fs/ceph/mds_client.c

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  45  * are no longer valid.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