fs/ceph/mds_client.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/ceph/ceph_debug.h>
   3
   4 #include <linux/fs.h>
   5 #include <linux/wait.h>
   6 #include <linux/slab.h>
   7 #include <linux/gfp.h>
   8 #include <linux/sched.h>
   9 #include <linux/debugfs.h>
  10 #include <linux/seq_file.h>
  11 #include <linux/ratelimit.h>
  12
  13 #include "super.h"
  14 #include "mds_client.h"
  15
  16 #include <linux/ceph/ceph_features.h>
  17 #include <linux/ceph/messenger.h>
  18 #include <linux/ceph/decode.h>
  19 #include <linux/ceph/pagelist.h>
  20 #include <linux/ceph/auth.h>
  21 #include <linux/ceph/debugfs.h>
  22
  23 #define RECONNECT_MAX_SIZE (INT_MAX - PAGE_SIZE)
  24
  25 /*
  26  * A cluster of MDS (metadata server) daemons is responsible for
  27  * managing the file system namespace (the directory hierarchy and
  28  * inodes) and for coordinating shared access to storage.  Metadata is
  29  * partitioning hierarchically across a number of servers, and that
  30  * partition varies over time as the cluster adjusts the distribution
  31  * in order to balance load.
  32  *
  33  * The MDS client is primarily responsible to managing synchronous
  34  * metadata requests for operations like open, unlink, and so forth.
  35  * If there is a MDS failure, we find out about it when we (possibly
  36  * request and) receive a new MDS map, and can resubmit affected
  37  * requests.
  38  *
  39  * For the most part, though, we take advantage of a lossless
  40  * communications channel to the MDS, and do not need to worry about
  41  * timing out or resubmitting requests.
  42  *
  43  * We maintain a stateful "session" with each MDS we interact with.
  44  * Within each session, we sent periodic heartbeat messages to ensure
  45  * any capabilities or leases we have been issues remain valid.  If
  46  * the session times out and goes stale, our leases and capabilities
  47  * are no longer valid.
  48  */
  49
  50 struct ceph_reconnect_state {
  51         struct ceph_mds_session *session;
  52         int nr_caps, nr_realms;
  53         struct ceph_pagelist *pagelist;
  54         unsigned msg_version;
  55         bool allow_multi;
  56 };
  57
  58 static void __wake_requests(struct ceph_mds_client *mdsc,
  59                             struct list_head *head);
  60
  61 static const struct ceph_connection_operations mds_con_ops;
  62
  63
  64 /*
  65  * mds reply parsing
  66  */
  67
  68 /*
  69  * parse individual inode info
  70  */
  71 static int parse_reply_info_in(void **p, void *end,
  72                                struct ceph_mds_reply_info_in *info,
  73                                u64 features)
  74 {
  75         int err = -EIO;
  76
  77         info->in = *p;
  78         *p += sizeof(struct ceph_mds_reply_inode) +
  79                 sizeof(*info->in->fragtree.splits) *
  80                 le32_to_cpu(info->in->fragtree.nsplits);
  81
  82         ceph_decode_32_safe(p, end, info->symlink_len, bad);
  83         ceph_decode_need(p, end, info->symlink_len, bad);
  84         info->symlink = *p;
  85         *p += info->symlink_len;
  86
  87         ceph_decode_copy_safe(p, end, &info->dir_layout,
  88                               sizeof(info->dir_layout), bad);
  89         ceph_decode_32_safe(p, end, info->xattr_len, bad);
  90         ceph_decode_need(p, end, info->xattr_len, bad);
  91         info->xattr_data = *p;
  92         *p += info->xattr_len;
  93
  94         if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
  95                 ceph_decode_64_safe(p, end, info->inline_version, bad);
  96                 ceph_decode_32_safe(p, end, info->inline_len, bad);
  97                 ceph_decode_need(p, end, info->inline_len, bad);
  98                 info->inline_data = *p;
  99                 *p += info->inline_len;
 100         } else
 101                 info->inline_version = CEPH_INLINE_NONE;
 102
 103         if (features & CEPH_FEATURE_MDS_QUOTA) {
 104                 u8 struct_v, struct_compat;
 105                 u32 struct_len;
 106
 107                 /*
 108                  * both struct_v and struct_compat are expected to be >= 1
 109                  */
 110                 ceph_decode_8_safe(p, end, struct_v, bad);
 111                 ceph_decode_8_safe(p, end, struct_compat, bad);
 112                 if (!struct_v || !struct_compat)
 113                         goto bad;
 114                 ceph_decode_32_safe(p, end, struct_len, bad);
 115                 ceph_decode_need(p, end, struct_len, bad);
 116                 ceph_decode_64_safe(p, end, info->max_bytes, bad);
 117                 ceph_decode_64_safe(p, end, info->max_files, bad);
 118         } else {
 119                 info->max_bytes = 0;
 120                 info->max_files = 0;
 121         }
 122
 123         info->pool_ns_len = 0;
 124         info->pool_ns_data = NULL;
 125         if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 126                 ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 127                 if (info->pool_ns_len > 0) {
 128                         ceph_decode_need(p, end, info->pool_ns_len, bad);
 129                         info->pool_ns_data = *p;
 130                         *p += info->pool_ns_len;
 131                 }
 132         }
 133
 134         return 0;
 135 bad:
 136         return err;
 137 }
 138
 139 /*
 140  * parse a normal reply, which may contain a (dir+)dentry and/or a
 141  * target inode.
 142  */
 143 static int parse_reply_info_trace(void **p, void *end,
 144                                   struct ceph_mds_reply_info_parsed *info,
 145                                   u64 features)
 146 {
 147         int err;
 148
 149         if (info->head->is_dentry) {
 150                 err = parse_reply_info_in(p, end, &info->diri, features);
 151                 if (err < 0)
 152                         goto out_bad;
 153
 154                 if (unlikely(*p + sizeof(*info->dirfrag) > end))
 155                         goto bad;
 156                 info->dirfrag = *p;
 157                 *p += sizeof(*info->dirfrag) +
 158                         sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 159                 if (unlikely(*p > end))
 160                         goto bad;
 161
 162                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 163                 ceph_decode_need(p, end, info->dname_len, bad);
 164                 info->dname = *p;
 165                 *p += info->dname_len;
 166                 info->dlease = *p;
 167                 *p += sizeof(*info->dlease);
 168         }
 169
 170         if (info->head->is_target) {
 171                 err = parse_reply_info_in(p, end, &info->targeti, features);
 172                 if (err < 0)
 173                         goto out_bad;
 174         }
 175
 176         if (unlikely(*p != end))
 177                 goto bad;
 178         return 0;
 179
 180 bad:
 181         err = -EIO;
 182 out_bad:
 183         pr_err("problem parsing mds trace %d\n", err);
 184         return err;
 185 }
 186
 187 /*
 188  * parse readdir results
 189  */
 190 static int parse_reply_info_dir(void **p, void *end,
 191                                 struct ceph_mds_reply_info_parsed *info,
 192                                 u64 features)
 193 {
 194         u32 num, i = 0;
 195         int err;
 196
 197         info->dir_dir = *p;
 198         if (*p + sizeof(*info->dir_dir) > end)
 199                 goto bad;
 200         *p += sizeof(*info->dir_dir) +
 201                 sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 202         if (*p > end)
 203                 goto bad;
 204
 205         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 206         num = ceph_decode_32(p);
 207         {
 208                 u16 flags = ceph_decode_16(p);
 209                 info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 210                 info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 211                 info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 212                 info->offset_hash = !!(flags & CEPH_READDIR_OFFSET_HASH);
 213         }
 214         if (num == 0)
 215                 goto done;
 216
 217         BUG_ON(!info->dir_entries);
 218         if ((unsigned long)(info->dir_entries + num) >
 219             (unsigned long)info->dir_entries + info->dir_buf_size) {
 220                 pr_err("dir contents are larger than expected\n");
 221                 WARN_ON(1);
 222                 goto bad;
 223         }
 224
 225         info->dir_nr = num;
 226         while (num) {
 227                 struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 228                 /* dentry */
 229                 ceph_decode_need(p, end, sizeof(u32)*2, bad);
 230                 rde->name_len = ceph_decode_32(p);
 231                 ceph_decode_need(p, end, rde->name_len, bad);
 232                 rde->name = *p;
 233                 *p += rde->name_len;
 234                 dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 235                 rde->lease = *p;
 236                 *p += sizeof(struct ceph_mds_reply_lease);
 237
 238                 /* inode */
 239                 err = parse_reply_info_in(p, end, &rde->inode, features);
 240                 if (err < 0)
 241                         goto out_bad;
 242                 /* ceph_readdir_prepopulate() will update it */
 243                 rde->offset = 0;
 244                 i++;
 245                 num--;
 246         }
 247
 248 done:
 249         if (*p != end)
 250                 goto bad;
 251         return 0;
 252
 253 bad:
 254         err = -EIO;
 255 out_bad:
 256         pr_err("problem parsing dir contents %d\n", err);
 257         return err;
 258 }
 259
 260 /*
 261  * parse fcntl F_GETLK results
 262  */
 263 static int parse_reply_info_filelock(void **p, void *end,
 264                                      struct ceph_mds_reply_info_parsed *info,
 265                                      u64 features)
 266 {
 267         if (*p + sizeof(*info->filelock_reply) > end)
 268                 goto bad;
 269
 270         info->filelock_reply = *p;
 271         *p += sizeof(*info->filelock_reply);
 272
 273         if (unlikely(*p != end))
 274                 goto bad;
 275         return 0;
 276
 277 bad:
 278         return -EIO;
 279 }
 280
 281 /*
 282  * parse create results
 283  */
 284 static int parse_reply_info_create(void **p, void *end,
 285                                   struct ceph_mds_reply_info_parsed *info,
 286                                   u64 features)
 287 {
 288         if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 289                 if (*p == end) {
 290                         info->has_create_ino = false;
 291                 } else {
 292                         info->has_create_ino = true;
 293                         info->ino = ceph_decode_64(p);
 294                 }
 295         }
 296
 297         if (unlikely(*p != end))
 298                 goto bad;
 299         return 0;
 300
 301 bad:
 302         return -EIO;
 303 }
 304
 305 /*
 306  * parse extra results
 307  */
 308 static int parse_reply_info_extra(void **p, void *end,
 309                                   struct ceph_mds_reply_info_parsed *info,
 310                                   u64 features)
 311 {
 312         u32 op = le32_to_cpu(info->head->op);
 313
 314         if (op == CEPH_MDS_OP_GETFILELOCK)
 315                 return parse_reply_info_filelock(p, end, info, features);
 316         else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 317                 return parse_reply_info_dir(p, end, info, features);
 318         else if (op == CEPH_MDS_OP_CREATE)
 319                 return parse_reply_info_create(p, end, info, features);
 320         else
 321                 return -EIO;
 322 }
 323
 324 /*
 325  * parse entire mds reply
 326  */
 327 static int parse_reply_info(struct ceph_msg *msg,
 328                             struct ceph_mds_reply_info_parsed *info,
 329                             u64 features)
 330 {
 331         void *p, *end;
 332         u32 len;
 333         int err;
 334
 335         info->head = msg->front.iov_base;
 336         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 337         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 338
 339         /* trace */
 340         ceph_decode_32_safe(&p, end, len, bad);
 341         if (len > 0) {
 342                 ceph_decode_need(&p, end, len, bad);
 343                 err = parse_reply_info_trace(&p, p+len, info, features);
 344                 if (err < 0)
 345                         goto out_bad;
 346         }
 347
 348         /* extra */
 349         ceph_decode_32_safe(&p, end, len, bad);
 350         if (len > 0) {
 351                 ceph_decode_need(&p, end, len, bad);
 352                 err = parse_reply_info_extra(&p, p+len, info, features);
 353                 if (err < 0)
 354                         goto out_bad;
 355         }
 356
 357         /* snap blob */
 358         ceph_decode_32_safe(&p, end, len, bad);
 359         info->snapblob_len = len;
 360         info->snapblob = p;
 361         p += len;
 362
 363         if (p != end)
 364                 goto bad;
 365         return 0;
 366
 367 bad:
 368         err = -EIO;
 369 out_bad:
 370         pr_err("mds parse_reply err %d\n", err);
 371         return err;
 372 }
 373
 374 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 375 {
 376         if (!info->dir_entries)
 377                 return;
 378         free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 379 }
 380
 381
 382 /*
 383  * sessions
 384  */
 385 const char *ceph_session_state_name(int s)
 386 {
 387         switch (s) {
 388         case CEPH_MDS_SESSION_NEW: return "new";
 389         case CEPH_MDS_SESSION_OPENING: return "opening";
 390         case CEPH_MDS_SESSION_OPEN: return "open";
 391         case CEPH_MDS_SESSION_HUNG: return "hung";
 392         case CEPH_MDS_SESSION_CLOSING: return "closing";
 393         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 394         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 395         case CEPH_MDS_SESSION_REJECTED: return "rejected";
 396         default: return "???";
 397         }
 398 }
 399
 400 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 401 {
 402         if (refcount_inc_not_zero(&s->s_ref)) {
 403                 dout("mdsc get_session %p %d -> %d\n", s,
 404                      refcount_read(&s->s_ref)-1, refcount_read(&s->s_ref));
 405                 return s;
 406         } else {
 407                 dout("mdsc get_session %p 0 -- FAIL\n", s);
 408                 return NULL;
 409         }
 410 }
 411
 412 void ceph_put_mds_session(struct ceph_mds_session *s)
 413 {
 414         dout("mdsc put_session %p %d -> %d\n", s,
 415              refcount_read(&s->s_ref), refcount_read(&s->s_ref)-1);
 416         if (refcount_dec_and_test(&s->s_ref)) {
 417                 if (s->s_auth.authorizer)
 418                         ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 419                 kfree(s);
 420         }
 421 }
 422
 423 /*
 424  * called under mdsc->mutex
 425  */
 426 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 427                                                    int mds)
 428 {
 429         struct ceph_mds_session *session;
 430
 431         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 432                 return NULL;
 433         session = mdsc->sessions[mds];
 434         dout("lookup_mds_session %p %d\n", session,
 435              refcount_read(&session->s_ref));
 436         get_session(session);
 437         return session;
 438 }
 439
 440 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 441 {
 442         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 443                 return false;
 444         else
 445                 return true;
 446 }
 447
 448 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 449                                        struct ceph_mds_session *s)
 450 {
 451         if (s->s_mds >= mdsc->max_sessions ||
 452             mdsc->sessions[s->s_mds] != s)
 453                 return -ENOENT;
 454         return 0;
 455 }
 456
 457 /*
 458  * create+register a new session for given mds.
 459  * called under mdsc->mutex.
 460  */
 461 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 462                                                  int mds)
 463 {
 464         struct ceph_mds_session *s;
 465
 466         if (mds >= mdsc->mdsmap->m_num_mds)
 467                 return ERR_PTR(-EINVAL);
 468
 469         s = kzalloc(sizeof(*s), GFP_NOFS);
 470         if (!s)
 471                 return ERR_PTR(-ENOMEM);
 472
 473         if (mds >= mdsc->max_sessions) {
 474                 int newmax = 1 << get_count_order(mds + 1);
 475                 struct ceph_mds_session **sa;
 476
 477                 dout("%s: realloc to %d\n", __func__, newmax);
 478                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 479                 if (!sa)
 480                         goto fail_realloc;
 481                 if (mdsc->sessions) {
 482                         memcpy(sa, mdsc->sessions,
 483                                mdsc->max_sessions * sizeof(void *));
 484                         kfree(mdsc->sessions);
 485                 }
 486                 mdsc->sessions = sa;
 487                 mdsc->max_sessions = newmax;
 488         }
 489
 490         dout("%s: mds%d\n", __func__, mds);
 491         s->s_mdsc = mdsc;
 492         s->s_mds = mds;
 493         s->s_state = CEPH_MDS_SESSION_NEW;
 494         s->s_ttl = 0;
 495         s->s_seq = 0;
 496         mutex_init(&s->s_mutex);
 497
 498         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 499
 500         spin_lock_init(&s->s_gen_ttl_lock);
 501         s->s_cap_gen = 0;
 502         s->s_cap_ttl = jiffies - 1;
 503
 504         spin_lock_init(&s->s_cap_lock);
 505         s->s_renew_requested = 0;
 506         s->s_renew_seq = 0;
 507         INIT_LIST_HEAD(&s->s_caps);
 508         s->s_nr_caps = 0;
 509         s->s_trim_caps = 0;
 510         refcount_set(&s->s_ref, 1);
 511         INIT_LIST_HEAD(&s->s_waiting);
 512         INIT_LIST_HEAD(&s->s_unsafe);
 513         s->s_num_cap_releases = 0;
 514         s->s_cap_reconnect = 0;
 515         s->s_cap_iterator = NULL;
 516         INIT_LIST_HEAD(&s->s_cap_releases);
 517         INIT_LIST_HEAD(&s->s_cap_flushing);
 518
 519         mdsc->sessions[mds] = s;
 520         atomic_inc(&mdsc->num_sessions);
 521         refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 522
 523         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 524                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 525
 526         return s;
 527
 528 fail_realloc:
 529         kfree(s);
 530         return ERR_PTR(-ENOMEM);
 531 }
 532
 533 /*
 534  * called under mdsc->mutex
 535  */
 536 static void __unregister_session(struct ceph_mds_client *mdsc,
 537                                struct ceph_mds_session *s)
 538 {
 539         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 540         BUG_ON(mdsc->sessions[s->s_mds] != s);
 541         mdsc->sessions[s->s_mds] = NULL;
 542         ceph_con_close(&s->s_con);
 543         ceph_put_mds_session(s);
 544         atomic_dec(&mdsc->num_sessions);
 545 }
 546
 547 /*
 548  * drop session refs in request.
 549  *
 550  * should be last request ref, or hold mdsc->mutex
 551  */
 552 static void put_request_session(struct ceph_mds_request *req)
 553 {
 554         if (req->r_session) {
 555                 ceph_put_mds_session(req->r_session);
 556                 req->r_session = NULL;
 557         }
 558 }
 559
 560 void ceph_mdsc_release_request(struct kref *kref)
 561 {
 562         struct ceph_mds_request *req = container_of(kref,
 563                                                     struct ceph_mds_request,
 564                                                     r_kref);
 565         destroy_reply_info(&req->r_reply_info);
 566         if (req->r_request)
 567                 ceph_msg_put(req->r_request);
 568         if (req->r_reply)
 569                 ceph_msg_put(req->r_reply);
 570         if (req->r_inode) {
 571                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 572                 iput(req->r_inode);
 573         }
 574         if (req->r_parent)
 575                 ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
 576         iput(req->r_target_inode);
 577         if (req->r_dentry)
 578                 dput(req->r_dentry);
 579         if (req->r_old_dentry)
 580                 dput(req->r_old_dentry);
 581         if (req->r_old_dentry_dir) {
 582                 /*
 583                  * track (and drop pins for) r_old_dentry_dir
 584                  * separately, since r_old_dentry's d_parent may have
 585                  * changed between the dir mutex being dropped and
 586                  * this request being freed.
 587                  */
 588                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 589                                   CEPH_CAP_PIN);
 590                 iput(req->r_old_dentry_dir);
 591         }
 592         kfree(req->r_path1);
 593         kfree(req->r_path2);
 594         if (req->r_pagelist)
 595                 ceph_pagelist_release(req->r_pagelist);
 596         put_request_session(req);
 597         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 598         kfree(req);
 599 }
 600
 601 DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 602
 603 /*
 604  * lookup session, bump ref if found.
 605  *
 606  * called under mdsc->mutex.
 607  */
 608 static struct ceph_mds_request *
 609 lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 610 {
 611         struct ceph_mds_request *req;
 612
 613         req = lookup_request(&mdsc->request_tree, tid);
 614         if (req)
 615                 ceph_mdsc_get_request(req);
 616
 617         return req;
 618 }
 619
 620 /*
 621  * Register an in-flight request, and assign a tid.  Link to directory
 622  * are modifying (if any).
 623  *
 624  * Called under mdsc->mutex.
 625  */
 626 static void __register_request(struct ceph_mds_client *mdsc,
 627                                struct ceph_mds_request *req,
 628                                struct inode *dir)
 629 {
 630         int ret = 0;
 631
 632         req->r_tid = ++mdsc->last_tid;
 633         if (req->r_num_caps) {
 634                 ret = ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 635                                         req->r_num_caps);
 636                 if (ret < 0) {
 637                         pr_err("__register_request %p "
 638                                "failed to reserve caps: %d\n", req, ret);
 639                         /* set req->r_err to fail early from __do_request */
 640                         req->r_err = ret;
 641                         return;
 642                 }
 643         }
 644         dout("__register_request %p tid %lld\n", req, req->r_tid);
 645         ceph_mdsc_get_request(req);
 646         insert_request(&mdsc->request_tree, req);
 647
 648         req->r_uid = current_fsuid();
 649         req->r_gid = current_fsgid();
 650
 651         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 652                 mdsc->oldest_tid = req->r_tid;
 653
 654         if (dir) {
 655                 ihold(dir);
 656                 req->r_unsafe_dir = dir;
 657         }
 658 }
 659
 660 static void __unregister_request(struct ceph_mds_client *mdsc,
 661                                  struct ceph_mds_request *req)
 662 {
 663         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 664
 665         /* Never leave an unregistered request on an unsafe list! */
 666         list_del_init(&req->r_unsafe_item);
 667
 668         if (req->r_tid == mdsc->oldest_tid) {
 669                 struct rb_node *p = rb_next(&req->r_node);
 670                 mdsc->oldest_tid = 0;
 671                 while (p) {
 672                         struct ceph_mds_request *next_req =
 673                                 rb_entry(p, struct ceph_mds_request, r_node);
 674                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 675                                 mdsc->oldest_tid = next_req->r_tid;
 676                                 break;
 677                         }
 678                         p = rb_next(p);
 679                 }
 680         }
 681
 682         erase_request(&mdsc->request_tree, req);
 683
 684         if (req->r_unsafe_dir  &&
 685             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 686                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 687                 spin_lock(&ci->i_unsafe_lock);
 688                 list_del_init(&req->r_unsafe_dir_item);
 689                 spin_unlock(&ci->i_unsafe_lock);
 690         }
 691         if (req->r_target_inode &&
 692             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 693                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 694                 spin_lock(&ci->i_unsafe_lock);
 695                 list_del_init(&req->r_unsafe_target_item);
 696                 spin_unlock(&ci->i_unsafe_lock);
 697         }
 698
 699         if (req->r_unsafe_dir) {
 700                 iput(req->r_unsafe_dir);
 701                 req->r_unsafe_dir = NULL;
 702         }
 703
 704         complete_all(&req->r_safe_completion);
 705
 706         ceph_mdsc_put_request(req);
 707 }
 708
 709 /*
 710  * Walk back up the dentry tree until we hit a dentry representing a
 711  * non-snapshot inode. We do this using the rcu_read_lock (which must be held
 712  * when calling this) to ensure that the objects won't disappear while we're
 713  * working with them. Once we hit a candidate dentry, we attempt to take a
 714  * reference to it, and return that as the result.
 715  */
 716 static struct inode *get_nonsnap_parent(struct dentry *dentry)
 717 {
 718         struct inode *inode = NULL;
 719
 720         while (dentry && !IS_ROOT(dentry)) {
 721                 inode = d_inode_rcu(dentry);
 722                 if (!inode || ceph_snap(inode) == CEPH_NOSNAP)
 723                         break;
 724                 dentry = dentry->d_parent;
 725         }
 726         if (inode)
 727                 inode = igrab(inode);
 728         return inode;
 729 }
 730
 731 /*
 732  * Choose mds to send request to next.  If there is a hint set in the
 733  * request (e.g., due to a prior forward hint from the mds), use that.
 734  * Otherwise, consult frag tree and/or caps to identify the
 735  * appropriate mds.  If all else fails, choose randomly.
 736  *
 737  * Called under mdsc->mutex.
 738  */
 739 static int __choose_mds(struct ceph_mds_client *mdsc,
 740                         struct ceph_mds_request *req)
 741 {
 742         struct inode *inode;
 743         struct ceph_inode_info *ci;
 744         struct ceph_cap *cap;
 745         int mode = req->r_direct_mode;
 746         int mds = -1;
 747         u32 hash = req->r_direct_hash;
 748         bool is_hash = test_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
 749
 750         /*
 751          * is there a specific mds we should try?  ignore hint if we have
 752          * no session and the mds is not up (active or recovering).
 753          */
 754         if (req->r_resend_mds >= 0 &&
 755             (__have_session(mdsc, req->r_resend_mds) ||
 756              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 757                 dout("choose_mds using resend_mds mds%d\n",
 758                      req->r_resend_mds);
 759                 return req->r_resend_mds;
 760         }
 761
 762         if (mode == USE_RANDOM_MDS)
 763                 goto random;
 764
 765         inode = NULL;
 766         if (req->r_inode) {
 767                 if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
 768                         inode = req->r_inode;
 769                         ihold(inode);
 770                 } else {
 771                         /* req->r_dentry is non-null for LSSNAP request */
 772                         rcu_read_lock();
 773                         inode = get_nonsnap_parent(req->r_dentry);
 774                         rcu_read_unlock();
 775                         dout("__choose_mds using snapdir's parent %p\n", inode);
 776                 }
 777         } else if (req->r_dentry) {
 778                 /* ignore race with rename; old or new d_parent is okay */
 779                 struct dentry *parent;
 780                 struct inode *dir;
 781
 782                 rcu_read_lock();
 783                 parent = req->r_dentry->d_parent;
 784                 dir = req->r_parent ? : d_inode_rcu(parent);
 785
 786                 if (!dir || dir->i_sb != mdsc->fsc->sb) {
 787                         /*  not this fs or parent went negative */
 788                         inode = d_inode(req->r_dentry);
 789                         if (inode)
 790                                 ihold(inode);
 791                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 792                         /* direct snapped/virtual snapdir requests
 793                          * based on parent dir inode */
 794                         inode = get_nonsnap_parent(parent);
 795                         dout("__choose_mds using nonsnap parent %p\n", inode);
 796                 } else {
 797                         /* dentry target */
 798                         inode = d_inode(req->r_dentry);
 799                         if (!inode || mode == USE_AUTH_MDS) {
 800                                 /* dir + name */
 801                                 inode = igrab(dir);
 802                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 803                                 is_hash = true;
 804                         } else {
 805                                 ihold(inode);
 806                         }
 807                 }
 808                 rcu_read_unlock();
 809         }
 810
 811         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 812              (int)hash, mode);
 813         if (!inode)
 814                 goto random;
 815         ci = ceph_inode(inode);
 816
 817         if (is_hash && S_ISDIR(inode->i_mode)) {
 818                 struct ceph_inode_frag frag;
 819                 int found;
 820
 821                 ceph_choose_frag(ci, hash, &frag, &found);
 822                 if (found) {
 823                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 824                                 u8 r;
 825
 826                                 /* choose a random replica */
 827                                 get_random_bytes(&r, 1);
 828                                 r %= frag.ndist;
 829                                 mds = frag.dist[r];
 830                                 dout("choose_mds %p %llx.%llx "
 831                                      "frag %u mds%d (%d/%d)\n",
 832                                      inode, ceph_vinop(inode),
 833                                      frag.frag, mds,
 834                                      (int)r, frag.ndist);
 835                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 836                                     CEPH_MDS_STATE_ACTIVE)
 837                                         goto out;
 838                         }
 839
 840                         /* since this file/dir wasn't known to be
 841                          * replicated, then we want to look for the
 842                          * authoritative mds. */
 843                         mode = USE_AUTH_MDS;
 844                         if (frag.mds >= 0) {
 845                                 /* choose auth mds */
 846                                 mds = frag.mds;
 847                                 dout("choose_mds %p %llx.%llx "
 848                                      "frag %u mds%d (auth)\n",
 849                                      inode, ceph_vinop(inode), frag.frag, mds);
 850                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 851                                     CEPH_MDS_STATE_ACTIVE)
 852                                         goto out;
 853                         }
 854                 }
 855         }
 856
 857         spin_lock(&ci->i_ceph_lock);
 858         cap = NULL;
 859         if (mode == USE_AUTH_MDS)
 860                 cap = ci->i_auth_cap;
 861         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 862                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 863         if (!cap) {
 864                 spin_unlock(&ci->i_ceph_lock);
 865                 iput(inode);
 866                 goto random;
 867         }
 868         mds = cap->session->s_mds;
 869         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 870              inode, ceph_vinop(inode), mds,
 871              cap == ci->i_auth_cap ? "auth " : "", cap);
 872         spin_unlock(&ci->i_ceph_lock);
 873 out:
 874         iput(inode);
 875         return mds;
 876
 877 random:
 878         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 879         dout("choose_mds chose random mds%d\n", mds);
 880         return mds;
 881 }
 882
 883
 884 /*
 885  * session messages
 886  */
 887 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 888 {
 889         struct ceph_msg *msg;
 890         struct ceph_mds_session_head *h;
 891
 892         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 893                            false);
 894         if (!msg) {
 895                 pr_err("create_session_msg ENOMEM creating msg\n");
 896                 return NULL;
 897         }
 898         h = msg->front.iov_base;
 899         h->op = cpu_to_le32(op);
 900         h->seq = cpu_to_le64(seq);
 901
 902         return msg;
 903 }
 904
 905 static void encode_supported_features(void **p, void *end)
 906 {
 907         static const unsigned char bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
 908         static const size_t count = ARRAY_SIZE(bits);
 909
 910         if (count > 0) {
 911                 size_t i;
 912                 size_t size = ((size_t)bits[count - 1] + 64) / 64 * 8;
 913
 914                 BUG_ON(*p + 4 + size > end);
 915                 ceph_encode_32(p, size);
 916                 memset(*p, 0, size);
 917                 for (i = 0; i < count; i++)
 918                         ((unsigned char*)(*p))[i / 8] |= 1 << (bits[i] % 8);
 919                 *p += size;
 920         } else {
 921                 BUG_ON(*p + 4 > end);
 922                 ceph_encode_32(p, 0);
 923         }
 924 }
 925
 926 /*
 927  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
 928  * to include additional client metadata fields.
 929  */
 930 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
 931 {
 932         struct ceph_msg *msg;
 933         struct ceph_mds_session_head *h;
 934         int i = -1;
 935         int extra_bytes = 0;
 936         int metadata_key_count = 0;
 937         struct ceph_options *opt = mdsc->fsc->client->options;
 938         struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
 939         void *p, *end;
 940
 941         const char* metadata[][2] = {
 942                 {"hostname", mdsc->nodename},
 943                 {"kernel_version", init_utsname()->release},
 944                 {"entity_id", opt->name ? : ""},
 945                 {"root", fsopt->server_path ? : "/"},
 946                 {NULL, NULL}
 947         };
 948
 949         /* Calculate serialized length of metadata */
 950         extra_bytes = 4;  /* map length */
 951         for (i = 0; metadata[i][0]; ++i) {
 952                 extra_bytes += 8 + strlen(metadata[i][0]) +
 953                         strlen(metadata[i][1]);
 954                 metadata_key_count++;
 955         }
 956         /* supported feature */
 957         extra_bytes += 4 + 8;
 958
 959         /* Allocate the message */
 960         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + extra_bytes,
 961                            GFP_NOFS, false);
 962         if (!msg) {
 963                 pr_err("create_session_msg ENOMEM creating msg\n");
 964                 return NULL;
 965         }
 966         p = msg->front.iov_base;
 967         end = p + msg->front.iov_len;
 968
 969         h = p;
 970         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
 971         h->seq = cpu_to_le64(seq);
 972
 973         /*
 974          * Serialize client metadata into waiting buffer space, using
 975          * the format that userspace expects for map<string, string>
 976          *
 977          * ClientSession messages with metadata are v2
 978          */
 979         msg->hdr.version = cpu_to_le16(3);
 980         msg->hdr.compat_version = cpu_to_le16(1);
 981
 982         /* The write pointer, following the session_head structure */
 983         p += sizeof(*h);
 984
 985         /* Number of entries in the map */
 986         ceph_encode_32(&p, metadata_key_count);
 987
 988         /* Two length-prefixed strings for each entry in the map */
 989         for (i = 0; metadata[i][0]; ++i) {
 990                 size_t const key_len = strlen(metadata[i][0]);
 991                 size_t const val_len = strlen(metadata[i][1]);
 992
 993                 ceph_encode_32(&p, key_len);
 994                 memcpy(p, metadata[i][0], key_len);
 995                 p += key_len;
 996                 ceph_encode_32(&p, val_len);
 997                 memcpy(p, metadata[i][1], val_len);
 998                 p += val_len;
 999         }
1000
1001         encode_supported_features(&p, end);
1002         msg->front.iov_len = p - msg->front.iov_base;
1003         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1004
1005         return msg;
1006 }
1007
1008 /*
1009  * send session open request.
1010  *
1011  * called under mdsc->mutex
1012  */
1013 static int __open_session(struct ceph_mds_client *mdsc,
1014                           struct ceph_mds_session *session)
1015 {
1016         struct ceph_msg *msg;
1017         int mstate;
1018         int mds = session->s_mds;
1019
1020         /* wait for mds to go active? */
1021         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
1022         dout("open_session to mds%d (%s)\n", mds,
1023              ceph_mds_state_name(mstate));
1024         session->s_state = CEPH_MDS_SESSION_OPENING;
1025         session->s_renew_requested = jiffies;
1026
1027         /* send connect message */
1028         msg = create_session_open_msg(mdsc, session->s_seq);
1029         if (!msg)
1030                 return -ENOMEM;
1031         ceph_con_send(&session->s_con, msg);
1032         return 0;
1033 }
1034
1035 /*
1036  * open sessions for any export targets for the given mds
1037  *
1038  * called under mdsc->mutex
1039  */
1040 static struct ceph_mds_session *
1041 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
1042 {
1043         struct ceph_mds_session *session;
1044
1045         session = __ceph_lookup_mds_session(mdsc, target);
1046         if (!session) {
1047                 session = register_session(mdsc, target);
1048                 if (IS_ERR(session))
1049                         return session;
1050         }
1051         if (session->s_state == CEPH_MDS_SESSION_NEW ||
1052             session->s_state == CEPH_MDS_SESSION_CLOSING)
1053                 __open_session(mdsc, session);
1054
1055         return session;
1056 }
1057
1058 struct ceph_mds_session *
1059 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
1060 {
1061         struct ceph_mds_session *session;
1062
1063         dout("open_export_target_session to mds%d\n", target);
1064
1065         mutex_lock(&mdsc->mutex);
1066         session = __open_export_target_session(mdsc, target);
1067         mutex_unlock(&mdsc->mutex);
1068
1069         return session;
1070 }
1071
1072 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
1073                                           struct ceph_mds_session *session)
1074 {
1075         struct ceph_mds_info *mi;
1076         struct ceph_mds_session *ts;
1077         int i, mds = session->s_mds;
1078
1079         if (mds >= mdsc->mdsmap->m_num_mds)
1080                 return;
1081
1082         mi = &mdsc->mdsmap->m_info[mds];
1083         dout("open_export_target_sessions for mds%d (%d targets)\n",
1084              session->s_mds, mi->num_export_targets);
1085
1086         for (i = 0; i < mi->num_export_targets; i++) {
1087                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1088                 if (!IS_ERR(ts))
1089                         ceph_put_mds_session(ts);
1090         }
1091 }
1092
1093 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1094                                            struct ceph_mds_session *session)
1095 {
1096         mutex_lock(&mdsc->mutex);
1097         __open_export_target_sessions(mdsc, session);
1098         mutex_unlock(&mdsc->mutex);
1099 }
1100
1101 /*
1102  * session caps
1103  */
1104
1105 static void detach_cap_releases(struct ceph_mds_session *session,
1106                                 struct list_head *target)
1107 {
1108         lockdep_assert_held(&session->s_cap_lock);
1109
1110         list_splice_init(&session->s_cap_releases, target);
1111         session->s_num_cap_releases = 0;
1112         dout("dispose_cap_releases mds%d\n", session->s_mds);
1113 }
1114
1115 static void dispose_cap_releases(struct ceph_mds_client *mdsc,
1116                                  struct list_head *dispose)
1117 {
1118         while (!list_empty(dispose)) {
1119                 struct ceph_cap *cap;
1120                 /* zero out the in-progress message */
1121                 cap = list_first_entry(dispose, struct ceph_cap, session_caps);
1122                 list_del(&cap->session_caps);
1123                 ceph_put_cap(mdsc, cap);
1124         }
1125 }
1126
1127 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1128                                      struct ceph_mds_session *session)
1129 {
1130         struct ceph_mds_request *req;
1131         struct rb_node *p;
1132
1133         dout("cleanup_session_requests mds%d\n", session->s_mds);
1134         mutex_lock(&mdsc->mutex);
1135         while (!list_empty(&session->s_unsafe)) {
1136                 req = list_first_entry(&session->s_unsafe,
1137                                        struct ceph_mds_request, r_unsafe_item);
1138                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1139                                     req->r_tid);
1140                 __unregister_request(mdsc, req);
1141         }
1142         /* zero r_attempts, so kick_requests() will re-send requests */
1143         p = rb_first(&mdsc->request_tree);
1144         while (p) {
1145                 req = rb_entry(p, struct ceph_mds_request, r_node);
1146                 p = rb_next(p);
1147                 if (req->r_session &&
1148                     req->r_session->s_mds == session->s_mds)
1149                         req->r_attempts = 0;
1150         }
1151         mutex_unlock(&mdsc->mutex);
1152 }
1153
1154 /*
1155  * Helper to safely iterate over all caps associated with a session, with
1156  * special care taken to handle a racing __ceph_remove_cap().
1157  *
1158  * Caller must hold session s_mutex.
1159  */
1160 static int iterate_session_caps(struct ceph_mds_session *session,
1161                                  int (*cb)(struct inode *, struct ceph_cap *,
1162                                             void *), void *arg)
1163 {
1164         struct list_head *p;
1165         struct ceph_cap *cap;
1166         struct inode *inode, *last_inode = NULL;
1167         struct ceph_cap *old_cap = NULL;
1168         int ret;
1169
1170         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1171         spin_lock(&session->s_cap_lock);
1172         p = session->s_caps.next;
1173         while (p != &session->s_caps) {
1174                 cap = list_entry(p, struct ceph_cap, session_caps);
1175                 inode = igrab(&cap->ci->vfs_inode);
1176                 if (!inode) {
1177                         p = p->next;
1178                         continue;
1179                 }
1180                 session->s_cap_iterator = cap;
1181                 spin_unlock(&session->s_cap_lock);
1182
1183                 if (last_inode) {
1184                         iput(last_inode);
1185                         last_inode = NULL;
1186                 }
1187                 if (old_cap) {
1188                         ceph_put_cap(session->s_mdsc, old_cap);
1189                         old_cap = NULL;
1190                 }
1191
1192                 ret = cb(inode, cap, arg);
1193                 last_inode = inode;
1194
1195                 spin_lock(&session->s_cap_lock);
1196                 p = p->next;
1197                 if (!cap->ci) {
1198                         dout("iterate_session_caps  finishing cap %p removal\n",
1199                              cap);
1200                         BUG_ON(cap->session != session);
1201                         cap->session = NULL;
1202                         list_del_init(&cap->session_caps);
1203                         session->s_nr_caps--;
1204                         if (cap->queue_release) {
1205                                 list_add_tail(&cap->session_caps,
1206                                               &session->s_cap_releases);
1207                                 session->s_num_cap_releases++;
1208                         } else {
1209                                 old_cap = cap;  /* put_cap it w/o locks held */
1210                         }
1211                 }
1212                 if (ret < 0)
1213                         goto out;
1214         }
1215         ret = 0;
1216 out:
1217         session->s_cap_iterator = NULL;
1218         spin_unlock(&session->s_cap_lock);
1219
1220         iput(last_inode);
1221         if (old_cap)
1222                 ceph_put_cap(session->s_mdsc, old_cap);
1223
1224         return ret;
1225 }
1226
1227 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1228                                   void *arg)
1229 {
1230         struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1231         struct ceph_inode_info *ci = ceph_inode(inode);
1232         LIST_HEAD(to_remove);
1233         bool drop = false;
1234         bool invalidate = false;
1235
1236         dout("removing cap %p, ci is %p, inode is %p\n",
1237              cap, ci, &ci->vfs_inode);
1238         spin_lock(&ci->i_ceph_lock);
1239         if (cap->mds_wanted | cap->issued)
1240                 ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1241         __ceph_remove_cap(cap, false);
1242         if (!ci->i_auth_cap) {
1243                 struct ceph_cap_flush *cf;
1244                 struct ceph_mds_client *mdsc = fsc->mdsc;
1245
1246                 if (ci->i_wrbuffer_ref > 0 &&
1247                     READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
1248                         invalidate = true;
1249
1250                 while (!list_empty(&ci->i_cap_flush_list)) {
1251                         cf = list_first_entry(&ci->i_cap_flush_list,
1252                                               struct ceph_cap_flush, i_list);
1253                         list_move(&cf->i_list, &to_remove);
1254                 }
1255
1256                 spin_lock(&mdsc->cap_dirty_lock);
1257
1258                 list_for_each_entry(cf, &to_remove, i_list)
1259                         list_del(&cf->g_list);
1260
1261                 if (!list_empty(&ci->i_dirty_item)) {
1262                         pr_warn_ratelimited(
1263                                 " dropping dirty %s state for %p %lld\n",
1264                                 ceph_cap_string(ci->i_dirty_caps),
1265                                 inode, ceph_ino(inode));
1266                         ci->i_dirty_caps = 0;
1267                         list_del_init(&ci->i_dirty_item);
1268                         drop = true;
1269                 }
1270                 if (!list_empty(&ci->i_flushing_item)) {
1271                         pr_warn_ratelimited(
1272                                 " dropping dirty+flushing %s state for %p %lld\n",
1273                                 ceph_cap_string(ci->i_flushing_caps),
1274                                 inode, ceph_ino(inode));
1275                         ci->i_flushing_caps = 0;
1276                         list_del_init(&ci->i_flushing_item);
1277                         mdsc->num_cap_flushing--;
1278                         drop = true;
1279                 }
1280                 spin_unlock(&mdsc->cap_dirty_lock);
1281
1282                 if (atomic_read(&ci->i_filelock_ref) > 0) {
1283                         /* make further file lock syscall return -EIO */
1284                         ci->i_ceph_flags |= CEPH_I_ERROR_FILELOCK;
1285                         pr_warn_ratelimited(" dropping file locks for %p %lld\n",
1286                                             inode, ceph_ino(inode));
1287                 }
1288
1289                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1290                         list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
1291                         ci->i_prealloc_cap_flush = NULL;
1292                 }
1293         }
1294         spin_unlock(&ci->i_ceph_lock);
1295         while (!list_empty(&to_remove)) {
1296                 struct ceph_cap_flush *cf;
1297                 cf = list_first_entry(&to_remove,
1298                                       struct ceph_cap_flush, i_list);
1299                 list_del(&cf->i_list);
1300                 ceph_free_cap_flush(cf);
1301         }
1302
1303         wake_up_all(&ci->i_cap_wq);
1304         if (invalidate)
1305                 ceph_queue_invalidate(inode);
1306         if (drop)
1307                 iput(inode);
1308         return 0;
1309 }
1310
1311 /*
1312  * caller must hold session s_mutex
1313  */
1314 static void remove_session_caps(struct ceph_mds_session *session)
1315 {
1316         struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1317         struct super_block *sb = fsc->sb;
1318         LIST_HEAD(dispose);
1319
1320         dout("remove_session_caps on %p\n", session);
1321         iterate_session_caps(session, remove_session_caps_cb, fsc);
1322
1323         wake_up_all(&fsc->mdsc->cap_flushing_wq);
1324
1325         spin_lock(&session->s_cap_lock);
1326         if (session->s_nr_caps > 0) {
1327                 struct inode *inode;
1328                 struct ceph_cap *cap, *prev = NULL;
1329                 struct ceph_vino vino;
1330                 /*
1331                  * iterate_session_caps() skips inodes that are being
1332                  * deleted, we need to wait until deletions are complete.
1333                  * __wait_on_freeing_inode() is designed for the job,
1334                  * but it is not exported, so use lookup inode function
1335                  * to access it.
1336                  */
1337                 while (!list_empty(&session->s_caps)) {
1338                         cap = list_entry(session->s_caps.next,
1339                                          struct ceph_cap, session_caps);
1340                         if (cap == prev)
1341                                 break;
1342                         prev = cap;
1343                         vino = cap->ci->i_vino;
1344                         spin_unlock(&session->s_cap_lock);
1345
1346                         inode = ceph_find_inode(sb, vino);
1347                         iput(inode);
1348
1349                         spin_lock(&session->s_cap_lock);
1350                 }
1351         }
1352
1353         // drop cap expires and unlock s_cap_lock
1354         detach_cap_releases(session, &dispose);
1355
1356         BUG_ON(session->s_nr_caps > 0);
1357         BUG_ON(!list_empty(&session->s_cap_flushing));
1358         spin_unlock(&session->s_cap_lock);
1359         dispose_cap_releases(session->s_mdsc, &dispose);
1360 }
1361
1362 enum {
1363         RECONNECT,
1364         RENEWCAPS,
1365         FORCE_RO,
1366 };
1367
1368 /*
1369  * wake up any threads waiting on this session's caps.  if the cap is
1370  * old (didn't get renewed on the client reconnect), remove it now.
1371  *
1372  * caller must hold s_mutex.
1373  */
1374 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1375                               void *arg)
1376 {
1377         struct ceph_inode_info *ci = ceph_inode(inode);
1378         unsigned long ev = (unsigned long)arg;
1379
1380         if (ev == RECONNECT) {
1381                 spin_lock(&ci->i_ceph_lock);
1382                 ci->i_wanted_max_size = 0;
1383                 ci->i_requested_max_size = 0;
1384                 spin_unlock(&ci->i_ceph_lock);
1385         } else if (ev == RENEWCAPS) {
1386                 if (cap->cap_gen < cap->session->s_cap_gen) {
1387                         /* mds did not re-issue stale cap */
1388                         spin_lock(&ci->i_ceph_lock);
1389                         cap->issued = cap->implemented = CEPH_CAP_PIN;
1390                         /* make sure mds knows what we want */
1391                         if (__ceph_caps_file_wanted(ci) & ~cap->mds_wanted)
1392                                 ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1393                         spin_unlock(&ci->i_ceph_lock);
1394                 }
1395         } else if (ev == FORCE_RO) {
1396         }
1397         wake_up_all(&ci->i_cap_wq);
1398         return 0;
1399 }
1400
1401 static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
1402 {
1403         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1404         iterate_session_caps(session, wake_up_session_cb,
1405                              (void *)(unsigned long)ev);
1406 }
1407
1408 /*
1409  * Send periodic message to MDS renewing all currently held caps.  The
1410  * ack will reset the expiration for all caps from this session.
1411  *
1412  * caller holds s_mutex
1413  */
1414 static int send_renew_caps(struct ceph_mds_client *mdsc,
1415                            struct ceph_mds_session *session)
1416 {
1417         struct ceph_msg *msg;
1418         int state;
1419
1420         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1421             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1422                 pr_info("mds%d caps stale\n", session->s_mds);
1423         session->s_renew_requested = jiffies;
1424
1425         /* do not try to renew caps until a recovering mds has reconnected
1426          * with its clients. */
1427         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1428         if (state < CEPH_MDS_STATE_RECONNECT) {
1429                 dout("send_renew_caps ignoring mds%d (%s)\n",
1430                      session->s_mds, ceph_mds_state_name(state));
1431                 return 0;
1432         }
1433
1434         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1435                 ceph_mds_state_name(state));
1436         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1437                                  ++session->s_renew_seq);
1438         if (!msg)
1439                 return -ENOMEM;
1440         ceph_con_send(&session->s_con, msg);
1441         return 0;
1442 }
1443
1444 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1445                              struct ceph_mds_session *session, u64 seq)
1446 {
1447         struct ceph_msg *msg;
1448
1449         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1450              session->s_mds, ceph_session_state_name(session->s_state), seq);
1451         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1452         if (!msg)
1453                 return -ENOMEM;
1454         ceph_con_send(&session->s_con, msg);
1455         return 0;
1456 }
1457
1458
1459 /*
1460  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1461  *
1462  * Called under session->s_mutex
1463  */
1464 static void renewed_caps(struct ceph_mds_client *mdsc,
1465                          struct ceph_mds_session *session, int is_renew)
1466 {
1467         int was_stale;
1468         int wake = 0;
1469
1470         spin_lock(&session->s_cap_lock);
1471         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1472
1473         session->s_cap_ttl = session->s_renew_requested +
1474                 mdsc->mdsmap->m_session_timeout*HZ;
1475
1476         if (was_stale) {
1477                 if (time_before(jiffies, session->s_cap_ttl)) {
1478                         pr_info("mds%d caps renewed\n", session->s_mds);
1479                         wake = 1;
1480                 } else {
1481                         pr_info("mds%d caps still stale\n", session->s_mds);
1482                 }
1483         }
1484         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1485              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1486              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1487         spin_unlock(&session->s_cap_lock);
1488
1489         if (wake)
1490                 wake_up_session_caps(session, RENEWCAPS);
1491 }
1492
1493 /*
1494  * send a session close request
1495  */
1496 static int request_close_session(struct ceph_mds_client *mdsc,
1497                                  struct ceph_mds_session *session)
1498 {
1499         struct ceph_msg *msg;
1500
1501         dout("request_close_session mds%d state %s seq %lld\n",
1502              session->s_mds, ceph_session_state_name(session->s_state),
1503              session->s_seq);
1504         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1505         if (!msg)
1506                 return -ENOMEM;
1507         ceph_con_send(&session->s_con, msg);
1508         return 1;
1509 }
1510
1511 /*
1512  * Called with s_mutex held.
1513  */
1514 static int __close_session(struct ceph_mds_client *mdsc,
1515                          struct ceph_mds_session *session)
1516 {
1517         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1518                 return 0;
1519         session->s_state = CEPH_MDS_SESSION_CLOSING;
1520         return request_close_session(mdsc, session);
1521 }
1522
1523 static bool drop_negative_children(struct dentry *dentry)
1524 {
1525         struct dentry *child;
1526         bool all_negative = true;
1527
1528         if (!d_is_dir(dentry))
1529                 goto out;
1530
1531         spin_lock(&dentry->d_lock);
1532         list_for_each_entry(child, &dentry->d_subdirs, d_child) {
1533                 if (d_really_is_positive(child)) {
1534                         all_negative = false;
1535                         break;
1536                 }
1537         }
1538         spin_unlock(&dentry->d_lock);
1539
1540         if (all_negative)
1541                 shrink_dcache_parent(dentry);
1542 out:
1543         return all_negative;
1544 }
1545
1546 /*
1547  * Trim old(er) caps.
1548  *
1549  * Because we can't cache an inode without one or more caps, we do
1550  * this indirectly: if a cap is unused, we prune its aliases, at which
1551  * point the inode will hopefully get dropped to.
1552  *
1553  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1554  * memory pressure from the MDS, though, so it needn't be perfect.
1555  */
1556 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1557 {
1558         struct ceph_mds_session *session = arg;
1559         struct ceph_inode_info *ci = ceph_inode(inode);
1560         int used, wanted, oissued, mine;
1561
1562         if (session->s_trim_caps <= 0)
1563                 return -1;
1564
1565         spin_lock(&ci->i_ceph_lock);
1566         mine = cap->issued | cap->implemented;
1567         used = __ceph_caps_used(ci);
1568         wanted = __ceph_caps_file_wanted(ci);
1569         oissued = __ceph_caps_issued_other(ci, cap);
1570
1571         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1572              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1573              ceph_cap_string(used), ceph_cap_string(wanted));
1574         if (cap == ci->i_auth_cap) {
1575                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1576                     !list_empty(&ci->i_cap_snaps))
1577                         goto out;
1578                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1579                         goto out;
1580                 /* Note: it's possible that i_filelock_ref becomes non-zero
1581                  * after dropping auth caps. It doesn't hurt because reply
1582                  * of lock mds request will re-add auth caps. */
1583                 if (atomic_read(&ci->i_filelock_ref) > 0)
1584                         goto out;
1585         }
1586         /* The inode has cached pages, but it's no longer used.
1587          * we can safely drop it */
1588         if (wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1589             !(oissued & CEPH_CAP_FILE_CACHE)) {
1590           used = 0;
1591           oissued = 0;
1592         }
1593         if ((used | wanted) & ~oissued & mine)
1594                 goto out;   /* we need these caps */
1595
1596         if (oissued) {
1597                 /* we aren't the only cap.. just remove us */
1598                 __ceph_remove_cap(cap, true);
1599                 session->s_trim_caps--;
1600         } else {
1601                 struct dentry *dentry;
1602                 /* try dropping referring dentries */
1603                 spin_unlock(&ci->i_ceph_lock);
1604                 dentry = d_find_any_alias(inode);
1605                 if (dentry && drop_negative_children(dentry)) {
1606                         int count;
1607                         dput(dentry);
1608                         d_prune_aliases(inode);
1609                         count = atomic_read(&inode->i_count);
1610                         if (count == 1)
1611                                 session->s_trim_caps--;
1612                         dout("trim_caps_cb %p cap %p pruned, count now %d\n",
1613                              inode, cap, count);
1614                 } else {
1615                         dput(dentry);
1616                 }
1617                 return 0;
1618         }
1619
1620 out:
1621         spin_unlock(&ci->i_ceph_lock);
1622         return 0;
1623 }
1624
1625 /*
1626  * Trim session cap count down to some max number.
1627  */
1628 int ceph_trim_caps(struct ceph_mds_client *mdsc,
1629                    struct ceph_mds_session *session,
1630                    int max_caps)
1631 {
1632         int trim_caps = session->s_nr_caps - max_caps;
1633
1634         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1635              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1636         if (trim_caps > 0) {
1637                 session->s_trim_caps = trim_caps;
1638                 iterate_session_caps(session, trim_caps_cb, session);
1639                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1640                      session->s_mds, session->s_nr_caps, max_caps,
1641                         trim_caps - session->s_trim_caps);
1642                 session->s_trim_caps = 0;
1643         }
1644
1645         ceph_send_cap_releases(mdsc, session);
1646         return 0;
1647 }
1648
1649 static int check_caps_flush(struct ceph_mds_client *mdsc,
1650                             u64 want_flush_tid)
1651 {
1652         int ret = 1;
1653
1654         spin_lock(&mdsc->cap_dirty_lock);
1655         if (!list_empty(&mdsc->cap_flush_list)) {
1656                 struct ceph_cap_flush *cf =
1657                         list_first_entry(&mdsc->cap_flush_list,
1658                                          struct ceph_cap_flush, g_list);
1659                 if (cf->tid <= want_flush_tid) {
1660                         dout("check_caps_flush still flushing tid "
1661                              "%llu <= %llu\n", cf->tid, want_flush_tid);
1662                         ret = 0;
1663                 }
1664         }
1665         spin_unlock(&mdsc->cap_dirty_lock);
1666         return ret;
1667 }
1668
1669 /*
1670  * flush all dirty inode data to disk.
1671  *
1672  * returns true if we've flushed through want_flush_tid
1673  */
1674 static void wait_caps_flush(struct ceph_mds_client *mdsc,
1675                             u64 want_flush_tid)
1676 {
1677         dout("check_caps_flush want %llu\n", want_flush_tid);
1678
1679         wait_event(mdsc->cap_flushing_wq,
1680                    check_caps_flush(mdsc, want_flush_tid));
1681
1682         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
1683 }
1684
1685 /*
1686  * called under s_mutex
1687  */
1688 void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1689                             struct ceph_mds_session *session)
1690 {
1691         struct ceph_msg *msg = NULL;
1692         struct ceph_mds_cap_release *head;
1693         struct ceph_mds_cap_item *item;
1694         struct ceph_osd_client *osdc = &mdsc->fsc->client->osdc;
1695         struct ceph_cap *cap;
1696         LIST_HEAD(tmp_list);
1697         int num_cap_releases;
1698         __le32  barrier, *cap_barrier;
1699
1700         down_read(&osdc->lock);
1701         barrier = cpu_to_le32(osdc->epoch_barrier);
1702         up_read(&osdc->lock);
1703
1704         spin_lock(&session->s_cap_lock);
1705 again:
1706         list_splice_init(&session->s_cap_releases, &tmp_list);
1707         num_cap_releases = session->s_num_cap_releases;
1708         session->s_num_cap_releases = 0;
1709         spin_unlock(&session->s_cap_lock);
1710
1711         while (!list_empty(&tmp_list)) {
1712                 if (!msg) {
1713                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1714                                         PAGE_SIZE, GFP_NOFS, false);
1715                         if (!msg)
1716                                 goto out_err;
1717                         head = msg->front.iov_base;
1718                         head->num = cpu_to_le32(0);
1719                         msg->front.iov_len = sizeof(*head);
1720
1721                         msg->hdr.version = cpu_to_le16(2);
1722                         msg->hdr.compat_version = cpu_to_le16(1);
1723                 }
1724
1725                 cap = list_first_entry(&tmp_list, struct ceph_cap,
1726                                         session_caps);
1727                 list_del(&cap->session_caps);
1728                 num_cap_releases--;
1729
1730                 head = msg->front.iov_base;
1731                 le32_add_cpu(&head->num, 1);
1732                 item = msg->front.iov_base + msg->front.iov_len;
1733                 item->ino = cpu_to_le64(cap->cap_ino);
1734                 item->cap_id = cpu_to_le64(cap->cap_id);
1735                 item->migrate_seq = cpu_to_le32(cap->mseq);
1736                 item->seq = cpu_to_le32(cap->issue_seq);
1737                 msg->front.iov_len += sizeof(*item);
1738
1739                 ceph_put_cap(mdsc, cap);
1740
1741                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1742                         // Append cap_barrier field
1743                         cap_barrier = msg->front.iov_base + msg->front.iov_len;
1744                         *cap_barrier = barrier;
1745                         msg->front.iov_len += sizeof(*cap_barrier);
1746
1747                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1748                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1749                         ceph_con_send(&session->s_con, msg);
1750                         msg = NULL;
1751                 }
1752         }
1753
1754         BUG_ON(num_cap_releases != 0);
1755
1756         spin_lock(&session->s_cap_lock);
1757         if (!list_empty(&session->s_cap_releases))
1758                 goto again;
1759         spin_unlock(&session->s_cap_lock);
1760
1761         if (msg) {
1762                 // Append cap_barrier field
1763                 cap_barrier = msg->front.iov_base + msg->front.iov_len;
1764                 *cap_barrier = barrier;
1765                 msg->front.iov_len += sizeof(*cap_barrier);
1766
1767                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1768                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1769                 ceph_con_send(&session->s_con, msg);
1770         }
1771         return;
1772 out_err:
1773         pr_err("send_cap_releases mds%d, failed to allocate message\n",
1774                 session->s_mds);
1775         spin_lock(&session->s_cap_lock);
1776         list_splice(&tmp_list, &session->s_cap_releases);
1777         session->s_num_cap_releases += num_cap_releases;
1778         spin_unlock(&session->s_cap_lock);
1779 }
1780
1781 /*
1782  * requests
1783  */
1784
1785 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
1786                                     struct inode *dir)
1787 {
1788         struct ceph_inode_info *ci = ceph_inode(dir);
1789         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
1790         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
1791         size_t size = sizeof(struct ceph_mds_reply_dir_entry);
1792         int order, num_entries;
1793
1794         spin_lock(&ci->i_ceph_lock);
1795         num_entries = ci->i_files + ci->i_subdirs;
1796         spin_unlock(&ci->i_ceph_lock);
1797         num_entries = max(num_entries, 1);
1798         num_entries = min(num_entries, opt->max_readdir);
1799
1800         order = get_order(size * num_entries);
1801         while (order >= 0) {
1802                 rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
1803                                                              __GFP_NOWARN,
1804                                                              order);
1805                 if (rinfo->dir_entries)
1806                         break;
1807                 order--;
1808         }
1809         if (!rinfo->dir_entries)
1810                 return -ENOMEM;
1811
1812         num_entries = (PAGE_SIZE << order) / size;
1813         num_entries = min(num_entries, opt->max_readdir);
1814
1815         rinfo->dir_buf_size = PAGE_SIZE << order;
1816         req->r_num_caps = num_entries + 1;
1817         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
1818         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
1819         return 0;
1820 }
1821
1822 /*
1823  * Create an mds request.
1824  */
1825 struct ceph_mds_request *
1826 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1827 {
1828         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1829         struct timespec64 ts;
1830
1831         if (!req)
1832                 return ERR_PTR(-ENOMEM);
1833
1834         mutex_init(&req->r_fill_mutex);
1835         req->r_mdsc = mdsc;
1836         req->r_started = jiffies;
1837         req->r_resend_mds = -1;
1838         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1839         INIT_LIST_HEAD(&req->r_unsafe_target_item);
1840         req->r_fmode = -1;
1841         kref_init(&req->r_kref);
1842         RB_CLEAR_NODE(&req->r_node);
1843         INIT_LIST_HEAD(&req->r_wait);
1844         init_completion(&req->r_completion);
1845         init_completion(&req->r_safe_completion);
1846         INIT_LIST_HEAD(&req->r_unsafe_item);
1847
1848         ktime_get_coarse_real_ts64(&ts);
1849         req->r_stamp = timespec64_trunc(ts, mdsc->fsc->sb->s_time_gran);
1850
1851         req->r_op = op;
1852         req->r_direct_mode = mode;
1853         return req;
1854 }
1855
1856 /*
1857  * return oldest (lowest) request, tid in request tree, 0 if none.
1858  *
1859  * called under mdsc->mutex.
1860  */
1861 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1862 {
1863         if (RB_EMPTY_ROOT(&mdsc->request_tree))
1864                 return NULL;
1865         return rb_entry(rb_first(&mdsc->request_tree),
1866                         struct ceph_mds_request, r_node);
1867 }
1868
1869 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1870 {
1871         return mdsc->oldest_tid;
1872 }
1873
1874 /*
1875  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1876  * on build_path_from_dentry in fs/cifs/dir.c.
1877  *
1878  * If @stop_on_nosnap, generate path relative to the first non-snapped
1879  * inode.
1880  *
1881  * Encode hidden .snap dirs as a double /, i.e.
1882  *   foo/.snap/bar -> foo//bar
1883  */
1884 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1885                            int stop_on_nosnap)
1886 {
1887         struct dentry *temp;
1888         char *path;
1889         int len, pos;
1890         unsigned seq;
1891
1892         if (!dentry)
1893                 return ERR_PTR(-EINVAL);
1894
1895 retry:
1896         len = 0;
1897         seq = read_seqbegin(&rename_lock);
1898         rcu_read_lock();
1899         for (temp = dentry; !IS_ROOT(temp);) {
1900                 struct inode *inode = d_inode(temp);
1901                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1902                         len++;  /* slash only */
1903                 else if (stop_on_nosnap && inode &&
1904                          ceph_snap(inode) == CEPH_NOSNAP)
1905                         break;
1906                 else
1907                         len += 1 + temp->d_name.len;
1908                 temp = temp->d_parent;
1909         }
1910         rcu_read_unlock();
1911         if (len)
1912                 len--;  /* no leading '/' */
1913
1914         path = kmalloc(len+1, GFP_NOFS);
1915         if (!path)
1916                 return ERR_PTR(-ENOMEM);
1917         pos = len;
1918         path[pos] = 0;  /* trailing null */
1919         rcu_read_lock();
1920         for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1921                 struct inode *inode;
1922
1923                 spin_lock(&temp->d_lock);
1924                 inode = d_inode(temp);
1925                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1926                         dout("build_path path+%d: %p SNAPDIR\n",
1927                              pos, temp);
1928                 } else if (stop_on_nosnap && inode &&
1929                            ceph_snap(inode) == CEPH_NOSNAP) {
1930                         spin_unlock(&temp->d_lock);
1931                         break;
1932                 } else {
1933                         pos -= temp->d_name.len;
1934                         if (pos < 0) {
1935                                 spin_unlock(&temp->d_lock);
1936                                 break;
1937                         }
1938                         strncpy(path + pos, temp->d_name.name,
1939                                 temp->d_name.len);
1940                 }
1941                 spin_unlock(&temp->d_lock);
1942                 if (pos)
1943                         path[--pos] = '/';
1944                 temp = temp->d_parent;
1945         }
1946         rcu_read_unlock();
1947         if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1948                 pr_err("build_path did not end path lookup where "
1949                        "expected, namelen is %d, pos is %d\n", len, pos);
1950                 /* presumably this is only possible if racing with a
1951                    rename of one of the parent directories (we can not
1952                    lock the dentries above us to prevent this, but
1953                    retrying should be harmless) */
1954                 kfree(path);
1955                 goto retry;
1956         }
1957
1958         *base = ceph_ino(d_inode(temp));
1959         *plen = len;
1960         dout("build_path on %p %d built %llx '%.*s'\n",
1961              dentry, d_count(dentry), *base, len, path);
1962         return path;
1963 }
1964
1965 static int build_dentry_path(struct dentry *dentry, struct inode *dir,
1966                              const char **ppath, int *ppathlen, u64 *pino,
1967                              int *pfreepath)
1968 {
1969         char *path;
1970
1971         rcu_read_lock();
1972         if (!dir)
1973                 dir = d_inode_rcu(dentry->d_parent);
1974         if (dir && ceph_snap(dir) == CEPH_NOSNAP) {
1975                 *pino = ceph_ino(dir);
1976                 rcu_read_unlock();
1977                 *ppath = dentry->d_name.name;
1978                 *ppathlen = dentry->d_name.len;
1979                 return 0;
1980         }
1981         rcu_read_unlock();
1982         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1983         if (IS_ERR(path))
1984                 return PTR_ERR(path);
1985         *ppath = path;
1986         *pfreepath = 1;
1987         return 0;
1988 }
1989
1990 static int build_inode_path(struct inode *inode,
1991                             const char **ppath, int *ppathlen, u64 *pino,
1992                             int *pfreepath)
1993 {
1994         struct dentry *dentry;
1995         char *path;
1996
1997         if (ceph_snap(inode) == CEPH_NOSNAP) {
1998                 *pino = ceph_ino(inode);
1999                 *ppathlen = 0;
2000                 return 0;
2001         }
2002         dentry = d_find_alias(inode);
2003         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2004         dput(dentry);
2005         if (IS_ERR(path))
2006                 return PTR_ERR(path);
2007         *ppath = path;
2008         *pfreepath = 1;
2009         return 0;
2010 }
2011
2012 /*
2013  * request arguments may be specified via an inode *, a dentry *, or
2014  * an explicit ino+path.
2015  */
2016 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
2017                                   struct inode *rdiri, const char *rpath,
2018                                   u64 rino, const char **ppath, int *pathlen,
2019                                   u64 *ino, int *freepath)
2020 {
2021         int r = 0;
2022
2023         if (rinode) {
2024                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
2025                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
2026                      ceph_snap(rinode));
2027         } else if (rdentry) {
2028                 r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
2029                                         freepath);
2030                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
2031                      *ppath);
2032         } else if (rpath || rino) {
2033                 *ino = rino;
2034                 *ppath = rpath;
2035                 *pathlen = rpath ? strlen(rpath) : 0;
2036                 dout(" path %.*s\n", *pathlen, rpath);
2037         }
2038
2039         return r;
2040 }
2041
2042 /*
2043  * called under mdsc->mutex
2044  */
2045 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
2046                                                struct ceph_mds_request *req,
2047                                                int mds, bool drop_cap_releases)
2048 {
2049         struct ceph_msg *msg;
2050         struct ceph_mds_request_head *head;
2051         const char *path1 = NULL;
2052         const char *path2 = NULL;
2053         u64 ino1 = 0, ino2 = 0;
2054         int pathlen1 = 0, pathlen2 = 0;
2055         int freepath1 = 0, freepath2 = 0;
2056         int len;
2057         u16 releases;
2058         void *p, *end;
2059         int ret;
2060
2061         ret = set_request_path_attr(req->r_inode, req->r_dentry,
2062                               req->r_parent, req->r_path1, req->r_ino1.ino,
2063                               &path1, &pathlen1, &ino1, &freepath1);
2064         if (ret < 0) {
2065                 msg = ERR_PTR(ret);
2066                 goto out;
2067         }
2068
2069         ret = set_request_path_attr(NULL, req->r_old_dentry,
2070                               req->r_old_dentry_dir,
2071                               req->r_path2, req->r_ino2.ino,
2072                               &path2, &pathlen2, &ino2, &freepath2);
2073         if (ret < 0) {
2074                 msg = ERR_PTR(ret);
2075                 goto out_free1;
2076         }
2077
2078         len = sizeof(*head) +
2079                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
2080                 sizeof(struct ceph_timespec);
2081
2082         /* calculate (max) length for cap releases */
2083         len += sizeof(struct ceph_mds_request_release) *
2084                 (!!req->r_inode_drop + !!req->r_dentry_drop +
2085                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
2086         if (req->r_dentry_drop)
2087                 len += req->r_dentry->d_name.len;
2088         if (req->r_old_dentry_drop)
2089                 len += req->r_old_dentry->d_name.len;
2090
2091         msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
2092         if (!msg) {
2093                 msg = ERR_PTR(-ENOMEM);
2094                 goto out_free2;
2095         }
2096
2097         msg->hdr.version = cpu_to_le16(2);
2098         msg->hdr.tid = cpu_to_le64(req->r_tid);
2099
2100         head = msg->front.iov_base;
2101         p = msg->front.iov_base + sizeof(*head);
2102         end = msg->front.iov_base + msg->front.iov_len;
2103
2104         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
2105         head->op = cpu_to_le32(req->r_op);
2106         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
2107         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
2108         head->args = req->r_args;
2109
2110         ceph_encode_filepath(&p, end, ino1, path1);
2111         ceph_encode_filepath(&p, end, ino2, path2);
2112
2113         /* make note of release offset, in case we need to replay */
2114         req->r_request_release_offset = p - msg->front.iov_base;
2115
2116         /* cap releases */
2117         releases = 0;
2118         if (req->r_inode_drop)
2119                 releases += ceph_encode_inode_release(&p,
2120                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
2121                       mds, req->r_inode_drop, req->r_inode_unless, 0);
2122         if (req->r_dentry_drop)
2123                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
2124                                 req->r_parent, mds, req->r_dentry_drop,
2125                                 req->r_dentry_unless);
2126         if (req->r_old_dentry_drop)
2127                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2128                                 req->r_old_dentry_dir, mds,
2129                                 req->r_old_dentry_drop,
2130                                 req->r_old_dentry_unless);
2131         if (req->r_old_inode_drop)
2132                 releases += ceph_encode_inode_release(&p,
2133                       d_inode(req->r_old_dentry),
2134                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2135
2136         if (drop_cap_releases) {
2137                 releases = 0;
2138                 p = msg->front.iov_base + req->r_request_release_offset;
2139         }
2140
2141         head->num_releases = cpu_to_le16(releases);
2142
2143         /* time stamp */
2144         {
2145                 struct ceph_timespec ts;
2146                 ceph_encode_timespec64(&ts, &req->r_stamp);
2147                 ceph_encode_copy(&p, &ts, sizeof(ts));
2148         }
2149
2150         BUG_ON(p > end);
2151         msg->front.iov_len = p - msg->front.iov_base;
2152         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2153
2154         if (req->r_pagelist) {
2155                 struct ceph_pagelist *pagelist = req->r_pagelist;
2156                 ceph_msg_data_add_pagelist(msg, pagelist);
2157                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2158         } else {
2159                 msg->hdr.data_len = 0;
2160         }
2161
2162         msg->hdr.data_off = cpu_to_le16(0);
2163
2164 out_free2:
2165         if (freepath2)
2166                 kfree((char *)path2);
2167 out_free1:
2168         if (freepath1)
2169                 kfree((char *)path1);
2170 out:
2171         return msg;
2172 }
2173
2174 /*
2175  * called under mdsc->mutex if error, under no mutex if
2176  * success.
2177  */
2178 static void complete_request(struct ceph_mds_client *mdsc,
2179                              struct ceph_mds_request *req)
2180 {
2181         if (req->r_callback)
2182                 req->r_callback(mdsc, req);
2183         else
2184                 complete_all(&req->r_completion);
2185 }
2186
2187 /*
2188  * called under mdsc->mutex
2189  */
2190 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2191                                   struct ceph_mds_request *req,
2192                                   int mds, bool drop_cap_releases)
2193 {
2194         struct ceph_mds_request_head *rhead;
2195         struct ceph_msg *msg;
2196         int flags = 0;
2197
2198         req->r_attempts++;
2199         if (req->r_inode) {
2200                 struct ceph_cap *cap =
2201                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2202
2203                 if (cap)
2204                         req->r_sent_on_mseq = cap->mseq;
2205                 else
2206                         req->r_sent_on_mseq = -1;
2207         }
2208         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2209              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2210
2211         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2212                 void *p;
2213                 /*
2214                  * Replay.  Do not regenerate message (and rebuild
2215                  * paths, etc.); just use the original message.
2216                  * Rebuilding paths will break for renames because
2217                  * d_move mangles the src name.
2218                  */
2219                 msg = req->r_request;
2220                 rhead = msg->front.iov_base;
2221
2222                 flags = le32_to_cpu(rhead->flags);
2223                 flags |= CEPH_MDS_FLAG_REPLAY;
2224                 rhead->flags = cpu_to_le32(flags);
2225
2226                 if (req->r_target_inode)
2227                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2228
2229                 rhead->num_retry = req->r_attempts - 1;
2230
2231                 /* remove cap/dentry releases from message */
2232                 rhead->num_releases = 0;
2233
2234                 /* time stamp */
2235                 p = msg->front.iov_base + req->r_request_release_offset;
2236                 {
2237                         struct ceph_timespec ts;
2238                         ceph_encode_timespec64(&ts, &req->r_stamp);
2239                         ceph_encode_copy(&p, &ts, sizeof(ts));
2240                 }
2241
2242                 msg->front.iov_len = p - msg->front.iov_base;
2243                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2244                 return 0;
2245         }
2246
2247         if (req->r_request) {
2248                 ceph_msg_put(req->r_request);
2249                 req->r_request = NULL;
2250         }
2251         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2252         if (IS_ERR(msg)) {
2253                 req->r_err = PTR_ERR(msg);
2254                 return PTR_ERR(msg);
2255         }
2256         req->r_request = msg;
2257
2258         rhead = msg->front.iov_base;
2259         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2260         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2261                 flags |= CEPH_MDS_FLAG_REPLAY;
2262         if (req->r_parent)
2263                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2264         rhead->flags = cpu_to_le32(flags);
2265         rhead->num_fwd = req->r_num_fwd;
2266         rhead->num_retry = req->r_attempts - 1;
2267         rhead->ino = 0;
2268
2269         dout(" r_parent = %p\n", req->r_parent);
2270         return 0;
2271 }
2272
2273 /*
2274  * send request, or put it on the appropriate wait list.
2275  */
2276 static void __do_request(struct ceph_mds_client *mdsc,
2277                         struct ceph_mds_request *req)
2278 {
2279         struct ceph_mds_session *session = NULL;
2280         int mds = -1;
2281         int err = 0;
2282
2283         if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2284                 if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2285                         __unregister_request(mdsc, req);
2286                 return;
2287         }
2288
2289         if (req->r_timeout &&
2290             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2291                 dout("do_request timed out\n");
2292                 err = -EIO;
2293                 goto finish;
2294         }
2295         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2296                 dout("do_request forced umount\n");
2297                 err = -EIO;
2298                 goto finish;
2299         }
2300         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2301                 if (mdsc->mdsmap_err) {
2302                         err = mdsc->mdsmap_err;
2303                         dout("do_request mdsmap err %d\n", err);
2304                         goto finish;
2305                 }
2306                 if (mdsc->mdsmap->m_epoch == 0) {
2307                         dout("do_request no mdsmap, waiting for map\n");
2308                         list_add(&req->r_wait, &mdsc->waiting_for_map);
2309                         return;
2310                 }
2311                 if (!(mdsc->fsc->mount_options->flags &
2312                       CEPH_MOUNT_OPT_MOUNTWAIT) &&
2313                     !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2314                         err = -ENOENT;
2315                         pr_info("probably no mds server is up\n");
2316                         goto finish;
2317                 }
2318         }
2319
2320         put_request_session(req);
2321
2322         mds = __choose_mds(mdsc, req);
2323         if (mds < 0 ||
2324             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2325                 dout("do_request no mds or not active, waiting for map\n");
2326                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2327                 return;
2328         }
2329
2330         /* get, open session */
2331         session = __ceph_lookup_mds_session(mdsc, mds);
2332         if (!session) {
2333                 session = register_session(mdsc, mds);
2334                 if (IS_ERR(session)) {
2335                         err = PTR_ERR(session);
2336                         goto finish;
2337                 }
2338         }
2339         req->r_session = get_session(session);
2340
2341         dout("do_request mds%d session %p state %s\n", mds, session,
2342              ceph_session_state_name(session->s_state));
2343         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2344             session->s_state != CEPH_MDS_SESSION_HUNG) {
2345                 if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2346                         err = -EACCES;
2347                         goto out_session;
2348                 }
2349                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2350                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2351                         __open_session(mdsc, session);
2352                 list_add(&req->r_wait, &session->s_waiting);
2353                 goto out_session;
2354         }
2355
2356         /* send request */
2357         req->r_resend_mds = -1;   /* forget any previous mds hint */
2358
2359         if (req->r_request_started == 0)   /* note request start time */
2360                 req->r_request_started = jiffies;
2361
2362         err = __prepare_send_request(mdsc, req, mds, false);
2363         if (!err) {
2364                 ceph_msg_get(req->r_request);
2365                 ceph_con_send(&session->s_con, req->r_request);
2366         }
2367
2368 out_session:
2369         ceph_put_mds_session(session);
2370 finish:
2371         if (err) {
2372                 dout("__do_request early error %d\n", err);
2373                 req->r_err = err;
2374                 complete_request(mdsc, req);
2375                 __unregister_request(mdsc, req);
2376         }
2377         return;
2378 }
2379
2380 /*
2381  * called under mdsc->mutex
2382  */
2383 static void __wake_requests(struct ceph_mds_client *mdsc,
2384                             struct list_head *head)
2385 {
2386         struct ceph_mds_request *req;
2387         LIST_HEAD(tmp_list);
2388
2389         list_splice_init(head, &tmp_list);
2390
2391         while (!list_empty(&tmp_list)) {
2392                 req = list_entry(tmp_list.next,
2393                                  struct ceph_mds_request, r_wait);
2394                 list_del_init(&req->r_wait);
2395                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2396                 __do_request(mdsc, req);
2397         }
2398 }
2399
2400 /*
2401  * Wake up threads with requests pending for @mds, so that they can
2402  * resubmit their requests to a possibly different mds.
2403  */
2404 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2405 {
2406         struct ceph_mds_request *req;
2407         struct rb_node *p = rb_first(&mdsc->request_tree);
2408
2409         dout("kick_requests mds%d\n", mds);
2410         while (p) {
2411                 req = rb_entry(p, struct ceph_mds_request, r_node);
2412                 p = rb_next(p);
2413                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2414                         continue;
2415                 if (req->r_attempts > 0)
2416                         continue; /* only new requests */
2417                 if (req->r_session &&
2418                     req->r_session->s_mds == mds) {
2419                         dout(" kicking tid %llu\n", req->r_tid);
2420                         list_del_init(&req->r_wait);
2421                         __do_request(mdsc, req);
2422                 }
2423         }
2424 }
2425
2426 void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
2427                               struct ceph_mds_request *req)
2428 {
2429         dout("submit_request on %p\n", req);
2430         mutex_lock(&mdsc->mutex);
2431         __register_request(mdsc, req, NULL);
2432         __do_request(mdsc, req);
2433         mutex_unlock(&mdsc->mutex);
2434 }
2435
2436 /*
2437  * Synchrously perform an mds request.  Take care of all of the
2438  * session setup, forwarding, retry details.
2439  */
2440 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2441                          struct inode *dir,
2442                          struct ceph_mds_request *req)
2443 {
2444         int err;
2445
2446         dout("do_request on %p\n", req);
2447
2448         /* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
2449         if (req->r_inode)
2450                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2451         if (req->r_parent)
2452                 ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
2453         if (req->r_old_dentry_dir)
2454                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2455                                   CEPH_CAP_PIN);
2456
2457         /* issue */
2458         mutex_lock(&mdsc->mutex);
2459         __register_request(mdsc, req, dir);
2460         __do_request(mdsc, req);
2461
2462         if (req->r_err) {
2463                 err = req->r_err;
2464                 goto out;
2465         }
2466
2467         /* wait */
2468         mutex_unlock(&mdsc->mutex);
2469         dout("do_request waiting\n");
2470         if (!req->r_timeout && req->r_wait_for_completion) {
2471                 err = req->r_wait_for_completion(mdsc, req);
2472         } else {
2473                 long timeleft = wait_for_completion_killable_timeout(
2474                                         &req->r_completion,
2475                                         ceph_timeout_jiffies(req->r_timeout));
2476                 if (timeleft > 0)
2477                         err = 0;
2478                 else if (!timeleft)
2479                         err = -EIO;  /* timed out */
2480                 else
2481                         err = timeleft;  /* killed */
2482         }
2483         dout("do_request waited, got %d\n", err);
2484         mutex_lock(&mdsc->mutex);
2485
2486         /* only abort if we didn't race with a real reply */
2487         if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2488                 err = le32_to_cpu(req->r_reply_info.head->result);
2489         } else if (err < 0) {
2490                 dout("aborted request %lld with %d\n", req->r_tid, err);
2491
2492                 /*
2493                  * ensure we aren't running concurrently with
2494                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2495                  * rely on locks (dir mutex) held by our caller.
2496                  */
2497                 mutex_lock(&req->r_fill_mutex);
2498                 req->r_err = err;
2499                 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
2500                 mutex_unlock(&req->r_fill_mutex);
2501
2502                 if (req->r_parent &&
2503                     (req->r_op & CEPH_MDS_OP_WRITE))
2504                         ceph_invalidate_dir_request(req);
2505         } else {
2506                 err = req->r_err;
2507         }
2508
2509 out:
2510         mutex_unlock(&mdsc->mutex);
2511         dout("do_request %p done, result %d\n", req, err);
2512         return err;
2513 }
2514
2515 /*
2516  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2517  * namespace request.
2518  */
2519 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2520 {
2521         struct inode *dir = req->r_parent;
2522         struct inode *old_dir = req->r_old_dentry_dir;
2523
2524         dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
2525
2526         ceph_dir_clear_complete(dir);
2527         if (old_dir)
2528                 ceph_dir_clear_complete(old_dir);
2529         if (req->r_dentry)
2530                 ceph_invalidate_dentry_lease(req->r_dentry);
2531         if (req->r_old_dentry)
2532                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2533 }
2534
2535 /*
2536  * Handle mds reply.
2537  *
2538  * We take the session mutex and parse and process the reply immediately.
2539  * This preserves the logical ordering of replies, capabilities, etc., sent
2540  * by the MDS as they are applied to our local cache.
2541  */
2542 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2543 {
2544         struct ceph_mds_client *mdsc = session->s_mdsc;
2545         struct ceph_mds_request *req;
2546         struct ceph_mds_reply_head *head = msg->front.iov_base;
2547         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2548         struct ceph_snap_realm *realm;
2549         u64 tid;
2550         int err, result;
2551         int mds = session->s_mds;
2552
2553         if (msg->front.iov_len < sizeof(*head)) {
2554                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2555                 ceph_msg_dump(msg);
2556                 return;
2557         }
2558
2559         /* get request, session */
2560         tid = le64_to_cpu(msg->hdr.tid);
2561         mutex_lock(&mdsc->mutex);
2562         req = lookup_get_request(mdsc, tid);
2563         if (!req) {
2564                 dout("handle_reply on unknown tid %llu\n", tid);
2565                 mutex_unlock(&mdsc->mutex);
2566                 return;
2567         }
2568         dout("handle_reply %p\n", req);
2569
2570         /* correct session? */
2571         if (req->r_session != session) {
2572                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2573                        " not mds%d\n", tid, session->s_mds,
2574                        req->r_session ? req->r_session->s_mds : -1);
2575                 mutex_unlock(&mdsc->mutex);
2576                 goto out;
2577         }
2578
2579         /* dup? */
2580         if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
2581             (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
2582                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2583                            head->safe ? "safe" : "unsafe", tid, mds);
2584                 mutex_unlock(&mdsc->mutex);
2585                 goto out;
2586         }
2587         if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
2588                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2589                            tid, mds);
2590                 mutex_unlock(&mdsc->mutex);
2591                 goto out;
2592         }
2593
2594         result = le32_to_cpu(head->result);
2595
2596         /*
2597          * Handle an ESTALE
2598          * if we're not talking to the authority, send to them
2599          * if the authority has changed while we weren't looking,
2600          * send to new authority
2601          * Otherwise we just have to return an ESTALE
2602          */
2603         if (result == -ESTALE) {
2604                 dout("got ESTALE on request %llu\n", req->r_tid);
2605                 req->r_resend_mds = -1;
2606                 if (req->r_direct_mode != USE_AUTH_MDS) {
2607                         dout("not using auth, setting for that now\n");
2608                         req->r_direct_mode = USE_AUTH_MDS;
2609                         __do_request(mdsc, req);
2610                         mutex_unlock(&mdsc->mutex);
2611                         goto out;
2612                 } else  {
2613                         int mds = __choose_mds(mdsc, req);
2614                         if (mds >= 0 && mds != req->r_session->s_mds) {
2615                                 dout("but auth changed, so resending\n");
2616                                 __do_request(mdsc, req);
2617                                 mutex_unlock(&mdsc->mutex);
2618                                 goto out;
2619                         }
2620                 }
2621                 dout("have to return ESTALE on request %llu\n", req->r_tid);
2622         }
2623
2624
2625         if (head->safe) {
2626                 set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
2627                 __unregister_request(mdsc, req);
2628
2629                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2630                         /*
2631                          * We already handled the unsafe response, now do the
2632                          * cleanup.  No need to examine the response; the MDS
2633                          * doesn't include any result info in the safe
2634                          * response.  And even if it did, there is nothing
2635                          * useful we could do with a revised return value.
2636                          */
2637                         dout("got safe reply %llu, mds%d\n", tid, mds);
2638
2639                         /* last unsafe request during umount? */
2640                         if (mdsc->stopping && !__get_oldest_req(mdsc))
2641                                 complete_all(&mdsc->safe_umount_waiters);
2642                         mutex_unlock(&mdsc->mutex);
2643                         goto out;
2644                 }
2645         } else {
2646                 set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
2647                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2648                 if (req->r_unsafe_dir) {
2649                         struct ceph_inode_info *ci =
2650                                         ceph_inode(req->r_unsafe_dir);
2651                         spin_lock(&ci->i_unsafe_lock);
2652                         list_add_tail(&req->r_unsafe_dir_item,
2653                                       &ci->i_unsafe_dirops);
2654                         spin_unlock(&ci->i_unsafe_lock);
2655                 }
2656         }
2657
2658         dout("handle_reply tid %lld result %d\n", tid, result);
2659         rinfo = &req->r_reply_info;
2660         err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2661         mutex_unlock(&mdsc->mutex);
2662
2663         mutex_lock(&session->s_mutex);
2664         if (err < 0) {
2665                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2666                 ceph_msg_dump(msg);
2667                 goto out_err;
2668         }
2669
2670         /* snap trace */
2671         realm = NULL;
2672         if (rinfo->snapblob_len) {
2673                 down_write(&mdsc->snap_rwsem);
2674                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2675                                 rinfo->snapblob + rinfo->snapblob_len,
2676                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2677                                 &realm);
2678                 downgrade_write(&mdsc->snap_rwsem);
2679         } else {
2680                 down_read(&mdsc->snap_rwsem);
2681         }
2682
2683         /* insert trace into our cache */
2684         mutex_lock(&req->r_fill_mutex);
2685         current->journal_info = req;
2686         err = ceph_fill_trace(mdsc->fsc->sb, req);
2687         if (err == 0) {
2688                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2689                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2690                         ceph_readdir_prepopulate(req, req->r_session);
2691                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2692         }
2693         current->journal_info = NULL;
2694         mutex_unlock(&req->r_fill_mutex);
2695
2696         up_read(&mdsc->snap_rwsem);
2697         if (realm)
2698                 ceph_put_snap_realm(mdsc, realm);
2699
2700         if (err == 0 && req->r_target_inode &&
2701             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2702                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
2703                 spin_lock(&ci->i_unsafe_lock);
2704                 list_add_tail(&req->r_unsafe_target_item, &ci->i_unsafe_iops);
2705                 spin_unlock(&ci->i_unsafe_lock);
2706         }
2707 out_err:
2708         mutex_lock(&mdsc->mutex);
2709         if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
2710                 if (err) {
2711                         req->r_err = err;
2712                 } else {
2713                         req->r_reply =  ceph_msg_get(msg);
2714                         set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
2715                 }
2716         } else {
2717                 dout("reply arrived after request %lld was aborted\n", tid);
2718         }
2719         mutex_unlock(&mdsc->mutex);
2720
2721         mutex_unlock(&session->s_mutex);
2722
2723         /* kick calling process */
2724         complete_request(mdsc, req);
2725 out:
2726         ceph_mdsc_put_request(req);
2727         return;
2728 }
2729
2730
2731
2732 /*
2733  * handle mds notification that our request has been forwarded.
2734  */
2735 static void handle_forward(struct ceph_mds_client *mdsc,
2736                            struct ceph_mds_session *session,
2737                            struct ceph_msg *msg)
2738 {
2739         struct ceph_mds_request *req;
2740         u64 tid = le64_to_cpu(msg->hdr.tid);
2741         u32 next_mds;
2742         u32 fwd_seq;
2743         int err = -EINVAL;
2744         void *p = msg->front.iov_base;
2745         void *end = p + msg->front.iov_len;
2746
2747         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2748         next_mds = ceph_decode_32(&p);
2749         fwd_seq = ceph_decode_32(&p);
2750
2751         mutex_lock(&mdsc->mutex);
2752         req = lookup_get_request(mdsc, tid);
2753         if (!req) {
2754                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2755                 goto out;  /* dup reply? */
2756         }
2757
2758         if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
2759                 dout("forward tid %llu aborted, unregistering\n", tid);
2760                 __unregister_request(mdsc, req);
2761         } else if (fwd_seq <= req->r_num_fwd) {
2762                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2763                      tid, next_mds, req->r_num_fwd, fwd_seq);
2764         } else {
2765                 /* resend. forward race not possible; mds would drop */
2766                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2767                 BUG_ON(req->r_err);
2768                 BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
2769                 req->r_attempts = 0;
2770                 req->r_num_fwd = fwd_seq;
2771                 req->r_resend_mds = next_mds;
2772                 put_request_session(req);
2773                 __do_request(mdsc, req);
2774         }
2775         ceph_mdsc_put_request(req);
2776 out:
2777         mutex_unlock(&mdsc->mutex);
2778         return;
2779
2780 bad:
2781         pr_err("mdsc_handle_forward decode error err=%d\n", err);
2782 }
2783
2784 static int __decode_and_drop_session_metadata(void **p, void *end)
2785 {
2786         /* map<string,string> */
2787         u32 n;
2788         ceph_decode_32_safe(p, end, n, bad);
2789         while (n-- > 0) {
2790                 u32 len;
2791                 ceph_decode_32_safe(p, end, len, bad);
2792                 ceph_decode_need(p, end, len, bad);
2793                 *p += len;
2794                 ceph_decode_32_safe(p, end, len, bad);
2795                 ceph_decode_need(p, end, len, bad);
2796                 *p += len;
2797         }
2798         return 0;
2799 bad:
2800         return -1;
2801 }
2802
2803 /*
2804  * handle a mds session control message
2805  */
2806 static void handle_session(struct ceph_mds_session *session,
2807                            struct ceph_msg *msg)
2808 {
2809         struct ceph_mds_client *mdsc = session->s_mdsc;
2810         int mds = session->s_mds;
2811         int msg_version = le16_to_cpu(msg->hdr.version);
2812         void *p = msg->front.iov_base;
2813         void *end = p + msg->front.iov_len;
2814         struct ceph_mds_session_head *h;
2815         u32 op;
2816         u64 seq;
2817         unsigned long features = 0;
2818         int wake = 0;
2819
2820         /* decode */
2821         ceph_decode_need(&p, end, sizeof(*h), bad);
2822         h = p;
2823         p += sizeof(*h);
2824
2825         op = le32_to_cpu(h->op);
2826         seq = le64_to_cpu(h->seq);
2827
2828         if (msg_version >= 3) {
2829                 u32 len;
2830                 /* version >= 2, metadata */
2831                 if (__decode_and_drop_session_metadata(&p, end) < 0)
2832                         goto bad;
2833                 /* version >= 3, feature bits */
2834                 ceph_decode_32_safe(&p, end, len, bad);
2835                 ceph_decode_need(&p, end, len, bad);
2836                 memcpy(&features, p, min_t(size_t, len, sizeof(features)));
2837                 p += len;
2838         }
2839
2840         mutex_lock(&mdsc->mutex);
2841         if (op == CEPH_SESSION_CLOSE) {
2842                 get_session(session);
2843                 __unregister_session(mdsc, session);
2844         }
2845         /* FIXME: this ttl calculation is generous */
2846         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2847         mutex_unlock(&mdsc->mutex);
2848
2849         mutex_lock(&session->s_mutex);
2850
2851         dout("handle_session mds%d %s %p state %s seq %llu\n",
2852              mds, ceph_session_op_name(op), session,
2853              ceph_session_state_name(session->s_state), seq);
2854
2855         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2856                 session->s_state = CEPH_MDS_SESSION_OPEN;
2857                 pr_info("mds%d came back\n", session->s_mds);
2858         }
2859
2860         switch (op) {
2861         case CEPH_SESSION_OPEN:
2862                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2863                         pr_info("mds%d reconnect success\n", session->s_mds);
2864                 session->s_state = CEPH_MDS_SESSION_OPEN;
2865                 session->s_features = features;
2866                 renewed_caps(mdsc, session, 0);
2867                 wake = 1;
2868                 if (mdsc->stopping)
2869                         __close_session(mdsc, session);
2870                 break;
2871
2872         case CEPH_SESSION_RENEWCAPS:
2873                 if (session->s_renew_seq == seq)
2874                         renewed_caps(mdsc, session, 1);
2875                 break;
2876
2877         case CEPH_SESSION_CLOSE:
2878                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2879                         pr_info("mds%d reconnect denied\n", session->s_mds);
2880                 cleanup_session_requests(mdsc, session);
2881                 remove_session_caps(session);
2882                 wake = 2; /* for good measure */
2883                 wake_up_all(&mdsc->session_close_wq);
2884                 break;
2885
2886         case CEPH_SESSION_STALE:
2887                 pr_info("mds%d caps went stale, renewing\n",
2888                         session->s_mds);
2889                 spin_lock(&session->s_gen_ttl_lock);
2890                 session->s_cap_gen++;
2891                 session->s_cap_ttl = jiffies - 1;
2892                 spin_unlock(&session->s_gen_ttl_lock);
2893                 send_renew_caps(mdsc, session);
2894                 break;
2895
2896         case CEPH_SESSION_RECALL_STATE:
2897                 ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2898                 break;
2899
2900         case CEPH_SESSION_FLUSHMSG:
2901                 send_flushmsg_ack(mdsc, session, seq);
2902                 break;
2903
2904         case CEPH_SESSION_FORCE_RO:
2905                 dout("force_session_readonly %p\n", session);
2906                 spin_lock(&session->s_cap_lock);
2907                 session->s_readonly = true;
2908                 spin_unlock(&session->s_cap_lock);
2909                 wake_up_session_caps(session, FORCE_RO);
2910                 break;
2911
2912         case CEPH_SESSION_REJECT:
2913                 WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
2914                 pr_info("mds%d rejected session\n", session->s_mds);
2915                 session->s_state = CEPH_MDS_SESSION_REJECTED;
2916                 cleanup_session_requests(mdsc, session);
2917                 remove_session_caps(session);
2918                 wake = 2; /* for good measure */
2919                 break;
2920
2921         default:
2922                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2923                 WARN_ON(1);
2924         }
2925
2926         mutex_unlock(&session->s_mutex);
2927         if (wake) {
2928                 mutex_lock(&mdsc->mutex);
2929                 __wake_requests(mdsc, &session->s_waiting);
2930                 if (wake == 2)
2931                         kick_requests(mdsc, mds);
2932                 mutex_unlock(&mdsc->mutex);
2933         }
2934         if (op == CEPH_SESSION_CLOSE)
2935                 ceph_put_mds_session(session);
2936         return;
2937
2938 bad:
2939         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2940                (int)msg->front.iov_len);
2941         ceph_msg_dump(msg);
2942         return;
2943 }
2944
2945
2946 /*
2947  * called under session->mutex.
2948  */
2949 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2950                                    struct ceph_mds_session *session)
2951 {
2952         struct ceph_mds_request *req, *nreq;
2953         struct rb_node *p;
2954         int err;
2955
2956         dout("replay_unsafe_requests mds%d\n", session->s_mds);
2957
2958         mutex_lock(&mdsc->mutex);
2959         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2960                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
2961                 if (!err) {
2962                         ceph_msg_get(req->r_request);
2963                         ceph_con_send(&session->s_con, req->r_request);
2964                 }
2965         }
2966
2967         /*
2968          * also re-send old requests when MDS enters reconnect stage. So that MDS
2969          * can process completed request in clientreplay stage.
2970          */
2971         p = rb_first(&mdsc->request_tree);
2972         while (p) {
2973                 req = rb_entry(p, struct ceph_mds_request, r_node);
2974                 p = rb_next(p);
2975                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2976                         continue;
2977                 if (req->r_attempts == 0)
2978                         continue; /* only old requests */
2979                 if (req->r_session &&
2980                     req->r_session->s_mds == session->s_mds) {
2981                         err = __prepare_send_request(mdsc, req,
2982                                                      session->s_mds, true);
2983                         if (!err) {
2984                                 ceph_msg_get(req->r_request);
2985                                 ceph_con_send(&session->s_con, req->r_request);
2986                         }
2987                 }
2988         }
2989         mutex_unlock(&mdsc->mutex);
2990 }
2991
2992 static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
2993 {
2994         struct ceph_msg *reply;
2995         struct ceph_pagelist *_pagelist;
2996         struct page *page;
2997         __le32 *addr;
2998         int err = -ENOMEM;
2999
3000         if (!recon_state->allow_multi)
3001                 return -ENOSPC;
3002
3003         /* can't handle message that contains both caps and realm */
3004         BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3005
3006         /* pre-allocate new pagelist */
3007         _pagelist = ceph_pagelist_alloc(GFP_NOFS);
3008         if (!_pagelist)
3009                 return -ENOMEM;
3010
3011         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3012         if (!reply)
3013                 goto fail_msg;
3014
3015         /* placeholder for nr_caps */
3016         err = ceph_pagelist_encode_32(_pagelist, 0);
3017         if (err < 0)
3018                 goto fail;
3019
3020         if (recon_state->nr_caps) {
3021                 /* currently encoding caps */
3022                 err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3023                 if (err)
3024                         goto fail;
3025         } else {
3026                 /* placeholder for nr_realms (currently encoding relams) */
3027                 err = ceph_pagelist_encode_32(_pagelist, 0);
3028                 if (err < 0)
3029                         goto fail;
3030         }
3031
3032         err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3033         if (err)
3034                 goto fail;
3035
3036         page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3037         addr = kmap_atomic(page);
3038         if (recon_state->nr_caps) {
3039                 /* currently encoding caps */
3040                 *addr = cpu_to_le32(recon_state->nr_caps);
3041         } else {
3042                 /* currently encoding relams */
3043                 *(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3044         }
3045         kunmap_atomic(addr);
3046
3047         reply->hdr.version = cpu_to_le16(5);
3048         reply->hdr.compat_version = cpu_to_le16(4);
3049
3050         reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3051         ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3052
3053         ceph_con_send(&recon_state->session->s_con, reply);
3054         ceph_pagelist_release(recon_state->pagelist);
3055
3056         recon_state->pagelist = _pagelist;
3057         recon_state->nr_caps = 0;
3058         recon_state->nr_realms = 0;
3059         recon_state->msg_version = 5;
3060         return 0;
3061 fail:
3062         ceph_msg_put(reply);
3063 fail_msg:
3064         ceph_pagelist_release(_pagelist);
3065         return err;
3066 }
3067
3068 /*
3069  * Encode information about a cap for a reconnect with the MDS.
3070  */
3071 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
3072                           void *arg)
3073 {
3074         union {
3075                 struct ceph_mds_cap_reconnect v2;
3076                 struct ceph_mds_cap_reconnect_v1 v1;
3077         } rec;
3078         struct ceph_inode_info *ci = cap->ci;
3079         struct ceph_reconnect_state *recon_state = arg;
3080         struct ceph_pagelist *pagelist = recon_state->pagelist;
3081         int err;
3082         u64 snap_follows;
3083
3084         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3085              inode, ceph_vinop(inode), cap, cap->cap_id,
3086              ceph_cap_string(cap->issued));
3087
3088         spin_lock(&ci->i_ceph_lock);
3089         cap->seq = 0;        /* reset cap seq */
3090         cap->issue_seq = 0;  /* and issue_seq */
3091         cap->mseq = 0;       /* and migrate_seq */
3092         cap->cap_gen = cap->session->s_cap_gen;
3093
3094         if (recon_state->msg_version >= 2) {
3095                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3096                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3097                 rec.v2.issued = cpu_to_le32(cap->issued);
3098                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3099                 rec.v2.pathbase = 0;
3100                 rec.v2.flock_len = (__force __le32)
3101                         ((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3102         } else {
3103                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3104                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3105                 rec.v1.issued = cpu_to_le32(cap->issued);
3106                 rec.v1.size = cpu_to_le64(inode->i_size);
3107                 ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3108                 ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3109                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3110                 rec.v1.pathbase = 0;
3111         }
3112
3113         if (list_empty(&ci->i_cap_snaps)) {
3114                 snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3115         } else {
3116                 struct ceph_cap_snap *capsnap =
3117                         list_first_entry(&ci->i_cap_snaps,
3118                                          struct ceph_cap_snap, ci_item);
3119                 snap_follows = capsnap->follows;
3120         }
3121         spin_unlock(&ci->i_ceph_lock);
3122
3123         if (recon_state->msg_version >= 2) {
3124                 int num_fcntl_locks, num_flock_locks;
3125                 struct ceph_filelock *flocks = NULL;
3126                 size_t struct_len, total_len = sizeof(u64);
3127                 u8 struct_v = 0;
3128
3129 encode_again:
3130                 if (rec.v2.flock_len) {
3131                         ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
3132                 } else {
3133                         num_fcntl_locks = 0;
3134                         num_flock_locks = 0;
3135                 }
3136                 if (num_fcntl_locks + num_flock_locks > 0) {
3137                         flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
3138                                                sizeof(struct ceph_filelock),
3139                                                GFP_NOFS);
3140                         if (!flocks) {
3141                                 err = -ENOMEM;
3142                                 goto out_err;
3143                         }
3144                         err = ceph_encode_locks_to_buffer(inode, flocks,
3145                                                           num_fcntl_locks,
3146                                                           num_flock_locks);
3147                         if (err) {
3148                                 kfree(flocks);
3149                                 flocks = NULL;
3150                                 if (err == -ENOSPC)
3151                                         goto encode_again;
3152                                 goto out_err;
3153                         }
3154                 } else {
3155                         kfree(flocks);
3156                         flocks = NULL;
3157                 }
3158
3159                 if (recon_state->msg_version >= 3) {
3160                         /* version, compat_version and struct_len */
3161                         total_len += 2 * sizeof(u8) + sizeof(u32);
3162                         struct_v = 2;
3163                 }
3164                 /*
3165                  * number of encoded locks is stable, so copy to pagelist
3166                  */
3167                 struct_len = 2 * sizeof(u32) +
3168                             (num_fcntl_locks + num_flock_locks) *
3169                             sizeof(struct ceph_filelock);
3170                 rec.v2.flock_len = cpu_to_le32(struct_len);
3171
3172                 struct_len += sizeof(u32) + sizeof(rec.v2);
3173
3174                 if (struct_v >= 2)
3175                         struct_len += sizeof(u64); /* snap_follows */
3176
3177                 total_len += struct_len;
3178
3179                 if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
3180                         err = send_reconnect_partial(recon_state);
3181                         if (err)
3182                                 goto out_freeflocks;
3183                         pagelist = recon_state->pagelist;
3184                 }
3185
3186                 err = ceph_pagelist_reserve(pagelist, total_len);
3187                 if (err)
3188                         goto out_freeflocks;
3189
3190                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3191                 if (recon_state->msg_version >= 3) {
3192                         ceph_pagelist_encode_8(pagelist, struct_v);
3193                         ceph_pagelist_encode_8(pagelist, 1);
3194                         ceph_pagelist_encode_32(pagelist, struct_len);
3195                 }
3196                 ceph_pagelist_encode_string(pagelist, NULL, 0);
3197                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
3198                 ceph_locks_to_pagelist(flocks, pagelist,
3199                                        num_fcntl_locks, num_flock_locks);
3200                 if (struct_v >= 2)
3201                         ceph_pagelist_encode_64(pagelist, snap_follows);
3202 out_freeflocks:
3203                 kfree(flocks);
3204         } else {
3205                 u64 pathbase = 0;
3206                 int pathlen = 0;
3207                 char *path = NULL;
3208                 struct dentry *dentry;
3209
3210                 dentry = d_find_alias(inode);
3211                 if (dentry) {
3212                         path = ceph_mdsc_build_path(dentry,
3213                                                 &pathlen, &pathbase, 0);
3214                         dput(dentry);
3215                         if (IS_ERR(path)) {
3216                                 err = PTR_ERR(path);
3217                                 goto out_err;
3218                         }
3219                         rec.v1.pathbase = cpu_to_le64(pathbase);
3220                 }
3221
3222                 err = ceph_pagelist_reserve(pagelist,
3223                                             sizeof(u64) + sizeof(u32) +
3224                                             pathlen + sizeof(rec.v1));
3225                 if (err) {
3226                         goto out_freepath;
3227                 }
3228
3229                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3230                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3231                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
3232 out_freepath:
3233                 kfree(path);
3234         }
3235
3236 out_err:
3237         if (err >= 0)
3238                 recon_state->nr_caps++;
3239         return err;
3240 }
3241
3242 static int encode_snap_realms(struct ceph_mds_client *mdsc,
3243                               struct ceph_reconnect_state *recon_state)
3244 {
3245         struct rb_node *p;
3246         struct ceph_pagelist *pagelist = recon_state->pagelist;
3247         int err = 0;
3248
3249         if (recon_state->msg_version >= 4) {
3250                 err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
3251                 if (err < 0)
3252                         goto fail;
3253         }
3254
3255         /*
3256          * snaprealms.  we provide mds with the ino, seq (version), and
3257          * parent for all of our realms.  If the mds has any newer info,
3258          * it will tell us.
3259          */
3260         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3261                 struct ceph_snap_realm *realm =
3262                        rb_entry(p, struct ceph_snap_realm, node);
3263                 struct ceph_mds_snaprealm_reconnect sr_rec;
3264
3265                 if (recon_state->msg_version >= 4) {
3266                         size_t need = sizeof(u8) * 2 + sizeof(u32) +
3267                                       sizeof(sr_rec);
3268
3269                         if (pagelist->length + need > RECONNECT_MAX_SIZE) {
3270                                 err = send_reconnect_partial(recon_state);
3271                                 if (err)
3272                                         goto fail;
3273                                 pagelist = recon_state->pagelist;
3274                         }
3275
3276                         err = ceph_pagelist_reserve(pagelist, need);
3277                         if (err)
3278                                 goto fail;
3279
3280                         ceph_pagelist_encode_8(pagelist, 1);
3281                         ceph_pagelist_encode_8(pagelist, 1);
3282                         ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
3283                 }
3284
3285                 dout(" adding snap realm %llx seq %lld parent %llx\n",
3286                      realm->ino, realm->seq, realm->parent_ino);
3287                 sr_rec.ino = cpu_to_le64(realm->ino);
3288                 sr_rec.seq = cpu_to_le64(realm->seq);
3289                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
3290
3291                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3292                 if (err)
3293                         goto fail;
3294
3295                 recon_state->nr_realms++;
3296         }
3297 fail:
3298         return err;
3299 }
3300
3301
3302 /*
3303  * If an MDS fails and recovers, clients need to reconnect in order to
3304  * reestablish shared state.  This includes all caps issued through
3305  * this session _and_ the snap_realm hierarchy.  Because it's not
3306  * clear which snap realms the mds cares about, we send everything we
3307  * know about.. that ensures we'll then get any new info the
3308  * recovering MDS might have.
3309  *
3310  * This is a relatively heavyweight operation, but it's rare.
3311  *
3312  * called with mdsc->mutex held.
3313  */
3314 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
3315                                struct ceph_mds_session *session)
3316 {
3317         struct ceph_msg *reply;
3318         int mds = session->s_mds;
3319         int err = -ENOMEM;
3320         struct ceph_reconnect_state recon_state = {
3321                 .session = session,
3322         };
3323         LIST_HEAD(dispose);
3324
3325         pr_info("mds%d reconnect start\n", mds);
3326
3327         recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
3328         if (!recon_state.pagelist)
3329                 goto fail_nopagelist;
3330
3331         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3332         if (!reply)
3333                 goto fail_nomsg;
3334
3335         mutex_lock(&session->s_mutex);
3336         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
3337         session->s_seq = 0;
3338
3339         dout("session %p state %s\n", session,
3340              ceph_session_state_name(session->s_state));
3341
3342         spin_lock(&session->s_gen_ttl_lock);
3343         session->s_cap_gen++;
3344         spin_unlock(&session->s_gen_ttl_lock);
3345
3346         spin_lock(&session->s_cap_lock);
3347         /* don't know if session is readonly */
3348         session->s_readonly = 0;
3349         /*
3350          * notify __ceph_remove_cap() that we are composing cap reconnect.
3351          * If a cap get released before being added to the cap reconnect,
3352          * __ceph_remove_cap() should skip queuing cap release.
3353          */
3354         session->s_cap_reconnect = 1;
3355         /* drop old cap expires; we're about to reestablish that state */
3356         detach_cap_releases(session, &dispose);
3357         spin_unlock(&session->s_cap_lock);
3358         dispose_cap_releases(mdsc, &dispose);
3359
3360         /* trim unused caps to reduce MDS's cache rejoin time */
3361         if (mdsc->fsc->sb->s_root)
3362                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
3363
3364         ceph_con_close(&session->s_con);
3365         ceph_con_open(&session->s_con,
3366                       CEPH_ENTITY_TYPE_MDS, mds,
3367                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
3368
3369         /* replay unsafe requests */
3370         replay_unsafe_requests(mdsc, session);
3371
3372         ceph_early_kick_flushing_caps(mdsc, session);
3373
3374         down_read(&mdsc->snap_rwsem);
3375
3376         /* placeholder for nr_caps */
3377         err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
3378         if (err)
3379                 goto fail;
3380
3381         if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
3382                 recon_state.msg_version = 3;
3383                 recon_state.allow_multi = true;
3384         } else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
3385                 recon_state.msg_version = 3;
3386         } else {
3387                 recon_state.msg_version = 2;
3388         }
3389         /* trsaverse this session's caps */
3390         err = iterate_session_caps(session, encode_caps_cb, &recon_state);
3391
3392         spin_lock(&session->s_cap_lock);
3393         session->s_cap_reconnect = 0;
3394         spin_unlock(&session->s_cap_lock);
3395
3396         if (err < 0)
3397                 goto fail;
3398
3399         /* check if all realms can be encoded into current message */
3400         if (mdsc->num_snap_realms) {
3401                 size_t total_len =
3402                         recon_state.pagelist->length +
3403                         mdsc->num_snap_realms *
3404                         sizeof(struct ceph_mds_snaprealm_reconnect);
3405                 if (recon_state.msg_version >= 4) {
3406                         /* number of realms */
3407                         total_len += sizeof(u32);
3408                         /* version, compat_version and struct_len */
3409                         total_len += mdsc->num_snap_realms *
3410                                      (2 * sizeof(u8) + sizeof(u32));
3411                 }
3412                 if (total_len > RECONNECT_MAX_SIZE) {
3413                         if (!recon_state.allow_multi) {
3414                                 err = -ENOSPC;
3415                                 goto fail;
3416                         }
3417                         if (recon_state.nr_caps) {
3418                                 err = send_reconnect_partial(&recon_state);
3419                                 if (err)
3420                                         goto fail;
3421                         }
3422                         recon_state.msg_version = 5;
3423                 }
3424         }
3425
3426         err = encode_snap_realms(mdsc, &recon_state);
3427         if (err < 0)
3428                 goto fail;
3429
3430         if (recon_state.msg_version >= 5) {
3431                 err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
3432                 if (err < 0)
3433                         goto fail;
3434         }
3435
3436         if (recon_state.nr_caps || recon_state.nr_realms) {
3437                 struct page *page =
3438                         list_first_entry(&recon_state.pagelist->head,
3439                                         struct page, lru);
3440                 __le32 *addr = kmap_atomic(page);
3441                 if (recon_state.nr_caps) {
3442                         WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
3443                         *addr = cpu_to_le32(recon_state.nr_caps);
3444                 } else if (recon_state.msg_version >= 4) {
3445                         *(addr + 1) = cpu_to_le32(recon_state.nr_realms);
3446                 }
3447                 kunmap_atomic(addr);
3448         }
3449
3450         reply->hdr.version = cpu_to_le16(recon_state.msg_version);
3451         if (recon_state.msg_version >= 4)
3452                 reply->hdr.compat_version = cpu_to_le16(4);
3453
3454         reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
3455         ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
3456
3457         ceph_con_send(&session->s_con, reply);
3458
3459         mutex_unlock(&session->s_mutex);
3460
3461         mutex_lock(&mdsc->mutex);
3462         __wake_requests(mdsc, &session->s_waiting);
3463         mutex_unlock(&mdsc->mutex);
3464
3465         up_read(&mdsc->snap_rwsem);
3466         ceph_pagelist_release(recon_state.pagelist);
3467         return;
3468
3469 fail:
3470         ceph_msg_put(reply);
3471         up_read(&mdsc->snap_rwsem);
3472         mutex_unlock(&session->s_mutex);
3473 fail_nomsg:
3474         ceph_pagelist_release(recon_state.pagelist);
3475 fail_nopagelist:
3476         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3477         return;
3478 }
3479
3480
3481 /*
3482  * compare old and new mdsmaps, kicking requests
3483  * and closing out old connections as necessary
3484  *
3485  * called under mdsc->mutex.
3486  */
3487 static void check_new_map(struct ceph_mds_client *mdsc,
3488                           struct ceph_mdsmap *newmap,
3489                           struct ceph_mdsmap *oldmap)
3490 {
3491         int i;
3492         int oldstate, newstate;
3493         struct ceph_mds_session *s;
3494
3495         dout("check_new_map new %u old %u\n",
3496              newmap->m_epoch, oldmap->m_epoch);
3497
3498         for (i = 0; i < oldmap->m_num_mds && i < mdsc->max_sessions; i++) {
3499                 if (!mdsc->sessions[i])
3500                         continue;
3501                 s = mdsc->sessions[i];
3502                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3503                 newstate = ceph_mdsmap_get_state(newmap, i);
3504
3505                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3506                      i, ceph_mds_state_name(oldstate),
3507                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3508                      ceph_mds_state_name(newstate),
3509                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3510                      ceph_session_state_name(s->s_state));
3511
3512                 if (i >= newmap->m_num_mds ||
3513                     memcmp(ceph_mdsmap_get_addr(oldmap, i),
3514                            ceph_mdsmap_get_addr(newmap, i),
3515                            sizeof(struct ceph_entity_addr))) {
3516                         if (s->s_state == CEPH_MDS_SESSION_OPENING) {
3517                                 /* the session never opened, just close it
3518                                  * out now */
3519                                 get_session(s);
3520                                 __unregister_session(mdsc, s);
3521                                 __wake_requests(mdsc, &s->s_waiting);
3522                                 ceph_put_mds_session(s);
3523                         } else if (i >= newmap->m_num_mds) {
3524                                 /* force close session for stopped mds */
3525                                 get_session(s);
3526                                 __unregister_session(mdsc, s);
3527                                 __wake_requests(mdsc, &s->s_waiting);
3528                                 kick_requests(mdsc, i);
3529                                 mutex_unlock(&mdsc->mutex);
3530
3531                                 mutex_lock(&s->s_mutex);
3532                                 cleanup_session_requests(mdsc, s);
3533                                 remove_session_caps(s);
3534                                 mutex_unlock(&s->s_mutex);
3535
3536                                 ceph_put_mds_session(s);
3537
3538                                 mutex_lock(&mdsc->mutex);
3539                         } else {
3540                                 /* just close it */
3541                                 mutex_unlock(&mdsc->mutex);
3542                                 mutex_lock(&s->s_mutex);
3543                                 mutex_lock(&mdsc->mutex);
3544                                 ceph_con_close(&s->s_con);
3545                                 mutex_unlock(&s->s_mutex);
3546                                 s->s_state = CEPH_MDS_SESSION_RESTARTING;
3547                         }
3548                 } else if (oldstate == newstate) {
3549                         continue;  /* nothing new with this mds */
3550                 }
3551
3552                 /*
3553                  * send reconnect?
3554                  */
3555                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3556                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3557                         mutex_unlock(&mdsc->mutex);
3558                         send_mds_reconnect(mdsc, s);
3559                         mutex_lock(&mdsc->mutex);
3560                 }
3561
3562                 /*
3563                  * kick request on any mds that has gone active.
3564                  */
3565                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3566                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3567                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3568                             oldstate != CEPH_MDS_STATE_STARTING)
3569                                 pr_info("mds%d recovery completed\n", s->s_mds);
3570                         kick_requests(mdsc, i);
3571                         ceph_kick_flushing_caps(mdsc, s);
3572                         wake_up_session_caps(s, RECONNECT);
3573                 }
3574         }
3575
3576         for (i = 0; i < newmap->m_num_mds && i < mdsc->max_sessions; i++) {
3577                 s = mdsc->sessions[i];
3578                 if (!s)
3579                         continue;
3580                 if (!ceph_mdsmap_is_laggy(newmap, i))
3581                         continue;
3582                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3583                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3584                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3585                         dout(" connecting to export targets of laggy mds%d\n",
3586                              i);
3587                         __open_export_target_sessions(mdsc, s);
3588                 }
3589         }
3590 }
3591
3592
3593
3594 /*
3595  * leases
3596  */
3597
3598 /*
3599  * caller must hold session s_mutex, dentry->d_lock
3600  */
3601 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3602 {
3603         struct ceph_dentry_info *di = ceph_dentry(dentry);
3604
3605         ceph_put_mds_session(di->lease_session);
3606         di->lease_session = NULL;
3607 }
3608
3609 static void handle_lease(struct ceph_mds_client *mdsc,
3610                          struct ceph_mds_session *session,
3611                          struct ceph_msg *msg)
3612 {
3613         struct super_block *sb = mdsc->fsc->sb;
3614         struct inode *inode;
3615         struct dentry *parent, *dentry;
3616         struct ceph_dentry_info *di;
3617         int mds = session->s_mds;
3618         struct ceph_mds_lease *h = msg->front.iov_base;
3619         u32 seq;
3620         struct ceph_vino vino;
3621         struct qstr dname;
3622         int release = 0;
3623
3624         dout("handle_lease from mds%d\n", mds);
3625
3626         /* decode */
3627         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3628                 goto bad;
3629         vino.ino = le64_to_cpu(h->ino);
3630         vino.snap = CEPH_NOSNAP;
3631         seq = le32_to_cpu(h->seq);
3632         dname.len = get_unaligned_le32(h + 1);
3633         if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
3634                 goto bad;
3635         dname.name = (void *)(h + 1) + sizeof(u32);
3636
3637         /* lookup inode */
3638         inode = ceph_find_inode(sb, vino);
3639         dout("handle_lease %s, ino %llx %p %.*s\n",
3640              ceph_lease_op_name(h->action), vino.ino, inode,
3641              dname.len, dname.name);
3642
3643         mutex_lock(&session->s_mutex);
3644         session->s_seq++;
3645
3646         if (!inode) {
3647                 dout("handle_lease no inode %llx\n", vino.ino);
3648                 goto release;
3649         }
3650
3651         /* dentry */
3652         parent = d_find_alias(inode);
3653         if (!parent) {
3654                 dout("no parent dentry on inode %p\n", inode);
3655                 WARN_ON(1);
3656                 goto release;  /* hrm... */
3657         }
3658         dname.hash = full_name_hash(parent, dname.name, dname.len);
3659         dentry = d_lookup(parent, &dname);
3660         dput(parent);
3661         if (!dentry)
3662                 goto release;
3663
3664         spin_lock(&dentry->d_lock);
3665         di = ceph_dentry(dentry);
3666         switch (h->action) {
3667         case CEPH_MDS_LEASE_REVOKE:
3668                 if (di->lease_session == session) {
3669                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3670                                 h->seq = cpu_to_le32(di->lease_seq);
3671                         __ceph_mdsc_drop_dentry_lease(dentry);
3672                 }
3673                 release = 1;
3674                 break;
3675
3676         case CEPH_MDS_LEASE_RENEW:
3677                 if (di->lease_session == session &&
3678                     di->lease_gen == session->s_cap_gen &&
3679                     di->lease_renew_from &&
3680                     di->lease_renew_after == 0) {
3681                         unsigned long duration =
3682                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3683
3684                         di->lease_seq = seq;
3685                         di->time = di->lease_renew_from + duration;
3686                         di->lease_renew_after = di->lease_renew_from +
3687                                 (duration >> 1);
3688                         di->lease_renew_from = 0;
3689                 }
3690                 break;
3691         }
3692         spin_unlock(&dentry->d_lock);
3693         dput(dentry);
3694
3695         if (!release)
3696                 goto out;
3697
3698 release:
3699         /* let's just reuse the same message */
3700         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3701         ceph_msg_get(msg);
3702         ceph_con_send(&session->s_con, msg);
3703
3704 out:
3705         iput(inode);
3706         mutex_unlock(&session->s_mutex);
3707         return;
3708
3709 bad:
3710         pr_err("corrupt lease message\n");
3711         ceph_msg_dump(msg);
3712 }
3713
3714 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3715                               struct inode *inode,
3716                               struct dentry *dentry, char action,
3717                               u32 seq)
3718 {
3719         struct ceph_msg *msg;
3720         struct ceph_mds_lease *lease;
3721         int len = sizeof(*lease) + sizeof(u32);
3722         int dnamelen = 0;
3723
3724         dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
3725              inode, dentry, ceph_lease_op_name(action), session->s_mds);
3726         dnamelen = dentry->d_name.len;
3727         len += dnamelen;
3728
3729         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3730         if (!msg)
3731                 return;
3732         lease = msg->front.iov_base;
3733         lease->action = action;
3734         lease->ino = cpu_to_le64(ceph_vino(inode).ino);
3735         lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
3736         lease->seq = cpu_to_le32(seq);
3737         put_unaligned_le32(dnamelen, lease + 1);
3738         memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
3739
3740         /*
3741          * if this is a preemptive lease RELEASE, no need to
3742          * flush request stream, since the actual request will
3743          * soon follow.
3744          */
3745         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
3746
3747         ceph_con_send(&session->s_con, msg);
3748 }
3749
3750 /*
3751  * lock unlock sessions, to wait ongoing session activities
3752  */
3753 static void lock_unlock_sessions(struct ceph_mds_client *mdsc)
3754 {
3755         int i;
3756
3757         mutex_lock(&mdsc->mutex);
3758         for (i = 0; i < mdsc->max_sessions; i++) {
3759                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3760                 if (!s)
3761                         continue;
3762                 mutex_unlock(&mdsc->mutex);
3763                 mutex_lock(&s->s_mutex);
3764                 mutex_unlock(&s->s_mutex);
3765                 ceph_put_mds_session(s);
3766                 mutex_lock(&mdsc->mutex);
3767         }
3768         mutex_unlock(&mdsc->mutex);
3769 }
3770
3771
3772
3773 /*
3774  * delayed work -- periodically trim expired leases, renew caps with mds
3775  */
3776 static void schedule_delayed(struct ceph_mds_client *mdsc)
3777 {
3778         int delay = 5;
3779         unsigned hz = round_jiffies_relative(HZ * delay);
3780         schedule_delayed_work(&mdsc->delayed_work, hz);
3781 }
3782
3783 static void delayed_work(struct work_struct *work)
3784 {
3785         int i;
3786         struct ceph_mds_client *mdsc =
3787                 container_of(work, struct ceph_mds_client, delayed_work.work);
3788         int renew_interval;
3789         int renew_caps;
3790
3791         dout("mdsc delayed_work\n");
3792         ceph_check_delayed_caps(mdsc);
3793
3794         ceph_trim_snapid_map(mdsc);
3795
3796         mutex_lock(&mdsc->mutex);
3797         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3798         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3799                                    mdsc->last_renew_caps);
3800         if (renew_caps)
3801                 mdsc->last_renew_caps = jiffies;
3802
3803         for (i = 0; i < mdsc->max_sessions; i++) {
3804                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3805                 if (!s)
3806                         continue;
3807                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3808                         dout("resending session close request for mds%d\n",
3809                              s->s_mds);
3810                         request_close_session(mdsc, s);
3811                         ceph_put_mds_session(s);
3812                         continue;
3813                 }
3814                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3815                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3816                                 s->s_state = CEPH_MDS_SESSION_HUNG;
3817                                 pr_info("mds%d hung\n", s->s_mds);
3818                         }
3819                 }
3820                 if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3821                         /* this mds is failed or recovering, just wait */
3822                         ceph_put_mds_session(s);
3823                         continue;
3824                 }
3825                 mutex_unlock(&mdsc->mutex);
3826
3827                 mutex_lock(&s->s_mutex);
3828                 if (renew_caps)
3829                         send_renew_caps(mdsc, s);
3830                 else
3831                         ceph_con_keepalive(&s->s_con);
3832                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3833                     s->s_state == CEPH_MDS_SESSION_HUNG)
3834                         ceph_send_cap_releases(mdsc, s);
3835                 mutex_unlock(&s->s_mutex);
3836                 ceph_put_mds_session(s);
3837
3838                 mutex_lock(&mdsc->mutex);
3839         }
3840         mutex_unlock(&mdsc->mutex);
3841
3842         schedule_delayed(mdsc);
3843 }
3844
3845 int ceph_mdsc_init(struct ceph_fs_client *fsc)
3846
3847 {
3848         struct ceph_mds_client *mdsc;
3849
3850         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3851         if (!mdsc)
3852                 return -ENOMEM;
3853         mdsc->fsc = fsc;
3854         mutex_init(&mdsc->mutex);
3855         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3856         if (!mdsc->mdsmap) {
3857                 kfree(mdsc);
3858                 return -ENOMEM;
3859         }
3860
3861         fsc->mdsc = mdsc;
3862         init_completion(&mdsc->safe_umount_waiters);
3863         init_waitqueue_head(&mdsc->session_close_wq);
3864         INIT_LIST_HEAD(&mdsc->waiting_for_map);
3865         mdsc->sessions = NULL;
3866         atomic_set(&mdsc->num_sessions, 0);
3867         mdsc->max_sessions = 0;
3868         mdsc->stopping = 0;
3869         atomic64_set(&mdsc->quotarealms_count, 0);
3870         mdsc->last_snap_seq = 0;
3871         init_rwsem(&mdsc->snap_rwsem);
3872         mdsc->snap_realms = RB_ROOT;
3873         INIT_LIST_HEAD(&mdsc->snap_empty);
3874         mdsc->num_snap_realms = 0;
3875         spin_lock_init(&mdsc->snap_empty_lock);
3876         mdsc->last_tid = 0;
3877         mdsc->oldest_tid = 0;
3878         mdsc->request_tree = RB_ROOT;
3879         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3880         mdsc->last_renew_caps = jiffies;
3881         INIT_LIST_HEAD(&mdsc->cap_delay_list);
3882         spin_lock_init(&mdsc->cap_delay_lock);
3883         INIT_LIST_HEAD(&mdsc->snap_flush_list);
3884         spin_lock_init(&mdsc->snap_flush_lock);
3885         mdsc->last_cap_flush_tid = 1;
3886         INIT_LIST_HEAD(&mdsc->cap_flush_list);
3887         INIT_LIST_HEAD(&mdsc->cap_dirty);
3888         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3889         mdsc->num_cap_flushing = 0;
3890         spin_lock_init(&mdsc->cap_dirty_lock);
3891         init_waitqueue_head(&mdsc->cap_flushing_wq);
3892         spin_lock_init(&mdsc->dentry_lru_lock);
3893         INIT_LIST_HEAD(&mdsc->dentry_lru);
3894
3895         ceph_caps_init(mdsc);
3896         ceph_adjust_min_caps(mdsc, fsc->min_caps);
3897
3898         spin_lock_init(&mdsc->snapid_map_lock);
3899         mdsc->snapid_map_tree = RB_ROOT;
3900         INIT_LIST_HEAD(&mdsc->snapid_map_lru);
3901
3902         init_rwsem(&mdsc->pool_perm_rwsem);
3903         mdsc->pool_perm_tree = RB_ROOT;
3904
3905         strscpy(mdsc->nodename, utsname()->nodename,
3906                 sizeof(mdsc->nodename));
3907         return 0;
3908 }
3909
3910 /*
3911  * Wait for safe replies on open mds requests.  If we time out, drop
3912  * all requests from the tree to avoid dangling dentry refs.
3913  */
3914 static void wait_requests(struct ceph_mds_client *mdsc)
3915 {
3916         struct ceph_options *opts = mdsc->fsc->client->options;
3917         struct ceph_mds_request *req;
3918
3919         mutex_lock(&mdsc->mutex);
3920         if (__get_oldest_req(mdsc)) {
3921                 mutex_unlock(&mdsc->mutex);
3922
3923                 dout("wait_requests waiting for requests\n");
3924                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3925                                     ceph_timeout_jiffies(opts->mount_timeout));
3926
3927                 /* tear down remaining requests */
3928                 mutex_lock(&mdsc->mutex);
3929                 while ((req = __get_oldest_req(mdsc))) {
3930                         dout("wait_requests timed out on tid %llu\n",
3931                              req->r_tid);
3932                         __unregister_request(mdsc, req);
3933                 }
3934         }
3935         mutex_unlock(&mdsc->mutex);
3936         dout("wait_requests done\n");
3937 }
3938
3939 /*
3940  * called before mount is ro, and before dentries are torn down.
3941  * (hmm, does this still race with new lookups?)
3942  */
3943 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3944 {
3945         dout("pre_umount\n");
3946         mdsc->stopping = 1;
3947
3948         lock_unlock_sessions(mdsc);
3949         ceph_flush_dirty_caps(mdsc);
3950         wait_requests(mdsc);
3951
3952         /*
3953          * wait for reply handlers to drop their request refs and
3954          * their inode/dcache refs
3955          */
3956         ceph_msgr_flush();
3957 }
3958
3959 /*
3960  * wait for all write mds requests to flush.
3961  */
3962 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3963 {
3964         struct ceph_mds_request *req = NULL, *nextreq;
3965         struct rb_node *n;
3966
3967         mutex_lock(&mdsc->mutex);
3968         dout("wait_unsafe_requests want %lld\n", want_tid);
3969 restart:
3970         req = __get_oldest_req(mdsc);
3971         while (req && req->r_tid <= want_tid) {
3972                 /* find next request */
3973                 n = rb_next(&req->r_node);
3974                 if (n)
3975                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3976                 else
3977                         nextreq = NULL;
3978                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
3979                     (req->r_op & CEPH_MDS_OP_WRITE)) {
3980                         /* write op */
3981                         ceph_mdsc_get_request(req);
3982                         if (nextreq)
3983                                 ceph_mdsc_get_request(nextreq);
3984                         mutex_unlock(&mdsc->mutex);
3985                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3986                              req->r_tid, want_tid);
3987                         wait_for_completion(&req->r_safe_completion);
3988                         mutex_lock(&mdsc->mutex);
3989                         ceph_mdsc_put_request(req);
3990                         if (!nextreq)
3991                                 break;  /* next dne before, so we're done! */
3992                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
3993                                 /* next request was removed from tree */
3994                                 ceph_mdsc_put_request(nextreq);
3995                                 goto restart;
3996                         }
3997                         ceph_mdsc_put_request(nextreq);  /* won't go away */
3998                 }
3999                 req = nextreq;
4000         }
4001         mutex_unlock(&mdsc->mutex);
4002         dout("wait_unsafe_requests done\n");
4003 }
4004
4005 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
4006 {
4007         u64 want_tid, want_flush;
4008
4009         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4010                 return;
4011
4012         dout("sync\n");
4013         mutex_lock(&mdsc->mutex);
4014         want_tid = mdsc->last_tid;
4015         mutex_unlock(&mdsc->mutex);
4016
4017         ceph_flush_dirty_caps(mdsc);
4018         spin_lock(&mdsc->cap_dirty_lock);
4019         want_flush = mdsc->last_cap_flush_tid;
4020         if (!list_empty(&mdsc->cap_flush_list)) {
4021                 struct ceph_cap_flush *cf =
4022                         list_last_entry(&mdsc->cap_flush_list,
4023                                         struct ceph_cap_flush, g_list);
4024                 cf->wake = true;
4025         }
4026         spin_unlock(&mdsc->cap_dirty_lock);
4027
4028         dout("sync want tid %lld flush_seq %lld\n",
4029              want_tid, want_flush);
4030
4031         wait_unsafe_requests(mdsc, want_tid);
4032         wait_caps_flush(mdsc, want_flush);
4033 }
4034
4035 /*
4036  * true if all sessions are closed, or we force unmount
4037  */
4038 static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
4039 {
4040         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4041                 return true;
4042         return atomic_read(&mdsc->num_sessions) <= skipped;
4043 }
4044
4045 /*
4046  * called after sb is ro.
4047  */
4048 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
4049 {
4050         struct ceph_options *opts = mdsc->fsc->client->options;
4051         struct ceph_mds_session *session;
4052         int i;
4053         int skipped = 0;
4054
4055         dout("close_sessions\n");
4056
4057         /* close sessions */
4058         mutex_lock(&mdsc->mutex);
4059         for (i = 0; i < mdsc->max_sessions; i++) {
4060                 session = __ceph_lookup_mds_session(mdsc, i);
4061                 if (!session)
4062                         continue;
4063                 mutex_unlock(&mdsc->mutex);
4064                 mutex_lock(&session->s_mutex);
4065                 if (__close_session(mdsc, session) <= 0)
4066                         skipped++;
4067                 mutex_unlock(&session->s_mutex);
4068                 ceph_put_mds_session(session);
4069                 mutex_lock(&mdsc->mutex);
4070         }
4071         mutex_unlock(&mdsc->mutex);
4072
4073         dout("waiting for sessions to close\n");
4074         wait_event_timeout(mdsc->session_close_wq,
4075                            done_closing_sessions(mdsc, skipped),
4076                            ceph_timeout_jiffies(opts->mount_timeout));
4077
4078         /* tear down remaining sessions */
4079         mutex_lock(&mdsc->mutex);
4080         for (i = 0; i < mdsc->max_sessions; i++) {
4081                 if (mdsc->sessions[i]) {
4082                         session = get_session(mdsc->sessions[i]);
4083                         __unregister_session(mdsc, session);
4084                         mutex_unlock(&mdsc->mutex);
4085                         mutex_lock(&session->s_mutex);
4086                         remove_session_caps(session);
4087                         mutex_unlock(&session->s_mutex);
4088                         ceph_put_mds_session(session);
4089                         mutex_lock(&mdsc->mutex);
4090                 }
4091         }
4092         WARN_ON(!list_empty(&mdsc->cap_delay_list));
4093         mutex_unlock(&mdsc->mutex);
4094
4095         ceph_cleanup_snapid_map(mdsc);
4096
4097         ceph_cleanup_empty_realms(mdsc);
4098
4099         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4100
4101         dout("stopped\n");
4102 }
4103
4104 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
4105 {
4106         struct ceph_mds_session *session;
4107         int mds;
4108
4109         dout("force umount\n");
4110
4111         mutex_lock(&mdsc->mutex);
4112         for (mds = 0; mds < mdsc->max_sessions; mds++) {
4113                 session = __ceph_lookup_mds_session(mdsc, mds);
4114                 if (!session)
4115                         continue;
4116                 mutex_unlock(&mdsc->mutex);
4117                 mutex_lock(&session->s_mutex);
4118                 __close_session(mdsc, session);
4119                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
4120                         cleanup_session_requests(mdsc, session);
4121                         remove_session_caps(session);
4122                 }
4123                 mutex_unlock(&session->s_mutex);
4124                 ceph_put_mds_session(session);
4125                 mutex_lock(&mdsc->mutex);
4126                 kick_requests(mdsc, mds);
4127         }
4128         __wake_requests(mdsc, &mdsc->waiting_for_map);
4129         mutex_unlock(&mdsc->mutex);
4130 }
4131
4132 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
4133 {
4134         dout("stop\n");
4135         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4136         if (mdsc->mdsmap)
4137                 ceph_mdsmap_destroy(mdsc->mdsmap);
4138         kfree(mdsc->sessions);
4139         ceph_caps_finalize(mdsc);
4140         ceph_pool_perm_destroy(mdsc);
4141 }
4142
4143 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
4144 {
4145         struct ceph_mds_client *mdsc = fsc->mdsc;
4146         dout("mdsc_destroy %p\n", mdsc);
4147
4148         if (!mdsc)
4149                 return;
4150
4151         /* flush out any connection work with references to us */
4152         ceph_msgr_flush();
4153
4154         ceph_mdsc_stop(mdsc);
4155
4156         fsc->mdsc = NULL;
4157         kfree(mdsc);
4158         dout("mdsc_destroy %p done\n", mdsc);
4159 }
4160
4161 void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4162 {
4163         struct ceph_fs_client *fsc = mdsc->fsc;
4164         const char *mds_namespace = fsc->mount_options->mds_namespace;
4165         void *p = msg->front.iov_base;
4166         void *end = p + msg->front.iov_len;
4167         u32 epoch;
4168         u32 map_len;
4169         u32 num_fs;
4170         u32 mount_fscid = (u32)-1;
4171         u8 struct_v, struct_cv;
4172         int err = -EINVAL;
4173
4174         ceph_decode_need(&p, end, sizeof(u32), bad);
4175         epoch = ceph_decode_32(&p);
4176
4177         dout("handle_fsmap epoch %u\n", epoch);
4178
4179         ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4180         struct_v = ceph_decode_8(&p);
4181         struct_cv = ceph_decode_8(&p);
4182         map_len = ceph_decode_32(&p);
4183
4184         ceph_decode_need(&p, end, sizeof(u32) * 3, bad);
4185         p += sizeof(u32) * 2; /* skip epoch and legacy_client_fscid */
4186
4187         num_fs = ceph_decode_32(&p);
4188         while (num_fs-- > 0) {
4189                 void *info_p, *info_end;
4190                 u32 info_len;
4191                 u8 info_v, info_cv;
4192                 u32 fscid, namelen;
4193
4194                 ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4195                 info_v = ceph_decode_8(&p);
4196                 info_cv = ceph_decode_8(&p);
4197                 info_len = ceph_decode_32(&p);
4198                 ceph_decode_need(&p, end, info_len, bad);
4199                 info_p = p;
4200                 info_end = p + info_len;
4201                 p = info_end;
4202
4203                 ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
4204                 fscid = ceph_decode_32(&info_p);
4205                 namelen = ceph_decode_32(&info_p);
4206                 ceph_decode_need(&info_p, info_end, namelen, bad);
4207
4208                 if (mds_namespace &&
4209                     strlen(mds_namespace) == namelen &&
4210                     !strncmp(mds_namespace, (char *)info_p, namelen)) {
4211                         mount_fscid = fscid;
4212                         break;
4213                 }
4214         }
4215
4216         ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
4217         if (mount_fscid != (u32)-1) {
4218                 fsc->client->monc.fs_cluster_id = mount_fscid;
4219                 ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
4220                                    0, true);
4221                 ceph_monc_renew_subs(&fsc->client->monc);
4222         } else {
4223                 err = -ENOENT;
4224                 goto err_out;
4225         }
4226         return;
4227
4228 bad:
4229         pr_err("error decoding fsmap\n");
4230 err_out:
4231         mutex_lock(&mdsc->mutex);
4232         mdsc->mdsmap_err = err;
4233         __wake_requests(mdsc, &mdsc->waiting_for_map);
4234         mutex_unlock(&mdsc->mutex);
4235 }
4236
4237 /*
4238  * handle mds map update.
4239  */
4240 void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4241 {
4242         u32 epoch;
4243         u32 maplen;
4244         void *p = msg->front.iov_base;
4245         void *end = p + msg->front.iov_len;
4246         struct ceph_mdsmap *newmap, *oldmap;
4247         struct ceph_fsid fsid;
4248         int err = -EINVAL;
4249
4250         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
4251         ceph_decode_copy(&p, &fsid, sizeof(fsid));
4252         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
4253                 return;
4254         epoch = ceph_decode_32(&p);
4255         maplen = ceph_decode_32(&p);
4256         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
4257
4258         /* do we need it? */
4259         mutex_lock(&mdsc->mutex);
4260         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
4261                 dout("handle_map epoch %u <= our %u\n",
4262                      epoch, mdsc->mdsmap->m_epoch);
4263                 mutex_unlock(&mdsc->mutex);
4264                 return;
4265         }
4266
4267         newmap = ceph_mdsmap_decode(&p, end);
4268         if (IS_ERR(newmap)) {
4269                 err = PTR_ERR(newmap);
4270                 goto bad_unlock;
4271         }
4272
4273         /* swap into place */
4274         if (mdsc->mdsmap) {
4275                 oldmap = mdsc->mdsmap;
4276                 mdsc->mdsmap = newmap;
4277                 check_new_map(mdsc, newmap, oldmap);
4278                 ceph_mdsmap_destroy(oldmap);
4279         } else {
4280                 mdsc->mdsmap = newmap;  /* first mds map */
4281         }
4282         mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
4283                                         MAX_LFS_FILESIZE);
4284
4285         __wake_requests(mdsc, &mdsc->waiting_for_map);
4286         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
4287                           mdsc->mdsmap->m_epoch);
4288
4289         mutex_unlock(&mdsc->mutex);
4290         schedule_delayed(mdsc);
4291         return;
4292
4293 bad_unlock:
4294         mutex_unlock(&mdsc->mutex);
4295 bad:
4296         pr_err("error decoding mdsmap %d\n", err);
4297         return;
4298 }
4299
4300 static struct ceph_connection *con_get(struct ceph_connection *con)
4301 {
4302         struct ceph_mds_session *s = con->private;
4303
4304         if (get_session(s)) {
4305                 dout("mdsc con_get %p ok (%d)\n", s, refcount_read(&s->s_ref));
4306                 return con;
4307         }
4308         dout("mdsc con_get %p FAIL\n", s);
4309         return NULL;
4310 }
4311
4312 static void con_put(struct ceph_connection *con)
4313 {
4314         struct ceph_mds_session *s = con->private;
4315
4316         dout("mdsc con_put %p (%d)\n", s, refcount_read(&s->s_ref) - 1);
4317         ceph_put_mds_session(s);
4318 }
4319
4320 /*
4321  * if the client is unresponsive for long enough, the mds will kill
4322  * the session entirely.
4323  */
4324 static void peer_reset(struct ceph_connection *con)
4325 {
4326         struct ceph_mds_session *s = con->private;
4327         struct ceph_mds_client *mdsc = s->s_mdsc;
4328
4329         pr_warn("mds%d closed our session\n", s->s_mds);
4330         send_mds_reconnect(mdsc, s);
4331 }
4332
4333 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
4334 {
4335         struct ceph_mds_session *s = con->private;
4336         struct ceph_mds_client *mdsc = s->s_mdsc;
4337         int type = le16_to_cpu(msg->hdr.type);
4338
4339         mutex_lock(&mdsc->mutex);
4340         if (__verify_registered_session(mdsc, s) < 0) {
4341                 mutex_unlock(&mdsc->mutex);
4342                 goto out;
4343         }
4344         mutex_unlock(&mdsc->mutex);
4345
4346         switch (type) {
4347         case CEPH_MSG_MDS_MAP:
4348                 ceph_mdsc_handle_mdsmap(mdsc, msg);
4349                 break;
4350         case CEPH_MSG_FS_MAP_USER:
4351                 ceph_mdsc_handle_fsmap(mdsc, msg);
4352                 break;
4353         case CEPH_MSG_CLIENT_SESSION:
4354                 handle_session(s, msg);
4355                 break;
4356         case CEPH_MSG_CLIENT_REPLY:
4357                 handle_reply(s, msg);
4358                 break;
4359         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
4360                 handle_forward(mdsc, s, msg);
4361                 break;
4362         case CEPH_MSG_CLIENT_CAPS:
4363                 ceph_handle_caps(s, msg);
4364                 break;
4365         case CEPH_MSG_CLIENT_SNAP:
4366                 ceph_handle_snap(mdsc, s, msg);
4367                 break;
4368         case CEPH_MSG_CLIENT_LEASE:
4369                 handle_lease(mdsc, s, msg);
4370                 break;
4371         case CEPH_MSG_CLIENT_QUOTA:
4372                 ceph_handle_quota(mdsc, s, msg);
4373                 break;
4374
4375         default:
4376                 pr_err("received unknown message type %d %s\n", type,
4377                        ceph_msg_type_name(type));
4378         }
4379 out:
4380         ceph_msg_put(msg);
4381 }
4382
4383 /*
4384  * authentication
4385  */
4386
4387 /*
4388  * Note: returned pointer is the address of a structure that's
4389  * managed separately.  Caller must *not* attempt to free it.
4390  */
4391 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
4392                                         int *proto, int force_new)
4393 {
4394         struct ceph_mds_session *s = con->private;
4395         struct ceph_mds_client *mdsc = s->s_mdsc;
4396         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4397         struct ceph_auth_handshake *auth = &s->s_auth;
4398
4399         if (force_new && auth->authorizer) {
4400                 ceph_auth_destroy_authorizer(auth->authorizer);
4401                 auth->authorizer = NULL;
4402         }
4403         if (!auth->authorizer) {
4404                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4405                                                       auth);
4406                 if (ret)
4407                         return ERR_PTR(ret);
4408         } else {
4409                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4410                                                       auth);
4411                 if (ret)
4412                         return ERR_PTR(ret);
4413         }
4414         *proto = ac->protocol;
4415
4416         return auth;
4417 }
4418
4419 static int add_authorizer_challenge(struct ceph_connection *con,
4420                                     void *challenge_buf, int challenge_buf_len)
4421 {
4422         struct ceph_mds_session *s = con->private;
4423         struct ceph_mds_client *mdsc = s->s_mdsc;
4424         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4425
4426         return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
4427                                             challenge_buf, challenge_buf_len);
4428 }
4429
4430 static int verify_authorizer_reply(struct ceph_connection *con)
4431 {
4432         struct ceph_mds_session *s = con->private;
4433         struct ceph_mds_client *mdsc = s->s_mdsc;
4434         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4435
4436         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer);
4437 }
4438
4439 static int invalidate_authorizer(struct ceph_connection *con)
4440 {
4441         struct ceph_mds_session *s = con->private;
4442         struct ceph_mds_client *mdsc = s->s_mdsc;
4443         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4444
4445         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
4446
4447         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
4448 }
4449
4450 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
4451                                 struct ceph_msg_header *hdr, int *skip)
4452 {
4453         struct ceph_msg *msg;
4454         int type = (int) le16_to_cpu(hdr->type);
4455         int front_len = (int) le32_to_cpu(hdr->front_len);
4456
4457         if (con->in_msg)
4458                 return con->in_msg;
4459
4460         *skip = 0;
4461         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
4462         if (!msg) {
4463                 pr_err("unable to allocate msg type %d len %d\n",
4464                        type, front_len);
4465                 return NULL;
4466         }
4467
4468         return msg;
4469 }
4470
4471 static int mds_sign_message(struct ceph_msg *msg)
4472 {
4473        struct ceph_mds_session *s = msg->con->private;
4474        struct ceph_auth_handshake *auth = &s->s_auth;
4475
4476        return ceph_auth_sign_message(auth, msg);
4477 }
4478
4479 static int mds_check_message_signature(struct ceph_msg *msg)
4480 {
4481        struct ceph_mds_session *s = msg->con->private;
4482        struct ceph_auth_handshake *auth = &s->s_auth;
4483
4484        return ceph_auth_check_message_signature(auth, msg);
4485 }
4486
4487 static const struct ceph_connection_operations mds_con_ops = {
4488         .get = con_get,
4489         .put = con_put,
4490         .dispatch = dispatch,
4491         .get_authorizer = get_authorizer,
4492         .add_authorizer_challenge = add_authorizer_challenge,
4493         .verify_authorizer_reply = verify_authorizer_reply,
4494         .invalidate_authorizer = invalidate_authorizer,
4495         .peer_reset = peer_reset,
4496         .alloc_msg = mds_alloc_msg,
4497         .sign_message = mds_sign_message,
4498         .check_message_signature = mds_check_message_signature,
4499 };
4500
4501 /* eof */