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  47  * are no longer valid.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_CLOSED: return "closed";
 534         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 535         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 536         case CEPH_MDS_SESSION_REJECTED: return "rejected";
 537         default: return "???";
 538         }
 539 }
 540
 541 static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 542 {
 543         if (refcount_inc_not_zero(&s->s_ref)) {
 544                 dout("mdsc get_session %p %d -> %d\n", s,
 545                      refcount_read(&s->s_ref)-1, refcount_read(&s->s_ref));
 546                 return s;
 547         } else {
 548                 dout("mdsc get_session %p 0 -- FAIL\n", s);
 549                 return NULL;
 550         }
 551 }
 552
 553 void ceph_put_mds_session(struct ceph_mds_session *s)
 554 {
 555         dout("mdsc put_session %p %d -> %d\n", s,
 556              refcount_read(&s->s_ref), refcount_read(&s->s_ref)-1);
 557         if (refcount_dec_and_test(&s->s_ref)) {
 558                 if (s->s_auth.authorizer)
 559                         ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 560                 kfree(s);
 561         }
 562 }
 563
 564 /*
 565  * called under mdsc->mutex
 566  */
 567 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 568                                                    int mds)
 569 {
 570         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 571                 return NULL;
 572         return get_session(mdsc->sessions[mds]);
 573 }
 574
 575 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 576 {
 577         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 578                 return false;
 579         else
 580                 return true;
 581 }
 582
 583 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 584                                        struct ceph_mds_session *s)
 585 {
 586         if (s->s_mds >= mdsc->max_sessions ||
 587             mdsc->sessions[s->s_mds] != s)
 588                 return -ENOENT;
 589         return 0;
 590 }
 591
 592 /*
 593  * create+register a new session for given mds.
 594  * called under mdsc->mutex.
 595  */
 596 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 597                                                  int mds)
 598 {
 599         struct ceph_mds_session *s;
 600
 601         if (mds >= mdsc->mdsmap->m_num_mds)
 602                 return ERR_PTR(-EINVAL);
 603
 604         s = kzalloc(sizeof(*s), GFP_NOFS);
 605         if (!s)
 606                 return ERR_PTR(-ENOMEM);
 607
 608         if (mds >= mdsc->max_sessions) {
 609                 int newmax = 1 << get_count_order(mds + 1);
 610                 struct ceph_mds_session **sa;
 611
 612                 dout("%s: realloc to %d\n", __func__, newmax);
 613                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 614                 if (!sa)
 615                         goto fail_realloc;
 616                 if (mdsc->sessions) {
 617                         memcpy(sa, mdsc->sessions,
 618                                mdsc->max_sessions * sizeof(void *));
 619                         kfree(mdsc->sessions);
 620                 }
 621                 mdsc->sessions = sa;
 622                 mdsc->max_sessions = newmax;
 623         }
 624
 625         dout("%s: mds%d\n", __func__, mds);
 626         s->s_mdsc = mdsc;
 627         s->s_mds = mds;
 628         s->s_state = CEPH_MDS_SESSION_NEW;
 629         s->s_ttl = 0;
 630         s->s_seq = 0;
 631         mutex_init(&s->s_mutex);
 632
 633         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 634
 635         spin_lock_init(&s->s_gen_ttl_lock);
 636         s->s_cap_gen = 1;
 637         s->s_cap_ttl = jiffies - 1;
 638
 639         spin_lock_init(&s->s_cap_lock);
 640         s->s_renew_requested = 0;
 641         s->s_renew_seq = 0;
 642         INIT_LIST_HEAD(&s->s_caps);
 643         s->s_nr_caps = 0;
 644         refcount_set(&s->s_ref, 1);
 645         INIT_LIST_HEAD(&s->s_waiting);
 646         INIT_LIST_HEAD(&s->s_unsafe);
 647         s->s_num_cap_releases = 0;
 648         s->s_cap_reconnect = 0;
 649         s->s_cap_iterator = NULL;
 650         INIT_LIST_HEAD(&s->s_cap_releases);
 651         INIT_WORK(&s->s_cap_release_work, ceph_cap_release_work);
 652
 653         INIT_LIST_HEAD(&s->s_cap_flushing);
 654
 655         mdsc->sessions[mds] = s;
 656         atomic_inc(&mdsc->num_sessions);
 657         refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 658
 659         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 660                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 661
 662         return s;
 663
 664 fail_realloc:
 665         kfree(s);
 666         return ERR_PTR(-ENOMEM);
 667 }
 668
 669 /*
 670  * called under mdsc->mutex
 671  */
 672 static void __unregister_session(struct ceph_mds_client *mdsc,
 673                                struct ceph_mds_session *s)
 674 {
 675         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 676         BUG_ON(mdsc->sessions[s->s_mds] != s);
 677         mdsc->sessions[s->s_mds] = NULL;
 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  * called under mdsc->mutex
2527  */
2528 static int __send_request(struct ceph_mds_client *mdsc,
2529                           struct ceph_mds_session *session,
2530                           struct ceph_mds_request *req,
2531                           bool drop_cap_releases)
2532 {
2533         int err;
2534
2535         err = __prepare_send_request(mdsc, req, session->s_mds,
2536                                      drop_cap_releases);
2537         if (!err) {
2538                 ceph_msg_get(req->r_request);
2539                 ceph_con_send(&session->s_con, req->r_request);
2540         }
2541
2542         return err;
2543 }
2544
2545 /*
2546  * send request, or put it on the appropriate wait list.
2547  */
2548 static void __do_request(struct ceph_mds_client *mdsc,
2549                         struct ceph_mds_request *req)
2550 {
2551         struct ceph_mds_session *session = NULL;
2552         int mds = -1;
2553         int err = 0;
2554
2555         if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2556                 if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2557                         __unregister_request(mdsc, req);
2558                 return;
2559         }
2560
2561         if (req->r_timeout &&
2562             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2563                 dout("do_request timed out\n");
2564                 err = -EIO;
2565                 goto finish;
2566         }
2567         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2568                 dout("do_request forced umount\n");
2569                 err = -EIO;
2570                 goto finish;
2571         }
2572         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2573                 if (mdsc->mdsmap_err) {
2574                         err = mdsc->mdsmap_err;
2575                         dout("do_request mdsmap err %d\n", err);
2576                         goto finish;
2577                 }
2578                 if (mdsc->mdsmap->m_epoch == 0) {
2579                         dout("do_request no mdsmap, waiting for map\n");
2580                         list_add(&req->r_wait, &mdsc->waiting_for_map);
2581                         return;
2582                 }
2583                 if (!(mdsc->fsc->mount_options->flags &
2584                       CEPH_MOUNT_OPT_MOUNTWAIT) &&
2585                     !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2586                         err = -ENOENT;
2587                         pr_info("probably no mds server is up\n");
2588                         goto finish;
2589                 }
2590         }
2591
2592         put_request_session(req);
2593
2594         mds = __choose_mds(mdsc, req);
2595         if (mds < 0 ||
2596             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2597                 dout("do_request no mds or not active, waiting for map\n");
2598                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2599                 return;
2600         }
2601
2602         /* get, open session */
2603         session = __ceph_lookup_mds_session(mdsc, mds);
2604         if (!session) {
2605                 session = register_session(mdsc, mds);
2606                 if (IS_ERR(session)) {
2607                         err = PTR_ERR(session);
2608                         goto finish;
2609                 }
2610         }
2611         req->r_session = get_session(session);
2612
2613         dout("do_request mds%d session %p state %s\n", mds, session,
2614              ceph_session_state_name(session->s_state));
2615         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2616             session->s_state != CEPH_MDS_SESSION_HUNG) {
2617                 if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2618                         err = -EACCES;
2619                         goto out_session;
2620                 }
2621                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2622                     session->s_state == CEPH_MDS_SESSION_CLOSING)
2623                         __open_session(mdsc, session);
2624                 list_add(&req->r_wait, &session->s_waiting);
2625                 goto out_session;
2626         }
2627
2628         /* send request */
2629         req->r_resend_mds = -1;   /* forget any previous mds hint */
2630
2631         if (req->r_request_started == 0)   /* note request start time */
2632                 req->r_request_started = jiffies;
2633
2634         err = __send_request(mdsc, session, req, false);
2635
2636 out_session:
2637         ceph_put_mds_session(session);
2638 finish:
2639         if (err) {
2640                 dout("__do_request early error %d\n", err);
2641                 req->r_err = err;
2642                 complete_request(mdsc, req);
2643                 __unregister_request(mdsc, req);
2644         }
2645         return;
2646 }
2647
2648 /*
2649  * called under mdsc->mutex
2650  */
2651 static void __wake_requests(struct ceph_mds_client *mdsc,
2652                             struct list_head *head)
2653 {
2654         struct ceph_mds_request *req;
2655         LIST_HEAD(tmp_list);
2656
2657         list_splice_init(head, &tmp_list);
2658
2659         while (!list_empty(&tmp_list)) {
2660                 req = list_entry(tmp_list.next,
2661                                  struct ceph_mds_request, r_wait);
2662                 list_del_init(&req->r_wait);
2663                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2664                 __do_request(mdsc, req);
2665         }
2666 }
2667
2668 /*
2669  * Wake up threads with requests pending for @mds, so that they can
2670  * resubmit their requests to a possibly different mds.
2671  */
2672 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2673 {
2674         struct ceph_mds_request *req;
2675         struct rb_node *p = rb_first(&mdsc->request_tree);
2676
2677         dout("kick_requests mds%d\n", mds);
2678         while (p) {
2679                 req = rb_entry(p, struct ceph_mds_request, r_node);
2680                 p = rb_next(p);
2681                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2682                         continue;
2683                 if (req->r_attempts > 0)
2684                         continue; /* only new requests */
2685                 if (req->r_session &&
2686                     req->r_session->s_mds == mds) {
2687                         dout(" kicking tid %llu\n", req->r_tid);
2688                         list_del_init(&req->r_wait);
2689                         __do_request(mdsc, req);
2690                 }
2691         }
2692 }
2693
2694 int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
2695                               struct ceph_mds_request *req)
2696 {
2697         int err;
2698
2699         /* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
2700         if (req->r_inode)
2701                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2702         if (req->r_parent) {
2703                 ceph_get_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
2704                 ihold(req->r_parent);
2705         }
2706         if (req->r_old_dentry_dir)
2707                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2708                                   CEPH_CAP_PIN);
2709
2710         dout("submit_request on %p for inode %p\n", req, dir);
2711         mutex_lock(&mdsc->mutex);
2712         __register_request(mdsc, req, dir);
2713         __do_request(mdsc, req);
2714         err = req->r_err;
2715         mutex_unlock(&mdsc->mutex);
2716         return err;
2717 }
2718
2719 static int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
2720                                   struct ceph_mds_request *req)
2721 {
2722         int err;
2723
2724         /* wait */
2725         dout("do_request waiting\n");
2726         if (!req->r_timeout && req->r_wait_for_completion) {
2727                 err = req->r_wait_for_completion(mdsc, req);
2728         } else {
2729                 long timeleft = wait_for_completion_killable_timeout(
2730                                         &req->r_completion,
2731                                         ceph_timeout_jiffies(req->r_timeout));
2732                 if (timeleft > 0)
2733                         err = 0;
2734                 else if (!timeleft)
2735                         err = -EIO;  /* timed out */
2736                 else
2737                         err = timeleft;  /* killed */
2738         }
2739         dout("do_request waited, got %d\n", err);
2740         mutex_lock(&mdsc->mutex);
2741
2742         /* only abort if we didn't race with a real reply */
2743         if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2744                 err = le32_to_cpu(req->r_reply_info.head->result);
2745         } else if (err < 0) {
2746                 dout("aborted request %lld with %d\n", req->r_tid, err);
2747
2748                 /*
2749                  * ensure we aren't running concurrently with
2750                  * ceph_fill_trace or ceph_readdir_prepopulate, which
2751                  * rely on locks (dir mutex) held by our caller.
2752                  */
2753                 mutex_lock(&req->r_fill_mutex);
2754                 req->r_err = err;
2755                 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
2756                 mutex_unlock(&req->r_fill_mutex);
2757
2758                 if (req->r_parent &&
2759                     (req->r_op & CEPH_MDS_OP_WRITE))
2760                         ceph_invalidate_dir_request(req);
2761         } else {
2762                 err = req->r_err;
2763         }
2764
2765         mutex_unlock(&mdsc->mutex);
2766         return err;
2767 }
2768
2769 /*
2770  * Synchrously perform an mds request.  Take care of all of the
2771  * session setup, forwarding, retry details.
2772  */
2773 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2774                          struct inode *dir,
2775                          struct ceph_mds_request *req)
2776 {
2777         int err;
2778
2779         dout("do_request on %p\n", req);
2780
2781         /* issue */
2782         err = ceph_mdsc_submit_request(mdsc, dir, req);
2783         if (!err)
2784                 err = ceph_mdsc_wait_request(mdsc, req);
2785         dout("do_request %p done, result %d\n", req, err);
2786         return err;
2787 }
2788
2789 /*
2790  * Invalidate dir's completeness, dentry lease state on an aborted MDS
2791  * namespace request.
2792  */
2793 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2794 {
2795         struct inode *dir = req->r_parent;
2796         struct inode *old_dir = req->r_old_dentry_dir;
2797
2798         dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
2799
2800         ceph_dir_clear_complete(dir);
2801         if (old_dir)
2802                 ceph_dir_clear_complete(old_dir);
2803         if (req->r_dentry)
2804                 ceph_invalidate_dentry_lease(req->r_dentry);
2805         if (req->r_old_dentry)
2806                 ceph_invalidate_dentry_lease(req->r_old_dentry);
2807 }
2808
2809 /*
2810  * Handle mds reply.
2811  *
2812  * We take the session mutex and parse and process the reply immediately.
2813  * This preserves the logical ordering of replies, capabilities, etc., sent
2814  * by the MDS as they are applied to our local cache.
2815  */
2816 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2817 {
2818         struct ceph_mds_client *mdsc = session->s_mdsc;
2819         struct ceph_mds_request *req;
2820         struct ceph_mds_reply_head *head = msg->front.iov_base;
2821         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2822         struct ceph_snap_realm *realm;
2823         u64 tid;
2824         int err, result;
2825         int mds = session->s_mds;
2826
2827         if (msg->front.iov_len < sizeof(*head)) {
2828                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2829                 ceph_msg_dump(msg);
2830                 return;
2831         }
2832
2833         /* get request, session */
2834         tid = le64_to_cpu(msg->hdr.tid);
2835         mutex_lock(&mdsc->mutex);
2836         req = lookup_get_request(mdsc, tid);
2837         if (!req) {
2838                 dout("handle_reply on unknown tid %llu\n", tid);
2839                 mutex_unlock(&mdsc->mutex);
2840                 return;
2841         }
2842         dout("handle_reply %p\n", req);
2843
2844         /* correct session? */
2845         if (req->r_session != session) {
2846                 pr_err("mdsc_handle_reply got %llu on session mds%d"
2847                        " not mds%d\n", tid, session->s_mds,
2848                        req->r_session ? req->r_session->s_mds : -1);
2849                 mutex_unlock(&mdsc->mutex);
2850                 goto out;
2851         }
2852
2853         /* dup? */
2854         if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
2855             (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
2856                 pr_warn("got a dup %s reply on %llu from mds%d\n",
2857                            head->safe ? "safe" : "unsafe", tid, mds);
2858                 mutex_unlock(&mdsc->mutex);
2859                 goto out;
2860         }
2861         if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
2862                 pr_warn("got unsafe after safe on %llu from mds%d\n",
2863                            tid, mds);
2864                 mutex_unlock(&mdsc->mutex);
2865                 goto out;
2866         }
2867
2868         result = le32_to_cpu(head->result);
2869
2870         /*
2871          * Handle an ESTALE
2872          * if we're not talking to the authority, send to them
2873          * if the authority has changed while we weren't looking,
2874          * send to new authority
2875          * Otherwise we just have to return an ESTALE
2876          */
2877         if (result == -ESTALE) {
2878                 dout("got ESTALE on request %llu\n", req->r_tid);
2879                 req->r_resend_mds = -1;
2880                 if (req->r_direct_mode != USE_AUTH_MDS) {
2881                         dout("not using auth, setting for that now\n");
2882                         req->r_direct_mode = USE_AUTH_MDS;
2883                         __do_request(mdsc, req);
2884                         mutex_unlock(&mdsc->mutex);
2885                         goto out;
2886                 } else  {
2887                         int mds = __choose_mds(mdsc, req);
2888                         if (mds >= 0 && mds != req->r_session->s_mds) {
2889                                 dout("but auth changed, so resending\n");
2890                                 __do_request(mdsc, req);
2891                                 mutex_unlock(&mdsc->mutex);
2892                                 goto out;
2893                         }
2894                 }
2895                 dout("have to return ESTALE on request %llu\n", req->r_tid);
2896         }
2897
2898
2899         if (head->safe) {
2900                 set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
2901                 __unregister_request(mdsc, req);
2902
2903                 /* last request during umount? */
2904                 if (mdsc->stopping && !__get_oldest_req(mdsc))
2905                         complete_all(&mdsc->safe_umount_waiters);
2906
2907                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2908                         /*
2909                          * We already handled the unsafe response, now do the
2910                          * cleanup.  No need to examine the response; the MDS
2911                          * doesn't include any result info in the safe
2912                          * response.  And even if it did, there is nothing
2913                          * useful we could do with a revised return value.
2914                          */
2915                         dout("got safe reply %llu, mds%d\n", tid, mds);
2916
2917                         mutex_unlock(&mdsc->mutex);
2918                         goto out;
2919                 }
2920         } else {
2921                 set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
2922                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2923                 if (req->r_unsafe_dir) {
2924                         struct ceph_inode_info *ci =
2925                                         ceph_inode(req->r_unsafe_dir);
2926                         spin_lock(&ci->i_unsafe_lock);
2927                         list_add_tail(&req->r_unsafe_dir_item,
2928                                       &ci->i_unsafe_dirops);
2929                         spin_unlock(&ci->i_unsafe_lock);
2930                 }
2931         }
2932
2933         dout("handle_reply tid %lld result %d\n", tid, result);
2934         rinfo = &req->r_reply_info;
2935         if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
2936                 err = parse_reply_info(msg, rinfo, (u64)-1);
2937         else
2938                 err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2939         mutex_unlock(&mdsc->mutex);
2940
2941         mutex_lock(&session->s_mutex);
2942         if (err < 0) {
2943                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2944                 ceph_msg_dump(msg);
2945                 goto out_err;
2946         }
2947
2948         /* snap trace */
2949         realm = NULL;
2950         if (rinfo->snapblob_len) {
2951                 down_write(&mdsc->snap_rwsem);
2952                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
2953                                 rinfo->snapblob + rinfo->snapblob_len,
2954                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
2955                                 &realm);
2956                 downgrade_write(&mdsc->snap_rwsem);
2957         } else {
2958                 down_read(&mdsc->snap_rwsem);
2959         }
2960
2961         /* insert trace into our cache */
2962         mutex_lock(&req->r_fill_mutex);
2963         current->journal_info = req;
2964         err = ceph_fill_trace(mdsc->fsc->sb, req);
2965         if (err == 0) {
2966                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2967                                     req->r_op == CEPH_MDS_OP_LSSNAP))
2968                         ceph_readdir_prepopulate(req, req->r_session);
2969         }
2970         current->journal_info = NULL;
2971         mutex_unlock(&req->r_fill_mutex);
2972
2973         up_read(&mdsc->snap_rwsem);
2974         if (realm)
2975                 ceph_put_snap_realm(mdsc, realm);
2976
2977         if (err == 0) {
2978                 if (req->r_target_inode &&
2979                     test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2980                         struct ceph_inode_info *ci =
2981                                 ceph_inode(req->r_target_inode);
2982                         spin_lock(&ci->i_unsafe_lock);
2983                         list_add_tail(&req->r_unsafe_target_item,
2984                                       &ci->i_unsafe_iops);
2985                         spin_unlock(&ci->i_unsafe_lock);
2986                 }
2987
2988                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2989         }
2990 out_err:
2991         mutex_lock(&mdsc->mutex);
2992         if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
2993                 if (err) {
2994                         req->r_err = err;
2995                 } else {
2996                         req->r_reply =  ceph_msg_get(msg);
2997                         set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
2998                 }
2999         } else {
3000                 dout("reply arrived after request %lld was aborted\n", tid);
3001         }
3002         mutex_unlock(&mdsc->mutex);
3003
3004         mutex_unlock(&session->s_mutex);
3005
3006         /* kick calling process */
3007         complete_request(mdsc, req);
3008 out:
3009         ceph_mdsc_put_request(req);
3010         return;
3011 }
3012
3013
3014
3015 /*
3016  * handle mds notification that our request has been forwarded.
3017  */
3018 static void handle_forward(struct ceph_mds_client *mdsc,
3019                            struct ceph_mds_session *session,
3020                            struct ceph_msg *msg)
3021 {
3022         struct ceph_mds_request *req;
3023         u64 tid = le64_to_cpu(msg->hdr.tid);
3024         u32 next_mds;
3025         u32 fwd_seq;
3026         int err = -EINVAL;
3027         void *p = msg->front.iov_base;
3028         void *end = p + msg->front.iov_len;
3029
3030         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
3031         next_mds = ceph_decode_32(&p);
3032         fwd_seq = ceph_decode_32(&p);
3033
3034         mutex_lock(&mdsc->mutex);
3035         req = lookup_get_request(mdsc, tid);
3036         if (!req) {
3037                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
3038                 goto out;  /* dup reply? */
3039         }
3040
3041         if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3042                 dout("forward tid %llu aborted, unregistering\n", tid);
3043                 __unregister_request(mdsc, req);
3044         } else if (fwd_seq <= req->r_num_fwd) {
3045                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
3046                      tid, next_mds, req->r_num_fwd, fwd_seq);
3047         } else {
3048                 /* resend. forward race not possible; mds would drop */
3049                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
3050                 BUG_ON(req->r_err);
3051                 BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
3052                 req->r_attempts = 0;
3053                 req->r_num_fwd = fwd_seq;
3054                 req->r_resend_mds = next_mds;
3055                 put_request_session(req);
3056                 __do_request(mdsc, req);
3057         }
3058         ceph_mdsc_put_request(req);
3059 out:
3060         mutex_unlock(&mdsc->mutex);
3061         return;
3062
3063 bad:
3064         pr_err("mdsc_handle_forward decode error err=%d\n", err);
3065 }
3066
3067 static int __decode_session_metadata(void **p, void *end,
3068                                      bool *blacklisted)
3069 {
3070         /* map<string,string> */
3071         u32 n;
3072         bool err_str;
3073         ceph_decode_32_safe(p, end, n, bad);
3074         while (n-- > 0) {
3075                 u32 len;
3076                 ceph_decode_32_safe(p, end, len, bad);
3077                 ceph_decode_need(p, end, len, bad);
3078                 err_str = !strncmp(*p, "error_string", len);
3079                 *p += len;
3080                 ceph_decode_32_safe(p, end, len, bad);
3081                 ceph_decode_need(p, end, len, bad);
3082                 if (err_str && strnstr(*p, "blacklisted", len))
3083                         *blacklisted = true;
3084                 *p += len;
3085         }
3086         return 0;
3087 bad:
3088         return -1;
3089 }
3090
3091 /*
3092  * handle a mds session control message
3093  */
3094 static void handle_session(struct ceph_mds_session *session,
3095                            struct ceph_msg *msg)
3096 {
3097         struct ceph_mds_client *mdsc = session->s_mdsc;
3098         int mds = session->s_mds;
3099         int msg_version = le16_to_cpu(msg->hdr.version);
3100         void *p = msg->front.iov_base;
3101         void *end = p + msg->front.iov_len;
3102         struct ceph_mds_session_head *h;
3103         u32 op;
3104         u64 seq;
3105         unsigned long features = 0;
3106         int wake = 0;
3107         bool blacklisted = false;
3108
3109         /* decode */
3110         ceph_decode_need(&p, end, sizeof(*h), bad);
3111         h = p;
3112         p += sizeof(*h);
3113
3114         op = le32_to_cpu(h->op);
3115         seq = le64_to_cpu(h->seq);
3116
3117         if (msg_version >= 3) {
3118                 u32 len;
3119                 /* version >= 2, metadata */
3120                 if (__decode_session_metadata(&p, end, &blacklisted) < 0)
3121                         goto bad;
3122                 /* version >= 3, feature bits */
3123                 ceph_decode_32_safe(&p, end, len, bad);
3124                 ceph_decode_need(&p, end, len, bad);
3125                 memcpy(&features, p, min_t(size_t, len, sizeof(features)));
3126                 p += len;
3127         }
3128
3129         mutex_lock(&mdsc->mutex);
3130         if (op == CEPH_SESSION_CLOSE) {
3131                 get_session(session);
3132                 __unregister_session(mdsc, session);
3133         }
3134         /* FIXME: this ttl calculation is generous */
3135         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
3136         mutex_unlock(&mdsc->mutex);
3137
3138         mutex_lock(&session->s_mutex);
3139
3140         dout("handle_session mds%d %s %p state %s seq %llu\n",
3141              mds, ceph_session_op_name(op), session,
3142              ceph_session_state_name(session->s_state), seq);
3143
3144         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
3145                 session->s_state = CEPH_MDS_SESSION_OPEN;
3146                 pr_info("mds%d came back\n", session->s_mds);
3147         }
3148
3149         switch (op) {
3150         case CEPH_SESSION_OPEN:
3151                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3152                         pr_info("mds%d reconnect success\n", session->s_mds);
3153                 session->s_state = CEPH_MDS_SESSION_OPEN;
3154                 session->s_features = features;
3155                 renewed_caps(mdsc, session, 0);
3156                 wake = 1;
3157                 if (mdsc->stopping)
3158                         __close_session(mdsc, session);
3159                 break;
3160
3161         case CEPH_SESSION_RENEWCAPS:
3162                 if (session->s_renew_seq == seq)
3163                         renewed_caps(mdsc, session, 1);
3164                 break;
3165
3166         case CEPH_SESSION_CLOSE:
3167                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3168                         pr_info("mds%d reconnect denied\n", session->s_mds);
3169                 session->s_state = CEPH_MDS_SESSION_CLOSED;
3170                 cleanup_session_requests(mdsc, session);
3171                 remove_session_caps(session);
3172                 wake = 2; /* for good measure */
3173                 wake_up_all(&mdsc->session_close_wq);
3174                 break;
3175
3176         case CEPH_SESSION_STALE:
3177                 pr_info("mds%d caps went stale, renewing\n",
3178                         session->s_mds);
3179                 spin_lock(&session->s_gen_ttl_lock);
3180                 session->s_cap_gen++;
3181                 session->s_cap_ttl = jiffies - 1;
3182                 spin_unlock(&session->s_gen_ttl_lock);
3183                 send_renew_caps(mdsc, session);
3184                 break;
3185
3186         case CEPH_SESSION_RECALL_STATE:
3187                 ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
3188                 break;
3189
3190         case CEPH_SESSION_FLUSHMSG:
3191                 send_flushmsg_ack(mdsc, session, seq);
3192                 break;
3193
3194         case CEPH_SESSION_FORCE_RO:
3195                 dout("force_session_readonly %p\n", session);
3196                 spin_lock(&session->s_cap_lock);
3197                 session->s_readonly = true;
3198                 spin_unlock(&session->s_cap_lock);
3199                 wake_up_session_caps(session, FORCE_RO);
3200                 break;
3201
3202         case CEPH_SESSION_REJECT:
3203                 WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
3204                 pr_info("mds%d rejected session\n", session->s_mds);
3205                 session->s_state = CEPH_MDS_SESSION_REJECTED;
3206                 cleanup_session_requests(mdsc, session);
3207                 remove_session_caps(session);
3208                 if (blacklisted)
3209                         mdsc->fsc->blacklisted = true;
3210                 wake = 2; /* for good measure */
3211                 break;
3212
3213         default:
3214                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
3215                 WARN_ON(1);
3216         }
3217
3218         mutex_unlock(&session->s_mutex);
3219         if (wake) {
3220                 mutex_lock(&mdsc->mutex);
3221                 __wake_requests(mdsc, &session->s_waiting);
3222                 if (wake == 2)
3223                         kick_requests(mdsc, mds);
3224                 mutex_unlock(&mdsc->mutex);
3225         }
3226         if (op == CEPH_SESSION_CLOSE)
3227                 ceph_put_mds_session(session);
3228         return;
3229
3230 bad:
3231         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
3232                (int)msg->front.iov_len);
3233         ceph_msg_dump(msg);
3234         return;
3235 }
3236
3237 /*
3238  * called under session->mutex.
3239  */
3240 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
3241                                    struct ceph_mds_session *session)
3242 {
3243         struct ceph_mds_request *req, *nreq;
3244         struct rb_node *p;
3245
3246         dout("replay_unsafe_requests mds%d\n", session->s_mds);
3247
3248         mutex_lock(&mdsc->mutex);
3249         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item)
3250                 __send_request(mdsc, session, req, true);
3251
3252         /*
3253          * also re-send old requests when MDS enters reconnect stage. So that MDS
3254          * can process completed request in clientreplay stage.
3255          */
3256         p = rb_first(&mdsc->request_tree);
3257         while (p) {
3258                 req = rb_entry(p, struct ceph_mds_request, r_node);
3259                 p = rb_next(p);
3260                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3261                         continue;
3262                 if (req->r_attempts == 0)
3263                         continue; /* only old requests */
3264                 if (req->r_session &&
3265                     req->r_session->s_mds == session->s_mds)
3266                         __send_request(mdsc, session, req, true);
3267         }
3268         mutex_unlock(&mdsc->mutex);
3269 }
3270
3271 static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
3272 {
3273         struct ceph_msg *reply;
3274         struct ceph_pagelist *_pagelist;
3275         struct page *page;
3276         __le32 *addr;
3277         int err = -ENOMEM;
3278
3279         if (!recon_state->allow_multi)
3280                 return -ENOSPC;
3281
3282         /* can't handle message that contains both caps and realm */
3283         BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3284
3285         /* pre-allocate new pagelist */
3286         _pagelist = ceph_pagelist_alloc(GFP_NOFS);
3287         if (!_pagelist)
3288                 return -ENOMEM;
3289
3290         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3291         if (!reply)
3292                 goto fail_msg;
3293
3294         /* placeholder for nr_caps */
3295         err = ceph_pagelist_encode_32(_pagelist, 0);
3296         if (err < 0)
3297                 goto fail;
3298
3299         if (recon_state->nr_caps) {
3300                 /* currently encoding caps */
3301                 err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3302                 if (err)
3303                         goto fail;
3304         } else {
3305                 /* placeholder for nr_realms (currently encoding relams) */
3306                 err = ceph_pagelist_encode_32(_pagelist, 0);
3307                 if (err < 0)
3308                         goto fail;
3309         }
3310
3311         err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3312         if (err)
3313                 goto fail;
3314
3315         page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3316         addr = kmap_atomic(page);
3317         if (recon_state->nr_caps) {
3318                 /* currently encoding caps */
3319                 *addr = cpu_to_le32(recon_state->nr_caps);
3320         } else {
3321                 /* currently encoding relams */
3322                 *(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3323         }
3324         kunmap_atomic(addr);
3325
3326         reply->hdr.version = cpu_to_le16(5);
3327         reply->hdr.compat_version = cpu_to_le16(4);
3328
3329         reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3330         ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3331
3332         ceph_con_send(&recon_state->session->s_con, reply);
3333         ceph_pagelist_release(recon_state->pagelist);
3334
3335         recon_state->pagelist = _pagelist;
3336         recon_state->nr_caps = 0;
3337         recon_state->nr_realms = 0;
3338         recon_state->msg_version = 5;
3339         return 0;
3340 fail:
3341         ceph_msg_put(reply);
3342 fail_msg:
3343         ceph_pagelist_release(_pagelist);
3344         return err;
3345 }
3346
3347 /*
3348  * Encode information about a cap for a reconnect with the MDS.
3349  */
3350 static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
3351                           void *arg)
3352 {
3353         union {
3354                 struct ceph_mds_cap_reconnect v2;
3355                 struct ceph_mds_cap_reconnect_v1 v1;
3356         } rec;
3357         struct ceph_inode_info *ci = cap->ci;
3358         struct ceph_reconnect_state *recon_state = arg;
3359         struct ceph_pagelist *pagelist = recon_state->pagelist;
3360         int err;
3361         u64 snap_follows;
3362
3363         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3364              inode, ceph_vinop(inode), cap, cap->cap_id,
3365              ceph_cap_string(cap->issued));
3366
3367         spin_lock(&ci->i_ceph_lock);
3368         cap->seq = 0;        /* reset cap seq */
3369         cap->issue_seq = 0;  /* and issue_seq */
3370         cap->mseq = 0;       /* and migrate_seq */
3371         cap->cap_gen = cap->session->s_cap_gen;
3372
3373         if (recon_state->msg_version >= 2) {
3374                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3375                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3376                 rec.v2.issued = cpu_to_le32(cap->issued);
3377                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3378                 rec.v2.pathbase = 0;
3379                 rec.v2.flock_len = (__force __le32)
3380                         ((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3381         } else {
3382                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3383                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3384                 rec.v1.issued = cpu_to_le32(cap->issued);
3385                 rec.v1.size = cpu_to_le64(inode->i_size);
3386                 ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3387                 ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3388                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3389                 rec.v1.pathbase = 0;
3390         }
3391
3392         if (list_empty(&ci->i_cap_snaps)) {
3393                 snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3394         } else {
3395                 struct ceph_cap_snap *capsnap =
3396                         list_first_entry(&ci->i_cap_snaps,
3397                                          struct ceph_cap_snap, ci_item);
3398                 snap_follows = capsnap->follows;
3399         }
3400         spin_unlock(&ci->i_ceph_lock);
3401
3402         if (recon_state->msg_version >= 2) {
3403                 int num_fcntl_locks, num_flock_locks;
3404                 struct ceph_filelock *flocks = NULL;
3405                 size_t struct_len, total_len = sizeof(u64);
3406                 u8 struct_v = 0;
3407
3408 encode_again:
3409                 if (rec.v2.flock_len) {
3410                         ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
3411                 } else {
3412                         num_fcntl_locks = 0;
3413                         num_flock_locks = 0;
3414                 }
3415                 if (num_fcntl_locks + num_flock_locks > 0) {
3416                         flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
3417                                                sizeof(struct ceph_filelock),
3418                                                GFP_NOFS);
3419                         if (!flocks) {
3420                                 err = -ENOMEM;
3421                                 goto out_err;
3422                         }
3423                         err = ceph_encode_locks_to_buffer(inode, flocks,
3424                                                           num_fcntl_locks,
3425                                                           num_flock_locks);
3426                         if (err) {
3427                                 kfree(flocks);
3428                                 flocks = NULL;
3429                                 if (err == -ENOSPC)
3430                                         goto encode_again;
3431                                 goto out_err;
3432                         }
3433                 } else {
3434                         kfree(flocks);
3435                         flocks = NULL;
3436                 }
3437
3438                 if (recon_state->msg_version >= 3) {
3439                         /* version, compat_version and struct_len */
3440                         total_len += 2 * sizeof(u8) + sizeof(u32);
3441                         struct_v = 2;
3442                 }
3443                 /*
3444                  * number of encoded locks is stable, so copy to pagelist
3445                  */
3446                 struct_len = 2 * sizeof(u32) +
3447                             (num_fcntl_locks + num_flock_locks) *
3448                             sizeof(struct ceph_filelock);
3449                 rec.v2.flock_len = cpu_to_le32(struct_len);
3450
3451                 struct_len += sizeof(u32) + sizeof(rec.v2);
3452
3453                 if (struct_v >= 2)
3454                         struct_len += sizeof(u64); /* snap_follows */
3455
3456                 total_len += struct_len;
3457
3458                 if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
3459                         err = send_reconnect_partial(recon_state);
3460                         if (err)
3461                                 goto out_freeflocks;
3462                         pagelist = recon_state->pagelist;
3463                 }
3464
3465                 err = ceph_pagelist_reserve(pagelist, total_len);
3466                 if (err)
3467                         goto out_freeflocks;
3468
3469                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3470                 if (recon_state->msg_version >= 3) {
3471                         ceph_pagelist_encode_8(pagelist, struct_v);
3472                         ceph_pagelist_encode_8(pagelist, 1);
3473                         ceph_pagelist_encode_32(pagelist, struct_len);
3474                 }
3475                 ceph_pagelist_encode_string(pagelist, NULL, 0);
3476                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
3477                 ceph_locks_to_pagelist(flocks, pagelist,
3478                                        num_fcntl_locks, num_flock_locks);
3479                 if (struct_v >= 2)
3480                         ceph_pagelist_encode_64(pagelist, snap_follows);
3481 out_freeflocks:
3482                 kfree(flocks);
3483         } else {
3484                 u64 pathbase = 0;
3485                 int pathlen = 0;
3486                 char *path = NULL;
3487                 struct dentry *dentry;
3488
3489                 dentry = d_find_alias(inode);
3490                 if (dentry) {
3491                         path = ceph_mdsc_build_path(dentry,
3492                                                 &pathlen, &pathbase, 0);
3493                         dput(dentry);
3494                         if (IS_ERR(path)) {
3495                                 err = PTR_ERR(path);
3496                                 goto out_err;
3497                         }
3498                         rec.v1.pathbase = cpu_to_le64(pathbase);
3499                 }
3500
3501                 err = ceph_pagelist_reserve(pagelist,
3502                                             sizeof(u64) + sizeof(u32) +
3503                                             pathlen + sizeof(rec.v1));
3504                 if (err) {
3505                         goto out_freepath;
3506                 }
3507
3508                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3509                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3510                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
3511 out_freepath:
3512                 ceph_mdsc_free_path(path, pathlen);
3513         }
3514
3515 out_err:
3516         if (err >= 0)
3517                 recon_state->nr_caps++;
3518         return err;
3519 }
3520
3521 static int encode_snap_realms(struct ceph_mds_client *mdsc,
3522                               struct ceph_reconnect_state *recon_state)
3523 {
3524         struct rb_node *p;
3525         struct ceph_pagelist *pagelist = recon_state->pagelist;
3526         int err = 0;
3527
3528         if (recon_state->msg_version >= 4) {
3529                 err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
3530                 if (err < 0)
3531                         goto fail;
3532         }
3533
3534         /*
3535          * snaprealms.  we provide mds with the ino, seq (version), and
3536          * parent for all of our realms.  If the mds has any newer info,
3537          * it will tell us.
3538          */
3539         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3540                 struct ceph_snap_realm *realm =
3541                        rb_entry(p, struct ceph_snap_realm, node);
3542                 struct ceph_mds_snaprealm_reconnect sr_rec;
3543
3544                 if (recon_state->msg_version >= 4) {
3545                         size_t need = sizeof(u8) * 2 + sizeof(u32) +
3546                                       sizeof(sr_rec);
3547
3548                         if (pagelist->length + need > RECONNECT_MAX_SIZE) {
3549                                 err = send_reconnect_partial(recon_state);
3550                                 if (err)
3551                                         goto fail;
3552                                 pagelist = recon_state->pagelist;
3553                         }
3554
3555                         err = ceph_pagelist_reserve(pagelist, need);
3556                         if (err)
3557                                 goto fail;
3558
3559                         ceph_pagelist_encode_8(pagelist, 1);
3560                         ceph_pagelist_encode_8(pagelist, 1);
3561                         ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
3562                 }
3563
3564                 dout(" adding snap realm %llx seq %lld parent %llx\n",
3565                      realm->ino, realm->seq, realm->parent_ino);
3566                 sr_rec.ino = cpu_to_le64(realm->ino);
3567                 sr_rec.seq = cpu_to_le64(realm->seq);
3568                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
3569
3570                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3571                 if (err)
3572                         goto fail;
3573
3574                 recon_state->nr_realms++;
3575         }
3576 fail:
3577         return err;
3578 }
3579
3580
3581 /*
3582  * If an MDS fails and recovers, clients need to reconnect in order to
3583  * reestablish shared state.  This includes all caps issued through
3584  * this session _and_ the snap_realm hierarchy.  Because it's not
3585  * clear which snap realms the mds cares about, we send everything we
3586  * know about.. that ensures we'll then get any new info the
3587  * recovering MDS might have.
3588  *
3589  * This is a relatively heavyweight operation, but it's rare.
3590  *
3591  * called with mdsc->mutex held.
3592  */
3593 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
3594                                struct ceph_mds_session *session)
3595 {
3596         struct ceph_msg *reply;
3597         int mds = session->s_mds;
3598         int err = -ENOMEM;
3599         struct ceph_reconnect_state recon_state = {
3600                 .session = session,
3601         };
3602         LIST_HEAD(dispose);
3603
3604         pr_info("mds%d reconnect start\n", mds);
3605
3606         recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
3607         if (!recon_state.pagelist)
3608                 goto fail_nopagelist;
3609
3610         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3611         if (!reply)
3612                 goto fail_nomsg;
3613
3614         mutex_lock(&session->s_mutex);
3615         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
3616         session->s_seq = 0;
3617
3618         dout("session %p state %s\n", session,
3619              ceph_session_state_name(session->s_state));
3620
3621         spin_lock(&session->s_gen_ttl_lock);
3622         session->s_cap_gen++;
3623         spin_unlock(&session->s_gen_ttl_lock);
3624
3625         spin_lock(&session->s_cap_lock);
3626         /* don't know if session is readonly */
3627         session->s_readonly = 0;
3628         /*
3629          * notify __ceph_remove_cap() that we are composing cap reconnect.
3630          * If a cap get released before being added to the cap reconnect,
3631          * __ceph_remove_cap() should skip queuing cap release.
3632          */
3633         session->s_cap_reconnect = 1;
3634         /* drop old cap expires; we're about to reestablish that state */
3635         detach_cap_releases(session, &dispose);
3636         spin_unlock(&session->s_cap_lock);
3637         dispose_cap_releases(mdsc, &dispose);
3638
3639         /* trim unused caps to reduce MDS's cache rejoin time */
3640         if (mdsc->fsc->sb->s_root)
3641                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
3642
3643         ceph_con_close(&session->s_con);
3644         ceph_con_open(&session->s_con,
3645                       CEPH_ENTITY_TYPE_MDS, mds,
3646                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
3647
3648         /* replay unsafe requests */
3649         replay_unsafe_requests(mdsc, session);
3650
3651         ceph_early_kick_flushing_caps(mdsc, session);
3652
3653         down_read(&mdsc->snap_rwsem);
3654
3655         /* placeholder for nr_caps */
3656         err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
3657         if (err)
3658                 goto fail;
3659
3660         if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
3661                 recon_state.msg_version = 3;
3662                 recon_state.allow_multi = true;
3663         } else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
3664                 recon_state.msg_version = 3;
3665         } else {
3666                 recon_state.msg_version = 2;
3667         }
3668         /* trsaverse this session's caps */
3669         err = ceph_iterate_session_caps(session, encode_caps_cb, &recon_state);
3670
3671         spin_lock(&session->s_cap_lock);
3672         session->s_cap_reconnect = 0;
3673         spin_unlock(&session->s_cap_lock);
3674
3675         if (err < 0)
3676                 goto fail;
3677
3678         /* check if all realms can be encoded into current message */
3679         if (mdsc->num_snap_realms) {
3680                 size_t total_len =
3681                         recon_state.pagelist->length +
3682                         mdsc->num_snap_realms *
3683                         sizeof(struct ceph_mds_snaprealm_reconnect);
3684                 if (recon_state.msg_version >= 4) {
3685                         /* number of realms */
3686                         total_len += sizeof(u32);
3687                         /* version, compat_version and struct_len */
3688                         total_len += mdsc->num_snap_realms *
3689                                      (2 * sizeof(u8) + sizeof(u32));
3690                 }
3691                 if (total_len > RECONNECT_MAX_SIZE) {
3692                         if (!recon_state.allow_multi) {
3693                                 err = -ENOSPC;
3694                                 goto fail;
3695                         }
3696                         if (recon_state.nr_caps) {
3697                                 err = send_reconnect_partial(&recon_state);
3698                                 if (err)
3699                                         goto fail;
3700                         }
3701                         recon_state.msg_version = 5;
3702                 }
3703         }
3704
3705         err = encode_snap_realms(mdsc, &recon_state);
3706         if (err < 0)
3707                 goto fail;
3708
3709         if (recon_state.msg_version >= 5) {
3710                 err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
3711                 if (err < 0)
3712                         goto fail;
3713         }
3714
3715         if (recon_state.nr_caps || recon_state.nr_realms) {
3716                 struct page *page =
3717                         list_first_entry(&recon_state.pagelist->head,
3718                                         struct page, lru);
3719                 __le32 *addr = kmap_atomic(page);
3720                 if (recon_state.nr_caps) {
3721                         WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
3722                         *addr = cpu_to_le32(recon_state.nr_caps);
3723                 } else if (recon_state.msg_version >= 4) {
3724                         *(addr + 1) = cpu_to_le32(recon_state.nr_realms);
3725                 }
3726                 kunmap_atomic(addr);
3727         }
3728
3729         reply->hdr.version = cpu_to_le16(recon_state.msg_version);
3730         if (recon_state.msg_version >= 4)
3731                 reply->hdr.compat_version = cpu_to_le16(4);
3732
3733         reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
3734         ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
3735
3736         ceph_con_send(&session->s_con, reply);
3737
3738         mutex_unlock(&session->s_mutex);
3739
3740         mutex_lock(&mdsc->mutex);
3741         __wake_requests(mdsc, &session->s_waiting);
3742         mutex_unlock(&mdsc->mutex);
3743
3744         up_read(&mdsc->snap_rwsem);
3745         ceph_pagelist_release(recon_state.pagelist);
3746         return;
3747
3748 fail:
3749         ceph_msg_put(reply);
3750         up_read(&mdsc->snap_rwsem);
3751         mutex_unlock(&session->s_mutex);
3752 fail_nomsg:
3753         ceph_pagelist_release(recon_state.pagelist);
3754 fail_nopagelist:
3755         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
3756         return;
3757 }
3758
3759
3760 /*
3761  * compare old and new mdsmaps, kicking requests
3762  * and closing out old connections as necessary
3763  *
3764  * called under mdsc->mutex.
3765  */
3766 static void check_new_map(struct ceph_mds_client *mdsc,
3767                           struct ceph_mdsmap *newmap,
3768                           struct ceph_mdsmap *oldmap)
3769 {
3770         int i;
3771         int oldstate, newstate;
3772         struct ceph_mds_session *s;
3773
3774         dout("check_new_map new %u old %u\n",
3775              newmap->m_epoch, oldmap->m_epoch);
3776
3777         for (i = 0; i < oldmap->m_num_mds && i < mdsc->max_sessions; i++) {
3778                 if (!mdsc->sessions[i])
3779                         continue;
3780                 s = mdsc->sessions[i];
3781                 oldstate = ceph_mdsmap_get_state(oldmap, i);
3782                 newstate = ceph_mdsmap_get_state(newmap, i);
3783
3784                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
3785                      i, ceph_mds_state_name(oldstate),
3786                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
3787                      ceph_mds_state_name(newstate),
3788                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
3789                      ceph_session_state_name(s->s_state));
3790
3791                 if (i >= newmap->m_num_mds) {
3792                         /* force close session for stopped mds */
3793                         get_session(s);
3794                         __unregister_session(mdsc, s);
3795                         __wake_requests(mdsc, &s->s_waiting);
3796                         mutex_unlock(&mdsc->mutex);
3797
3798                         mutex_lock(&s->s_mutex);
3799                         cleanup_session_requests(mdsc, s);
3800                         remove_session_caps(s);
3801                         mutex_unlock(&s->s_mutex);
3802
3803                         ceph_put_mds_session(s);
3804
3805                         mutex_lock(&mdsc->mutex);
3806                         kick_requests(mdsc, i);
3807                         continue;
3808                 }
3809
3810                 if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
3811                            ceph_mdsmap_get_addr(newmap, i),
3812                            sizeof(struct ceph_entity_addr))) {
3813                         /* just close it */
3814                         mutex_unlock(&mdsc->mutex);
3815                         mutex_lock(&s->s_mutex);
3816                         mutex_lock(&mdsc->mutex);
3817                         ceph_con_close(&s->s_con);
3818                         mutex_unlock(&s->s_mutex);
3819                         s->s_state = CEPH_MDS_SESSION_RESTARTING;
3820                 } else if (oldstate == newstate) {
3821                         continue;  /* nothing new with this mds */
3822                 }
3823
3824                 /*
3825                  * send reconnect?
3826                  */
3827                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
3828                     newstate >= CEPH_MDS_STATE_RECONNECT) {
3829                         mutex_unlock(&mdsc->mutex);
3830                         send_mds_reconnect(mdsc, s);
3831                         mutex_lock(&mdsc->mutex);
3832                 }
3833
3834                 /*
3835                  * kick request on any mds that has gone active.
3836                  */
3837                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
3838                     newstate >= CEPH_MDS_STATE_ACTIVE) {
3839                         if (oldstate != CEPH_MDS_STATE_CREATING &&
3840                             oldstate != CEPH_MDS_STATE_STARTING)
3841                                 pr_info("mds%d recovery completed\n", s->s_mds);
3842                         kick_requests(mdsc, i);
3843                         ceph_kick_flushing_caps(mdsc, s);
3844                         wake_up_session_caps(s, RECONNECT);
3845                 }
3846         }
3847
3848         for (i = 0; i < newmap->m_num_mds && i < mdsc->max_sessions; i++) {
3849                 s = mdsc->sessions[i];
3850                 if (!s)
3851                         continue;
3852                 if (!ceph_mdsmap_is_laggy(newmap, i))
3853                         continue;
3854                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3855                     s->s_state == CEPH_MDS_SESSION_HUNG ||
3856                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
3857                         dout(" connecting to export targets of laggy mds%d\n",
3858                              i);
3859                         __open_export_target_sessions(mdsc, s);
3860                 }
3861         }
3862 }
3863
3864
3865
3866 /*
3867  * leases
3868  */
3869
3870 /*
3871  * caller must hold session s_mutex, dentry->d_lock
3872  */
3873 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
3874 {
3875         struct ceph_dentry_info *di = ceph_dentry(dentry);
3876
3877         ceph_put_mds_session(di->lease_session);
3878         di->lease_session = NULL;
3879 }
3880
3881 static void handle_lease(struct ceph_mds_client *mdsc,
3882                          struct ceph_mds_session *session,
3883                          struct ceph_msg *msg)
3884 {
3885         struct super_block *sb = mdsc->fsc->sb;
3886         struct inode *inode;
3887         struct dentry *parent, *dentry;
3888         struct ceph_dentry_info *di;
3889         int mds = session->s_mds;
3890         struct ceph_mds_lease *h = msg->front.iov_base;
3891         u32 seq;
3892         struct ceph_vino vino;
3893         struct qstr dname;
3894         int release = 0;
3895
3896         dout("handle_lease from mds%d\n", mds);
3897
3898         /* decode */
3899         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
3900                 goto bad;
3901         vino.ino = le64_to_cpu(h->ino);
3902         vino.snap = CEPH_NOSNAP;
3903         seq = le32_to_cpu(h->seq);
3904         dname.len = get_unaligned_le32(h + 1);
3905         if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
3906                 goto bad;
3907         dname.name = (void *)(h + 1) + sizeof(u32);
3908
3909         /* lookup inode */
3910         inode = ceph_find_inode(sb, vino);
3911         dout("handle_lease %s, ino %llx %p %.*s\n",
3912              ceph_lease_op_name(h->action), vino.ino, inode,
3913              dname.len, dname.name);
3914
3915         mutex_lock(&session->s_mutex);
3916         session->s_seq++;
3917
3918         if (!inode) {
3919                 dout("handle_lease no inode %llx\n", vino.ino);
3920                 goto release;
3921         }
3922
3923         /* dentry */
3924         parent = d_find_alias(inode);
3925         if (!parent) {
3926                 dout("no parent dentry on inode %p\n", inode);
3927                 WARN_ON(1);
3928                 goto release;  /* hrm... */
3929         }
3930         dname.hash = full_name_hash(parent, dname.name, dname.len);
3931         dentry = d_lookup(parent, &dname);
3932         dput(parent);
3933         if (!dentry)
3934                 goto release;
3935
3936         spin_lock(&dentry->d_lock);
3937         di = ceph_dentry(dentry);
3938         switch (h->action) {
3939         case CEPH_MDS_LEASE_REVOKE:
3940                 if (di->lease_session == session) {
3941                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
3942                                 h->seq = cpu_to_le32(di->lease_seq);
3943                         __ceph_mdsc_drop_dentry_lease(dentry);
3944                 }
3945                 release = 1;
3946                 break;
3947
3948         case CEPH_MDS_LEASE_RENEW:
3949                 if (di->lease_session == session &&
3950                     di->lease_gen == session->s_cap_gen &&
3951                     di->lease_renew_from &&
3952                     di->lease_renew_after == 0) {
3953                         unsigned long duration =
3954                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
3955
3956                         di->lease_seq = seq;
3957                         di->time = di->lease_renew_from + duration;
3958                         di->lease_renew_after = di->lease_renew_from +
3959                                 (duration >> 1);
3960                         di->lease_renew_from = 0;
3961                 }
3962                 break;
3963         }
3964         spin_unlock(&dentry->d_lock);
3965         dput(dentry);
3966
3967         if (!release)
3968                 goto out;
3969
3970 release:
3971         /* let's just reuse the same message */
3972         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
3973         ceph_msg_get(msg);
3974         ceph_con_send(&session->s_con, msg);
3975
3976 out:
3977         mutex_unlock(&session->s_mutex);
3978         /* avoid calling iput_final() in mds dispatch threads */
3979         ceph_async_iput(inode);
3980         return;
3981
3982 bad:
3983         pr_err("corrupt lease message\n");
3984         ceph_msg_dump(msg);
3985 }
3986
3987 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
3988                               struct dentry *dentry, char action,
3989                               u32 seq)
3990 {
3991         struct ceph_msg *msg;
3992         struct ceph_mds_lease *lease;
3993         struct inode *dir;
3994         int len = sizeof(*lease) + sizeof(u32) + NAME_MAX;
3995
3996         dout("lease_send_msg identry %p %s to mds%d\n",
3997              dentry, ceph_lease_op_name(action), session->s_mds);
3998
3999         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
4000         if (!msg)
4001                 return;
4002         lease = msg->front.iov_base;
4003         lease->action = action;
4004         lease->seq = cpu_to_le32(seq);
4005
4006         spin_lock(&dentry->d_lock);
4007         dir = d_inode(dentry->d_parent);
4008         lease->ino = cpu_to_le64(ceph_ino(dir));
4009         lease->first = lease->last = cpu_to_le64(ceph_snap(dir));
4010
4011         put_unaligned_le32(dentry->d_name.len, lease + 1);
4012         memcpy((void *)(lease + 1) + 4,
4013                dentry->d_name.name, dentry->d_name.len);
4014         spin_unlock(&dentry->d_lock);
4015         /*
4016          * if this is a preemptive lease RELEASE, no need to
4017          * flush request stream, since the actual request will
4018          * soon follow.
4019          */
4020         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
4021
4022         ceph_con_send(&session->s_con, msg);
4023 }
4024
4025 /*
4026  * lock unlock sessions, to wait ongoing session activities
4027  */
4028 static void lock_unlock_sessions(struct ceph_mds_client *mdsc)
4029 {
4030         int i;
4031
4032         mutex_lock(&mdsc->mutex);
4033         for (i = 0; i < mdsc->max_sessions; i++) {
4034                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4035                 if (!s)
4036                         continue;
4037                 mutex_unlock(&mdsc->mutex);
4038                 mutex_lock(&s->s_mutex);
4039                 mutex_unlock(&s->s_mutex);
4040                 ceph_put_mds_session(s);
4041                 mutex_lock(&mdsc->mutex);
4042         }
4043         mutex_unlock(&mdsc->mutex);
4044 }
4045
4046 static void maybe_recover_session(struct ceph_mds_client *mdsc)
4047 {
4048         struct ceph_fs_client *fsc = mdsc->fsc;
4049
4050         if (!ceph_test_mount_opt(fsc, CLEANRECOVER))
4051                 return;
4052
4053         if (READ_ONCE(fsc->mount_state) != CEPH_MOUNT_MOUNTED)
4054                 return;
4055
4056         if (!READ_ONCE(fsc->blacklisted))
4057                 return;
4058
4059         if (fsc->last_auto_reconnect &&
4060             time_before(jiffies, fsc->last_auto_reconnect + HZ * 60 * 30))
4061                 return;
4062
4063         pr_info("auto reconnect after blacklisted\n");
4064         fsc->last_auto_reconnect = jiffies;
4065         ceph_force_reconnect(fsc->sb);
4066 }
4067
4068 /*
4069  * delayed work -- periodically trim expired leases, renew caps with mds
4070  */
4071 static void schedule_delayed(struct ceph_mds_client *mdsc)
4072 {
4073         int delay = 5;
4074         unsigned hz = round_jiffies_relative(HZ * delay);
4075         schedule_delayed_work(&mdsc->delayed_work, hz);
4076 }
4077
4078 static void delayed_work(struct work_struct *work)
4079 {
4080         int i;
4081         struct ceph_mds_client *mdsc =
4082                 container_of(work, struct ceph_mds_client, delayed_work.work);
4083         int renew_interval;
4084         int renew_caps;
4085
4086         dout("mdsc delayed_work\n");
4087
4088         mutex_lock(&mdsc->mutex);
4089         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
4090         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
4091                                    mdsc->last_renew_caps);
4092         if (renew_caps)
4093                 mdsc->last_renew_caps = jiffies;
4094
4095         for (i = 0; i < mdsc->max_sessions; i++) {
4096                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4097                 if (!s)
4098                         continue;
4099                 if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
4100                         dout("resending session close request for mds%d\n",
4101                              s->s_mds);
4102                         request_close_session(mdsc, s);
4103                         ceph_put_mds_session(s);
4104                         continue;
4105                 }
4106                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
4107                         if (s->s_state == CEPH_MDS_SESSION_OPEN) {
4108                                 s->s_state = CEPH_MDS_SESSION_HUNG;
4109                                 pr_info("mds%d hung\n", s->s_mds);
4110                         }
4111                 }
4112                 if (s->s_state == CEPH_MDS_SESSION_NEW ||
4113                     s->s_state == CEPH_MDS_SESSION_RESTARTING ||
4114                     s->s_state == CEPH_MDS_SESSION_REJECTED) {
4115                         /* this mds is failed or recovering, just wait */
4116                         ceph_put_mds_session(s);
4117                         continue;
4118                 }
4119                 mutex_unlock(&mdsc->mutex);
4120
4121                 mutex_lock(&s->s_mutex);
4122                 if (renew_caps)
4123                         send_renew_caps(mdsc, s);
4124                 else
4125                         ceph_con_keepalive(&s->s_con);
4126                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4127                     s->s_state == CEPH_MDS_SESSION_HUNG)
4128                         ceph_send_cap_releases(mdsc, s);
4129                 mutex_unlock(&s->s_mutex);
4130                 ceph_put_mds_session(s);
4131
4132                 mutex_lock(&mdsc->mutex);
4133         }
4134         mutex_unlock(&mdsc->mutex);
4135
4136         ceph_check_delayed_caps(mdsc);
4137
4138         ceph_queue_cap_reclaim_work(mdsc);
4139
4140         ceph_trim_snapid_map(mdsc);
4141
4142         maybe_recover_session(mdsc);
4143
4144         schedule_delayed(mdsc);
4145 }
4146
4147 int ceph_mdsc_init(struct ceph_fs_client *fsc)
4148
4149 {
4150         struct ceph_mds_client *mdsc;
4151
4152         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
4153         if (!mdsc)
4154                 return -ENOMEM;
4155         mdsc->fsc = fsc;
4156         mutex_init(&mdsc->mutex);
4157         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
4158         if (!mdsc->mdsmap) {
4159                 kfree(mdsc);
4160                 return -ENOMEM;
4161         }
4162
4163         fsc->mdsc = mdsc;
4164         init_completion(&mdsc->safe_umount_waiters);
4165         init_waitqueue_head(&mdsc->session_close_wq);
4166         INIT_LIST_HEAD(&mdsc->waiting_for_map);
4167         mdsc->sessions = NULL;
4168         atomic_set(&mdsc->num_sessions, 0);
4169         mdsc->max_sessions = 0;
4170         mdsc->stopping = 0;
4171         atomic64_set(&mdsc->quotarealms_count, 0);
4172         mdsc->quotarealms_inodes = RB_ROOT;
4173         mutex_init(&mdsc->quotarealms_inodes_mutex);
4174         mdsc->last_snap_seq = 0;
4175         init_rwsem(&mdsc->snap_rwsem);
4176         mdsc->snap_realms = RB_ROOT;
4177         INIT_LIST_HEAD(&mdsc->snap_empty);
4178         mdsc->num_snap_realms = 0;
4179         spin_lock_init(&mdsc->snap_empty_lock);
4180         mdsc->last_tid = 0;
4181         mdsc->oldest_tid = 0;
4182         mdsc->request_tree = RB_ROOT;
4183         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
4184         mdsc->last_renew_caps = jiffies;
4185         INIT_LIST_HEAD(&mdsc->cap_delay_list);
4186         INIT_LIST_HEAD(&mdsc->cap_wait_list);
4187         spin_lock_init(&mdsc->cap_delay_lock);
4188         INIT_LIST_HEAD(&mdsc->snap_flush_list);
4189         spin_lock_init(&mdsc->snap_flush_lock);
4190         mdsc->last_cap_flush_tid = 1;
4191         INIT_LIST_HEAD(&mdsc->cap_flush_list);
4192         INIT_LIST_HEAD(&mdsc->cap_dirty);
4193         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
4194         mdsc->num_cap_flushing = 0;
4195         spin_lock_init(&mdsc->cap_dirty_lock);
4196         init_waitqueue_head(&mdsc->cap_flushing_wq);
4197         INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
4198         atomic_set(&mdsc->cap_reclaim_pending, 0);
4199
4200         spin_lock_init(&mdsc->dentry_list_lock);
4201         INIT_LIST_HEAD(&mdsc->dentry_leases);
4202         INIT_LIST_HEAD(&mdsc->dentry_dir_leases);
4203
4204         ceph_caps_init(mdsc);
4205         ceph_adjust_caps_max_min(mdsc, fsc->mount_options);
4206
4207         spin_lock_init(&mdsc->snapid_map_lock);
4208         mdsc->snapid_map_tree = RB_ROOT;
4209         INIT_LIST_HEAD(&mdsc->snapid_map_lru);
4210
4211         init_rwsem(&mdsc->pool_perm_rwsem);
4212         mdsc->pool_perm_tree = RB_ROOT;
4213
4214         strscpy(mdsc->nodename, utsname()->nodename,
4215                 sizeof(mdsc->nodename));
4216         return 0;
4217 }
4218
4219 /*
4220  * Wait for safe replies on open mds requests.  If we time out, drop
4221  * all requests from the tree to avoid dangling dentry refs.
4222  */
4223 static void wait_requests(struct ceph_mds_client *mdsc)
4224 {
4225         struct ceph_options *opts = mdsc->fsc->client->options;
4226         struct ceph_mds_request *req;
4227
4228         mutex_lock(&mdsc->mutex);
4229         if (__get_oldest_req(mdsc)) {
4230                 mutex_unlock(&mdsc->mutex);
4231
4232                 dout("wait_requests waiting for requests\n");
4233                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
4234                                     ceph_timeout_jiffies(opts->mount_timeout));
4235
4236                 /* tear down remaining requests */
4237                 mutex_lock(&mdsc->mutex);
4238                 while ((req = __get_oldest_req(mdsc))) {
4239                         dout("wait_requests timed out on tid %llu\n",
4240                              req->r_tid);
4241                         list_del_init(&req->r_wait);
4242                         __unregister_request(mdsc, req);
4243                 }
4244         }
4245         mutex_unlock(&mdsc->mutex);
4246         dout("wait_requests done\n");
4247 }
4248
4249 /*
4250  * called before mount is ro, and before dentries are torn down.
4251  * (hmm, does this still race with new lookups?)
4252  */
4253 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
4254 {
4255         dout("pre_umount\n");
4256         mdsc->stopping = 1;
4257
4258         lock_unlock_sessions(mdsc);
4259         ceph_flush_dirty_caps(mdsc);
4260         wait_requests(mdsc);
4261
4262         /*
4263          * wait for reply handlers to drop their request refs and
4264          * their inode/dcache refs
4265          */
4266         ceph_msgr_flush();
4267
4268         ceph_cleanup_quotarealms_inodes(mdsc);
4269 }
4270
4271 /*
4272  * wait for all write mds requests to flush.
4273  */
4274 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
4275 {
4276         struct ceph_mds_request *req = NULL, *nextreq;
4277         struct rb_node *n;
4278
4279         mutex_lock(&mdsc->mutex);
4280         dout("wait_unsafe_requests want %lld\n", want_tid);
4281 restart:
4282         req = __get_oldest_req(mdsc);
4283         while (req && req->r_tid <= want_tid) {
4284                 /* find next request */
4285                 n = rb_next(&req->r_node);
4286                 if (n)
4287                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
4288                 else
4289                         nextreq = NULL;
4290                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
4291                     (req->r_op & CEPH_MDS_OP_WRITE)) {
4292                         /* write op */
4293                         ceph_mdsc_get_request(req);
4294                         if (nextreq)
4295                                 ceph_mdsc_get_request(nextreq);
4296                         mutex_unlock(&mdsc->mutex);
4297                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
4298                              req->r_tid, want_tid);
4299                         wait_for_completion(&req->r_safe_completion);
4300                         mutex_lock(&mdsc->mutex);
4301                         ceph_mdsc_put_request(req);
4302                         if (!nextreq)
4303                                 break;  /* next dne before, so we're done! */
4304                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
4305                                 /* next request was removed from tree */
4306                                 ceph_mdsc_put_request(nextreq);
4307                                 goto restart;
4308                         }
4309                         ceph_mdsc_put_request(nextreq);  /* won't go away */
4310                 }
4311                 req = nextreq;
4312         }
4313         mutex_unlock(&mdsc->mutex);
4314         dout("wait_unsafe_requests done\n");
4315 }
4316
4317 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
4318 {
4319         u64 want_tid, want_flush;
4320
4321         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4322                 return;
4323
4324         dout("sync\n");
4325         mutex_lock(&mdsc->mutex);
4326         want_tid = mdsc->last_tid;
4327         mutex_unlock(&mdsc->mutex);
4328
4329         ceph_flush_dirty_caps(mdsc);
4330         spin_lock(&mdsc->cap_dirty_lock);
4331         want_flush = mdsc->last_cap_flush_tid;
4332         if (!list_empty(&mdsc->cap_flush_list)) {
4333                 struct ceph_cap_flush *cf =
4334                         list_last_entry(&mdsc->cap_flush_list,
4335                                         struct ceph_cap_flush, g_list);
4336                 cf->wake = true;
4337         }
4338         spin_unlock(&mdsc->cap_dirty_lock);
4339
4340         dout("sync want tid %lld flush_seq %lld\n",
4341              want_tid, want_flush);
4342
4343         wait_unsafe_requests(mdsc, want_tid);
4344         wait_caps_flush(mdsc, want_flush);
4345 }
4346
4347 /*
4348  * true if all sessions are closed, or we force unmount
4349  */
4350 static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
4351 {
4352         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4353                 return true;
4354         return atomic_read(&mdsc->num_sessions) <= skipped;
4355 }
4356
4357 /*
4358  * called after sb is ro.
4359  */
4360 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
4361 {
4362         struct ceph_options *opts = mdsc->fsc->client->options;
4363         struct ceph_mds_session *session;
4364         int i;
4365         int skipped = 0;
4366
4367         dout("close_sessions\n");
4368
4369         /* close sessions */
4370         mutex_lock(&mdsc->mutex);
4371         for (i = 0; i < mdsc->max_sessions; i++) {
4372                 session = __ceph_lookup_mds_session(mdsc, i);
4373                 if (!session)
4374                         continue;
4375                 mutex_unlock(&mdsc->mutex);
4376                 mutex_lock(&session->s_mutex);
4377                 if (__close_session(mdsc, session) <= 0)
4378                         skipped++;
4379                 mutex_unlock(&session->s_mutex);
4380                 ceph_put_mds_session(session);
4381                 mutex_lock(&mdsc->mutex);
4382         }
4383         mutex_unlock(&mdsc->mutex);
4384
4385         dout("waiting for sessions to close\n");
4386         wait_event_timeout(mdsc->session_close_wq,
4387                            done_closing_sessions(mdsc, skipped),
4388                            ceph_timeout_jiffies(opts->mount_timeout));
4389
4390         /* tear down remaining sessions */
4391         mutex_lock(&mdsc->mutex);
4392         for (i = 0; i < mdsc->max_sessions; i++) {
4393                 if (mdsc->sessions[i]) {
4394                         session = get_session(mdsc->sessions[i]);
4395                         __unregister_session(mdsc, session);
4396                         mutex_unlock(&mdsc->mutex);
4397                         mutex_lock(&session->s_mutex);
4398                         remove_session_caps(session);
4399                         mutex_unlock(&session->s_mutex);
4400                         ceph_put_mds_session(session);
4401                         mutex_lock(&mdsc->mutex);
4402                 }
4403         }
4404         WARN_ON(!list_empty(&mdsc->cap_delay_list));
4405         mutex_unlock(&mdsc->mutex);
4406
4407         ceph_cleanup_snapid_map(mdsc);
4408         ceph_cleanup_empty_realms(mdsc);
4409
4410         cancel_work_sync(&mdsc->cap_reclaim_work);
4411         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4412
4413         dout("stopped\n");
4414 }
4415
4416 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
4417 {
4418         struct ceph_mds_session *session;
4419         int mds;
4420
4421         dout("force umount\n");
4422
4423         mutex_lock(&mdsc->mutex);
4424         for (mds = 0; mds < mdsc->max_sessions; mds++) {
4425                 session = __ceph_lookup_mds_session(mdsc, mds);
4426                 if (!session)
4427                         continue;
4428
4429                 if (session->s_state == CEPH_MDS_SESSION_REJECTED)
4430                         __unregister_session(mdsc, session);
4431                 __wake_requests(mdsc, &session->s_waiting);
4432                 mutex_unlock(&mdsc->mutex);
4433
4434                 mutex_lock(&session->s_mutex);
4435                 __close_session(mdsc, session);
4436                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
4437                         cleanup_session_requests(mdsc, session);
4438                         remove_session_caps(session);
4439                 }
4440                 mutex_unlock(&session->s_mutex);
4441                 ceph_put_mds_session(session);
4442
4443                 mutex_lock(&mdsc->mutex);
4444                 kick_requests(mdsc, mds);
4445         }
4446         __wake_requests(mdsc, &mdsc->waiting_for_map);
4447         mutex_unlock(&mdsc->mutex);
4448 }
4449
4450 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
4451 {
4452         dout("stop\n");
4453         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4454         if (mdsc->mdsmap)
4455                 ceph_mdsmap_destroy(mdsc->mdsmap);
4456         kfree(mdsc->sessions);
4457         ceph_caps_finalize(mdsc);
4458         ceph_pool_perm_destroy(mdsc);
4459 }
4460
4461 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
4462 {
4463         struct ceph_mds_client *mdsc = fsc->mdsc;
4464         dout("mdsc_destroy %p\n", mdsc);
4465
4466         if (!mdsc)
4467                 return;
4468
4469         /* flush out any connection work with references to us */
4470         ceph_msgr_flush();
4471
4472         ceph_mdsc_stop(mdsc);
4473
4474         fsc->mdsc = NULL;
4475         kfree(mdsc);
4476         dout("mdsc_destroy %p done\n", mdsc);
4477 }
4478
4479 void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4480 {
4481         struct ceph_fs_client *fsc = mdsc->fsc;
4482         const char *mds_namespace = fsc->mount_options->mds_namespace;
4483         void *p = msg->front.iov_base;
4484         void *end = p + msg->front.iov_len;
4485         u32 epoch;
4486         u32 map_len;
4487         u32 num_fs;
4488         u32 mount_fscid = (u32)-1;
4489         u8 struct_v, struct_cv;
4490         int err = -EINVAL;
4491
4492         ceph_decode_need(&p, end, sizeof(u32), bad);
4493         epoch = ceph_decode_32(&p);
4494
4495         dout("handle_fsmap epoch %u\n", epoch);
4496
4497         ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4498         struct_v = ceph_decode_8(&p);
4499         struct_cv = ceph_decode_8(&p);
4500         map_len = ceph_decode_32(&p);
4501
4502         ceph_decode_need(&p, end, sizeof(u32) * 3, bad);
4503         p += sizeof(u32) * 2; /* skip epoch and legacy_client_fscid */
4504
4505         num_fs = ceph_decode_32(&p);
4506         while (num_fs-- > 0) {
4507                 void *info_p, *info_end;
4508                 u32 info_len;
4509                 u8 info_v, info_cv;
4510                 u32 fscid, namelen;
4511
4512                 ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
4513                 info_v = ceph_decode_8(&p);
4514                 info_cv = ceph_decode_8(&p);
4515                 info_len = ceph_decode_32(&p);
4516                 ceph_decode_need(&p, end, info_len, bad);
4517                 info_p = p;
4518                 info_end = p + info_len;
4519                 p = info_end;
4520
4521                 ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
4522                 fscid = ceph_decode_32(&info_p);
4523                 namelen = ceph_decode_32(&info_p);
4524                 ceph_decode_need(&info_p, info_end, namelen, bad);
4525
4526                 if (mds_namespace &&
4527                     strlen(mds_namespace) == namelen &&
4528                     !strncmp(mds_namespace, (char *)info_p, namelen)) {
4529                         mount_fscid = fscid;
4530                         break;
4531                 }
4532         }
4533
4534         ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
4535         if (mount_fscid != (u32)-1) {
4536                 fsc->client->monc.fs_cluster_id = mount_fscid;
4537                 ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
4538                                    0, true);
4539                 ceph_monc_renew_subs(&fsc->client->monc);
4540         } else {
4541                 err = -ENOENT;
4542                 goto err_out;
4543         }
4544         return;
4545
4546 bad:
4547         pr_err("error decoding fsmap\n");
4548 err_out:
4549         mutex_lock(&mdsc->mutex);
4550         mdsc->mdsmap_err = err;
4551         __wake_requests(mdsc, &mdsc->waiting_for_map);
4552         mutex_unlock(&mdsc->mutex);
4553 }
4554
4555 /*
4556  * handle mds map update.
4557  */
4558 void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
4559 {
4560         u32 epoch;
4561         u32 maplen;
4562         void *p = msg->front.iov_base;
4563         void *end = p + msg->front.iov_len;
4564         struct ceph_mdsmap *newmap, *oldmap;
4565         struct ceph_fsid fsid;
4566         int err = -EINVAL;
4567
4568         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
4569         ceph_decode_copy(&p, &fsid, sizeof(fsid));
4570         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
4571                 return;
4572         epoch = ceph_decode_32(&p);
4573         maplen = ceph_decode_32(&p);
4574         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
4575
4576         /* do we need it? */
4577         mutex_lock(&mdsc->mutex);
4578         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
4579                 dout("handle_map epoch %u <= our %u\n",
4580                      epoch, mdsc->mdsmap->m_epoch);
4581                 mutex_unlock(&mdsc->mutex);
4582                 return;
4583         }
4584
4585         newmap = ceph_mdsmap_decode(&p, end);
4586         if (IS_ERR(newmap)) {
4587                 err = PTR_ERR(newmap);
4588                 goto bad_unlock;
4589         }
4590
4591         /* swap into place */
4592         if (mdsc->mdsmap) {
4593                 oldmap = mdsc->mdsmap;
4594                 mdsc->mdsmap = newmap;
4595                 check_new_map(mdsc, newmap, oldmap);
4596                 ceph_mdsmap_destroy(oldmap);
4597         } else {
4598                 mdsc->mdsmap = newmap;  /* first mds map */
4599         }
4600         mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
4601                                         MAX_LFS_FILESIZE);
4602
4603         __wake_requests(mdsc, &mdsc->waiting_for_map);
4604         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
4605                           mdsc->mdsmap->m_epoch);
4606
4607         mutex_unlock(&mdsc->mutex);
4608         schedule_delayed(mdsc);
4609         return;
4610
4611 bad_unlock:
4612         mutex_unlock(&mdsc->mutex);
4613 bad:
4614         pr_err("error decoding mdsmap %d\n", err);
4615         return;
4616 }
4617
4618 static struct ceph_connection *con_get(struct ceph_connection *con)
4619 {
4620         struct ceph_mds_session *s = con->private;
4621
4622         if (get_session(s))
4623                 return con;
4624         return NULL;
4625 }
4626
4627 static void con_put(struct ceph_connection *con)
4628 {
4629         struct ceph_mds_session *s = con->private;
4630
4631         ceph_put_mds_session(s);
4632 }
4633
4634 /*
4635  * if the client is unresponsive for long enough, the mds will kill
4636  * the session entirely.
4637  */
4638 static void peer_reset(struct ceph_connection *con)
4639 {
4640         struct ceph_mds_session *s = con->private;
4641         struct ceph_mds_client *mdsc = s->s_mdsc;
4642
4643         pr_warn("mds%d closed our session\n", s->s_mds);
4644         send_mds_reconnect(mdsc, s);
4645 }
4646
4647 static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
4648 {
4649         struct ceph_mds_session *s = con->private;
4650         struct ceph_mds_client *mdsc = s->s_mdsc;
4651         int type = le16_to_cpu(msg->hdr.type);
4652
4653         mutex_lock(&mdsc->mutex);
4654         if (__verify_registered_session(mdsc, s) < 0) {
4655                 mutex_unlock(&mdsc->mutex);
4656                 goto out;
4657         }
4658         mutex_unlock(&mdsc->mutex);
4659
4660         switch (type) {
4661         case CEPH_MSG_MDS_MAP:
4662                 ceph_mdsc_handle_mdsmap(mdsc, msg);
4663                 break;
4664         case CEPH_MSG_FS_MAP_USER:
4665                 ceph_mdsc_handle_fsmap(mdsc, msg);
4666                 break;
4667         case CEPH_MSG_CLIENT_SESSION:
4668                 handle_session(s, msg);
4669                 break;
4670         case CEPH_MSG_CLIENT_REPLY:
4671                 handle_reply(s, msg);
4672                 break;
4673         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
4674                 handle_forward(mdsc, s, msg);
4675                 break;
4676         case CEPH_MSG_CLIENT_CAPS:
4677                 ceph_handle_caps(s, msg);
4678                 break;
4679         case CEPH_MSG_CLIENT_SNAP:
4680                 ceph_handle_snap(mdsc, s, msg);
4681                 break;
4682         case CEPH_MSG_CLIENT_LEASE:
4683                 handle_lease(mdsc, s, msg);
4684                 break;
4685         case CEPH_MSG_CLIENT_QUOTA:
4686                 ceph_handle_quota(mdsc, s, msg);
4687                 break;
4688
4689         default:
4690                 pr_err("received unknown message type %d %s\n", type,
4691                        ceph_msg_type_name(type));
4692         }
4693 out:
4694         ceph_msg_put(msg);
4695 }
4696
4697 /*
4698  * authentication
4699  */
4700
4701 /*
4702  * Note: returned pointer is the address of a structure that's
4703  * managed separately.  Caller must *not* attempt to free it.
4704  */
4705 static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
4706                                         int *proto, int force_new)
4707 {
4708         struct ceph_mds_session *s = con->private;
4709         struct ceph_mds_client *mdsc = s->s_mdsc;
4710         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4711         struct ceph_auth_handshake *auth = &s->s_auth;
4712
4713         if (force_new && auth->authorizer) {
4714                 ceph_auth_destroy_authorizer(auth->authorizer);
4715                 auth->authorizer = NULL;
4716         }
4717         if (!auth->authorizer) {
4718                 int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4719                                                       auth);
4720                 if (ret)
4721                         return ERR_PTR(ret);
4722         } else {
4723                 int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
4724                                                       auth);
4725                 if (ret)
4726                         return ERR_PTR(ret);
4727         }
4728         *proto = ac->protocol;
4729
4730         return auth;
4731 }
4732
4733 static int add_authorizer_challenge(struct ceph_connection *con,
4734                                     void *challenge_buf, int challenge_buf_len)
4735 {
4736         struct ceph_mds_session *s = con->private;
4737         struct ceph_mds_client *mdsc = s->s_mdsc;
4738         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4739
4740         return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
4741                                             challenge_buf, challenge_buf_len);
4742 }
4743
4744 static int verify_authorizer_reply(struct ceph_connection *con)
4745 {
4746         struct ceph_mds_session *s = con->private;
4747         struct ceph_mds_client *mdsc = s->s_mdsc;
4748         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4749
4750         return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer);
4751 }
4752
4753 static int invalidate_authorizer(struct ceph_connection *con)
4754 {
4755         struct ceph_mds_session *s = con->private;
4756         struct ceph_mds_client *mdsc = s->s_mdsc;
4757         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
4758
4759         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
4760
4761         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
4762 }
4763
4764 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
4765                                 struct ceph_msg_header *hdr, int *skip)
4766 {
4767         struct ceph_msg *msg;
4768         int type = (int) le16_to_cpu(hdr->type);
4769         int front_len = (int) le32_to_cpu(hdr->front_len);
4770
4771         if (con->in_msg)
4772                 return con->in_msg;
4773
4774         *skip = 0;
4775         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
4776         if (!msg) {
4777                 pr_err("unable to allocate msg type %d len %d\n",
4778                        type, front_len);
4779                 return NULL;
4780         }
4781
4782         return msg;
4783 }
4784
4785 static int mds_sign_message(struct ceph_msg *msg)
4786 {
4787        struct ceph_mds_session *s = msg->con->private;
4788        struct ceph_auth_handshake *auth = &s->s_auth;
4789
4790        return ceph_auth_sign_message(auth, msg);
4791 }
4792
4793 static int mds_check_message_signature(struct ceph_msg *msg)
4794 {
4795        struct ceph_mds_session *s = msg->con->private;
4796        struct ceph_auth_handshake *auth = &s->s_auth;
4797
4798        return ceph_auth_check_message_signature(auth, msg);
4799 }
4800
4801 static const struct ceph_connection_operations mds_con_ops = {
4802         .get = con_get,
4803         .put = con_put,
4804         .dispatch = dispatch,
4805         .get_authorizer = get_authorizer,
4806         .add_authorizer_challenge = add_authorizer_challenge,
4807         .verify_authorizer_reply = verify_authorizer_reply,
4808         .invalidate_authorizer = invalidate_authorizer,
4809         .peer_reset = peer_reset,
4810         .alloc_msg = mds_alloc_msg,
4811         .sign_message = mds_sign_message,
4812         .check_message_signature = mds_check_message_signature,
4813 };
4814
4815 /* eof */