fs/ceph/mds_client.c

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  45  * are no longer valid.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