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  41  * are no longer valid.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