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  44  * are no longer valid.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