kernel/fs/ceph/mds_client.c

   1 #include <linux/ceph/ceph_debug.h>
   2
   3 #include <linux/fs.h>
   4 #include <linux/wait.h>
   5 #include <linux/slab.h>
   6 #include <linux/gfp.h>
   7 #include <linux/sched.h>
   8 #include <linux/debugfs.h>
   9 #include <linux/seq_file.h>
  10 #include <linux/utsname.h>
  11
  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  44  * are no longer valid.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                         goto out;
1376                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1377                         goto out;
1378         }
1379         if ((used | wanted) & ~oissued & mine)
1380                 goto out;   /* we need these caps */
1381
1382         session->s_trim_caps--;
1383         if (oissued) {
1384                 /* we aren't the only cap.. just remove us */
1385                 __ceph_remove_cap(cap, true);
1386         } else {
1387                 /* try to drop referring dentries */
1388                 spin_unlock(&ci->i_ceph_lock);
1389                 d_prune_aliases(inode);
1390                 dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1391                      inode, cap, atomic_read(&inode->i_count));
1392                 return 0;
1393         }
1394
1395 out:
1396         spin_unlock(&ci->i_ceph_lock);
1397         return 0;
1398 }
1399
1400 /*
1401  * Trim session cap count down to some max number.
1402  */
1403 static int trim_caps(struct ceph_mds_client *mdsc,
1404                      struct ceph_mds_session *session,
1405                      int max_caps)
1406 {
1407         int trim_caps = session->s_nr_caps - max_caps;
1408
1409         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1410              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1411         if (trim_caps > 0) {
1412                 session->s_trim_caps = trim_caps;
1413                 iterate_session_caps(session, trim_caps_cb, session);
1414                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1415                      session->s_mds, session->s_nr_caps, max_caps,
1416                         trim_caps - session->s_trim_caps);
1417                 session->s_trim_caps = 0;
1418         }
1419
1420         ceph_add_cap_releases(mdsc, session);
1421         ceph_send_cap_releases(mdsc, session);
1422         return 0;
1423 }
1424
1425 /*
1426  * Allocate cap_release messages.  If there is a partially full message
1427  * in the queue, try to allocate enough to cover it's remainder, so that
1428  * we can send it immediately.
1429  *
1430  * Called under s_mutex.
1431  */
1432 int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
1433                           struct ceph_mds_session *session)
1434 {
1435         struct ceph_msg *msg, *partial = NULL;
1436         struct ceph_mds_cap_release *head;
1437         int err = -ENOMEM;
1438         int extra = mdsc->fsc->mount_options->cap_release_safety;
1439         int num;
1440
1441         dout("add_cap_releases %p mds%d extra %d\n", session, session->s_mds,
1442              extra);
1443
1444         spin_lock(&session->s_cap_lock);
1445
1446         if (!list_empty(&session->s_cap_releases)) {
1447                 msg = list_first_entry(&session->s_cap_releases,
1448                                        struct ceph_msg,
1449                                  list_head);
1450                 head = msg->front.iov_base;
1451                 num = le32_to_cpu(head->num);
1452                 if (num) {
1453                         dout(" partial %p with (%d/%d)\n", msg, num,
1454                              (int)CEPH_CAPS_PER_RELEASE);
1455                         extra += CEPH_CAPS_PER_RELEASE - num;
1456                         partial = msg;
1457                 }
1458         }
1459         while (session->s_num_cap_releases < session->s_nr_caps + extra) {
1460                 spin_unlock(&session->s_cap_lock);
1461                 msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE, PAGE_CACHE_SIZE,
1462                                    GFP_NOFS, false);
1463                 if (!msg)
1464                         goto out_unlocked;
1465                 dout("add_cap_releases %p msg %p now %d\n", session, msg,
1466                      (int)msg->front.iov_len);
1467                 head = msg->front.iov_base;
1468                 head->num = cpu_to_le32(0);
1469                 msg->front.iov_len = sizeof(*head);
1470                 spin_lock(&session->s_cap_lock);
1471                 list_add(&msg->list_head, &session->s_cap_releases);
1472                 session->s_num_cap_releases += CEPH_CAPS_PER_RELEASE;
1473         }
1474
1475         if (partial) {
1476                 head = partial->front.iov_base;
1477                 num = le32_to_cpu(head->num);
1478                 dout(" queueing partial %p with %d/%d\n", partial, num,
1479                      (int)CEPH_CAPS_PER_RELEASE);
1480                 list_move_tail(&partial->list_head,
1481                                &session->s_cap_releases_done);
1482                 session->s_num_cap_releases -= CEPH_CAPS_PER_RELEASE - num;
1483         }
1484         err = 0;
1485         spin_unlock(&session->s_cap_lock);
1486 out_unlocked:
1487         return err;
1488 }
1489
1490 static int check_cap_flush(struct inode *inode, u64 want_flush_seq)
1491 {
1492         struct ceph_inode_info *ci = ceph_inode(inode);
1493         int ret;
1494         spin_lock(&ci->i_ceph_lock);
1495         if (ci->i_flushing_caps)
1496                 ret = ci->i_cap_flush_seq >= want_flush_seq;
1497         else
1498                 ret = 1;
1499         spin_unlock(&ci->i_ceph_lock);
1500         return ret;
1501 }
1502
1503 /*
1504  * flush all dirty inode data to disk.
1505  *
1506  * returns true if we've flushed through want_flush_seq
1507  */
1508 static void wait_caps_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq)
1509 {
1510         int mds;
1511
1512         dout("check_cap_flush want %lld\n", want_flush_seq);
1513         mutex_lock(&mdsc->mutex);
1514         for (mds = 0; mds < mdsc->max_sessions; mds++) {
1515                 struct ceph_mds_session *session = mdsc->sessions[mds];
1516                 struct inode *inode = NULL;
1517
1518                 if (!session)
1519                         continue;
1520                 get_session(session);
1521                 mutex_unlock(&mdsc->mutex);
1522
1523                 mutex_lock(&session->s_mutex);
1524                 if (!list_empty(&session->s_cap_flushing)) {
1525                         struct ceph_inode_info *ci =
1526                                 list_entry(session->s_cap_flushing.next,
1527                                            struct ceph_inode_info,
1528                                            i_flushing_item);
1529
1530                         if (!check_cap_flush(&ci->vfs_inode, want_flush_seq)) {
1531                                 dout("check_cap_flush still flushing %p "
1532                                      "seq %lld <= %lld to mds%d\n",
1533                                      &ci->vfs_inode, ci->i_cap_flush_seq,
1534                                      want_flush_seq, session->s_mds);
1535                                 inode = igrab(&ci->vfs_inode);
1536                         }
1537                 }
1538                 mutex_unlock(&session->s_mutex);
1539                 ceph_put_mds_session(session);
1540
1541                 if (inode) {
1542                         wait_event(mdsc->cap_flushing_wq,
1543                                    check_cap_flush(inode, want_flush_seq));
1544                         iput(inode);
1545                 }
1546
1547                 mutex_lock(&mdsc->mutex);
1548         }
1549
1550         mutex_unlock(&mdsc->mutex);
1551         dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq);
1552 }
1553
1554 /*
1555  * called under s_mutex
1556  */
1557 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1558                             struct ceph_mds_session *session)
1559 {
1560         struct ceph_msg *msg;
1561
1562         dout("send_cap_releases mds%d\n", session->s_mds);
1563         spin_lock(&session->s_cap_lock);
1564         while (!list_empty(&session->s_cap_releases_done)) {
1565                 msg = list_first_entry(&session->s_cap_releases_done,
1566                                  struct ceph_msg, list_head);
1567                 list_del_init(&msg->list_head);
1568                 spin_unlock(&session->s_cap_lock);
1569                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1570                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1571                 ceph_con_send(&session->s_con, msg);
1572                 spin_lock(&session->s_cap_lock);
1573         }
1574         spin_unlock(&session->s_cap_lock);
1575 }
1576
1577 static void discard_cap_releases(struct ceph_mds_client *mdsc,
1578                                  struct ceph_mds_session *session)
1579 {
1580         struct ceph_msg *msg;
1581         struct ceph_mds_cap_release *head;
1582         unsigned num;
1583
1584         dout("discard_cap_releases mds%d\n", session->s_mds);
1585
1586         if (!list_empty(&session->s_cap_releases)) {
1587                 /* zero out the in-progress message */
1588                 msg = list_first_entry(&session->s_cap_releases,
1589                                         struct ceph_msg, list_head);
1590                 head = msg->front.iov_base;
1591                 num = le32_to_cpu(head->num);
1592                 dout("discard_cap_releases mds%d %p %u\n",
1593                      session->s_mds, msg, num);
1594                 head->num = cpu_to_le32(0);
1595                 msg->front.iov_len = sizeof(*head);
1596                 session->s_num_cap_releases += num;
1597         }
1598
1599         /* requeue completed messages */
1600         while (!list_empty(&session->s_cap_releases_done)) {
1601                 msg = list_first_entry(&session->s_cap_releases_done,
1602                                  struct ceph_msg, list_head);
1603                 list_del_init(&msg->list_head);
1604
1605                 head = msg->front.iov_base;
1606                 num = le32_to_cpu(head->num);
1607                 dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg,
1608                      num);
1609                 session->s_num_cap_releases += num;
1610                 head->num = cpu_to_le32(0);
1611                 msg->front.iov_len = sizeof(*head);
1612                 list_add(&msg->list_head, &session->s_cap_releases);
1613         }
1614 }
1615
1616 /*
1617  * requests
1618  */
1619
1620 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1621                                     struct inode *dir)
1622 {
1623         struct ceph_inode_info *ci = ceph_inode(dir);
1624         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1625         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1626         size_t size = sizeof(*rinfo->dir_in) + sizeof(*rinfo->dir_dname_len) +
1627                       sizeof(*rinfo->dir_dname) + sizeof(*rinfo->dir_dlease);
1628         int order, num_entries;
1629
1630         spin_lock(&ci->i_ceph_lock);
1631         num_entries = ci->i_files + ci->i_subdirs;
1632         spin_unlock(&ci->i_ceph_lock);
1633         num_entries = max(num_entries, 1);
1634         num_entries = min(num_entries, opt->max_readdir);
1635
1636         order = get_order(size * num_entries);
1637         while (order >= 0) {
1638                 rinfo->dir_in = (void*)__get_free_pages(GFP_NOFS | __GFP_NOWARN,
1639                                                         order);
1640                 if (rinfo->dir_in)
1641                         break;
1642                 order--;
1643         }
1644         if (!rinfo->dir_in)
1645                 return -ENOMEM;
1646
1647         num_entries = (PAGE_SIZE << order) / size;
1648         num_entries = min(num_entries, opt->max_readdir);
1649
1650         rinfo->dir_buf_size = PAGE_SIZE << order;
1651         req->r_num_caps = num_entries + 1;
1652         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1653         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1654         return 0;
1655 }
1656
1657 /*
1658  * Create an mds request.
1659  */
1660 struct ceph_mds_request *
1661 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1662 {
1663         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1664
1665         if (!req)
1666                 return ERR_PTR(-ENOMEM);
1667
1668         mutex_init(&req->r_fill_mutex);
1669         req->r_mdsc = mdsc;
1670         req->r_started = jiffies;
1671         req->r_resend_mds = -1;
1672         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1673         req->r_fmode = -1;
1674         kref_init(&req->r_kref);
1675         INIT_LIST_HEAD(&req->r_wait);
1676         init_completion(&req->r_completion);
1677         init_completion(&req->r_safe_completion);
1678         INIT_LIST_HEAD(&req->r_unsafe_item);
1679
1680         req->r_stamp = CURRENT_TIME;
1681
1682         req->r_op = op;
1683         req->r_direct_mode = mode;
1684         return req;
1685 }
1686
1687 /*
1688  * return oldest (lowest) request, tid in request tree, 0 if none.
1689  *
1690  * called under mdsc->mutex.
1691  */
1692 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1693 {
1694         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1695                 return NULL;
1696         return rb_entry(rb_first(&mdsc->request_tree),
1697                         struct ceph_mds_request, r_node);
1698 }
1699
1700 static u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1701 {
1702         struct ceph_mds_request *req = __get_oldest_req(mdsc);
1703
1704         if (req)
1705                 return req->r_tid;
1706         return 0;
1707 }
1708
1709 /*
1710  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1711  * on build_path_from_dentry in fs/cifs/dir.c.
1712  *
1713  * If @stop_on_nosnap, generate path relative to the first non-snapped
1714  * inode.
1715  *
1716  * Encode hidden .snap dirs as a double /, i.e.
1717  *   foo/.snap/bar -> foo//bar
1718  */
1719 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1720                            int stop_on_nosnap)
1721 {
1722         struct dentry *temp;
1723         char *path;
1724         int len, pos;
1725         unsigned seq;
1726
1727         if (dentry == NULL)
1728                 return ERR_PTR(-EINVAL);
1729
1730 retry:
1731         len = 0;
1732         seq = read_seqbegin(&rename_lock);
1733         rcu_read_lock();
1734         for (temp = dentry; !IS_ROOT(temp);) {
1735                 struct inode *inode = d_inode(temp);
1736                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1737                         len++;  /* slash only */
1738                 else if (stop_on_nosnap && inode &&
1739                          ceph_snap(inode) == CEPH_NOSNAP)
1740                         break;
1741                 else
1742                         len += 1 + temp->d_name.len;
1743                 temp = temp->d_parent;
1744         }
1745         rcu_read_unlock();
1746         if (len)
1747                 len--;  /* no leading '/' */
1748
1749         path = kmalloc(len+1, GFP_NOFS);
1750         if (path == NULL)
1751                 return ERR_PTR(-ENOMEM);
1752         pos = len;
1753         path[pos] = 0;  /* trailing null */
1754         rcu_read_lock();
1755         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1756                 struct inode *inode;
1757
1758                 spin_lock(&temp->d_lock);
1759                 inode = d_inode(temp);
1760                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1761                         dout("build_path path+%d: %p SNAPDIR\n",
1762                              pos, temp);
1763                 } else if (stop_on_nosnap && inode &&
1764                            ceph_snap(inode) == CEPH_NOSNAP) {
1765                         spin_unlock(&temp->d_lock);
1766                         break;
1767                 } else {
1768                         pos -= temp->d_name.len;
1769                         if (pos < 0) {
1770                                 spin_unlock(&temp->d_lock);
1771                                 break;
1772                         }
1773                         strncpy(path + pos, temp->d_name.name,
1774                                 temp->d_name.len);
1775                 }
1776                 spin_unlock(&temp->d_lock);
1777                 if (pos)
1778                         path[--pos] = '/';
1779                 temp = temp->d_parent;
1780         }
1781         rcu_read_unlock();
1782         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1783                 pr_err("build_path did not end path lookup where "
1784                        "expected, namelen is %d, pos is %d\n", len, pos);
1785                 /* presumably this is only possible if racing with a
1786                    rename of one of the parent directories (we can not
1787                    lock the dentries above us to prevent this, but
1788                    retrying should be harmless) */
1789                 kfree(path);
1790                 goto retry;
1791         }
1792
1793         *base = ceph_ino(d_inode(temp));
1794         *plen = len;
1795         dout("build_path on %p %d built %llx '%.*s'\n",
1796              dentry, d_count(dentry), *base, len, path);
1797         return path;
1798 }
1799
1800 static int build_dentry_path(struct dentry *dentry,
1801                              const char **ppath, int *ppathlen, u64 *pino,
1802                              int *pfreepath)
1803 {
1804         char *path;
1805
1806         if (ceph_snap(d_inode(dentry->d_parent)) == CEPH_NOSNAP) {
1807                 *pino = ceph_ino(d_inode(dentry->d_parent));
1808                 *ppath = dentry->d_name.name;
1809                 *ppathlen = dentry->d_name.len;
1810                 return 0;
1811         }
1812         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1813         if (IS_ERR(path))
1814                 return PTR_ERR(path);
1815         *ppath = path;
1816         *pfreepath = 1;
1817         return 0;
1818 }
1819
1820 static int build_inode_path(struct inode *inode,
1821                             const char **ppath, int *ppathlen, u64 *pino,
1822                             int *pfreepath)
1823 {
1824         struct dentry *dentry;
1825         char *path;
1826
1827         if (ceph_snap(inode) == CEPH_NOSNAP) {
1828                 *pino = ceph_ino(inode);
1829                 *ppathlen = 0;
1830                 return 0;
1831         }
1832         dentry = d_find_alias(inode);
1833         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1834         dput(dentry);
1835         if (IS_ERR(path))
1836                 return PTR_ERR(path);
1837         *ppath = path;
1838         *pfreepath = 1;
1839         return 0;
1840 }
1841
1842 /*
1843  * request arguments may be specified via an inode *, a dentry *, or
1844  * an explicit ino+path.
1845  */
1846 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1847                                   const char *rpath, u64 rino,
1848                                   const char **ppath, int *pathlen,
1849                                   u64 *ino, int *freepath)
1850 {
1851         int r = 0;
1852
1853         if (rinode) {
1854                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1855                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1856                      ceph_snap(rinode));
1857         } else if (rdentry) {
1858                 r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1859                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1860                      *ppath);
1861         } else if (rpath || rino) {
1862                 *ino = rino;
1863                 *ppath = rpath;
1864                 *pathlen = rpath ? strlen(rpath) : 0;
1865                 dout(" path %.*s\n", *pathlen, rpath);
1866         }
1867
1868         return r;
1869 }
1870
1871 /*
1872  * called under mdsc->mutex
1873  */
1874 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1875                                                struct ceph_mds_request *req,
1876                                                int mds, bool drop_cap_releases)
1877 {
1878         struct ceph_msg *msg;
1879         struct ceph_mds_request_head *head;
1880         const char *path1 = NULL;
1881         const char *path2 = NULL;
1882         u64 ino1 = 0, ino2 = 0;
1883         int pathlen1 = 0, pathlen2 = 0;
1884         int freepath1 = 0, freepath2 = 0;
1885         int len;
1886         u16 releases;
1887         void *p, *end;
1888         int ret;
1889
1890         ret = set_request_path_attr(req->r_inode, req->r_dentry,
1891                               req->r_path1, req->r_ino1.ino,
1892                               &path1, &pathlen1, &ino1, &freepath1);
1893         if (ret < 0) {
1894                 msg = ERR_PTR(ret);
1895                 goto out;
1896         }
1897
1898         ret = set_request_path_attr(NULL, req->r_old_dentry,
1899                               req->r_path2, req->r_ino2.ino,
1900                               &path2, &pathlen2, &ino2, &freepath2);
1901         if (ret < 0) {
1902                 msg = ERR_PTR(ret);
1903                 goto out_free1;
1904         }
1905
1906         len = sizeof(*head) +
1907                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
1908                 sizeof(struct timespec);
1909
1910         /* calculate (max) length for cap releases */
1911         len += sizeof(struct ceph_mds_request_release) *
1912                 (!!req->r_inode_drop + !!req->r_dentry_drop +
1913                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1914         if (req->r_dentry_drop)
1915                 len += req->r_dentry->d_name.len;
1916         if (req->r_old_dentry_drop)
1917                 len += req->r_old_dentry->d_name.len;
1918
1919         msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1920         if (!msg) {
1921                 msg = ERR_PTR(-ENOMEM);
1922                 goto out_free2;
1923         }
1924
1925         msg->hdr.version = cpu_to_le16(2);
1926         msg->hdr.tid = cpu_to_le64(req->r_tid);
1927
1928         head = msg->front.iov_base;
1929         p = msg->front.iov_base + sizeof(*head);
1930         end = msg->front.iov_base + msg->front.iov_len;
1931
1932         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1933         head->op = cpu_to_le32(req->r_op);
1934         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1935         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1936         head->args = req->r_args;
1937
1938         ceph_encode_filepath(&p, end, ino1, path1);
1939         ceph_encode_filepath(&p, end, ino2, path2);
1940
1941         /* make note of release offset, in case we need to replay */
1942         req->r_request_release_offset = p - msg->front.iov_base;
1943
1944         /* cap releases */
1945         releases = 0;
1946         if (req->r_inode_drop)
1947                 releases += ceph_encode_inode_release(&p,
1948                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
1949                       mds, req->r_inode_drop, req->r_inode_unless, 0);
1950         if (req->r_dentry_drop)
1951                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
1952                        mds, req->r_dentry_drop, req->r_dentry_unless);
1953         if (req->r_old_dentry_drop)
1954                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1955                        mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1956         if (req->r_old_inode_drop)
1957                 releases += ceph_encode_inode_release(&p,
1958                       d_inode(req->r_old_dentry),
1959                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1960
1961         if (drop_cap_releases) {
1962                 releases = 0;
1963                 p = msg->front.iov_base + req->r_request_release_offset;
1964         }
1965
1966         head->num_releases = cpu_to_le16(releases);
1967
1968         /* time stamp */
1969         {
1970                 struct ceph_timespec ts;
1971                 ceph_encode_timespec(&ts, &req->r_stamp);
1972                 ceph_encode_copy(&p, &ts, sizeof(ts));
1973         }
1974
1975         BUG_ON(p > end);
1976         msg->front.iov_len = p - msg->front.iov_base;
1977         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1978
1979         if (req->r_pagelist) {
1980                 struct ceph_pagelist *pagelist = req->r_pagelist;
1981                 atomic_inc(&pagelist->refcnt);
1982                 ceph_msg_data_add_pagelist(msg, pagelist);
1983                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
1984         } else {
1985                 msg->hdr.data_len = 0;
1986         }
1987
1988         msg->hdr.data_off = cpu_to_le16(0);
1989
1990 out_free2:
1991         if (freepath2)
1992                 kfree((char *)path2);
1993 out_free1:
1994         if (freepath1)
1995                 kfree((char *)path1);
1996 out:
1997         return msg;
1998 }
1999
2000 /*
2001  * called under mdsc->mutex if error, under no mutex if
2002  * success.
2003  */
2004 static void complete_request(struct ceph_mds_client *mdsc,
2005                              struct ceph_mds_request *req)
2006 {
2007         if (req->r_callback)
2008                 req->r_callback(mdsc, req);
2009         else
2010                 complete_all(&req->r_completion);
2011 }
2012
2013 /*
2014  * called under mdsc->mutex
2015  */
2016 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2017                                   struct ceph_mds_request *req,
2018                                   int mds, bool drop_cap_releases)
2019 {
2020         struct ceph_mds_request_head *rhead;
2021         struct ceph_msg *msg;
2022         int flags = 0;
2023
2024         req->r_attempts++;
2025         if (req->r_inode) {
2026                 struct ceph_cap *cap =
2027                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2028
2029                 if (cap)
2030                         req->r_sent_on_mseq = cap->mseq;
2031                 else
2032                         req->r_sent_on_mseq = -1;
2033         }
2034         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2035              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2036
2037         if (req->r_got_unsafe) {
2038                 void *p;
2039                 /*
2040                  * Replay.  Do not regenerate message (and rebuild
2041                  * paths, etc.); just use the original message.
2042                  * Rebuilding paths will break for renames because
2043                  * d_move mangles the src name.
2044                  */
2045                 msg = req->r_request;
2046                 rhead = msg->front.iov_base;
2047
2048                 flags = le32_to_cpu(rhead->flags);
2049                 flags |= CEPH_MDS_FLAG_REPLAY;
2050                 rhead->flags = cpu_to_le32(flags);
2051
2052                 if (req->r_target_inode)
2053                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2054
2055                 rhead->num_retry = req->r_attempts - 1;
2056
2057                 /* remove cap/dentry releases from message */
2058                 rhead->num_releases = 0;
2059
2060                 /* time stamp */
2061                 p = msg->front.iov_base + req->r_request_release_offset;
2062                 {
2063                         struct ceph_timespec ts;
2064                         ceph_encode_timespec(&ts, &req->r_stamp);
2065                         ceph_encode_copy(&p, &ts, sizeof(ts));
2066                 }
2067
2068                 msg->front.iov_len = p - msg->front.iov_base;
2069                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2070                 return 0;
2071         }
2072
2073         if (req->r_request) {
2074                 ceph_msg_put(req->r_request);
2075                 req->r_request = NULL;
2076         }
2077         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2078         if (IS_ERR(msg)) {
2079                 req->r_err = PTR_ERR(msg);
2080                 complete_request(mdsc, req);
2081                 return PTR_ERR(msg);
2082         }
2083         req->r_request = msg;
2084
2085         rhead = msg->front.iov_base;
2086         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2087         if (req->r_got_unsafe)
2088                 flags |= CEPH_MDS_FLAG_REPLAY;
2089         if (req->r_locked_dir)
2090                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2091         rhead->flags = cpu_to_le32(flags);
2092         rhead->num_fwd = req->r_num_fwd;
2093         rhead->num_retry = req->r_attempts - 1;
2094         rhead->ino = 0;
2095
2096         dout(" r_locked_dir = %p\n", req->r_locked_dir);
2097         return 0;
2098 }
2099
2100 /*
2101  * send request, or put it on the appropriate wait list.
2102  */
2103 static int __do_request(struct ceph_mds_client *mdsc,
2104                         struct ceph_mds_request *req)
2105 {
2106         struct ceph_mds_session *session = NULL;
2107         int mds = -1;
2108         int err = -EAGAIN;
2109
2110         if (req->r_err || req->r_got_result) {
2111                 if (req->r_aborted)
2112                         __unregister_request(mdsc, req);
2113                 goto out;
2114         }
2115
2116         if (req->r_timeout &&
2117             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2118                 dout("do_request timed out\n");
2119                 err = -EIO;
2120                 goto finish;
2121         }
2122
2123         put_request_session(req);
2124
2125         mds = __choose_mds(mdsc, req);
2126         if (mds < 0 ||
2127             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2128                 dout("do_request no mds or not active, waiting for map\n");
2129                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2130                 goto out;
2131         }
2132
2133         /* get, open session */
2134         session = __ceph_lookup_mds_session(mdsc, mds);
2135         if (!session) {
2136                 session = register_session(mdsc, mds);
2137                 if (IS_ERR(session)) {
2138                         err = PTR_ERR(session);
2139                         goto finish;
2140                 }
2141         }
2142         req->r_session = get_session(session);
2143
2144         dout("do_request mds%d session %p state %s\n", mds, session,
2145              ceph_session_state_name(session->s_state));
2146         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2147             session->s_state != CEPH_MDS_SESSION_HUNG) {
2148                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2149                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2150                         __open_session(mdsc, session);
2151                 list_add(&req->r_wait, &session->s_waiting);
2152                 goto out_session;
2153         }
2154
2155         /* send request */
2156         req->r_resend_mds = -1;   /* forget any previous mds hint */
2157
2158         if (req->r_request_started == 0)   /* note request start time */
2159                 req->r_request_started = jiffies;
2160
2161         err = __prepare_send_request(mdsc, req, mds, false);
2162         if (!err) {
2163                 ceph_msg_get(req->r_request);
2164                 ceph_con_send(&session->s_con, req->r_request);
2165         }
2166
2167 out_session:
2168         ceph_put_mds_session(session);
2169 out:
2170         return err;
2171
2172 finish:
2173         req->r_err = err;
2174         complete_request(mdsc, req);
2175         goto out;
2176 }
2177
2178 /*
2179  * called under mdsc->mutex
2180  */
2181 static void __wake_requests(struct ceph_mds_client *mdsc,
2182                             struct list_head *head)
2183 {
2184         struct ceph_mds_request *req;
2185         LIST_HEAD(tmp_list);
2186
2187         list_splice_init(head, &tmp_list);
2188
2189         while (!list_empty(&tmp_list)) {
2190                 req = list_entry(tmp_list.next,
2191                                  struct ceph_mds_request, r_wait);
2192                 list_del_init(&req->r_wait);
2193                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2194                 __do_request(mdsc, req);
2195         }
2196 }
2197
2198 /*
2199  * Wake up threads with requests pending for @mds, so that they can
2200  * resubmit their requests to a possibly different mds.
2201  */
2202 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2203 {
2204         struct ceph_mds_request *req;
2205         struct rb_node *p = rb_first(&mdsc->request_tree);
2206
2207         dout("kick_requests mds%d\n", mds);
2208         while (p) {
2209                 req = rb_entry(p, struct ceph_mds_request, r_node);
2210                 p = rb_next(p);
2211                 if (req->r_got_unsafe)
2212                         continue;
2213                 if (req->r_attempts > 0)
2214                         continue; /* only new requests */
2215                 if (req->r_session &&
2216                     req->r_session->s_mds == mds) {
2217                         dout(" kicking tid %llu\n", req->r_tid);
2218                         list_del_init(&req->r_wait);
2219                         __do_request(mdsc, req);
2220                 }
2221         }
2222 }
2223
2224 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2225                               struct ceph_mds_request *req)
2226 {
2227         dout("submit_request on %p\n", req);
2228         mutex_lock(&mdsc->mutex);
2229         __register_request(mdsc, req, NULL);
2230         __do_request(mdsc, req);
2231         mutex_unlock(&mdsc->mutex);
2232 }
2233
2234 /*
2235  * Synchrously perform an mds request.  Take care of all of the
2236  * session setup, forwarding, retry details.
2237  */
2238 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2239                          struct inode *dir,
2240                          struct ceph_mds_request *req)
2241 {
2242         int err;
2243
2244         dout("do_request on %p\n", req);
2245
2246         /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2247         if (req->r_inode)
2248                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2249         if (req->r_locked_dir)
2250                 ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2251         if (req->r_old_dentry_dir)
2252                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2253                                   CEPH_CAP_PIN);
2254
2255         /* issue */
2256         mutex_lock(&mdsc->mutex);
2257         __register_request(mdsc, req, dir);
2258         __do_request(mdsc, req);
2259
2260         if (req->r_err) {
2261                 err = req->r_err;
2262                 __unregister_request(mdsc, req);
2263                 dout("do_request early error %d\n", err);
2264                 goto out;
2265         }
2266
2267         /* wait */
2268         mutex_unlock(&mdsc->mutex);
2269         dout("do_request waiting\n");
2270         if (req->r_timeout) {
2271                 err = (long)wait_for_completion_killable_timeout(
2272                         &req->r_completion, req->r_timeout);
2273                 if (err == 0)
2274                         err = -EIO;
2275         } else if (req->r_wait_for_completion) {
2276                 err = req->r_wait_for_completion(mdsc, req);
2277         } else {
2278                 err = wait_for_completion_killable(&req->r_completion);
2279         }
2280         dout("do_request waited, got %d\n", err);
2281         mutex_lock(&mdsc->mutex);
2282
2283         /* only abort if we didn't race with a real reply */
2284         if (req->r_got_result) {
2285                 err = le32_to_cpu(req->r_reply_info.head->result);
2286         } else if (err < 0) {
2287                 dout("aborted request %lld with %d\n", req->r_tid, err);
2288
2289                 /*
2290                  * ensure we aren't running concurrently with
2291                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2292                  * rely on locks (dir mutex) held by our caller.
2293                  */
2294                 mutex_lock(&req->r_fill_mutex);
2295                 req->r_err = err;
2296                 req->r_aborted = true;
2297                 mutex_unlock(&req->r_fill_mutex);
2298
2299                 if (req->r_locked_dir &&
2300                     (req->r_op & CEPH_MDS_OP_WRITE))
2301                         ceph_invalidate_dir_request(req);
2302         } else {
2303                 err = req->r_err;
2304         }
2305
2306 out:
2307         mutex_unlock(&mdsc->mutex);
2308         dout("do_request %p done, result %d\n", req, err);
2309         return err;
2310 }
2311
2312 /*
2313  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2314  * namespace request.
2315  */
2316 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2317 {
2318         struct inode *inode = req->r_locked_dir;
2319
2320         dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2321
2322         ceph_dir_clear_complete(inode);
2323         if (req->r_dentry)
2324                 ceph_invalidate_dentry_lease(req->r_dentry);
2325         if (req->r_old_dentry)
2326                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2327 }
2328
2329 /*
2330  * Handle mds reply.
2331  *
2332  * We take the session mutex and parse and process the reply immediately.
2333  * This preserves the logical ordering of replies, capabilities, etc., sent
2334  * by the MDS as they are applied to our local cache.
2335  */
2336 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2337 {
2338         struct ceph_mds_client *mdsc = session->s_mdsc;
2339         struct ceph_mds_request *req;
2340         struct ceph_mds_reply_head *head = msg->front.iov_base;
2341         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2342         struct ceph_snap_realm *realm;
2343         u64 tid;
2344         int err, result;
2345         int mds = session->s_mds;
2346
2347         if (msg->front.iov_len < sizeof(*head)) {
2348                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2349                 ceph_msg_dump(msg);
2350                 return;
2351         }
2352
2353         /* get request, session */
2354         tid = le64_to_cpu(msg->hdr.tid);
2355         mutex_lock(&mdsc->mutex);
2356         req = __lookup_request(mdsc, tid);
2357         if (!req) {
2358                 dout("handle_reply on unknown tid %llu\n", tid);
2359                 mutex_unlock(&mdsc->mutex);
2360                 return;
2361         }
2362         dout("handle_reply %p\n", req);
2363
2364         /* correct session? */
2365         if (req->r_session != session) {
2366                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2367                        " not mds%d\n", tid, session->s_mds,
2368                        req->r_session ? req->r_session->s_mds : -1);
2369                 mutex_unlock(&mdsc->mutex);
2370                 goto out;
2371         }
2372
2373         /* dup? */
2374         if ((req->r_got_unsafe && !head->safe) ||
2375             (req->r_got_safe && head->safe)) {
2376                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2377                            head->safe ? "safe" : "unsafe", tid, mds);
2378                 mutex_unlock(&mdsc->mutex);
2379                 goto out;
2380         }
2381         if (req->r_got_safe && !head->safe) {
2382                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2383                            tid, mds);
2384                 mutex_unlock(&mdsc->mutex);
2385                 goto out;
2386         }
2387
2388         result = le32_to_cpu(head->result);
2389
2390         /*
2391          * Handle an ESTALE
2392          * if we're not talking to the authority, send to them
2393          * if the authority has changed while we weren't looking,
2394          * send to new authority
2395          * Otherwise we just have to return an ESTALE
2396          */
2397         if (result == -ESTALE) {
2398                 dout("got ESTALE on request %llu", req->r_tid);
2399                 req->r_resend_mds = -1;
2400                 if (req->r_direct_mode != USE_AUTH_MDS) {
2401                         dout("not using auth, setting for that now");
2402                         req->r_direct_mode = USE_AUTH_MDS;
2403                         __do_request(mdsc, req);
2404                         mutex_unlock(&mdsc->mutex);
2405                         goto out;
2406                 } else  {
2407                         int mds = __choose_mds(mdsc, req);
2408                         if (mds >= 0 && mds != req->r_session->s_mds) {
2409                                 dout("but auth changed, so resending");
2410                                 __do_request(mdsc, req);
2411                                 mutex_unlock(&mdsc->mutex);
2412                                 goto out;
2413                         }
2414                 }
2415                 dout("have to return ESTALE on request %llu", req->r_tid);
2416         }
2417
2418
2419         if (head->safe) {
2420                 req->r_got_safe = true;
2421                 __unregister_request(mdsc, req);
2422
2423                 if (req->r_got_unsafe) {
2424                         /*
2425                          * We already handled the unsafe response, now do the
2426                          * cleanup.  No need to examine the response; the MDS
2427                          * doesn't include any result info in the safe
2428                          * response.  And even if it did, there is nothing
2429                          * useful we could do with a revised return value.
2430                          */
2431                         dout("got safe reply %llu, mds%d\n", tid, mds);
2432                         list_del_init(&req->r_unsafe_item);
2433
2434                         /* last unsafe request during umount? */
2435                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2436                                 complete_all(&mdsc->safe_umount_waiters);
2437                         mutex_unlock(&mdsc->mutex);
2438                         goto out;
2439                 }
2440         } else {
2441                 req->r_got_unsafe = true;
2442                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2443         }
2444
2445         dout("handle_reply tid %lld result %d\n", tid, result);
2446         rinfo = &req->r_reply_info;
2447         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2448         mutex_unlock(&mdsc->mutex);
2449
2450         mutex_lock(&session->s_mutex);
2451         if (err < 0) {
2452                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2453                 ceph_msg_dump(msg);
2454                 goto out_err;
2455         }
2456
2457         /* snap trace */
2458         realm = NULL;
2459         if (rinfo->snapblob_len) {
2460                 down_write(&mdsc->snap_rwsem);
2461                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2462                                 rinfo->snapblob + rinfo->snapblob_len,
2463                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2464                                 &realm);
2465                 downgrade_write(&mdsc->snap_rwsem);
2466         } else {
2467                 down_read(&mdsc->snap_rwsem);
2468         }
2469
2470         /* insert trace into our cache */
2471         mutex_lock(&req->r_fill_mutex);
2472         err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2473         if (err == 0) {
2474                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2475                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2476                         ceph_readdir_prepopulate(req, req->r_session);
2477                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2478         }
2479         mutex_unlock(&req->r_fill_mutex);
2480
2481         up_read(&mdsc->snap_rwsem);
2482         if (realm)
2483                 ceph_put_snap_realm(mdsc, realm);
2484 out_err:
2485         mutex_lock(&mdsc->mutex);
2486         if (!req->r_aborted) {
2487                 if (err) {
2488                         req->r_err = err;
2489                 } else {
2490                         req->r_reply = msg;
2491                         ceph_msg_get(msg);
2492                         req->r_got_result = true;
2493                 }
2494         } else {
2495                 dout("reply arrived after request %lld was aborted\n", tid);
2496         }
2497         mutex_unlock(&mdsc->mutex);
2498
2499         ceph_add_cap_releases(mdsc, req->r_session);
2500         mutex_unlock(&session->s_mutex);
2501
2502         /* kick calling process */
2503         complete_request(mdsc, req);
2504 out:
2505         ceph_mdsc_put_request(req);
2506         return;
2507 }
2508
2509
2510
2511 /*
2512  * handle mds notification that our request has been forwarded.
2513  */
2514 static void handle_forward(struct ceph_mds_client *mdsc,
2515                            struct ceph_mds_session *session,
2516                            struct ceph_msg *msg)
2517 {
2518         struct ceph_mds_request *req;
2519         u64 tid = le64_to_cpu(msg->hdr.tid);
2520         u32 next_mds;
2521         u32 fwd_seq;
2522         int err = -EINVAL;
2523         void *p = msg->front.iov_base;
2524         void *end = p + msg->front.iov_len;
2525
2526         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2527         next_mds = ceph_decode_32(&p);
2528         fwd_seq = ceph_decode_32(&p);
2529
2530         mutex_lock(&mdsc->mutex);
2531         req = __lookup_request(mdsc, tid);
2532         if (!req) {
2533                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2534                 goto out;  /* dup reply? */
2535         }
2536
2537         if (req->r_aborted) {
2538                 dout("forward tid %llu aborted, unregistering\n", tid);
2539                 __unregister_request(mdsc, req);
2540         } else if (fwd_seq <= req->r_num_fwd) {
2541                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2542                      tid, next_mds, req->r_num_fwd, fwd_seq);
2543         } else {
2544                 /* resend. forward race not possible; mds would drop */
2545                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2546                 BUG_ON(req->r_err);
2547                 BUG_ON(req->r_got_result);
2548                 req->r_attempts = 0;
2549                 req->r_num_fwd = fwd_seq;
2550                 req->r_resend_mds = next_mds;
2551                 put_request_session(req);
2552                 __do_request(mdsc, req);
2553         }
2554         ceph_mdsc_put_request(req);
2555 out:
2556         mutex_unlock(&mdsc->mutex);
2557         return;
2558
2559 bad:
2560         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2561 }
2562
2563 /*
2564  * handle a mds session control message
2565  */
2566 static void handle_session(struct ceph_mds_session *session,
2567                            struct ceph_msg *msg)
2568 {
2569         struct ceph_mds_client *mdsc = session->s_mdsc;
2570         u32 op;
2571         u64 seq;
2572         int mds = session->s_mds;
2573         struct ceph_mds_session_head *h = msg->front.iov_base;
2574         int wake = 0;
2575
2576         /* decode */
2577         if (msg->front.iov_len != sizeof(*h))
2578                 goto bad;
2579         op = le32_to_cpu(h->op);
2580         seq = le64_to_cpu(h->seq);
2581
2582         mutex_lock(&mdsc->mutex);
2583         if (op == CEPH_SESSION_CLOSE)
2584                 __unregister_session(mdsc, session);
2585         /* FIXME: this ttl calculation is generous */
2586         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2587         mutex_unlock(&mdsc->mutex);
2588
2589         mutex_lock(&session->s_mutex);
2590
2591         dout("handle_session mds%d %s %p state %s seq %llu\n",
2592              mds, ceph_session_op_name(op), session,
2593              ceph_session_state_name(session->s_state), seq);
2594
2595         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2596                 session->s_state = CEPH_MDS_SESSION_OPEN;
2597                 pr_info("mds%d came back\n", session->s_mds);
2598         }
2599
2600         switch (op) {
2601         case CEPH_SESSION_OPEN:
2602                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2603                         pr_info("mds%d reconnect success\n", session->s_mds);
2604                 session->s_state = CEPH_MDS_SESSION_OPEN;
2605                 renewed_caps(mdsc, session, 0);
2606                 wake = 1;
2607                 if (mdsc->stopping)
2608                         __close_session(mdsc, session);
2609                 break;
2610
2611         case CEPH_SESSION_RENEWCAPS:
2612                 if (session->s_renew_seq == seq)
2613                         renewed_caps(mdsc, session, 1);
2614                 break;
2615
2616         case CEPH_SESSION_CLOSE:
2617                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2618                         pr_info("mds%d reconnect denied\n", session->s_mds);
2619                 cleanup_session_requests(mdsc, session);
2620                 remove_session_caps(session);
2621                 wake = 2; /* for good measure */
2622                 wake_up_all(&mdsc->session_close_wq);
2623                 break;
2624
2625         case CEPH_SESSION_STALE:
2626                 pr_info("mds%d caps went stale, renewing\n",
2627                         session->s_mds);
2628                 spin_lock(&session->s_gen_ttl_lock);
2629                 session->s_cap_gen++;
2630                 session->s_cap_ttl = jiffies - 1;
2631                 spin_unlock(&session->s_gen_ttl_lock);
2632                 send_renew_caps(mdsc, session);
2633                 break;
2634
2635         case CEPH_SESSION_RECALL_STATE:
2636                 trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2637                 break;
2638
2639         case CEPH_SESSION_FLUSHMSG:
2640                 send_flushmsg_ack(mdsc, session, seq);
2641                 break;
2642
2643         case CEPH_SESSION_FORCE_RO:
2644                 dout("force_session_readonly %p\n", session);
2645                 spin_lock(&session->s_cap_lock);
2646                 session->s_readonly = true;
2647                 spin_unlock(&session->s_cap_lock);
2648                 wake_up_session_caps(session, 0);
2649                 break;
2650
2651         default:
2652                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2653                 WARN_ON(1);
2654         }
2655
2656         mutex_unlock(&session->s_mutex);
2657         if (wake) {
2658                 mutex_lock(&mdsc->mutex);
2659                 __wake_requests(mdsc, &session->s_waiting);
2660                 if (wake == 2)
2661                         kick_requests(mdsc, mds);
2662                 mutex_unlock(&mdsc->mutex);
2663         }
2664         return;
2665
2666 bad:
2667         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2668                (int)msg->front.iov_len);
2669         ceph_msg_dump(msg);
2670         return;
2671 }
2672
2673
2674 /*
2675  * called under session->mutex.
2676  */
2677 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2678                                    struct ceph_mds_session *session)
2679 {
2680         struct ceph_mds_request *req, *nreq;
2681         struct rb_node *p;
2682         int err;
2683
2684         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2685
2686         mutex_lock(&mdsc->mutex);
2687         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2688                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
2689                 if (!err) {
2690                         ceph_msg_get(req->r_request);
2691                         ceph_con_send(&session->s_con, req->r_request);
2692                 }
2693         }
2694
2695         /*
2696          * also re-send old requests when MDS enters reconnect stage. So that MDS
2697          * can process completed request in clientreplay stage.
2698          */
2699         p = rb_first(&mdsc->request_tree);
2700         while (p) {
2701                 req = rb_entry(p, struct ceph_mds_request, r_node);
2702                 p = rb_next(p);
2703                 if (req->r_got_unsafe)
2704                         continue;
2705                 if (req->r_attempts == 0)
2706                         continue; /* only old requests */
2707                 if (req->r_session &&
2708                     req->r_session->s_mds == session->s_mds) {
2709                         err = __prepare_send_request(mdsc, req,
2710                                                      session->s_mds, true);
2711                         if (!err) {
2712                                 ceph_msg_get(req->r_request);
2713                                 ceph_con_send(&session->s_con, req->r_request);
2714                         }
2715                 }
2716         }
2717         mutex_unlock(&mdsc->mutex);
2718 }
2719
2720 /*
2721  * Encode information about a cap for a reconnect with the MDS.
2722  */
2723 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2724                           void *arg)
2725 {
2726         union {
2727                 struct ceph_mds_cap_reconnect v2;
2728                 struct ceph_mds_cap_reconnect_v1 v1;
2729         } rec;
2730         size_t reclen;
2731         struct ceph_inode_info *ci;
2732         struct ceph_reconnect_state *recon_state = arg;
2733         struct ceph_pagelist *pagelist = recon_state->pagelist;
2734         char *path;
2735         int pathlen, err;
2736         u64 pathbase;
2737         struct dentry *dentry;
2738
2739         ci = cap->ci;
2740
2741         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2742              inode, ceph_vinop(inode), cap, cap->cap_id,
2743              ceph_cap_string(cap->issued));
2744         err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2745         if (err)
2746                 return err;
2747
2748         dentry = d_find_alias(inode);
2749         if (dentry) {
2750                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2751                 if (IS_ERR(path)) {
2752                         err = PTR_ERR(path);
2753                         goto out_dput;
2754                 }
2755         } else {
2756                 path = NULL;
2757                 pathlen = 0;
2758         }
2759         err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2760         if (err)
2761                 goto out_free;
2762
2763         spin_lock(&ci->i_ceph_lock);
2764         cap->seq = 0;        /* reset cap seq */
2765         cap->issue_seq = 0;  /* and issue_seq */
2766         cap->mseq = 0;       /* and migrate_seq */
2767         cap->cap_gen = cap->session->s_cap_gen;
2768
2769         if (recon_state->flock) {
2770                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2771                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2772                 rec.v2.issued = cpu_to_le32(cap->issued);
2773                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2774                 rec.v2.pathbase = cpu_to_le64(pathbase);
2775                 rec.v2.flock_len = 0;
2776                 reclen = sizeof(rec.v2);
2777         } else {
2778                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2779                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2780                 rec.v1.issued = cpu_to_le32(cap->issued);
2781                 rec.v1.size = cpu_to_le64(inode->i_size);
2782                 ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2783                 ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2784                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2785                 rec.v1.pathbase = cpu_to_le64(pathbase);
2786                 reclen = sizeof(rec.v1);
2787         }
2788         spin_unlock(&ci->i_ceph_lock);
2789
2790         if (recon_state->flock) {
2791                 int num_fcntl_locks, num_flock_locks;
2792                 struct ceph_filelock *flocks;
2793
2794 encode_again:
2795                 ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2796                 flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2797                                  sizeof(struct ceph_filelock), GFP_NOFS);
2798                 if (!flocks) {
2799                         err = -ENOMEM;
2800                         goto out_free;
2801                 }
2802                 err = ceph_encode_locks_to_buffer(inode, flocks,
2803                                                   num_fcntl_locks,
2804                                                   num_flock_locks);
2805                 if (err) {
2806                         kfree(flocks);
2807                         if (err == -ENOSPC)
2808                                 goto encode_again;
2809                         goto out_free;
2810                 }
2811                 /*
2812                  * number of encoded locks is stable, so copy to pagelist
2813                  */
2814                 rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2815                                     (num_fcntl_locks+num_flock_locks) *
2816                                     sizeof(struct ceph_filelock));
2817                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2818                 if (!err)
2819                         err = ceph_locks_to_pagelist(flocks, pagelist,
2820                                                      num_fcntl_locks,
2821                                                      num_flock_locks);
2822                 kfree(flocks);
2823         } else {
2824                 err = ceph_pagelist_append(pagelist, &rec, reclen);
2825         }
2826
2827         recon_state->nr_caps++;
2828 out_free:
2829         kfree(path);
2830 out_dput:
2831         dput(dentry);
2832         return err;
2833 }
2834
2835
2836 /*
2837  * If an MDS fails and recovers, clients need to reconnect in order to
2838  * reestablish shared state.  This includes all caps issued through
2839  * this session _and_ the snap_realm hierarchy.  Because it's not
2840  * clear which snap realms the mds cares about, we send everything we
2841  * know about.. that ensures we'll then get any new info the
2842  * recovering MDS might have.
2843  *
2844  * This is a relatively heavyweight operation, but it's rare.
2845  *
2846  * called with mdsc->mutex held.
2847  */
2848 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2849                                struct ceph_mds_session *session)
2850 {
2851         struct ceph_msg *reply;
2852         struct rb_node *p;
2853         int mds = session->s_mds;
2854         int err = -ENOMEM;
2855         int s_nr_caps;
2856         struct ceph_pagelist *pagelist;
2857         struct ceph_reconnect_state recon_state;
2858
2859         pr_info("mds%d reconnect start\n", mds);
2860
2861         pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2862         if (!pagelist)
2863                 goto fail_nopagelist;
2864         ceph_pagelist_init(pagelist);
2865
2866         reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2867         if (!reply)
2868                 goto fail_nomsg;
2869
2870         mutex_lock(&session->s_mutex);
2871         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2872         session->s_seq = 0;
2873
2874         dout("session %p state %s\n", session,
2875              ceph_session_state_name(session->s_state));
2876
2877         spin_lock(&session->s_gen_ttl_lock);
2878         session->s_cap_gen++;
2879         spin_unlock(&session->s_gen_ttl_lock);
2880
2881         spin_lock(&session->s_cap_lock);
2882         /* don't know if session is readonly */
2883         session->s_readonly = 0;
2884         /*
2885          * notify __ceph_remove_cap() that we are composing cap reconnect.
2886          * If a cap get released before being added to the cap reconnect,
2887          * __ceph_remove_cap() should skip queuing cap release.
2888          */
2889         session->s_cap_reconnect = 1;
2890         /* drop old cap expires; we're about to reestablish that state */
2891         discard_cap_releases(mdsc, session);
2892         spin_unlock(&session->s_cap_lock);
2893
2894         /* trim unused caps to reduce MDS's cache rejoin time */
2895         if (mdsc->fsc->sb->s_root)
2896                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
2897
2898         ceph_con_close(&session->s_con);
2899         ceph_con_open(&session->s_con,
2900                       CEPH_ENTITY_TYPE_MDS, mds,
2901                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2902
2903         /* replay unsafe requests */
2904         replay_unsafe_requests(mdsc, session);
2905
2906         down_read(&mdsc->snap_rwsem);
2907
2908         /* traverse this session's caps */
2909         s_nr_caps = session->s_nr_caps;
2910         err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2911         if (err)
2912                 goto fail;
2913
2914         recon_state.nr_caps = 0;
2915         recon_state.pagelist = pagelist;
2916         recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2917         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2918         if (err < 0)
2919                 goto fail;
2920
2921         spin_lock(&session->s_cap_lock);
2922         session->s_cap_reconnect = 0;
2923         spin_unlock(&session->s_cap_lock);
2924
2925         /*
2926          * snaprealms.  we provide mds with the ino, seq (version), and
2927          * parent for all of our realms.  If the mds has any newer info,
2928          * it will tell us.
2929          */
2930         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2931                 struct ceph_snap_realm *realm =
2932                         rb_entry(p, struct ceph_snap_realm, node);
2933                 struct ceph_mds_snaprealm_reconnect sr_rec;
2934
2935                 dout(" adding snap realm %llx seq %lld parent %llx\n",
2936                      realm->ino, realm->seq, realm->parent_ino);
2937                 sr_rec.ino = cpu_to_le64(realm->ino);
2938                 sr_rec.seq = cpu_to_le64(realm->seq);
2939                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
2940                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2941                 if (err)
2942                         goto fail;
2943         }
2944
2945         if (recon_state.flock)
2946                 reply->hdr.version = cpu_to_le16(2);
2947
2948         /* raced with cap release? */
2949         if (s_nr_caps != recon_state.nr_caps) {
2950                 struct page *page = list_first_entry(&pagelist->head,
2951                                                      struct page, lru);
2952                 __le32 *addr = kmap_atomic(page);
2953                 *addr = cpu_to_le32(recon_state.nr_caps);
2954                 kunmap_atomic(addr);
2955         }
2956
2957         reply->hdr.data_len = cpu_to_le32(pagelist->length);
2958         ceph_msg_data_add_pagelist(reply, pagelist);
2959         ceph_con_send(&session->s_con, reply);
2960
2961         mutex_unlock(&session->s_mutex);
2962
2963         mutex_lock(&mdsc->mutex);
2964         __wake_requests(mdsc, &session->s_waiting);
2965         mutex_unlock(&mdsc->mutex);
2966
2967         up_read(&mdsc->snap_rwsem);
2968         return;
2969
2970 fail:
2971         ceph_msg_put(reply);
2972         up_read(&mdsc->snap_rwsem);
2973         mutex_unlock(&session->s_mutex);
2974 fail_nomsg:
2975         ceph_pagelist_release(pagelist);
2976 fail_nopagelist:
2977         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
2978         return;
2979 }
2980
2981
2982 /*
2983  * compare old and new mdsmaps, kicking requests
2984  * and closing out old connections as necessary
2985  *
2986  * called under mdsc->mutex.
2987  */
2988 static void check_new_map(struct ceph_mds_client *mdsc,
2989                           struct ceph_mdsmap *newmap,
2990                           struct ceph_mdsmap *oldmap)
2991 {
2992         int i;
2993         int oldstate, newstate;
2994         struct ceph_mds_session *s;
2995
2996         dout("check_new_map new %u old %u\n",
2997              newmap->m_epoch, oldmap->m_epoch);
2998
2999         for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
3000                 if (mdsc->sessions[i] == NULL)
3001                         continue;
3002                 s = mdsc->sessions[i];
3003                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3004                 newstate = ceph_mdsmap_get_state(newmap, i);
3005
3006                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3007                      i, ceph_mds_state_name(oldstate),
3008                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3009                      ceph_mds_state_name(newstate),
3010                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3011                      ceph_session_state_name(s->s_state));
3012
3013                 if (i >= newmap->m_max_mds ||
3014                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
3015                            ceph_mdsmap_get_addr(newmap, i),
3016                            sizeof(struct ceph_entity_addr))) {
3017                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
3018                                 /* the session never opened, just close it
3019                                  * out now */
3020                                 __wake_requests(mdsc, &s->s_waiting);
3021                                 __unregister_session(mdsc, s);
3022                         } else {
3023                                 /* just close it */
3024                                 mutex_unlock(&mdsc->mutex);
3025                                 mutex_lock(&s->s_mutex);
3026                                 mutex_lock(&mdsc->mutex);
3027                                 ceph_con_close(&s->s_con);
3028                                 mutex_unlock(&s->s_mutex);
3029                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
3030                         }
3031                 } else if (oldstate == newstate) {
3032                         continue;  /* nothing new with this mds */
3033                 }
3034
3035                 /*
3036                  * send reconnect?
3037                  */
3038                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3039                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3040                         mutex_unlock(&mdsc->mutex);
3041                         send_mds_reconnect(mdsc, s);
3042                         mutex_lock(&mdsc->mutex);
3043                 }
3044
3045                 /*
3046                  * kick request on any mds that has gone active.
3047                  */
3048                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3049                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3050                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3051                             oldstate != CEPH_MDS_STATE_STARTING)
3052                                 pr_info("mds%d recovery completed\n", s->s_mds);
3053                         kick_requests(mdsc, i);
3054                         ceph_kick_flushing_caps(mdsc, s);
3055                         wake_up_session_caps(s, 1);
3056                 }
3057         }
3058
3059         for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
3060                 s = mdsc->sessions[i];
3061                 if (!s)
3062                         continue;
3063                 if (!ceph_mdsmap_is_laggy(newmap, i))
3064                         continue;
3065                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3066                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3067                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3068                         dout(" connecting to export targets of laggy mds%d\n",
3069                              i);
3070                         __open_export_target_sessions(mdsc, s);
3071                 }
3072         }
3073 }
3074
3075
3076
3077 /*
3078  * leases
3079  */
3080
3081 /*
3082  * caller must hold session s_mutex, dentry->d_lock
3083  */
3084 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3085 {
3086         struct ceph_dentry_info *di = ceph_dentry(dentry);
3087
3088         ceph_put_mds_session(di->lease_session);
3089         di->lease_session = NULL;
3090 }
3091
3092 static void handle_lease(struct ceph_mds_client *mdsc,
3093                          struct ceph_mds_session *session,
3094                          struct ceph_msg *msg)
3095 {
3096         struct super_block *sb = mdsc->fsc->sb;
3097         struct inode *inode;
3098         struct dentry *parent, *dentry;
3099         struct ceph_dentry_info *di;
3100         int mds = session->s_mds;
3101         struct ceph_mds_lease *h = msg->front.iov_base;
3102         u32 seq;
3103         struct ceph_vino vino;
3104         struct qstr dname;
3105         int release = 0;
3106
3107         dout("handle_lease from mds%d\n", mds);
3108
3109         /* decode */
3110         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3111                 goto bad;
3112         vino.ino = le64_to_cpu(h->ino);
3113         vino.snap = CEPH_NOSNAP;
3114         seq = le32_to_cpu(h->seq);
3115         dname.name = (void *)h + sizeof(*h) + sizeof(u32);
3116         dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
3117         if (dname.len != get_unaligned_le32(h+1))
3118                 goto bad;
3119
3120         /* lookup inode */
3121         inode = ceph_find_inode(sb, vino);
3122         dout("handle_lease %s, ino %llx %p %.*s\n",
3123              ceph_lease_op_name(h->action), vino.ino, inode,
3124              dname.len, dname.name);
3125
3126         mutex_lock(&session->s_mutex);
3127         session->s_seq++;
3128
3129         if (inode == NULL) {
3130                 dout("handle_lease no inode %llx\n", vino.ino);
3131                 goto release;
3132         }
3133
3134         /* dentry */
3135         parent = d_find_alias(inode);
3136         if (!parent) {
3137                 dout("no parent dentry on inode %p\n", inode);
3138                 WARN_ON(1);
3139                 goto release;  /* hrm... */
3140         }
3141         dname.hash = full_name_hash(dname.name, dname.len);
3142         dentry = d_lookup(parent, &dname);
3143         dput(parent);
3144         if (!dentry)
3145                 goto release;
3146
3147         spin_lock(&dentry->d_lock);
3148         di = ceph_dentry(dentry);
3149         switch (h->action) {
3150         case CEPH_MDS_LEASE_REVOKE:
3151                 if (di->lease_session == session) {
3152                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3153                                 h->seq = cpu_to_le32(di->lease_seq);
3154                         __ceph_mdsc_drop_dentry_lease(dentry);
3155                 }
3156                 release = 1;
3157                 break;
3158
3159         case CEPH_MDS_LEASE_RENEW:
3160                 if (di->lease_session == session &&
3161                     di->lease_gen == session->s_cap_gen &&
3162                     di->lease_renew_from &&
3163                     di->lease_renew_after == 0) {
3164                         unsigned long duration =
3165                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3166
3167                         di->lease_seq = seq;
3168                         dentry->d_time = di->lease_renew_from + duration;
3169                         di->lease_renew_after = di->lease_renew_from +
3170                                 (duration >> 1);
3171                         di->lease_renew_from = 0;
3172                 }
3173                 break;
3174         }
3175         spin_unlock(&dentry->d_lock);
3176         dput(dentry);
3177
3178         if (!release)
3179                 goto out;
3180
3181 release:
3182         /* let's just reuse the same message */
3183         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3184         ceph_msg_get(msg);
3185         ceph_con_send(&session->s_con, msg);
3186
3187 out:
3188         iput(inode);
3189         mutex_unlock(&session->s_mutex);
3190         return;
3191
3192 bad:
3193         pr_err("corrupt lease message\n");
3194         ceph_msg_dump(msg);
3195 }
3196
3197 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3198                               struct inode *inode,
3199                               struct dentry *dentry, char action,
3200                               u32 seq)
3201 {
3202         struct ceph_msg *msg;
3203         struct ceph_mds_lease *lease;
3204         int len = sizeof(*lease) + sizeof(u32);
3205         int dnamelen = 0;
3206
3207         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3208              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3209         dnamelen = dentry->d_name.len;
3210         len += dnamelen;
3211
3212         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3213         if (!msg)
3214                 return;
3215         lease = msg->front.iov_base;
3216         lease->action = action;
3217         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3218         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3219         lease->seq = cpu_to_le32(seq);
3220         put_unaligned_le32(dnamelen, lease + 1);
3221         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3222
3223         /*
3224          * if this is a preemptive lease RELEASE, no need to
3225          * flush request stream, since the actual request will
3226          * soon follow.
3227          */
3228         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3229
3230         ceph_con_send(&session->s_con, msg);
3231 }
3232
3233 /*
3234  * Preemptively release a lease we expect to invalidate anyway.
3235  * Pass @inode always, @dentry is optional.
3236  */
3237 void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
3238                              struct dentry *dentry)
3239 {
3240         struct ceph_dentry_info *di;
3241         struct ceph_mds_session *session;
3242         u32 seq;
3243
3244         BUG_ON(inode == NULL);
3245         BUG_ON(dentry == NULL);
3246
3247         /* is dentry lease valid? */
3248         spin_lock(&dentry->d_lock);
3249         di = ceph_dentry(dentry);
3250         if (!di || !di->lease_session ||
3251             di->lease_session->s_mds < 0 ||
3252             di->lease_gen != di->lease_session->s_cap_gen ||
3253             !time_before(jiffies, dentry->d_time)) {
3254                 dout("lease_release inode %p dentry %p -- "
3255                      "no lease\n",
3256                      inode, dentry);
3257                 spin_unlock(&dentry->d_lock);
3258                 return;
3259         }
3260
3261         /* we do have a lease on this dentry; note mds and seq */
3262         session = ceph_get_mds_session(di->lease_session);
3263         seq = di->lease_seq;
3264         __ceph_mdsc_drop_dentry_lease(dentry);
3265         spin_unlock(&dentry->d_lock);
3266
3267         dout("lease_release inode %p dentry %p to mds%d\n",
3268              inode, dentry, session->s_mds);
3269         ceph_mdsc_lease_send_msg(session, inode, dentry,
3270                                  CEPH_MDS_LEASE_RELEASE, seq);
3271         ceph_put_mds_session(session);
3272 }
3273
3274 /*
3275  * drop all leases (and dentry refs) in preparation for umount
3276  */
3277 static void drop_leases(struct ceph_mds_client *mdsc)
3278 {
3279         int i;
3280
3281         dout("drop_leases\n");
3282         mutex_lock(&mdsc->mutex);
3283         for (i = 0; i < mdsc->max_sessions; i++) {
3284                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3285                 if (!s)
3286                         continue;
3287                 mutex_unlock(&mdsc->mutex);
3288                 mutex_lock(&s->s_mutex);
3289                 mutex_unlock(&s->s_mutex);
3290                 ceph_put_mds_session(s);
3291                 mutex_lock(&mdsc->mutex);
3292         }
3293         mutex_unlock(&mdsc->mutex);
3294 }
3295
3296
3297
3298 /*
3299  * delayed work -- periodically trim expired leases, renew caps with mds
3300  */
3301 static void schedule_delayed(struct ceph_mds_client *mdsc)
3302 {
3303         int delay = 5;
3304         unsigned hz = round_jiffies_relative(HZ * delay);
3305         schedule_delayed_work(&mdsc->delayed_work, hz);
3306 }
3307
3308 static void delayed_work(struct work_struct *work)
3309 {
3310         int i;
3311         struct ceph_mds_client *mdsc =
3312                 container_of(work, struct ceph_mds_client, delayed_work.work);
3313         int renew_interval;
3314         int renew_caps;
3315
3316         dout("mdsc delayed_work\n");
3317         ceph_check_delayed_caps(mdsc);
3318
3319         mutex_lock(&mdsc->mutex);
3320         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3321         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3322                                    mdsc->last_renew_caps);
3323         if (renew_caps)
3324                 mdsc->last_renew_caps = jiffies;
3325
3326         for (i = 0; i < mdsc->max_sessions; i++) {
3327                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3328                 if (s == NULL)
3329                         continue;
3330                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3331                         dout("resending session close request for mds%d\n",
3332                              s->s_mds);
3333                         request_close_session(mdsc, s);
3334                         ceph_put_mds_session(s);
3335                         continue;
3336                 }
3337                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3338                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3339                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3340                                 pr_info("mds%d hung\n", s->s_mds);
3341                         }
3342                 }
3343                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3344                         /* this mds is failed or recovering, just wait */
3345                         ceph_put_mds_session(s);
3346                         continue;
3347                 }
3348                 mutex_unlock(&mdsc->mutex);
3349
3350                 mutex_lock(&s->s_mutex);
3351                 if (renew_caps)
3352                         send_renew_caps(mdsc, s);
3353                 else
3354                         ceph_con_keepalive(&s->s_con);
3355                 ceph_add_cap_releases(mdsc, s);
3356                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3357                     s->s_state == CEPH_MDS_SESSION_HUNG)
3358                         ceph_send_cap_releases(mdsc, s);
3359                 mutex_unlock(&s->s_mutex);
3360                 ceph_put_mds_session(s);
3361
3362                 mutex_lock(&mdsc->mutex);
3363         }
3364         mutex_unlock(&mdsc->mutex);
3365
3366         schedule_delayed(mdsc);
3367 }
3368
3369 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3370
3371 {
3372         struct ceph_mds_client *mdsc;
3373
3374         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3375         if (!mdsc)
3376                 return -ENOMEM;
3377         mdsc->fsc = fsc;
3378         fsc->mdsc = mdsc;
3379         mutex_init(&mdsc->mutex);
3380         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3381         if (mdsc->mdsmap == NULL) {
3382                 kfree(mdsc);
3383                 return -ENOMEM;
3384         }
3385
3386         init_completion(&mdsc->safe_umount_waiters);
3387         init_waitqueue_head(&mdsc->session_close_wq);
3388         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3389         mdsc->sessions = NULL;
3390         atomic_set(&mdsc->num_sessions, 0);
3391         mdsc->max_sessions = 0;
3392         mdsc->stopping = 0;
3393         init_rwsem(&mdsc->snap_rwsem);
3394         mdsc->snap_realms = RB_ROOT;
3395         INIT_LIST_HEAD(&mdsc->snap_empty);
3396         spin_lock_init(&mdsc->snap_empty_lock);
3397         mdsc->last_tid = 0;
3398         mdsc->request_tree = RB_ROOT;
3399         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3400         mdsc->last_renew_caps = jiffies;
3401         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3402         spin_lock_init(&mdsc->cap_delay_lock);
3403         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3404         spin_lock_init(&mdsc->snap_flush_lock);
3405         mdsc->cap_flush_seq = 0;
3406         INIT_LIST_HEAD(&mdsc->cap_dirty);
3407         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3408         mdsc->num_cap_flushing = 0;
3409         spin_lock_init(&mdsc->cap_dirty_lock);
3410         init_waitqueue_head(&mdsc->cap_flushing_wq);
3411         spin_lock_init(&mdsc->dentry_lru_lock);
3412         INIT_LIST_HEAD(&mdsc->dentry_lru);
3413
3414         ceph_caps_init(mdsc);
3415         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3416
3417         return 0;
3418 }
3419
3420 /*
3421  * Wait for safe replies on open mds requests.  If we time out, drop
3422  * all requests from the tree to avoid dangling dentry refs.
3423  */
3424 static void wait_requests(struct ceph_mds_client *mdsc)
3425 {
3426         struct ceph_mds_request *req;
3427         struct ceph_fs_client *fsc = mdsc->fsc;
3428
3429         mutex_lock(&mdsc->mutex);
3430         if (__get_oldest_req(mdsc)) {
3431                 mutex_unlock(&mdsc->mutex);
3432
3433                 dout("wait_requests waiting for requests\n");
3434                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3435                                     fsc->client->options->mount_timeout * HZ);
3436
3437                 /* tear down remaining requests */
3438                 mutex_lock(&mdsc->mutex);
3439                 while ((req = __get_oldest_req(mdsc))) {
3440                         dout("wait_requests timed out on tid %llu\n",
3441                              req->r_tid);
3442                         __unregister_request(mdsc, req);
3443                 }
3444         }
3445         mutex_unlock(&mdsc->mutex);
3446         dout("wait_requests done\n");
3447 }
3448
3449 /*
3450  * called before mount is ro, and before dentries are torn down.
3451  * (hmm, does this still race with new lookups?)
3452  */
3453 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3454 {
3455         dout("pre_umount\n");
3456         mdsc->stopping = 1;
3457
3458         drop_leases(mdsc);
3459         ceph_flush_dirty_caps(mdsc);
3460         wait_requests(mdsc);
3461
3462         /*
3463          * wait for reply handlers to drop their request refs and
3464          * their inode/dcache refs
3465          */
3466         ceph_msgr_flush();
3467 }
3468
3469 /*
3470  * wait for all write mds requests to flush.
3471  */
3472 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3473 {
3474         struct ceph_mds_request *req = NULL, *nextreq;
3475         struct rb_node *n;
3476
3477         mutex_lock(&mdsc->mutex);
3478         dout("wait_unsafe_requests want %lld\n", want_tid);
3479 restart:
3480         req = __get_oldest_req(mdsc);
3481         while (req && req->r_tid <= want_tid) {
3482                 /* find next request */
3483                 n = rb_next(&req->r_node);
3484                 if (n)
3485                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3486                 else
3487                         nextreq = NULL;
3488                 if ((req->r_op & CEPH_MDS_OP_WRITE)) {
3489                         /* write op */
3490                         ceph_mdsc_get_request(req);
3491                         if (nextreq)
3492                                 ceph_mdsc_get_request(nextreq);
3493                         mutex_unlock(&mdsc->mutex);
3494                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3495                              req->r_tid, want_tid);
3496                         wait_for_completion(&req->r_safe_completion);
3497                         mutex_lock(&mdsc->mutex);
3498                         ceph_mdsc_put_request(req);
3499                         if (!nextreq)
3500                                 break;  /* next dne before, so we're done! */
3501                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3502                                 /* next request was removed from tree */
3503                                 ceph_mdsc_put_request(nextreq);
3504                                 goto restart;
3505                         }
3506                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3507                 }
3508                 req = nextreq;
3509         }
3510         mutex_unlock(&mdsc->mutex);
3511         dout("wait_unsafe_requests done\n");
3512 }
3513
3514 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3515 {
3516         u64 want_tid, want_flush;
3517
3518         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3519                 return;
3520
3521         dout("sync\n");
3522         mutex_lock(&mdsc->mutex);
3523         want_tid = mdsc->last_tid;
3524         mutex_unlock(&mdsc->mutex);
3525
3526         ceph_flush_dirty_caps(mdsc);
3527         spin_lock(&mdsc->cap_dirty_lock);
3528         want_flush = mdsc->cap_flush_seq;
3529         spin_unlock(&mdsc->cap_dirty_lock);
3530
3531         dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush);
3532
3533         wait_unsafe_requests(mdsc, want_tid);
3534         wait_caps_flush(mdsc, want_flush);
3535 }
3536
3537 /*
3538  * true if all sessions are closed, or we force unmount
3539  */
3540 static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3541 {
3542         if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3543                 return true;
3544         return atomic_read(&mdsc->num_sessions) == 0;
3545 }
3546
3547 /*
3548  * called after sb is ro.
3549  */
3550 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3551 {
3552         struct ceph_mds_session *session;
3553         int i;
3554         struct ceph_fs_client *fsc = mdsc->fsc;
3555         unsigned long timeout = fsc->client->options->mount_timeout * HZ;
3556
3557         dout("close_sessions\n");
3558
3559         /* close sessions */
3560         mutex_lock(&mdsc->mutex);
3561         for (i = 0; i < mdsc->max_sessions; i++) {
3562                 session = __ceph_lookup_mds_session(mdsc, i);
3563                 if (!session)
3564                         continue;
3565                 mutex_unlock(&mdsc->mutex);
3566                 mutex_lock(&session->s_mutex);
3567                 __close_session(mdsc, session);
3568                 mutex_unlock(&session->s_mutex);
3569                 ceph_put_mds_session(session);
3570                 mutex_lock(&mdsc->mutex);
3571         }
3572         mutex_unlock(&mdsc->mutex);
3573
3574         dout("waiting for sessions to close\n");
3575         wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3576                            timeout);
3577
3578         /* tear down remaining sessions */
3579         mutex_lock(&mdsc->mutex);
3580         for (i = 0; i < mdsc->max_sessions; i++) {
3581                 if (mdsc->sessions[i]) {
3582                         session = get_session(mdsc->sessions[i]);
3583                         __unregister_session(mdsc, session);
3584                         mutex_unlock(&mdsc->mutex);
3585                         mutex_lock(&session->s_mutex);
3586                         remove_session_caps(session);
3587                         mutex_unlock(&session->s_mutex);
3588                         ceph_put_mds_session(session);
3589                         mutex_lock(&mdsc->mutex);
3590                 }
3591         }
3592         WARN_ON(!list_empty(&mdsc->cap_delay_list));
3593         mutex_unlock(&mdsc->mutex);
3594
3595         ceph_cleanup_empty_realms(mdsc);
3596
3597         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3598
3599         dout("stopped\n");
3600 }
3601
3602 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3603 {
3604         dout("stop\n");
3605         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3606         if (mdsc->mdsmap)
3607                 ceph_mdsmap_destroy(mdsc->mdsmap);
3608         kfree(mdsc->sessions);
3609         ceph_caps_finalize(mdsc);
3610 }
3611
3612 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3613 {
3614         struct ceph_mds_client *mdsc = fsc->mdsc;
3615
3616         dout("mdsc_destroy %p\n", mdsc);
3617         ceph_mdsc_stop(mdsc);
3618
3619         /* flush out any connection work with references to us */
3620         ceph_msgr_flush();
3621
3622         fsc->mdsc = NULL;
3623         kfree(mdsc);
3624         dout("mdsc_destroy %p done\n", mdsc);
3625 }
3626
3627
3628 /*
3629  * handle mds map update.
3630  */
3631 void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3632 {
3633         u32 epoch;
3634         u32 maplen;
3635         void *p = msg->front.iov_base;
3636         void *end = p + msg->front.iov_len;
3637         struct ceph_mdsmap *newmap, *oldmap;
3638         struct ceph_fsid fsid;
3639         int err = -EINVAL;
3640
3641         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3642         ceph_decode_copy(&p, &fsid, sizeof(fsid));
3643         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3644                 return;
3645         epoch = ceph_decode_32(&p);
3646         maplen = ceph_decode_32(&p);
3647         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3648
3649         /* do we need it? */
3650         ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
3651         mutex_lock(&mdsc->mutex);
3652         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3653                 dout("handle_map epoch %u <= our %u\n",
3654                      epoch, mdsc->mdsmap->m_epoch);
3655                 mutex_unlock(&mdsc->mutex);
3656                 return;
3657         }
3658
3659         newmap = ceph_mdsmap_decode(&p, end);
3660         if (IS_ERR(newmap)) {
3661                 err = PTR_ERR(newmap);
3662                 goto bad_unlock;
3663         }
3664
3665         /* swap into place */
3666         if (mdsc->mdsmap) {
3667                 oldmap = mdsc->mdsmap;
3668                 mdsc->mdsmap = newmap;
3669                 check_new_map(mdsc, newmap, oldmap);
3670                 ceph_mdsmap_destroy(oldmap);
3671         } else {
3672                 mdsc->mdsmap = newmap;  /* first mds map */
3673         }
3674         mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3675
3676         __wake_requests(mdsc, &mdsc->waiting_for_map);
3677
3678         mutex_unlock(&mdsc->mutex);
3679         schedule_delayed(mdsc);
3680         return;
3681
3682 bad_unlock:
3683         mutex_unlock(&mdsc->mutex);
3684 bad:
3685         pr_err("error decoding mdsmap %d\n", err);
3686         return;
3687 }
3688
3689 static struct ceph_connection *con_get(struct ceph_connection *con)
3690 {
3691         struct ceph_mds_session *s = con->private;
3692
3693         if (get_session(s)) {
3694                 dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3695                 return con;
3696         }
3697         dout("mdsc con_get %p FAIL\n", s);
3698         return NULL;
3699 }
3700
3701 static void con_put(struct ceph_connection *con)
3702 {
3703         struct ceph_mds_session *s = con->private;
3704
3705         dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3706         ceph_put_mds_session(s);
3707 }
3708
3709 /*
3710  * if the client is unresponsive for long enough, the mds will kill
3711  * the session entirely.
3712  */
3713 static void peer_reset(struct ceph_connection *con)
3714 {
3715         struct ceph_mds_session *s = con->private;
3716         struct ceph_mds_client *mdsc = s->s_mdsc;
3717
3718         pr_warn("mds%d closed our session\n", s->s_mds);
3719         send_mds_reconnect(mdsc, s);
3720 }
3721
3722 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3723 {
3724         struct ceph_mds_session *s = con->private;
3725         struct ceph_mds_client *mdsc = s->s_mdsc;
3726         int type = le16_to_cpu(msg->hdr.type);
3727
3728         mutex_lock(&mdsc->mutex);
3729         if (__verify_registered_session(mdsc, s) < 0) {
3730                 mutex_unlock(&mdsc->mutex);
3731                 goto out;
3732         }
3733         mutex_unlock(&mdsc->mutex);
3734
3735         switch (type) {
3736         case CEPH_MSG_MDS_MAP:
3737                 ceph_mdsc_handle_map(mdsc, msg);
3738                 break;
3739         case CEPH_MSG_CLIENT_SESSION:
3740                 handle_session(s, msg);
3741                 break;
3742         case CEPH_MSG_CLIENT_REPLY:
3743                 handle_reply(s, msg);
3744                 break;
3745         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3746                 handle_forward(mdsc, s, msg);
3747                 break;
3748         case CEPH_MSG_CLIENT_CAPS:
3749                 ceph_handle_caps(s, msg);
3750                 break;
3751         case CEPH_MSG_CLIENT_SNAP:
3752                 ceph_handle_snap(mdsc, s, msg);
3753                 break;
3754         case CEPH_MSG_CLIENT_LEASE:
3755                 handle_lease(mdsc, s, msg);
3756                 break;
3757
3758         default:
3759                 pr_err("received unknown message type %d %s\n", type,
3760                        ceph_msg_type_name(type));
3761         }
3762 out:
3763         ceph_msg_put(msg);
3764 }
3765
3766 /*
3767  * authentication
3768  */
3769
3770 /*
3771  * Note: returned pointer is the address of a structure that's
3772  * managed separately.  Caller must *not* attempt to free it.
3773  */
3774 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3775                                         int *proto, int force_new)
3776 {
3777         struct ceph_mds_session *s = con->private;
3778         struct ceph_mds_client *mdsc = s->s_mdsc;
3779         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3780         struct ceph_auth_handshake *auth = &s->s_auth;
3781
3782         if (force_new && auth->authorizer) {
3783                 ceph_auth_destroy_authorizer(ac, auth->authorizer);
3784                 auth->authorizer = NULL;
3785         }
3786         if (!auth->authorizer) {
3787                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3788                                                       auth);
3789                 if (ret)
3790                         return ERR_PTR(ret);
3791         } else {
3792                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3793                                                       auth);
3794                 if (ret)
3795                         return ERR_PTR(ret);
3796         }
3797         *proto = ac->protocol;
3798
3799         return auth;
3800 }
3801
3802
3803 static int verify_authorizer_reply(struct ceph_connection *con, int len)
3804 {
3805         struct ceph_mds_session *s = con->private;
3806         struct ceph_mds_client *mdsc = s->s_mdsc;
3807         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3808
3809         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3810 }
3811
3812 static int invalidate_authorizer(struct ceph_connection *con)
3813 {
3814         struct ceph_mds_session *s = con->private;
3815         struct ceph_mds_client *mdsc = s->s_mdsc;
3816         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3817
3818         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3819
3820         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3821 }
3822
3823 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3824                                 struct ceph_msg_header *hdr, int *skip)
3825 {
3826         struct ceph_msg *msg;
3827         int type = (int) le16_to_cpu(hdr->type);
3828         int front_len = (int) le32_to_cpu(hdr->front_len);
3829
3830         if (con->in_msg)
3831                 return con->in_msg;
3832
3833         *skip = 0;
3834         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3835         if (!msg) {
3836                 pr_err("unable to allocate msg type %d len %d\n",
3837                        type, front_len);
3838                 return NULL;
3839         }
3840
3841         return msg;
3842 }
3843
3844 static int sign_message(struct ceph_connection *con, struct ceph_msg *msg)
3845 {
3846        struct ceph_mds_session *s = con->private;
3847        struct ceph_auth_handshake *auth = &s->s_auth;
3848        return ceph_auth_sign_message(auth, msg);
3849 }
3850
3851 static int check_message_signature(struct ceph_connection *con, struct ceph_msg *msg)
3852 {
3853        struct ceph_mds_session *s = con->private;
3854        struct ceph_auth_handshake *auth = &s->s_auth;
3855        return ceph_auth_check_message_signature(auth, msg);
3856 }
3857
3858 static const struct ceph_connection_operations mds_con_ops = {
3859         .get = con_get,
3860         .put = con_put,
3861         .dispatch = dispatch,
3862         .get_authorizer = get_authorizer,
3863         .verify_authorizer_reply = verify_authorizer_reply,
3864         .invalidate_authorizer = invalidate_authorizer,
3865         .peer_reset = peer_reset,
3866         .alloc_msg = mds_alloc_msg,
3867         .sign_message = sign_message,
3868         .check_message_signature = check_message_signature,
3869 };
3870
3871 /* eof */