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  45  * are no longer valid.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