fs/ceph/mds_client.c

   1 #include <linux/ceph/ceph_debug.h>
   2
   3 #include <linux/fs.h>
   4 #include <linux/wait.h>
   5 #include <linux/slab.h>
   6 #include <linux/gfp.h>
   7 #include <linux/sched.h>
   8 #include <linux/debugfs.h>
   9 #include <linux/seq_file.h>
  10 #include <linux/utsname.h>
  11 #include <linux/ratelimit.h>
  12
  13 #include "super.h"
  14 #include "mds_client.h"
  15
  16 #include <linux/ceph/ceph_features.h>
  17 #include <linux/ceph/messenger.h>
  18 #include <linux/ceph/decode.h>
  19 #include <linux/ceph/pagelist.h>
  20 #include <linux/ceph/auth.h>
  21 #include <linux/ceph/debugfs.h>
  22
  23 /*
  24  * A cluster of MDS (metadata server) daemons is responsible for
  25  * managing the file system namespace (the directory hierarchy and
  26  * inodes) and for coordinating shared access to storage.  Metadata is
  27  * partitioning hierarchically across a number of servers, and that
  28  * partition varies over time as the cluster adjusts the distribution
  29  * in order to balance load.
  30  *
  31  * The MDS client is primarily responsible to managing synchronous
  32  * metadata requests for operations like open, unlink, and so forth.
  33  * If there is a MDS failure, we find out about it when we (possibly
  34  * request and) receive a new MDS map, and can resubmit affected
  35  * requests.
  36  *
  37  * For the most part, though, we take advantage of a lossless
  38  * communications channel to the MDS, and do not need to worry about
  39  * timing out or resubmitting requests.
  40  *
  41  * We maintain a stateful "session" with each MDS we interact with.
  42  * Within each session, we sent periodic heartbeat messages to ensure
  43  * any capabilities or leases we have been issues remain valid.  If
  44  * the session times out and goes stale, our leases and capabilities
  45  * are no longer valid.
  46  */
  47
  48 struct ceph_reconnect_state {
  49         int nr_caps;
  50         struct ceph_pagelist *pagelist;
  51         bool flock;
  52 };
  53
  54 static void __wake_requests(struct ceph_mds_client *mdsc,
  55                             struct list_head *head);
  56
  57 static const struct ceph_connection_operations mds_con_ops;
  58
  59
  60 /*
  61  * mds reply parsing
  62  */
  63
  64 /*
  65  * parse individual inode info
  66  */
  67 static int parse_reply_info_in(void **p, void *end,
  68                                struct ceph_mds_reply_info_in *info,
  69                                u64 features)
  70 {
  71         int err = -EIO;
  72
  73         info->in = *p;
  74         *p += sizeof(struct ceph_mds_reply_inode) +
  75                 sizeof(*info->in->fragtree.splits) *
  76                 le32_to_cpu(info->in->fragtree.nsplits);
  77
  78         ceph_decode_32_safe(p, end, info->symlink_len, bad);
  79         ceph_decode_need(p, end, info->symlink_len, bad);
  80         info->symlink = *p;
  81         *p += info->symlink_len;
  82
  83         if (features & CEPH_FEATURE_DIRLAYOUTHASH)
  84                 ceph_decode_copy_safe(p, end, &info->dir_layout,
  85                                       sizeof(info->dir_layout), bad);
  86         else
  87                 memset(&info->dir_layout, 0, sizeof(info->dir_layout));
  88
  89         ceph_decode_32_safe(p, end, info->xattr_len, bad);
  90         ceph_decode_need(p, end, info->xattr_len, bad);
  91         info->xattr_data = *p;
  92         *p += info->xattr_len;
  93
  94         if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
  95                 ceph_decode_64_safe(p, end, info->inline_version, bad);
  96                 ceph_decode_32_safe(p, end, info->inline_len, bad);
  97                 ceph_decode_need(p, end, info->inline_len, bad);
  98                 info->inline_data = *p;
  99                 *p += info->inline_len;
 100         } else
 101                 info->inline_version = CEPH_INLINE_NONE;
 102
 103         return 0;
 104 bad:
 105         return err;
 106 }
 107
 108 /*
 109  * parse a normal reply, which may contain a (dir+)dentry and/or a
 110  * target inode.
 111  */
 112 static int parse_reply_info_trace(void **p, void *end,
 113                                   struct ceph_mds_reply_info_parsed *info,
 114                                   u64 features)
 115 {
 116         int err;
 117
 118         if (info->head->is_dentry) {
 119                 err = parse_reply_info_in(p, end, &info->diri, features);
 120                 if (err < 0)
 121                         goto out_bad;
 122
 123                 if (unlikely(*p + sizeof(*info->dirfrag) > end))
 124                         goto bad;
 125                 info->dirfrag = *p;
 126                 *p += sizeof(*info->dirfrag) +
 127                         sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 128                 if (unlikely(*p > end))
 129                         goto bad;
 130
 131                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 132                 ceph_decode_need(p, end, info->dname_len, bad);
 133                 info->dname = *p;
 134                 *p += info->dname_len;
 135                 info->dlease = *p;
 136                 *p += sizeof(*info->dlease);
 137         }
 138
 139         if (info->head->is_target) {
 140                 err = parse_reply_info_in(p, end, &info->targeti, features);
 141                 if (err < 0)
 142                         goto out_bad;
 143         }
 144
 145         if (unlikely(*p != end))
 146                 goto bad;
 147         return 0;
 148
 149 bad:
 150         err = -EIO;
 151 out_bad:
 152         pr_err("problem parsing mds trace %d\n", err);
 153         return err;
 154 }
 155
 156 /*
 157  * parse readdir results
 158  */
 159 static int parse_reply_info_dir(void **p, void *end,
 160                                 struct ceph_mds_reply_info_parsed *info,
 161                                 u64 features)
 162 {
 163         u32 num, i = 0;
 164         int err;
 165
 166         info->dir_dir = *p;
 167         if (*p + sizeof(*info->dir_dir) > end)
 168                 goto bad;
 169         *p += sizeof(*info->dir_dir) +
 170                 sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 171         if (*p > end)
 172                 goto bad;
 173
 174         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 175         num = ceph_decode_32(p);
 176         info->dir_end = ceph_decode_8(p);
 177         info->dir_complete = ceph_decode_8(p);
 178         if (num == 0)
 179                 goto done;
 180
 181         BUG_ON(!info->dir_in);
 182         info->dir_dname = (void *)(info->dir_in + num);
 183         info->dir_dname_len = (void *)(info->dir_dname + num);
 184         info->dir_dlease = (void *)(info->dir_dname_len + num);
 185         if ((unsigned long)(info->dir_dlease + num) >
 186             (unsigned long)info->dir_in + info->dir_buf_size) {
 187                 pr_err("dir contents are larger than expected\n");
 188                 WARN_ON(1);
 189                 goto bad;
 190         }
 191
 192         info->dir_nr = num;
 193         while (num) {
 194                 /* dentry */
 195                 ceph_decode_need(p, end, sizeof(u32)*2, bad);
 196                 info->dir_dname_len[i] = ceph_decode_32(p);
 197                 ceph_decode_need(p, end, info->dir_dname_len[i], bad);
 198                 info->dir_dname[i] = *p;
 199                 *p += info->dir_dname_len[i];
 200                 dout("parsed dir dname '%.*s'\n", info->dir_dname_len[i],
 201                      info->dir_dname[i]);
 202                 info->dir_dlease[i] = *p;
 203                 *p += sizeof(struct ceph_mds_reply_lease);
 204
 205                 /* inode */
 206                 err = parse_reply_info_in(p, end, &info->dir_in[i], features);
 207                 if (err < 0)
 208                         goto out_bad;
 209                 i++;
 210                 num--;
 211         }
 212
 213 done:
 214         if (*p != end)
 215                 goto bad;
 216         return 0;
 217
 218 bad:
 219         err = -EIO;
 220 out_bad:
 221         pr_err("problem parsing dir contents %d\n", err);
 222         return err;
 223 }
 224
 225 /*
 226  * parse fcntl F_GETLK results
 227  */
 228 static int parse_reply_info_filelock(void **p, void *end,
 229                                      struct ceph_mds_reply_info_parsed *info,
 230                                      u64 features)
 231 {
 232         if (*p + sizeof(*info->filelock_reply) > end)
 233                 goto bad;
 234
 235         info->filelock_reply = *p;
 236         *p += sizeof(*info->filelock_reply);
 237
 238         if (unlikely(*p != end))
 239                 goto bad;
 240         return 0;
 241
 242 bad:
 243         return -EIO;
 244 }
 245
 246 /*
 247  * parse create results
 248  */
 249 static int parse_reply_info_create(void **p, void *end,
 250                                   struct ceph_mds_reply_info_parsed *info,
 251                                   u64 features)
 252 {
 253         if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 254                 if (*p == end) {
 255                         info->has_create_ino = false;
 256                 } else {
 257                         info->has_create_ino = true;
 258                         info->ino = ceph_decode_64(p);
 259                 }
 260         }
 261
 262         if (unlikely(*p != end))
 263                 goto bad;
 264         return 0;
 265
 266 bad:
 267         return -EIO;
 268 }
 269
 270 /*
 271  * parse extra results
 272  */
 273 static int parse_reply_info_extra(void **p, void *end,
 274                                   struct ceph_mds_reply_info_parsed *info,
 275                                   u64 features)
 276 {
 277         if (info->head->op == CEPH_MDS_OP_GETFILELOCK)
 278                 return parse_reply_info_filelock(p, end, info, features);
 279         else if (info->head->op == CEPH_MDS_OP_READDIR ||
 280                  info->head->op == CEPH_MDS_OP_LSSNAP)
 281                 return parse_reply_info_dir(p, end, info, features);
 282         else if (info->head->op == CEPH_MDS_OP_CREATE)
 283                 return parse_reply_info_create(p, end, info, features);
 284         else
 285                 return -EIO;
 286 }
 287
 288 /*
 289  * parse entire mds reply
 290  */
 291 static int parse_reply_info(struct ceph_msg *msg,
 292                             struct ceph_mds_reply_info_parsed *info,
 293                             u64 features)
 294 {
 295         void *p, *end;
 296         u32 len;
 297         int err;
 298
 299         info->head = msg->front.iov_base;
 300         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 301         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 302
 303         /* trace */
 304         ceph_decode_32_safe(&p, end, len, bad);
 305         if (len > 0) {
 306                 ceph_decode_need(&p, end, len, bad);
 307                 err = parse_reply_info_trace(&p, p+len, info, features);
 308                 if (err < 0)
 309                         goto out_bad;
 310         }
 311
 312         /* extra */
 313         ceph_decode_32_safe(&p, end, len, bad);
 314         if (len > 0) {
 315                 ceph_decode_need(&p, end, len, bad);
 316                 err = parse_reply_info_extra(&p, p+len, info, features);
 317                 if (err < 0)
 318                         goto out_bad;
 319         }
 320
 321         /* snap blob */
 322         ceph_decode_32_safe(&p, end, len, bad);
 323         info->snapblob_len = len;
 324         info->snapblob = p;
 325         p += len;
 326
 327         if (p != end)
 328                 goto bad;
 329         return 0;
 330
 331 bad:
 332         err = -EIO;
 333 out_bad:
 334         pr_err("mds parse_reply err %d\n", err);
 335         return err;
 336 }
 337
 338 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 339 {
 340         if (!info->dir_in)
 341                 return;
 342         free_pages((unsigned long)info->dir_in, get_order(info->dir_buf_size));
 343 }
 344
 345
 346 /*
 347  * sessions
 348  */
 349 const char *ceph_session_state_name(int s)
 350 {
 351         switch (s) {
 352         case CEPH_MDS_SESSION_NEW: return "new";
 353         case CEPH_MDS_SESSION_OPENING: return "opening";
 354         case CEPH_MDS_SESSION_OPEN: return "open";
 355         case CEPH_MDS_SESSION_HUNG: return "hung";
 356         case CEPH_MDS_SESSION_CLOSING: return "closing";
 357         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 358         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 359         default: return "???";
 360         }
 361 }
 362
 363 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 364 {
 365         if (atomic_inc_not_zero(&s->s_ref)) {
 366                 dout("mdsc get_session %p %d -> %d\n", s,
 367                      atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
 368                 return s;
 369         } else {
 370                 dout("mdsc get_session %p 0 -- FAIL", s);
 371                 return NULL;
 372         }
 373 }
 374
 375 void ceph_put_mds_session(struct ceph_mds_session *s)
 376 {
 377         dout("mdsc put_session %p %d -> %d\n", s,
 378              atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
 379         if (atomic_dec_and_test(&s->s_ref)) {
 380                 if (s->s_auth.authorizer)
 381                         ceph_auth_destroy_authorizer(
 382                                 s->s_mdsc->fsc->client->monc.auth,
 383                                 s->s_auth.authorizer);
 384                 kfree(s);
 385         }
 386 }
 387
 388 /*
 389  * called under mdsc->mutex
 390  */
 391 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 392                                                    int mds)
 393 {
 394         struct ceph_mds_session *session;
 395
 396         if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
 397                 return NULL;
 398         session = mdsc->sessions[mds];
 399         dout("lookup_mds_session %p %d\n", session,
 400              atomic_read(&session->s_ref));
 401         get_session(session);
 402         return session;
 403 }
 404
 405 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 406 {
 407         if (mds >= mdsc->max_sessions)
 408                 return false;
 409         return mdsc->sessions[mds];
 410 }
 411
 412 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 413                                        struct ceph_mds_session *s)
 414 {
 415         if (s->s_mds >= mdsc->max_sessions ||
 416             mdsc->sessions[s->s_mds] != s)
 417                 return -ENOENT;
 418         return 0;
 419 }
 420
 421 /*
 422  * create+register a new session for given mds.
 423  * called under mdsc->mutex.
 424  */
 425 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 426                                                  int mds)
 427 {
 428         struct ceph_mds_session *s;
 429
 430         if (mds >= mdsc->mdsmap->m_max_mds)
 431                 return ERR_PTR(-EINVAL);
 432
 433         s = kzalloc(sizeof(*s), GFP_NOFS);
 434         if (!s)
 435                 return ERR_PTR(-ENOMEM);
 436         s->s_mdsc = mdsc;
 437         s->s_mds = mds;
 438         s->s_state = CEPH_MDS_SESSION_NEW;
 439         s->s_ttl = 0;
 440         s->s_seq = 0;
 441         mutex_init(&s->s_mutex);
 442
 443         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 444
 445         spin_lock_init(&s->s_gen_ttl_lock);
 446         s->s_cap_gen = 0;
 447         s->s_cap_ttl = jiffies - 1;
 448
 449         spin_lock_init(&s->s_cap_lock);
 450         s->s_renew_requested = 0;
 451         s->s_renew_seq = 0;
 452         INIT_LIST_HEAD(&s->s_caps);
 453         s->s_nr_caps = 0;
 454         s->s_trim_caps = 0;
 455         atomic_set(&s->s_ref, 1);
 456         INIT_LIST_HEAD(&s->s_waiting);
 457         INIT_LIST_HEAD(&s->s_unsafe);
 458         s->s_num_cap_releases = 0;
 459         s->s_cap_reconnect = 0;
 460         s->s_cap_iterator = NULL;
 461         INIT_LIST_HEAD(&s->s_cap_releases);
 462         INIT_LIST_HEAD(&s->s_cap_flushing);
 463         INIT_LIST_HEAD(&s->s_cap_snaps_flushing);
 464
 465         dout("register_session mds%d\n", mds);
 466         if (mds >= mdsc->max_sessions) {
 467                 int newmax = 1 << get_count_order(mds+1);
 468                 struct ceph_mds_session **sa;
 469
 470                 dout("register_session realloc to %d\n", newmax);
 471                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 472                 if (sa == NULL)
 473                         goto fail_realloc;
 474                 if (mdsc->sessions) {
 475                         memcpy(sa, mdsc->sessions,
 476                                mdsc->max_sessions * sizeof(void *));
 477                         kfree(mdsc->sessions);
 478                 }
 479                 mdsc->sessions = sa;
 480                 mdsc->max_sessions = newmax;
 481         }
 482         mdsc->sessions[mds] = s;
 483         atomic_inc(&mdsc->num_sessions);
 484         atomic_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 485
 486         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 487                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 488
 489         return s;
 490
 491 fail_realloc:
 492         kfree(s);
 493         return ERR_PTR(-ENOMEM);
 494 }
 495
 496 /*
 497  * called under mdsc->mutex
 498  */
 499 static void __unregister_session(struct ceph_mds_client *mdsc,
 500                                struct ceph_mds_session *s)
 501 {
 502         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 503         BUG_ON(mdsc->sessions[s->s_mds] != s);
 504         mdsc->sessions[s->s_mds] = NULL;
 505         ceph_con_close(&s->s_con);
 506         ceph_put_mds_session(s);
 507         atomic_dec(&mdsc->num_sessions);
 508 }
 509
 510 /*
 511  * drop session refs in request.
 512  *
 513  * should be last request ref, or hold mdsc->mutex
 514  */
 515 static void put_request_session(struct ceph_mds_request *req)
 516 {
 517         if (req->r_session) {
 518                 ceph_put_mds_session(req->r_session);
 519                 req->r_session = NULL;
 520         }
 521 }
 522
 523 void ceph_mdsc_release_request(struct kref *kref)
 524 {
 525         struct ceph_mds_request *req = container_of(kref,
 526                                                     struct ceph_mds_request,
 527                                                     r_kref);
 528         destroy_reply_info(&req->r_reply_info);
 529         if (req->r_request)
 530                 ceph_msg_put(req->r_request);
 531         if (req->r_reply)
 532                 ceph_msg_put(req->r_reply);
 533         if (req->r_inode) {
 534                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 535                 iput(req->r_inode);
 536         }
 537         if (req->r_locked_dir)
 538                 ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
 539         iput(req->r_target_inode);
 540         if (req->r_dentry)
 541                 dput(req->r_dentry);
 542         if (req->r_old_dentry)
 543                 dput(req->r_old_dentry);
 544         if (req->r_old_dentry_dir) {
 545                 /*
 546                  * track (and drop pins for) r_old_dentry_dir
 547                  * separately, since r_old_dentry's d_parent may have
 548                  * changed between the dir mutex being dropped and
 549                  * this request being freed.
 550                  */
 551                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 552                                   CEPH_CAP_PIN);
 553                 iput(req->r_old_dentry_dir);
 554         }
 555         kfree(req->r_path1);
 556         kfree(req->r_path2);
 557         if (req->r_pagelist)
 558                 ceph_pagelist_release(req->r_pagelist);
 559         put_request_session(req);
 560         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 561         kfree(req);
 562 }
 563
 564 /*
 565  * lookup session, bump ref if found.
 566  *
 567  * called under mdsc->mutex.
 568  */
 569 static struct ceph_mds_request *__lookup_request(struct ceph_mds_client *mdsc,
 570                                              u64 tid)
 571 {
 572         struct ceph_mds_request *req;
 573         struct rb_node *n = mdsc->request_tree.rb_node;
 574
 575         while (n) {
 576                 req = rb_entry(n, struct ceph_mds_request, r_node);
 577                 if (tid < req->r_tid)
 578                         n = n->rb_left;
 579                 else if (tid > req->r_tid)
 580                         n = n->rb_right;
 581                 else {
 582                         ceph_mdsc_get_request(req);
 583                         return req;
 584                 }
 585         }
 586         return NULL;
 587 }
 588
 589 static void __insert_request(struct ceph_mds_client *mdsc,
 590                              struct ceph_mds_request *new)
 591 {
 592         struct rb_node **p = &mdsc->request_tree.rb_node;
 593         struct rb_node *parent = NULL;
 594         struct ceph_mds_request *req = NULL;
 595
 596         while (*p) {
 597                 parent = *p;
 598                 req = rb_entry(parent, struct ceph_mds_request, r_node);
 599                 if (new->r_tid < req->r_tid)
 600                         p = &(*p)->rb_left;
 601                 else if (new->r_tid > req->r_tid)
 602                         p = &(*p)->rb_right;
 603                 else
 604                         BUG();
 605         }
 606
 607         rb_link_node(&new->r_node, parent, p);
 608         rb_insert_color(&new->r_node, &mdsc->request_tree);
 609 }
 610
 611 /*
 612  * Register an in-flight request, and assign a tid.  Link to directory
 613  * are modifying (if any).
 614  *
 615  * Called under mdsc->mutex.
 616  */
 617 static void __register_request(struct ceph_mds_client *mdsc,
 618                                struct ceph_mds_request *req,
 619                                struct inode *dir)
 620 {
 621         req->r_tid = ++mdsc->last_tid;
 622         if (req->r_num_caps)
 623                 ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 624                                   req->r_num_caps);
 625         dout("__register_request %p tid %lld\n", req, req->r_tid);
 626         ceph_mdsc_get_request(req);
 627         __insert_request(mdsc, req);
 628
 629         req->r_uid = current_fsuid();
 630         req->r_gid = current_fsgid();
 631
 632         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 633                 mdsc->oldest_tid = req->r_tid;
 634
 635         if (dir) {
 636                 struct ceph_inode_info *ci = ceph_inode(dir);
 637
 638                 ihold(dir);
 639                 spin_lock(&ci->i_unsafe_lock);
 640                 req->r_unsafe_dir = dir;
 641                 list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 642                 spin_unlock(&ci->i_unsafe_lock);
 643         }
 644 }
 645
 646 static void __unregister_request(struct ceph_mds_client *mdsc,
 647                                  struct ceph_mds_request *req)
 648 {
 649         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 650
 651         if (req->r_tid == mdsc->oldest_tid) {
 652                 struct rb_node *p = rb_next(&req->r_node);
 653                 mdsc->oldest_tid = 0;
 654                 while (p) {
 655                         struct ceph_mds_request *next_req =
 656                                 rb_entry(p, struct ceph_mds_request, r_node);
 657                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 658                                 mdsc->oldest_tid = next_req->r_tid;
 659                                 break;
 660                         }
 661                         p = rb_next(p);
 662                 }
 663         }
 664
 665         rb_erase(&req->r_node, &mdsc->request_tree);
 666         RB_CLEAR_NODE(&req->r_node);
 667
 668         if (req->r_unsafe_dir) {
 669                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 670
 671                 spin_lock(&ci->i_unsafe_lock);
 672                 list_del_init(&req->r_unsafe_dir_item);
 673                 spin_unlock(&ci->i_unsafe_lock);
 674
 675                 iput(req->r_unsafe_dir);
 676                 req->r_unsafe_dir = NULL;
 677         }
 678
 679         complete_all(&req->r_safe_completion);
 680
 681         ceph_mdsc_put_request(req);
 682 }
 683
 684 /*
 685  * Choose mds to send request to next.  If there is a hint set in the
 686  * request (e.g., due to a prior forward hint from the mds), use that.
 687  * Otherwise, consult frag tree and/or caps to identify the
 688  * appropriate mds.  If all else fails, choose randomly.
 689  *
 690  * Called under mdsc->mutex.
 691  */
 692 static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 693 {
 694         /*
 695          * we don't need to worry about protecting the d_parent access
 696          * here because we never renaming inside the snapped namespace
 697          * except to resplice to another snapdir, and either the old or new
 698          * result is a valid result.
 699          */
 700         while (!IS_ROOT(dentry) && ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
 701                 dentry = dentry->d_parent;
 702         return dentry;
 703 }
 704
 705 static int __choose_mds(struct ceph_mds_client *mdsc,
 706                         struct ceph_mds_request *req)
 707 {
 708         struct inode *inode;
 709         struct ceph_inode_info *ci;
 710         struct ceph_cap *cap;
 711         int mode = req->r_direct_mode;
 712         int mds = -1;
 713         u32 hash = req->r_direct_hash;
 714         bool is_hash = req->r_direct_is_hash;
 715
 716         /*
 717          * is there a specific mds we should try?  ignore hint if we have
 718          * no session and the mds is not up (active or recovering).
 719          */
 720         if (req->r_resend_mds >= 0 &&
 721             (__have_session(mdsc, req->r_resend_mds) ||
 722              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 723                 dout("choose_mds using resend_mds mds%d\n",
 724                      req->r_resend_mds);
 725                 return req->r_resend_mds;
 726         }
 727
 728         if (mode == USE_RANDOM_MDS)
 729                 goto random;
 730
 731         inode = NULL;
 732         if (req->r_inode) {
 733                 inode = req->r_inode;
 734         } else if (req->r_dentry) {
 735                 /* ignore race with rename; old or new d_parent is okay */
 736                 struct dentry *parent = req->r_dentry->d_parent;
 737                 struct inode *dir = d_inode(parent);
 738
 739                 if (dir->i_sb != mdsc->fsc->sb) {
 740                         /* not this fs! */
 741                         inode = d_inode(req->r_dentry);
 742                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 743                         /* direct snapped/virtual snapdir requests
 744                          * based on parent dir inode */
 745                         struct dentry *dn = get_nonsnap_parent(parent);
 746                         inode = d_inode(dn);
 747                         dout("__choose_mds using nonsnap parent %p\n", inode);
 748                 } else {
 749                         /* dentry target */
 750                         inode = d_inode(req->r_dentry);
 751                         if (!inode || mode == USE_AUTH_MDS) {
 752                                 /* dir + name */
 753                                 inode = dir;
 754                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 755                                 is_hash = true;
 756                         }
 757                 }
 758         }
 759
 760         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 761              (int)hash, mode);
 762         if (!inode)
 763                 goto random;
 764         ci = ceph_inode(inode);
 765
 766         if (is_hash && S_ISDIR(inode->i_mode)) {
 767                 struct ceph_inode_frag frag;
 768                 int found;
 769
 770                 ceph_choose_frag(ci, hash, &frag, &found);
 771                 if (found) {
 772                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 773                                 u8 r;
 774
 775                                 /* choose a random replica */
 776                                 get_random_bytes(&r, 1);
 777                                 r %= frag.ndist;
 778                                 mds = frag.dist[r];
 779                                 dout("choose_mds %p %llx.%llx "
 780                                      "frag %u mds%d (%d/%d)\n",
 781                                      inode, ceph_vinop(inode),
 782                                      frag.frag, mds,
 783                                      (int)r, frag.ndist);
 784                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 785                                     CEPH_MDS_STATE_ACTIVE)
 786                                         return mds;
 787                         }
 788
 789                         /* since this file/dir wasn't known to be
 790                          * replicated, then we want to look for the
 791                          * authoritative mds. */
 792                         mode = USE_AUTH_MDS;
 793                         if (frag.mds >= 0) {
 794                                 /* choose auth mds */
 795                                 mds = frag.mds;
 796                                 dout("choose_mds %p %llx.%llx "
 797                                      "frag %u mds%d (auth)\n",
 798                                      inode, ceph_vinop(inode), frag.frag, mds);
 799                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 800                                     CEPH_MDS_STATE_ACTIVE)
 801                                         return mds;
 802                         }
 803                 }
 804         }
 805
 806         spin_lock(&ci->i_ceph_lock);
 807         cap = NULL;
 808         if (mode == USE_AUTH_MDS)
 809                 cap = ci->i_auth_cap;
 810         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 811                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 812         if (!cap) {
 813                 spin_unlock(&ci->i_ceph_lock);
 814                 goto random;
 815         }
 816         mds = cap->session->s_mds;
 817         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 818              inode, ceph_vinop(inode), mds,
 819              cap == ci->i_auth_cap ? "auth " : "", cap);
 820         spin_unlock(&ci->i_ceph_lock);
 821         return mds;
 822
 823 random:
 824         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 825         dout("choose_mds chose random mds%d\n", mds);
 826         return mds;
 827 }
 828
 829
 830 /*
 831  * session messages
 832  */
 833 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 834 {
 835         struct ceph_msg *msg;
 836         struct ceph_mds_session_head *h;
 837
 838         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 839                            false);
 840         if (!msg) {
 841                 pr_err("create_session_msg ENOMEM creating msg\n");
 842                 return NULL;
 843         }
 844         h = msg->front.iov_base;
 845         h->op = cpu_to_le32(op);
 846         h->seq = cpu_to_le64(seq);
 847
 848         return msg;
 849 }
 850
 851 /*
 852  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
 853  * to include additional client metadata fields.
 854  */
 855 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
 856 {
 857         struct ceph_msg *msg;
 858         struct ceph_mds_session_head *h;
 859         int i = -1;
 860         int metadata_bytes = 0;
 861         int metadata_key_count = 0;
 862         struct ceph_options *opt = mdsc->fsc->client->options;
 863         void *p;
 864
 865         const char* metadata[][2] = {
 866                 {"hostname", utsname()->nodename},
 867                 {"kernel_version", utsname()->release},
 868                 {"entity_id", opt->name ? opt->name : ""},
 869                 {NULL, NULL}
 870         };
 871
 872         /* Calculate serialized length of metadata */
 873         metadata_bytes = 4;  /* map length */
 874         for (i = 0; metadata[i][0] != NULL; ++i) {
 875                 metadata_bytes += 8 + strlen(metadata[i][0]) +
 876                         strlen(metadata[i][1]);
 877                 metadata_key_count++;
 878         }
 879
 880         /* Allocate the message */
 881         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + metadata_bytes,
 882                            GFP_NOFS, false);
 883         if (!msg) {
 884                 pr_err("create_session_msg ENOMEM creating msg\n");
 885                 return NULL;
 886         }
 887         h = msg->front.iov_base;
 888         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 889         h->seq = cpu_to_le64(seq);
 890
 891         /*
 892          * Serialize client metadata into waiting buffer space, using
 893          * the format that userspace expects for map<string, string>
 894          *
 895          * ClientSession messages with metadata are v2
 896          */
 897         msg->hdr.version = cpu_to_le16(2);
 898         msg->hdr.compat_version = cpu_to_le16(1);
 899
 900         /* The write pointer, following the session_head structure */
 901         p = msg->front.iov_base + sizeof(*h);
 902
 903         /* Number of entries in the map */
 904         ceph_encode_32(&p, metadata_key_count);
 905
 906         /* Two length-prefixed strings for each entry in the map */
 907         for (i = 0; metadata[i][0] != NULL; ++i) {
 908                 size_t const key_len = strlen(metadata[i][0]);
 909                 size_t const val_len = strlen(metadata[i][1]);
 910
 911                 ceph_encode_32(&p, key_len);
 912                 memcpy(p, metadata[i][0], key_len);
 913                 p += key_len;
 914                 ceph_encode_32(&p, val_len);
 915                 memcpy(p, metadata[i][1], val_len);
 916                 p += val_len;
 917         }
 918
 919         return msg;
 920 }
 921
 922 /*
 923  * send session open request.
 924  *
 925  * called under mdsc->mutex
 926  */
 927 static int __open_session(struct ceph_mds_client *mdsc,
 928                           struct ceph_mds_session *session)
 929 {
 930         struct ceph_msg *msg;
 931         int mstate;
 932         int mds = session->s_mds;
 933
 934         /* wait for mds to go active? */
 935         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 936         dout("open_session to mds%d (%s)\n", mds,
 937              ceph_mds_state_name(mstate));
 938         session->s_state = CEPH_MDS_SESSION_OPENING;
 939         session->s_renew_requested = jiffies;
 940
 941         /* send connect message */
 942         msg = create_session_open_msg(mdsc, session->s_seq);
 943         if (!msg)
 944                 return -ENOMEM;
 945         ceph_con_send(&session->s_con, msg);
 946         return 0;
 947 }
 948
 949 /*
 950  * open sessions for any export targets for the given mds
 951  *
 952  * called under mdsc->mutex
 953  */
 954 static struct ceph_mds_session *
 955 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
 956 {
 957         struct ceph_mds_session *session;
 958
 959         session = __ceph_lookup_mds_session(mdsc, target);
 960         if (!session) {
 961                 session = register_session(mdsc, target);
 962                 if (IS_ERR(session))
 963                         return session;
 964         }
 965         if (session->s_state == CEPH_MDS_SESSION_NEW ||
 966             session->s_state == CEPH_MDS_SESSION_CLOSING)
 967                 __open_session(mdsc, session);
 968
 969         return session;
 970 }
 971
 972 struct ceph_mds_session *
 973 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
 974 {
 975         struct ceph_mds_session *session;
 976
 977         dout("open_export_target_session to mds%d\n", target);
 978
 979         mutex_lock(&mdsc->mutex);
 980         session = __open_export_target_session(mdsc, target);
 981         mutex_unlock(&mdsc->mutex);
 982
 983         return session;
 984 }
 985
 986 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 987                                           struct ceph_mds_session *session)
 988 {
 989         struct ceph_mds_info *mi;
 990         struct ceph_mds_session *ts;
 991         int i, mds = session->s_mds;
 992
 993         if (mds >= mdsc->mdsmap->m_max_mds)
 994                 return;
 995
 996         mi = &mdsc->mdsmap->m_info[mds];
 997         dout("open_export_target_sessions for mds%d (%d targets)\n",
 998              session->s_mds, mi->num_export_targets);
 999
1000         for (i = 0; i < mi->num_export_targets; i++) {
1001                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1002                 if (!IS_ERR(ts))
1003                         ceph_put_mds_session(ts);
1004         }
1005 }
1006
1007 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1008                                            struct ceph_mds_session *session)
1009 {
1010         mutex_lock(&mdsc->mutex);
1011         __open_export_target_sessions(mdsc, session);
1012         mutex_unlock(&mdsc->mutex);
1013 }
1014
1015 /*
1016  * session caps
1017  */
1018
1019 /* caller holds s_cap_lock, we drop it */
1020 static void cleanup_cap_releases(struct ceph_mds_client *mdsc,
1021                                  struct ceph_mds_session *session)
1022         __releases(session->s_cap_lock)
1023 {
1024         LIST_HEAD(tmp_list);
1025         list_splice_init(&session->s_cap_releases, &tmp_list);
1026         session->s_num_cap_releases = 0;
1027         spin_unlock(&session->s_cap_lock);
1028
1029         dout("cleanup_cap_releases mds%d\n", session->s_mds);
1030         while (!list_empty(&tmp_list)) {
1031                 struct ceph_cap *cap;
1032                 /* zero out the in-progress message */
1033                 cap = list_first_entry(&tmp_list,
1034                                         struct ceph_cap, session_caps);
1035                 list_del(&cap->session_caps);
1036                 ceph_put_cap(mdsc, cap);
1037         }
1038 }
1039
1040 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1041                                      struct ceph_mds_session *session)
1042 {
1043         struct ceph_mds_request *req;
1044         struct rb_node *p;
1045
1046         dout("cleanup_session_requests mds%d\n", session->s_mds);
1047         mutex_lock(&mdsc->mutex);
1048         while (!list_empty(&session->s_unsafe)) {
1049                 req = list_first_entry(&session->s_unsafe,
1050                                        struct ceph_mds_request, r_unsafe_item);
1051                 list_del_init(&req->r_unsafe_item);
1052                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1053                                     req->r_tid);
1054                 __unregister_request(mdsc, req);
1055         }
1056         /* zero r_attempts, so kick_requests() will re-send requests */
1057         p = rb_first(&mdsc->request_tree);
1058         while (p) {
1059                 req = rb_entry(p, struct ceph_mds_request, r_node);
1060                 p = rb_next(p);
1061                 if (req->r_session &&
1062                     req->r_session->s_mds == session->s_mds)
1063                         req->r_attempts = 0;
1064         }
1065         mutex_unlock(&mdsc->mutex);
1066 }
1067
1068 /*
1069  * Helper to safely iterate over all caps associated with a session, with
1070  * special care taken to handle a racing __ceph_remove_cap().
1071  *
1072  * Caller must hold session s_mutex.
1073  */
1074 static int iterate_session_caps(struct ceph_mds_session *session,
1075                                  int (*cb)(struct inode *, struct ceph_cap *,
1076                                             void *), void *arg)
1077 {
1078         struct list_head *p;
1079         struct ceph_cap *cap;
1080         struct inode *inode, *last_inode = NULL;
1081         struct ceph_cap *old_cap = NULL;
1082         int ret;
1083
1084         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1085         spin_lock(&session->s_cap_lock);
1086         p = session->s_caps.next;
1087         while (p != &session->s_caps) {
1088                 cap = list_entry(p, struct ceph_cap, session_caps);
1089                 inode = igrab(&cap->ci->vfs_inode);
1090                 if (!inode) {
1091                         p = p->next;
1092                         continue;
1093                 }
1094                 session->s_cap_iterator = cap;
1095                 spin_unlock(&session->s_cap_lock);
1096
1097                 if (last_inode) {
1098                         iput(last_inode);
1099                         last_inode = NULL;
1100                 }
1101                 if (old_cap) {
1102                         ceph_put_cap(session->s_mdsc, old_cap);
1103                         old_cap = NULL;
1104                 }
1105
1106                 ret = cb(inode, cap, arg);
1107                 last_inode = inode;
1108
1109                 spin_lock(&session->s_cap_lock);
1110                 p = p->next;
1111                 if (cap->ci == NULL) {
1112                         dout("iterate_session_caps  finishing cap %p removal\n",
1113                              cap);
1114                         BUG_ON(cap->session != session);
1115                         cap->session = NULL;
1116                         list_del_init(&cap->session_caps);
1117                         session->s_nr_caps--;
1118                         if (cap->queue_release) {
1119                                 list_add_tail(&cap->session_caps,
1120                                               &session->s_cap_releases);
1121                                 session->s_num_cap_releases++;
1122                         } else {
1123                                 old_cap = cap;  /* put_cap it w/o locks held */
1124                         }
1125                 }
1126                 if (ret < 0)
1127                         goto out;
1128         }
1129         ret = 0;
1130 out:
1131         session->s_cap_iterator = NULL;
1132         spin_unlock(&session->s_cap_lock);
1133
1134         iput(last_inode);
1135         if (old_cap)
1136                 ceph_put_cap(session->s_mdsc, old_cap);
1137
1138         return ret;
1139 }
1140
1141 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1142                                   void *arg)
1143 {
1144         struct ceph_inode_info *ci = ceph_inode(inode);
1145         LIST_HEAD(to_remove);
1146         int drop = 0;
1147
1148         dout("removing cap %p, ci is %p, inode is %p\n",
1149              cap, ci, &ci->vfs_inode);
1150         spin_lock(&ci->i_ceph_lock);
1151         __ceph_remove_cap(cap, false);
1152         if (!ci->i_auth_cap) {
1153                 struct ceph_cap_flush *cf;
1154                 struct ceph_mds_client *mdsc =
1155                         ceph_sb_to_client(inode->i_sb)->mdsc;
1156
1157                 while (true) {
1158                         struct rb_node *n = rb_first(&ci->i_cap_flush_tree);
1159                         if (!n)
1160                                 break;
1161                         cf = rb_entry(n, struct ceph_cap_flush, i_node);
1162                         rb_erase(&cf->i_node, &ci->i_cap_flush_tree);
1163                         list_add(&cf->list, &to_remove);
1164                 }
1165
1166                 spin_lock(&mdsc->cap_dirty_lock);
1167                 if (!list_empty(&ci->i_dirty_item)) {
1168                         pr_warn_ratelimited(
1169                                 " dropping dirty %s state for %p %lld\n",
1170                                 ceph_cap_string(ci->i_dirty_caps),
1171                                 inode, ceph_ino(inode));
1172                         ci->i_dirty_caps = 0;
1173                         list_del_init(&ci->i_dirty_item);
1174                         drop = 1;
1175                 }
1176                 if (!list_empty(&ci->i_flushing_item)) {
1177                         pr_warn_ratelimited(
1178                                 " dropping dirty+flushing %s state for %p %lld\n",
1179                                 ceph_cap_string(ci->i_flushing_caps),
1180                                 inode, ceph_ino(inode));
1181                         ci->i_flushing_caps = 0;
1182                         list_del_init(&ci->i_flushing_item);
1183                         mdsc->num_cap_flushing--;
1184                         drop = 1;
1185                 }
1186                 spin_unlock(&mdsc->cap_dirty_lock);
1187
1188         }
1189         spin_unlock(&ci->i_ceph_lock);
1190         while (!list_empty(&to_remove)) {
1191                 struct ceph_cap_flush *cf;
1192                 cf = list_first_entry(&to_remove,
1193                                       struct ceph_cap_flush, list);
1194                 list_del(&cf->list);
1195                 kfree(cf);
1196         }
1197         while (drop--)
1198                 iput(inode);
1199         return 0;
1200 }
1201
1202 /*
1203  * caller must hold session s_mutex
1204  */
1205 static void remove_session_caps(struct ceph_mds_session *session)
1206 {
1207         dout("remove_session_caps on %p\n", session);
1208         iterate_session_caps(session, remove_session_caps_cb, NULL);
1209
1210         spin_lock(&session->s_cap_lock);
1211         if (session->s_nr_caps > 0) {
1212                 struct super_block *sb = session->s_mdsc->fsc->sb;
1213                 struct inode *inode;
1214                 struct ceph_cap *cap, *prev = NULL;
1215                 struct ceph_vino vino;
1216                 /*
1217                  * iterate_session_caps() skips inodes that are being
1218                  * deleted, we need to wait until deletions are complete.
1219                  * __wait_on_freeing_inode() is designed for the job,
1220                  * but it is not exported, so use lookup inode function
1221                  * to access it.
1222                  */
1223                 while (!list_empty(&session->s_caps)) {
1224                         cap = list_entry(session->s_caps.next,
1225                                          struct ceph_cap, session_caps);
1226                         if (cap == prev)
1227                                 break;
1228                         prev = cap;
1229                         vino = cap->ci->i_vino;
1230                         spin_unlock(&session->s_cap_lock);
1231
1232                         inode = ceph_find_inode(sb, vino);
1233                         iput(inode);
1234
1235                         spin_lock(&session->s_cap_lock);
1236                 }
1237         }
1238
1239         // drop cap expires and unlock s_cap_lock
1240         cleanup_cap_releases(session->s_mdsc, session);
1241
1242         BUG_ON(session->s_nr_caps > 0);
1243         BUG_ON(!list_empty(&session->s_cap_flushing));
1244 }
1245
1246 /*
1247  * wake up any threads waiting on this session's caps.  if the cap is
1248  * old (didn't get renewed on the client reconnect), remove it now.
1249  *
1250  * caller must hold s_mutex.
1251  */
1252 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1253                               void *arg)
1254 {
1255         struct ceph_inode_info *ci = ceph_inode(inode);
1256
1257         wake_up_all(&ci->i_cap_wq);
1258         if (arg) {
1259                 spin_lock(&ci->i_ceph_lock);
1260                 ci->i_wanted_max_size = 0;
1261                 ci->i_requested_max_size = 0;
1262                 spin_unlock(&ci->i_ceph_lock);
1263         }
1264         return 0;
1265 }
1266
1267 static void wake_up_session_caps(struct ceph_mds_session *session,
1268                                  int reconnect)
1269 {
1270         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1271         iterate_session_caps(session, wake_up_session_cb,
1272                              (void *)(unsigned long)reconnect);
1273 }
1274
1275 /*
1276  * Send periodic message to MDS renewing all currently held caps.  The
1277  * ack will reset the expiration for all caps from this session.
1278  *
1279  * caller holds s_mutex
1280  */
1281 static int send_renew_caps(struct ceph_mds_client *mdsc,
1282                            struct ceph_mds_session *session)
1283 {
1284         struct ceph_msg *msg;
1285         int state;
1286
1287         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1288             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1289                 pr_info("mds%d caps stale\n", session->s_mds);
1290         session->s_renew_requested = jiffies;
1291
1292         /* do not try to renew caps until a recovering mds has reconnected
1293          * with its clients. */
1294         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1295         if (state < CEPH_MDS_STATE_RECONNECT) {
1296                 dout("send_renew_caps ignoring mds%d (%s)\n",
1297                      session->s_mds, ceph_mds_state_name(state));
1298                 return 0;
1299         }
1300
1301         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1302                 ceph_mds_state_name(state));
1303         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1304                                  ++session->s_renew_seq);
1305         if (!msg)
1306                 return -ENOMEM;
1307         ceph_con_send(&session->s_con, msg);
1308         return 0;
1309 }
1310
1311 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1312                              struct ceph_mds_session *session, u64 seq)
1313 {
1314         struct ceph_msg *msg;
1315
1316         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1317              session->s_mds, ceph_session_state_name(session->s_state), seq);
1318         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1319         if (!msg)
1320                 return -ENOMEM;
1321         ceph_con_send(&session->s_con, msg);
1322         return 0;
1323 }
1324
1325
1326 /*
1327  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1328  *
1329  * Called under session->s_mutex
1330  */
1331 static void renewed_caps(struct ceph_mds_client *mdsc,
1332                          struct ceph_mds_session *session, int is_renew)
1333 {
1334         int was_stale;
1335         int wake = 0;
1336
1337         spin_lock(&session->s_cap_lock);
1338         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1339
1340         session->s_cap_ttl = session->s_renew_requested +
1341                 mdsc->mdsmap->m_session_timeout*HZ;
1342
1343         if (was_stale) {
1344                 if (time_before(jiffies, session->s_cap_ttl)) {
1345                         pr_info("mds%d caps renewed\n", session->s_mds);
1346                         wake = 1;
1347                 } else {
1348                         pr_info("mds%d caps still stale\n", session->s_mds);
1349                 }
1350         }
1351         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1352              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1353              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1354         spin_unlock(&session->s_cap_lock);
1355
1356         if (wake)
1357                 wake_up_session_caps(session, 0);
1358 }
1359
1360 /*
1361  * send a session close request
1362  */
1363 static int request_close_session(struct ceph_mds_client *mdsc,
1364                                  struct ceph_mds_session *session)
1365 {
1366         struct ceph_msg *msg;
1367
1368         dout("request_close_session mds%d state %s seq %lld\n",
1369              session->s_mds, ceph_session_state_name(session->s_state),
1370              session->s_seq);
1371         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1372         if (!msg)
1373                 return -ENOMEM;
1374         ceph_con_send(&session->s_con, msg);
1375         return 0;
1376 }
1377
1378 /*
1379  * Called with s_mutex held.
1380  */
1381 static int __close_session(struct ceph_mds_client *mdsc,
1382                          struct ceph_mds_session *session)
1383 {
1384         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1385                 return 0;
1386         session->s_state = CEPH_MDS_SESSION_CLOSING;
1387         return request_close_session(mdsc, session);
1388 }
1389
1390 /*
1391  * Trim old(er) caps.
1392  *
1393  * Because we can't cache an inode without one or more caps, we do
1394  * this indirectly: if a cap is unused, we prune its aliases, at which
1395  * point the inode will hopefully get dropped to.
1396  *
1397  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1398  * memory pressure from the MDS, though, so it needn't be perfect.
1399  */
1400 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1401 {
1402         struct ceph_mds_session *session = arg;
1403         struct ceph_inode_info *ci = ceph_inode(inode);
1404         int used, wanted, oissued, mine;
1405
1406         if (session->s_trim_caps <= 0)
1407                 return -1;
1408
1409         spin_lock(&ci->i_ceph_lock);
1410         mine = cap->issued | cap->implemented;
1411         used = __ceph_caps_used(ci);
1412         wanted = __ceph_caps_file_wanted(ci);
1413         oissued = __ceph_caps_issued_other(ci, cap);
1414
1415         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1416              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1417              ceph_cap_string(used), ceph_cap_string(wanted));
1418         if (cap == ci->i_auth_cap) {
1419                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1420                     !list_empty(&ci->i_cap_snaps))
1421                         goto out;
1422                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1423                         goto out;
1424         }
1425         if ((used | wanted) & ~oissued & mine)
1426                 goto out;   /* we need these caps */
1427
1428         session->s_trim_caps--;
1429         if (oissued) {
1430                 /* we aren't the only cap.. just remove us */
1431                 __ceph_remove_cap(cap, true);
1432         } else {
1433                 /* try to drop referring dentries */
1434                 spin_unlock(&ci->i_ceph_lock);
1435                 d_prune_aliases(inode);
1436                 dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1437                      inode, cap, atomic_read(&inode->i_count));
1438                 return 0;
1439         }
1440
1441 out:
1442         spin_unlock(&ci->i_ceph_lock);
1443         return 0;
1444 }
1445
1446 /*
1447  * Trim session cap count down to some max number.
1448  */
1449 static int trim_caps(struct ceph_mds_client *mdsc,
1450                      struct ceph_mds_session *session,
1451                      int max_caps)
1452 {
1453         int trim_caps = session->s_nr_caps - max_caps;
1454
1455         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1456              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1457         if (trim_caps > 0) {
1458                 session->s_trim_caps = trim_caps;
1459                 iterate_session_caps(session, trim_caps_cb, session);
1460                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1461                      session->s_mds, session->s_nr_caps, max_caps,
1462                         trim_caps - session->s_trim_caps);
1463                 session->s_trim_caps = 0;
1464         }
1465
1466         ceph_send_cap_releases(mdsc, session);
1467         return 0;
1468 }
1469
1470 static int check_cap_flush(struct ceph_inode_info *ci,
1471                            u64 want_flush_seq, u64 want_snap_seq)
1472 {
1473         int ret1 = 1, ret2 = 1;
1474         spin_lock(&ci->i_ceph_lock);
1475         if (want_flush_seq > 0 && ci->i_flushing_caps)
1476                 ret1 = ci->i_cap_flush_seq >= want_flush_seq;
1477
1478         if (want_snap_seq > 0 && !list_empty(&ci->i_cap_snaps)) {
1479                 struct ceph_cap_snap *capsnap =
1480                         list_first_entry(&ci->i_cap_snaps,
1481                                          struct ceph_cap_snap, ci_item);
1482                 ret2 = capsnap->follows >= want_snap_seq;
1483         }
1484         spin_unlock(&ci->i_ceph_lock);
1485         return ret1 && ret2;
1486 }
1487
1488 /*
1489  * flush all dirty inode data to disk.
1490  *
1491  * returns true if we've flushed through want_flush_seq
1492  */
1493 static void wait_caps_flush(struct ceph_mds_client *mdsc,
1494                             u64 want_flush_seq, u64 want_snap_seq)
1495 {
1496         int mds;
1497
1498         dout("check_cap_flush want %lld\n", want_flush_seq);
1499         mutex_lock(&mdsc->mutex);
1500         for (mds = 0; mds < mdsc->max_sessions; ) {
1501                 struct ceph_mds_session *session = mdsc->sessions[mds];
1502                 struct inode *inode1 = NULL, *inode2 = NULL;
1503
1504                 if (!session) {
1505                         mds++;
1506                         continue;
1507                 }
1508                 get_session(session);
1509                 mutex_unlock(&mdsc->mutex);
1510
1511                 mutex_lock(&session->s_mutex);
1512                 if (!list_empty(&session->s_cap_flushing)) {
1513                         struct ceph_inode_info *ci =
1514                                 list_first_entry(&session->s_cap_flushing,
1515                                                  struct ceph_inode_info,
1516                                                  i_flushing_item);
1517
1518                         if (!check_cap_flush(ci, want_flush_seq, 0)) {
1519                                 dout("check_cap_flush still flushing %p "
1520                                      "seq %lld <= %lld to mds%d\n",
1521                                      &ci->vfs_inode, ci->i_cap_flush_seq,
1522                                      want_flush_seq, mds);
1523                                 inode1 = igrab(&ci->vfs_inode);
1524                         }
1525                 }
1526                 if (!list_empty(&session->s_cap_snaps_flushing)) {
1527                         struct ceph_cap_snap *capsnap =
1528                                 list_first_entry(&session->s_cap_snaps_flushing,
1529                                                  struct ceph_cap_snap,
1530                                                  flushing_item);
1531                         struct ceph_inode_info *ci = capsnap->ci;
1532                         if (!check_cap_flush(ci, 0, want_snap_seq)) {
1533                                 dout("check_cap_flush still flushing snap %p "
1534                                      "follows %lld <= %lld to mds%d\n",
1535                                      &ci->vfs_inode, capsnap->follows,
1536                                      want_snap_seq, mds);
1537                                 inode2 = igrab(&ci->vfs_inode);
1538                         }
1539                 }
1540                 mutex_unlock(&session->s_mutex);
1541                 ceph_put_mds_session(session);
1542
1543                 if (inode1) {
1544                         wait_event(mdsc->cap_flushing_wq,
1545                                    check_cap_flush(ceph_inode(inode1),
1546                                                    want_flush_seq, 0));
1547                         iput(inode1);
1548                 }
1549                 if (inode2) {
1550                         wait_event(mdsc->cap_flushing_wq,
1551                                    check_cap_flush(ceph_inode(inode2),
1552                                                    0, want_snap_seq));
1553                         iput(inode2);
1554                 }
1555
1556                 if (!inode1 && !inode2)
1557                         mds++;
1558
1559                 mutex_lock(&mdsc->mutex);
1560         }
1561
1562         mutex_unlock(&mdsc->mutex);
1563         dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq);
1564 }
1565
1566 /*
1567  * called under s_mutex
1568  */
1569 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1570                             struct ceph_mds_session *session)
1571 {
1572         struct ceph_msg *msg = NULL;
1573         struct ceph_mds_cap_release *head;
1574         struct ceph_mds_cap_item *item;
1575         struct ceph_cap *cap;
1576         LIST_HEAD(tmp_list);
1577         int num_cap_releases;
1578
1579         spin_lock(&session->s_cap_lock);
1580 again:
1581         list_splice_init(&session->s_cap_releases, &tmp_list);
1582         num_cap_releases = session->s_num_cap_releases;
1583         session->s_num_cap_releases = 0;
1584         spin_unlock(&session->s_cap_lock);
1585
1586         while (!list_empty(&tmp_list)) {
1587                 if (!msg) {
1588                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1589                                         PAGE_CACHE_SIZE, GFP_NOFS, false);
1590                         if (!msg)
1591                                 goto out_err;
1592                         head = msg->front.iov_base;
1593                         head->num = cpu_to_le32(0);
1594                         msg->front.iov_len = sizeof(*head);
1595                 }
1596                 cap = list_first_entry(&tmp_list, struct ceph_cap,
1597                                         session_caps);
1598                 list_del(&cap->session_caps);
1599                 num_cap_releases--;
1600
1601                 head = msg->front.iov_base;
1602                 le32_add_cpu(&head->num, 1);
1603                 item = msg->front.iov_base + msg->front.iov_len;
1604                 item->ino = cpu_to_le64(cap->cap_ino);
1605                 item->cap_id = cpu_to_le64(cap->cap_id);
1606                 item->migrate_seq = cpu_to_le32(cap->mseq);
1607                 item->seq = cpu_to_le32(cap->issue_seq);
1608                 msg->front.iov_len += sizeof(*item);
1609
1610                 ceph_put_cap(mdsc, cap);
1611
1612                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1613                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1614                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1615                         ceph_con_send(&session->s_con, msg);
1616                         msg = NULL;
1617                 }
1618         }
1619
1620         BUG_ON(num_cap_releases != 0);
1621
1622         spin_lock(&session->s_cap_lock);
1623         if (!list_empty(&session->s_cap_releases))
1624                 goto again;
1625         spin_unlock(&session->s_cap_lock);
1626
1627         if (msg) {
1628                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1629                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1630                 ceph_con_send(&session->s_con, msg);
1631         }
1632         return;
1633 out_err:
1634         pr_err("send_cap_releases mds%d, failed to allocate message\n",
1635                 session->s_mds);
1636         spin_lock(&session->s_cap_lock);
1637         list_splice(&tmp_list, &session->s_cap_releases);
1638         session->s_num_cap_releases += num_cap_releases;
1639         spin_unlock(&session->s_cap_lock);
1640 }
1641
1642 /*
1643  * requests
1644  */
1645
1646 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1647                                     struct inode *dir)
1648 {
1649         struct ceph_inode_info *ci = ceph_inode(dir);
1650         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1651         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1652         size_t size = sizeof(*rinfo->dir_in) + sizeof(*rinfo->dir_dname_len) +
1653                       sizeof(*rinfo->dir_dname) + sizeof(*rinfo->dir_dlease);
1654         int order, num_entries;
1655
1656         spin_lock(&ci->i_ceph_lock);
1657         num_entries = ci->i_files + ci->i_subdirs;
1658         spin_unlock(&ci->i_ceph_lock);
1659         num_entries = max(num_entries, 1);
1660         num_entries = min(num_entries, opt->max_readdir);
1661
1662         order = get_order(size * num_entries);
1663         while (order >= 0) {
1664                 rinfo->dir_in = (void*)__get_free_pages(GFP_NOFS | __GFP_NOWARN,
1665                                                         order);
1666                 if (rinfo->dir_in)
1667                         break;
1668                 order--;
1669         }
1670         if (!rinfo->dir_in)
1671                 return -ENOMEM;
1672
1673         num_entries = (PAGE_SIZE << order) / size;
1674         num_entries = min(num_entries, opt->max_readdir);
1675
1676         rinfo->dir_buf_size = PAGE_SIZE << order;
1677         req->r_num_caps = num_entries + 1;
1678         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1679         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1680         return 0;
1681 }
1682
1683 /*
1684  * Create an mds request.
1685  */
1686 struct ceph_mds_request *
1687 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1688 {
1689         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1690
1691         if (!req)
1692                 return ERR_PTR(-ENOMEM);
1693
1694         mutex_init(&req->r_fill_mutex);
1695         req->r_mdsc = mdsc;
1696         req->r_started = jiffies;
1697         req->r_resend_mds = -1;
1698         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1699         req->r_fmode = -1;
1700         kref_init(&req->r_kref);
1701         INIT_LIST_HEAD(&req->r_wait);
1702         init_completion(&req->r_completion);
1703         init_completion(&req->r_safe_completion);
1704         INIT_LIST_HEAD(&req->r_unsafe_item);
1705
1706         req->r_stamp = CURRENT_TIME;
1707
1708         req->r_op = op;
1709         req->r_direct_mode = mode;
1710         return req;
1711 }
1712
1713 /*
1714  * return oldest (lowest) request, tid in request tree, 0 if none.
1715  *
1716  * called under mdsc->mutex.
1717  */
1718 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1719 {
1720         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1721                 return NULL;
1722         return rb_entry(rb_first(&mdsc->request_tree),
1723                         struct ceph_mds_request, r_node);
1724 }
1725
1726 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1727 {
1728         return mdsc->oldest_tid;
1729 }
1730
1731 /*
1732  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1733  * on build_path_from_dentry in fs/cifs/dir.c.
1734  *
1735  * If @stop_on_nosnap, generate path relative to the first non-snapped
1736  * inode.
1737  *
1738  * Encode hidden .snap dirs as a double /, i.e.
1739  *   foo/.snap/bar -> foo//bar
1740  */
1741 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1742                            int stop_on_nosnap)
1743 {
1744         struct dentry *temp;
1745         char *path;
1746         int len, pos;
1747         unsigned seq;
1748
1749         if (dentry == NULL)
1750                 return ERR_PTR(-EINVAL);
1751
1752 retry:
1753         len = 0;
1754         seq = read_seqbegin(&rename_lock);
1755         rcu_read_lock();
1756         for (temp = dentry; !IS_ROOT(temp);) {
1757                 struct inode *inode = d_inode(temp);
1758                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1759                         len++;  /* slash only */
1760                 else if (stop_on_nosnap && inode &&
1761                          ceph_snap(inode) == CEPH_NOSNAP)
1762                         break;
1763                 else
1764                         len += 1 + temp->d_name.len;
1765                 temp = temp->d_parent;
1766         }
1767         rcu_read_unlock();
1768         if (len)
1769                 len--;  /* no leading '/' */
1770
1771         path = kmalloc(len+1, GFP_NOFS);
1772         if (path == NULL)
1773                 return ERR_PTR(-ENOMEM);
1774         pos = len;
1775         path[pos] = 0;  /* trailing null */
1776         rcu_read_lock();
1777         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1778                 struct inode *inode;
1779
1780                 spin_lock(&temp->d_lock);
1781                 inode = d_inode(temp);
1782                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1783                         dout("build_path path+%d: %p SNAPDIR\n",
1784                              pos, temp);
1785                 } else if (stop_on_nosnap && inode &&
1786                            ceph_snap(inode) == CEPH_NOSNAP) {
1787                         spin_unlock(&temp->d_lock);
1788                         break;
1789                 } else {
1790                         pos -= temp->d_name.len;
1791                         if (pos < 0) {
1792                                 spin_unlock(&temp->d_lock);
1793                                 break;
1794                         }
1795                         strncpy(path + pos, temp->d_name.name,
1796                                 temp->d_name.len);
1797                 }
1798                 spin_unlock(&temp->d_lock);
1799                 if (pos)
1800                         path[--pos] = '/';
1801                 temp = temp->d_parent;
1802         }
1803         rcu_read_unlock();
1804         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1805                 pr_err("build_path did not end path lookup where "
1806                        "expected, namelen is %d, pos is %d\n", len, pos);
1807                 /* presumably this is only possible if racing with a
1808                    rename of one of the parent directories (we can not
1809                    lock the dentries above us to prevent this, but
1810                    retrying should be harmless) */
1811                 kfree(path);
1812                 goto retry;
1813         }
1814
1815         *base = ceph_ino(d_inode(temp));
1816         *plen = len;
1817         dout("build_path on %p %d built %llx '%.*s'\n",
1818              dentry, d_count(dentry), *base, len, path);
1819         return path;
1820 }
1821
1822 static int build_dentry_path(struct dentry *dentry,
1823                              const char **ppath, int *ppathlen, u64 *pino,
1824                              int *pfreepath)
1825 {
1826         char *path;
1827
1828         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP) {
1829                 *pino = ceph_ino(d_inode(dentry->d_parent));
1830                 *ppath = dentry->d_name.name;
1831                 *ppathlen = dentry->d_name.len;
1832                 return 0;
1833         }
1834         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1835         if (IS_ERR(path))
1836                 return PTR_ERR(path);
1837         *ppath = path;
1838         *pfreepath = 1;
1839         return 0;
1840 }
1841
1842 static int build_inode_path(struct inode *inode,
1843                             const char **ppath, int *ppathlen, u64 *pino,
1844                             int *pfreepath)
1845 {
1846         struct dentry *dentry;
1847         char *path;
1848
1849         if (ceph_snap(inode) == CEPH_NOSNAP) {
1850                 *pino = ceph_ino(inode);
1851                 *ppathlen = 0;
1852                 return 0;
1853         }
1854         dentry = d_find_alias(inode);
1855         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1856         dput(dentry);
1857         if (IS_ERR(path))
1858                 return PTR_ERR(path);
1859         *ppath = path;
1860         *pfreepath = 1;
1861         return 0;
1862 }
1863
1864 /*
1865  * request arguments may be specified via an inode *, a dentry *, or
1866  * an explicit ino+path.
1867  */
1868 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1869                                   const char *rpath, u64 rino,
1870                                   const char **ppath, int *pathlen,
1871                                   u64 *ino, int *freepath)
1872 {
1873         int r = 0;
1874
1875         if (rinode) {
1876                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1877                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1878                      ceph_snap(rinode));
1879         } else if (rdentry) {
1880                 r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1881                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1882                      *ppath);
1883         } else if (rpath || rino) {
1884                 *ino = rino;
1885                 *ppath = rpath;
1886                 *pathlen = rpath ? strlen(rpath) : 0;
1887                 dout(" path %.*s\n", *pathlen, rpath);
1888         }
1889
1890         return r;
1891 }
1892
1893 /*
1894  * called under mdsc->mutex
1895  */
1896 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1897                                                struct ceph_mds_request *req,
1898                                                int mds, bool drop_cap_releases)
1899 {
1900         struct ceph_msg *msg;
1901         struct ceph_mds_request_head *head;
1902         const char *path1 = NULL;
1903         const char *path2 = NULL;
1904         u64 ino1 = 0, ino2 = 0;
1905         int pathlen1 = 0, pathlen2 = 0;
1906         int freepath1 = 0, freepath2 = 0;
1907         int len;
1908         u16 releases;
1909         void *p, *end;
1910         int ret;
1911
1912         ret = set_request_path_attr(req->r_inode, req->r_dentry,
1913                               req->r_path1, req->r_ino1.ino,
1914                               &path1, &pathlen1, &ino1, &freepath1);
1915         if (ret < 0) {
1916                 msg = ERR_PTR(ret);
1917                 goto out;
1918         }
1919
1920         ret = set_request_path_attr(NULL, req->r_old_dentry,
1921                               req->r_path2, req->r_ino2.ino,
1922                               &path2, &pathlen2, &ino2, &freepath2);
1923         if (ret < 0) {
1924                 msg = ERR_PTR(ret);
1925                 goto out_free1;
1926         }
1927
1928         len = sizeof(*head) +
1929                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1930                 sizeof(struct timespec);
1931
1932         /* calculate (max) length for cap releases */
1933         len += sizeof(struct ceph_mds_request_release) *
1934                 (!!req->r_inode_drop + !!req->r_dentry_drop +
1935                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1936         if (req->r_dentry_drop)
1937                 len += req->r_dentry->d_name.len;
1938         if (req->r_old_dentry_drop)
1939                 len += req->r_old_dentry->d_name.len;
1940
1941         msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1942         if (!msg) {
1943                 msg = ERR_PTR(-ENOMEM);
1944                 goto out_free2;
1945         }
1946
1947         msg->hdr.version = cpu_to_le16(2);
1948         msg->hdr.tid = cpu_to_le64(req->r_tid);
1949
1950         head = msg->front.iov_base;
1951         p = msg->front.iov_base + sizeof(*head);
1952         end = msg->front.iov_base + msg->front.iov_len;
1953
1954         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1955         head->op = cpu_to_le32(req->r_op);
1956         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1957         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1958         head->args = req->r_args;
1959
1960         ceph_encode_filepath(&p, end, ino1, path1);
1961         ceph_encode_filepath(&p, end, ino2, path2);
1962
1963         /* make note of release offset, in case we need to replay */
1964         req->r_request_release_offset = p - msg->front.iov_base;
1965
1966         /* cap releases */
1967         releases = 0;
1968         if (req->r_inode_drop)
1969                 releases += ceph_encode_inode_release(&p,
1970                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
1971                       mds, req->r_inode_drop, req->r_inode_unless, 0);
1972         if (req->r_dentry_drop)
1973                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
1974                        mds, req->r_dentry_drop, req->r_dentry_unless);
1975         if (req->r_old_dentry_drop)
1976                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1977                        mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1978         if (req->r_old_inode_drop)
1979                 releases += ceph_encode_inode_release(&p,
1980                       d_inode(req->r_old_dentry),
1981                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1982
1983         if (drop_cap_releases) {
1984                 releases = 0;
1985                 p = msg->front.iov_base + req->r_request_release_offset;
1986         }
1987
1988         head->num_releases = cpu_to_le16(releases);
1989
1990         /* time stamp */
1991         {
1992                 struct ceph_timespec ts;
1993                 ceph_encode_timespec(&ts, &req->r_stamp);
1994                 ceph_encode_copy(&p, &ts, sizeof(ts));
1995         }
1996
1997         BUG_ON(p > end);
1998         msg->front.iov_len = p - msg->front.iov_base;
1999         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2000
2001         if (req->r_pagelist) {
2002                 struct ceph_pagelist *pagelist = req->r_pagelist;
2003                 atomic_inc(&pagelist->refcnt);
2004                 ceph_msg_data_add_pagelist(msg, pagelist);
2005                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2006         } else {
2007                 msg->hdr.data_len = 0;
2008         }
2009
2010         msg->hdr.data_off = cpu_to_le16(0);
2011
2012 out_free2:
2013         if (freepath2)
2014                 kfree((char *)path2);
2015 out_free1:
2016         if (freepath1)
2017                 kfree((char *)path1);
2018 out:
2019         return msg;
2020 }
2021
2022 /*
2023  * called under mdsc->mutex if error, under no mutex if
2024  * success.
2025  */
2026 static void complete_request(struct ceph_mds_client *mdsc,
2027                              struct ceph_mds_request *req)
2028 {
2029         if (req->r_callback)
2030                 req->r_callback(mdsc, req);
2031         else
2032                 complete_all(&req->r_completion);
2033 }
2034
2035 /*
2036  * called under mdsc->mutex
2037  */
2038 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2039                                   struct ceph_mds_request *req,
2040                                   int mds, bool drop_cap_releases)
2041 {
2042         struct ceph_mds_request_head *rhead;
2043         struct ceph_msg *msg;
2044         int flags = 0;
2045
2046         req->r_attempts++;
2047         if (req->r_inode) {
2048                 struct ceph_cap *cap =
2049                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2050
2051                 if (cap)
2052                         req->r_sent_on_mseq = cap->mseq;
2053                 else
2054                         req->r_sent_on_mseq = -1;
2055         }
2056         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2057              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2058
2059         if (req->r_got_unsafe) {
2060                 void *p;
2061                 /*
2062                  * Replay.  Do not regenerate message (and rebuild
2063                  * paths, etc.); just use the original message.
2064                  * Rebuilding paths will break for renames because
2065                  * d_move mangles the src name.
2066                  */
2067                 msg = req->r_request;
2068                 rhead = msg->front.iov_base;
2069
2070                 flags = le32_to_cpu(rhead->flags);
2071                 flags |= CEPH_MDS_FLAG_REPLAY;
2072                 rhead->flags = cpu_to_le32(flags);
2073
2074                 if (req->r_target_inode)
2075                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2076
2077                 rhead->num_retry = req->r_attempts - 1;
2078
2079                 /* remove cap/dentry releases from message */
2080                 rhead->num_releases = 0;
2081
2082                 /* time stamp */
2083                 p = msg->front.iov_base + req->r_request_release_offset;
2084                 {
2085                         struct ceph_timespec ts;
2086                         ceph_encode_timespec(&ts, &req->r_stamp);
2087                         ceph_encode_copy(&p, &ts, sizeof(ts));
2088                 }
2089
2090                 msg->front.iov_len = p - msg->front.iov_base;
2091                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2092                 return 0;
2093         }
2094
2095         if (req->r_request) {
2096                 ceph_msg_put(req->r_request);
2097                 req->r_request = NULL;
2098         }
2099         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2100         if (IS_ERR(msg)) {
2101                 req->r_err = PTR_ERR(msg);
2102                 complete_request(mdsc, req);
2103                 return PTR_ERR(msg);
2104         }
2105         req->r_request = msg;
2106
2107         rhead = msg->front.iov_base;
2108         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2109         if (req->r_got_unsafe)
2110                 flags |= CEPH_MDS_FLAG_REPLAY;
2111         if (req->r_locked_dir)
2112                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2113         rhead->flags = cpu_to_le32(flags);
2114         rhead->num_fwd = req->r_num_fwd;
2115         rhead->num_retry = req->r_attempts - 1;
2116         rhead->ino = 0;
2117
2118         dout(" r_locked_dir = %p\n", req->r_locked_dir);
2119         return 0;
2120 }
2121
2122 /*
2123  * send request, or put it on the appropriate wait list.
2124  */
2125 static int __do_request(struct ceph_mds_client *mdsc,
2126                         struct ceph_mds_request *req)
2127 {
2128         struct ceph_mds_session *session = NULL;
2129         int mds = -1;
2130         int err = -EAGAIN;
2131
2132         if (req->r_err || req->r_got_result) {
2133                 if (req->r_aborted)
2134                         __unregister_request(mdsc, req);
2135                 goto out;
2136         }
2137
2138         if (req->r_timeout &&
2139             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2140                 dout("do_request timed out\n");
2141                 err = -EIO;
2142                 goto finish;
2143         }
2144
2145         put_request_session(req);
2146
2147         mds = __choose_mds(mdsc, req);
2148         if (mds < 0 ||
2149             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2150                 dout("do_request no mds or not active, waiting for map\n");
2151                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2152                 goto out;
2153         }
2154
2155         /* get, open session */
2156         session = __ceph_lookup_mds_session(mdsc, mds);
2157         if (!session) {
2158                 session = register_session(mdsc, mds);
2159                 if (IS_ERR(session)) {
2160                         err = PTR_ERR(session);
2161                         goto finish;
2162                 }
2163         }
2164         req->r_session = get_session(session);
2165
2166         dout("do_request mds%d session %p state %s\n", mds, session,
2167              ceph_session_state_name(session->s_state));
2168         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2169             session->s_state != CEPH_MDS_SESSION_HUNG) {
2170                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2171                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2172                         __open_session(mdsc, session);
2173                 list_add(&req->r_wait, &session->s_waiting);
2174                 goto out_session;
2175         }
2176
2177         /* send request */
2178         req->r_resend_mds = -1;   /* forget any previous mds hint */
2179
2180         if (req->r_request_started == 0)   /* note request start time */
2181                 req->r_request_started = jiffies;
2182
2183         err = __prepare_send_request(mdsc, req, mds, false);
2184         if (!err) {
2185                 ceph_msg_get(req->r_request);
2186                 ceph_con_send(&session->s_con, req->r_request);
2187         }
2188
2189 out_session:
2190         ceph_put_mds_session(session);
2191 out:
2192         return err;
2193
2194 finish:
2195         req->r_err = err;
2196         complete_request(mdsc, req);
2197         goto out;
2198 }
2199
2200 /*
2201  * called under mdsc->mutex
2202  */
2203 static void __wake_requests(struct ceph_mds_client *mdsc,
2204                             struct list_head *head)
2205 {
2206         struct ceph_mds_request *req;
2207         LIST_HEAD(tmp_list);
2208
2209         list_splice_init(head, &tmp_list);
2210
2211         while (!list_empty(&tmp_list)) {
2212                 req = list_entry(tmp_list.next,
2213                                  struct ceph_mds_request, r_wait);
2214                 list_del_init(&req->r_wait);
2215                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2216                 __do_request(mdsc, req);
2217         }
2218 }
2219
2220 /*
2221  * Wake up threads with requests pending for @mds, so that they can
2222  * resubmit their requests to a possibly different mds.
2223  */
2224 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2225 {
2226         struct ceph_mds_request *req;
2227         struct rb_node *p = rb_first(&mdsc->request_tree);
2228
2229         dout("kick_requests mds%d\n", mds);
2230         while (p) {
2231                 req = rb_entry(p, struct ceph_mds_request, r_node);
2232                 p = rb_next(p);
2233                 if (req->r_got_unsafe)
2234                         continue;
2235                 if (req->r_attempts > 0)
2236                         continue; /* only new requests */
2237                 if (req->r_session &&
2238                     req->r_session->s_mds == mds) {
2239                         dout(" kicking tid %llu\n", req->r_tid);
2240                         list_del_init(&req->r_wait);
2241                         __do_request(mdsc, req);
2242                 }
2243         }
2244 }
2245
2246 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2247                               struct ceph_mds_request *req)
2248 {
2249         dout("submit_request on %p\n", req);
2250         mutex_lock(&mdsc->mutex);
2251         __register_request(mdsc, req, NULL);
2252         __do_request(mdsc, req);
2253         mutex_unlock(&mdsc->mutex);
2254 }
2255
2256 /*
2257  * Synchrously perform an mds request.  Take care of all of the
2258  * session setup, forwarding, retry details.
2259  */
2260 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2261                          struct inode *dir,
2262                          struct ceph_mds_request *req)
2263 {
2264         int err;
2265
2266         dout("do_request on %p\n", req);
2267
2268         /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2269         if (req->r_inode)
2270                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2271         if (req->r_locked_dir)
2272                 ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2273         if (req->r_old_dentry_dir)
2274                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2275                                   CEPH_CAP_PIN);
2276
2277         /* issue */
2278         mutex_lock(&mdsc->mutex);
2279         __register_request(mdsc, req, dir);
2280         __do_request(mdsc, req);
2281
2282         if (req->r_err) {
2283                 err = req->r_err;
2284                 __unregister_request(mdsc, req);
2285                 dout("do_request early error %d\n", err);
2286                 goto out;
2287         }
2288
2289         /* wait */
2290         mutex_unlock(&mdsc->mutex);
2291         dout("do_request waiting\n");
2292         if (!req->r_timeout && req->r_wait_for_completion) {
2293                 err = req->r_wait_for_completion(mdsc, req);
2294         } else {
2295                 long timeleft = wait_for_completion_killable_timeout(
2296                                         &req->r_completion,
2297                                         ceph_timeout_jiffies(req->r_timeout));
2298                 if (timeleft > 0)
2299                         err = 0;
2300                 else if (!timeleft)
2301                         err = -EIO;  /* timed out */
2302                 else
2303                         err = timeleft;  /* killed */
2304         }
2305         dout("do_request waited, got %d\n", err);
2306         mutex_lock(&mdsc->mutex);
2307
2308         /* only abort if we didn't race with a real reply */
2309         if (req->r_got_result) {
2310                 err = le32_to_cpu(req->r_reply_info.head->result);
2311         } else if (err < 0) {
2312                 dout("aborted request %lld with %d\n", req->r_tid, err);
2313
2314                 /*
2315                  * ensure we aren't running concurrently with
2316                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2317                  * rely on locks (dir mutex) held by our caller.
2318                  */
2319                 mutex_lock(&req->r_fill_mutex);
2320                 req->r_err = err;
2321                 req->r_aborted = true;
2322                 mutex_unlock(&req->r_fill_mutex);
2323
2324                 if (req->r_locked_dir &&
2325                     (req->r_op & CEPH_MDS_OP_WRITE))
2326                         ceph_invalidate_dir_request(req);
2327         } else {
2328                 err = req->r_err;
2329         }
2330
2331 out:
2332         mutex_unlock(&mdsc->mutex);
2333         dout("do_request %p done, result %d\n", req, err);
2334         return err;
2335 }
2336
2337 /*
2338  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2339  * namespace request.
2340  */
2341 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2342 {
2343         struct inode *inode = req->r_locked_dir;
2344
2345         dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2346
2347         ceph_dir_clear_complete(inode);
2348         if (req->r_dentry)
2349                 ceph_invalidate_dentry_lease(req->r_dentry);
2350         if (req->r_old_dentry)
2351                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2352 }
2353
2354 /*
2355  * Handle mds reply.
2356  *
2357  * We take the session mutex and parse and process the reply immediately.
2358  * This preserves the logical ordering of replies, capabilities, etc., sent
2359  * by the MDS as they are applied to our local cache.
2360  */
2361 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2362 {
2363         struct ceph_mds_client *mdsc = session->s_mdsc;
2364         struct ceph_mds_request *req;
2365         struct ceph_mds_reply_head *head = msg->front.iov_base;
2366         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2367         struct ceph_snap_realm *realm;
2368         u64 tid;
2369         int err, result;
2370         int mds = session->s_mds;
2371
2372         if (msg->front.iov_len < sizeof(*head)) {
2373                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2374                 ceph_msg_dump(msg);
2375                 return;
2376         }
2377
2378         /* get request, session */
2379         tid = le64_to_cpu(msg->hdr.tid);
2380         mutex_lock(&mdsc->mutex);
2381         req = __lookup_request(mdsc, tid);
2382         if (!req) {
2383                 dout("handle_reply on unknown tid %llu\n", tid);
2384                 mutex_unlock(&mdsc->mutex);
2385                 return;
2386         }
2387         dout("handle_reply %p\n", req);
2388
2389         /* correct session? */
2390         if (req->r_session != session) {
2391                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2392                        " not mds%d\n", tid, session->s_mds,
2393                        req->r_session ? req->r_session->s_mds : -1);
2394                 mutex_unlock(&mdsc->mutex);
2395                 goto out;
2396         }
2397
2398         /* dup? */
2399         if ((req->r_got_unsafe && !head->safe) ||
2400             (req->r_got_safe && head->safe)) {
2401                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2402                            head->safe ? "safe" : "unsafe", tid, mds);
2403                 mutex_unlock(&mdsc->mutex);
2404                 goto out;
2405         }
2406         if (req->r_got_safe && !head->safe) {
2407                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2408                            tid, mds);
2409                 mutex_unlock(&mdsc->mutex);
2410                 goto out;
2411         }
2412
2413         result = le32_to_cpu(head->result);
2414
2415         /*
2416          * Handle an ESTALE
2417          * if we're not talking to the authority, send to them
2418          * if the authority has changed while we weren't looking,
2419          * send to new authority
2420          * Otherwise we just have to return an ESTALE
2421          */
2422         if (result == -ESTALE) {
2423                 dout("got ESTALE on request %llu", req->r_tid);
2424                 req->r_resend_mds = -1;
2425                 if (req->r_direct_mode != USE_AUTH_MDS) {
2426                         dout("not using auth, setting for that now");
2427                         req->r_direct_mode = USE_AUTH_MDS;
2428                         __do_request(mdsc, req);
2429                         mutex_unlock(&mdsc->mutex);
2430                         goto out;
2431                 } else  {
2432                         int mds = __choose_mds(mdsc, req);
2433                         if (mds >= 0 && mds != req->r_session->s_mds) {
2434                                 dout("but auth changed, so resending");
2435                                 __do_request(mdsc, req);
2436                                 mutex_unlock(&mdsc->mutex);
2437                                 goto out;
2438                         }
2439                 }
2440                 dout("have to return ESTALE on request %llu", req->r_tid);
2441         }
2442
2443
2444         if (head->safe) {
2445                 req->r_got_safe = true;
2446                 __unregister_request(mdsc, req);
2447
2448                 if (req->r_got_unsafe) {
2449                         /*
2450                          * We already handled the unsafe response, now do the
2451                          * cleanup.  No need to examine the response; the MDS
2452                          * doesn't include any result info in the safe
2453                          * response.  And even if it did, there is nothing
2454                          * useful we could do with a revised return value.
2455                          */
2456                         dout("got safe reply %llu, mds%d\n", tid, mds);
2457                         list_del_init(&req->r_unsafe_item);
2458
2459                         /* last unsafe request during umount? */
2460                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2461                                 complete_all(&mdsc->safe_umount_waiters);
2462                         mutex_unlock(&mdsc->mutex);
2463                         goto out;
2464                 }
2465         } else {
2466                 req->r_got_unsafe = true;
2467                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2468         }
2469
2470         dout("handle_reply tid %lld result %d\n", tid, result);
2471         rinfo = &req->r_reply_info;
2472         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2473         mutex_unlock(&mdsc->mutex);
2474
2475         mutex_lock(&session->s_mutex);
2476         if (err < 0) {
2477                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2478                 ceph_msg_dump(msg);
2479                 goto out_err;
2480         }
2481
2482         /* snap trace */
2483         realm = NULL;
2484         if (rinfo->snapblob_len) {
2485                 down_write(&mdsc->snap_rwsem);
2486                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2487                                 rinfo->snapblob + rinfo->snapblob_len,
2488                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2489                                 &realm);
2490                 downgrade_write(&mdsc->snap_rwsem);
2491         } else {
2492                 down_read(&mdsc->snap_rwsem);
2493         }
2494
2495         /* insert trace into our cache */
2496         mutex_lock(&req->r_fill_mutex);
2497         err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2498         if (err == 0) {
2499                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2500                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2501                         ceph_readdir_prepopulate(req, req->r_session);
2502                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2503         }
2504         mutex_unlock(&req->r_fill_mutex);
2505
2506         up_read(&mdsc->snap_rwsem);
2507         if (realm)
2508                 ceph_put_snap_realm(mdsc, realm);
2509 out_err:
2510         mutex_lock(&mdsc->mutex);
2511         if (!req->r_aborted) {
2512                 if (err) {
2513                         req->r_err = err;
2514                 } else {
2515                         req->r_reply = msg;
2516                         ceph_msg_get(msg);
2517                         req->r_got_result = true;
2518                 }
2519         } else {
2520                 dout("reply arrived after request %lld was aborted\n", tid);
2521         }
2522         mutex_unlock(&mdsc->mutex);
2523
2524         mutex_unlock(&session->s_mutex);
2525
2526         /* kick calling process */
2527         complete_request(mdsc, req);
2528 out:
2529         ceph_mdsc_put_request(req);
2530         return;
2531 }
2532
2533
2534
2535 /*
2536  * handle mds notification that our request has been forwarded.
2537  */
2538 static void handle_forward(struct ceph_mds_client *mdsc,
2539                            struct ceph_mds_session *session,
2540                            struct ceph_msg *msg)
2541 {
2542         struct ceph_mds_request *req;
2543         u64 tid = le64_to_cpu(msg->hdr.tid);
2544         u32 next_mds;
2545         u32 fwd_seq;
2546         int err = -EINVAL;
2547         void *p = msg->front.iov_base;
2548         void *end = p + msg->front.iov_len;
2549
2550         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2551         next_mds = ceph_decode_32(&p);
2552         fwd_seq = ceph_decode_32(&p);
2553
2554         mutex_lock(&mdsc->mutex);
2555         req = __lookup_request(mdsc, tid);
2556         if (!req) {
2557                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2558                 goto out;  /* dup reply? */
2559         }
2560
2561         if (req->r_aborted) {
2562                 dout("forward tid %llu aborted, unregistering\n", tid);
2563                 __unregister_request(mdsc, req);
2564         } else if (fwd_seq <= req->r_num_fwd) {
2565                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2566                      tid, next_mds, req->r_num_fwd, fwd_seq);
2567         } else {
2568                 /* resend. forward race not possible; mds would drop */
2569                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2570                 BUG_ON(req->r_err);
2571                 BUG_ON(req->r_got_result);
2572                 req->r_attempts = 0;
2573                 req->r_num_fwd = fwd_seq;
2574                 req->r_resend_mds = next_mds;
2575                 put_request_session(req);
2576                 __do_request(mdsc, req);
2577         }
2578         ceph_mdsc_put_request(req);
2579 out:
2580         mutex_unlock(&mdsc->mutex);
2581         return;
2582
2583 bad:
2584         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2585 }
2586
2587 /*
2588  * handle a mds session control message
2589  */
2590 static void handle_session(struct ceph_mds_session *session,
2591                            struct ceph_msg *msg)
2592 {
2593         struct ceph_mds_client *mdsc = session->s_mdsc;
2594         u32 op;
2595         u64 seq;
2596         int mds = session->s_mds;
2597         struct ceph_mds_session_head *h = msg->front.iov_base;
2598         int wake = 0;
2599
2600         /* decode */
2601         if (msg->front.iov_len != sizeof(*h))
2602                 goto bad;
2603         op = le32_to_cpu(h->op);
2604         seq = le64_to_cpu(h->seq);
2605
2606         mutex_lock(&mdsc->mutex);
2607         if (op == CEPH_SESSION_CLOSE)
2608                 __unregister_session(mdsc, session);
2609         /* FIXME: this ttl calculation is generous */
2610         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2611         mutex_unlock(&mdsc->mutex);
2612
2613         mutex_lock(&session->s_mutex);
2614
2615         dout("handle_session mds%d %s %p state %s seq %llu\n",
2616              mds, ceph_session_op_name(op), session,
2617              ceph_session_state_name(session->s_state), seq);
2618
2619         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2620                 session->s_state = CEPH_MDS_SESSION_OPEN;
2621                 pr_info("mds%d came back\n", session->s_mds);
2622         }
2623
2624         switch (op) {
2625         case CEPH_SESSION_OPEN:
2626                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2627                         pr_info("mds%d reconnect success\n", session->s_mds);
2628                 session->s_state = CEPH_MDS_SESSION_OPEN;
2629                 renewed_caps(mdsc, session, 0);
2630                 wake = 1;
2631                 if (mdsc->stopping)
2632                         __close_session(mdsc, session);
2633                 break;
2634
2635         case CEPH_SESSION_RENEWCAPS:
2636                 if (session->s_renew_seq == seq)
2637                         renewed_caps(mdsc, session, 1);
2638                 break;
2639
2640         case CEPH_SESSION_CLOSE:
2641                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2642                         pr_info("mds%d reconnect denied\n", session->s_mds);
2643                 cleanup_session_requests(mdsc, session);
2644                 remove_session_caps(session);
2645                 wake = 2; /* for good measure */
2646                 wake_up_all(&mdsc->session_close_wq);
2647                 break;
2648
2649         case CEPH_SESSION_STALE:
2650                 pr_info("mds%d caps went stale, renewing\n",
2651                         session->s_mds);
2652                 spin_lock(&session->s_gen_ttl_lock);
2653                 session->s_cap_gen++;
2654                 session->s_cap_ttl = jiffies - 1;
2655                 spin_unlock(&session->s_gen_ttl_lock);
2656                 send_renew_caps(mdsc, session);
2657                 break;
2658
2659         case CEPH_SESSION_RECALL_STATE:
2660                 trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2661                 break;
2662
2663         case CEPH_SESSION_FLUSHMSG:
2664                 send_flushmsg_ack(mdsc, session, seq);
2665                 break;
2666
2667         case CEPH_SESSION_FORCE_RO:
2668                 dout("force_session_readonly %p\n", session);
2669                 spin_lock(&session->s_cap_lock);
2670                 session->s_readonly = true;
2671                 spin_unlock(&session->s_cap_lock);
2672                 wake_up_session_caps(session, 0);
2673                 break;
2674
2675         default:
2676                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2677                 WARN_ON(1);
2678         }
2679
2680         mutex_unlock(&session->s_mutex);
2681         if (wake) {
2682                 mutex_lock(&mdsc->mutex);
2683                 __wake_requests(mdsc, &session->s_waiting);
2684                 if (wake == 2)
2685                         kick_requests(mdsc, mds);
2686                 mutex_unlock(&mdsc->mutex);
2687         }
2688         return;
2689
2690 bad:
2691         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2692                (int)msg->front.iov_len);
2693         ceph_msg_dump(msg);
2694         return;
2695 }
2696
2697
2698 /*
2699  * called under session->mutex.
2700  */
2701 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2702                                    struct ceph_mds_session *session)
2703 {
2704         struct ceph_mds_request *req, *nreq;
2705         struct rb_node *p;
2706         int err;
2707
2708         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2709
2710         mutex_lock(&mdsc->mutex);
2711         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2712                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
2713                 if (!err) {
2714                         ceph_msg_get(req->r_request);
2715                         ceph_con_send(&session->s_con, req->r_request);
2716                 }
2717         }
2718
2719         /*
2720          * also re-send old requests when MDS enters reconnect stage. So that MDS
2721          * can process completed request in clientreplay stage.
2722          */
2723         p = rb_first(&mdsc->request_tree);
2724         while (p) {
2725                 req = rb_entry(p, struct ceph_mds_request, r_node);
2726                 p = rb_next(p);
2727                 if (req->r_got_unsafe)
2728                         continue;
2729                 if (req->r_attempts == 0)
2730                         continue; /* only old requests */
2731                 if (req->r_session &&
2732                     req->r_session->s_mds == session->s_mds) {
2733                         err = __prepare_send_request(mdsc, req,
2734                                                      session->s_mds, true);
2735                         if (!err) {
2736                                 ceph_msg_get(req->r_request);
2737                                 ceph_con_send(&session->s_con, req->r_request);
2738                         }
2739                 }
2740         }
2741         mutex_unlock(&mdsc->mutex);
2742 }
2743
2744 /*
2745  * Encode information about a cap for a reconnect with the MDS.
2746  */
2747 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2748                           void *arg)
2749 {
2750         union {
2751                 struct ceph_mds_cap_reconnect v2;
2752                 struct ceph_mds_cap_reconnect_v1 v1;
2753         } rec;
2754         size_t reclen;
2755         struct ceph_inode_info *ci;
2756         struct ceph_reconnect_state *recon_state = arg;
2757         struct ceph_pagelist *pagelist = recon_state->pagelist;
2758         char *path;
2759         int pathlen, err;
2760         u64 pathbase;
2761         struct dentry *dentry;
2762
2763         ci = cap->ci;
2764
2765         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2766              inode, ceph_vinop(inode), cap, cap->cap_id,
2767              ceph_cap_string(cap->issued));
2768         err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2769         if (err)
2770                 return err;
2771
2772         dentry = d_find_alias(inode);
2773         if (dentry) {
2774                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2775                 if (IS_ERR(path)) {
2776                         err = PTR_ERR(path);
2777                         goto out_dput;
2778                 }
2779         } else {
2780                 path = NULL;
2781                 pathlen = 0;
2782         }
2783         err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2784         if (err)
2785                 goto out_free;
2786
2787         spin_lock(&ci->i_ceph_lock);
2788         cap->seq = 0;        /* reset cap seq */
2789         cap->issue_seq = 0;  /* and issue_seq */
2790         cap->mseq = 0;       /* and migrate_seq */
2791         cap->cap_gen = cap->session->s_cap_gen;
2792
2793         if (recon_state->flock) {
2794                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2795                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2796                 rec.v2.issued = cpu_to_le32(cap->issued);
2797                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2798                 rec.v2.pathbase = cpu_to_le64(pathbase);
2799                 rec.v2.flock_len = 0;
2800                 reclen = sizeof(rec.v2);
2801         } else {
2802                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2803                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2804                 rec.v1.issued = cpu_to_le32(cap->issued);
2805                 rec.v1.size = cpu_to_le64(inode->i_size);
2806                 ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2807                 ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2808                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2809                 rec.v1.pathbase = cpu_to_le64(pathbase);
2810                 reclen = sizeof(rec.v1);
2811         }
2812         spin_unlock(&ci->i_ceph_lock);
2813
2814         if (recon_state->flock) {
2815                 int num_fcntl_locks, num_flock_locks;
2816                 struct ceph_filelock *flocks;
2817
2818 encode_again:
2819                 ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2820                 flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2821                                  sizeof(struct ceph_filelock), GFP_NOFS);
2822                 if (!flocks) {
2823                         err = -ENOMEM;
2824                         goto out_free;
2825                 }
2826                 err = ceph_encode_locks_to_buffer(inode, flocks,
2827                                                   num_fcntl_locks,
2828                                                   num_flock_locks);
2829                 if (err) {
2830                         kfree(flocks);
2831                         if (err == -ENOSPC)
2832                                 goto encode_again;
2833                         goto out_free;
2834                 }
2835                 /*
2836                  * number of encoded locks is stable, so copy to pagelist
2837                  */
2838                 rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2839                                     (num_fcntl_locks+num_flock_locks) *
2840                                     sizeof(struct ceph_filelock));
2841                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2842                 if (!err)
2843                         err = ceph_locks_to_pagelist(flocks, pagelist,
2844                                                      num_fcntl_locks,
2845                                                      num_flock_locks);
2846                 kfree(flocks);
2847         } else {
2848                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2849         }
2850
2851         recon_state->nr_caps++;
2852 out_free:
2853         kfree(path);
2854 out_dput:
2855         dput(dentry);
2856         return err;
2857 }
2858
2859
2860 /*
2861  * If an MDS fails and recovers, clients need to reconnect in order to
2862  * reestablish shared state.  This includes all caps issued through
2863  * this session _and_ the snap_realm hierarchy.  Because it's not
2864  * clear which snap realms the mds cares about, we send everything we
2865  * know about.. that ensures we'll then get any new info the
2866  * recovering MDS might have.
2867  *
2868  * This is a relatively heavyweight operation, but it's rare.
2869  *
2870  * called with mdsc->mutex held.
2871  */
2872 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2873                                struct ceph_mds_session *session)
2874 {
2875         struct ceph_msg *reply;
2876         struct rb_node *p;
2877         int mds = session->s_mds;
2878         int err = -ENOMEM;
2879         int s_nr_caps;
2880         struct ceph_pagelist *pagelist;
2881         struct ceph_reconnect_state recon_state;
2882
2883         pr_info("mds%d reconnect start\n", mds);
2884
2885         pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2886         if (!pagelist)
2887                 goto fail_nopagelist;
2888         ceph_pagelist_init(pagelist);
2889
2890         reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2891         if (!reply)
2892                 goto fail_nomsg;
2893
2894         mutex_lock(&session->s_mutex);
2895         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2896         session->s_seq = 0;
2897
2898         dout("session %p state %s\n", session,
2899              ceph_session_state_name(session->s_state));
2900
2901         spin_lock(&session->s_gen_ttl_lock);
2902         session->s_cap_gen++;
2903         spin_unlock(&session->s_gen_ttl_lock);
2904
2905         spin_lock(&session->s_cap_lock);
2906         /* don't know if session is readonly */
2907         session->s_readonly = 0;
2908         /*
2909          * notify __ceph_remove_cap() that we are composing cap reconnect.
2910          * If a cap get released before being added to the cap reconnect,
2911          * __ceph_remove_cap() should skip queuing cap release.
2912          */
2913         session->s_cap_reconnect = 1;
2914         /* drop old cap expires; we're about to reestablish that state */
2915         cleanup_cap_releases(mdsc, session);
2916
2917         /* trim unused caps to reduce MDS's cache rejoin time */
2918         if (mdsc->fsc->sb->s_root)
2919                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
2920
2921         ceph_con_close(&session->s_con);
2922         ceph_con_open(&session->s_con,
2923                       CEPH_ENTITY_TYPE_MDS, mds,
2924                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2925
2926         /* replay unsafe requests */
2927         replay_unsafe_requests(mdsc, session);
2928
2929         down_read(&mdsc->snap_rwsem);
2930
2931         /* traverse this session's caps */
2932         s_nr_caps = session->s_nr_caps;
2933         err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2934         if (err)
2935                 goto fail;
2936
2937         recon_state.nr_caps = 0;
2938         recon_state.pagelist = pagelist;
2939         recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2940         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2941         if (err < 0)
2942                 goto fail;
2943
2944         spin_lock(&session->s_cap_lock);
2945         session->s_cap_reconnect = 0;
2946         spin_unlock(&session->s_cap_lock);
2947
2948         /*
2949          * snaprealms.  we provide mds with the ino, seq (version), and
2950          * parent for all of our realms.  If the mds has any newer info,
2951          * it will tell us.
2952          */
2953         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2954                 struct ceph_snap_realm *realm =
2955                         rb_entry(p, struct ceph_snap_realm, node);
2956                 struct ceph_mds_snaprealm_reconnect sr_rec;
2957
2958                 dout(" adding snap realm %llx seq %lld parent %llx\n",
2959                      realm->ino, realm->seq, realm->parent_ino);
2960                 sr_rec.ino = cpu_to_le64(realm->ino);
2961                 sr_rec.seq = cpu_to_le64(realm->seq);
2962                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
2963                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2964                 if (err)
2965                         goto fail;
2966         }
2967
2968         if (recon_state.flock)
2969                 reply->hdr.version = cpu_to_le16(2);
2970
2971         /* raced with cap release? */
2972         if (s_nr_caps != recon_state.nr_caps) {
2973                 struct page *page = list_first_entry(&pagelist->head,
2974                                                      struct page, lru);
2975                 __le32 *addr = kmap_atomic(page);
2976                 *addr = cpu_to_le32(recon_state.nr_caps);
2977                 kunmap_atomic(addr);
2978         }
2979
2980         reply->hdr.data_len = cpu_to_le32(pagelist->length);
2981         ceph_msg_data_add_pagelist(reply, pagelist);
2982         ceph_con_send(&session->s_con, reply);
2983
2984         mutex_unlock(&session->s_mutex);
2985
2986         mutex_lock(&mdsc->mutex);
2987         __wake_requests(mdsc, &session->s_waiting);
2988         mutex_unlock(&mdsc->mutex);
2989
2990         up_read(&mdsc->snap_rwsem);
2991         return;
2992
2993 fail:
2994         ceph_msg_put(reply);
2995         up_read(&mdsc->snap_rwsem);
2996         mutex_unlock(&session->s_mutex);
2997 fail_nomsg:
2998         ceph_pagelist_release(pagelist);
2999 fail_nopagelist:
3000         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3001         return;
3002 }
3003
3004
3005 /*
3006  * compare old and new mdsmaps, kicking requests
3007  * and closing out old connections as necessary
3008  *
3009  * called under mdsc->mutex.
3010  */
3011 static void check_new_map(struct ceph_mds_client *mdsc,
3012                           struct ceph_mdsmap *newmap,
3013                           struct ceph_mdsmap *oldmap)
3014 {
3015         int i;
3016         int oldstate, newstate;
3017         struct ceph_mds_session *s;
3018
3019         dout("check_new_map new %u old %u\n",
3020              newmap->m_epoch, oldmap->m_epoch);
3021
3022         for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
3023                 if (mdsc->sessions[i] == NULL)
3024                         continue;
3025                 s = mdsc->sessions[i];
3026                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3027                 newstate = ceph_mdsmap_get_state(newmap, i);
3028
3029                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3030                      i, ceph_mds_state_name(oldstate),
3031                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3032                      ceph_mds_state_name(newstate),
3033                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3034                      ceph_session_state_name(s->s_state));
3035
3036                 if (i >= newmap->m_max_mds ||
3037                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
3038                            ceph_mdsmap_get_addr(newmap, i),
3039                            sizeof(struct ceph_entity_addr))) {
3040                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
3041                                 /* the session never opened, just close it
3042                                  * out now */
3043                                 __wake_requests(mdsc, &s->s_waiting);
3044                                 __unregister_session(mdsc, s);
3045                         } else {
3046                                 /* just close it */
3047                                 mutex_unlock(&mdsc->mutex);
3048                                 mutex_lock(&s->s_mutex);
3049                                 mutex_lock(&mdsc->mutex);
3050                                 ceph_con_close(&s->s_con);
3051                                 mutex_unlock(&s->s_mutex);
3052                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
3053                         }
3054                 } else if (oldstate == newstate) {
3055                         continue;  /* nothing new with this mds */
3056                 }
3057
3058                 /*
3059                  * send reconnect?
3060                  */
3061                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3062                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3063                         mutex_unlock(&mdsc->mutex);
3064                         send_mds_reconnect(mdsc, s);
3065                         mutex_lock(&mdsc->mutex);
3066                 }
3067
3068                 /*
3069                  * kick request on any mds that has gone active.
3070                  */
3071                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3072                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3073                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3074                             oldstate != CEPH_MDS_STATE_STARTING)
3075                                 pr_info("mds%d recovery completed\n", s->s_mds);
3076                         kick_requests(mdsc, i);
3077                         ceph_kick_flushing_caps(mdsc, s);
3078                         wake_up_session_caps(s, 1);
3079                 }
3080         }
3081
3082         for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3083                 s = mdsc->sessions[i];
3084                 if (!s)
3085                         continue;
3086                 if (!ceph_mdsmap_is_laggy(newmap, i))
3087                         continue;
3088                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3089                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3090                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3091                         dout(" connecting to export targets of laggy mds%d\n",
3092                              i);
3093                         __open_export_target_sessions(mdsc, s);
3094                 }
3095         }
3096 }
3097
3098
3099
3100 /*
3101  * leases
3102  */
3103
3104 /*
3105  * caller must hold session s_mutex, dentry->d_lock
3106  */
3107 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3108 {
3109         struct ceph_dentry_info *di = ceph_dentry(dentry);
3110
3111         ceph_put_mds_session(di->lease_session);
3112         di->lease_session = NULL;
3113 }
3114
3115 static void handle_lease(struct ceph_mds_client *mdsc,
3116                          struct ceph_mds_session *session,
3117                          struct ceph_msg *msg)
3118 {
3119         struct super_block *sb = mdsc->fsc->sb;
3120         struct inode *inode;
3121         struct dentry *parent, *dentry;
3122         struct ceph_dentry_info *di;
3123         int mds = session->s_mds;
3124         struct ceph_mds_lease *h = msg->front.iov_base;
3125         u32 seq;
3126         struct ceph_vino vino;
3127         struct qstr dname;
3128         int release = 0;
3129
3130         dout("handle_lease from mds%d\n", mds);
3131
3132         /* decode */
3133         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3134                 goto bad;
3135         vino.ino = le64_to_cpu(h->ino);
3136         vino.snap = CEPH_NOSNAP;
3137         seq = le32_to_cpu(h->seq);
3138         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3139         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3140         if (dname.len != get_unaligned_le32(h+1))
3141                 goto bad;
3142
3143         /* lookup inode */
3144         inode = ceph_find_inode(sb, vino);
3145         dout("handle_lease %s, ino %llx %p %.*s\n",
3146              ceph_lease_op_name(h->action), vino.ino, inode,
3147              dname.len, dname.name);
3148
3149         mutex_lock(&session->s_mutex);
3150         session->s_seq++;
3151
3152         if (inode == NULL) {
3153                 dout("handle_lease no inode %llx\n", vino.ino);
3154                 goto release;
3155         }
3156
3157         /* dentry */
3158         parent = d_find_alias(inode);
3159         if (!parent) {
3160                 dout("no parent dentry on inode %p\n", inode);
3161                 WARN_ON(1);
3162                 goto release;  /* hrm... */
3163         }
3164         dname.hash = full_name_hash(dname.name, dname.len);
3165         dentry = d_lookup(parent, &dname);
3166         dput(parent);
3167         if (!dentry)
3168                 goto release;
3169
3170         spin_lock(&dentry->d_lock);
3171         di = ceph_dentry(dentry);
3172         switch (h->action) {
3173         case CEPH_MDS_LEASE_REVOKE:
3174                 if (di->lease_session == session) {
3175                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3176                                 h->seq = cpu_to_le32(di->lease_seq);
3177                         __ceph_mdsc_drop_dentry_lease(dentry);
3178                 }
3179                 release = 1;
3180                 break;
3181
3182         case CEPH_MDS_LEASE_RENEW:
3183                 if (di->lease_session == session &&
3184                     di->lease_gen == session->s_cap_gen &&
3185                     di->lease_renew_from &&
3186                     di->lease_renew_after == 0) {
3187                         unsigned long duration =
3188                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3189
3190                         di->lease_seq = seq;
3191                         dentry->d_time = di->lease_renew_from + duration;
3192                         di->lease_renew_after = di->lease_renew_from +
3193                                 (duration >> 1);
3194                         di->lease_renew_from = 0;
3195                 }
3196                 break;
3197         }
3198         spin_unlock(&dentry->d_lock);
3199         dput(dentry);
3200
3201         if (!release)
3202                 goto out;
3203
3204 release:
3205         /* let's just reuse the same message */
3206         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3207         ceph_msg_get(msg);
3208         ceph_con_send(&session->s_con, msg);
3209
3210 out:
3211         iput(inode);
3212         mutex_unlock(&session->s_mutex);
3213         return;
3214
3215 bad:
3216         pr_err("corrupt lease message\n");
3217         ceph_msg_dump(msg);
3218 }
3219
3220 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3221                               struct inode *inode,
3222                               struct dentry *dentry, char action,
3223                               u32 seq)
3224 {
3225         struct ceph_msg *msg;
3226         struct ceph_mds_lease *lease;
3227         int len = sizeof(*lease) + sizeof(u32);
3228         int dnamelen = 0;
3229
3230         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3231              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3232         dnamelen = dentry->d_name.len;
3233         len += dnamelen;
3234
3235         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3236         if (!msg)
3237                 return;
3238         lease = msg->front.iov_base;
3239         lease->action = action;
3240         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3241         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3242         lease->seq = cpu_to_le32(seq);
3243         put_unaligned_le32(dnamelen, lease + 1);
3244         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3245
3246         /*
3247          * if this is a preemptive lease RELEASE, no need to
3248          * flush request stream, since the actual request will
3249          * soon follow.
3250          */
3251         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3252
3253         ceph_con_send(&session->s_con, msg);
3254 }
3255
3256 /*
3257  * Preemptively release a lease we expect to invalidate anyway.
3258  * Pass @inode always, @dentry is optional.
3259  */
3260 void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
3261                              struct dentry *dentry)
3262 {
3263         struct ceph_dentry_info *di;
3264         struct ceph_mds_session *session;
3265         u32 seq;
3266
3267         BUG_ON(inode == NULL);
3268         BUG_ON(dentry == NULL);
3269
3270         /* is dentry lease valid? */
3271         spin_lock(&dentry->d_lock);
3272         di = ceph_dentry(dentry);
3273         if (!di || !di->lease_session ||
3274             di->lease_session->s_mds < 0 ||
3275             di->lease_gen != di->lease_session->s_cap_gen ||
3276             !time_before(jiffies, dentry->d_time)) {
3277                 dout("lease_release inode %p dentry %p -- "
3278                      "no lease\n",
3279                      inode, dentry);
3280                 spin_unlock(&dentry->d_lock);
3281                 return;
3282         }
3283
3284         /* we do have a lease on this dentry; note mds and seq */
3285         session = ceph_get_mds_session(di->lease_session);
3286         seq = di->lease_seq;
3287         __ceph_mdsc_drop_dentry_lease(dentry);
3288         spin_unlock(&dentry->d_lock);
3289
3290         dout("lease_release inode %p dentry %p to mds%d\n",
3291              inode, dentry, session->s_mds);
3292         ceph_mdsc_lease_send_msg(session, inode, dentry,
3293                                  CEPH_MDS_LEASE_RELEASE, seq);
3294         ceph_put_mds_session(session);
3295 }
3296
3297 /*
3298  * drop all leases (and dentry refs) in preparation for umount
3299  */
3300 static void drop_leases(struct ceph_mds_client *mdsc)
3301 {
3302         int i;
3303
3304         dout("drop_leases\n");
3305         mutex_lock(&mdsc->mutex);
3306         for (i = 0; i < mdsc->max_sessions; i++) {
3307                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3308                 if (!s)
3309                         continue;
3310                 mutex_unlock(&mdsc->mutex);
3311                 mutex_lock(&s->s_mutex);
3312                 mutex_unlock(&s->s_mutex);
3313                 ceph_put_mds_session(s);
3314                 mutex_lock(&mdsc->mutex);
3315         }
3316         mutex_unlock(&mdsc->mutex);
3317 }
3318
3319
3320
3321 /*
3322  * delayed work -- periodically trim expired leases, renew caps with mds
3323  */
3324 static void schedule_delayed(struct ceph_mds_client *mdsc)
3325 {
3326         int delay = 5;
3327         unsigned hz = round_jiffies_relative(HZ * delay);
3328         schedule_delayed_work(&mdsc->delayed_work, hz);
3329 }
3330
3331 static void delayed_work(struct work_struct *work)
3332 {
3333         int i;
3334         struct ceph_mds_client *mdsc =
3335                 container_of(work, struct ceph_mds_client, delayed_work.work);
3336         int renew_interval;
3337         int renew_caps;
3338
3339         dout("mdsc delayed_work\n");
3340         ceph_check_delayed_caps(mdsc);
3341
3342         mutex_lock(&mdsc->mutex);
3343         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3344         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3345                                    mdsc->last_renew_caps);
3346         if (renew_caps)
3347                 mdsc->last_renew_caps = jiffies;
3348
3349         for (i = 0; i < mdsc->max_sessions; i++) {
3350                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3351                 if (s == NULL)
3352                         continue;
3353                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3354                         dout("resending session close request for mds%d\n",
3355                              s->s_mds);
3356                         request_close_session(mdsc, s);
3357                         ceph_put_mds_session(s);
3358                         continue;
3359                 }
3360                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3361                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3362                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3363                                 pr_info("mds%d hung\n", s->s_mds);
3364                         }
3365                 }
3366                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3367                         /* this mds is failed or recovering, just wait */
3368                         ceph_put_mds_session(s);
3369                         continue;
3370                 }
3371                 mutex_unlock(&mdsc->mutex);
3372
3373                 mutex_lock(&s->s_mutex);
3374                 if (renew_caps)
3375                         send_renew_caps(mdsc, s);
3376                 else
3377                         ceph_con_keepalive(&s->s_con);
3378                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3379                     s->s_state == CEPH_MDS_SESSION_HUNG)
3380                         ceph_send_cap_releases(mdsc, s);
3381                 mutex_unlock(&s->s_mutex);
3382                 ceph_put_mds_session(s);
3383
3384                 mutex_lock(&mdsc->mutex);
3385         }
3386         mutex_unlock(&mdsc->mutex);
3387
3388         schedule_delayed(mdsc);
3389 }
3390
3391 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3392
3393 {
3394         struct ceph_mds_client *mdsc;
3395
3396         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3397         if (!mdsc)
3398                 return -ENOMEM;
3399         mdsc->fsc = fsc;
3400         fsc->mdsc = mdsc;
3401         mutex_init(&mdsc->mutex);
3402         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3403         if (mdsc->mdsmap == NULL) {
3404                 kfree(mdsc);
3405                 return -ENOMEM;
3406         }
3407
3408         init_completion(&mdsc->safe_umount_waiters);
3409         init_waitqueue_head(&mdsc->session_close_wq);
3410         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3411         mdsc->sessions = NULL;
3412         atomic_set(&mdsc->num_sessions, 0);
3413         mdsc->max_sessions = 0;
3414         mdsc->stopping = 0;
3415         mdsc->last_snap_seq = 0;
3416         init_rwsem(&mdsc->snap_rwsem);
3417         mdsc->snap_realms = RB_ROOT;
3418         INIT_LIST_HEAD(&mdsc->snap_empty);
3419         spin_lock_init(&mdsc->snap_empty_lock);
3420         mdsc->last_tid = 0;
3421         mdsc->oldest_tid = 0;
3422         mdsc->request_tree = RB_ROOT;
3423         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3424         mdsc->last_renew_caps = jiffies;
3425         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3426         spin_lock_init(&mdsc->cap_delay_lock);
3427         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3428         spin_lock_init(&mdsc->snap_flush_lock);
3429         mdsc->cap_flush_seq = 0;
3430         mdsc->last_cap_flush_tid = 1;
3431         INIT_LIST_HEAD(&mdsc->cap_dirty);
3432         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3433         mdsc->num_cap_flushing = 0;
3434         spin_lock_init(&mdsc->cap_dirty_lock);
3435         init_waitqueue_head(&mdsc->cap_flushing_wq);
3436         spin_lock_init(&mdsc->dentry_lru_lock);
3437         INIT_LIST_HEAD(&mdsc->dentry_lru);
3438
3439         ceph_caps_init(mdsc);
3440         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3441
3442         init_rwsem(&mdsc->pool_perm_rwsem);
3443         mdsc->pool_perm_tree = RB_ROOT;
3444
3445         return 0;
3446 }
3447
3448 /*
3449  * Wait for safe replies on open mds requests.  If we time out, drop
3450  * all requests from the tree to avoid dangling dentry refs.
3451  */
3452 static void wait_requests(struct ceph_mds_client *mdsc)
3453 {
3454         struct ceph_options *opts = mdsc->fsc->client->options;
3455         struct ceph_mds_request *req;
3456
3457         mutex_lock(&mdsc->mutex);
3458         if (__get_oldest_req(mdsc)) {
3459                 mutex_unlock(&mdsc->mutex);
3460
3461                 dout("wait_requests waiting for requests\n");
3462                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3463                                     ceph_timeout_jiffies(opts->mount_timeout));
3464
3465                 /* tear down remaining requests */
3466                 mutex_lock(&mdsc->mutex);
3467                 while ((req = __get_oldest_req(mdsc))) {
3468                         dout("wait_requests timed out on tid %llu\n",
3469                              req->r_tid);
3470                         __unregister_request(mdsc, req);
3471                 }
3472         }
3473         mutex_unlock(&mdsc->mutex);
3474         dout("wait_requests done\n");
3475 }
3476
3477 /*
3478  * called before mount is ro, and before dentries are torn down.
3479  * (hmm, does this still race with new lookups?)
3480  */
3481 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3482 {
3483         dout("pre_umount\n");
3484         mdsc->stopping = 1;
3485
3486         drop_leases(mdsc);
3487         ceph_flush_dirty_caps(mdsc);
3488         wait_requests(mdsc);
3489
3490         /*
3491          * wait for reply handlers to drop their request refs and
3492          * their inode/dcache refs
3493          */
3494         ceph_msgr_flush();
3495 }
3496
3497 /*
3498  * wait for all write mds requests to flush.
3499  */
3500 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3501 {
3502         struct ceph_mds_request *req = NULL, *nextreq;
3503         struct rb_node *n;
3504
3505         mutex_lock(&mdsc->mutex);
3506         dout("wait_unsafe_requests want %lld\n", want_tid);
3507 restart:
3508         req = __get_oldest_req(mdsc);
3509         while (req && req->r_tid <= want_tid) {
3510                 /* find next request */
3511                 n = rb_next(&req->r_node);
3512                 if (n)
3513                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3514                 else
3515                         nextreq = NULL;
3516                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
3517                     (req->r_op & CEPH_MDS_OP_WRITE)) {
3518                         /* write op */
3519                         ceph_mdsc_get_request(req);
3520                         if (nextreq)
3521                                 ceph_mdsc_get_request(nextreq);
3522                         mutex_unlock(&mdsc->mutex);
3523                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3524                              req->r_tid, want_tid);
3525                         wait_for_completion(&req->r_safe_completion);
3526                         mutex_lock(&mdsc->mutex);
3527                         ceph_mdsc_put_request(req);
3528                         if (!nextreq)
3529                                 break;  /* next dne before, so we're done! */
3530                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3531                                 /* next request was removed from tree */
3532                                 ceph_mdsc_put_request(nextreq);
3533                                 goto restart;
3534                         }
3535                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3536                 }
3537                 req = nextreq;
3538         }
3539         mutex_unlock(&mdsc->mutex);
3540         dout("wait_unsafe_requests done\n");
3541 }
3542
3543 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3544 {
3545         u64 want_tid, want_flush, want_snap;
3546
3547         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3548                 return;
3549
3550         dout("sync\n");
3551         mutex_lock(&mdsc->mutex);
3552         want_tid = mdsc->last_tid;
3553         mutex_unlock(&mdsc->mutex);
3554
3555         ceph_flush_dirty_caps(mdsc);
3556         spin_lock(&mdsc->cap_dirty_lock);
3557         want_flush = mdsc->cap_flush_seq;
3558         spin_unlock(&mdsc->cap_dirty_lock);
3559
3560         down_read(&mdsc->snap_rwsem);
3561         want_snap = mdsc->last_snap_seq;
3562         up_read(&mdsc->snap_rwsem);
3563
3564         dout("sync want tid %lld flush_seq %lld snap_seq %lld\n",
3565              want_tid, want_flush, want_snap);
3566
3567         wait_unsafe_requests(mdsc, want_tid);
3568         wait_caps_flush(mdsc, want_flush, want_snap);
3569 }
3570
3571 /*
3572  * true if all sessions are closed, or we force unmount
3573  */
3574 static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3575 {
3576         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3577                 return true;
3578         return atomic_read(&mdsc->num_sessions) == 0;
3579 }
3580
3581 /*
3582  * called after sb is ro.
3583  */
3584 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3585 {
3586         struct ceph_options *opts = mdsc->fsc->client->options;
3587         struct ceph_mds_session *session;
3588         int i;
3589
3590         dout("close_sessions\n");
3591
3592         /* close sessions */
3593         mutex_lock(&mdsc->mutex);
3594         for (i = 0; i < mdsc->max_sessions; i++) {
3595                 session = __ceph_lookup_mds_session(mdsc, i);
3596                 if (!session)
3597                         continue;
3598                 mutex_unlock(&mdsc->mutex);
3599                 mutex_lock(&session->s_mutex);
3600                 __close_session(mdsc, session);
3601                 mutex_unlock(&session->s_mutex);
3602                 ceph_put_mds_session(session);
3603                 mutex_lock(&mdsc->mutex);
3604         }
3605         mutex_unlock(&mdsc->mutex);
3606
3607         dout("waiting for sessions to close\n");
3608         wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3609                            ceph_timeout_jiffies(opts->mount_timeout));
3610
3611         /* tear down remaining sessions */
3612         mutex_lock(&mdsc->mutex);
3613         for (i = 0; i < mdsc->max_sessions; i++) {
3614                 if (mdsc->sessions[i]) {
3615                         session = get_session(mdsc->sessions[i]);
3616                         __unregister_session(mdsc, session);
3617                         mutex_unlock(&mdsc->mutex);
3618                         mutex_lock(&session->s_mutex);
3619                         remove_session_caps(session);
3620                         mutex_unlock(&session->s_mutex);
3621                         ceph_put_mds_session(session);
3622                         mutex_lock(&mdsc->mutex);
3623                 }
3624         }
3625         WARN_ON(!list_empty(&mdsc->cap_delay_list));
3626         mutex_unlock(&mdsc->mutex);
3627
3628         ceph_cleanup_empty_realms(mdsc);
3629
3630         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3631
3632         dout("stopped\n");
3633 }
3634
3635 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3636 {
3637         dout("stop\n");
3638         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3639         if (mdsc->mdsmap)
3640                 ceph_mdsmap_destroy(mdsc->mdsmap);
3641         kfree(mdsc->sessions);
3642         ceph_caps_finalize(mdsc);
3643         ceph_pool_perm_destroy(mdsc);
3644 }
3645
3646 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3647 {
3648         struct ceph_mds_client *mdsc = fsc->mdsc;
3649
3650         dout("mdsc_destroy %p\n", mdsc);
3651         ceph_mdsc_stop(mdsc);
3652
3653         /* flush out any connection work with references to us */
3654         ceph_msgr_flush();
3655
3656         fsc->mdsc = NULL;
3657         kfree(mdsc);
3658         dout("mdsc_destroy %p done\n", mdsc);
3659 }
3660
3661
3662 /*
3663  * handle mds map update.
3664  */
3665 void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3666 {
3667         u32 epoch;
3668         u32 maplen;
3669         void *p = msg->front.iov_base;
3670         void *end = p + msg->front.iov_len;
3671         struct ceph_mdsmap *newmap, *oldmap;
3672         struct ceph_fsid fsid;
3673         int err = -EINVAL;
3674
3675         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3676         ceph_decode_copy(&p, &fsid, sizeof(fsid));
3677         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3678                 return;
3679         epoch = ceph_decode_32(&p);
3680         maplen = ceph_decode_32(&p);
3681         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3682
3683         /* do we need it? */
3684         ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
3685         mutex_lock(&mdsc->mutex);
3686         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3687                 dout("handle_map epoch %u <= our %u\n",
3688                      epoch, mdsc->mdsmap->m_epoch);
3689                 mutex_unlock(&mdsc->mutex);
3690                 return;
3691         }
3692
3693         newmap = ceph_mdsmap_decode(&p, end);
3694         if (IS_ERR(newmap)) {
3695                 err = PTR_ERR(newmap);
3696                 goto bad_unlock;
3697         }
3698
3699         /* swap into place */
3700         if (mdsc->mdsmap) {
3701                 oldmap = mdsc->mdsmap;
3702                 mdsc->mdsmap = newmap;
3703                 check_new_map(mdsc, newmap, oldmap);
3704                 ceph_mdsmap_destroy(oldmap);
3705         } else {
3706                 mdsc->mdsmap = newmap;  /* first mds map */
3707         }
3708         mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3709
3710         __wake_requests(mdsc, &mdsc->waiting_for_map);
3711
3712         mutex_unlock(&mdsc->mutex);
3713         schedule_delayed(mdsc);
3714         return;
3715
3716 bad_unlock:
3717         mutex_unlock(&mdsc->mutex);
3718 bad:
3719         pr_err("error decoding mdsmap %d\n", err);
3720         return;
3721 }
3722
3723 static struct ceph_connection *con_get(struct ceph_connection *con)
3724 {
3725         struct ceph_mds_session *s = con->private;
3726
3727         if (get_session(s)) {
3728                 dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3729                 return con;
3730         }
3731         dout("mdsc con_get %p FAIL\n", s);
3732         return NULL;
3733 }
3734
3735 static void con_put(struct ceph_connection *con)
3736 {
3737         struct ceph_mds_session *s = con->private;
3738
3739         dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3740         ceph_put_mds_session(s);
3741 }
3742
3743 /*
3744  * if the client is unresponsive for long enough, the mds will kill
3745  * the session entirely.
3746  */
3747 static void peer_reset(struct ceph_connection *con)
3748 {
3749         struct ceph_mds_session *s = con->private;
3750         struct ceph_mds_client *mdsc = s->s_mdsc;
3751
3752         pr_warn("mds%d closed our session\n", s->s_mds);
3753         send_mds_reconnect(mdsc, s);
3754 }
3755
3756 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3757 {
3758         struct ceph_mds_session *s = con->private;
3759         struct ceph_mds_client *mdsc = s->s_mdsc;
3760         int type = le16_to_cpu(msg->hdr.type);
3761
3762         mutex_lock(&mdsc->mutex);
3763         if (__verify_registered_session(mdsc, s) < 0) {
3764                 mutex_unlock(&mdsc->mutex);
3765                 goto out;
3766         }
3767         mutex_unlock(&mdsc->mutex);
3768
3769         switch (type) {
3770         case CEPH_MSG_MDS_MAP:
3771                 ceph_mdsc_handle_map(mdsc, msg);
3772                 break;
3773         case CEPH_MSG_CLIENT_SESSION:
3774                 handle_session(s, msg);
3775                 break;
3776         case CEPH_MSG_CLIENT_REPLY:
3777                 handle_reply(s, msg);
3778                 break;
3779         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3780                 handle_forward(mdsc, s, msg);
3781                 break;
3782         case CEPH_MSG_CLIENT_CAPS:
3783                 ceph_handle_caps(s, msg);
3784                 break;
3785         case CEPH_MSG_CLIENT_SNAP:
3786                 ceph_handle_snap(mdsc, s, msg);
3787                 break;
3788         case CEPH_MSG_CLIENT_LEASE:
3789                 handle_lease(mdsc, s, msg);
3790                 break;
3791
3792         default:
3793                 pr_err("received unknown message type %d %s\n", type,
3794                        ceph_msg_type_name(type));
3795         }
3796 out:
3797         ceph_msg_put(msg);
3798 }
3799
3800 /*
3801  * authentication
3802  */
3803
3804 /*
3805  * Note: returned pointer is the address of a structure that's
3806  * managed separately.  Caller must *not* attempt to free it.
3807  */
3808 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3809                                         int *proto, int force_new)
3810 {
3811         struct ceph_mds_session *s = con->private;
3812         struct ceph_mds_client *mdsc = s->s_mdsc;
3813         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3814         struct ceph_auth_handshake *auth = &s->s_auth;
3815
3816         if (force_new && auth->authorizer) {
3817                 ceph_auth_destroy_authorizer(ac, auth->authorizer);
3818                 auth->authorizer = NULL;
3819         }
3820         if (!auth->authorizer) {
3821                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3822                                                       auth);
3823                 if (ret)
3824                         return ERR_PTR(ret);
3825         } else {
3826                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3827                                                       auth);
3828                 if (ret)
3829                         return ERR_PTR(ret);
3830         }
3831         *proto = ac->protocol;
3832
3833         return auth;
3834 }
3835
3836
3837 static int verify_authorizer_reply(struct ceph_connection *con, int len)
3838 {
3839         struct ceph_mds_session *s = con->private;
3840         struct ceph_mds_client *mdsc = s->s_mdsc;
3841         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3842
3843         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3844 }
3845
3846 static int invalidate_authorizer(struct ceph_connection *con)
3847 {
3848         struct ceph_mds_session *s = con->private;
3849         struct ceph_mds_client *mdsc = s->s_mdsc;
3850         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3851
3852         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3853
3854         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3855 }
3856
3857 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3858                                 struct ceph_msg_header *hdr, int *skip)
3859 {
3860         struct ceph_msg *msg;
3861         int type = (int) le16_to_cpu(hdr->type);
3862         int front_len = (int) le32_to_cpu(hdr->front_len);
3863
3864         if (con->in_msg)
3865                 return con->in_msg;
3866
3867         *skip = 0;
3868         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3869         if (!msg) {
3870                 pr_err("unable to allocate msg type %d len %d\n",
3871                        type, front_len);
3872                 return NULL;
3873         }
3874
3875         return msg;
3876 }
3877
3878 static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
3879 {
3880        struct ceph_mds_session *s = con->private;
3881        struct ceph_auth_handshake *auth = &s->s_auth;
3882        return ceph_auth_sign_message(auth, msg);
3883 }
3884
3885 static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
3886 {
3887        struct ceph_mds_session *s = con->private;
3888        struct ceph_auth_handshake *auth = &s->s_auth;
3889        return ceph_auth_check_message_signature(auth, msg);
3890 }
3891
3892 static const struct ceph_connection_operations mds_con_ops = {
3893         .get = con_get,
3894         .put = con_put,
3895         .dispatch = dispatch,
3896         .get_authorizer = get_authorizer,
3897         .verify_authorizer_reply = verify_authorizer_reply,
3898         .invalidate_authorizer = invalidate_authorizer,
3899         .peer_reset = peer_reset,
3900         .alloc_msg = mds_alloc_msg,
3901         .sign_message = sign_message,
3902         .check_message_signature = check_message_signature,
3903 };
3904
3905 /* eof */