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  47  * are no longer valid.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 static void ceph_cap_release_work(struct work_struct *work);
  61 static void ceph_cap_reclaim_work(struct work_struct *work);
  62
  63 static const struct ceph_connection_operations mds_con_ops;
  64
  65
  66 /*
  67  * mds reply parsing
  68  */
  69
  70 static int parse_reply_info_quota(void **p, void *end,
  71                                   struct ceph_mds_reply_info_in *info)
  72 {
  73         u8 struct_v, struct_compat;
  74         u32 struct_len;
  75
  76         ceph_decode_8_safe(p, end, struct_v, bad);
  77         ceph_decode_8_safe(p, end, struct_compat, bad);
  78         /* struct_v is expected to be >= 1. we only
  79          * understand encoding with struct_compat == 1. */
  80         if (!struct_v || struct_compat != 1)
  81                 goto bad;
  82         ceph_decode_32_safe(p, end, struct_len, bad);
  83         ceph_decode_need(p, end, struct_len, bad);
  84         end = *p + struct_len;
  85         ceph_decode_64_safe(p, end, info->max_bytes, bad);
  86         ceph_decode_64_safe(p, end, info->max_files, bad);
  87         *p = end;
  88         return 0;
  89 bad:
  90         return -EIO;
  91 }
  92
  93 /*
  94  * parse individual inode info
  95  */
  96 static int parse_reply_info_in(void **p, void *end,
  97                                struct ceph_mds_reply_info_in *info,
  98                                u64 features)
  99 {
 100         int err = 0;
 101         u8 struct_v = 0;
 102
 103         if (features == (u64)-1) {
 104                 u32 struct_len;
 105                 u8 struct_compat;
 106                 ceph_decode_8_safe(p, end, struct_v, bad);
 107                 ceph_decode_8_safe(p, end, struct_compat, bad);
 108                 /* struct_v is expected to be >= 1. we only understand
 109                  * encoding with struct_compat == 1. */
 110                 if (!struct_v || struct_compat != 1)
 111                         goto bad;
 112                 ceph_decode_32_safe(p, end, struct_len, bad);
 113                 ceph_decode_need(p, end, struct_len, bad);
 114                 end = *p + struct_len;
 115         }
 116
 117         ceph_decode_need(p, end, sizeof(struct ceph_mds_reply_inode), bad);
 118         info->in = *p;
 119         *p += sizeof(struct ceph_mds_reply_inode) +
 120                 sizeof(*info->in->fragtree.splits) *
 121                 le32_to_cpu(info->in->fragtree.nsplits);
 122
 123         ceph_decode_32_safe(p, end, info->symlink_len, bad);
 124         ceph_decode_need(p, end, info->symlink_len, bad);
 125         info->symlink = *p;
 126         *p += info->symlink_len;
 127
 128         ceph_decode_copy_safe(p, end, &info->dir_layout,
 129                               sizeof(info->dir_layout), bad);
 130         ceph_decode_32_safe(p, end, info->xattr_len, bad);
 131         ceph_decode_need(p, end, info->xattr_len, bad);
 132         info->xattr_data = *p;
 133         *p += info->xattr_len;
 134
 135         if (features == (u64)-1) {
 136                 /* inline data */
 137                 ceph_decode_64_safe(p, end, info->inline_version, bad);
 138                 ceph_decode_32_safe(p, end, info->inline_len, bad);
 139                 ceph_decode_need(p, end, info->inline_len, bad);
 140                 info->inline_data = *p;
 141                 *p += info->inline_len;
 142                 /* quota */
 143                 err = parse_reply_info_quota(p, end, info);
 144                 if (err < 0)
 145                         goto out_bad;
 146                 /* pool namespace */
 147                 ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 148                 if (info->pool_ns_len > 0) {
 149                         ceph_decode_need(p, end, info->pool_ns_len, bad);
 150                         info->pool_ns_data = *p;
 151                         *p += info->pool_ns_len;
 152                 }
 153
 154                 /* btime */
 155                 ceph_decode_need(p, end, sizeof(info->btime), bad);
 156                 ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 157
 158                 /* change attribute */
 159                 ceph_decode_64_safe(p, end, info->change_attr, bad);
 160
 161                 /* dir pin */
 162                 if (struct_v >= 2) {
 163                         ceph_decode_32_safe(p, end, info->dir_pin, bad);
 164                 } else {
 165                         info->dir_pin = -ENODATA;
 166                 }
 167
 168                 /* snapshot birth time, remains zero for v<=2 */
 169                 if (struct_v >= 3) {
 170                         ceph_decode_need(p, end, sizeof(info->snap_btime), bad);
 171                         ceph_decode_copy(p, &info->snap_btime,
 172                                          sizeof(info->snap_btime));
 173                 } else {
 174                         memset(&info->snap_btime, 0, sizeof(info->snap_btime));
 175                 }
 176
 177                 *p = end;
 178         } else {
 179                 if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
 180                         ceph_decode_64_safe(p, end, info->inline_version, bad);
 181                         ceph_decode_32_safe(p, end, info->inline_len, bad);
 182                         ceph_decode_need(p, end, info->inline_len, bad);
 183                         info->inline_data = *p;
 184                         *p += info->inline_len;
 185                 } else
 186                         info->inline_version = CEPH_INLINE_NONE;
 187
 188                 if (features & CEPH_FEATURE_MDS_QUOTA) {
 189                         err = parse_reply_info_quota(p, end, info);
 190                         if (err < 0)
 191                                 goto out_bad;
 192                 } else {
 193                         info->max_bytes = 0;
 194                         info->max_files = 0;
 195                 }
 196
 197                 info->pool_ns_len = 0;
 198                 info->pool_ns_data = NULL;
 199                 if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 200                         ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 201                         if (info->pool_ns_len > 0) {
 202                                 ceph_decode_need(p, end, info->pool_ns_len, bad);
 203                                 info->pool_ns_data = *p;
 204                                 *p += info->pool_ns_len;
 205                         }
 206                 }
 207
 208                 if (features & CEPH_FEATURE_FS_BTIME) {
 209                         ceph_decode_need(p, end, sizeof(info->btime), bad);
 210                         ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 211                         ceph_decode_64_safe(p, end, info->change_attr, bad);
 212                 }
 213
 214                 info->dir_pin = -ENODATA;
 215                 /* info->snap_btime remains zero */
 216         }
 217         return 0;
 218 bad:
 219         err = -EIO;
 220 out_bad:
 221         return err;
 222 }
 223
 224 static int parse_reply_info_dir(void **p, void *end,
 225                                 struct ceph_mds_reply_dirfrag **dirfrag,
 226                                 u64 features)
 227 {
 228         if (features == (u64)-1) {
 229                 u8 struct_v, struct_compat;
 230                 u32 struct_len;
 231                 ceph_decode_8_safe(p, end, struct_v, bad);
 232                 ceph_decode_8_safe(p, end, struct_compat, bad);
 233                 /* struct_v is expected to be >= 1. we only understand
 234                  * encoding whose struct_compat == 1. */
 235                 if (!struct_v || struct_compat != 1)
 236                         goto bad;
 237                 ceph_decode_32_safe(p, end, struct_len, bad);
 238                 ceph_decode_need(p, end, struct_len, bad);
 239                 end = *p + struct_len;
 240         }
 241
 242         ceph_decode_need(p, end, sizeof(**dirfrag), bad);
 243         *dirfrag = *p;
 244         *p += sizeof(**dirfrag) + sizeof(u32) * le32_to_cpu((*dirfrag)->ndist);
 245         if (unlikely(*p > end))
 246                 goto bad;
 247         if (features == (u64)-1)
 248                 *p = end;
 249         return 0;
 250 bad:
 251         return -EIO;
 252 }
 253
 254 static int parse_reply_info_lease(void **p, void *end,
 255                                   struct ceph_mds_reply_lease **lease,
 256                                   u64 features)
 257 {
 258         if (features == (u64)-1) {
 259                 u8 struct_v, struct_compat;
 260                 u32 struct_len;
 261                 ceph_decode_8_safe(p, end, struct_v, bad);
 262                 ceph_decode_8_safe(p, end, struct_compat, bad);
 263                 /* struct_v is expected to be >= 1. we only understand
 264                  * encoding whose struct_compat == 1. */
 265                 if (!struct_v || struct_compat != 1)
 266                         goto bad;
 267                 ceph_decode_32_safe(p, end, struct_len, bad);
 268                 ceph_decode_need(p, end, struct_len, bad);
 269                 end = *p + struct_len;
 270         }
 271
 272         ceph_decode_need(p, end, sizeof(**lease), bad);
 273         *lease = *p;
 274         *p += sizeof(**lease);
 275         if (features == (u64)-1)
 276                 *p = end;
 277         return 0;
 278 bad:
 279         return -EIO;
 280 }
 281
 282 /*
 283  * parse a normal reply, which may contain a (dir+)dentry and/or a
 284  * target inode.
 285  */
 286 static int parse_reply_info_trace(void **p, void *end,
 287                                   struct ceph_mds_reply_info_parsed *info,
 288                                   u64 features)
 289 {
 290         int err;
 291
 292         if (info->head->is_dentry) {
 293                 err = parse_reply_info_in(p, end, &info->diri, features);
 294                 if (err < 0)
 295                         goto out_bad;
 296
 297                 err = parse_reply_info_dir(p, end, &info->dirfrag, features);
 298                 if (err < 0)
 299                         goto out_bad;
 300
 301                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 302                 ceph_decode_need(p, end, info->dname_len, bad);
 303                 info->dname = *p;
 304                 *p += info->dname_len;
 305
 306                 err = parse_reply_info_lease(p, end, &info->dlease, features);
 307                 if (err < 0)
 308                         goto out_bad;
 309         }
 310
 311         if (info->head->is_target) {
 312                 err = parse_reply_info_in(p, end, &info->targeti, features);
 313                 if (err < 0)
 314                         goto out_bad;
 315         }
 316
 317         if (unlikely(*p != end))
 318                 goto bad;
 319         return 0;
 320
 321 bad:
 322         err = -EIO;
 323 out_bad:
 324         pr_err("problem parsing mds trace %d\n", err);
 325         return err;
 326 }
 327
 328 /*
 329  * parse readdir results
 330  */
 331 static int parse_reply_info_readdir(void **p, void *end,
 332                                 struct ceph_mds_reply_info_parsed *info,
 333                                 u64 features)
 334 {
 335         u32 num, i = 0;
 336         int err;
 337
 338         err = parse_reply_info_dir(p, end, &info->dir_dir, features);
 339         if (err < 0)
 340                 goto out_bad;
 341
 342         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 343         num = ceph_decode_32(p);
 344         {
 345                 u16 flags = ceph_decode_16(p);
 346                 info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 347                 info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 348                 info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 349                 info->offset_hash = !!(flags & CEPH_READDIR_OFFSET_HASH);
 350         }
 351         if (num == 0)
 352                 goto done;
 353
 354         BUG_ON(!info->dir_entries);
 355         if ((unsigned long)(info->dir_entries + num) >
 356             (unsigned long)info->dir_entries + info->dir_buf_size) {
 357                 pr_err("dir contents are larger than expected\n");
 358                 WARN_ON(1);
 359                 goto bad;
 360         }
 361
 362         info->dir_nr = num;
 363         while (num) {
 364                 struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 365                 /* dentry */
 366                 ceph_decode_32_safe(p, end, rde->name_len, bad);
 367                 ceph_decode_need(p, end, rde->name_len, bad);
 368                 rde->name = *p;
 369                 *p += rde->name_len;
 370                 dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 371
 372                 /* dentry lease */
 373                 err = parse_reply_info_lease(p, end, &rde->lease, features);
 374                 if (err)
 375                         goto out_bad;
 376                 /* inode */
 377                 err = parse_reply_info_in(p, end, &rde->inode, features);
 378                 if (err < 0)
 379                         goto out_bad;
 380                 /* ceph_readdir_prepopulate() will update it */
 381                 rde->offset = 0;
 382                 i++;
 383                 num--;
 384         }
 385
 386 done:
 387         /* Skip over any unrecognized fields */
 388         *p = end;
 389         return 0;
 390
 391 bad:
 392         err = -EIO;
 393 out_bad:
 394         pr_err("problem parsing dir contents %d\n", err);
 395         return err;
 396 }
 397
 398 /*
 399  * parse fcntl F_GETLK results
 400  */
 401 static int parse_reply_info_filelock(void **p, void *end,
 402                                      struct ceph_mds_reply_info_parsed *info,
 403                                      u64 features)
 404 {
 405         if (*p + sizeof(*info->filelock_reply) > end)
 406                 goto bad;
 407
 408         info->filelock_reply = *p;
 409
 410         /* Skip over any unrecognized fields */
 411         *p = end;
 412         return 0;
 413 bad:
 414         return -EIO;
 415 }
 416
 417 /*
 418  * parse create results
 419  */
 420 static int parse_reply_info_create(void **p, void *end,
 421                                   struct ceph_mds_reply_info_parsed *info,
 422                                   u64 features)
 423 {
 424         if (features == (u64)-1 ||
 425             (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
 426                 /* Malformed reply? */
 427                 if (*p == end) {
 428                         info->has_create_ino = false;
 429                 } else {
 430                         info->has_create_ino = true;
 431                         ceph_decode_64_safe(p, end, info->ino, bad);
 432                 }
 433         } else {
 434                 if (*p != end)
 435                         goto bad;
 436         }
 437
 438         /* Skip over any unrecognized fields */
 439         *p = end;
 440         return 0;
 441 bad:
 442         return -EIO;
 443 }
 444
 445 /*
 446  * parse extra results
 447  */
 448 static int parse_reply_info_extra(void **p, void *end,
 449                                   struct ceph_mds_reply_info_parsed *info,
 450                                   u64 features)
 451 {
 452         u32 op = le32_to_cpu(info->head->op);
 453
 454         if (op == CEPH_MDS_OP_GETFILELOCK)
 455                 return parse_reply_info_filelock(p, end, info, features);
 456         else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 457                 return parse_reply_info_readdir(p, end, info, features);
 458         else if (op == CEPH_MDS_OP_CREATE)
 459                 return parse_reply_info_create(p, end, info, features);
 460         else
 461                 return -EIO;
 462 }
 463
 464 /*
 465  * parse entire mds reply
 466  */
 467 static int parse_reply_info(struct ceph_msg *msg,
 468                             struct ceph_mds_reply_info_parsed *info,
 469                             u64 features)
 470 {
 471         void *p, *end;
 472         u32 len;
 473         int err;
 474
 475         info->head = msg->front.iov_base;
 476         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 477         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 478
 479         /* trace */
 480         ceph_decode_32_safe(&p, end, len, bad);
 481         if (len > 0) {
 482                 ceph_decode_need(&p, end, len, bad);
 483                 err = parse_reply_info_trace(&p, p+len, info, features);
 484                 if (err < 0)
 485                         goto out_bad;
 486         }
 487
 488         /* extra */
 489         ceph_decode_32_safe(&p, end, len, bad);
 490         if (len > 0) {
 491                 ceph_decode_need(&p, end, len, bad);
 492                 err = parse_reply_info_extra(&p, p+len, info, features);
 493                 if (err < 0)
 494                         goto out_bad;
 495         }
 496
 497         /* snap blob */
 498         ceph_decode_32_safe(&p, end, len, bad);
 499         info->snapblob_len = len;
 500         info->snapblob = p;
 501         p += len;
 502
 503         if (p != end)
 504                 goto bad;
 505         return 0;
 506
 507 bad:
 508         err = -EIO;
 509 out_bad:
 510         pr_err("mds parse_reply err %d\n", err);
 511         return err;
 512 }
 513
 514 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 515 {
 516         if (!info->dir_entries)
 517                 return;
 518         free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 519 }
 520
 521
 522 /*
 523  * sessions
 524  */
 525 const char *ceph_session_state_name(int s)
 526 {
 527         switch (s) {
 528         case CEPH_MDS_SESSION_NEW: return "new";
 529         case CEPH_MDS_SESSION_OPENING: return "opening";
 530         case CEPH_MDS_SESSION_OPEN: return "open";
 531         case CEPH_MDS_SESSION_HUNG: return "hung";
 532         case CEPH_MDS_SESSION_CLOSING: return "closing";
 533         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 534         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 535         case CEPH_MDS_SESSION_REJECTED: return "rejected";
 536         default: return "???";
 537         }
 538 }
 539
 540 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 541 {
 542         if (refcount_inc_not_zero(&s->s_ref)) {
 543                 dout("mdsc get_session %p %d -> %d\n", s,
 544                      refcount_read(&s->s_ref)-1, refcount_read(&s->s_ref));
 545                 return s;
 546         } else {
 547                 dout("mdsc get_session %p 0 -- FAIL\n", s);
 548                 return NULL;
 549         }
 550 }
 551
 552 void ceph_put_mds_session(struct ceph_mds_session *s)
 553 {
 554         dout("mdsc put_session %p %d -> %d\n", s,
 555              refcount_read(&s->s_ref), refcount_read(&s->s_ref)-1);
 556         if (refcount_dec_and_test(&s->s_ref)) {
 557                 if (s->s_auth.authorizer)
 558                         ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 559                 kfree(s);
 560         }
 561 }
 562
 563 /*
 564  * called under mdsc->mutex
 565  */
 566 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 567                                                    int mds)
 568 {
 569         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 570                 return NULL;
 571         return get_session(mdsc->sessions[mds]);
 572 }
 573
 574 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 575 {
 576         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 577                 return false;
 578         else
 579                 return true;
 580 }
 581
 582 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 583                                        struct ceph_mds_session *s)
 584 {
 585         if (s->s_mds >= mdsc->max_sessions ||
 586             mdsc->sessions[s->s_mds] != s)
 587                 return -ENOENT;
 588         return 0;
 589 }
 590
 591 /*
 592  * create+register a new session for given mds.
 593  * called under mdsc->mutex.
 594  */
 595 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 596                                                  int mds)
 597 {
 598         struct ceph_mds_session *s;
 599
 600         if (mds >= mdsc->mdsmap->m_num_mds)
 601                 return ERR_PTR(-EINVAL);
 602
 603         s = kzalloc(sizeof(*s), GFP_NOFS);
 604         if (!s)
 605                 return ERR_PTR(-ENOMEM);
 606
 607         if (mds >= mdsc->max_sessions) {
 608                 int newmax = 1 << get_count_order(mds + 1);
 609                 struct ceph_mds_session **sa;
 610
 611                 dout("%s: realloc to %d\n", __func__, newmax);
 612                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 613                 if (!sa)
 614                         goto fail_realloc;
 615                 if (mdsc->sessions) {
 616                         memcpy(sa, mdsc->sessions,
 617                                mdsc->max_sessions * sizeof(void *));
 618                         kfree(mdsc->sessions);
 619                 }
 620                 mdsc->sessions = sa;
 621                 mdsc->max_sessions = newmax;
 622         }
 623
 624         dout("%s: mds%d\n", __func__, mds);
 625         s->s_mdsc = mdsc;
 626         s->s_mds = mds;
 627         s->s_state = CEPH_MDS_SESSION_NEW;
 628         s->s_ttl = 0;
 629         s->s_seq = 0;
 630         mutex_init(&s->s_mutex);
 631
 632         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 633
 634         spin_lock_init(&s->s_gen_ttl_lock);
 635         s->s_cap_gen = 1;
 636         s->s_cap_ttl = jiffies - 1;
 637
 638         spin_lock_init(&s->s_cap_lock);
 639         s->s_renew_requested = 0;
 640         s->s_renew_seq = 0;
 641         INIT_LIST_HEAD(&s->s_caps);
 642         s->s_nr_caps = 0;
 643         refcount_set(&s->s_ref, 1);
 644         INIT_LIST_HEAD(&s->s_waiting);
 645         INIT_LIST_HEAD(&s->s_unsafe);
 646         s->s_num_cap_releases = 0;
 647         s->s_cap_reconnect = 0;
 648         s->s_cap_iterator = NULL;
 649         INIT_LIST_HEAD(&s->s_cap_releases);
 650         INIT_WORK(&s->s_cap_release_work, ceph_cap_release_work);
 651
 652         INIT_LIST_HEAD(&s->s_cap_flushing);
 653
 654         mdsc->sessions[mds] = s;
 655         atomic_inc(&mdsc->num_sessions);
 656         refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 657
 658         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 659                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 660
 661         return s;
 662
 663 fail_realloc:
 664         kfree(s);
 665         return ERR_PTR(-ENOMEM);
 666 }
 667
 668 /*
 669  * called under mdsc->mutex
 670  */
 671 static void __unregister_session(struct ceph_mds_client *mdsc,
 672                                struct ceph_mds_session *s)
 673 {
 674         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 675         BUG_ON(mdsc->sessions[s->s_mds] != s);
 676         mdsc->sessions[s->s_mds] = NULL;
 677         s->s_state = 0;
 678         ceph_con_close(&s->s_con);
 679         ceph_put_mds_session(s);
 680         atomic_dec(&mdsc->num_sessions);
 681 }
 682
 683 /*
 684  * drop session refs in request.
 685  *
 686  * should be last request ref, or hold mdsc->mutex
 687  */
 688 static void put_request_session(struct ceph_mds_request *req)
 689 {
 690         if (req->r_session) {
 691                 ceph_put_mds_session(req->r_session);
 692                 req->r_session = NULL;
 693         }
 694 }
 695
 696 void ceph_mdsc_release_request(struct kref *kref)
 697 {
 698         struct ceph_mds_request *req = container_of(kref,
 699                                                     struct ceph_mds_request,
 700                                                     r_kref);
 701         destroy_reply_info(&req->r_reply_info);
 702         if (req->r_request)
 703                 ceph_msg_put(req->r_request);
 704         if (req->r_reply)
 705                 ceph_msg_put(req->r_reply);
 706         if (req->r_inode) {
 707                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 708                 /* avoid calling iput_final() in mds dispatch threads */
 709                 ceph_async_iput(req->r_inode);
 710         }
 711         if (req->r_parent) {
 712                 ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
 713                 ceph_async_iput(req->r_parent);
 714         }
 715         ceph_async_iput(req->r_target_inode);
 716         if (req->r_dentry)
 717                 dput(req->r_dentry);
 718         if (req->r_old_dentry)
 719                 dput(req->r_old_dentry);
 720         if (req->r_old_dentry_dir) {
 721                 /*
 722                  * track (and drop pins for) r_old_dentry_dir
 723                  * separately, since r_old_dentry's d_parent may have
 724                  * changed between the dir mutex being dropped and
 725                  * this request being freed.
 726                  */
 727                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 728                                   CEPH_CAP_PIN);
 729                 ceph_async_iput(req->r_old_dentry_dir);
 730         }
 731         kfree(req->r_path1);
 732         kfree(req->r_path2);
 733         if (req->r_pagelist)
 734                 ceph_pagelist_release(req->r_pagelist);
 735         put_request_session(req);
 736         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 737         WARN_ON_ONCE(!list_empty(&req->r_wait));
 738         kfree(req);
 739 }
 740
 741 DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 742
 743 /*
 744  * lookup session, bump ref if found.
 745  *
 746  * called under mdsc->mutex.
 747  */
 748 static struct ceph_mds_request *
 749 lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 750 {
 751         struct ceph_mds_request *req;
 752
 753         req = lookup_request(&mdsc->request_tree, tid);
 754         if (req)
 755                 ceph_mdsc_get_request(req);
 756
 757         return req;
 758 }
 759
 760 /*
 761  * Register an in-flight request, and assign a tid.  Link to directory
 762  * are modifying (if any).
 763  *
 764  * Called under mdsc->mutex.
 765  */
 766 static void __register_request(struct ceph_mds_client *mdsc,
 767                                struct ceph_mds_request *req,
 768                                struct inode *dir)
 769 {
 770         int ret = 0;
 771
 772         req->r_tid = ++mdsc->last_tid;
 773         if (req->r_num_caps) {
 774                 ret = ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 775                                         req->r_num_caps);
 776                 if (ret < 0) {
 777                         pr_err("__register_request %p "
 778                                "failed to reserve caps: %d\n", req, ret);
 779                         /* set req->r_err to fail early from __do_request */
 780                         req->r_err = ret;
 781                         return;
 782                 }
 783         }
 784         dout("__register_request %p tid %lld\n", req, req->r_tid);
 785         ceph_mdsc_get_request(req);
 786         insert_request(&mdsc->request_tree, req);
 787
 788         req->r_uid = current_fsuid();
 789         req->r_gid = current_fsgid();
 790
 791         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 792                 mdsc->oldest_tid = req->r_tid;
 793
 794         if (dir) {
 795                 ihold(dir);
 796                 req->r_unsafe_dir = dir;
 797         }
 798 }
 799
 800 static void __unregister_request(struct ceph_mds_client *mdsc,
 801                                  struct ceph_mds_request *req)
 802 {
 803         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 804
 805         /* Never leave an unregistered request on an unsafe list! */
 806         list_del_init(&req->r_unsafe_item);
 807
 808         if (req->r_tid == mdsc->oldest_tid) {
 809                 struct rb_node *p = rb_next(&req->r_node);
 810                 mdsc->oldest_tid = 0;
 811                 while (p) {
 812                         struct ceph_mds_request *next_req =
 813                                 rb_entry(p, struct ceph_mds_request, r_node);
 814                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 815                                 mdsc->oldest_tid = next_req->r_tid;
 816                                 break;
 817                         }
 818                         p = rb_next(p);
 819                 }
 820         }
 821
 822         erase_request(&mdsc->request_tree, req);
 823
 824         if (req->r_unsafe_dir  &&
 825             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 826                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 827                 spin_lock(&ci->i_unsafe_lock);
 828                 list_del_init(&req->r_unsafe_dir_item);
 829                 spin_unlock(&ci->i_unsafe_lock);
 830         }
 831         if (req->r_target_inode &&
 832             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 833                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 834                 spin_lock(&ci->i_unsafe_lock);
 835                 list_del_init(&req->r_unsafe_target_item);
 836                 spin_unlock(&ci->i_unsafe_lock);
 837         }
 838
 839         if (req->r_unsafe_dir) {
 840                 /* avoid calling iput_final() in mds dispatch threads */
 841                 ceph_async_iput(req->r_unsafe_dir);
 842                 req->r_unsafe_dir = NULL;
 843         }
 844
 845         complete_all(&req->r_safe_completion);
 846
 847         ceph_mdsc_put_request(req);
 848 }
 849
 850 /*
 851  * Walk back up the dentry tree until we hit a dentry representing a
 852  * non-snapshot inode. We do this using the rcu_read_lock (which must be held
 853  * when calling this) to ensure that the objects won't disappear while we're
 854  * working with them. Once we hit a candidate dentry, we attempt to take a
 855  * reference to it, and return that as the result.
 856  */
 857 static struct inode *get_nonsnap_parent(struct dentry *dentry)
 858 {
 859         struct inode *inode = NULL;
 860
 861         while (dentry && !IS_ROOT(dentry)) {
 862                 inode = d_inode_rcu(dentry);
 863                 if (!inode || ceph_snap(inode) == CEPH_NOSNAP)
 864                         break;
 865                 dentry = dentry->d_parent;
 866         }
 867         if (inode)
 868                 inode = igrab(inode);
 869         return inode;
 870 }
 871
 872 /*
 873  * Choose mds to send request to next.  If there is a hint set in the
 874  * request (e.g., due to a prior forward hint from the mds), use that.
 875  * Otherwise, consult frag tree and/or caps to identify the
 876  * appropriate mds.  If all else fails, choose randomly.
 877  *
 878  * Called under mdsc->mutex.
 879  */
 880 static int __choose_mds(struct ceph_mds_client *mdsc,
 881                         struct ceph_mds_request *req)
 882 {
 883         struct inode *inode;
 884         struct ceph_inode_info *ci;
 885         struct ceph_cap *cap;
 886         int mode = req->r_direct_mode;
 887         int mds = -1;
 888         u32 hash = req->r_direct_hash;
 889         bool is_hash = test_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
 890
 891         /*
 892          * is there a specific mds we should try?  ignore hint if we have
 893          * no session and the mds is not up (active or recovering).
 894          */
 895         if (req->r_resend_mds >= 0 &&
 896             (__have_session(mdsc, req->r_resend_mds) ||
 897              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 898                 dout("choose_mds using resend_mds mds%d\n",
 899                      req->r_resend_mds);
 900                 return req->r_resend_mds;
 901         }
 902
 903         if (mode == USE_RANDOM_MDS)
 904                 goto random;
 905
 906         inode = NULL;
 907         if (req->r_inode) {
 908                 if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
 909                         inode = req->r_inode;
 910                         ihold(inode);
 911                 } else {
 912                         /* req->r_dentry is non-null for LSSNAP request */
 913                         rcu_read_lock();
 914                         inode = get_nonsnap_parent(req->r_dentry);
 915                         rcu_read_unlock();
 916                         dout("__choose_mds using snapdir's parent %p\n", inode);
 917                 }
 918         } else if (req->r_dentry) {
 919                 /* ignore race with rename; old or new d_parent is okay */
 920                 struct dentry *parent;
 921                 struct inode *dir;
 922
 923                 rcu_read_lock();
 924                 parent = READ_ONCE(req->r_dentry->d_parent);
 925                 dir = req->r_parent ? : d_inode_rcu(parent);
 926
 927                 if (!dir || dir->i_sb != mdsc->fsc->sb) {
 928                         /*  not this fs or parent went negative */
 929                         inode = d_inode(req->r_dentry);
 930                         if (inode)
 931                                 ihold(inode);
 932                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 933                         /* direct snapped/virtual snapdir requests
 934                          * based on parent dir inode */
 935                         inode = get_nonsnap_parent(parent);
 936                         dout("__choose_mds using nonsnap parent %p\n", inode);
 937                 } else {
 938                         /* dentry target */
 939                         inode = d_inode(req->r_dentry);
 940                         if (!inode || mode == USE_AUTH_MDS) {
 941                                 /* dir + name */
 942                                 inode = igrab(dir);
 943                                 hash = ceph_dentry_hash(dir, req->r_dentry);
 944                                 is_hash = true;
 945                         } else {
 946                                 ihold(inode);
 947                         }
 948                 }
 949                 rcu_read_unlock();
 950         }
 951
 952         dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 953              (int)hash, mode);
 954         if (!inode)
 955                 goto random;
 956         ci = ceph_inode(inode);
 957
 958         if (is_hash && S_ISDIR(inode->i_mode)) {
 959                 struct ceph_inode_frag frag;
 960                 int found;
 961
 962                 ceph_choose_frag(ci, hash, &frag, &found);
 963                 if (found) {
 964                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
 965                                 u8 r;
 966
 967                                 /* choose a random replica */
 968                                 get_random_bytes(&r, 1);
 969                                 r %= frag.ndist;
 970                                 mds = frag.dist[r];
 971                                 dout("choose_mds %p %llx.%llx "
 972                                      "frag %u mds%d (%d/%d)\n",
 973                                      inode, ceph_vinop(inode),
 974                                      frag.frag, mds,
 975                                      (int)r, frag.ndist);
 976                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 977                                     CEPH_MDS_STATE_ACTIVE &&
 978                                     !ceph_mdsmap_is_laggy(mdsc->mdsmap, mds))
 979                                         goto out;
 980                         }
 981
 982                         /* since this file/dir wasn't known to be
 983                          * replicated, then we want to look for the
 984                          * authoritative mds. */
 985                         if (frag.mds >= 0) {
 986                                 /* choose auth mds */
 987                                 mds = frag.mds;
 988                                 dout("choose_mds %p %llx.%llx "
 989                                      "frag %u mds%d (auth)\n",
 990                                      inode, ceph_vinop(inode), frag.frag, mds);
 991                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 992                                     CEPH_MDS_STATE_ACTIVE) {
 993                                         if (mode == USE_ANY_MDS &&
 994                                             !ceph_mdsmap_is_laggy(mdsc->mdsmap,
 995                                                                   mds))
 996                                                 goto out;
 997                                 }
 998                         }
 999                         mode = USE_AUTH_MDS;
1000                 }
1001         }
1002
1003         spin_lock(&ci->i_ceph_lock);
1004         cap = NULL;
1005         if (mode == USE_AUTH_MDS)
1006                 cap = ci->i_auth_cap;
1007         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
1008                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
1009         if (!cap) {
1010                 spin_unlock(&ci->i_ceph_lock);
1011                 ceph_async_iput(inode);
1012                 goto random;
1013         }
1014         mds = cap->session->s_mds;
1015         dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
1016              inode, ceph_vinop(inode), mds,
1017              cap == ci->i_auth_cap ? "auth " : "", cap);
1018         spin_unlock(&ci->i_ceph_lock);
1019 out:
1020         /* avoid calling iput_final() while holding mdsc->mutex or
1021          * in mds dispatch threads */
1022         ceph_async_iput(inode);
1023         return mds;
1024
1025 random:
1026         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
1027         dout("choose_mds chose random mds%d\n", mds);
1028         return mds;
1029 }
1030
1031
1032 /*
1033  * session messages
1034  */
1035 static struct ceph_msg *create_session_msg(u32 op, u64 seq)
1036 {
1037         struct ceph_msg *msg;
1038         struct ceph_mds_session_head *h;
1039
1040         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
1041                            false);
1042         if (!msg) {
1043                 pr_err("create_session_msg ENOMEM creating msg\n");
1044                 return NULL;
1045         }
1046         h = msg->front.iov_base;
1047         h->op = cpu_to_le32(op);
1048         h->seq = cpu_to_le64(seq);
1049
1050         return msg;
1051 }
1052
1053 static void encode_supported_features(void **p, void *end)
1054 {
1055         static const unsigned char bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
1056         static const size_t count = ARRAY_SIZE(bits);
1057
1058         if (count > 0) {
1059                 size_t i;
1060                 size_t size = ((size_t)bits[count - 1] + 64) / 64 * 8;
1061
1062                 BUG_ON(*p + 4 + size > end);
1063                 ceph_encode_32(p, size);
1064                 memset(*p, 0, size);
1065                 for (i = 0; i < count; i++)
1066                         ((unsigned char*)(*p))[i / 8] |= 1 << (bits[i] % 8);
1067                 *p += size;
1068         } else {
1069                 BUG_ON(*p + 4 > end);
1070                 ceph_encode_32(p, 0);
1071         }
1072 }
1073
1074 /*
1075  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
1076  * to include additional client metadata fields.
1077  */
1078 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
1079 {
1080         struct ceph_msg *msg;
1081         struct ceph_mds_session_head *h;
1082         int i = -1;
1083         int extra_bytes = 0;
1084         int metadata_key_count = 0;
1085         struct ceph_options *opt = mdsc->fsc->client->options;
1086         struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
1087         void *p, *end;
1088
1089         const char* metadata[][2] = {
1090                 {"hostname", mdsc->nodename},
1091                 {"kernel_version", init_utsname()->release},
1092                 {"entity_id", opt->name ? : ""},
1093                 {"root", fsopt->server_path ? : "/"},
1094                 {NULL, NULL}
1095         };
1096
1097         /* Calculate serialized length of metadata */
1098         extra_bytes = 4;  /* map length */
1099         for (i = 0; metadata[i][0]; ++i) {
1100                 extra_bytes += 8 + strlen(metadata[i][0]) +
1101                         strlen(metadata[i][1]);
1102                 metadata_key_count++;
1103         }
1104         /* supported feature */
1105         extra_bytes += 4 + 8;
1106
1107         /* Allocate the message */
1108         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + extra_bytes,
1109                            GFP_NOFS, false);
1110         if (!msg) {
1111                 pr_err("create_session_msg ENOMEM creating msg\n");
1112                 return NULL;
1113         }
1114         p = msg->front.iov_base;
1115         end = p + msg->front.iov_len;
1116
1117         h = p;
1118         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
1119         h->seq = cpu_to_le64(seq);
1120
1121         /*
1122          * Serialize client metadata into waiting buffer space, using
1123          * the format that userspace expects for map<string, string>
1124          *
1125          * ClientSession messages with metadata are v2
1126          */
1127         msg->hdr.version = cpu_to_le16(3);
1128         msg->hdr.compat_version = cpu_to_le16(1);
1129
1130         /* The write pointer, following the session_head structure */
1131         p += sizeof(*h);
1132
1133         /* Number of entries in the map */
1134         ceph_encode_32(&p, metadata_key_count);
1135
1136         /* Two length-prefixed strings for each entry in the map */
1137         for (i = 0; metadata[i][0]; ++i) {
1138                 size_t const key_len = strlen(metadata[i][0]);
1139                 size_t const val_len = strlen(metadata[i][1]);
1140
1141                 ceph_encode_32(&p, key_len);
1142                 memcpy(p, metadata[i][0], key_len);
1143                 p += key_len;
1144                 ceph_encode_32(&p, val_len);
1145                 memcpy(p, metadata[i][1], val_len);
1146                 p += val_len;
1147         }
1148
1149         encode_supported_features(&p, end);
1150         msg->front.iov_len = p - msg->front.iov_base;
1151         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1152
1153         return msg;
1154 }
1155
1156 /*
1157  * send session open request.
1158  *
1159  * called under mdsc->mutex
1160  */
1161 static int __open_session(struct ceph_mds_client *mdsc,
1162                           struct ceph_mds_session *session)
1163 {
1164         struct ceph_msg *msg;
1165         int mstate;
1166         int mds = session->s_mds;
1167
1168         /* wait for mds to go active? */
1169         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
1170         dout("open_session to mds%d (%s)\n", mds,
1171              ceph_mds_state_name(mstate));
1172         session->s_state = CEPH_MDS_SESSION_OPENING;
1173         session->s_renew_requested = jiffies;
1174
1175         /* send connect message */
1176         msg = create_session_open_msg(mdsc, session->s_seq);
1177         if (!msg)
1178                 return -ENOMEM;
1179         ceph_con_send(&session->s_con, msg);
1180         return 0;
1181 }
1182
1183 /*
1184  * open sessions for any export targets for the given mds
1185  *
1186  * called under mdsc->mutex
1187  */
1188 static struct ceph_mds_session *
1189 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
1190 {
1191         struct ceph_mds_session *session;
1192
1193         session = __ceph_lookup_mds_session(mdsc, target);
1194         if (!session) {
1195                 session = register_session(mdsc, target);
1196                 if (IS_ERR(session))
1197                         return session;
1198         }
1199         if (session->s_state == CEPH_MDS_SESSION_NEW ||
1200             session->s_state == CEPH_MDS_SESSION_CLOSING)
1201                 __open_session(mdsc, session);
1202
1203         return session;
1204 }
1205
1206 struct ceph_mds_session *
1207 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
1208 {
1209         struct ceph_mds_session *session;
1210
1211         dout("open_export_target_session to mds%d\n", target);
1212
1213         mutex_lock(&mdsc->mutex);
1214         session = __open_export_target_session(mdsc, target);
1215         mutex_unlock(&mdsc->mutex);
1216
1217         return session;
1218 }
1219
1220 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
1221                                           struct ceph_mds_session *session)
1222 {
1223         struct ceph_mds_info *mi;
1224         struct ceph_mds_session *ts;
1225         int i, mds = session->s_mds;
1226
1227         if (mds >= mdsc->mdsmap->m_num_mds)
1228                 return;
1229
1230         mi = &mdsc->mdsmap->m_info[mds];
1231         dout("open_export_target_sessions for mds%d (%d targets)\n",
1232              session->s_mds, mi->num_export_targets);
1233
1234         for (i = 0; i < mi->num_export_targets; i++) {
1235                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1236                 if (!IS_ERR(ts))
1237                         ceph_put_mds_session(ts);
1238         }
1239 }
1240
1241 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1242                                            struct ceph_mds_session *session)
1243 {
1244         mutex_lock(&mdsc->mutex);
1245         __open_export_target_sessions(mdsc, session);
1246         mutex_unlock(&mdsc->mutex);
1247 }
1248
1249 /*
1250  * session caps
1251  */
1252
1253 static void detach_cap_releases(struct ceph_mds_session *session,
1254                                 struct list_head *target)
1255 {
1256         lockdep_assert_held(&session->s_cap_lock);
1257
1258         list_splice_init(&session->s_cap_releases, target);
1259         session->s_num_cap_releases = 0;
1260         dout("dispose_cap_releases mds%d\n", session->s_mds);
1261 }
1262
1263 static void dispose_cap_releases(struct ceph_mds_client *mdsc,
1264                                  struct list_head *dispose)
1265 {
1266         while (!list_empty(dispose)) {
1267                 struct ceph_cap *cap;
1268                 /* zero out the in-progress message */
1269                 cap = list_first_entry(dispose, struct ceph_cap, session_caps);
1270                 list_del(&cap->session_caps);
1271                 ceph_put_cap(mdsc, cap);
1272         }
1273 }
1274
1275 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1276                                      struct ceph_mds_session *session)
1277 {
1278         struct ceph_mds_request *req;
1279         struct rb_node *p;
1280         struct ceph_inode_info *ci;
1281
1282         dout("cleanup_session_requests mds%d\n", session->s_mds);
1283         mutex_lock(&mdsc->mutex);
1284         while (!list_empty(&session->s_unsafe)) {
1285                 req = list_first_entry(&session->s_unsafe,
1286                                        struct ceph_mds_request, r_unsafe_item);
1287                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1288                                     req->r_tid);
1289                 if (req->r_target_inode) {
1290                         /* dropping unsafe change of inode's attributes */
1291                         ci = ceph_inode(req->r_target_inode);
1292                         errseq_set(&ci->i_meta_err, -EIO);
1293                 }
1294                 if (req->r_unsafe_dir) {
1295                         /* dropping unsafe directory operation */
1296                         ci = ceph_inode(req->r_unsafe_dir);
1297                         errseq_set(&ci->i_meta_err, -EIO);
1298                 }
1299                 __unregister_request(mdsc, req);
1300         }
1301         /* zero r_attempts, so kick_requests() will re-send requests */
1302         p = rb_first(&mdsc->request_tree);
1303         while (p) {
1304                 req = rb_entry(p, struct ceph_mds_request, r_node);
1305                 p = rb_next(p);
1306                 if (req->r_session &&
1307                     req->r_session->s_mds == session->s_mds)
1308                         req->r_attempts = 0;
1309         }
1310         mutex_unlock(&mdsc->mutex);
1311 }
1312
1313 /*
1314  * Helper to safely iterate over all caps associated with a session, with
1315  * special care taken to handle a racing __ceph_remove_cap().
1316  *
1317  * Caller must hold session s_mutex.
1318  */
1319 int ceph_iterate_session_caps(struct ceph_mds_session *session,
1320                               int (*cb)(struct inode *, struct ceph_cap *,
1321                                         void *), void *arg)
1322 {
1323         struct list_head *p;
1324         struct ceph_cap *cap;
1325         struct inode *inode, *last_inode = NULL;
1326         struct ceph_cap *old_cap = NULL;
1327         int ret;
1328
1329         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1330         spin_lock(&session->s_cap_lock);
1331         p = session->s_caps.next;
1332         while (p != &session->s_caps) {
1333                 cap = list_entry(p, struct ceph_cap, session_caps);
1334                 inode = igrab(&cap->ci->vfs_inode);
1335                 if (!inode) {
1336                         p = p->next;
1337                         continue;
1338                 }
1339                 session->s_cap_iterator = cap;
1340                 spin_unlock(&session->s_cap_lock);
1341
1342                 if (last_inode) {
1343                         /* avoid calling iput_final() while holding
1344                          * s_mutex or in mds dispatch threads */
1345                         ceph_async_iput(last_inode);
1346                         last_inode = NULL;
1347                 }
1348                 if (old_cap) {
1349                         ceph_put_cap(session->s_mdsc, old_cap);
1350                         old_cap = NULL;
1351                 }
1352
1353                 ret = cb(inode, cap, arg);
1354                 last_inode = inode;
1355
1356                 spin_lock(&session->s_cap_lock);
1357                 p = p->next;
1358                 if (!cap->ci) {
1359                         dout("iterate_session_caps  finishing cap %p removal\n",
1360                              cap);
1361                         BUG_ON(cap->session != session);
1362                         cap->session = NULL;
1363                         list_del_init(&cap->session_caps);
1364                         session->s_nr_caps--;
1365                         if (cap->queue_release)
1366                                 __ceph_queue_cap_release(session, cap);
1367                         else
1368                                 old_cap = cap;  /* put_cap it w/o locks held */
1369                 }
1370                 if (ret < 0)
1371                         goto out;
1372         }
1373         ret = 0;
1374 out:
1375         session->s_cap_iterator = NULL;
1376         spin_unlock(&session->s_cap_lock);
1377
1378         ceph_async_iput(last_inode);
1379         if (old_cap)
1380                 ceph_put_cap(session->s_mdsc, old_cap);
1381
1382         return ret;
1383 }
1384
1385 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1386                                   void *arg)
1387 {
1388         struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1389         struct ceph_inode_info *ci = ceph_inode(inode);
1390         LIST_HEAD(to_remove);
1391         bool dirty_dropped = false;
1392         bool invalidate = false;
1393
1394         dout("removing cap %p, ci is %p, inode is %p\n",
1395              cap, ci, &ci->vfs_inode);
1396         spin_lock(&ci->i_ceph_lock);
1397         if (cap->mds_wanted | cap->issued)
1398                 ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1399         __ceph_remove_cap(cap, false);
1400         if (!ci->i_auth_cap) {
1401                 struct ceph_cap_flush *cf;
1402                 struct ceph_mds_client *mdsc = fsc->mdsc;
1403
1404                 if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
1405                         if (inode->i_data.nrpages > 0)
1406                                 invalidate = true;
1407                         if (ci->i_wrbuffer_ref > 0)
1408                                 mapping_set_error(&inode->i_data, -EIO);
1409                 }
1410
1411                 while (!list_empty(&ci->i_cap_flush_list)) {
1412                         cf = list_first_entry(&ci->i_cap_flush_list,
1413                                               struct ceph_cap_flush, i_list);
1414                         list_move(&cf->i_list, &to_remove);
1415                 }
1416
1417                 spin_lock(&mdsc->cap_dirty_lock);
1418
1419                 list_for_each_entry(cf, &to_remove, i_list)
1420                         list_del(&cf->g_list);
1421
1422                 if (!list_empty(&ci->i_dirty_item)) {
1423                         pr_warn_ratelimited(
1424                                 " dropping dirty %s state for %p %lld\n",
1425                                 ceph_cap_string(ci->i_dirty_caps),
1426                                 inode, ceph_ino(inode));
1427                         ci->i_dirty_caps = 0;
1428                         list_del_init(&ci->i_dirty_item);
1429                         dirty_dropped = true;
1430                 }
1431                 if (!list_empty(&ci->i_flushing_item)) {
1432                         pr_warn_ratelimited(
1433                                 " dropping dirty+flushing %s state for %p %lld\n",
1434                                 ceph_cap_string(ci->i_flushing_caps),
1435                                 inode, ceph_ino(inode));
1436                         ci->i_flushing_caps = 0;
1437                         list_del_init(&ci->i_flushing_item);
1438                         mdsc->num_cap_flushing--;
1439                         dirty_dropped = true;
1440                 }
1441                 spin_unlock(&mdsc->cap_dirty_lock);
1442
1443                 if (dirty_dropped) {
1444                         errseq_set(&ci->i_meta_err, -EIO);
1445
1446                         if (ci->i_wrbuffer_ref_head == 0 &&
1447                             ci->i_wr_ref == 0 &&
1448                             ci->i_dirty_caps == 0 &&
1449                             ci->i_flushing_caps == 0) {
1450                                 ceph_put_snap_context(ci->i_head_snapc);
1451                                 ci->i_head_snapc = NULL;
1452                         }
1453                 }
1454
1455                 if (atomic_read(&ci->i_filelock_ref) > 0) {
1456                         /* make further file lock syscall return -EIO */
1457                         ci->i_ceph_flags |= CEPH_I_ERROR_FILELOCK;
1458                         pr_warn_ratelimited(" dropping file locks for %p %lld\n",
1459                                             inode, ceph_ino(inode));
1460                 }
1461
1462                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1463                         list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
1464                         ci->i_prealloc_cap_flush = NULL;
1465                 }
1466         }
1467         spin_unlock(&ci->i_ceph_lock);
1468         while (!list_empty(&to_remove)) {
1469                 struct ceph_cap_flush *cf;
1470                 cf = list_first_entry(&to_remove,
1471                                       struct ceph_cap_flush, i_list);
1472                 list_del(&cf->i_list);
1473                 ceph_free_cap_flush(cf);
1474         }
1475
1476         wake_up_all(&ci->i_cap_wq);
1477         if (invalidate)
1478                 ceph_queue_invalidate(inode);
1479         if (dirty_dropped)
1480                 iput(inode);
1481         return 0;
1482 }
1483
1484 /*
1485  * caller must hold session s_mutex
1486  */
1487 static void remove_session_caps(struct ceph_mds_session *session)
1488 {
1489         struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1490         struct super_block *sb = fsc->sb;
1491         LIST_HEAD(dispose);
1492
1493         dout("remove_session_caps on %p\n", session);
1494         ceph_iterate_session_caps(session, remove_session_caps_cb, fsc);
1495
1496         wake_up_all(&fsc->mdsc->cap_flushing_wq);
1497
1498         spin_lock(&session->s_cap_lock);
1499         if (session->s_nr_caps > 0) {
1500                 struct inode *inode;
1501                 struct ceph_cap *cap, *prev = NULL;
1502                 struct ceph_vino vino;
1503                 /*
1504                  * iterate_session_caps() skips inodes that are being
1505                  * deleted, we need to wait until deletions are complete.
1506                  * __wait_on_freeing_inode() is designed for the job,
1507                  * but it is not exported, so use lookup inode function
1508                  * to access it.
1509                  */
1510                 while (!list_empty(&session->s_caps)) {
1511                         cap = list_entry(session->s_caps.next,
1512                                          struct ceph_cap, session_caps);
1513                         if (cap == prev)
1514                                 break;
1515                         prev = cap;
1516                         vino = cap->ci->i_vino;
1517                         spin_unlock(&session->s_cap_lock);
1518
1519                         inode = ceph_find_inode(sb, vino);
1520                          /* avoid calling iput_final() while holding s_mutex */
1521                         ceph_async_iput(inode);
1522
1523                         spin_lock(&session->s_cap_lock);
1524                 }
1525         }
1526
1527         // drop cap expires and unlock s_cap_lock
1528         detach_cap_releases(session, &dispose);
1529
1530         BUG_ON(session->s_nr_caps > 0);
1531         BUG_ON(!list_empty(&session->s_cap_flushing));
1532         spin_unlock(&session->s_cap_lock);
1533         dispose_cap_releases(session->s_mdsc, &dispose);
1534 }
1535
1536 enum {
1537         RECONNECT,
1538         RENEWCAPS,
1539         FORCE_RO,
1540 };
1541
1542 /*
1543  * wake up any threads waiting on this session's caps.  if the cap is
1544  * old (didn't get renewed on the client reconnect), remove it now.
1545  *
1546  * caller must hold s_mutex.
1547  */
1548 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1549                               void *arg)
1550 {
1551         struct ceph_inode_info *ci = ceph_inode(inode);
1552         unsigned long ev = (unsigned long)arg;
1553
1554         if (ev == RECONNECT) {
1555                 spin_lock(&ci->i_ceph_lock);
1556                 ci->i_wanted_max_size = 0;
1557                 ci->i_requested_max_size = 0;
1558                 spin_unlock(&ci->i_ceph_lock);
1559         } else if (ev == RENEWCAPS) {
1560                 if (cap->cap_gen < cap->session->s_cap_gen) {
1561                         /* mds did not re-issue stale cap */
1562                         spin_lock(&ci->i_ceph_lock);
1563                         cap->issued = cap->implemented = CEPH_CAP_PIN;
1564                         /* make sure mds knows what we want */
1565                         if (__ceph_caps_file_wanted(ci) & ~cap->mds_wanted)
1566                                 ci->i_ceph_flags |= CEPH_I_CAP_DROPPED;
1567                         spin_unlock(&ci->i_ceph_lock);
1568                 }
1569         } else if (ev == FORCE_RO) {
1570         }
1571         wake_up_all(&ci->i_cap_wq);
1572         return 0;
1573 }
1574
1575 static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
1576 {
1577         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1578         ceph_iterate_session_caps(session, wake_up_session_cb,
1579                                   (void *)(unsigned long)ev);
1580 }
1581
1582 /*
1583  * Send periodic message to MDS renewing all currently held caps.  The
1584  * ack will reset the expiration for all caps from this session.
1585  *
1586  * caller holds s_mutex
1587  */
1588 static int send_renew_caps(struct ceph_mds_client *mdsc,
1589                            struct ceph_mds_session *session)
1590 {
1591         struct ceph_msg *msg;
1592         int state;
1593
1594         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1595             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1596                 pr_info("mds%d caps stale\n", session->s_mds);
1597         session->s_renew_requested = jiffies;
1598
1599         /* do not try to renew caps until a recovering mds has reconnected
1600          * with its clients. */
1601         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1602         if (state < CEPH_MDS_STATE_RECONNECT) {
1603                 dout("send_renew_caps ignoring mds%d (%s)\n",
1604                      session->s_mds, ceph_mds_state_name(state));
1605                 return 0;
1606         }
1607
1608         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1609                 ceph_mds_state_name(state));
1610         msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1611                                  ++session->s_renew_seq);
1612         if (!msg)
1613                 return -ENOMEM;
1614         ceph_con_send(&session->s_con, msg);
1615         return 0;
1616 }
1617
1618 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1619                              struct ceph_mds_session *session, u64 seq)
1620 {
1621         struct ceph_msg *msg;
1622
1623         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1624              session->s_mds, ceph_session_state_name(session->s_state), seq);
1625         msg = create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1626         if (!msg)
1627                 return -ENOMEM;
1628         ceph_con_send(&session->s_con, msg);
1629         return 0;
1630 }
1631
1632
1633 /*
1634  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1635  *
1636  * Called under session->s_mutex
1637  */
1638 static void renewed_caps(struct ceph_mds_client *mdsc,
1639                          struct ceph_mds_session *session, int is_renew)
1640 {
1641         int was_stale;
1642         int wake = 0;
1643
1644         spin_lock(&session->s_cap_lock);
1645         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1646
1647         session->s_cap_ttl = session->s_renew_requested +
1648                 mdsc->mdsmap->m_session_timeout*HZ;
1649
1650         if (was_stale) {
1651                 if (time_before(jiffies, session->s_cap_ttl)) {
1652                         pr_info("mds%d caps renewed\n", session->s_mds);
1653                         wake = 1;
1654                 } else {
1655                         pr_info("mds%d caps still stale\n", session->s_mds);
1656                 }
1657         }
1658         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1659              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1660              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1661         spin_unlock(&session->s_cap_lock);
1662
1663         if (wake)
1664                 wake_up_session_caps(session, RENEWCAPS);
1665 }
1666
1667 /*
1668  * send a session close request
1669  */
1670 static int request_close_session(struct ceph_mds_client *mdsc,
1671                                  struct ceph_mds_session *session)
1672 {
1673         struct ceph_msg *msg;
1674
1675         dout("request_close_session mds%d state %s seq %lld\n",
1676              session->s_mds, ceph_session_state_name(session->s_state),
1677              session->s_seq);
1678         msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1679         if (!msg)
1680                 return -ENOMEM;
1681         ceph_con_send(&session->s_con, msg);
1682         return 1;
1683 }
1684
1685 /*
1686  * Called with s_mutex held.
1687  */
1688 static int __close_session(struct ceph_mds_client *mdsc,
1689                          struct ceph_mds_session *session)
1690 {
1691         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1692                 return 0;
1693         session->s_state = CEPH_MDS_SESSION_CLOSING;
1694         return request_close_session(mdsc, session);
1695 }
1696
1697 static bool drop_negative_children(struct dentry *dentry)
1698 {
1699         struct dentry *child;
1700         bool all_negative = true;
1701
1702         if (!d_is_dir(dentry))
1703                 goto out;
1704
1705         spin_lock(&dentry->d_lock);
1706         list_for_each_entry(child, &dentry->d_subdirs, d_child) {
1707                 if (d_really_is_positive(child)) {
1708                         all_negative = false;
1709                         break;
1710                 }
1711         }
1712         spin_unlock(&dentry->d_lock);
1713
1714         if (all_negative)
1715                 shrink_dcache_parent(dentry);
1716 out:
1717         return all_negative;
1718 }
1719
1720 /*
1721  * Trim old(er) caps.
1722  *
1723  * Because we can't cache an inode without one or more caps, we do
1724  * this indirectly: if a cap is unused, we prune its aliases, at which
1725  * point the inode will hopefully get dropped to.
1726  *
1727  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1728  * memory pressure from the MDS, though, so it needn't be perfect.
1729  */
1730 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1731 {
1732         int *remaining = arg;
1733         struct ceph_inode_info *ci = ceph_inode(inode);
1734         int used, wanted, oissued, mine;
1735
1736         if (*remaining <= 0)
1737                 return -1;
1738
1739         spin_lock(&ci->i_ceph_lock);
1740         mine = cap->issued | cap->implemented;
1741         used = __ceph_caps_used(ci);
1742         wanted = __ceph_caps_file_wanted(ci);
1743         oissued = __ceph_caps_issued_other(ci, cap);
1744
1745         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1746              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1747              ceph_cap_string(used), ceph_cap_string(wanted));
1748         if (cap == ci->i_auth_cap) {
1749                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1750                     !list_empty(&ci->i_cap_snaps))
1751                         goto out;
1752                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1753                         goto out;
1754                 /* Note: it's possible that i_filelock_ref becomes non-zero
1755                  * after dropping auth caps. It doesn't hurt because reply
1756                  * of lock mds request will re-add auth caps. */
1757                 if (atomic_read(&ci->i_filelock_ref) > 0)
1758                         goto out;
1759         }
1760         /* The inode has cached pages, but it's no longer used.
1761          * we can safely drop it */
1762         if (wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1763             !(oissued & CEPH_CAP_FILE_CACHE)) {
1764           used = 0;
1765           oissued = 0;
1766         }
1767         if ((used | wanted) & ~oissued & mine)
1768                 goto out;   /* we need these caps */
1769
1770         if (oissued) {
1771                 /* we aren't the only cap.. just remove us */
1772                 __ceph_remove_cap(cap, true);
1773                 (*remaining)--;
1774         } else {
1775                 struct dentry *dentry;
1776                 /* try dropping referring dentries */
1777                 spin_unlock(&ci->i_ceph_lock);
1778                 dentry = d_find_any_alias(inode);
1779                 if (dentry && drop_negative_children(dentry)) {
1780                         int count;
1781                         dput(dentry);
1782                         d_prune_aliases(inode);
1783                         count = atomic_read(&inode->i_count);
1784                         if (count == 1)
1785                                 (*remaining)--;
1786                         dout("trim_caps_cb %p cap %p pruned, count now %d\n",
1787                              inode, cap, count);
1788                 } else {
1789                         dput(dentry);
1790                 }
1791                 return 0;
1792         }
1793
1794 out:
1795         spin_unlock(&ci->i_ceph_lock);
1796         return 0;
1797 }
1798
1799 /*
1800  * Trim session cap count down to some max number.
1801  */
1802 int ceph_trim_caps(struct ceph_mds_client *mdsc,
1803                    struct ceph_mds_session *session,
1804                    int max_caps)
1805 {
1806         int trim_caps = session->s_nr_caps - max_caps;
1807
1808         dout("trim_caps mds%d start: %d / %d, trim %d\n",
1809              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1810         if (trim_caps > 0) {
1811                 int remaining = trim_caps;
1812
1813                 ceph_iterate_session_caps(session, trim_caps_cb, &remaining);
1814                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1815                      session->s_mds, session->s_nr_caps, max_caps,
1816                         trim_caps - remaining);
1817         }
1818
1819         ceph_flush_cap_releases(mdsc, session);
1820         return 0;
1821 }
1822
1823 static int check_caps_flush(struct ceph_mds_client *mdsc,
1824                             u64 want_flush_tid)
1825 {
1826         int ret = 1;
1827
1828         spin_lock(&mdsc->cap_dirty_lock);
1829         if (!list_empty(&mdsc->cap_flush_list)) {
1830                 struct ceph_cap_flush *cf =
1831                         list_first_entry(&mdsc->cap_flush_list,
1832                                          struct ceph_cap_flush, g_list);
1833                 if (cf->tid <= want_flush_tid) {
1834                         dout("check_caps_flush still flushing tid "
1835                              "%llu <= %llu\n", cf->tid, want_flush_tid);
1836                         ret = 0;
1837                 }
1838         }
1839         spin_unlock(&mdsc->cap_dirty_lock);
1840         return ret;
1841 }
1842
1843 /*
1844  * flush all dirty inode data to disk.
1845  *
1846  * returns true if we've flushed through want_flush_tid
1847  */
1848 static void wait_caps_flush(struct ceph_mds_client *mdsc,
1849                             u64 want_flush_tid)
1850 {
1851         dout("check_caps_flush want %llu\n", want_flush_tid);
1852
1853         wait_event(mdsc->cap_flushing_wq,
1854                    check_caps_flush(mdsc, want_flush_tid));
1855
1856         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
1857 }
1858
1859 /*
1860  * called under s_mutex
1861  */
1862 static void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1863                                    struct ceph_mds_session *session)
1864 {
1865         struct ceph_msg *msg = NULL;
1866         struct ceph_mds_cap_release *head;
1867         struct ceph_mds_cap_item *item;
1868         struct ceph_osd_client *osdc = &mdsc->fsc->client->osdc;
1869         struct ceph_cap *cap;
1870         LIST_HEAD(tmp_list);
1871         int num_cap_releases;
1872         __le32  barrier, *cap_barrier;
1873
1874         down_read(&osdc->lock);
1875         barrier = cpu_to_le32(osdc->epoch_barrier);
1876         up_read(&osdc->lock);
1877
1878         spin_lock(&session->s_cap_lock);
1879 again:
1880         list_splice_init(&session->s_cap_releases, &tmp_list);
1881         num_cap_releases = session->s_num_cap_releases;
1882         session->s_num_cap_releases = 0;
1883         spin_unlock(&session->s_cap_lock);
1884
1885         while (!list_empty(&tmp_list)) {
1886                 if (!msg) {
1887                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
1888                                         PAGE_SIZE, GFP_NOFS, false);
1889                         if (!msg)
1890                                 goto out_err;
1891                         head = msg->front.iov_base;
1892                         head->num = cpu_to_le32(0);
1893                         msg->front.iov_len = sizeof(*head);
1894
1895                         msg->hdr.version = cpu_to_le16(2);
1896                         msg->hdr.compat_version = cpu_to_le16(1);
1897                 }
1898
1899                 cap = list_first_entry(&tmp_list, struct ceph_cap,
1900                                         session_caps);
1901                 list_del(&cap->session_caps);
1902                 num_cap_releases--;
1903
1904                 head = msg->front.iov_base;
1905                 put_unaligned_le32(get_unaligned_le32(&head->num) + 1,
1906                                    &head->num);
1907                 item = msg->front.iov_base + msg->front.iov_len;
1908                 item->ino = cpu_to_le64(cap->cap_ino);
1909                 item->cap_id = cpu_to_le64(cap->cap_id);
1910                 item->migrate_seq = cpu_to_le32(cap->mseq);
1911                 item->seq = cpu_to_le32(cap->issue_seq);
1912                 msg->front.iov_len += sizeof(*item);
1913
1914                 ceph_put_cap(mdsc, cap);
1915
1916                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
1917                         // Append cap_barrier field
1918                         cap_barrier = msg->front.iov_base + msg->front.iov_len;
1919                         *cap_barrier = barrier;
1920                         msg->front.iov_len += sizeof(*cap_barrier);
1921
1922                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1923                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1924                         ceph_con_send(&session->s_con, msg);
1925                         msg = NULL;
1926                 }
1927         }
1928
1929         BUG_ON(num_cap_releases != 0);
1930
1931         spin_lock(&session->s_cap_lock);
1932         if (!list_empty(&session->s_cap_releases))
1933                 goto again;
1934         spin_unlock(&session->s_cap_lock);
1935
1936         if (msg) {
1937                 // Append cap_barrier field
1938                 cap_barrier = msg->front.iov_base + msg->front.iov_len;
1939                 *cap_barrier = barrier;
1940                 msg->front.iov_len += sizeof(*cap_barrier);
1941
1942                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1943                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1944                 ceph_con_send(&session->s_con, msg);
1945         }
1946         return;
1947 out_err:
1948         pr_err("send_cap_releases mds%d, failed to allocate message\n",
1949                 session->s_mds);
1950         spin_lock(&session->s_cap_lock);
1951         list_splice(&tmp_list, &session->s_cap_releases);
1952         session->s_num_cap_releases += num_cap_releases;
1953         spin_unlock(&session->s_cap_lock);
1954 }
1955
1956 static void ceph_cap_release_work(struct work_struct *work)
1957 {
1958         struct ceph_mds_session *session =
1959                 container_of(work, struct ceph_mds_session, s_cap_release_work);
1960
1961         mutex_lock(&session->s_mutex);
1962         if (session->s_state == CEPH_MDS_SESSION_OPEN ||
1963             session->s_state == CEPH_MDS_SESSION_HUNG)
1964                 ceph_send_cap_releases(session->s_mdsc, session);
1965         mutex_unlock(&session->s_mutex);
1966         ceph_put_mds_session(session);
1967 }
1968
1969 void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
1970                              struct ceph_mds_session *session)
1971 {
1972         if (mdsc->stopping)
1973                 return;
1974
1975         get_session(session);
1976         if (queue_work(mdsc->fsc->cap_wq,
1977                        &session->s_cap_release_work)) {
1978                 dout("cap release work queued\n");
1979         } else {
1980                 ceph_put_mds_session(session);
1981                 dout("failed to queue cap release work\n");
1982         }
1983 }
1984
1985 /*
1986  * caller holds session->s_cap_lock
1987  */
1988 void __ceph_queue_cap_release(struct ceph_mds_session *session,
1989                               struct ceph_cap *cap)
1990 {
1991         list_add_tail(&cap->session_caps, &session->s_cap_releases);
1992         session->s_num_cap_releases++;
1993
1994         if (!(session->s_num_cap_releases % CEPH_CAPS_PER_RELEASE))
1995                 ceph_flush_cap_releases(session->s_mdsc, session);
1996 }
1997
1998 static void ceph_cap_reclaim_work(struct work_struct *work)
1999 {
2000         struct ceph_mds_client *mdsc =
2001                 container_of(work, struct ceph_mds_client, cap_reclaim_work);
2002         int ret = ceph_trim_dentries(mdsc);
2003         if (ret == -EAGAIN)
2004                 ceph_queue_cap_reclaim_work(mdsc);
2005 }
2006
2007 void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc)
2008 {
2009         if (mdsc->stopping)
2010                 return;
2011
2012         if (queue_work(mdsc->fsc->cap_wq, &mdsc->cap_reclaim_work)) {
2013                 dout("caps reclaim work queued\n");
2014         } else {
2015                 dout("failed to queue caps release work\n");
2016         }
2017 }
2018
2019 void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr)
2020 {
2021         int val;
2022         if (!nr)
2023                 return;
2024         val = atomic_add_return(nr, &mdsc->cap_reclaim_pending);
2025         if ((val % CEPH_CAPS_PER_RELEASE) < nr) {
2026                 atomic_set(&mdsc->cap_reclaim_pending, 0);
2027                 ceph_queue_cap_reclaim_work(mdsc);
2028         }
2029 }
2030
2031 /*
2032  * requests
2033  */
2034
2035 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
2036                                     struct inode *dir)
2037 {
2038         struct ceph_inode_info *ci = ceph_inode(dir);
2039         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
2040         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
2041         size_t size = sizeof(struct ceph_mds_reply_dir_entry);
2042         unsigned int num_entries;
2043         int order;
2044
2045         spin_lock(&ci->i_ceph_lock);
2046         num_entries = ci->i_files + ci->i_subdirs;
2047         spin_unlock(&ci->i_ceph_lock);
2048         num_entries = max(num_entries, 1U);
2049         num_entries = min(num_entries, opt->max_readdir);
2050
2051         order = get_order(size * num_entries);
2052         while (order >= 0) {
2053                 rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
2054                                                              __GFP_NOWARN,
2055                                                              order);
2056                 if (rinfo->dir_entries)
2057                         break;
2058                 order--;
2059         }
2060         if (!rinfo->dir_entries)
2061                 return -ENOMEM;
2062
2063         num_entries = (PAGE_SIZE << order) / size;
2064         num_entries = min(num_entries, opt->max_readdir);
2065
2066         rinfo->dir_buf_size = PAGE_SIZE << order;
2067         req->r_num_caps = num_entries + 1;
2068         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
2069         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
2070         return 0;
2071 }
2072
2073 /*
2074  * Create an mds request.
2075  */
2076 struct ceph_mds_request *
2077 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
2078 {
2079         struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
2080         struct timespec64 ts;
2081
2082         if (!req)
2083                 return ERR_PTR(-ENOMEM);
2084
2085         mutex_init(&req->r_fill_mutex);
2086         req->r_mdsc = mdsc;
2087         req->r_started = jiffies;
2088         req->r_resend_mds = -1;
2089         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
2090         INIT_LIST_HEAD(&req->r_unsafe_target_item);
2091         req->r_fmode = -1;
2092         kref_init(&req->r_kref);
2093         RB_CLEAR_NODE(&req->r_node);
2094         INIT_LIST_HEAD(&req->r_wait);
2095         init_completion(&req->r_completion);
2096         init_completion(&req->r_safe_completion);
2097         INIT_LIST_HEAD(&req->r_unsafe_item);
2098
2099         ktime_get_coarse_real_ts64(&ts);
2100         req->r_stamp = timespec64_trunc(ts, mdsc->fsc->sb->s_time_gran);
2101
2102         req->r_op = op;
2103         req->r_direct_mode = mode;
2104         return req;
2105 }
2106
2107 /*
2108  * return oldest (lowest) request, tid in request tree, 0 if none.
2109  *
2110  * called under mdsc->mutex.
2111  */
2112 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
2113 {
2114         if (RB_EMPTY_ROOT(&mdsc->request_tree))
2115                 return NULL;
2116         return rb_entry(rb_first(&mdsc->request_tree),
2117                         struct ceph_mds_request, r_node);
2118 }
2119
2120 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
2121 {
2122         return mdsc->oldest_tid;
2123 }
2124
2125 /*
2126  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
2127  * on build_path_from_dentry in fs/cifs/dir.c.
2128  *
2129  * If @stop_on_nosnap, generate path relative to the first non-snapped
2130  * inode.
2131  *
2132  * Encode hidden .snap dirs as a double /, i.e.
2133  *   foo/.snap/bar -> foo//bar
2134  */
2135 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
2136                            int stop_on_nosnap)
2137 {
2138         struct dentry *temp;
2139         char *path;
2140         int pos;
2141         unsigned seq;
2142         u64 base;
2143
2144         if (!dentry)
2145                 return ERR_PTR(-EINVAL);
2146
2147         path = __getname();
2148         if (!path)
2149                 return ERR_PTR(-ENOMEM);
2150 retry:
2151         pos = PATH_MAX - 1;
2152         path[pos] = '\0';
2153
2154         seq = read_seqbegin(&rename_lock);
2155         rcu_read_lock();
2156         temp = dentry;
2157         for (;;) {
2158                 struct inode *inode;
2159
2160                 spin_lock(&temp->d_lock);
2161                 inode = d_inode(temp);
2162                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
2163                         dout("build_path path+%d: %p SNAPDIR\n",
2164                              pos, temp);
2165                 } else if (stop_on_nosnap && inode && dentry != temp &&
2166                            ceph_snap(inode) == CEPH_NOSNAP) {
2167                         spin_unlock(&temp->d_lock);
2168                         pos++; /* get rid of any prepended '/' */
2169                         break;
2170                 } else {
2171                         pos -= temp->d_name.len;
2172                         if (pos < 0) {
2173                                 spin_unlock(&temp->d_lock);
2174                                 break;
2175                         }
2176                         memcpy(path + pos, temp->d_name.name, temp->d_name.len);
2177                 }
2178                 spin_unlock(&temp->d_lock);
2179                 temp = READ_ONCE(temp->d_parent);
2180
2181                 /* Are we at the root? */
2182                 if (IS_ROOT(temp))
2183                         break;
2184
2185                 /* Are we out of buffer? */
2186                 if (--pos < 0)
2187                         break;
2188
2189                 path[pos] = '/';
2190         }
2191         base = ceph_ino(d_inode(temp));
2192         rcu_read_unlock();
2193
2194         if (read_seqretry(&rename_lock, seq))
2195                 goto retry;
2196
2197         if (pos < 0) {
2198                 /*
2199                  * A rename didn't occur, but somehow we didn't end up where
2200                  * we thought we would. Throw a warning and try again.
2201                  */
2202                 pr_warn("build_path did not end path lookup where "
2203                         "expected, pos is %d\n", pos);
2204                 goto retry;
2205         }
2206
2207         *pbase = base;
2208         *plen = PATH_MAX - 1 - pos;
2209         dout("build_path on %p %d built %llx '%.*s'\n",
2210              dentry, d_count(dentry), base, *plen, path + pos);
2211         return path + pos;
2212 }
2213
2214 static int build_dentry_path(struct dentry *dentry, struct inode *dir,
2215                              const char **ppath, int *ppathlen, u64 *pino,
2216                              bool *pfreepath, bool parent_locked)
2217 {
2218         char *path;
2219
2220         rcu_read_lock();
2221         if (!dir)
2222                 dir = d_inode_rcu(dentry->d_parent);
2223         if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) {
2224                 *pino = ceph_ino(dir);
2225                 rcu_read_unlock();
2226                 *ppath = dentry->d_name.name;
2227                 *ppathlen = dentry->d_name.len;
2228                 return 0;
2229         }
2230         rcu_read_unlock();
2231         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2232         if (IS_ERR(path))
2233                 return PTR_ERR(path);
2234         *ppath = path;
2235         *pfreepath = true;
2236         return 0;
2237 }
2238
2239 static int build_inode_path(struct inode *inode,
2240                             const char **ppath, int *ppathlen, u64 *pino,
2241                             bool *pfreepath)
2242 {
2243         struct dentry *dentry;
2244         char *path;
2245
2246         if (ceph_snap(inode) == CEPH_NOSNAP) {
2247                 *pino = ceph_ino(inode);
2248                 *ppathlen = 0;
2249                 return 0;
2250         }
2251         dentry = d_find_alias(inode);
2252         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2253         dput(dentry);
2254         if (IS_ERR(path))
2255                 return PTR_ERR(path);
2256         *ppath = path;
2257         *pfreepath = true;
2258         return 0;
2259 }
2260
2261 /*
2262  * request arguments may be specified via an inode *, a dentry *, or
2263  * an explicit ino+path.
2264  */
2265 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
2266                                   struct inode *rdiri, const char *rpath,
2267                                   u64 rino, const char **ppath, int *pathlen,
2268                                   u64 *ino, bool *freepath, bool parent_locked)
2269 {
2270         int r = 0;
2271
2272         if (rinode) {
2273                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
2274                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
2275                      ceph_snap(rinode));
2276         } else if (rdentry) {
2277                 r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
2278                                         freepath, parent_locked);
2279                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
2280                      *ppath);
2281         } else if (rpath || rino) {
2282                 *ino = rino;
2283                 *ppath = rpath;
2284                 *pathlen = rpath ? strlen(rpath) : 0;
2285                 dout(" path %.*s\n", *pathlen, rpath);
2286         }
2287
2288         return r;
2289 }
2290
2291 /*
2292  * called under mdsc->mutex
2293  */
2294 static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
2295                                                struct ceph_mds_request *req,
2296                                                int mds, bool drop_cap_releases)
2297 {
2298         struct ceph_msg *msg;
2299         struct ceph_mds_request_head *head;
2300         const char *path1 = NULL;
2301         const char *path2 = NULL;
2302         u64 ino1 = 0, ino2 = 0;
2303         int pathlen1 = 0, pathlen2 = 0;
2304         bool freepath1 = false, freepath2 = false;
2305         int len;
2306         u16 releases;
2307         void *p, *end;
2308         int ret;
2309
2310         ret = set_request_path_attr(req->r_inode, req->r_dentry,
2311                               req->r_parent, req->r_path1, req->r_ino1.ino,
2312                               &path1, &pathlen1, &ino1, &freepath1,
2313                               test_bit(CEPH_MDS_R_PARENT_LOCKED,
2314                                         &req->r_req_flags));
2315         if (ret < 0) {
2316                 msg = ERR_PTR(ret);
2317                 goto out;
2318         }
2319
2320         /* If r_old_dentry is set, then assume that its parent is locked */
2321         ret = set_request_path_attr(NULL, req->r_old_dentry,
2322                               req->r_old_dentry_dir,
2323                               req->r_path2, req->r_ino2.ino,
2324                               &path2, &pathlen2, &ino2, &freepath2, true);
2325         if (ret < 0) {
2326                 msg = ERR_PTR(ret);
2327                 goto out_free1;
2328         }
2329
2330         len = sizeof(*head) +
2331                 pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
2332                 sizeof(struct ceph_timespec);
2333
2334         /* calculate (max) length for cap releases */
2335         len += sizeof(struct ceph_mds_request_release) *
2336                 (!!req->r_inode_drop + !!req->r_dentry_drop +
2337                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
2338         if (req->r_dentry_drop)
2339                 len += pathlen1;
2340         if (req->r_old_dentry_drop)
2341                 len += pathlen2;
2342
2343         msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
2344         if (!msg) {
2345                 msg = ERR_PTR(-ENOMEM);
2346                 goto out_free2;
2347         }
2348
2349         msg->hdr.version = cpu_to_le16(2);
2350         msg->hdr.tid = cpu_to_le64(req->r_tid);
2351
2352         head = msg->front.iov_base;
2353         p = msg->front.iov_base + sizeof(*head);
2354         end = msg->front.iov_base + msg->front.iov_len;
2355
2356         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
2357         head->op = cpu_to_le32(req->r_op);
2358         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
2359         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
2360         head->ino = 0;
2361         head->args = req->r_args;
2362
2363         ceph_encode_filepath(&p, end, ino1, path1);
2364         ceph_encode_filepath(&p, end, ino2, path2);
2365
2366         /* make note of release offset, in case we need to replay */
2367         req->r_request_release_offset = p - msg->front.iov_base;
2368
2369         /* cap releases */
2370         releases = 0;
2371         if (req->r_inode_drop)
2372                 releases += ceph_encode_inode_release(&p,
2373                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
2374                       mds, req->r_inode_drop, req->r_inode_unless, 0);
2375         if (req->r_dentry_drop)
2376                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
2377                                 req->r_parent, mds, req->r_dentry_drop,
2378                                 req->r_dentry_unless);
2379         if (req->r_old_dentry_drop)
2380                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2381                                 req->r_old_dentry_dir, mds,
2382                                 req->r_old_dentry_drop,
2383                                 req->r_old_dentry_unless);
2384         if (req->r_old_inode_drop)
2385                 releases += ceph_encode_inode_release(&p,
2386                       d_inode(req->r_old_dentry),
2387                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2388
2389         if (drop_cap_releases) {
2390                 releases = 0;
2391                 p = msg->front.iov_base + req->r_request_release_offset;
2392         }
2393
2394         head->num_releases = cpu_to_le16(releases);
2395
2396         /* time stamp */
2397         {
2398                 struct ceph_timespec ts;
2399                 ceph_encode_timespec64(&ts, &req->r_stamp);
2400                 ceph_encode_copy(&p, &ts, sizeof(ts));
2401         }
2402
2403         BUG_ON(p > end);
2404         msg->front.iov_len = p - msg->front.iov_base;
2405         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2406
2407         if (req->r_pagelist) {
2408                 struct ceph_pagelist *pagelist = req->r_pagelist;
2409                 ceph_msg_data_add_pagelist(msg, pagelist);
2410                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2411         } else {
2412                 msg->hdr.data_len = 0;
2413         }
2414
2415         msg->hdr.data_off = cpu_to_le16(0);
2416
2417 out_free2:
2418         if (freepath2)
2419                 ceph_mdsc_free_path((char *)path2, pathlen2);
2420 out_free1:
2421         if (freepath1)
2422                 ceph_mdsc_free_path((char *)path1, pathlen1);
2423 out:
2424         return msg;
2425 }
2426
2427 /*
2428  * called under mdsc->mutex if error, under no mutex if
2429  * success.
2430  */
2431 static void complete_request(struct ceph_mds_client *mdsc,
2432                              struct ceph_mds_request *req)
2433 {
2434         if (req->r_callback)
2435                 req->r_callback(mdsc, req);
2436         complete_all(&req->r_completion);
2437 }
2438
2439 /*
2440  * called under mdsc->mutex
2441  */
2442 static int __prepare_send_request(struct ceph_mds_client *mdsc,
2443                                   struct ceph_mds_request *req,
2444                                   int mds, bool drop_cap_releases)
2445 {
2446         struct ceph_mds_request_head *rhead;
2447         struct ceph_msg *msg;
2448         int flags = 0;
2449
2450         req->r_attempts++;
2451         if (req->r_inode) {
2452                 struct ceph_cap *cap =
2453                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2454
2455                 if (cap)
2456                         req->r_sent_on_mseq = cap->mseq;
2457                 else
2458                         req->r_sent_on_mseq = -1;
2459         }
2460         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2461              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2462
2463         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2464                 void *p;
2465                 /*
2466                  * Replay.  Do not regenerate message (and rebuild
2467                  * paths, etc.); just use the original message.
2468                  * Rebuilding paths will break for renames because
2469                  * d_move mangles the src name.
2470                  */
2471                 msg = req->r_request;
2472                 rhead = msg->front.iov_base;
2473
2474                 flags = le32_to_cpu(rhead->flags);
2475                 flags |= CEPH_MDS_FLAG_REPLAY;
2476                 rhead->flags = cpu_to_le32(flags);
2477
2478                 if (req->r_target_inode)
2479                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2480
2481                 rhead->num_retry = req->r_attempts - 1;
2482
2483                 /* remove cap/dentry releases from message */
2484                 rhead->num_releases = 0;
2485
2486                 /* time stamp */
2487                 p = msg->front.iov_base + req->r_request_release_offset;
2488                 {
2489                         struct ceph_timespec ts;
2490                         ceph_encode_timespec64(&ts, &req->r_stamp);
2491                         ceph_encode_copy(&p, &ts, sizeof(ts));
2492                 }
2493
2494                 msg->front.iov_len = p - msg->front.iov_base;
2495                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2496                 return 0;
2497         }
2498
2499         if (req->r_request) {
2500                 ceph_msg_put(req->r_request);
2501                 req->r_request = NULL;
2502         }
2503         msg = create_request_message(mdsc, req, mds, drop_cap_releases);
2504         if (IS_ERR(msg)) {
2505                 req->r_err = PTR_ERR(msg);
2506                 return PTR_ERR(msg);
2507         }
2508         req->r_request = msg;
2509
2510         rhead = msg->front.iov_base;
2511         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2512         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2513                 flags |= CEPH_MDS_FLAG_REPLAY;
2514         if (req->r_parent)
2515                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2516         rhead->flags = cpu_to_le32(flags);
2517         rhead->num_fwd = req->r_num_fwd;
2518         rhead->num_retry = req->r_attempts - 1;
2519         rhead->ino = 0;
2520
2521         dout(" r_parent = %p\n", req->r_parent);
2522         return 0;
2523 }
2524
2525 /*
2526  * send request, or put it on the appropriate wait list.
2527  */
2528 static void __do_request(struct ceph_mds_client *mdsc,
2529                         struct ceph_mds_request *req)
2530 {
2531         struct ceph_mds_session *session = NULL;
2532         int mds = -1;
2533         int err = 0;
2534
2535         if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2536                 if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2537                         __unregister_request(mdsc, req);
2538                 return;
2539         }
2540
2541         if (req->r_timeout &&
2542             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2543                 dout("do_request timed out\n");
2544                 err = -EIO;
2545                 goto finish;
2546         }
2547         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2548                 dout("do_request forced umount\n");
2549                 err = -EIO;
2550                 goto finish;
2551         }
2552         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2553                 if (mdsc->mdsmap_err) {
2554                         err = mdsc->mdsmap_err;
2555                         dout("do_request mdsmap err %d\n", err);
2556                         goto finish;
2557                 }
2558                 if (mdsc->mdsmap->m_epoch == 0) {
2559                         dout("do_request no mdsmap, waiting for map\n");
2560                         list_add(&req->r_wait, &mdsc->waiting_for_map);
2561                         return;
2562                 }
2563                 if (!(mdsc->fsc->mount_options->flags &
2564                       CEPH_MOUNT_OPT_MOUNTWAIT) &&
2565                     !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2566                         err = -ENOENT;
2567                         pr_info("probably no mds server is up\n");
2568                         goto finish;
2569                 }
2570         }
2571
2572         put_request_session(req);
2573
2574         mds = __choose_mds(mdsc, req);
2575         if (mds < 0 ||
2576             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2577                 dout("do_request no mds or not active, waiting for map\n");
2578                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2579                 return;
2580         }
2581
2582         /* get, open session */
2583         session = __ceph_lookup_mds_session(mdsc, mds);
2584         if (!session) {
2585                 session = register_session(mdsc, mds);
2586                 if (IS_ERR(session)) {
2587                         err = PTR_ERR(session);
2588                         goto finish;
2589                 }
2590         }
2591         req->r_session = get_session(session);
2592
2593         dout("do_request mds%d session %p state %s\n", mds, session,
2594              ceph_session_state_name(session->s_state));
2595         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2596             session->s_state != CEPH_MDS_SESSION_HUNG) {
2597                 if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2598                         err = -EACCES;
2599                         goto out_session;
2600                 }
2601                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2602                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2603                         __open_session(mdsc, session);
2604                 list_add(&req->r_wait, &session->s_waiting);
2605                 goto out_session;
2606         }
2607
2608         /* send request */
2609         req->r_resend_mds = -1;   /* forget any previous mds hint */
2610
2611         if (req->r_request_started == 0)   /* note request start time */
2612                 req->r_request_started = jiffies;
2613
2614         err = __prepare_send_request(mdsc, req, mds, false);
2615         if (!err) {
2616                 ceph_msg_get(req->r_request);
2617                 ceph_con_send(&session->s_con, req->r_request);
2618         }
2619
2620 out_session:
2621         ceph_put_mds_session(session);
2622 finish:
2623         if (err) {
2624                 dout("__do_request early error %d\n", err);
2625                 req->r_err = err;
2626                 complete_request(mdsc, req);
2627                 __unregister_request(mdsc, req);
2628         }
2629         return;
2630 }
2631
2632 /*
2633  * called under mdsc->mutex
2634  */
2635 static void __wake_requests(struct ceph_mds_client *mdsc,
2636                             struct list_head *head)
2637 {
2638         struct ceph_mds_request *req;
2639         LIST_HEAD(tmp_list);
2640
2641         list_splice_init(head, &tmp_list);
2642
2643         while (!list_empty(&tmp_list)) {
2644                 req = list_entry(tmp_list.next,
2645                                  struct ceph_mds_request, r_wait);
2646                 list_del_init(&req->r_wait);
2647                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2648                 __do_request(mdsc, req);
2649         }
2650 }
2651
2652 /*
2653  * Wake up threads with requests pending for @mds, so that they can
2654  * resubmit their requests to a possibly different mds.
2655  */
2656 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2657 {
2658         struct ceph_mds_request *req;
2659         struct rb_node *p = rb_first(&mdsc->request_tree);
2660
2661         dout("kick_requests mds%d\n", mds);
2662         while (p) {
2663                 req = rb_entry(p, struct ceph_mds_request, r_node);
2664                 p = rb_next(p);
2665                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2666                         continue;
2667                 if (req->r_attempts > 0)
2668                         continue; /* only new requests */
2669                 if (req->r_session &&
2670                     req->r_session->s_mds == mds) {
2671                         dout(" kicking tid %llu\n", req->r_tid);
2672                         list_del_init(&req->r_wait);
2673                         __do_request(mdsc, req);
2674                 }
2675         }
2676 }
2677
2678 int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
2679                               struct ceph_mds_request *req)
2680 {
2681         int err;
2682
2683         /* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
2684         if (req->r_inode)
2685                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2686         if (req->r_parent) {
2687                 ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
2688                 ihold(req->r_parent);
2689         }
2690         if (req->r_old_dentry_dir)
2691                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2692                                   CEPH_CAP_PIN);
2693
2694         dout("submit_request on %p for inode %p\n", req, dir);
2695         mutex_lock(&mdsc->mutex);
2696         __register_request(mdsc, req, dir);
2697         __do_request(mdsc, req);
2698         err = req->r_err;
2699         mutex_unlock(&mdsc->mutex);
2700         return err;
2701 }
2702
2703 static int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
2704                                   struct ceph_mds_request *req)
2705 {
2706         int err;
2707
2708         /* wait */
2709         dout("do_request waiting\n");
2710         if (!req->r_timeout && req->r_wait_for_completion) {
2711                 err = req->r_wait_for_completion(mdsc, req);
2712         } else {
2713                 long timeleft = wait_for_completion_killable_timeout(
2714                                         &req->r_completion,
2715                                         ceph_timeout_jiffies(req->r_timeout));
2716                 if (timeleft > 0)
2717                         err = 0;
2718                 else if (!timeleft)
2719                         err = -EIO;  /* timed out */
2720                 else
2721                         err = timeleft;  /* killed */
2722         }
2723         dout("do_request waited, got %d\n", err);
2724         mutex_lock(&mdsc->mutex);
2725
2726         /* only abort if we didn't race with a real reply */
2727         if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2728                 err = le32_to_cpu(req->r_reply_info.head->result);
2729         } else if (err < 0) {
2730                 dout("aborted request %lld with %d\n", req->r_tid, err);
2731
2732                 /*
2733                  * ensure we aren't running concurrently with
2734                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2735                  * rely on locks (dir mutex) held by our caller.
2736                  */
2737                 mutex_lock(&req->r_fill_mutex);
2738                 req->r_err = err;
2739                 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
2740                 mutex_unlock(&req->r_fill_mutex);
2741
2742                 if (req->r_parent &&
2743                     (req->r_op & CEPH_MDS_OP_WRITE))
2744                         ceph_invalidate_dir_request(req);
2745         } else {
2746                 err = req->r_err;
2747         }
2748
2749         mutex_unlock(&mdsc->mutex);
2750         return err;
2751 }
2752
2753 /*
2754  * Synchrously perform an mds request.  Take care of all of the
2755  * session setup, forwarding, retry details.
2756  */
2757 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2758                          struct inode *dir,
2759                          struct ceph_mds_request *req)
2760 {
2761         int err;
2762
2763         dout("do_request on %p\n", req);
2764
2765         /* issue */
2766         err = ceph_mdsc_submit_request(mdsc, dir, req);
2767         if (!err)
2768                 err = ceph_mdsc_wait_request(mdsc, req);
2769         dout("do_request %p done, result %d\n", req, err);
2770         return err;
2771 }
2772
2773 /*
2774  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2775  * namespace request.
2776  */
2777 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2778 {
2779         struct inode *dir = req->r_parent;
2780         struct inode *old_dir = req->r_old_dentry_dir;
2781
2782         dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
2783
2784         ceph_dir_clear_complete(dir);
2785         if (old_dir)
2786                 ceph_dir_clear_complete(old_dir);
2787         if (req->r_dentry)
2788                 ceph_invalidate_dentry_lease(req->r_dentry);
2789         if (req->r_old_dentry)
2790                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2791 }
2792
2793 /*
2794  * Handle mds reply.
2795  *
2796  * We take the session mutex and parse and process the reply immediately.
2797  * This preserves the logical ordering of replies, capabilities, etc., sent
2798  * by the MDS as they are applied to our local cache.
2799  */
2800 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2801 {
2802         struct ceph_mds_client *mdsc = session->s_mdsc;
2803         struct ceph_mds_request *req;
2804         struct ceph_mds_reply_head *head = msg->front.iov_base;
2805         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2806         struct ceph_snap_realm *realm;
2807         u64 tid;
2808         int err, result;
2809         int mds = session->s_mds;
2810
2811         if (msg->front.iov_len < sizeof(*head)) {
2812                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2813                 ceph_msg_dump(msg);
2814                 return;
2815         }
2816
2817         /* get request, session */
2818         tid = le64_to_cpu(msg->hdr.tid);
2819         mutex_lock(&mdsc->mutex);
2820         req = lookup_get_request(mdsc, tid);
2821         if (!req) {
2822                 dout("handle_reply on unknown tid %llu\n", tid);
2823                 mutex_unlock(&mdsc->mutex);
2824                 return;
2825         }
2826         dout("handle_reply %p\n", req);
2827
2828         /* correct session? */
2829         if (req->r_session != session) {
2830                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2831                        " not mds%d\n", tid, session->s_mds,
2832                        req->r_session ? req->r_session->s_mds : -1);
2833                 mutex_unlock(&mdsc->mutex);
2834                 goto out;
2835         }
2836
2837         /* dup? */
2838         if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
2839             (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
2840                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2841                            head->safe ? "safe" : "unsafe", tid, mds);
2842                 mutex_unlock(&mdsc->mutex);
2843                 goto out;
2844         }
2845         if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
2846                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2847                            tid, mds);
2848                 mutex_unlock(&mdsc->mutex);
2849                 goto out;
2850         }
2851
2852         result = le32_to_cpu(head->result);
2853
2854         /*
2855          * Handle an ESTALE
2856          * if we're not talking to the authority, send to them
2857          * if the authority has changed while we weren't looking,
2858          * send to new authority
2859          * Otherwise we just have to return an ESTALE
2860          */
2861         if (result == -ESTALE) {
2862                 dout("got ESTALE on request %llu\n", req->r_tid);
2863                 req->r_resend_mds = -1;
2864                 if (req->r_direct_mode != USE_AUTH_MDS) {
2865                         dout("not using auth, setting for that now\n");
2866                         req->r_direct_mode = USE_AUTH_MDS;
2867                         __do_request(mdsc, req);
2868                         mutex_unlock(&mdsc->mutex);
2869                         goto out;
2870                 } else  {
2871                         int mds = __choose_mds(mdsc, req);
2872                         if (mds >= 0 && mds != req->r_session->s_mds) {
2873                                 dout("but auth changed, so resending\n");
2874                                 __do_request(mdsc, req);
2875                                 mutex_unlock(&mdsc->mutex);
2876                                 goto out;
2877                         }
2878                 }
2879                 dout("have to return ESTALE on request %llu\n", req->r_tid);
2880         }
2881
2882
2883         if (head->safe) {
2884                 set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
2885                 __unregister_request(mdsc, req);
2886
2887                 /* last request during umount? */
2888                 if (mdsc->stopping && !__get_oldest_req(mdsc))
2889                         complete_all(&mdsc->safe_umount_waiters);
2890
2891                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2892                         /*
2893                          * We already handled the unsafe response, now do the
2894                          * cleanup.  No need to examine the response; the MDS
2895                          * doesn't include any result info in the safe
2896                          * response.  And even if it did, there is nothing
2897                          * useful we could do with a revised return value.
2898                          */
2899                         dout("got safe reply %llu, mds%d\n", tid, mds);
2900
2901                         mutex_unlock(&mdsc->mutex);
2902                         goto out;
2903                 }
2904         } else {
2905                 set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
2906                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2907                 if (req->r_unsafe_dir) {
2908                         struct ceph_inode_info *ci =
2909                                         ceph_inode(req->r_unsafe_dir);
2910                         spin_lock(&ci->i_unsafe_lock);
2911                         list_add_tail(&req->r_unsafe_dir_item,
2912                                       &ci->i_unsafe_dirops);
2913                         spin_unlock(&ci->i_unsafe_lock);
2914                 }
2915         }
2916
2917         dout("handle_reply tid %lld result %d\n", tid, result);
2918         rinfo = &req->r_reply_info;
2919         if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
2920                 err = parse_reply_info(msg, rinfo, (u64)-1);
2921         else
2922                 err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2923         mutex_unlock(&mdsc->mutex);
2924
2925         mutex_lock(&session->s_mutex);
2926         if (err < 0) {
2927                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2928                 ceph_msg_dump(msg);
2929                 goto out_err;
2930         }
2931
2932         /* snap trace */
2933         realm = NULL;
2934         if (rinfo->snapblob_len) {
2935                 down_write(&mdsc->snap_rwsem);
2936                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2937                                 rinfo->snapblob + rinfo->snapblob_len,
2938                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2939                                 &realm);
2940                 downgrade_write(&mdsc->snap_rwsem);
2941         } else {
2942                 down_read(&mdsc->snap_rwsem);
2943         }
2944
2945         /* insert trace into our cache */
2946         mutex_lock(&req->r_fill_mutex);
2947         current->journal_info = req;
2948         err = ceph_fill_trace(mdsc->fsc->sb, req);
2949         if (err == 0) {
2950                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2951                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2952                         ceph_readdir_prepopulate(req, req->r_session);
2953         }
2954         current->journal_info = NULL;
2955         mutex_unlock(&req->r_fill_mutex);
2956
2957         up_read(&mdsc->snap_rwsem);
2958         if (realm)
2959                 ceph_put_snap_realm(mdsc, realm);
2960
2961         if (err == 0) {
2962                 if (req->r_target_inode &&
2963                     test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2964                         struct ceph_inode_info *ci =
2965                                 ceph_inode(req->r_target_inode);
2966                         spin_lock(&ci->i_unsafe_lock);
2967                         list_add_tail(&req->r_unsafe_target_item,
2968                                       &ci->i_unsafe_iops);
2969                         spin_unlock(&ci->i_unsafe_lock);
2970                 }
2971
2972                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2973         }
2974 out_err:
2975         mutex_lock(&mdsc->mutex);
2976         if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
2977                 if (err) {
2978                         req->r_err = err;
2979                 } else {
2980                         req->r_reply =  ceph_msg_get(msg);
2981                         set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
2982                 }
2983         } else {
2984                 dout("reply arrived after request %lld was aborted\n", tid);
2985         }
2986         mutex_unlock(&mdsc->mutex);
2987
2988         mutex_unlock(&session->s_mutex);
2989
2990         /* kick calling process */
2991         complete_request(mdsc, req);
2992 out:
2993         ceph_mdsc_put_request(req);
2994         return;
2995 }
2996
2997
2998
2999 /*
3000  * handle mds notification that our request has been forwarded.
3001  */
3002 static void handle_forward(struct ceph_mds_client *mdsc,
3003                            struct ceph_mds_session *session,
3004                            struct ceph_msg *msg)
3005 {
3006         struct ceph_mds_request *req;
3007         u64 tid = le64_to_cpu(msg->hdr.tid);
3008         u32 next_mds;
3009         u32 fwd_seq;
3010         int err = -EINVAL;
3011         void *p = msg->front.iov_base;
3012         void *end = p + msg->front.iov_len;
3013
3014         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
3015         next_mds = ceph_decode_32(&p);
3016         fwd_seq = ceph_decode_32(&p);
3017
3018         mutex_lock(&mdsc->mutex);
3019         req = lookup_get_request(mdsc, tid);
3020         if (!req) {
3021                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
3022                 goto out;  /* dup reply? */
3023         }
3024
3025         if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3026                 dout("forward tid %llu aborted, unregistering\n", tid);
3027                 __unregister_request(mdsc, req);
3028         } else if (fwd_seq <= req->r_num_fwd) {
3029                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
3030                      tid, next_mds, req->r_num_fwd, fwd_seq);
3031         } else {
3032                 /* resend. forward race not possible; mds would drop */
3033                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
3034                 BUG_ON(req->r_err);
3035                 BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
3036                 req->r_attempts = 0;
3037                 req->r_num_fwd = fwd_seq;
3038                 req->r_resend_mds = next_mds;
3039                 put_request_session(req);
3040                 __do_request(mdsc, req);
3041         }
3042         ceph_mdsc_put_request(req);
3043 out:
3044         mutex_unlock(&mdsc->mutex);
3045         return;
3046
3047 bad:
3048         pr_err("mdsc_handle_forward decode error err=%d\n", err);
3049 }
3050
3051 static int __decode_session_metadata(void **p, void *end,
3052                                      bool *blacklisted)
3053 {
3054         /* map<string,string> */
3055         u32 n;
3056         bool err_str;
3057         ceph_decode_32_safe(p, end, n, bad);
3058         while (n-- > 0) {
3059                 u32 len;
3060                 ceph_decode_32_safe(p, end, len, bad);
3061                 ceph_decode_need(p, end, len, bad);
3062                 err_str = !strncmp(*p, "error_string", len);
3063                 *p += len;
3064                 ceph_decode_32_safe(p, end, len, bad);
3065                 ceph_decode_need(p, end, len, bad);
3066                 if (err_str && strnstr(*p, "blacklisted", len))
3067                         *blacklisted = true;
3068                 *p += len;
3069         }
3070         return 0;
3071 bad:
3072         return -1;
3073 }
3074
3075 /*
3076  * handle a mds session control message
3077  */
3078 static void handle_session(struct ceph_mds_session *session,
3079                            struct ceph_msg *msg)
3080 {
3081         struct ceph_mds_client *mdsc = session->s_mdsc;
3082         int mds = session->s_mds;
3083         int msg_version = le16_to_cpu(msg->hdr.version);
3084         void *p = msg->front.iov_base;
3085         void *end = p + msg->front.iov_len;
3086         struct ceph_mds_session_head *h;
3087         u32 op;
3088         u64 seq;
3089         unsigned long features = 0;
3090         int wake = 0;
3091         bool blacklisted = false;
3092
3093         /* decode */
3094         ceph_decode_need(&p, end, sizeof(*h), bad);
3095         h = p;
3096         p += sizeof(*h);
3097
3098         op = le32_to_cpu(h->op);
3099         seq = le64_to_cpu(h->seq);
3100
3101         if (msg_version >= 3) {
3102                 u32 len;
3103                 /* version >= 2, metadata */
3104                 if (__decode_session_metadata(&p, end, &blacklisted) < 0)
3105                         goto bad;
3106                 /* version >= 3, feature bits */
3107                 ceph_decode_32_safe(&p, end, len, bad);
3108                 ceph_decode_need(&p, end, len, bad);
3109                 memcpy(&features, p, min_t(size_t, len, sizeof(features)));
3110                 p += len;
3111         }
3112
3113         mutex_lock(&mdsc->mutex);
3114         if (op == CEPH_SESSION_CLOSE) {
3115                 get_session(session);
3116                 __unregister_session(mdsc, session);
3117         }
3118         /* FIXME: this ttl calculation is generous */
3119         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
3120         mutex_unlock(&mdsc->mutex);
3121
3122         mutex_lock(&session->s_mutex);
3123
3124         dout("handle_session mds%d %s %p state %s seq %llu\n",
3125              mds, ceph_session_op_name(op), session,
3126              ceph_session_state_name(session->s_state), seq);
3127
3128         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
3129                 session->s_state = CEPH_MDS_SESSION_OPEN;
3130                 pr_info("mds%d came back\n", session->s_mds);
3131         }
3132
3133         switch (op) {
3134         case CEPH_SESSION_OPEN:
3135                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3136                         pr_info("mds%d reconnect success\n", session->s_mds);
3137                 session->s_state = CEPH_MDS_SESSION_OPEN;
3138                 session->s_features = features;
3139                 renewed_caps(mdsc, session, 0);
3140                 wake = 1;
3141                 if (mdsc->stopping)
3142                         __close_session(mdsc, session);
3143                 break;
3144
3145         case CEPH_SESSION_RENEWCAPS:
3146                 if (session->s_renew_seq == seq)
3147                         renewed_caps(mdsc, session, 1);
3148                 break;
3149
3150         case CEPH_SESSION_CLOSE:
3151                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3152                         pr_info("mds%d reconnect denied\n", session->s_mds);
3153                 cleanup_session_requests(mdsc, session);
3154                 remove_session_caps(session);
3155                 wake = 2; /* for good measure */
3156                 wake_up_all(&mdsc->session_close_wq);
3157                 break;
3158
3159         case CEPH_SESSION_STALE:
3160                 pr_info("mds%d caps went stale, renewing\n",
3161                         session->s_mds);
3162                 spin_lock(&session->s_gen_ttl_lock);
3163                 session->s_cap_gen++;
3164                 session->s_cap_ttl = jiffies - 1;
3165                 spin_unlock(&session->s_gen_ttl_lock);
3166                 send_renew_caps(mdsc, session);
3167                 break;
3168
3169         case CEPH_SESSION_RECALL_STATE:
3170                 ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
3171                 break;
3172
3173         case CEPH_SESSION_FLUSHMSG:
3174                 send_flushmsg_ack(mdsc, session, seq);
3175                 break;
3176
3177         case CEPH_SESSION_FORCE_RO:
3178                 dout("force_session_readonly %p\n", session);
3179                 spin_lock(&session->s_cap_lock);
3180                 session->s_readonly = true;
3181                 spin_unlock(&session->s_cap_lock);
3182                 wake_up_session_caps(session, FORCE_RO);
3183                 break;
3184
3185         case CEPH_SESSION_REJECT:
3186                 WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
3187                 pr_info("mds%d rejected session\n", session->s_mds);
3188                 session->s_state = CEPH_MDS_SESSION_REJECTED;
3189                 cleanup_session_requests(mdsc, session);
3190                 remove_session_caps(session);
3191                 if (blacklisted)
3192                         mdsc->fsc->blacklisted = true;
3193                 wake = 2; /* for good measure */
3194                 break;
3195
3196         default:
3197                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
3198                 WARN_ON(1);
3199         }
3200
3201         mutex_unlock(&session->s_mutex);
3202         if (wake) {
3203                 mutex_lock(&mdsc->mutex);
3204                 __wake_requests(mdsc, &session->s_waiting);
3205                 if (wake == 2)
3206                         kick_requests(mdsc, mds);
3207                 mutex_unlock(&mdsc->mutex);
3208         }
3209         if (op == CEPH_SESSION_CLOSE)
3210                 ceph_put_mds_session(session);
3211         return;
3212
3213 bad:
3214         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
3215                (int)msg->front.iov_len);
3216         ceph_msg_dump(msg);
3217         return;
3218 }
3219
3220
3221 /*
3222  * called under session->mutex.
3223  */
3224 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
3225                                    struct ceph_mds_session *session)
3226 {
3227         struct ceph_mds_request *req, *nreq;
3228         struct rb_node *p;
3229         int err;
3230
3231         dout("replay_unsafe_requests mds%d\n", session->s_mds);
3232
3233         mutex_lock(&mdsc->mutex);
3234         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
3235                 err = __prepare_send_request(mdsc, req, session->s_mds, true);
3236                 if (!err) {
3237                         ceph_msg_get(req->r_request);
3238                         ceph_con_send(&session->s_con, req->r_request);
3239                 }
3240         }
3241
3242         /*
3243          * also re-send old requests when MDS enters reconnect stage. So that MDS
3244          * can process completed request in clientreplay stage.
3245          */
3246         p = rb_first(&mdsc->request_tree);
3247         while (p) {
3248                 req = rb_entry(p, struct ceph_mds_request, r_node);
3249                 p = rb_next(p);
3250                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3251                         continue;
3252                 if (req->r_attempts == 0)
3253                         continue; /* only old requests */
3254                 if (req->r_session &&
3255                     req->r_session->s_mds == session->s_mds) {
3256                         err = __prepare_send_request(mdsc, req,
3257                                                      session->s_mds, true);
3258                         if (!err) {
3259                                 ceph_msg_get(req->r_request);
3260                                 ceph_con_send(&session->s_con, req->r_request);
3261                         }
3262                 }
3263         }
3264         mutex_unlock(&mdsc->mutex);
3265 }
3266
3267 static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
3268 {
3269         struct ceph_msg *reply;
3270         struct ceph_pagelist *_pagelist;
3271         struct page *page;
3272         __le32 *addr;
3273         int err = -ENOMEM;
3274
3275         if (!recon_state->allow_multi)
3276                 return -ENOSPC;
3277
3278         /* can't handle message that contains both caps and realm */
3279         BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3280
3281         /* pre-allocate new pagelist */
3282         _pagelist = ceph_pagelist_alloc(GFP_NOFS);
3283         if (!_pagelist)
3284                 return -ENOMEM;
3285
3286         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3287         if (!reply)
3288                 goto fail_msg;
3289
3290         /* placeholder for nr_caps */
3291         err = ceph_pagelist_encode_32(_pagelist, 0);
3292         if (err < 0)
3293                 goto fail;
3294
3295         if (recon_state->nr_caps) {
3296                 /* currently encoding caps */
3297                 err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3298                 if (err)
3299                         goto fail;
3300         } else {
3301                 /* placeholder for nr_realms (currently encoding relams) */
3302                 err = ceph_pagelist_encode_32(_pagelist, 0);
3303                 if (err < 0)
3304                         goto fail;
3305         }
3306
3307         err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3308         if (err)
3309                 goto fail;
3310
3311         page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3312         addr = kmap_atomic(page);
3313         if (recon_state->nr_caps) {
3314                 /* currently encoding caps */
3315                 *addr = cpu_to_le32(recon_state->nr_caps);
3316         } else {
3317                 /* currently encoding relams */
3318                 *(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3319         }
3320         kunmap_atomic(addr);
3321
3322         reply->hdr.version = cpu_to_le16(5);
3323         reply->hdr.compat_version = cpu_to_le16(4);
3324
3325         reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3326         ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3327
3328         ceph_con_send(&recon_state->session->s_con, reply);
3329         ceph_pagelist_release(recon_state->pagelist);
3330
3331         recon_state->pagelist = _pagelist;
3332         recon_state->nr_caps = 0;
3333         recon_state->nr_realms = 0;
3334         recon_state->msg_version = 5;
3335         return 0;
3336 fail:
3337         ceph_msg_put(reply);
3338 fail_msg:
3339         ceph_pagelist_release(_pagelist);
3340         return err;
3341 }
3342
3343 /*
3344  * Encode information about a cap for a reconnect with the MDS.
3345  */
3346 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
3347                           void *arg)
3348 {
3349         union {
3350                 struct ceph_mds_cap_reconnect v2;
3351                 struct ceph_mds_cap_reconnect_v1 v1;
3352         } rec;
3353         struct ceph_inode_info *ci = cap->ci;
3354         struct ceph_reconnect_state *recon_state = arg;
3355         struct ceph_pagelist *pagelist = recon_state->pagelist;
3356         int err;
3357         u64 snap_follows;
3358
3359         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3360              inode, ceph_vinop(inode), cap, cap->cap_id,
3361              ceph_cap_string(cap->issued));
3362
3363         spin_lock(&ci->i_ceph_lock);
3364         cap->seq = 0;        /* reset cap seq */
3365         cap->issue_seq = 0;  /* and issue_seq */
3366         cap->mseq = 0;       /* and migrate_seq */
3367         cap->cap_gen = cap->session->s_cap_gen;
3368
3369         if (recon_state->msg_version >= 2) {
3370                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3371                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3372                 rec.v2.issued = cpu_to_le32(cap->issued);
3373                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3374                 rec.v2.pathbase = 0;
3375                 rec.v2.flock_len = (__force __le32)
3376                         ((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3377         } else {
3378                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3379                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3380                 rec.v1.issued = cpu_to_le32(cap->issued);
3381                 rec.v1.size = cpu_to_le64(inode->i_size);
3382                 ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3383                 ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3384                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3385                 rec.v1.pathbase = 0;
3386         }
3387
3388         if (list_empty(&ci->i_cap_snaps)) {
3389                 snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3390         } else {
3391                 struct ceph_cap_snap *capsnap =
3392                         list_first_entry(&ci->i_cap_snaps,
3393                                          struct ceph_cap_snap, ci_item);
3394                 snap_follows = capsnap->follows;
3395         }
3396         spin_unlock(&ci->i_ceph_lock);
3397
3398         if (recon_state->msg_version >= 2) {
3399                 int num_fcntl_locks, num_flock_locks;
3400                 struct ceph_filelock *flocks = NULL;
3401                 size_t struct_len, total_len = sizeof(u64);
3402                 u8 struct_v = 0;
3403
3404 encode_again:
3405                 if (rec.v2.flock_len) {
3406                         ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
3407                 } else {
3408                         num_fcntl_locks = 0;
3409                         num_flock_locks = 0;
3410                 }
3411                 if (num_fcntl_locks + num_flock_locks > 0) {
3412                         flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
3413                                                sizeof(struct ceph_filelock),
3414                                                GFP_NOFS);
3415                         if (!flocks) {
3416                                 err = -ENOMEM;
3417                                 goto out_err;
3418                         }
3419                         err = ceph_encode_locks_to_buffer(inode, flocks,
3420                                                           num_fcntl_locks,
3421                                                           num_flock_locks);
3422                         if (err) {
3423                                 kfree(flocks);
3424                                 flocks = NULL;
3425                                 if (err == -ENOSPC)
3426                                         goto encode_again;
3427                                 goto out_err;
3428                         }
3429                 } else {
3430                         kfree(flocks);
3431                         flocks = NULL;
3432                 }
3433
3434                 if (recon_state->msg_version >= 3) {
3435                         /* version, compat_version and struct_len */
3436                         total_len += 2 * sizeof(u8) + sizeof(u32);
3437                         struct_v = 2;
3438                 }
3439                 /*
3440                  * number of encoded locks is stable, so copy to pagelist
3441                  */
3442                 struct_len = 2 * sizeof(u32) +
3443                             (num_fcntl_locks + num_flock_locks) *
3444                             sizeof(struct ceph_filelock);
3445                 rec.v2.flock_len = cpu_to_le32(struct_len);
3446
3447                 struct_len += sizeof(u32) + sizeof(rec.v2);
3448
3449                 if (struct_v >= 2)
3450                         struct_len += sizeof(u64); /* snap_follows */
3451
3452                 total_len += struct_len;
3453
3454                 if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
3455                         err = send_reconnect_partial(recon_state);
3456                         if (err)
3457                                 goto out_freeflocks;
3458                         pagelist = recon_state->pagelist;
3459                 }
3460
3461                 err = ceph_pagelist_reserve(pagelist, total_len);
3462                 if (err)
3463                         goto out_freeflocks;
3464
3465                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3466                 if (recon_state->msg_version >= 3) {
3467                         ceph_pagelist_encode_8(pagelist, struct_v);
3468                         ceph_pagelist_encode_8(pagelist, 1);
3469                         ceph_pagelist_encode_32(pagelist, struct_len);
3470                 }
3471                 ceph_pagelist_encode_string(pagelist, NULL, 0);
3472                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
3473                 ceph_locks_to_pagelist(flocks, pagelist,
3474                                        num_fcntl_locks, num_flock_locks);
3475                 if (struct_v >= 2)
3476                         ceph_pagelist_encode_64(pagelist, snap_follows);
3477 out_freeflocks:
3478                 kfree(flocks);
3479         } else {
3480                 u64 pathbase = 0;
3481                 int pathlen = 0;
3482                 char *path = NULL;
3483                 struct dentry *dentry;
3484
3485                 dentry = d_find_alias(inode);
3486                 if (dentry) {
3487                         path = ceph_mdsc_build_path(dentry,
3488                                                 &pathlen, &pathbase, 0);
3489                         dput(dentry);
3490                         if (IS_ERR(path)) {
3491                                 err = PTR_ERR(path);
3492                                 goto out_err;
3493                         }
3494                         rec.v1.pathbase = cpu_to_le64(pathbase);
3495                 }
3496
3497                 err = ceph_pagelist_reserve(pagelist,
3498                                             sizeof(u64) + sizeof(u32) +
3499                                             pathlen + sizeof(rec.v1));
3500                 if (err) {
3501                         goto out_freepath;
3502                 }
3503
3504                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3505                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3506                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
3507 out_freepath:
3508                 ceph_mdsc_free_path(path, pathlen);
3509         }
3510
3511 out_err:
3512         if (err >= 0)
3513                 recon_state->nr_caps++;
3514         return err;
3515 }
3516
3517 static int encode_snap_realms(struct ceph_mds_client *mdsc,
3518                               struct ceph_reconnect_state *recon_state)
3519 {
3520         struct rb_node *p;
3521         struct ceph_pagelist *pagelist = recon_state->pagelist;
3522         int err = 0;
3523
3524         if (recon_state->msg_version >= 4) {
3525                 err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
3526                 if (err < 0)
3527                         goto fail;
3528         }
3529
3530         /*
3531          * snaprealms.  we provide mds with the ino, seq (version), and
3532          * parent for all of our realms.  If the mds has any newer info,
3533          * it will tell us.
3534          */
3535         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3536                 struct ceph_snap_realm *realm =
3537                        rb_entry(p, struct ceph_snap_realm, node);
3538                 struct ceph_mds_snaprealm_reconnect sr_rec;
3539
3540                 if (recon_state->msg_version >= 4) {
3541                         size_t need = sizeof(u8) * 2 + sizeof(u32) +
3542                                       sizeof(sr_rec);
3543
3544                         if (pagelist->length + need > RECONNECT_MAX_SIZE) {
3545                                 err = send_reconnect_partial(recon_state);
3546                                 if (err)
3547                                         goto fail;
3548                                 pagelist = recon_state->pagelist;
3549                         }
3550
3551                         err = ceph_pagelist_reserve(pagelist, need);
3552                         if (err)
3553                                 goto fail;
3554
3555                         ceph_pagelist_encode_8(pagelist, 1);
3556                         ceph_pagelist_encode_8(pagelist, 1);
3557                         ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
3558                 }
3559
3560                 dout(" adding snap realm %llx seq %lld parent %llx\n",
3561                      realm->ino, realm->seq, realm->parent_ino);
3562                 sr_rec.ino = cpu_to_le64(realm->ino);
3563                 sr_rec.seq = cpu_to_le64(realm->seq);
3564                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
3565
3566                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3567                 if (err)
3568                         goto fail;
3569
3570                 recon_state->nr_realms++;
3571         }
3572 fail:
3573         return err;
3574 }
3575
3576
3577 /*
3578  * If an MDS fails and recovers, clients need to reconnect in order to
3579  * reestablish shared state.  This includes all caps issued through
3580  * this session _and_ the snap_realm hierarchy.  Because it's not
3581  * clear which snap realms the mds cares about, we send everything we
3582  * know about.. that ensures we'll then get any new info the
3583  * recovering MDS might have.
3584  *
3585  * This is a relatively heavyweight operation, but it's rare.
3586  *
3587  * called with mdsc->mutex held.
3588  */
3589 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
3590                                struct ceph_mds_session *session)
3591 {
3592         struct ceph_msg *reply;
3593         int mds = session->s_mds;
3594         int err = -ENOMEM;
3595         struct ceph_reconnect_state recon_state = {
3596                 .session = session,
3597         };
3598         LIST_HEAD(dispose);
3599
3600         pr_info("mds%d reconnect start\n", mds);
3601
3602         recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
3603         if (!recon_state.pagelist)
3604                 goto fail_nopagelist;
3605
3606         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3607         if (!reply)
3608                 goto fail_nomsg;
3609
3610         mutex_lock(&session->s_mutex);
3611         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
3612         session->s_seq = 0;
3613
3614         dout("session %p state %s\n", session,
3615              ceph_session_state_name(session->s_state));
3616
3617         spin_lock(&session->s_gen_ttl_lock);
3618         session->s_cap_gen++;
3619         spin_unlock(&session->s_gen_ttl_lock);
3620
3621         spin_lock(&session->s_cap_lock);
3622         /* don't know if session is readonly */
3623         session->s_readonly = 0;
3624         /*
3625          * notify __ceph_remove_cap() that we are composing cap reconnect.
3626          * If a cap get released before being added to the cap reconnect,
3627          * __ceph_remove_cap() should skip queuing cap release.
3628          */
3629         session->s_cap_reconnect = 1;
3630         /* drop old cap expires; we're about to reestablish that state */
3631         detach_cap_releases(session, &dispose);
3632         spin_unlock(&session->s_cap_lock);
3633         dispose_cap_releases(mdsc, &dispose);
3634
3635         /* trim unused caps to reduce MDS's cache rejoin time */
3636         if (mdsc->fsc->sb->s_root)
3637                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
3638
3639         ceph_con_close(&session->s_con);
3640         ceph_con_open(&session->s_con,
3641                       CEPH_ENTITY_TYPE_MDS, mds,
3642                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
3643
3644         /* replay unsafe requests */
3645         replay_unsafe_requests(mdsc, session);
3646
3647         ceph_early_kick_flushing_caps(mdsc, session);
3648
3649         down_read(&mdsc->snap_rwsem);
3650
3651         /* placeholder for nr_caps */
3652         err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
3653         if (err)
3654                 goto fail;
3655
3656         if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
3657                 recon_state.msg_version = 3;
3658                 recon_state.allow_multi = true;
3659         } else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
3660                 recon_state.msg_version = 3;
3661         } else {
3662                 recon_state.msg_version = 2;
3663         }
3664         /* trsaverse this session's caps */
3665         err = ceph_iterate_session_caps(session, encode_caps_cb, &recon_state);
3666
3667         spin_lock(&session->s_cap_lock);
3668         session->s_cap_reconnect = 0;
3669         spin_unlock(&session->s_cap_lock);
3670
3671         if (err < 0)
3672                 goto fail;
3673
3674         /* check if all realms can be encoded into current message */
3675         if (mdsc->num_snap_realms) {
3676                 size_t total_len =
3677                         recon_state.pagelist->length +
3678                         mdsc->num_snap_realms *
3679                         sizeof(struct ceph_mds_snaprealm_reconnect);
3680                 if (recon_state.msg_version >= 4) {
3681                         /* number of realms */
3682                         total_len += sizeof(u32);
3683                         /* version, compat_version and struct_len */
3684                         total_len += mdsc->num_snap_realms *
3685                                      (2 * sizeof(u8) + sizeof(u32));
3686                 }
3687                 if (total_len > RECONNECT_MAX_SIZE) {
3688                         if (!recon_state.allow_multi) {
3689                                 err = -ENOSPC;
3690                                 goto fail;
3691                         }
3692                         if (recon_state.nr_caps) {
3693                                 err = send_reconnect_partial(&recon_state);
3694                                 if (err)
3695                                         goto fail;
3696                         }
3697                         recon_state.msg_version = 5;
3698                 }
3699         }
3700
3701         err = encode_snap_realms(mdsc, &recon_state);
3702         if (err < 0)
3703                 goto fail;
3704
3705         if (recon_state.msg_version >= 5) {
3706                 err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
3707                 if (err < 0)
3708                         goto fail;
3709         }
3710
3711         if (recon_state.nr_caps || recon_state.nr_realms) {
3712                 struct page *page =
3713                         list_first_entry(&recon_state.pagelist->head,
3714                                         struct page, lru);
3715                 __le32 *addr = kmap_atomic(page);
3716                 if (recon_state.nr_caps) {
3717                         WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
3718                         *addr = cpu_to_le32(recon_state.nr_caps);
3719                 } else if (recon_state.msg_version >= 4) {
3720                         *(addr + 1) = cpu_to_le32(recon_state.nr_realms);
3721                 }
3722                 kunmap_atomic(addr);
3723         }
3724
3725         reply->hdr.version = cpu_to_le16(recon_state.msg_version);
3726         if (recon_state.msg_version >= 4)
3727                 reply->hdr.compat_version = cpu_to_le16(4);
3728
3729         reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
3730         ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
3731
3732         ceph_con_send(&session->s_con, reply);
3733
3734         mutex_unlock(&session->s_mutex);
3735
3736         mutex_lock(&mdsc->mutex);
3737         __wake_requests(mdsc, &session->s_waiting);
3738         mutex_unlock(&mdsc->mutex);
3739
3740         up_read(&mdsc->snap_rwsem);
3741         ceph_pagelist_release(recon_state.pagelist);
3742         return;
3743
3744 fail:
3745         ceph_msg_put(reply);
3746         up_read(&mdsc->snap_rwsem);
3747         mutex_unlock(&session->s_mutex);
3748 fail_nomsg:
3749         ceph_pagelist_release(recon_state.pagelist);
3750 fail_nopagelist:
3751         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3752         return;
3753 }
3754
3755
3756 /*
3757  * compare old and new mdsmaps, kicking requests
3758  * and closing out old connections as necessary
3759  *
3760  * called under mdsc->mutex.
3761  */
3762 static void check_new_map(struct ceph_mds_client *mdsc,
3763                           struct ceph_mdsmap *newmap,
3764                           struct ceph_mdsmap *oldmap)
3765 {
3766         int i;
3767         int oldstate, newstate;
3768         struct ceph_mds_session *s;
3769
3770         dout("check_new_map new %u old %u\n",
3771              newmap->m_epoch, oldmap->m_epoch);
3772
3773         for (i = 0; i < oldmap->m_num_mds && i < mdsc->max_sessions; i++) {
3774                 if (!mdsc->sessions[i])
3775                         continue;
3776                 s = mdsc->sessions[i];
3777                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3778                 newstate = ceph_mdsmap_get_state(newmap, i);
3779
3780                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3781                      i, ceph_mds_state_name(oldstate),
3782                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3783                      ceph_mds_state_name(newstate),
3784                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3785                      ceph_session_state_name(s->s_state));
3786
3787                 if (i >= newmap->m_num_mds) {
3788                         /* force close session for stopped mds */
3789                         get_session(s);
3790                         __unregister_session(mdsc, s);
3791                         __wake_requests(mdsc, &s->s_waiting);
3792                         mutex_unlock(&mdsc->mutex);
3793
3794                         mutex_lock(&s->s_mutex);
3795                         cleanup_session_requests(mdsc, s);
3796                         remove_session_caps(s);
3797                         mutex_unlock(&s->s_mutex);
3798
3799                         ceph_put_mds_session(s);
3800
3801                         mutex_lock(&mdsc->mutex);
3802                         kick_requests(mdsc, i);
3803                         continue;
3804                 }
3805
3806                 if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
3807                            ceph_mdsmap_get_addr(newmap, i),
3808                            sizeof(struct ceph_entity_addr))) {
3809                         /* just close it */
3810                         mutex_unlock(&mdsc->mutex);
3811                         mutex_lock(&s->s_mutex);
3812                         mutex_lock(&mdsc->mutex);
3813                         ceph_con_close(&s->s_con);
3814                         mutex_unlock(&s->s_mutex);
3815                         s->s_state = CEPH_MDS_SESSION_RESTARTING;
3816                 } else if (oldstate == newstate) {
3817                         continue;  /* nothing new with this mds */
3818                 }
3819
3820                 /*
3821                  * send reconnect?
3822                  */
3823                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3824                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3825                         mutex_unlock(&mdsc->mutex);
3826                         send_mds_reconnect(mdsc, s);
3827                         mutex_lock(&mdsc->mutex);
3828                 }
3829
3830                 /*
3831                  * kick request on any mds that has gone active.
3832                  */
3833                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3834                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3835                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3836                             oldstate != CEPH_MDS_STATE_STARTING)
3837                                 pr_info("mds%d recovery completed\n", s->s_mds);
3838                         kick_requests(mdsc, i);
3839                         ceph_kick_flushing_caps(mdsc, s);
3840                         wake_up_session_caps(s, RECONNECT);
3841                 }
3842         }
3843
3844         for (i = 0; i < newmap->m_num_mds && i < mdsc->max_sessions; i++) {
3845                 s = mdsc->sessions[i];
3846                 if (!s)
3847                         continue;
3848                 if (!ceph_mdsmap_is_laggy(newmap, i))
3849                         continue;
3850                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3851                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3852                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3853                         dout(" connecting to export targets of laggy mds%d\n",
3854                              i);
3855                         __open_export_target_sessions(mdsc, s);
3856                 }
3857         }
3858 }
3859
3860
3861
3862 /*
3863  * leases
3864  */
3865
3866 /*
3867  * caller must hold session s_mutex, dentry->d_lock
3868  */
3869 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3870 {
3871         struct ceph_dentry_info *di = ceph_dentry(dentry);
3872
3873         ceph_put_mds_session(di->lease_session);
3874         di->lease_session = NULL;
3875 }
3876
3877 static void handle_lease(struct ceph_mds_client *mdsc,
3878                          struct ceph_mds_session *session,
3879                          struct ceph_msg *msg)
3880 {
3881         struct super_block *sb = mdsc->fsc->sb;
3882         struct inode *inode;
3883         struct dentry *parent, *dentry;
3884         struct ceph_dentry_info *di;
3885         int mds = session->s_mds;
3886         struct ceph_mds_lease *h = msg->front.iov_base;
3887         u32 seq;
3888         struct ceph_vino vino;
3889         struct qstr dname;
3890         int release = 0;
3891
3892         dout("handle_lease from mds%d\n", mds);
3893
3894         /* decode */
3895         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3896                 goto bad;
3897         vino.ino = le64_to_cpu(h->ino);
3898         vino.snap = CEPH_NOSNAP;
3899         seq = le32_to_cpu(h->seq);
3900         dname.len = get_unaligned_le32(h + 1);
3901         if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
3902                 goto bad;
3903         dname.name = (void *)(h + 1) + sizeof(u32);
3904
3905         /* lookup inode */
3906         inode = ceph_find_inode(sb, vino);
3907         dout("handle_lease %s, ino %llx %p %.*s\n",
3908              ceph_lease_op_name(h->action), vino.ino, inode,
3909              dname.len, dname.name);
3910
3911         mutex_lock(&session->s_mutex);
3912         session->s_seq++;
3913
3914         if (!inode) {
3915                 dout("handle_lease no inode %llx\n", vino.ino);
3916                 goto release;
3917         }
3918
3919         /* dentry */
3920         parent = d_find_alias(inode);
3921         if (!parent) {
3922                 dout("no parent dentry on inode %p\n", inode);
3923                 WARN_ON(1);
3924                 goto release;  /* hrm... */
3925         }
3926         dname.hash = full_name_hash(parent, dname.name, dname.len);
3927         dentry = d_lookup(parent, &dname);
3928         dput(parent);
3929         if (!dentry)
3930                 goto release;
3931
3932         spin_lock(&dentry->d_lock);
3933         di = ceph_dentry(dentry);
3934         switch (h->action) {
3935         case CEPH_MDS_LEASE_REVOKE:
3936                 if (di->lease_session == session) {
3937                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3938                                 h->seq = cpu_to_le32(di->lease_seq);
3939                         __ceph_mdsc_drop_dentry_lease(dentry);
3940                 }
3941                 release = 1;
3942                 break;
3943
3944         case CEPH_MDS_LEASE_RENEW:
3945                 if (di->lease_session == session &&
3946                     di->lease_gen == session->s_cap_gen &&
3947                     di->lease_renew_from &&
3948                     di->lease_renew_after == 0) {
3949                         unsigned long duration =
3950                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3951
3952                         di->lease_seq = seq;
3953                         di->time = di->lease_renew_from + duration;
3954                         di->lease_renew_after = di->lease_renew_from +
3955                                 (duration >> 1);
3956                         di->lease_renew_from = 0;
3957                 }
3958                 break;
3959         }
3960         spin_unlock(&dentry->d_lock);
3961         dput(dentry);
3962
3963         if (!release)
3964                 goto out;
3965
3966 release:
3967         /* let's just reuse the same message */
3968         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3969         ceph_msg_get(msg);
3970         ceph_con_send(&session->s_con, msg);
3971
3972 out:
3973         mutex_unlock(&session->s_mutex);
3974         /* avoid calling iput_final() in mds dispatch threads */
3975         ceph_async_iput(inode);
3976         return;
3977
3978 bad:
3979         pr_err("corrupt lease message\n");
3980         ceph_msg_dump(msg);
3981 }
3982
3983 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3984                               struct dentry *dentry, char action,
3985                               u32 seq)
3986 {
3987         struct ceph_msg *msg;
3988         struct ceph_mds_lease *lease;
3989         struct inode *dir;
3990         int len = sizeof(*lease) + sizeof(u32) + NAME_MAX;
3991
3992         dout("lease_send_msg identry %p %s to mds%d\n",
3993              dentry, ceph_lease_op_name(action), session->s_mds);
3994
3995         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
3996         if (!msg)
3997                 return;
3998         lease = msg->front.iov_base;
3999         lease->action = action;
4000         lease->seq = cpu_to_le32(seq);
4001
4002         spin_lock(&dentry->d_lock);
4003         dir = d_inode(dentry->d_parent);
4004         lease->ino = cpu_to_le64(ceph_ino(dir));
4005         lease->first = lease->last = cpu_to_le64(ceph_snap(dir));
4006
4007         put_unaligned_le32(dentry->d_name.len, lease + 1);
4008         memcpy((void *)(lease + 1) + 4,
4009                dentry->d_name.name, dentry->d_name.len);
4010         spin_unlock(&dentry->d_lock);
4011         /*
4012          * if this is a preemptive lease RELEASE, no need to
4013          * flush request stream, since the actual request will
4014          * soon follow.
4015          */
4016         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
4017
4018         ceph_con_send(&session->s_con, msg);
4019 }
4020
4021 /*
4022  * lock unlock sessions, to wait ongoing session activities
4023  */
4024 static void lock_unlock_sessions(struct ceph_mds_client *mdsc)
4025 {
4026         int i;
4027
4028         mutex_lock(&mdsc->mutex);
4029         for (i = 0; i < mdsc->max_sessions; i++) {
4030                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4031                 if (!s)
4032                         continue;
4033                 mutex_unlock(&mdsc->mutex);
4034                 mutex_lock(&s->s_mutex);
4035                 mutex_unlock(&s->s_mutex);
4036                 ceph_put_mds_session(s);
4037                 mutex_lock(&mdsc->mutex);
4038         }
4039         mutex_unlock(&mdsc->mutex);
4040 }
4041
4042 static void maybe_recover_session(struct ceph_mds_client *mdsc)
4043 {
4044         struct ceph_fs_client *fsc = mdsc->fsc;
4045
4046         if (!ceph_test_mount_opt(fsc, CLEANRECOVER))
4047                 return;
4048
4049         if (READ_ONCE(fsc->mount_state) != CEPH_MOUNT_MOUNTED)
4050                 return;
4051
4052         if (!READ_ONCE(fsc->blacklisted))
4053                 return;
4054
4055         if (fsc->last_auto_reconnect &&
4056             time_before(jiffies, fsc->last_auto_reconnect + HZ * 60 * 30))
4057                 return;
4058
4059         pr_info("auto reconnect after blacklisted\n");
4060         fsc->last_auto_reconnect = jiffies;
4061         ceph_force_reconnect(fsc->sb);
4062 }
4063
4064 /*
4065  * delayed work -- periodically trim expired leases, renew caps with mds
4066  */
4067 static void schedule_delayed(struct ceph_mds_client *mdsc)
4068 {
4069         int delay = 5;
4070         unsigned hz = round_jiffies_relative(HZ * delay);
4071         schedule_delayed_work(&mdsc->delayed_work, hz);
4072 }
4073
4074 static void delayed_work(struct work_struct *work)
4075 {
4076         int i;
4077         struct ceph_mds_client *mdsc =
4078                 container_of(work, struct ceph_mds_client, delayed_work.work);
4079         int renew_interval;
4080         int renew_caps;
4081
4082         dout("mdsc delayed_work\n");
4083
4084         mutex_lock(&mdsc->mutex);
4085         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
4086         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
4087                                    mdsc->last_renew_caps);
4088         if (renew_caps)
4089                 mdsc->last_renew_caps = jiffies;
4090
4091         for (i = 0; i < mdsc->max_sessions; i++) {
4092                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4093                 if (!s)
4094                         continue;
4095                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
4096                         dout("resending session close request for mds%d\n",
4097                              s->s_mds);
4098                         request_close_session(mdsc, s);
4099                         ceph_put_mds_session(s);
4100                         continue;
4101                 }
4102                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
4103                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
4104                                 s->s_state = CEPH_MDS_SESSION_HUNG;
4105                                 pr_info("mds%d hung\n", s->s_mds);
4106                         }
4107                 }
4108                 if (s->s_state == CEPH_MDS_SESSION_NEW ||
4109                     s->s_state == CEPH_MDS_SESSION_RESTARTING ||
4110                     s->s_state == CEPH_MDS_SESSION_REJECTED) {
4111                         /* this mds is failed or recovering, just wait */
4112                         ceph_put_mds_session(s);
4113                         continue;
4114                 }
4115                 mutex_unlock(&mdsc->mutex);
4116
4117                 mutex_lock(&s->s_mutex);
4118                 if (renew_caps)
4119                         send_renew_caps(mdsc, s);
4120                 else
4121                         ceph_con_keepalive(&s->s_con);
4122                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4123                     s->s_state == CEPH_MDS_SESSION_HUNG)
4124                         ceph_send_cap_releases(mdsc, s);
4125                 mutex_unlock(&s->s_mutex);
4126                 ceph_put_mds_session(s);
4127
4128                 mutex_lock(&mdsc->mutex);
4129         }
4130         mutex_unlock(&mdsc->mutex);
4131
4132         ceph_check_delayed_caps(mdsc);
4133
4134         ceph_queue_cap_reclaim_work(mdsc);
4135
4136         ceph_trim_snapid_map(mdsc);
4137
4138         maybe_recover_session(mdsc);
4139
4140         schedule_delayed(mdsc);
4141 }
4142
4143 int ceph_mdsc_init(struct ceph_fs_client *fsc)
4144
4145 {
4146         struct ceph_mds_client *mdsc;
4147
4148         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
4149         if (!mdsc)
4150                 return -ENOMEM;
4151         mdsc->fsc = fsc;
4152         mutex_init(&mdsc->mutex);
4153         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
4154         if (!mdsc->mdsmap) {
4155                 kfree(mdsc);
4156                 return -ENOMEM;
4157         }
4158
4159         fsc->mdsc = mdsc;
4160         init_completion(&mdsc->safe_umount_waiters);
4161         init_waitqueue_head(&mdsc->session_close_wq);
4162         INIT_LIST_HEAD(&mdsc->waiting_for_map);
4163         mdsc->sessions = NULL;
4164         atomic_set(&mdsc->num_sessions, 0);
4165         mdsc->max_sessions = 0;
4166         mdsc->stopping = 0;
4167         atomic64_set(&mdsc->quotarealms_count, 0);
4168         mdsc->quotarealms_inodes = RB_ROOT;
4169         mutex_init(&mdsc->quotarealms_inodes_mutex);
4170         mdsc->last_snap_seq = 0;
4171         init_rwsem(&mdsc->snap_rwsem);
4172         mdsc->snap_realms = RB_ROOT;
4173         INIT_LIST_HEAD(&mdsc->snap_empty);
4174         mdsc->num_snap_realms = 0;
4175         spin_lock_init(&mdsc->snap_empty_lock);
4176         mdsc->last_tid = 0;
4177         mdsc->oldest_tid = 0;
4178         mdsc->request_tree = RB_ROOT;
4179         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
4180         mdsc->last_renew_caps = jiffies;
4181         INIT_LIST_HEAD(&mdsc->cap_delay_list);
4182         INIT_LIST_HEAD(&mdsc->cap_wait_list);
4183         spin_lock_init(&mdsc->cap_delay_lock);
4184         INIT_LIST_HEAD(&mdsc->snap_flush_list);
4185         spin_lock_init(&mdsc->snap_flush_lock);
4186         mdsc->last_cap_flush_tid = 1;
4187         INIT_LIST_HEAD(&mdsc->cap_flush_list);
4188         INIT_LIST_HEAD(&mdsc->cap_dirty);
4189         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
4190         mdsc->num_cap_flushing = 0;
4191         spin_lock_init(&mdsc->cap_dirty_lock);
4192         init_waitqueue_head(&mdsc->cap_flushing_wq);
4193         INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
4194         atomic_set(&mdsc->cap_reclaim_pending, 0);
4195
4196         spin_lock_init(&mdsc->dentry_list_lock);
4197         INIT_LIST_HEAD(&mdsc->dentry_leases);
4198         INIT_LIST_HEAD(&mdsc->dentry_dir_leases);
4199
4200         ceph_caps_init(mdsc);
4201         ceph_adjust_caps_max_min(mdsc, fsc->mount_options);
4202
4203         spin_lock_init(&mdsc->snapid_map_lock);
4204         mdsc->snapid_map_tree = RB_ROOT;
4205         INIT_LIST_HEAD(&mdsc->snapid_map_lru);
4206
4207         init_rwsem(&mdsc->pool_perm_rwsem);
4208         mdsc->pool_perm_tree = RB_ROOT;
4209
4210         strscpy(mdsc->nodename, utsname()->nodename,
4211                 sizeof(mdsc->nodename));
4212         return 0;
4213 }
4214
4215 /*
4216  * Wait for safe replies on open mds requests.  If we time out, drop
4217  * all requests from the tree to avoid dangling dentry refs.
4218  */
4219 static void wait_requests(struct ceph_mds_client *mdsc)
4220 {
4221         struct ceph_options *opts = mdsc->fsc->client->options;
4222         struct ceph_mds_request *req;
4223
4224         mutex_lock(&mdsc->mutex);
4225         if (__get_oldest_req(mdsc)) {
4226                 mutex_unlock(&mdsc->mutex);
4227
4228                 dout("wait_requests waiting for requests\n");
4229                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
4230                                     ceph_timeout_jiffies(opts->mount_timeout));
4231
4232                 /* tear down remaining requests */
4233                 mutex_lock(&mdsc->mutex);
4234                 while ((req = __get_oldest_req(mdsc))) {
4235                         dout("wait_requests timed out on tid %llu\n",
4236                              req->r_tid);
4237                         list_del_init(&req->r_wait);
4238                         __unregister_request(mdsc, req);
4239                 }
4240         }
4241         mutex_unlock(&mdsc->mutex);
4242         dout("wait_requests done\n");
4243 }
4244
4245 /*
4246  * called before mount is ro, and before dentries are torn down.
4247  * (hmm, does this still race with new lookups?)
4248  */
4249 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
4250 {
4251         dout("pre_umount\n");
4252         mdsc->stopping = 1;
4253
4254         lock_unlock_sessions(mdsc);
4255         ceph_flush_dirty_caps(mdsc);
4256         wait_requests(mdsc);
4257
4258         /*
4259          * wait for reply handlers to drop their request refs and
4260          * their inode/dcache refs
4261          */
4262         ceph_msgr_flush();
4263
4264         ceph_cleanup_quotarealms_inodes(mdsc);
4265 }
4266
4267 /*
4268  * wait for all write mds requests to flush.
4269  */
4270 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
4271 {
4272         struct ceph_mds_request *req = NULL, *nextreq;
4273         struct rb_node *n;
4274
4275         mutex_lock(&mdsc->mutex);
4276         dout("wait_unsafe_requests want %lld\n", want_tid);
4277 restart:
4278         req = __get_oldest_req(mdsc);
4279         while (req && req->r_tid <= want_tid) {
4280                 /* find next request */
4281                 n = rb_next(&req->r_node);
4282                 if (n)
4283                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
4284                 else
4285                         nextreq = NULL;
4286                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
4287                     (req->r_op & CEPH_MDS_OP_WRITE)) {
4288                         /* write op */
4289                         ceph_mdsc_get_request(req);
4290                         if (nextreq)
4291                                 ceph_mdsc_get_request(nextreq);
4292                         mutex_unlock(&mdsc->mutex);
4293                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
4294                              req->r_tid, want_tid);
4295                         wait_for_completion(&req->r_safe_completion);
4296                         mutex_lock(&mdsc->mutex);
4297                         ceph_mdsc_put_request(req);
4298                         if (!nextreq)
4299                                 break;  /* next dne before, so we're done! */
4300                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
4301                                 /* next request was removed from tree */
4302                                 ceph_mdsc_put_request(nextreq);
4303                                 goto restart;
4304                         }
4305                         ceph_mdsc_put_request(nextreq);  /* won't go away */
4306                 }
4307                 req = nextreq;
4308         }
4309         mutex_unlock(&mdsc->mutex);
4310         dout("wait_unsafe_requests done\n");
4311 }
4312
4313 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
4314 {
4315         u64 want_tid, want_flush;
4316
4317         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4318                 return;
4319
4320         dout("sync\n");
4321         mutex_lock(&mdsc->mutex);
4322         want_tid = mdsc->last_tid;
4323         mutex_unlock(&mdsc->mutex);
4324
4325         ceph_flush_dirty_caps(mdsc);
4326         spin_lock(&mdsc->cap_dirty_lock);
4327         want_flush = mdsc->last_cap_flush_tid;
4328         if (!list_empty(&mdsc->cap_flush_list)) {
4329                 struct ceph_cap_flush *cf =
4330                         list_last_entry(&mdsc->cap_flush_list,
4331                                         struct ceph_cap_flush, g_list);
4332                 cf->wake = true;
4333         }
4334         spin_unlock(&mdsc->cap_dirty_lock);
4335
4336         dout("sync want tid %lld flush_seq %lld\n",
4337              want_tid, want_flush);
4338
4339         wait_unsafe_requests(mdsc, want_tid);
4340         wait_caps_flush(mdsc, want_flush);
4341 }
4342
4343 /*
4344  * true if all sessions are closed, or we force unmount
4345  */
4346 static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
4347 {
4348         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4349                 return true;
4350         return atomic_read(&mdsc->num_sessions) <= skipped;
4351 }
4352
4353 /*
4354  * called after sb is ro.
4355  */
4356 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
4357 {
4358         struct ceph_options *opts = mdsc->fsc->client->options;
4359         struct ceph_mds_session *session;
4360         int i;
4361         int skipped = 0;
4362
4363         dout("close_sessions\n");
4364
4365         /* close sessions */
4366         mutex_lock(&mdsc->mutex);
4367         for (i = 0; i < mdsc->max_sessions; i++) {
4368                 session = __ceph_lookup_mds_session(mdsc, i);
4369                 if (!session)
4370                         continue;
4371                 mutex_unlock(&mdsc->mutex);
4372                 mutex_lock(&session->s_mutex);
4373                 if (__close_session(mdsc, session) <= 0)
4374                         skipped++;
4375                 mutex_unlock(&session->s_mutex);
4376                 ceph_put_mds_session(session);
4377                 mutex_lock(&mdsc->mutex);
4378         }
4379         mutex_unlock(&mdsc->mutex);
4380
4381         dout("waiting for sessions to close\n");
4382         wait_event_timeout(mdsc->session_close_wq,
4383                            done_closing_sessions(mdsc, skipped),
4384                            ceph_timeout_jiffies(opts->mount_timeout));
4385
4386         /* tear down remaining sessions */
4387         mutex_lock(&mdsc->mutex);
4388         for (i = 0; i < mdsc->max_sessions; i++) {
4389                 if (mdsc->sessions[i]) {
4390                         session = get_session(mdsc->sessions[i]);
4391                         __unregister_session(mdsc, session);
4392                         mutex_unlock(&mdsc->mutex);
4393                         mutex_lock(&session->s_mutex);
4394                         remove_session_caps(session);
4395                         mutex_unlock(&session->s_mutex);
4396                         ceph_put_mds_session(session);
4397                         mutex_lock(&mdsc->mutex);
4398                 }
4399         }
4400         WARN_ON(!list_empty(&mdsc->cap_delay_list));
4401         mutex_unlock(&mdsc->mutex);
4402
4403         ceph_cleanup_snapid_map(mdsc);
4404         ceph_cleanup_empty_realms(mdsc);
4405
4406         cancel_work_sync(&mdsc->cap_reclaim_work);
4407         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4408
4409         dout("stopped\n");
4410 }
4411
4412 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
4413 {
4414         struct ceph_mds_session *session;
4415         int mds;
4416
4417         dout("force umount\n");
4418
4419         mutex_lock(&mdsc->mutex);
4420         for (mds = 0; mds < mdsc->max_sessions; mds++) {
4421                 session = __ceph_lookup_mds_session(mdsc, mds);
4422                 if (!session)
4423                         continue;
4424
4425                 if (session->s_state == CEPH_MDS_SESSION_REJECTED)
4426                         __unregister_session(mdsc, session);
4427                 __wake_requests(mdsc, &session->s_waiting);
4428                 mutex_unlock(&mdsc->mutex);
4429
4430                 mutex_lock(&session->s_mutex);
4431                 __close_session(mdsc, session);
4432                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
4433                         cleanup_session_requests(mdsc, session);
4434                         remove_session_caps(session);
4435                 }
4436                 mutex_unlock(&session->s_mutex);
4437                 ceph_put_mds_session(session);
4438
4439                 mutex_lock(&mdsc->mutex);
4440                 kick_requests(mdsc, mds);
4441         }
4442         __wake_requests(mdsc, &mdsc->waiting_for_map);
4443         mutex_unlock(&mdsc->mutex);
4444 }
4445
4446 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
4447 {
4448         dout("stop\n");
4449         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4450         if (mdsc->mdsmap)
4451                 ceph_mdsmap_destroy(mdsc->mdsmap);
4452         kfree(mdsc->sessions);
4453         ceph_caps_finalize(mdsc);
4454         ceph_pool_perm_destroy(mdsc);
4455 }
4456
4457 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
4458 {
4459         struct ceph_mds_client *mdsc = fsc->mdsc;
4460         dout("mdsc_destroy %p\n", mdsc);
4461
4462         if (!mdsc)
4463                 return;
4464
4465         /* flush out any connection work with references to us */
4466         ceph_msgr_flush();
4467
4468         ceph_mdsc_stop(mdsc);
4469
4470         fsc->mdsc = NULL;
4471         kfree(mdsc);
4472         dout("mdsc_destroy %p done\n", mdsc);
4473 }
4474
4475 void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4476 {
4477         struct ceph_fs_client *fsc = mdsc->fsc;
4478         const char *mds_namespace = fsc->mount_options->mds_namespace;
4479         void *p = msg->front.iov_base;
4480         void *end = p + msg->front.iov_len;
4481         u32 epoch;
4482         u32 map_len;
4483         u32 num_fs;
4484         u32 mount_fscid = (u32)-1;
4485         u8 struct_v, struct_cv;
4486         int err = -EINVAL;
4487
4488         ceph_decode_need(&p, end, sizeof(u32), bad);
4489         epoch = ceph_decode_32(&p);
4490
4491         dout("handle_fsmap epoch %u\n", epoch);
4492
4493         ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4494         struct_v = ceph_decode_8(&p);
4495         struct_cv = ceph_decode_8(&p);
4496         map_len = ceph_decode_32(&p);
4497
4498         ceph_decode_need(&p, end, sizeof(u32) * 3, bad);
4499         p += sizeof(u32) * 2; /* skip epoch and legacy_client_fscid */
4500
4501         num_fs = ceph_decode_32(&p);
4502         while (num_fs-- > 0) {
4503                 void *info_p, *info_end;
4504                 u32 info_len;
4505                 u8 info_v, info_cv;
4506                 u32 fscid, namelen;
4507
4508                 ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4509                 info_v = ceph_decode_8(&p);
4510                 info_cv = ceph_decode_8(&p);
4511                 info_len = ceph_decode_32(&p);
4512                 ceph_decode_need(&p, end, info_len, bad);
4513                 info_p = p;
4514                 info_end = p + info_len;
4515                 p = info_end;
4516
4517                 ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
4518                 fscid = ceph_decode_32(&info_p);
4519                 namelen = ceph_decode_32(&info_p);
4520                 ceph_decode_need(&info_p, info_end, namelen, bad);
4521
4522                 if (mds_namespace &&
4523                     strlen(mds_namespace) == namelen &&
4524                     !strncmp(mds_namespace, (char *)info_p, namelen)) {
4525                         mount_fscid = fscid;
4526                         break;
4527                 }
4528         }
4529
4530         ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
4531         if (mount_fscid != (u32)-1) {
4532                 fsc->client->monc.fs_cluster_id = mount_fscid;
4533                 ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
4534                                    0, true);
4535                 ceph_monc_renew_subs(&fsc->client->monc);
4536         } else {
4537                 err = -ENOENT;
4538                 goto err_out;
4539         }
4540         return;
4541
4542 bad:
4543         pr_err("error decoding fsmap\n");
4544 err_out:
4545         mutex_lock(&mdsc->mutex);
4546         mdsc->mdsmap_err = err;
4547         __wake_requests(mdsc, &mdsc->waiting_for_map);
4548         mutex_unlock(&mdsc->mutex);
4549 }
4550
4551 /*
4552  * handle mds map update.
4553  */
4554 void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4555 {
4556         u32 epoch;
4557         u32 maplen;
4558         void *p = msg->front.iov_base;
4559         void *end = p + msg->front.iov_len;
4560         struct ceph_mdsmap *newmap, *oldmap;
4561         struct ceph_fsid fsid;
4562         int err = -EINVAL;
4563
4564         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
4565         ceph_decode_copy(&p, &fsid, sizeof(fsid));
4566         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
4567                 return;
4568         epoch = ceph_decode_32(&p);
4569         maplen = ceph_decode_32(&p);
4570         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
4571
4572         /* do we need it? */
4573         mutex_lock(&mdsc->mutex);
4574         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
4575                 dout("handle_map epoch %u <= our %u\n",
4576                      epoch, mdsc->mdsmap->m_epoch);
4577                 mutex_unlock(&mdsc->mutex);
4578                 return;
4579         }
4580
4581         newmap = ceph_mdsmap_decode(&p, end);
4582         if (IS_ERR(newmap)) {
4583                 err = PTR_ERR(newmap);
4584                 goto bad_unlock;
4585         }
4586
4587         /* swap into place */
4588         if (mdsc->mdsmap) {
4589                 oldmap = mdsc->mdsmap;
4590                 mdsc->mdsmap = newmap;
4591                 check_new_map(mdsc, newmap, oldmap);
4592                 ceph_mdsmap_destroy(oldmap);
4593         } else {
4594                 mdsc->mdsmap = newmap;  /* first mds map */
4595         }
4596         mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
4597                                         MAX_LFS_FILESIZE);
4598
4599         __wake_requests(mdsc, &mdsc->waiting_for_map);
4600         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
4601                           mdsc->mdsmap->m_epoch);
4602
4603         mutex_unlock(&mdsc->mutex);
4604         schedule_delayed(mdsc);
4605         return;
4606
4607 bad_unlock:
4608         mutex_unlock(&mdsc->mutex);
4609 bad:
4610         pr_err("error decoding mdsmap %d\n", err);
4611         return;
4612 }
4613
4614 static struct ceph_connection *con_get(struct ceph_connection *con)
4615 {
4616         struct ceph_mds_session *s = con->private;
4617
4618         if (get_session(s))
4619                 return con;
4620         return NULL;
4621 }
4622
4623 static void con_put(struct ceph_connection *con)
4624 {
4625         struct ceph_mds_session *s = con->private;
4626
4627         ceph_put_mds_session(s);
4628 }
4629
4630 /*
4631  * if the client is unresponsive for long enough, the mds will kill
4632  * the session entirely.
4633  */
4634 static void peer_reset(struct ceph_connection *con)
4635 {
4636         struct ceph_mds_session *s = con->private;
4637         struct ceph_mds_client *mdsc = s->s_mdsc;
4638
4639         pr_warn("mds%d closed our session\n", s->s_mds);
4640         send_mds_reconnect(mdsc, s);
4641 }
4642
4643 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
4644 {
4645         struct ceph_mds_session *s = con->private;
4646         struct ceph_mds_client *mdsc = s->s_mdsc;
4647         int type = le16_to_cpu(msg->hdr.type);
4648
4649         mutex_lock(&mdsc->mutex);
4650         if (__verify_registered_session(mdsc, s) < 0) {
4651                 mutex_unlock(&mdsc->mutex);
4652                 goto out;
4653         }
4654         mutex_unlock(&mdsc->mutex);
4655
4656         switch (type) {
4657         case CEPH_MSG_MDS_MAP:
4658                 ceph_mdsc_handle_mdsmap(mdsc, msg);
4659                 break;
4660         case CEPH_MSG_FS_MAP_USER:
4661                 ceph_mdsc_handle_fsmap(mdsc, msg);
4662                 break;
4663         case CEPH_MSG_CLIENT_SESSION:
4664                 handle_session(s, msg);
4665                 break;
4666         case CEPH_MSG_CLIENT_REPLY:
4667                 handle_reply(s, msg);
4668                 break;
4669         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
4670                 handle_forward(mdsc, s, msg);
4671                 break;
4672         case CEPH_MSG_CLIENT_CAPS:
4673                 ceph_handle_caps(s, msg);
4674                 break;
4675         case CEPH_MSG_CLIENT_SNAP:
4676                 ceph_handle_snap(mdsc, s, msg);
4677                 break;
4678         case CEPH_MSG_CLIENT_LEASE:
4679                 handle_lease(mdsc, s, msg);
4680                 break;
4681         case CEPH_MSG_CLIENT_QUOTA:
4682                 ceph_handle_quota(mdsc, s, msg);
4683                 break;
4684
4685         default:
4686                 pr_err("received unknown message type %d %s\n", type,
4687                        ceph_msg_type_name(type));
4688         }
4689 out:
4690         ceph_msg_put(msg);
4691 }
4692
4693 /*
4694  * authentication
4695  */
4696
4697 /*
4698  * Note: returned pointer is the address of a structure that's
4699  * managed separately.  Caller must *not* attempt to free it.
4700  */
4701 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
4702                                         int *proto, int force_new)
4703 {
4704         struct ceph_mds_session *s = con->private;
4705         struct ceph_mds_client *mdsc = s->s_mdsc;
4706         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4707         struct ceph_auth_handshake *auth = &s->s_auth;
4708
4709         if (force_new && auth->authorizer) {
4710                 ceph_auth_destroy_authorizer(auth->authorizer);
4711                 auth->authorizer = NULL;
4712         }
4713         if (!auth->authorizer) {
4714                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4715                                                       auth);
4716                 if (ret)
4717                         return ERR_PTR(ret);
4718         } else {
4719                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4720                                                       auth);
4721                 if (ret)
4722                         return ERR_PTR(ret);
4723         }
4724         *proto = ac->protocol;
4725
4726         return auth;
4727 }
4728
4729 static int add_authorizer_challenge(struct ceph_connection *con,
4730                                     void *challenge_buf, int challenge_buf_len)
4731 {
4732         struct ceph_mds_session *s = con->private;
4733         struct ceph_mds_client *mdsc = s->s_mdsc;
4734         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4735
4736         return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
4737                                             challenge_buf, challenge_buf_len);
4738 }
4739
4740 static int verify_authorizer_reply(struct ceph_connection *con)
4741 {
4742         struct ceph_mds_session *s = con->private;
4743         struct ceph_mds_client *mdsc = s->s_mdsc;
4744         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4745
4746         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer);
4747 }
4748
4749 static int invalidate_authorizer(struct ceph_connection *con)
4750 {
4751         struct ceph_mds_session *s = con->private;
4752         struct ceph_mds_client *mdsc = s->s_mdsc;
4753         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4754
4755         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
4756
4757         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
4758 }
4759
4760 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
4761                                 struct ceph_msg_header *hdr, int *skip)
4762 {
4763         struct ceph_msg *msg;
4764         int type = (int) le16_to_cpu(hdr->type);
4765         int front_len = (int) le32_to_cpu(hdr->front_len);
4766
4767         if (con->in_msg)
4768                 return con->in_msg;
4769
4770         *skip = 0;
4771         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
4772         if (!msg) {
4773                 pr_err("unable to allocate msg type %d len %d\n",
4774                        type, front_len);
4775                 return NULL;
4776         }
4777
4778         return msg;
4779 }
4780
4781 static int mds_sign_message(struct ceph_msg *msg)
4782 {
4783        struct ceph_mds_session *s = msg->con->private;
4784        struct ceph_auth_handshake *auth = &s->s_auth;
4785
4786        return ceph_auth_sign_message(auth, msg);
4787 }
4788
4789 static int mds_check_message_signature(struct ceph_msg *msg)
4790 {
4791        struct ceph_mds_session *s = msg->con->private;
4792        struct ceph_auth_handshake *auth = &s->s_auth;
4793
4794        return ceph_auth_check_message_signature(auth, msg);
4795 }
4796
4797 static const struct ceph_connection_operations mds_con_ops = {
4798         .get = con_get,
4799         .put = con_put,
4800         .dispatch = dispatch,
4801         .get_authorizer = get_authorizer,
4802         .add_authorizer_challenge = add_authorizer_challenge,
4803         .verify_authorizer_reply = verify_authorizer_reply,
4804         .invalidate_authorizer = invalidate_authorizer,
4805         .peer_reset = peer_reset,
4806         .alloc_msg = mds_alloc_msg,
4807         .sign_message = mds_sign_message,
4808         .check_message_signature = mds_check_message_signature,
4809 };
4810
4811 /* eof */