->front.iov_len = sizeof(*head);
1619                 }
1620                 cap = list_first_entry(&tmp_list, struct ceph_cap,
1621                                         session_caps);
1622                 list_del(&cap->session_caps);
1623                 num_cap_releases--;
1624
1625                 head = msg->front.iov_base;
1626                 le32_add_cpu(&head->num, 1);
1627                 item = msg->front.iov_base + msg->front.iov_len;
1628                 item->ino = cpu_to_le64(cap->cap_ino);
1629                 item->cap_id = cpu_to_le64(cap->cap_id);
1630                 item->migrate_seq = cpu_to_le32(cap->mseq);
1631                 item->seq = cpu_to_le32(cap->issue_seq);
1632                 msg->front.iov_len += sizeof(*item);
1633
1634                 ceph_put_cap(mdsc, cap);
1635
1636                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1637                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1638                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1639                         ceph_con_send(&session->s_con, msg);
1640                         msg = NULL;
1641                 }
1642         }
1643
1644         BUG_ON(num_cap_releases != 0);
1645
1646         spin_lock(&session->s_cap_lock);
1647         if (!list_empty(&session->s_cap_releases))
1648                 goto again;
1649         spin_unlock(&session->s_cap_lock);
1650
1651         if (msg) {
1652                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1653                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1654                 ceph_con_send(&session->s_con, msg);
1655         }
1656         return;
1657 out_err:
1658         pr_err("send_cap_releases mds%d, failed to allocate message\n",
1659                 session->s_mds);
1660         spin_lock(&session->s_cap_lock);
1661         list_splice(&tmp_list, &session->s_cap_releases);
1662         session->s_num_cap_releases += num_cap_releases;
1663         spin_unlock(&session->s_cap_lock);
1664 }
1665
1666 /*
1667  * requests
1668  */
1669
1670 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1671                                     struct inode *dir)
1672 {
1673         struct ceph_inode_info *ci = ceph_inode(dir);
1674         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1675         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1676         size_t size = sizeof(*rinfo->dir_in) + sizeof(*rinfo->dir_dname_len) +
1677                       sizeof(*rinfo->dir_dname) + sizeof(*rinfo->dir_dlease);
1678         int order, num_entries;
1679
1680         spin_lock(&ci->i_ceph_lock);
1681         num_entries = ci->i_files + ci->i_subdirs;
1682         spin_unlock(&ci->i_ceph_lock);
1683         num_entries = max(num_entries, 1);
1684         num_entries = min(num_entries, opt->max_readdir);
1685
1686         order = get_order(size * num_entries);
1687         while (order >= 0) {
1688                 rinfo->dir_in = (void*)__get_free_pages(GFP_KERNEL |
1689                                                         __GFP_NOWARN,
1690                                                         order);
1691                 if (rinfo->dir_in)
1692                         break;
1693                 order--;
1694         }
1695         if (!rinfo->dir_in)
1696                 return -ENOMEM;
1697
1698         num_entries = (PAGE_SIZE << order) / size;
1699         num_entries = min(num_entries, opt->max_readdir);
1700
1701         rinfo->dir_buf_size = PAGE_SIZE << order;
1702         req->r_num_caps = num_entries + 1;
1703         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1704         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1705         return 0;
1706 }
1707
1708 /*
1709  * Create an mds request.
1710  */
1711 struct ceph_mds_request *
1712 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1713 {
1714         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1715
1716         if (!req)
1717                 return ERR_PTR(-ENOMEM);
1718
1719         mutex_init(&req->r_fill_mutex);
1720         req->r_mdsc = mdsc;
1721         req->r_started = jiffies;
1722         req->r_resend_mds = -1;
1723         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1724         INIT_LIST_HEAD(&req->r_unsafe_target_item);
1725         req->r_fmode = -1;
1726         kref_init(&req->r_kref);
1727         INIT_LIST_HEAD(&req->r_wait);
1728         init_completion(&req->r_completion);
1729         init_completion(&req->r_safe_completion);
1730         INIT_LIST_HEAD(&req->r_unsafe_item);
1731
1732         req->r_stamp = current_fs_time(mdsc->fsc->sb);
1733
1734         req->r_op = op;
1735         req->r_direct_mode = mode;
1736         return req;
1737 }
1738
1739 /*
1740  * return oldest (lowest) request, tid in request tree, 0 if none.
1741  *
1742  * called under mdsc->mutex.
1743  */
1744 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1745 {
1746         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1747                 return NULL;
1748         return rb_entry(rb_first(&mdsc->request_tree),
1749                         struct ceph_mds_request, r_node);
1750 }
1751
1752 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1753 {
1754         return mdsc->oldest_tid;
1755 }
1756
1757 /*
1758  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1759  * on build_path_from_dentry in fs/cifs/dir.c.
1760  *
1761  * If @stop_on_nosnap, generate path relative to the first non-snapped
1762  * inode.
1763  *
1764  * Encode hidden .snap dirs as a double /, i.e.
1765  *   foo/.snap/bar -> foo//bar
1766  */
1767 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1768                            int stop_on_nosnap)
1769 {
1770         struct dentry *temp;
1771         char *path;
1772         int len, pos;
1773         unsigned seq;
1774
1775         if (dentry == NULL)
1776                 return ERR_PTR(-EINVAL);
1777
1778 retry:
1779         len = 0;
1780         seq = read_seqbegin(&rename_lock);
1781         rcu_read_lock();
1782         for (temp = dentry; !IS_ROOT(temp);) {
1783                 struct inode *inode = d_inode(temp);
1784                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1785                         len++;  /* slash only */
1786                 else if (stop_on_nosnap && inode &&
1787                          ceph_snap(inode) == CEPH_NOSNAP)
1788                         break;
1789                 else
1790                         len += 1 + temp->d_name.len;
1791                 temp = temp->d_parent;
1792         }
1793         rcu_read_unlock();
1794         if (len)
1795                 len--;  /* no leading '/' */
1796
1797         path = kmalloc(len+1, GFP_NOFS);
1798         if (path == NULL)
1799                 return ERR_PTR(-ENOMEM);
1800         pos = len;
1801         path[pos] = 0;  /* trailing null */
1802         rcu_read_lock();
1803         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1804                 struct inode *inode;
1805
1806                 spin_lock(&temp->d_lock);
1807                 inode = d_inode(temp);
1808                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1809                         dout("build_path path+%d: %p SNAPDIR\n",
1810                              pos, temp);
1811                 } else if (stop_on_nosnap && inode &&
1812                            ceph_snap(inode) == CEPH_NOSNAP) {
1813                         spin_unlock(&temp->d_lock);
1814                         break;
1815                 } else {
1816                         pos -= temp->d_name.len;
1817                         if (pos < 0) {
1818                                 spin_unlock(&temp->d_lock);
1819                                 break;
1820                         }
1821                         strncpy(path + pos, temp->d_name.name,
1822                                 temp->d_name.len);
1823                 }
1824                 spin_unlock(&temp->d_lock);
1825                 if (pos)
1826                         path[--pos] = '/';
1827                 temp = temp->d_parent;
1828         }
1829         rcu_read_unlock();
1830         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1831                 pr_err("build_path did not end path lookup where "
1832                        "expected, namelen is %d, pos is %d\n", len, pos);
1833                 /* presumably this is only possible if racing with a
1834                    rename of one of the parent directories (we can not
1835                    lock the dentries above us to prevent this, but
1836                    retrying should be harmless) */
1837                 kfree(path);
1838                 goto retry;
1839         }
1840
1841         *base = ceph_ino(d_inode(temp));
1842         *plen = len;
1843         dout("build_path on %p %d built %llx '%.*s'\n",
1844              dentry, d_count(dentry), *base, len, path);
1845         return path;
1846 }
1847
1848 static int build_dentry_path(struct dentry *dentry,
1849                              const char **ppath, int *ppathlen, u64 *pino,
1850                              int *pfreepath)
1851 {
1852         char *path;
1853
1854         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP) {
1855                 *pino = ceph_ino(d_inode(dentry->d_parent));
1856                 *ppath = dentry->d_name.name;
1857                 *ppathlen = dentry->d_name.len;
1858                 return 0;
1859         }
1860         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1861         if (IS_ERR(path))
1862                 return PTR_ERR(path);
1863         *ppath = path;
1864         *pfreepath = 1;
1865         return 0;
1866 }
1867
1868 static int build_inode_path(struct inode *inode,
1869                             const char **ppath, int *ppathlen, u64 *pino,
1870                             int *pfreepath)
1871 {
1872         struct dentry *dentry;
1873         char *path;
1874
1875         if (ceph_snap(inode) == CEPH_NOSNAP) {
1876                 *pino = ceph_ino(inode);
1877                 *ppathlen = 0;
1878                 return 0;
1879         }
1880         dentry = d_find_alias(inode);
1881         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1882         dput(dentry);
1883         if (IS_ERR(path))
1884                 return PTR_ERR(path);
1885         *ppath = path;
1886         *pfreepath = 1;
1887         return 0;
1888 }
1889
1890 /*
1891  * request arguments may be specified via an inode *, a dentry *, or
1892  * an explicit ino+path.
1893  */
1894 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1895                                   const char *rpath, u64 rino,
1896                                   const char **ppath, int *pathlen,
1897                                   u64 *ino, int *freepath)
1898 {
1899         int r = 0;
1900
1901         if (rinode) {
1902                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1903                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1904                      ceph_snap(rinode));
1905         } else if (rdentry) {
1906                 r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1907                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1908                      *ppath);
1909         } else if (rpath || rino) {
1910                 *ino = rino;
1911                 *ppath = rpath;
1912                 *pathlen = rpath ? strlen(rpath) : 0;
1913                 dout(" path %.*s\n", *pathlen, rpath);
1914         }
1915
1916         return r;
1917 }
1918
1919 /*
1920  * called under mdsc->mutex
1921  */
1922 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1923                                                struct ceph_mds_request *req,
1924                                                int mds, bool drop_cap_releases)
1925 {
1926         struct ceph_msg *msg;
1927         struct ceph_mds_request_head *head;
1928         const char *path1 = NULL;
1929         const char *path2 = NULL;
1930         u64 ino1 = 0, ino2 = 0;
1931         int pathlen1 = 0, pathlen2 = 0;
1932         int freepath1 = 0, freepath2 = 0;
1933         int len;
1934         u16 releases;
1935         void *p, *end;
1936         int ret;
1937
1938         ret = set_request_path_attr(req->r_inode, req->r_dentry,
1939                               req->r_path1, req->r_ino1.ino,
1940                               &path1, &pathlen1, &ino1, &freepath1);
1941         if (ret < 0) {
1942                 msg = ERR_PTR(ret);
1943                 goto out;
1944         }
1945
1946         ret = set_request_path_attr(NULL, req->r_old_dentry,
1947                               req->r_path2, req->r_ino2.ino,
1948                               &path2, &pathlen2, &ino2, &freepath2);
1949         if (ret < 0) {
1950                 msg = ERR_PTR(ret);
1951                 goto out_free1;
1952         }
1953
1954         len = sizeof(*head) +
1955                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1956                 sizeof(struct ceph_timespec);
1957
1958         /* calculate (max) length for cap releases */
1959         len += sizeof(struct ceph_mds_request_release) *
1960                 (!!req->r_inode_drop + !!req->r_dentry_drop +
1961                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1962         if (req->r_dentry_drop)
1963                 len += req->r_dentry->d_name.len;
1964         if (req->r_old_dentry_drop)
1965                 len += req->r_old_dentry->d_name.len;
1966
1967         msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1968         if (!msg) {
1969                 msg = ERR_PTR(-ENOMEM);
1970                 goto out_free2;
1971         }
1972
1973         msg->hdr.version = cpu_to_le16(2);
1974         msg->hdr.tid = cpu_to_le64(req->r_tid);
1975
1976         head = msg->front.iov_base;
1977         p = msg->front.iov_base + sizeof(*head);
1978         end = msg->front.iov_base + msg->front.iov_len;
1979
1980         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1981         head->op = cpu_to_le32(req->r_op);
1982         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1983         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1984         head->args = req->r_args;
1985
1986         ceph_encode_filepath(&p, end, ino1, path1);
1987         ceph_encode_filepath(&p, end, ino2, path2);
1988
1989         /* make note of release offset, in case we need to replay */
1990         req->r_request_release_offset = p - msg->front.iov_base;
1991
1992         /* cap releases */
1993         releases = 0;
1994         if (req->r_inode_drop)
1995                 releases += ceph_encode_inode_release(&p,
1996                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
1997                       mds, req->r_inode_drop, req->r_inode_unless, 0);
1998         if (req->r_dentry_drop)
1999                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
2000                        mds, req->r_dentry_drop, req->r_dentry_unless);
2001         if (req->r_old_dentry_drop)
2002                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2003                        mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
2004         if (req->r_old_inode_drop)
2005                 releases += ceph_encode_inode_release(&p,
2006                       d_inode(req->r_old_dentry),
2007                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2008
2009         if (drop_cap_releases) {
2010                 releases = 0;
2011                 p = msg->front.iov_base + req->r_request_release_offset;
2012         }
2013
2014         head->num_releases = cpu_to_le16(releases);
2015
2016         /* time stamp */
2017         {
2018                 struct ceph_timespec ts;
2019                 ceph_encode_timespec(&ts, &req->r_stamp);
2020                 ceph_encode_copy(&p, &ts, sizeof(ts));
2021         }
2022
2023         BUG_ON(p > end);
2024         msg->front.iov_len = p - msg->front.iov_base;
2025         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2026
2027         if (req->r_pagelist) {
2028                 struct ceph_pagelist *pagelist = req->r_pagelist;
2029                 atomic_inc(&pagelist->refcnt);
2030                 ceph_msg_data_add_pagelist(msg, pagelist);
2031                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2032         } else {
2033                 msg->hdr.data_len = 0;
2034         }
2035
2036         msg->hdr.data_off = cpu_to_le16(0);
2037
2038 out_free2:
2039         if (freepath2)
2040                 kfree((char *)path2);
2041 out_free1:
2042         if (freepath1)
2043                 kfree((char *)path1);
2044 out:
2045         return msg;
2046 }
2047
2048 /*
2049  * called under mdsc->mutex if error, under no mutex if
2050  * success.
2051  */
2052 static void complete_request(struct ceph_mds_client *mdsc,
2053                              struct ceph_mds_request *req)
2054 {
2055         if (req->r_callback)
2056                 req->r_callback(mdsc, req);
2057         else
2058                 complete_all(&req->r_completion);
2059 }
2060
2061 /*
2062  * called under mdsc->mutex
2063  */
2064 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2065                                   struct ceph_mds_request *req,
2066                                   int mds, bool drop_cap_releases)
2067 {
2068         struct ceph_mds_request_head *rhead;
2069         struct ceph_msg *msg;
2070         int flags = 0;
2071
2072         req->r_attempts++;
2073         if (req->r_inode) {
2074                 struct ceph_cap *cap =
2075                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2076
2077                 if (cap)
2078                         req->r_sent_on_mseq = cap->mseq;
2079                 else
2080                         req->r_sent_on_mseq = -1;
2081         }
2082         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2083              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2084
2085         if (req->r_got_unsafe) {
2086                 void *p;
2087                 /*
2088                  * Replay.  Do not regenerate message (and rebuild
2089                  * paths, etc.); just use the original message.
2090                  * Rebuilding paths will break for renames because
2091                  * d_move mangles the src name.
2092                  */
2093                 msg = req->r_request;
2094                 rhead = msg->front.iov_base;
2095
2096                 flags = le32_to_cpu(rhead->flags);
2097                 flags |= CEPH_MDS_FLAG_REPLAY;
2098                 rhead->flags = cpu_to_le32(flags);
2099
2100                 if (req->r_target_inode)
2101                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2102
2103                 rhead->num_retry = req->r_attempts - 1;
2104
2105                 /* remove cap/dentry releases from message */
2106                 rhead->num_releases = 0;
2107
2108                 /* time stamp */
2109                 p = msg->front.iov_base + req->r_request_release_offset;
2110                 {
2111                         struct ceph_timespec ts;
2112                         ceph_encode_timespec(&ts, &req->r_stamp);
2113                         ceph_encode_copy(&p, &ts, sizeof(ts));
2114                 }
2115
2116                 msg->front.iov_len = p - msg->front.iov_base;
2117                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2118                 return 0;
2119         }
2120
2121         if (req->r_request) {
2122                 ceph_msg_put(req->r_request);
2123                 req->r_request = NULL;
2124         }
2125         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2126         if (IS_ERR(msg)) {
2127                 req->r_err = PTR_ERR(msg);
2128                 return PTR_ERR(msg);
2129         }
2130         req->r_request = msg;
2131
2132         rhead = msg->front.iov_base;
2133         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2134         if (req->r_got_unsafe)
2135                 flags |= CEPH_MDS_FLAG_REPLAY;
2136         if (req->r_locked_dir)
2137                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2138         rhead->flags = cpu_to_le32(flags);
2139         rhead->num_fwd = req->r_num_fwd;
2140         rhead->num_retry = req->r_attempts - 1;
2141         rhead->ino = 0;
2142
2143         dout(" r_locked_dir = %p\n", req->r_locked_dir);
2144         return 0;
2145 }
2146
2147 /*
2148  * send request, or put it on the appropriate wait list.
2149  */
2150 static int __do_request(struct ceph_mds_client *mdsc,
2151                         struct ceph_mds_request *req)
2152 {
2153         struct ceph_mds_session *session = NULL;
2154         int mds = -1;
2155         int err = 0;
2156
2157         if (req->r_err || req->r_got_result) {
2158                 if (req->r_aborted)
2159                         __unregister_request(mdsc, req);
2160                 goto out;
2161         }
2162
2163         if (req->r_timeout &&
2164             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2165                 dout("do_request timed out\n");
2166                 err = -EIO;
2167                 goto finish;
2168         }
2169         if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2170                 dout("do_request forced umount\n");
2171                 err = -EIO;
2172                 goto finish;
2173         }
2174
2175         put_request_session(req);
2176
2177         mds = __choose_mds(mdsc, req);
2178         if (mds < 0 ||
2179             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2180                 dout("do_request no mds or not active, waiting for map\n");
2181                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2182                 goto out;
2183         }
2184
2185         /* get, open session */
2186         session = __ceph_lookup_mds_session(mdsc, mds);
2187         if (!session) {
2188                 session = register_session(mdsc, mds);
2189                 if (IS_ERR(session)) {
2190                         err = PTR_ERR(session);
2191                         goto finish;
2192                 }
2193         }
2194         req->r_session = get_session(session);
2195
2196         dout("do_request mds%d session %p state %s\n", mds, session,
2197              ceph_session_state_name(session->s_state));
2198         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2199             session->s_state != CEPH_MDS_SESSION_HUNG) {
2200                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2201                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2202                         __open_session(mdsc, session);
2203                 list_add(&req->r_wait, &session->s_waiting);
2204                 goto out_session;
2205         }
2206
2207         /* send request */
2208         req->r_resend_mds = -1;   /* forget any previous mds hint */
2209
2210         if (req->r_request_started == 0)   /* note request start time */
2211                 req->r_request_started = jiffies;
2212
2213         err = __prepare_send_request(mdsc, req, mds, false);
2214         if (!err) {
2215                 ceph_msg_get(req->r_request);
2216                 ceph_con_send(&session->s_con, req->r_request);
2217         }
2218
2219 out_session:
2220         ceph_put_mds_session(session);
2221 finish:
2222         if (err) {
2223                 dout("__do_request early error %d\n", err);
2224                 req->r_err = err;
2225                 complete_request(mdsc, req);
2226                 __unregister_request(mdsc, req);
2227         }
2228 out:
2229         return err;
2230 }
2231
2232 /*
2233  * called under mdsc->mutex
2234  */
2235 static void __wake_requests(struct ceph_mds_client *mdsc,
2236                             struct list_head *head)
2237 {
2238         struct ceph_mds_request *req;
2239         LIST_HEAD(tmp_list);
2240
2241         list_splice_init(head, &tmp_list);
2242
2243         while (!list_empty(&tmp_list)) {
2244                 req = list_entry(tmp_list.next,
2245                                  struct ceph_mds_request, r_wait);
2246                 list_del_init(&req->r_wait);
2247                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2248                 __do_request(mdsc, req);
2249         }
2250 }
2251
2252 /*
2253  * Wake up threads with requests pending for @mds, so that they can
2254  * resubmit their requests to a possibly different mds.
2255  */
2256 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2257 {
2258         struct ceph_mds_request *req;
2259         struct rb_node *p = rb_first(&mdsc->request_tree);
2260
2261         dout("kick_requests mds%d\n", mds);
2262         while (p) {
2263                 req = rb_entry(p, struct ceph_mds_request, r_node);
2264                 p = rb_next(p);
2265                 if (req->r_got_unsafe)
2266                         continue;
2267                 if (req->r_attempts > 0)
2268                         continue; /* only new requests */
2269                 if (req->r_session &&
2270                     req->r_session->s_mds == mds) {
2271                         dout(" kicking tid %llu\n", req->r_tid);
2272                         list_del_init(&req->r_wait);
2273                         __do_request(mdsc, req);
2274                 }
2275         }
2276 }
2277
2278 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2279                               struct ceph_mds_request *req)
2280 {
2281         dout("submit_request on %p\n", req);
2282         mutex_lock(&mdsc->mutex);
2283         __register_request(mdsc, req, NULL);
2284         __do_request(mdsc, req);
2285         mutex_unlock(&mdsc->mutex);
2286 }
2287
2288 /*
2289  * Synchrously perform an mds request.  Take care of all of the
2290  * session setup, forwarding, retry details.
2291  */
2292 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2293                          struct inode *dir,
2294                          struct ceph_mds_request *req)
2295 {
2296         int err;
2297
2298         dout("do_request on %p\n", req);
2299
2300         /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2301         if (req->r_inode)
2302                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2303         if (req->r_locked_dir)
2304                 ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2305         if (req->r_old_dentry_dir)
2306                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2307                                   CEPH_CAP_PIN);
2308
2309         /* deny access to directories with pool_ns layouts */
2310         if (req->r_inode && S_ISDIR(req->r_inode->i_mode) &&
2311             ceph_inode(req->r_inode)->i_pool_ns_len)
2312                 return -EIO;
2313         if (req->r_locked_dir &&
2314             ceph_inode(req->r_locked_dir)->i_pool_ns_len)
2315                 return -EIO;
2316
2317         /* issue */
2318         mutex_lock(&mdsc->mutex);
2319         __register_request(mdsc, req, dir);
2320         __do_request(mdsc, req);
2321
2322         if (req->r_err) {
2323                 err = req->r_err;
2324                 goto out;
2325         }
2326
2327         /* wait */
2328         mutex_unlock(&mdsc->mutex);
2329         dout("do_request waiting\n");
2330         if (!req->r_timeout && req->r_wait_for_completion) {
2331                 err = req->r_wait_for_completion(mdsc, req);
2332         } else {
2333                 long timeleft = wait_for_completion_killable_timeout(
2334                                         &req->r_completion,
2335                                         ceph_timeout_jiffies(req->r_timeout));
2336                 if (timeleft > 0)
2337                         err = 0;
2338                 else if (!timeleft)
2339                         err = -EIO;  /* timed out */
2340                 else
2341                         err = timeleft;  /* killed */
2342         }
2343         dout("do_request waited, got %d\n", err);
2344         mutex_lock(&mdsc->mutex);
2345
2346         /* only abort if we didn't race with a real reply */
2347         if (req->r_got_result) {
2348                 err = le32_to_cpu(req->r_reply_info.head->result);
2349         } else if (err < 0) {
2350                 dout("aborted request %lld with %d\n", req->r_tid, err);
2351
2352                 /*
2353                  * ensure we aren't running concurrently with
2354                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2355                  * rely on locks (dir mutex) held by our caller.
2356                  */
2357                 mutex_lock(&req->r_fill_mutex);
2358                 req->r_err = err;
2359                 req->r_aborted = true;
2360                 mutex_unlock(&req->r_fill_mutex);
2361
2362                 if (req->r_locked_dir &&
2363                     (req->r_op & CEPH_MDS_OP_WRITE))
2364                         ceph_invalidate_dir_request(req);
2365         } else {
2366                 err = req->r_err;
2367         }
2368
2369 out:
2370         mutex_unlock(&mdsc->mutex);
2371         dout("do_request %p done, result %d\n", req, err);
2372         return err;
2373 }
2374
2375 /*
2376  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2377  * namespace request.
2378  */
2379 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2380 {
2381         struct inode *inode = req->r_locked_dir;
2382
2383         dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2384
2385         ceph_dir_clear_complete(inode);
2386         if (req->r_dentry)
2387                 ceph_invalidate_dentry_lease(req->r_dentry);
2388         if (req->r_old_dentry)
2389                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2390 }
2391
2392 /*
2393  * Handle mds reply.
2394  *
2395  * We take the session mutex and parse and process the reply immediately.
2396  * This preserves the logical ordering of replies, capabilities, etc., sent
2397  * by the MDS as they are applied to our local cache.
2398  */
2399 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2400 {
2401         struct ceph_mds_client *mdsc = session->s_mdsc;
2402         struct ceph_mds_request *req;
2403         struct ceph_mds_reply_head *head = msg->front.iov_base;
2404         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2405         struct ceph_snap_realm *realm;
2406         u64 tid;
2407         int err, result;
2408         int mds = session->s_mds;
2409
2410         if (msg->front.iov_len < sizeof(*head)) {
2411                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2412                 ceph_msg_dump(msg);
2413                 return;
2414         }
2415
2416         /* get request, session */
2417         tid = le64_to_cpu(msg->hdr.tid);
2418         mutex_lock(&mdsc->mutex);
2419         req = __lookup_request(mdsc, tid);
2420         if (!req) {
2421                 dout("handle_reply on unknown tid %llu\n", tid);
2422                 mutex_unlock(&mdsc->mutex);
2423                 return;
2424         }
2425         dout("handle_reply %p\n", req);
2426
2427         /* correct session? */
2428         if (req->r_session != session) {
2429                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2430                        " not mds%d\n", tid, session->s_mds,
2431                        req->r_session ? req->r_session->s_mds : -1);
2432                 mutex_unlock(&mdsc->mutex);
2433                 goto out;
2434         }
2435
2436         /* dup? */
2437         if ((req->r_got_unsafe && !head->safe) ||
2438             (req->r_got_safe && head->safe)) {
2439                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2440                            head->safe ? "safe" : "unsafe", tid, mds);
2441                 mutex_unlock(&mdsc->mutex);
2442                 goto out;
2443         }
2444         if (req->r_got_safe) {
2445                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2446                            tid, mds);
2447                 mutex_unlock(&mdsc->mutex);
2448                 goto out;
2449         }
2450
2451         result = le32_to_cpu(head->result);
2452
2453         /*
2454          * Handle an ESTALE
2455          * if we're not talking to the authority, send to them
2456          * if the authority has changed while we weren't looking,
2457          * send to new authority
2458          * Otherwise we just have to return an ESTALE
2459          */
2460         if (result == -ESTALE) {
2461                 dout("got ESTALE on request %llu", req->r_tid);
2462                 req->r_resend_mds = -1;
2463                 if (req->r_direct_mode != USE_AUTH_MDS) {
2464                         dout("not using auth, setting for that now");
2465                         req->r_direct_mode = USE_AUTH_MDS;
2466                         __do_request(mdsc, req);
2467                         mutex_unlock(&mdsc->mutex);
2468                         goto out;
2469                 } else  {
2470                         int mds = __choose_mds(mdsc, req);
2471                         if (mds >= 0 && mds != req->r_session->s_mds) {
2472                                 dout("but auth changed, so resending");
2473                                 __do_request(mdsc, req);
2474                                 mutex_unlock(&mdsc->mutex);
2475                                 goto out;
2476                         }
2477                 }
2478                 dout("have to return ESTALE on request %llu", req->r_tid);
2479         }
2480
2481
2482         if (head->safe) {
2483                 req->r_got_safe = true;
2484                 __unregister_request(mdsc, req);
2485
2486                 if (req->r_got_unsafe) {
2487                         /*
2488                          * We already handled the unsafe response, now do the
2489                          * cleanup.  No need to examine the response; the MDS
2490                          * doesn't include any result info in the safe
2491                          * response.  And even if it did, there is nothing
2492                          * useful we could do with a revised return value.
2493                          */
2494                         dout("got safe reply %llu, mds%d\n", tid, mds);
2495                         list_del_init(&req->r_unsafe_item);
2496
2497                         /* last unsafe request during umount? */
2498                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2499                                 complete_all(&mdsc->safe_umount_waiters);
2500                         mutex_unlock(&mdsc->mutex);
2501                         goto out;
2502                 }
2503         } else {
2504                 req->r_got_unsafe = true;
2505                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2506                 if (req->r_unsafe_dir) {
2507                         struct ceph_inode_info *ci =
2508                                         ceph_inode(req->r_unsafe_dir);
2509                         spin_lock(&ci->i_unsafe_lock);
2510                         list_add_tail(&req->r_unsafe_dir_item,
2511                                       &ci->i_unsafe_dirops);
2512                         spin_unlock(&ci->i_unsafe_lock);
2513                 }
2514         }
2515
2516         dout("handle_reply tid %lld result %d\n", tid, result);
2517         rinfo = &req->r_reply_info;
2518         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2519         mutex_unlock(&mdsc->mutex);
2520
2521         mutex_lock(&session->s_mutex);
2522         if (err < 0) {
2523                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2524                 ceph_msg_dump(msg);
2525                 goto out_err;
2526         }
2527
2528         /* snap trace */
2529         realm = NULL;
2530         if (rinfo->snapblob_len) {
2531                 down_write(&mdsc->snap_rwsem);
2532                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2533                                 rinfo->snapblob + rinfo->snapblob_len,
2534                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2535                                 &realm);
2536                 downgrade_write(&mdsc->snap_rwsem);
2537         } else {
2538                 down_read(&mdsc->snap_rwsem);
2539         }
2540
2541         /* insert trace into our cache */
2542         mutex_lock(&req->r_fill_mutex);
2543         current->journal_info = req;
2544         err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2545         if (err == 0) {
2546                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2547                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2548                         ceph_readdir_prepopulate(req, req->r_session);
2549                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2550         }
2551         current->journal_info = NULL;
2552         mutex_unlock(&req->r_fill_mutex);
2553
2554         up_read(&mdsc->snap_rwsem);
2555         if (realm)
2556                 ceph_put_snap_realm(mdsc, realm);
2557
2558         if (err == 0 && req->r_got_unsafe && req->r_target_inode) {
2559                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
2560                 spin_lock(&ci->i_unsafe_lock);
2561                 list_add_tail(&req->r_unsafe_target_item, &ci->i_unsafe_iops);
2562                 spin_unlock(&ci->i_unsafe_lock);
2563         }
2564 out_err:
2565         mutex_lock(&mdsc->mutex);
2566         if (!req->r_aborted) {
2567                 if (err) {
2568                         req->r_err = err;
2569                 } else {
2570                         req->r_reply =  ceph_msg_get(msg);
2571                         req->r_got_result = true;
2572                 }
2573         } else {
2574                 dout("reply arrived after request %lld was aborted\n", tid);
2575         }
2576         mutex_unlock(&mdsc->mutex);
2577
2578         mutex_unlock(&session->s_mutex);
2579
2580         /* kick calling process */
2581         complete_request(mdsc, req);
2582 out:
2583         ceph_mdsc_put_request(req);
2584         return;
2585 }
2586
2587
2588
2589 /*
2590  * handle mds notification that our request has been forwarded.
2591  */
2592 static void handle_forward(struct ceph_mds_client *mdsc,
2593                            struct ceph_mds_session *session,
2594                            struct ceph_msg *msg)
2595 {
2596         struct ceph_mds_request *req;
2597         u64 tid = le64_to_cpu(msg->hdr.tid);
2598         u32 next_mds;
2599         u32 fwd_seq;
2600         int err = -EINVAL;
2601         void *p = msg->front.iov_base;
2602         void *end = p + msg->front.iov_len;
2603
2604         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2605         next_mds = ceph_decode_32(&p);
2606         fwd_seq = ceph_decode_32(&p);
2607
2608         mutex_lock(&mdsc->mutex);
2609         req = __lookup_request(mdsc, tid);
2610         if (!req) {
2611                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2612                 goto out;  /* dup reply? */
2613         }
2614
2615         if (req->r_aborted) {
2616                 dout("forward tid %llu aborted, unregistering\n", tid);
2617                 __unregister_request(mdsc, req);
2618         } else if (fwd_seq <= req->r_num_fwd) {
2619                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2620                      tid, next_mds, req->r_num_fwd, fwd_seq);
2621         } else {
2622                 /* resend. forward race not possible; mds would drop */
2623                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2624                 BUG_ON(req->r_err);
2625                 BUG_ON(req->r_got_result);
2626                 req->r_attempts = 0;
2627                 req->r_num_fwd = fwd_seq;
2628                 req->r_resend_mds = next_mds;
2629                 put_request_session(req);
2630                 __do_request(mdsc, req);
2631         }
2632         ceph_mdsc_put_request(req);
2633 out:
2634         mutex_unlock(&mdsc->mutex);
2635         return;
2636
2637 bad:
2638         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2639 }
2640
2641 /*
2642  * handle a mds session control message
2643  */
2644 static void handle_session(struct ceph_mds_session *session,
2645                            struct ceph_msg *msg)
2646 {
2647         struct ceph_mds_client *mdsc = session->s_mdsc;
2648         u32 op;
2649         u64 seq;
2650         int mds = session->s_mds;
2651         struct ceph_mds_session_head *h = msg->front.iov_base;
2652         int wake = 0;
2653
2654         /* decode */
2655         if (msg->front.iov_len != sizeof(*h))
2656                 goto bad;
2657         op = le32_to_cpu(h->op);
2658         seq = le64_to_cpu(h->seq);
2659
2660         mutex_lock(&mdsc->mutex);
2661         if (op == CEPH_SESSION_CLOSE)
2662                 __unregister_session(mdsc, session);
2663         /* FIXME: this ttl calculation is generous */
2664         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2665         mutex_unlock(&mdsc->mutex);
2666
2667         mutex_lock(&session->s_mutex);
2668
2669         dout("handle_session mds%d %s %p state %s seq %llu\n",
2670              mds, ceph_session_op_name(op), session,
2671              ceph_session_state_name(session->s_state), seq);
2672
2673         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2674                 session->s_state = CEPH_MDS_SESSION_OPEN;
2675                 pr_info("mds%d came back\n", session->s_mds);
2676         }
2677
2678         switch (op) {
2679         case CEPH_SESSION_OPEN:
2680                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2681                         pr_info("mds%d reconnect success\n", session->s_mds);
2682                 session->s_state = CEPH_MDS_SESSION_OPEN;
2683                 renewed_caps(mdsc, session, 0);
2684                 wake = 1;
2685                 if (mdsc->stopping)
2686                         __close_session(mdsc, session);
2687                 break;
2688
2689         case CEPH_SESSION_RENEWCAPS:
2690                 if (session->s_renew_seq == seq)
2691                         renewed_caps(mdsc, session, 1);
2692                 break;
2693
2694         case CEPH_SESSION_CLOSE:
2695                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2696                         pr_info("mds%d reconnect denied\n", session->s_mds);
2697                 cleanup_session_requests(mdsc, session);
2698                 remove_session_caps(session);
2699                 wake = 2; /* for good measure */
2700                 wake_up_all(&mdsc->session_close_wq);
2701                 break;
2702
2703         case CEPH_SESSION_STALE:
2704                 pr_info("mds%d caps went stale, renewing\n",
2705                         session->s_mds);
2706                 spin_lock(&session->s_gen_ttl_lock);
2707                 session->s_cap_gen++;
2708                 session->s_cap_ttl = jiffies - 1;
2709                 spin_unlock(&session->s_gen_ttl_lock);
2710                 send_renew_caps(mdsc, session);
2711                 break;
2712
2713         case CEPH_SESSION_RECALL_STATE:
2714                 trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2715                 break;
2716
2717         case CEPH_SESSION_FLUSHMSG:
2718                 send_flushmsg_ack(mdsc, session, seq);
2719                 break;
2720
2721         case CEPH_SESSION_FORCE_RO:
2722                 dout("force_session_readonly %p\n", session);
2723                 spin_lock(&session->s_cap_lock);
2724                 session->s_readonly = true;
2725                 spin_unlock(&session->s_cap_lock);
2726                 wake_up_session_caps(session, 0);
2727                 break;
2728
2729         default:
2730                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2731                 WARN_ON(1);
2732         }
2733
2734         mutex_unlock(&session->s_mutex);
2735         if (wake) {
2736                 mutex_lock(&mdsc->mutex);
2737                 __wake_requests(mdsc, &session->s_waiting);
2738                 if (wake == 2)
2739                         kick_requests(mdsc, mds);
2740                 mutex_unlock(&mdsc->mutex);
2741         }
2742         return;
2743
2744 bad:
2745         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2746                (int)msg->front.iov_len);
2747         ceph_msg_dump(msg);
2748         return;
2749 }
2750
2751
2752 /*
2753  * called under session->mutex.
2754  */
2755 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2756                                    struct ceph_mds_session *session)
2757 {
2758         struct ceph_mds_request *req, *nreq;
2759         struct rb_node *p;
2760         int err;
2761
2762         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2763
2764         mutex_lock(&mdsc->mutex);
2765         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2766                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
2767                 if (!err) {
2768                         ceph_msg_get(req->r_request);
2769                         ceph_con_send(&session->s_con, req->r_request);
2770                 }
2771         }
2772
2773         /*
2774          * also re-send old requests when MDS enters reconnect stage. So that MDS
2775          * can process completed request in clientreplay stage.
2776          */
2777         p = rb_first(&mdsc->request_tree);
2778         while (p) {
2779                 req = rb_entry(p, struct ceph_mds_request, r_node);
2780                 p = rb_next(p);
2781                 if (req->r_got_unsafe)
2782                         continue;
2783                 if (req->r_attempts == 0)
2784                         continue; /* only old requests */
2785                 if (req->r_session &&
2786                     req->r_session->s_mds == session->s_mds) {
2787                         err = __prepare_send_request(mdsc, req,
2788                                                      session->s_mds, true);
2789                         if (!err) {
2790                                 ceph_msg_get(req->r_request);
2791                                 ceph_con_send(&session->s_con, req->r_request);
2792                         }
2793                 }
2794         }
2795         mutex_unlock(&mdsc->mutex);
2796 }
2797
2798 /*
2799  * Encode information about a cap for a reconnect with the MDS.
2800  */
2801 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2802                           void *arg)
2803 {
2804         union {
2805                 struct ceph_mds_cap_reconnect v2;
2806                 struct ceph_mds_cap_reconnect_v1 v1;
2807         } rec;
2808         size_t reclen;
2809         struct ceph_inode_info *ci;
2810         struct ceph_reconnect_state *recon_state = arg;
2811         struct ceph_pagelist *pagelist = recon_state->pagelist;
2812         char *path;
2813         int pathlen, err;
2814         u64 pathbase;
2815         struct dentry *dentry;
2816
2817         ci = cap->ci;
2818
2819         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2820              inode, ceph_vinop(inode), cap, cap->cap_id,
2821              ceph_cap_string(cap->issued));
2822         err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2823         if (err)
2824                 return err;
2825
2826         dentry = d_find_alias(inode);
2827         if (dentry) {
2828                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2829                 if (IS_ERR(path)) {
2830                         err = PTR_ERR(path);
2831                         goto out_dput;
2832                 }
2833         } else {
2834                 path = NULL;
2835                 pathlen = 0;
2836         }
2837         err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2838         if (err)
2839                 goto out_free;
2840
2841         spin_lock(&ci->i_ceph_lock);
2842         cap->seq = 0;        /* reset cap seq */
2843         cap->issue_seq = 0;  /* and issue_seq */
2844         cap->mseq = 0;       /* and migrate_seq */
2845         cap->cap_gen = cap->session->s_cap_gen;
2846
2847         if (recon_state->flock) {
2848                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2849                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2850                 rec.v2.issued = cpu_to_le32(cap->issued);
2851                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2852                 rec.v2.pathbase = cpu_to_le64(pathbase);
2853                 rec.v2.flock_len = 0;
2854                 reclen = sizeof(rec.v2);
2855         } else {
2856                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2857                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2858                 rec.v1.issued = cpu_to_le32(cap->issued);
2859                 rec.v1.size = cpu_to_le64(inode->i_size);
2860                 ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2861                 ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2862                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2863                 rec.v1.pathbase = cpu_to_le64(pathbase);
2864                 reclen = sizeof(rec.v1);
2865         }
2866         spin_unlock(&ci->i_ceph_lock);
2867
2868         if (recon_state->flock) {
2869                 int num_fcntl_locks, num_flock_locks;
2870                 struct ceph_filelock *flocks;
2871
2872 encode_again:
2873                 ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2874                 flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2875                                  sizeof(struct ceph_filelock), GFP_NOFS);
2876                 if (!flocks) {
2877                         err = -ENOMEM;
2878                         goto out_free;
2879                 }
2880                 err = ceph_encode_locks_to_buffer(inode, flocks,
2881                                                   num_fcntl_locks,
2882                                                   num_flock_locks);
2883                 if (err) {
2884                         kfree(flocks);
2885                         if (err == -ENOSPC)
2886                                 goto encode_again;
2887                         goto out_free;
2888                 }
2889                 /*
2890                  * number of encoded locks is stable, so copy to pagelist
2891                  */
2892                 rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2893                                     (num_fcntl_locks+num_flock_locks) *
2894                                     sizeof(struct ceph_filelock));
2895                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2896                 if (!err)
2897                         err = ceph_locks_to_pagelist(flocks, pagelist,
2898                                                      num_fcntl_locks,
2899                                                      num_flock_locks);
2900                 kfree(flocks);
2901         } else {
2902                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2903         }
2904
2905         recon_state->nr_caps++;
2906 out_free:
2907         kfree(path);
2908 out_dput:
2909         dput(dentry);
2910         return err;
2911 }
2912
2913
2914 /*
2915  * If an MDS fails and recovers, clients need to reconnect in order to
2916  * reestablish shared state.  This includes all caps issued through
2917  * this session _and_ the snap_realm hierarchy.  Because it's not
2918  * clear which snap realms the mds cares about, we send everything we
2919  * know about.. that ensures we'll then get any new info the
2920  * recovering MDS might have.
2921  *
2922  * This is a relatively heavyweight operation, but it's rare.
2923  *
2924  * called with mdsc->mutex held.
2925  */
2926 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2927                                struct ceph_mds_session *session)
2928 {
2929         struct ceph_msg *reply;
2930         struct rb_node *p;
2931         int mds = session->s_mds;
2932         int err = -ENOMEM;
2933         int s_nr_caps;
2934         struct ceph_pagelist *pagelist;
2935         struct ceph_reconnect_state recon_state;
2936
2937         pr_info("mds%d reconnect start\n", mds);
2938
2939         pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2940         if (!pagelist)
2941                 goto fail_nopagelist;
2942         ceph_pagelist_init(pagelist);
2943
2944         reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2945         if (!reply)
2946                 goto fail_nomsg;
2947
2948         mutex_lock(&session->s_mutex);
2949         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2950         session->s_seq = 0;
2951
2952         dout("session %p state %s\n", session,
2953              ceph_session_state_name(session->s_state));
2954
2955         spin_lock(&session->s_gen_ttl_lock);
2956         session->s_cap_gen++;
2957         spin_unlock(&session->s_gen_ttl_lock);
2958
2959         spin_lock(&session->s_cap_lock);
2960         /* don't know if session is readonly */
2961         session->s_readonly = 0;
2962         /*
2963          * notify __ceph_remove_cap() that we are composing cap reconnect.
2964          * If a cap get released before being added to the cap reconnect,
2965          * __ceph_remove_cap() should skip queuing cap release.
2966          */
2967         session->s_cap_reconnect = 1;
2968         /* drop old cap expires; we're about to reestablish that state */
2969         cleanup_cap_releases(mdsc, session);
2970
2971         /* trim unused caps to reduce MDS's cache rejoin time */
2972         if (mdsc->fsc->sb->s_root)
2973                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
2974
2975         ceph_con_close(&session->s_con);
2976         ceph_con_open(&session->s_con,
2977                       CEPH_ENTITY_TYPE_MDS, mds,
2978                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2979
2980         /* replay unsafe requests */
2981         replay_unsafe_requests(mdsc, session);
2982
2983         down_read(&mdsc->snap_rwsem);
2984
2985         /* traverse this session's caps */
2986         s_nr_caps = session->s_nr_caps;
2987         err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2988         if (err)
2989                 goto fail;
2990
2991         recon_state.nr_caps = 0;
2992         recon_state.pagelist = pagelist;
2993         recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2994         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2995         if (err < 0)
2996                 goto fail;
2997
2998         spin_lock(&session->s_cap_lock);
2999         session->s_cap_reconnect = 0;
3000         spin_unlock(&session->s_cap_lock);
3001
3002         /*
3003          * snaprealms.  we provide mds with the ino, seq (version), and
3004          * parent for all of our realms.  If the mds has any newer info,
3005          * it will tell us.
3006          */
3007         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3008                 struct ceph_snap_realm *realm =
3009                         rb_entry(p, struct ceph_snap_realm, node);
3010                 struct ceph_mds_snaprealm_reconnect sr_rec;
3011
3012                 dout(" adding snap realm %llx seq %lld parent %llx\n",
3013                      realm->ino, realm->seq, realm->parent_ino);
3014                 sr_rec.ino = cpu_to_le64(realm->ino);
3015                 sr_rec.seq = cpu_to_le64(realm->seq);
3016                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
3017                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3018                 if (err)
3019                         goto fail;
3020         }
3021
3022         if (recon_state.flock)
3023                 reply->hdr.version = cpu_to_le16(2);
3024
3025         /* raced with cap release? */
3026         if (s_nr_caps != recon_state.nr_caps) {
3027                 struct page *page = list_first_entry(&pagelist->head,
3028                                                      struct page, lru);
3029                 __le32 *addr = kmap_atomic(page);
3030                 *addr = cpu_to_le32(recon_state.nr_caps);
3031                 kunmap_atomic(addr);
3032         }
3033
3034         reply->hdr.data_len = cpu_to_le32(pagelist->length);
3035         ceph_msg_data_add_pagelist(reply, pagelist);
3036
3037         ceph_early_kick_flushing_caps(mdsc, session);
3038
3039         ceph_con_send(&session->s_con, reply);
3040
3041         mutex_unlock(&session->s_mutex);
3042
3043         mutex_lock(&mdsc->mutex);
3044         __wake_requests(mdsc, &session->s_waiting);
3045         mutex_unlock(&mdsc->mutex);
3046
3047         up_read(&mdsc->snap_rwsem);
3048         return;
3049
3050 fail:
3051         ceph_msg_put(reply);
3052         up_read(&mdsc->snap_rwsem);
3053         mutex_unlock(&session->s_mutex);
3054 fail_nomsg:
3055         ceph_pagelist_release(pagelist);
3056 fail_nopagelist:
3057         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3058         return;
3059 }
3060
3061
3062 /*
3063  * compare old and new mdsmaps, kicking requests
3064  * and closing out old connections as necessary
3065  *
3066  * called under mdsc->mutex.
3067  */
3068 static void check_new_map(struct ceph_mds_client *mdsc,
3069                           struct ceph_mdsmap *newmap,
3070                           struct ceph_mdsmap *oldmap)
3071 {
3072         int i;
3073         int oldstate, newstate;
3074         struct ceph_mds_session *s;
3075
3076         dout("check_new_map new %u old %u\n",
3077              newmap->m_epoch, oldmap->m_epoch);
3078
3079         for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
3080                 if (mdsc->sessions[i] == NULL)
3081                         continue;
3082                 s = mdsc->sessions[i];
3083                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3084                 newstate = ceph_mdsmap_get_state(newmap, i);
3085
3086                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3087                      i, ceph_mds_state_name(oldstate),
3088                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3089                      ceph_mds_state_name(newstate),
3090                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3091                      ceph_session_state_name(s->s_state));
3092
3093                 if (i >= newmap->m_max_mds ||
3094                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
3095                            ceph_mdsmap_get_addr(newmap, i),
3096                            sizeof(struct ceph_entity_addr))) {
3097                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
3098                                 /* the session never opened, just close it
3099                                  * out now */
3100                                 __wake_requests(mdsc, &s->s_waiting);
3101                                 __unregister_session(mdsc, s);
3102                         } else {
3103                                 /* just close it */
3104                                 mutex_unlock(&mdsc->mutex);
3105                                 mutex_lock(&s->s_mutex);
3106                                 mutex_lock(&mdsc->mutex);
3107                                 ceph_con_close(&s->s_con);
3108                                 mutex_unlock(&s->s_mutex);
3109                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
3110                         }
3111                 } else if (oldstate == newstate) {
3112                         continue;  /* nothing new with this mds */
3113                 }
3114
3115                 /*
3116                  * send reconnect?
3117                  */
3118                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3119                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3120                         mutex_unlock(&mdsc->mutex);
3121                         send_mds_reconnect(mdsc, s);
3122                         mutex_lock(&mdsc->mutex);
3123                 }
3124
3125                 /*
3126                  * kick request on any mds that has gone active.
3127                  */
3128                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3129                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3130                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3131                             oldstate != CEPH_MDS_STATE_STARTING)
3132                                 pr_info("mds%d recovery completed\n", s->s_mds);
3133                         kick_requests(mdsc, i);
3134                         ceph_kick_flushing_caps(mdsc, s);
3135                         wake_up_session_caps(s, 1);
3136                 }
3137         }
3138
3139         for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3140                 s = mdsc->sessions[i];
3141                 if (!s)
3142                         continue;
3143                 if (!ceph_mdsmap_is_laggy(newmap, i))
3144                         continue;
3145                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3146                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3147                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3148                         dout(" connecting to export targets of laggy mds%d\n",
3149                              i);
3150                         __open_export_target_sessions(mdsc, s);
3151                 }
3152         }
3153 }
3154
3155
3156
3157 /*
3158  * leases
3159  */
3160
3161 /*
3162  * caller must hold session s_mutex, dentry->d_lock
3163  */
3164 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3165 {
3166         struct ceph_dentry_info *di = ceph_dentry(dentry);
3167
3168         ceph_put_mds_session(di->lease_session);
3169         di->lease_session = NULL;
3170 }
3171
3172 static void handle_lease(struct ceph_mds_client *mdsc,
3173                          struct ceph_mds_session *session,
3174                          struct ceph_msg *msg)
3175 {
3176         struct super_block *sb = mdsc->fsc->sb;
3177         struct inode *inode;
3178         struct dentry *parent, *dentry;
3179         struct ceph_dentry_info *di;
3180         int mds = session->s_mds;
3181         struct ceph_mds_lease *h = msg->front.iov_base;
3182         u32 seq;
3183         struct ceph_vino vino;
3184         struct qstr dname;
3185         int release = 0;
3186
3187         dout("handle_lease from mds%d\n", mds);
3188
3189         /* decode */
3190         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3191                 goto bad;
3192         vino.ino = le64_to_cpu(h->ino);
3193         vino.snap = CEPH_NOSNAP;
3194         seq = le32_to_cpu(h->seq);
3195         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3196         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3197         if (dname.len != get_unaligned_le32(h+1))
3198                 goto bad;
3199
3200         /* lookup inode */
3201         inode = ceph_find_inode(sb, vino);
3202         dout("handle_lease %s, ino %llx %p %.*s\n",
3203              ceph_lease_op_name(h->action), vino.ino, inode,
3204              dname.len, dname.name);
3205
3206         mutex_lock(&session->s_mutex);
3207         session->s_seq++;
3208
3209         if (inode == NULL) {
3210                 dout("handle_lease no inode %llx\n", vino.ino);
3211                 goto release;
3212         }
3213
3214         /* dentry */
3215         parent = d_find_alias(inode);
3216         if (!parent) {
3217                 dout("no parent dentry on inode %p\n", inode);
3218                 WARN_ON(1);
3219                 goto release;  /* hrm... */
3220         }
3221         dname.hash = full_name_hash(dname.name, dname.len);
3222         dentry = d_lookup(parent, &dname);
3223         dput(parent);
3224         if (!dentry)
3225                 goto release;
3226
3227         spin_lock(&dentry->d_lock);
3228         di = ceph_dentry(dentry);
3229         switch (h->action) {
3230         case CEPH_MDS_LEASE_REVOKE:
3231                 if (di->lease_session == session) {
3232                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3233                                 h->seq = cpu_to_le32(di->lease_seq);
3234                         __ceph_mdsc_drop_dentry_lease(dentry);
3235                 }
3236                 release = 1;
3237                 break;
3238
3239         case CEPH_MDS_LEASE_RENEW:
3240                 if (di->lease_session == session &&
3241                     di->lease_gen == session->s_cap_gen &&
3242                     di->lease_renew_from &&
3243                     di->lease_renew_after == 0) {
3244                         unsigned long duration =
3245                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3246
3247                         di->lease_seq = seq;
3248                         dentry->d_time = di->lease_renew_from + duration;
3249                         di->lease_renew_after = di->lease_renew_from +
3250                                 (duration >> 1);
3251                         di->lease_renew_from = 0;
3252                 }
3253                 break;
3254         }
3255         spin_unlock(&dentry->d_lock);
3256         dput(dentry);
3257
3258         if (!release)
3259                 goto out;
3260
3261 release:
3262         /* let's just reuse the same message */
3263         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3264         ceph_msg_get(msg);
3265         ceph_con_send(&session->s_con, msg);
3266
3267 out:
3268         iput(inode);
3269         mutex_unlock(&session->s_mutex);
3270         return;
3271
3272 bad:
3273         pr_err("corrupt lease message\n");
3274         ceph_msg_dump(msg);
3275 }
3276
3277 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3278                               struct inode *inode,
3279                               struct dentry *dentry, char action,
3280                               u32 seq)
3281 {
3282         struct ceph_msg *msg;
3283         struct ceph_mds_lease *lease;
3284         int len = sizeof(*lease) + sizeof(u32);
3285         int dnamelen = 0;
3286
3287         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3288              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3289         dnamelen = dentry->d_name.len;
3290         len += dnamelen;
3291
3292         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3293         if (!msg)
3294                 return;
3295         lease = msg->front.iov_base;
3296         lease->action = action;
3297         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3298         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3299         lease->seq = cpu_to_le32(seq);
3300         put_unaligned_le32(dnamelen, lease + 1);
3301         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3302
3303         /*
3304          * if this is a preemptive lease RELEASE, no need to
3305          * flush request stream, since the actual request will
3306          * soon follow.
3307          */
3308         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3309
3310         ceph_con_send(&session->s_con, msg);
3311 }
3312
3313 /*
3314  * Preemptively release a lease we expect to invalidate anyway.
3315  * Pass @inode always, @dentry is optional.
3316  */
3317 void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
3318                              struct dentry *dentry)
3319 {
3320         struct ceph_dentry_info *di;
3321         struct ceph_mds_session *session;
3322         u32 seq;
3323
3324         BUG_ON(inode == NULL);
3325         BUG_ON(dentry == NULL);
3326
3327         /* is dentry lease valid? */
3328         spin_lock(&dentry->d_lock);
3329         di = ceph_dentry(dentry);
3330         if (!di || !di->lease_session ||
3331             di->lease_session->s_mds < 0 ||
3332             di->lease_gen != di->lease_session->s_cap_gen ||
3333             !time_before(jiffies, dentry->d_time)) {
3334                 dout("lease_release inode %p dentry %p -- "
3335                      "no lease\n",
3336                      inode, dentry);
3337                 spin_unlock(&dentry->d_lock);
3338                 return;
3339         }
3340
3341         /* we do have a lease on this dentry; note mds and seq */
3342         session = ceph_get_mds_session(di->lease_session);
3343         seq = di->lease_seq;
3344         __ceph_mdsc_drop_dentry_lease(dentry);
3345         spin_unlock(&dentry->d_lock);
3346
3347         dout("lease_release inode %p dentry %p to mds%d\n",
3348              inode, dentry, session->s_mds);
3349         ceph_mdsc_lease_send_msg(session, inode, dentry,
3350                                  CEPH_MDS_LEASE_RELEASE, seq);
3351         ceph_put_mds_session(session);
3352 }
3353
3354 /*
3355  * drop all leases (and dentry refs) in preparation for umount
3356  */
3357 static void drop_leases(struct ceph_mds_client *mdsc)
3358 {
3359         int i;
3360
3361         dout("drop_leases\n");
3362         mutex_lock(&mdsc->mutex);
3363         for (i = 0; i < mdsc->max_sessions; i++) {
3364                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3365                 if (!s)
3366                         continue;
3367                 mutex_unlock(&mdsc->mutex);
3368                 mutex_lock(&s->s_mutex);
3369                 mutex_unlock(&s->s_mutex);
3370                 ceph_put_mds_session(s);
3371                 mutex_lock(&mdsc->mutex);
3372         }
3373         mutex_unlock(&mdsc->mutex);
3374 }
3375
3376
3377
3378 /*
3379  * delayed work -- periodically trim expired leases, renew caps with mds
3380  */
3381 static void schedule_delayed(struct ceph_mds_client *mdsc)
3382 {
3383         int delay = 5;
3384         unsigned hz = round_jiffies_relative(HZ * delay);
3385         schedule_delayed_work(&mdsc->delayed_work, hz);
3386 }
3387
3388 static void delayed_work(struct work_struct *work)
3389 {
3390         int i;
3391         struct ceph_mds_client *mdsc =
3392                 container_of(work, struct ceph_mds_client, delayed_work.work);
3393         int renew_interval;
3394         int renew_caps;
3395
3396         dout("mdsc delayed_work\n");
3397         ceph_check_delayed_caps(mdsc);
3398
3399         mutex_lock(&mdsc->mutex);
3400         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3401         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3402                                    mdsc->last_renew_caps);
3403         if (renew_caps)
3404                 mdsc->last_renew_caps = jiffies;
3405
3406         for (i = 0; i < mdsc->max_sessions; i++) {
3407                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3408                 if (s == NULL)
3409                         continue;
3410                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3411                         dout("resending session close request for mds%d\n",
3412                              s->s_mds);
3413                         request_close_session(mdsc, s);
3414                         ceph_put_mds_session(s);
3415                         continue;
3416                 }
3417                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3418                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3419                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3420                                 pr_info("mds%d hung\n", s->s_mds);
3421                         }
3422                 }
3423                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3424                         /* this mds is failed or recovering, just wait */
3425                         ceph_put_mds_session(s);
3426                         continue;
3427                 }
3428                 mutex_unlock(&mdsc->mutex);
3429
3430                 mutex_lock(&s->s_mutex);
3431                 if (renew_caps)
3432                         send_renew_caps(mdsc, s);
3433                 else
3434                         ceph_con_keepalive(&s->s_con);
3435                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3436                     s->s_state == CEPH_MDS_SESSION_HUNG)
3437                         ceph_send_cap_releases(mdsc, s);
3438                 mutex_unlock(&s->s_mutex);
3439                 ceph_put_mds_session(s);
3440
3441                 mutex_lock(&mdsc->mutex);
3442         }
3443         mutex_unlock(&mdsc->mutex);
3444
3445         schedule_delayed(mdsc);
3446 }
3447
3448 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3449
3450 {
3451         struct ceph_mds_client *mdsc;
3452
3453         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3454         if (!mdsc)
3455                 return -ENOMEM;
3456         mdsc->fsc = fsc;
3457         fsc->mdsc = mdsc;
3458         mutex_init(&mdsc->mutex);
3459         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3460         if (mdsc->mdsmap == NULL) {
3461                 kfree(mdsc);
3462                 return -ENOMEM;
3463         }
3464
3465         init_completion(&mdsc->safe_umount_waiters);
3466         init_waitqueue_head(&mdsc->session_close_wq);
3467         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3468         mdsc->sessions = NULL;
3469         atomic_set(&mdsc->num_sessions, 0);
3470         mdsc->max_sessions = 0;
3471         mdsc->stopping = 0;
3472         mdsc->last_snap_seq = 0;
3473         init_rwsem(&mdsc->snap_rwsem);
3474         mdsc->snap_realms = RB_ROOT;
3475         INIT_LIST_HEAD(&mdsc->snap_empty);
3476         spin_lock_init(&mdsc->snap_empty_lock);
3477         mdsc->last_tid = 0;
3478         mdsc->oldest_tid = 0;
3479         mdsc->request_tree = RB_ROOT;
3480         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3481         mdsc->last_renew_caps = jiffies;
3482         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3483         spin_lock_init(&mdsc->cap_delay_lock);
3484         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3485         spin_lock_init(&mdsc->snap_flush_lock);
3486         mdsc->last_cap_flush_tid = 1;
3487         mdsc->cap_flush_tree = RB_ROOT;
3488         INIT_LIST_HEAD(&mdsc->cap_dirty);
3489         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3490         mdsc->num_cap_flushing = 0;
3491         spin_lock_init(&mdsc->cap_dirty_lock);
3492         init_waitqueue_head(&mdsc->cap_flushing_wq);
3493         spin_lock_init(&mdsc->dentry_lru_lock);
3494         INIT_LIST_HEAD(&mdsc->dentry_lru);
3495
3496         ceph_caps_init(mdsc);
3497         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3498
3499         init_rwsem(&mdsc->pool_perm_rwsem);
3500         mdsc->pool_perm_tree = RB_ROOT;
3501
3502         return 0;
3503 }
3504
3505 /*
3506  * Wait for safe replies on open mds requests.  If we time out, drop
3507  * all requests from the tree to avoid dangling dentry refs.
3508  */
3509 static void wait_requests(struct ceph_mds_client *mdsc)
3510 {
3511         struct ceph_options *opts = mdsc->fsc->client->options;
3512         struct ceph_mds_request *req;
3513
3514         mutex_lock(&mdsc->mutex);
3515         if (__get_oldest_req(mdsc)) {
3516                 mutex_unlock(&mdsc->mutex);
3517
3518                 dout("wait_requests waiting for requests\n");
3519                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3520                                     ceph_timeout_jiffies(opts->mount_timeout));
3521
3522                 /* tear down remaining requests */
3523                 mutex_lock(&mdsc->mutex);
3524                 while ((req = __get_oldest_req(mdsc))) {
3525                         dout("wait_requests timed out on tid %llu\n",
3526                              req->r_tid);
3527                         __unregister_request(mdsc, req);
3528                 }
3529         }
3530         mutex_unlock(&mdsc->mutex);
3531         dout("wait_requests done\n");
3532 }
3533
3534 /*
3535  * called before mount is ro, and before dentries are torn down.
3536  * (hmm, does this still race with new lookups?)
3537  */
3538 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3539 {
3540         dout("pre_umount\n");
3541         mdsc->stopping = 1;
3542
3543         drop_leases(mdsc);
3544         ceph_flush_dirty_caps(mdsc);
3545         wait_requests(mdsc);
3546
3547         /*
3548          * wait for reply handlers to drop their request refs and
3549          * their inode/dcache refs
3550          */
3551         ceph_msgr_flush();
3552 }
3553
3554 /*
3555  * wait for all write mds requests to flush.
3556  */
3557 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3558 {
3559         struct ceph_mds_request *req = NULL, *nextreq;
3560         struct rb_node *n;
3561
3562         mutex_lock(&mdsc->mutex);
3563         dout("wait_unsafe_requests want %lld\n", want_tid);
3564 restart:
3565         req = __get_oldest_req(mdsc);
3566         while (req && req->r_tid <= want_tid) {
3567                 /* find next request */
3568                 n = rb_next(&req->r_node);
3569                 if (n)
3570                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3571                 else
3572                         nextreq = NULL;
3573                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
3574                     (req->r_op & CEPH_MDS_OP_WRITE)) {
3575                         /* write op */
3576                         ceph_mdsc_get_request(req);
3577                         if (nextreq)
3578                                 ceph_mdsc_get_request(nextreq);
3579                         mutex_unlock(&mdsc->mutex);
3580                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3581                              req->r_tid, want_tid);
3582                         wait_for_completion(&req->r_safe_completion);
3583                         mutex_lock(&mdsc->mutex);
3584                         ceph_mdsc_put_request(req);
3585                         if (!nextreq)
3586                                 break;  /* next dne before, so we're done! */
3587                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3588                                 /* next request was removed from tree */
3589                                 ceph_mdsc_put_request(nextreq);
3590                                 goto restart;
3591                         }
3592                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3593                 }
3594                 req = nextreq;
3595         }
3596         mutex_unlock(&mdsc->mutex);
3597         dout("wait_unsafe_requests done\n");
3598 }
3599
3600 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3601 {
3602         u64 want_tid, want_flush, want_snap;
3603
3604         if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
3605                 return;
3606
3607         dout("sync\n");
3608         mutex_lock(&mdsc->mutex);
3609         want_tid = mdsc->last_tid;
3610         mutex_unlock(&mdsc->mutex);
3611
3612         ceph_flush_dirty_caps(mdsc);
3613         spin_lock(&mdsc->cap_dirty_lock);
3614         want_flush = mdsc->last_cap_flush_tid;
3615         spin_unlock(&mdsc->cap_dirty_lock);
3616
3617         down_read(&mdsc->snap_rwsem);
3618         want_snap = mdsc->last_snap_seq;
3619         up_read(&mdsc->snap_rwsem);
3620
3621         dout("sync want tid %lld flush_seq %lld snap_seq %lld\n",
3622              want_tid, want_flush, want_snap);
3623
3624         wait_unsafe_requests(mdsc, want_tid);
3625         wait_caps_flush(mdsc, want_flush, want_snap);
3626 }
3627
3628 /*
3629  * true if all sessions are closed, or we force unmount
3630  */
3631 static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3632 {
3633         if (ACCESS_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
3634                 return true;
3635         return atomic_read(&mdsc->num_sessions) == 0;
3636 }
3637
3638 /*
3639  * called after sb is ro.
3640  */
3641 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3642 {
3643         struct ceph_options *opts = mdsc->fsc->client->options;
3644         struct ceph_mds_session *session;
3645         int i;
3646
3647         dout("close_sessions\n");
3648
3649         /* close sessions */
3650         mutex_lock(&mdsc->mutex);
3651         for (i = 0; i < mdsc->max_sessions; i++) {
3652                 session = __ceph_lookup_mds_session(mdsc, i);
3653                 if (!session)
3654                         continue;
3655                 mutex_unlock(&mdsc->mutex);
3656                 mutex_lock(&session->s_mutex);
3657                 __close_session(mdsc, session);
3658                 mutex_unlock(&session->s_mutex);
3659                 ceph_put_mds_session(session);
3660                 mutex_lock(&mdsc->mutex);
3661         }
3662         mutex_unlock(&mdsc->mutex);
3663
3664         dout("waiting for sessions to close\n");
3665         wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3666                            ceph_timeout_jiffies(opts->mount_timeout));
3667
3668         /* tear down remaining sessions */
3669         mutex_lock(&mdsc->mutex);
3670         for (i = 0; i < mdsc->max_sessions; i++) {
3671                 if (mdsc->sessions[i]) {
3672                         session = get_session(mdsc->sessions[i]);
3673                         __unregister_session(mdsc, session);
3674                         mutex_unlock(&mdsc->mutex);
3675                         mutex_lock(&session->s_mutex);
3676                         remove_session_caps(session);
3677                         mutex_unlock(&session->s_mutex);
3678                         ceph_put_mds_session(session);
3679                         mutex_lock(&mdsc->mutex);
3680                 }
3681         }
3682         WARN_ON(!list_empty(&mdsc->cap_delay_list));
3683         mutex_unlock(&mdsc->mutex);
3684
3685         ceph_cleanup_empty_realms(mdsc);
3686
3687         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3688
3689         dout("stopped\n");
3690 }
3691
3692 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
3693 {
3694         struct ceph_mds_session *session;
3695         int mds;
3696
3697         dout("force umount\n");
3698
3699         mutex_lock(&mdsc->mutex);
3700         for (mds = 0; mds < mdsc->max_sessions; mds++) {
3701                 session = __ceph_lookup_mds_session(mdsc, mds);
3702                 if (!session)
3703                         continue;
3704                 mutex_unlock(&mdsc->mutex);
3705                 mutex_lock(&session->s_mutex);
3706                 __close_session(mdsc, session);
3707                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
3708                         cleanup_session_requests(mdsc, session);
3709                         remove_session_caps(session);
3710                 }
3711                 mutex_unlock(&session->s_mutex);
3712                 ceph_put_mds_session(session);
3713                 mutex_lock(&mdsc->mutex);
3714                 kick_requests(mdsc, mds);
3715         }
3716         __wake_requests(mdsc, &mdsc->waiting_for_map);
3717         mutex_unlock(&mdsc->mutex);
3718 }
3719
3720 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3721 {
3722         dout("stop\n");
3723         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3724         if (mdsc->mdsmap)
3725                 ceph_mdsmap_destroy(mdsc->mdsmap);
3726         kfree(mdsc->sessions);
3727         ceph_caps_finalize(mdsc);
3728         ceph_pool_perm_destroy(mdsc);
3729 }
3730
3731 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3732 {
3733         struct ceph_mds_client *mdsc = fsc->mdsc;
3734
3735         dout("mdsc_destroy %p\n", mdsc);
3736         ceph_mdsc_stop(mdsc);
3737
3738         /* flush out any connection work with references to us */
3739         ceph_msgr_flush();
3740
3741         fsc->mdsc = NULL;
3742         kfree(mdsc);
3743         dout("mdsc_destroy %p done\n", mdsc);
3744 }
3745
3746
3747 /*
3748  * handle mds map update.
3749  */
3750 void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3751 {
3752         u32 epoch;
3753         u32 maplen;
3754         void *p = msg->front.iov_base;
3755         void *end = p + msg->front.iov_len;
3756         struct ceph_mdsmap *newmap, *oldmap;
3757         struct ceph_fsid fsid;
3758         int err = -EINVAL;
3759
3760         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3761         ceph_decode_copy(&p, &fsid, sizeof(fsid));
3762         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3763                 return;
3764         epoch = ceph_decode_32(&p);
3765         maplen = ceph_decode_32(&p);
3766         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3767
3768         /* do we need it? */
3769         mutex_lock(&mdsc->mutex);
3770         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3771                 dout("handle_map epoch %u <= our %u\n",
3772                      epoch, mdsc->mdsmap->m_epoch);
3773                 mutex_unlock(&mdsc->mutex);
3774                 return;
3775         }
3776
3777         newmap = ceph_mdsmap_decode(&p, end);
3778         if (IS_ERR(newmap)) {
3779                 err = PTR_ERR(newmap);
3780                 goto bad_unlock;
3781         }
3782
3783         /* swap into place */
3784         if (mdsc->mdsmap) {
3785                 oldmap = mdsc->mdsmap;
3786                 mdsc->mdsmap = newmap;
3787                 check_new_map(mdsc, newmap, oldmap);
3788                 ceph_mdsmap_destroy(oldmap);
3789         } else {
3790                 mdsc->mdsmap = newmap;  /* first mds map */
3791         }
3792         mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3793
3794         __wake_requests(mdsc, &mdsc->waiting_for_map);
3795         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
3796                           mdsc->mdsmap->m_epoch);
3797
3798         mutex_unlock(&mdsc->mutex);
3799         schedule_delayed(mdsc);
3800         return;
3801
3802 bad_unlock:
3803         mutex_unlock(&mdsc->mutex);
3804 bad:
3805         pr_err("error decoding mdsmap %d\n", err);
3806         return;
3807 }
3808
3809 static struct ceph_connection *con_get(struct ceph_connection *con)
3810 {
3811         struct ceph_mds_session *s = con->private;
3812
3813         if (get_session(s)) {
3814                 dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3815                 return con;
3816         }
3817         dout("mdsc con_get %p FAIL\n", s);
3818         return NULL;
3819 }
3820
3821 static void con_put(struct ceph_connection *con)
3822 {
3823         struct ceph_mds_session *s = con->private;
3824
3825         dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3826         ceph_put_mds_session(s);
3827 }
3828
3829 /*
3830  * if the client is unresponsive for long enough, the mds will kill
3831  * the session entirely.
3832  */
3833 static void peer_reset(struct ceph_connection *con)
3834 {
3835         struct ceph_mds_session *s = con->private;
3836         struct ceph_mds_client *mdsc = s->s_mdsc;
3837
3838         pr_warn("mds%d closed our session\n", s->s_mds);
3839         send_mds_reconnect(mdsc, s);
3840 }
3841
3842 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3843 {
3844         struct ceph_mds_session *s = con->private;
3845         struct ceph_mds_client *mdsc = s->s_mdsc;
3846         int type = le16_to_cpu(msg->hdr.type);
3847
3848         mutex_lock(&mdsc->mutex);
3849         if (__verify_registered_session(mdsc, s) < 0) {
3850                 mutex_unlock(&mdsc->mutex);
3851                 goto out;
3852         }
3853         mutex_unlock(&mdsc->mutex);
3854
3855         switch (type) {
3856         case CEPH_MSG_MDS_MAP:
3857                 ceph_mdsc_handle_map(mdsc, msg);
3858                 break;
3859         case CEPH_MSG_CLIENT_SESSION:
3860                 handle_session(s, msg);
3861                 break;
3862         case CEPH_MSG_CLIENT_REPLY:
3863                 handle_reply(s, msg);
3864                 break;
3865         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3866                 handle_forward(mdsc, s, msg);
3867                 break;
3868         case CEPH_MSG_CLIENT_CAPS:
3869                 ceph_handle_caps(s, msg);
3870                 break;
3871         case CEPH_MSG_CLIENT_SNAP:
3872                 ceph_handle_snap(mdsc, s, msg);
3873                 break;
3874         case CEPH_MSG_CLIENT_LEASE:
3875                 handle_lease(mdsc, s, msg);
3876                 break;
3877
3878         default:
3879                 pr_err("received unknown message type %d %s\n", type,
3880                        ceph_msg_type_name(type));
3881         }
3882 out:
3883         ceph_msg_put(msg);
3884 }
3885
3886 /*
3887  * authentication
3888  */
3889
3890 /*
3891  * Note: returned pointer is the address of a structure that's
3892  * managed separately.  Caller must *not* attempt to free it.
3893  */
3894 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3895                                         int *proto, int force_new)
3896 {
3897         struct ceph_mds_session *s = con->private;
3898         struct ceph_mds_client *mdsc = s->s_mdsc;
3899         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3900         struct ceph_auth_handshake *auth = &s->s_auth;
3901
3902         if (force_new && auth->authorizer) {
3903                 ceph_auth_destroy_authorizer(ac, auth->authorizer);
3904                 auth->authorizer = NULL;
3905         }
3906         if (!auth->authorizer) {
3907                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3908                                                       auth);
3909                 if (ret)
3910                         return ERR_PTR(ret);
3911         } else {
3912                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3913                                                       auth);
3914                 if (ret)
3915                         return ERR_PTR(ret);
3916         }
3917         *proto = ac->protocol;
3918
3919         return auth;
3920 }
3921
3922
3923 static int verify_authorizer_reply(struct ceph_connection *con, int len)
3924 {
3925         struct ceph_mds_session *s = con->private;
3926         struct ceph_mds_client *mdsc = s->s_mdsc;
3927         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3928
3929         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3930 }
3931
3932 static int invalidate_authorizer(struct ceph_connection *con)
3933 {
3934         struct ceph_mds_session *s = con->private;
3935         struct ceph_mds_client *mdsc = s->s_mdsc;
3936         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3937
3938         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3939
3940         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3941 }
3942
3943 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3944                                 struct ceph_msg_header *hdr, int *skip)
3945 {
3946         struct ceph_msg *msg;
3947         int type = (int) le16_to_cpu(hdr->type);
3948         int front_len = (int) le32_to_cpu(hdr->front_len);
3949
3950         if (con->in_msg)
3951                 return con->in_msg;
3952
3953         *skip = 0;
3954         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3955         if (!msg) {
3956                 pr_err("unable to allocate msg type %d len %d\n",
3957                        type, front_len);
3958                 return NULL;
3959         }
3960
3961         return msg;
3962 }
3963
3964 static int mds_sign_message(struct ceph_msg *msg)
3965 {
3966        struct ceph_mds_session *s = msg->con->private;
3967        struct ceph_auth_handshake *auth = &s->s_auth;
3968
3969        return ceph_auth_sign_message(auth, msg);
3970 }
3971
3972 static int mds_check_message_signature(struct ceph_msg *msg)
3973 {
3974        struct ceph_mds_session *s = msg->con->private;
3975        struct ceph_auth_handshake *auth = &s->s_auth;
3976
3977        return ceph_auth_check_message_signature(auth, msg);
3978 }
3979
3980 static const struct ceph_connection_operations mds_con_ops = {
3981         .get = con_get,
3982         .put = con_put,
3983         .dispatch = dispatch,
3984         .get_authorizer = get_authorizer,
3985         .verify_authorizer_reply = verify_authorizer_reply,
3986         .invalidate_authorizer = invalidate_authorizer,
3987         .peer_reset = peer_reset,
3988         .alloc_msg = mds_alloc_msg,
3989         .sign_message = mds_sign_message,
3990         .check_message_signature = mds_check_message_signature,
3991 };
3992
3993 /* eof */