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 #include <linux/bits.h>
  13 #include <linux/ktime.h>
  14 #include <linux/bitmap.h>
  15
  16 #include "super.h"
  17 #include "mds_client.h"
  18
  19 #include <linux/ceph/ceph_features.h>
  20 #include <linux/ceph/messenger.h>
  21 #include <linux/ceph/decode.h>
  22 #include <linux/ceph/pagelist.h>
  23 #include <linux/ceph/auth.h>
  24 #include <linux/ceph/debugfs.h>
  25
  26 #define RECONNECT_MAX_SIZE (INT_MAX - PAGE_SIZE)
  27
  28 /*
  29  * A cluster of MDS (metadata server) daemons is responsible for
  30  * managing the file system namespace (the directory hierarchy and
  31  * inodes) and for coordinating shared access to storage.  Metadata is
  32  * partitioning hierarchically across a number of servers, and that
  33  * partition varies over time as the cluster adjusts the distribution
  34  * in order to balance load.
  35  *
  36  * The MDS client is primarily responsible to managing synchronous
  37  * metadata requests for operations like open, unlink, and so forth.
  38  * If there is a MDS failure, we find out about it when we (possibly
  39  * request and) receive a new MDS map, and can resubmit affected
  40  * requests.
  41  *
  42  * For the most part, though, we take advantage of a lossless
  43  * communications channel to the MDS, and do not need to worry about
  44  * timing out or resubmitting requests.
  45  *
  46  * We maintain a stateful "session" with each MDS we interact with.
  47  * Within each session, we sent periodic heartbeat messages to ensure
  48  * any capabilities or leases we have been issues remain valid.  If
  49  * the session times out and goes stale, our leases and capabilities
  50  * are no longer valid.
  51  */
  52
  53 struct ceph_reconnect_state {
  54         struct ceph_mds_session *session;
  55         int nr_caps, nr_realms;
  56         struct ceph_pagelist *pagelist;
  57         unsigned msg_version;
  58         bool allow_multi;
  59 };
  60
  61 static void __wake_requests(struct ceph_mds_client *mdsc,
  62                             struct list_head *head);
  63 static void ceph_cap_release_work(struct work_struct *work);
  64 static void ceph_cap_reclaim_work(struct work_struct *work);
  65
  66 static const struct ceph_connection_operations mds_con_ops;
  67
  68
  69 /*
  70  * mds reply parsing
  71  */
  72
  73 static int parse_reply_info_quota(void **p, void *end,
  74                                   struct ceph_mds_reply_info_in *info)
  75 {
  76         u8 struct_v, struct_compat;
  77         u32 struct_len;
  78
  79         ceph_decode_8_safe(p, end, struct_v, bad);
  80         ceph_decode_8_safe(p, end, struct_compat, bad);
  81         /* struct_v is expected to be >= 1. we only
  82          * understand encoding with struct_compat == 1. */
  83         if (!struct_v || struct_compat != 1)
  84                 goto bad;
  85         ceph_decode_32_safe(p, end, struct_len, bad);
  86         ceph_decode_need(p, end, struct_len, bad);
  87         end = *p + struct_len;
  88         ceph_decode_64_safe(p, end, info->max_bytes, bad);
  89         ceph_decode_64_safe(p, end, info->max_files, bad);
  90         *p = end;
  91         return 0;
  92 bad:
  93         return -EIO;
  94 }
  95
  96 /*
  97  * parse individual inode info
  98  */
  99 static int parse_reply_info_in(void **p, void *end,
 100                                struct ceph_mds_reply_info_in *info,
 101                                u64 features)
 102 {
 103         int err = 0;
 104         u8 struct_v = 0;
 105
 106         if (features == (u64)-1) {
 107                 u32 struct_len;
 108                 u8 struct_compat;
 109                 ceph_decode_8_safe(p, end, struct_v, bad);
 110                 ceph_decode_8_safe(p, end, struct_compat, bad);
 111                 /* struct_v is expected to be >= 1. we only understand
 112                  * encoding with struct_compat == 1. */
 113                 if (!struct_v || struct_compat != 1)
 114                         goto bad;
 115                 ceph_decode_32_safe(p, end, struct_len, bad);
 116                 ceph_decode_need(p, end, struct_len, bad);
 117                 end = *p + struct_len;
 118         }
 119
 120         ceph_decode_need(p, end, sizeof(struct ceph_mds_reply_inode), bad);
 121         info->in = *p;
 122         *p += sizeof(struct ceph_mds_reply_inode) +
 123                 sizeof(*info->in->fragtree.splits) *
 124                 le32_to_cpu(info->in->fragtree.nsplits);
 125
 126         ceph_decode_32_safe(p, end, info->symlink_len, bad);
 127         ceph_decode_need(p, end, info->symlink_len, bad);
 128         info->symlink = *p;
 129         *p += info->symlink_len;
 130
 131         ceph_decode_copy_safe(p, end, &info->dir_layout,
 132                               sizeof(info->dir_layout), bad);
 133         ceph_decode_32_safe(p, end, info->xattr_len, bad);
 134         ceph_decode_need(p, end, info->xattr_len, bad);
 135         info->xattr_data = *p;
 136         *p += info->xattr_len;
 137
 138         if (features == (u64)-1) {
 139                 /* inline data */
 140                 ceph_decode_64_safe(p, end, info->inline_version, bad);
 141                 ceph_decode_32_safe(p, end, info->inline_len, bad);
 142                 ceph_decode_need(p, end, info->inline_len, bad);
 143                 info->inline_data = *p;
 144                 *p += info->inline_len;
 145                 /* quota */
 146                 err = parse_reply_info_quota(p, end, info);
 147                 if (err < 0)
 148                         goto out_bad;
 149                 /* pool namespace */
 150                 ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 151                 if (info->pool_ns_len > 0) {
 152                         ceph_decode_need(p, end, info->pool_ns_len, bad);
 153                         info->pool_ns_data = *p;
 154                         *p += info->pool_ns_len;
 155                 }
 156
 157                 /* btime */
 158                 ceph_decode_need(p, end, sizeof(info->btime), bad);
 159                 ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 160
 161                 /* change attribute */
 162                 ceph_decode_64_safe(p, end, info->change_attr, bad);
 163
 164                 /* dir pin */
 165                 if (struct_v >= 2) {
 166                         ceph_decode_32_safe(p, end, info->dir_pin, bad);
 167                 } else {
 168                         info->dir_pin = -ENODATA;
 169                 }
 170
 171                 /* snapshot birth time, remains zero for v<=2 */
 172                 if (struct_v >= 3) {
 173                         ceph_decode_need(p, end, sizeof(info->snap_btime), bad);
 174                         ceph_decode_copy(p, &info->snap_btime,
 175                                          sizeof(info->snap_btime));
 176                 } else {
 177                         memset(&info->snap_btime, 0, sizeof(info->snap_btime));
 178                 }
 179
 180                 /* snapshot count, remains zero for v<=3 */
 181                 if (struct_v >= 4) {
 182                         ceph_decode_64_safe(p, end, info->rsnaps, bad);
 183                 } else {
 184                         info->rsnaps = 0;
 185                 }
 186
 187                 *p = end;
 188         } else {
 189                 if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
 190                         ceph_decode_64_safe(p, end, info->inline_version, bad);
 191                         ceph_decode_32_safe(p, end, info->inline_len, bad);
 192                         ceph_decode_need(p, end, info->inline_len, bad);
 193                         info->inline_data = *p;
 194                         *p += info->inline_len;
 195                 } else
 196                         info->inline_version = CEPH_INLINE_NONE;
 197
 198                 if (features & CEPH_FEATURE_MDS_QUOTA) {
 199                         err = parse_reply_info_quota(p, end, info);
 200                         if (err < 0)
 201                                 goto out_bad;
 202                 } else {
 203                         info->max_bytes = 0;
 204                         info->max_files = 0;
 205                 }
 206
 207                 info->pool_ns_len = 0;
 208                 info->pool_ns_data = NULL;
 209                 if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
 210                         ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
 211                         if (info->pool_ns_len > 0) {
 212                                 ceph_decode_need(p, end, info->pool_ns_len, bad);
 213                                 info->pool_ns_data = *p;
 214                                 *p += info->pool_ns_len;
 215                         }
 216                 }
 217
 218                 if (features & CEPH_FEATURE_FS_BTIME) {
 219                         ceph_decode_need(p, end, sizeof(info->btime), bad);
 220                         ceph_decode_copy(p, &info->btime, sizeof(info->btime));
 221                         ceph_decode_64_safe(p, end, info->change_attr, bad);
 222                 }
 223
 224                 info->dir_pin = -ENODATA;
 225                 /* info->snap_btime and info->rsnaps remain zero */
 226         }
 227         return 0;
 228 bad:
 229         err = -EIO;
 230 out_bad:
 231         return err;
 232 }
 233
 234 static int parse_reply_info_dir(void **p, void *end,
 235                                 struct ceph_mds_reply_dirfrag **dirfrag,
 236                                 u64 features)
 237 {
 238         if (features == (u64)-1) {
 239                 u8 struct_v, struct_compat;
 240                 u32 struct_len;
 241                 ceph_decode_8_safe(p, end, struct_v, bad);
 242                 ceph_decode_8_safe(p, end, struct_compat, bad);
 243                 /* struct_v is expected to be >= 1. we only understand
 244                  * encoding whose struct_compat == 1. */
 245                 if (!struct_v || struct_compat != 1)
 246                         goto bad;
 247                 ceph_decode_32_safe(p, end, struct_len, bad);
 248                 ceph_decode_need(p, end, struct_len, bad);
 249                 end = *p + struct_len;
 250         }
 251
 252         ceph_decode_need(p, end, sizeof(**dirfrag), bad);
 253         *dirfrag = *p;
 254         *p += sizeof(**dirfrag) + sizeof(u32) * le32_to_cpu((*dirfrag)->ndist);
 255         if (unlikely(*p > end))
 256                 goto bad;
 257         if (features == (u64)-1)
 258                 *p = end;
 259         return 0;
 260 bad:
 261         return -EIO;
 262 }
 263
 264 static int parse_reply_info_lease(void **p, void *end,
 265                                   struct ceph_mds_reply_lease **lease,
 266                                   u64 features)
 267 {
 268         if (features == (u64)-1) {
 269                 u8 struct_v, struct_compat;
 270                 u32 struct_len;
 271                 ceph_decode_8_safe(p, end, struct_v, bad);
 272                 ceph_decode_8_safe(p, end, struct_compat, bad);
 273                 /* struct_v is expected to be >= 1. we only understand
 274                  * encoding whose struct_compat == 1. */
 275                 if (!struct_v || struct_compat != 1)
 276                         goto bad;
 277                 ceph_decode_32_safe(p, end, struct_len, bad);
 278                 ceph_decode_need(p, end, struct_len, bad);
 279                 end = *p + struct_len;
 280         }
 281
 282         ceph_decode_need(p, end, sizeof(**lease), bad);
 283         *lease = *p;
 284         *p += sizeof(**lease);
 285         if (features == (u64)-1)
 286                 *p = end;
 287         return 0;
 288 bad:
 289         return -EIO;
 290 }
 291
 292 /*
 293  * parse a normal reply, which may contain a (dir+)dentry and/or a
 294  * target inode.
 295  */
 296 static int parse_reply_info_trace(void **p, void *end,
 297                                   struct ceph_mds_reply_info_parsed *info,
 298                                   u64 features)
 299 {
 300         int err;
 301
 302         if (info->head->is_dentry) {
 303                 err = parse_reply_info_in(p, end, &info->diri, features);
 304                 if (err < 0)
 305                         goto out_bad;
 306
 307                 err = parse_reply_info_dir(p, end, &info->dirfrag, features);
 308                 if (err < 0)
 309                         goto out_bad;
 310
 311                 ceph_decode_32_safe(p, end, info->dname_len, bad);
 312                 ceph_decode_need(p, end, info->dname_len, bad);
 313                 info->dname = *p;
 314                 *p += info->dname_len;
 315
 316                 err = parse_reply_info_lease(p, end, &info->dlease, features);
 317                 if (err < 0)
 318                         goto out_bad;
 319         }
 320
 321         if (info->head->is_target) {
 322                 err = parse_reply_info_in(p, end, &info->targeti, features);
 323                 if (err < 0)
 324                         goto out_bad;
 325         }
 326
 327         if (unlikely(*p != end))
 328                 goto bad;
 329         return 0;
 330
 331 bad:
 332         err = -EIO;
 333 out_bad:
 334         pr_err("problem parsing mds trace %d\n", err);
 335         return err;
 336 }
 337
 338 /*
 339  * parse readdir results
 340  */
 341 static int parse_reply_info_readdir(void **p, void *end,
 342                                 struct ceph_mds_reply_info_parsed *info,
 343                                 u64 features)
 344 {
 345         u32 num, i = 0;
 346         int err;
 347
 348         err = parse_reply_info_dir(p, end, &info->dir_dir, features);
 349         if (err < 0)
 350                 goto out_bad;
 351
 352         ceph_decode_need(p, end, sizeof(num) + 2, bad);
 353         num = ceph_decode_32(p);
 354         {
 355                 u16 flags = ceph_decode_16(p);
 356                 info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
 357                 info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
 358                 info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
 359                 info->offset_hash = !!(flags & CEPH_READDIR_OFFSET_HASH);
 360         }
 361         if (num == 0)
 362                 goto done;
 363
 364         BUG_ON(!info->dir_entries);
 365         if ((unsigned long)(info->dir_entries + num) >
 366             (unsigned long)info->dir_entries + info->dir_buf_size) {
 367                 pr_err("dir contents are larger than expected\n");
 368                 WARN_ON(1);
 369                 goto bad;
 370         }
 371
 372         info->dir_nr = num;
 373         while (num) {
 374                 struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 375                 /* dentry */
 376                 ceph_decode_32_safe(p, end, rde->name_len, bad);
 377                 ceph_decode_need(p, end, rde->name_len, bad);
 378                 rde->name = *p;
 379                 *p += rde->name_len;
 380                 dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
 381
 382                 /* dentry lease */
 383                 err = parse_reply_info_lease(p, end, &rde->lease, features);
 384                 if (err)
 385                         goto out_bad;
 386                 /* inode */
 387                 err = parse_reply_info_in(p, end, &rde->inode, features);
 388                 if (err < 0)
 389                         goto out_bad;
 390                 /* ceph_readdir_prepopulate() will update it */
 391                 rde->offset = 0;
 392                 i++;
 393                 num--;
 394         }
 395
 396 done:
 397         /* Skip over any unrecognized fields */
 398         *p = end;
 399         return 0;
 400
 401 bad:
 402         err = -EIO;
 403 out_bad:
 404         pr_err("problem parsing dir contents %d\n", err);
 405         return err;
 406 }
 407
 408 /*
 409  * parse fcntl F_GETLK results
 410  */
 411 static int parse_reply_info_filelock(void **p, void *end,
 412                                      struct ceph_mds_reply_info_parsed *info,
 413                                      u64 features)
 414 {
 415         if (*p + sizeof(*info->filelock_reply) > end)
 416                 goto bad;
 417
 418         info->filelock_reply = *p;
 419
 420         /* Skip over any unrecognized fields */
 421         *p = end;
 422         return 0;
 423 bad:
 424         return -EIO;
 425 }
 426
 427
 428 #if BITS_PER_LONG == 64
 429
 430 #define DELEGATED_INO_AVAILABLE         xa_mk_value(1)
 431
 432 static int ceph_parse_deleg_inos(void **p, void *end,
 433                                  struct ceph_mds_session *s)
 434 {
 435         u32 sets;
 436
 437         ceph_decode_32_safe(p, end, sets, bad);
 438         dout("got %u sets of delegated inodes\n", sets);
 439         while (sets--) {
 440                 u64 start, len, ino;
 441
 442                 ceph_decode_64_safe(p, end, start, bad);
 443                 ceph_decode_64_safe(p, end, len, bad);
 444
 445                 /* Don't accept a delegation of system inodes */
 446                 if (start < CEPH_INO_SYSTEM_BASE) {
 447                         pr_warn_ratelimited("ceph: ignoring reserved inode range delegation (start=0x%llx len=0x%llx)\n",
 448                                         start, len);
 449                         continue;
 450                 }
 451                 while (len--) {
 452                         int err = xa_insert(&s->s_delegated_inos, ino = start++,
 453                                             DELEGATED_INO_AVAILABLE,
 454                                             GFP_KERNEL);
 455                         if (!err) {
 456                                 dout("added delegated inode 0x%llx\n",
 457                                      start - 1);
 458                         } else if (err == -EBUSY) {
 459                                 pr_warn("ceph: MDS delegated inode 0x%llx more than once.\n",
 460                                         start - 1);
 461                         } else {
 462                                 return err;
 463                         }
 464                 }
 465         }
 466         return 0;
 467 bad:
 468         return -EIO;
 469 }
 470
 471 u64 ceph_get_deleg_ino(struct ceph_mds_session *s)
 472 {
 473         unsigned long ino;
 474         void *val;
 475
 476         xa_for_each(&s->s_delegated_inos, ino, val) {
 477                 val = xa_erase(&s->s_delegated_inos, ino);
 478                 if (val == DELEGATED_INO_AVAILABLE)
 479                         return ino;
 480         }
 481         return 0;
 482 }
 483
 484 int ceph_restore_deleg_ino(struct ceph_mds_session *s, u64 ino)
 485 {
 486         return xa_insert(&s->s_delegated_inos, ino, DELEGATED_INO_AVAILABLE,
 487                          GFP_KERNEL);
 488 }
 489 #else /* BITS_PER_LONG == 64 */
 490 /*
 491  * FIXME: xarrays can't handle 64-bit indexes on a 32-bit arch. For now, just
 492  * ignore delegated_inos on 32 bit arch. Maybe eventually add xarrays for top
 493  * and bottom words?
 494  */
 495 static int ceph_parse_deleg_inos(void **p, void *end,
 496                                  struct ceph_mds_session *s)
 497 {
 498         u32 sets;
 499
 500         ceph_decode_32_safe(p, end, sets, bad);
 501         if (sets)
 502                 ceph_decode_skip_n(p, end, sets * 2 * sizeof(__le64), bad);
 503         return 0;
 504 bad:
 505         return -EIO;
 506 }
 507
 508 u64 ceph_get_deleg_ino(struct ceph_mds_session *s)
 509 {
 510         return 0;
 511 }
 512
 513 int ceph_restore_deleg_ino(struct ceph_mds_session *s, u64 ino)
 514 {
 515         return 0;
 516 }
 517 #endif /* BITS_PER_LONG == 64 */
 518
 519 /*
 520  * parse create results
 521  */
 522 static int parse_reply_info_create(void **p, void *end,
 523                                   struct ceph_mds_reply_info_parsed *info,
 524                                   u64 features, struct ceph_mds_session *s)
 525 {
 526         int ret;
 527
 528         if (features == (u64)-1 ||
 529             (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
 530                 if (*p == end) {
 531                         /* Malformed reply? */
 532                         info->has_create_ino = false;
 533                 } else if (test_bit(CEPHFS_FEATURE_DELEG_INO, &s->s_features)) {
 534                         info->has_create_ino = true;
 535                         /* struct_v, struct_compat, and len */
 536                         ceph_decode_skip_n(p, end, 2 + sizeof(u32), bad);
 537                         ceph_decode_64_safe(p, end, info->ino, bad);
 538                         ret = ceph_parse_deleg_inos(p, end, s);
 539                         if (ret)
 540                                 return ret;
 541                 } else {
 542                         /* legacy */
 543                         ceph_decode_64_safe(p, end, info->ino, bad);
 544                         info->has_create_ino = true;
 545                 }
 546         } else {
 547                 if (*p != end)
 548                         goto bad;
 549         }
 550
 551         /* Skip over any unrecognized fields */
 552         *p = end;
 553         return 0;
 554 bad:
 555         return -EIO;
 556 }
 557
 558 /*
 559  * parse extra results
 560  */
 561 static int parse_reply_info_extra(void **p, void *end,
 562                                   struct ceph_mds_reply_info_parsed *info,
 563                                   u64 features, struct ceph_mds_session *s)
 564 {
 565         u32 op = le32_to_cpu(info->head->op);
 566
 567         if (op == CEPH_MDS_OP_GETFILELOCK)
 568                 return parse_reply_info_filelock(p, end, info, features);
 569         else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 570                 return parse_reply_info_readdir(p, end, info, features);
 571         else if (op == CEPH_MDS_OP_CREATE)
 572                 return parse_reply_info_create(p, end, info, features, s);
 573         else
 574                 return -EIO;
 575 }
 576
 577 /*
 578  * parse entire mds reply
 579  */
 580 static int parse_reply_info(struct ceph_mds_session *s, struct ceph_msg *msg,
 581                             struct ceph_mds_reply_info_parsed *info,
 582                             u64 features)
 583 {
 584         void *p, *end;
 585         u32 len;
 586         int err;
 587
 588         info->head = msg->front.iov_base;
 589         p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 590         end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 591
 592         /* trace */
 593         ceph_decode_32_safe(&p, end, len, bad);
 594         if (len > 0) {
 595                 ceph_decode_need(&p, end, len, bad);
 596                 err = parse_reply_info_trace(&p, p+len, info, features);
 597                 if (err < 0)
 598                         goto out_bad;
 599         }
 600
 601         /* extra */
 602         ceph_decode_32_safe(&p, end, len, bad);
 603         if (len > 0) {
 604                 ceph_decode_need(&p, end, len, bad);
 605                 err = parse_reply_info_extra(&p, p+len, info, features, s);
 606                 if (err < 0)
 607                         goto out_bad;
 608         }
 609
 610         /* snap blob */
 611         ceph_decode_32_safe(&p, end, len, bad);
 612         info->snapblob_len = len;
 613         info->snapblob = p;
 614         p += len;
 615
 616         if (p != end)
 617                 goto bad;
 618         return 0;
 619
 620 bad:
 621         err = -EIO;
 622 out_bad:
 623         pr_err("mds parse_reply err %d\n", err);
 624         return err;
 625 }
 626
 627 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 628 {
 629         if (!info->dir_entries)
 630                 return;
 631         free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 632 }
 633
 634
 635 /*
 636  * sessions
 637  */
 638 const char *ceph_session_state_name(int s)
 639 {
 640         switch (s) {
 641         case CEPH_MDS_SESSION_NEW: return "new";
 642         case CEPH_MDS_SESSION_OPENING: return "opening";
 643         case CEPH_MDS_SESSION_OPEN: return "open";
 644         case CEPH_MDS_SESSION_HUNG: return "hung";
 645         case CEPH_MDS_SESSION_CLOSING: return "closing";
 646         case CEPH_MDS_SESSION_CLOSED: return "closed";
 647         case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 648         case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 649         case CEPH_MDS_SESSION_REJECTED: return "rejected";
 650         default: return "???";
 651         }
 652 }
 653
 654 struct ceph_mds_session *ceph_get_mds_session(struct ceph_mds_session *s)
 655 {
 656         if (refcount_inc_not_zero(&s->s_ref))
 657                 return s;
 658         return NULL;
 659 }
 660
 661 void ceph_put_mds_session(struct ceph_mds_session *s)
 662 {
 663         if (IS_ERR_OR_NULL(s))
 664                 return;
 665
 666         if (refcount_dec_and_test(&s->s_ref)) {
 667                 if (s->s_auth.authorizer)
 668                         ceph_auth_destroy_authorizer(s->s_auth.authorizer);
 669                 WARN_ON(mutex_is_locked(&s->s_mutex));
 670                 xa_destroy(&s->s_delegated_inos);
 671                 kfree(s);
 672         }
 673 }
 674
 675 /*
 676  * called under mdsc->mutex
 677  */
 678 struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 679                                                    int mds)
 680 {
 681         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 682                 return NULL;
 683         return ceph_get_mds_session(mdsc->sessions[mds]);
 684 }
 685
 686 static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 687 {
 688         if (mds >= mdsc->max_sessions || !mdsc->sessions[mds])
 689                 return false;
 690         else
 691                 return true;
 692 }
 693
 694 static int __verify_registered_session(struct ceph_mds_client *mdsc,
 695                                        struct ceph_mds_session *s)
 696 {
 697         if (s->s_mds >= mdsc->max_sessions ||
 698             mdsc->sessions[s->s_mds] != s)
 699                 return -ENOENT;
 700         return 0;
 701 }
 702
 703 /*
 704  * create+register a new session for given mds.
 705  * called under mdsc->mutex.
 706  */
 707 static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 708                                                  int mds)
 709 {
 710         struct ceph_mds_session *s;
 711
 712         if (mds >= mdsc->mdsmap->possible_max_rank)
 713                 return ERR_PTR(-EINVAL);
 714
 715         s = kzalloc(sizeof(*s), GFP_NOFS);
 716         if (!s)
 717                 return ERR_PTR(-ENOMEM);
 718
 719         if (mds >= mdsc->max_sessions) {
 720                 int newmax = 1 << get_count_order(mds + 1);
 721                 struct ceph_mds_session **sa;
 722
 723                 dout("%s: realloc to %d\n", __func__, newmax);
 724                 sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 725                 if (!sa)
 726                         goto fail_realloc;
 727                 if (mdsc->sessions) {
 728                         memcpy(sa, mdsc->sessions,
 729                                mdsc->max_sessions * sizeof(void *));
 730                         kfree(mdsc->sessions);
 731                 }
 732                 mdsc->sessions = sa;
 733                 mdsc->max_sessions = newmax;
 734         }
 735
 736         dout("%s: mds%d\n", __func__, mds);
 737         s->s_mdsc = mdsc;
 738         s->s_mds = mds;
 739         s->s_state = CEPH_MDS_SESSION_NEW;
 740         mutex_init(&s->s_mutex);
 741
 742         ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 743
 744         atomic_set(&s->s_cap_gen, 1);
 745         s->s_cap_ttl = jiffies - 1;
 746
 747         spin_lock_init(&s->s_cap_lock);
 748         INIT_LIST_HEAD(&s->s_caps);
 749         refcount_set(&s->s_ref, 1);
 750         INIT_LIST_HEAD(&s->s_waiting);
 751         INIT_LIST_HEAD(&s->s_unsafe);
 752         xa_init(&s->s_delegated_inos);
 753         INIT_LIST_HEAD(&s->s_cap_releases);
 754         INIT_WORK(&s->s_cap_release_work, ceph_cap_release_work);
 755
 756         INIT_LIST_HEAD(&s->s_cap_dirty);
 757         INIT_LIST_HEAD(&s->s_cap_flushing);
 758
 759         mdsc->sessions[mds] = s;
 760         atomic_inc(&mdsc->num_sessions);
 761         refcount_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 762
 763         ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 764                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 765
 766         return s;
 767
 768 fail_realloc:
 769         kfree(s);
 770         return ERR_PTR(-ENOMEM);
 771 }
 772
 773 /*
 774  * called under mdsc->mutex
 775  */
 776 static void __unregister_session(struct ceph_mds_client *mdsc,
 777                                struct ceph_mds_session *s)
 778 {
 779         dout("__unregister_session mds%d %p\n", s->s_mds, s);
 780         BUG_ON(mdsc->sessions[s->s_mds] != s);
 781         mdsc->sessions[s->s_mds] = NULL;
 782         ceph_con_close(&s->s_con);
 783         ceph_put_mds_session(s);
 784         atomic_dec(&mdsc->num_sessions);
 785 }
 786
 787 /*
 788  * drop session refs in request.
 789  *
 790  * should be last request ref, or hold mdsc->mutex
 791  */
 792 static void put_request_session(struct ceph_mds_request *req)
 793 {
 794         if (req->r_session) {
 795                 ceph_put_mds_session(req->r_session);
 796                 req->r_session = NULL;
 797         }
 798 }
 799
 800 void ceph_mdsc_iterate_sessions(struct ceph_mds_client *mdsc,
 801                                 void (*cb)(struct ceph_mds_session *),
 802                                 bool check_state)
 803 {
 804         int mds;
 805
 806         mutex_lock(&mdsc->mutex);
 807         for (mds = 0; mds < mdsc->max_sessions; ++mds) {
 808                 struct ceph_mds_session *s;
 809
 810                 s = __ceph_lookup_mds_session(mdsc, mds);
 811                 if (!s)
 812                         continue;
 813
 814                 if (check_state && !check_session_state(s)) {
 815                         ceph_put_mds_session(s);
 816                         continue;
 817                 }
 818
 819                 mutex_unlock(&mdsc->mutex);
 820                 cb(s);
 821                 ceph_put_mds_session(s);
 822                 mutex_lock(&mdsc->mutex);
 823         }
 824         mutex_unlock(&mdsc->mutex);
 825 }
 826
 827 void ceph_mdsc_release_request(struct kref *kref)
 828 {
 829         struct ceph_mds_request *req = container_of(kref,
 830                                                     struct ceph_mds_request,
 831                                                     r_kref);
 832         ceph_mdsc_release_dir_caps_no_check(req);
 833         destroy_reply_info(&req->r_reply_info);
 834         if (req->r_request)
 835                 ceph_msg_put(req->r_request);
 836         if (req->r_reply)
 837                 ceph_msg_put(req->r_reply);
 838         if (req->r_inode) {
 839                 ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 840                 iput(req->r_inode);
 841         }
 842         if (req->r_parent) {
 843                 ceph_put_cap_refs(ceph_inode(req->r_parent), CEPH_CAP_PIN);
 844                 iput(req->r_parent);
 845         }
 846         iput(req->r_target_inode);
 847         if (req->r_dentry)
 848                 dput(req->r_dentry);
 849         if (req->r_old_dentry)
 850                 dput(req->r_old_dentry);
 851         if (req->r_old_dentry_dir) {
 852                 /*
 853                  * track (and drop pins for) r_old_dentry_dir
 854                  * separately, since r_old_dentry's d_parent may have
 855                  * changed between the dir mutex being dropped and
 856                  * this request being freed.
 857                  */
 858                 ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 859                                   CEPH_CAP_PIN);
 860                 iput(req->r_old_dentry_dir);
 861         }
 862         kfree(req->r_path1);
 863         kfree(req->r_path2);
 864         put_cred(req->r_cred);
 865         if (req->r_pagelist)
 866                 ceph_pagelist_release(req->r_pagelist);
 867         put_request_session(req);
 868         ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 869         WARN_ON_ONCE(!list_empty(&req->r_wait));
 870         kmem_cache_free(ceph_mds_request_cachep, req);
 871 }
 872
 873 DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
 874
 875 /*
 876  * lookup session, bump ref if found.
 877  *
 878  * called under mdsc->mutex.
 879  */
 880 static struct ceph_mds_request *
 881 lookup_get_request(struct ceph_mds_client *mdsc, u64 tid)
 882 {
 883         struct ceph_mds_request *req;
 884
 885         req = lookup_request(&mdsc->request_tree, tid);
 886         if (req)
 887                 ceph_mdsc_get_request(req);
 888
 889         return req;
 890 }
 891
 892 /*
 893  * Register an in-flight request, and assign a tid.  Link to directory
 894  * are modifying (if any).
 895  *
 896  * Called under mdsc->mutex.
 897  */
 898 static void __register_request(struct ceph_mds_client *mdsc,
 899                                struct ceph_mds_request *req,
 900                                struct inode *dir)
 901 {
 902         int ret = 0;
 903
 904         req->r_tid = ++mdsc->last_tid;
 905         if (req->r_num_caps) {
 906                 ret = ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 907                                         req->r_num_caps);
 908                 if (ret < 0) {
 909                         pr_err("__register_request %p "
 910                                "failed to reserve caps: %d\n", req, ret);
 911                         /* set req->r_err to fail early from __do_request */
 912                         req->r_err = ret;
 913                         return;
 914                 }
 915         }
 916         dout("__register_request %p tid %lld\n", req, req->r_tid);
 917         ceph_mdsc_get_request(req);
 918         insert_request(&mdsc->request_tree, req);
 919
 920         req->r_cred = get_current_cred();
 921
 922         if (mdsc->oldest_tid == 0 && req->r_op != CEPH_MDS_OP_SETFILELOCK)
 923                 mdsc->oldest_tid = req->r_tid;
 924
 925         if (dir) {
 926                 struct ceph_inode_info *ci = ceph_inode(dir);
 927
 928                 ihold(dir);
 929                 req->r_unsafe_dir = dir;
 930                 spin_lock(&ci->i_unsafe_lock);
 931                 list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 932                 spin_unlock(&ci->i_unsafe_lock);
 933         }
 934 }
 935
 936 static void __unregister_request(struct ceph_mds_client *mdsc,
 937                                  struct ceph_mds_request *req)
 938 {
 939         dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 940
 941         /* Never leave an unregistered request on an unsafe list! */
 942         list_del_init(&req->r_unsafe_item);
 943
 944         if (req->r_tid == mdsc->oldest_tid) {
 945                 struct rb_node *p = rb_next(&req->r_node);
 946                 mdsc->oldest_tid = 0;
 947                 while (p) {
 948                         struct ceph_mds_request *next_req =
 949                                 rb_entry(p, struct ceph_mds_request, r_node);
 950                         if (next_req->r_op != CEPH_MDS_OP_SETFILELOCK) {
 951                                 mdsc->oldest_tid = next_req->r_tid;
 952                                 break;
 953                         }
 954                         p = rb_next(p);
 955                 }
 956         }
 957
 958         erase_request(&mdsc->request_tree, req);
 959
 960         if (req->r_unsafe_dir) {
 961                 struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 962                 spin_lock(&ci->i_unsafe_lock);
 963                 list_del_init(&req->r_unsafe_dir_item);
 964                 spin_unlock(&ci->i_unsafe_lock);
 965         }
 966         if (req->r_target_inode &&
 967             test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 968                 struct ceph_inode_info *ci = ceph_inode(req->r_target_inode);
 969                 spin_lock(&ci->i_unsafe_lock);
 970                 list_del_init(&req->r_unsafe_target_item);
 971                 spin_unlock(&ci->i_unsafe_lock);
 972         }
 973
 974         if (req->r_unsafe_dir) {
 975                 iput(req->r_unsafe_dir);
 976                 req->r_unsafe_dir = NULL;
 977         }
 978
 979         complete_all(&req->r_safe_completion);
 980
 981         ceph_mdsc_put_request(req);
 982 }
 983
 984 /*
 985  * Walk back up the dentry tree until we hit a dentry representing a
 986  * non-snapshot inode. We do this using the rcu_read_lock (which must be held
 987  * when calling this) to ensure that the objects won't disappear while we're
 988  * working with them. Once we hit a candidate dentry, we attempt to take a
 989  * reference to it, and return that as the result.
 990  */
 991 static struct inode *get_nonsnap_parent(struct dentry *dentry)
 992 {
 993         struct inode *inode = NULL;
 994
 995         while (dentry && !IS_ROOT(dentry)) {
 996                 inode = d_inode_rcu(dentry);
 997                 if (!inode || ceph_snap(inode) == CEPH_NOSNAP)
 998                         break;
 999                 dentry = dentry->d_parent;
1000         }
1001         if (inode)
1002                 inode = igrab(inode);
1003         return inode;
1004 }
1005
1006 /*
1007  * Choose mds to send request to next.  If there is a hint set in the
1008  * request (e.g., due to a prior forward hint from the mds), use that.
1009  * Otherwise, consult frag tree and/or caps to identify the
1010  * appropriate mds.  If all else fails, choose randomly.
1011  *
1012  * Called under mdsc->mutex.
1013  */
1014 static int __choose_mds(struct ceph_mds_client *mdsc,
1015                         struct ceph_mds_request *req,
1016                         bool *random)
1017 {
1018         struct inode *inode;
1019         struct ceph_inode_info *ci;
1020         struct ceph_cap *cap;
1021         int mode = req->r_direct_mode;
1022         int mds = -1;
1023         u32 hash = req->r_direct_hash;
1024         bool is_hash = test_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
1025
1026         if (random)
1027                 *random = false;
1028
1029         /*
1030          * is there a specific mds we should try?  ignore hint if we have
1031          * no session and the mds is not up (active or recovering).
1032          */
1033         if (req->r_resend_mds >= 0 &&
1034             (__have_session(mdsc, req->r_resend_mds) ||
1035              ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
1036                 dout("%s using resend_mds mds%d\n", __func__,
1037                      req->r_resend_mds);
1038                 return req->r_resend_mds;
1039         }
1040
1041         if (mode == USE_RANDOM_MDS)
1042                 goto random;
1043
1044         inode = NULL;
1045         if (req->r_inode) {
1046                 if (ceph_snap(req->r_inode) != CEPH_SNAPDIR) {
1047                         inode = req->r_inode;
1048                         ihold(inode);
1049                 } else {
1050                         /* req->r_dentry is non-null for LSSNAP request */
1051                         rcu_read_lock();
1052                         inode = get_nonsnap_parent(req->r_dentry);
1053                         rcu_read_unlock();
1054                         dout("%s using snapdir's parent %p\n", __func__, inode);
1055                 }
1056         } else if (req->r_dentry) {
1057                 /* ignore race with rename; old or new d_parent is okay */
1058                 struct dentry *parent;
1059                 struct inode *dir;
1060
1061                 rcu_read_lock();
1062                 parent = READ_ONCE(req->r_dentry->d_parent);
1063                 dir = req->r_parent ? : d_inode_rcu(parent);
1064
1065                 if (!dir || dir->i_sb != mdsc->fsc->sb) {
1066                         /*  not this fs or parent went negative */
1067                         inode = d_inode(req->r_dentry);
1068                         if (inode)
1069                                 ihold(inode);
1070                 } else if (ceph_snap(dir) != CEPH_NOSNAP) {
1071                         /* direct snapped/virtual snapdir requests
1072                          * based on parent dir inode */
1073                         inode = get_nonsnap_parent(parent);
1074                         dout("%s using nonsnap parent %p\n", __func__, inode);
1075                 } else {
1076                         /* dentry target */
1077                         inode = d_inode(req->r_dentry);
1078                         if (!inode || mode == USE_AUTH_MDS) {
1079                                 /* dir + name */
1080                                 inode = igrab(dir);
1081                                 hash = ceph_dentry_hash(dir, req->r_dentry);
1082                                 is_hash = true;
1083                         } else {
1084                                 ihold(inode);
1085                         }
1086                 }
1087                 rcu_read_unlock();
1088         }
1089
1090         dout("%s %p is_hash=%d (0x%x) mode %d\n", __func__, inode, (int)is_hash,
1091              hash, mode);
1092         if (!inode)
1093                 goto random;
1094         ci = ceph_inode(inode);
1095
1096         if (is_hash && S_ISDIR(inode->i_mode)) {
1097                 struct ceph_inode_frag frag;
1098                 int found;
1099
1100                 ceph_choose_frag(ci, hash, &frag, &found);
1101                 if (found) {
1102                         if (mode == USE_ANY_MDS && frag.ndist > 0) {
1103                                 u8 r;
1104
1105                                 /* choose a random replica */
1106                                 get_random_bytes(&r, 1);
1107                                 r %= frag.ndist;
1108                                 mds = frag.dist[r];
1109                                 dout("%s %p %llx.%llx frag %u mds%d (%d/%d)\n",
1110                                      __func__, inode, ceph_vinop(inode),
1111                                      frag.frag, mds, (int)r, frag.ndist);
1112                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
1113                                     CEPH_MDS_STATE_ACTIVE &&
1114                                     !ceph_mdsmap_is_laggy(mdsc->mdsmap, mds))
1115                                         goto out;
1116                         }
1117
1118                         /* since this file/dir wasn't known to be
1119                          * replicated, then we want to look for the
1120                          * authoritative mds. */
1121                         if (frag.mds >= 0) {
1122                                 /* choose auth mds */
1123                                 mds = frag.mds;
1124                                 dout("%s %p %llx.%llx frag %u mds%d (auth)\n",
1125                                      __func__, inode, ceph_vinop(inode),
1126                                      frag.frag, mds);
1127                                 if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
1128                                     CEPH_MDS_STATE_ACTIVE) {
1129                                         if (!ceph_mdsmap_is_laggy(mdsc->mdsmap,
1130                                                                   mds))
1131                                                 goto out;
1132                                 }
1133                         }
1134                         mode = USE_AUTH_MDS;
1135                 }
1136         }
1137
1138         spin_lock(&ci->i_ceph_lock);
1139         cap = NULL;
1140         if (mode == USE_AUTH_MDS)
1141                 cap = ci->i_auth_cap;
1142         if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
1143                 cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
1144         if (!cap) {
1145                 spin_unlock(&ci->i_ceph_lock);
1146                 iput(inode);
1147                 goto random;
1148         }
1149         mds = cap->session->s_mds;
1150         dout("%s %p %llx.%llx mds%d (%scap %p)\n", __func__,
1151              inode, ceph_vinop(inode), mds,
1152              cap == ci->i_auth_cap ? "auth " : "", cap);
1153         spin_unlock(&ci->i_ceph_lock);
1154 out:
1155         iput(inode);
1156         return mds;
1157
1158 random:
1159         if (random)
1160                 *random = true;
1161
1162         mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
1163         dout("%s chose random mds%d\n", __func__, mds);
1164         return mds;
1165 }
1166
1167
1168 /*
1169  * session messages
1170  */
1171 struct ceph_msg *ceph_create_session_msg(u32 op, u64 seq)
1172 {
1173         struct ceph_msg *msg;
1174         struct ceph_mds_session_head *h;
1175
1176         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
1177                            false);
1178         if (!msg) {
1179                 pr_err("ENOMEM creating session %s msg\n",
1180                        ceph_session_op_name(op));
1181                 return NULL;
1182         }
1183         h = msg->front.iov_base;
1184         h->op = cpu_to_le32(op);
1185         h->seq = cpu_to_le64(seq);
1186
1187         return msg;
1188 }
1189
1190 static const unsigned char feature_bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
1191 #define FEATURE_BYTES(c) (DIV_ROUND_UP((size_t)feature_bits[c - 1] + 1, 64) * 8)
1192 static int encode_supported_features(void **p, void *end)
1193 {
1194         static const size_t count = ARRAY_SIZE(feature_bits);
1195
1196         if (count > 0) {
1197                 size_t i;
1198                 size_t size = FEATURE_BYTES(count);
1199
1200                 if (WARN_ON_ONCE(*p + 4 + size > end))
1201                         return -ERANGE;
1202
1203                 ceph_encode_32(p, size);
1204                 memset(*p, 0, size);
1205                 for (i = 0; i < count; i++)
1206                         ((unsigned char*)(*p))[i / 8] |= BIT(feature_bits[i] % 8);
1207                 *p += size;
1208         } else {
1209                 if (WARN_ON_ONCE(*p + 4 > end))
1210                         return -ERANGE;
1211
1212                 ceph_encode_32(p, 0);
1213         }
1214
1215         return 0;
1216 }
1217
1218 static const unsigned char metric_bits[] = CEPHFS_METRIC_SPEC_CLIENT_SUPPORTED;
1219 #define METRIC_BYTES(cnt) (DIV_ROUND_UP((size_t)metric_bits[cnt - 1] + 1, 64) * 8)
1220 static int encode_metric_spec(void **p, void *end)
1221 {
1222         static const size_t count = ARRAY_SIZE(metric_bits);
1223
1224         /* header */
1225         if (WARN_ON_ONCE(*p + 2 > end))
1226                 return -ERANGE;
1227
1228         ceph_encode_8(p, 1); /* version */
1229         ceph_encode_8(p, 1); /* compat */
1230
1231         if (count > 0) {
1232                 size_t i;
1233                 size_t size = METRIC_BYTES(count);
1234
1235                 if (WARN_ON_ONCE(*p + 4 + 4 + size > end))
1236                         return -ERANGE;
1237
1238                 /* metric spec info length */
1239                 ceph_encode_32(p, 4 + size);
1240
1241                 /* metric spec */
1242                 ceph_encode_32(p, size);
1243                 memset(*p, 0, size);
1244                 for (i = 0; i < count; i++)
1245                         ((unsigned char *)(*p))[i / 8] |= BIT(metric_bits[i] % 8);
1246                 *p += size;
1247         } else {
1248                 if (WARN_ON_ONCE(*p + 4 + 4 > end))
1249                         return -ERANGE;
1250
1251                 /* metric spec info length */
1252                 ceph_encode_32(p, 4);
1253                 /* metric spec */
1254                 ceph_encode_32(p, 0);
1255         }
1256
1257         return 0;
1258 }
1259
1260 /*
1261  * session message, specialization for CEPH_SESSION_REQUEST_OPEN
1262  * to include additional client metadata fields.
1263  */
1264 static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u64 seq)
1265 {
1266         struct ceph_msg *msg;
1267         struct ceph_mds_session_head *h;
1268         int i;
1269         int extra_bytes = 0;
1270         int metadata_key_count = 0;
1271         struct ceph_options *opt = mdsc->fsc->client->options;
1272         struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
1273         size_t size, count;
1274         void *p, *end;
1275         int ret;
1276
1277         const char* metadata[][2] = {
1278                 {"hostname", mdsc->nodename},
1279                 {"kernel_version", init_utsname()->release},
1280                 {"entity_id", opt->name ? : ""},
1281                 {"root", fsopt->server_path ? : "/"},
1282                 {NULL, NULL}
1283         };
1284
1285         /* Calculate serialized length of metadata */
1286         extra_bytes = 4;  /* map length */
1287         for (i = 0; metadata[i][0]; ++i) {
1288                 extra_bytes += 8 + strlen(metadata[i][0]) +
1289                         strlen(metadata[i][1]);
1290                 metadata_key_count++;
1291         }
1292
1293         /* supported feature */
1294         size = 0;
1295         count = ARRAY_SIZE(feature_bits);
1296         if (count > 0)
1297                 size = FEATURE_BYTES(count);
1298         extra_bytes += 4 + size;
1299
1300         /* metric spec */
1301         size = 0;
1302         count = ARRAY_SIZE(metric_bits);
1303         if (count > 0)
1304                 size = METRIC_BYTES(count);
1305         extra_bytes += 2 + 4 + 4 + size;
1306
1307         /* Allocate the message */
1308         msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h) + extra_bytes,
1309                            GFP_NOFS, false);
1310         if (!msg) {
1311                 pr_err("ENOMEM creating session open msg\n");
1312                 return ERR_PTR(-ENOMEM);
1313         }
1314         p = msg->front.iov_base;
1315         end = p + msg->front.iov_len;
1316
1317         h = p;
1318         h->op = cpu_to_le32(CEPH_SESSION_REQUEST_OPEN);
1319         h->seq = cpu_to_le64(seq);
1320
1321         /*
1322          * Serialize client metadata into waiting buffer space, using
1323          * the format that userspace expects for map<string, string>
1324          *
1325          * ClientSession messages with metadata are v4
1326          */
1327         msg->hdr.version = cpu_to_le16(4);
1328         msg->hdr.compat_version = cpu_to_le16(1);
1329
1330         /* The write pointer, following the session_head structure */
1331         p += sizeof(*h);
1332
1333         /* Number of entries in the map */
1334         ceph_encode_32(&p, metadata_key_count);
1335
1336         /* Two length-prefixed strings for each entry in the map */
1337         for (i = 0; metadata[i][0]; ++i) {
1338                 size_t const key_len = strlen(metadata[i][0]);
1339                 size_t const val_len = strlen(metadata[i][1]);
1340
1341                 ceph_encode_32(&p, key_len);
1342                 memcpy(p, metadata[i][0], key_len);
1343                 p += key_len;
1344                 ceph_encode_32(&p, val_len);
1345                 memcpy(p, metadata[i][1], val_len);
1346                 p += val_len;
1347         }
1348
1349         ret = encode_supported_features(&p, end);
1350         if (ret) {
1351                 pr_err("encode_supported_features failed!\n");
1352                 ceph_msg_put(msg);
1353                 return ERR_PTR(ret);
1354         }
1355
1356         ret = encode_metric_spec(&p, end);
1357         if (ret) {
1358                 pr_err("encode_metric_spec failed!\n");
1359                 ceph_msg_put(msg);
1360                 return ERR_PTR(ret);
1361         }
1362
1363         msg->front.iov_len = p - msg->front.iov_base;
1364         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1365
1366         return msg;
1367 }
1368
1369 /*
1370  * send session open request.
1371  *
1372  * called under mdsc->mutex
1373  */
1374 static int __open_session(struct ceph_mds_client *mdsc,
1375                           struct ceph_mds_session *session)
1376 {
1377         struct ceph_msg *msg;
1378         int mstate;
1379         int mds = session->s_mds;
1380
1381         /* wait for mds to go active? */
1382         mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
1383         dout("open_session to mds%d (%s)\n", mds,
1384              ceph_mds_state_name(mstate));
1385         session->s_state = CEPH_MDS_SESSION_OPENING;
1386         session->s_renew_requested = jiffies;
1387
1388         /* send connect message */
1389         msg = create_session_open_msg(mdsc, session->s_seq);
1390         if (IS_ERR(msg))
1391                 return PTR_ERR(msg);
1392         ceph_con_send(&session->s_con, msg);
1393         return 0;
1394 }
1395
1396 /*
1397  * open sessions for any export targets for the given mds
1398  *
1399  * called under mdsc->mutex
1400  */
1401 static struct ceph_mds_session *
1402 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
1403 {
1404         struct ceph_mds_session *session;
1405         int ret;
1406
1407         session = __ceph_lookup_mds_session(mdsc, target);
1408         if (!session) {
1409                 session = register_session(mdsc, target);
1410                 if (IS_ERR(session))
1411                         return session;
1412         }
1413         if (session->s_state == CEPH_MDS_SESSION_NEW ||
1414             session->s_state == CEPH_MDS_SESSION_CLOSING) {
1415                 ret = __open_session(mdsc, session);
1416                 if (ret)
1417                         return ERR_PTR(ret);
1418         }
1419
1420         return session;
1421 }
1422
1423 struct ceph_mds_session *
1424 ceph_mdsc_open_export_target_session(struct ceph_mds_client *mdsc, int target)
1425 {
1426         struct ceph_mds_session *session;
1427
1428         dout("open_export_target_session to mds%d\n", target);
1429
1430         mutex_lock(&mdsc->mutex);
1431         session = __open_export_target_session(mdsc, target);
1432         mutex_unlock(&mdsc->mutex);
1433
1434         return session;
1435 }
1436
1437 static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
1438                                           struct ceph_mds_session *session)
1439 {
1440         struct ceph_mds_info *mi;
1441         struct ceph_mds_session *ts;
1442         int i, mds = session->s_mds;
1443
1444         if (mds >= mdsc->mdsmap->possible_max_rank)
1445                 return;
1446
1447         mi = &mdsc->mdsmap->m_info[mds];
1448         dout("open_export_target_sessions for mds%d (%d targets)\n",
1449              session->s_mds, mi->num_export_targets);
1450
1451         for (i = 0; i < mi->num_export_targets; i++) {
1452                 ts = __open_export_target_session(mdsc, mi->export_targets[i]);
1453                 ceph_put_mds_session(ts);
1454         }
1455 }
1456
1457 void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
1458                                            struct ceph_mds_session *session)
1459 {
1460         mutex_lock(&mdsc->mutex);
1461         __open_export_target_sessions(mdsc, session);
1462         mutex_unlock(&mdsc->mutex);
1463 }
1464
1465 /*
1466  * session caps
1467  */
1468
1469 static void detach_cap_releases(struct ceph_mds_session *session,
1470                                 struct list_head *target)
1471 {
1472         lockdep_assert_held(&session->s_cap_lock);
1473
1474         list_splice_init(&session->s_cap_releases, target);
1475         session->s_num_cap_releases = 0;
1476         dout("dispose_cap_releases mds%d\n", session->s_mds);
1477 }
1478
1479 static void dispose_cap_releases(struct ceph_mds_client *mdsc,
1480                                  struct list_head *dispose)
1481 {
1482         while (!list_empty(dispose)) {
1483                 struct ceph_cap *cap;
1484                 /* zero out the in-progress message */
1485                 cap = list_first_entry(dispose, struct ceph_cap, session_caps);
1486                 list_del(&cap->session_caps);
1487                 ceph_put_cap(mdsc, cap);
1488         }
1489 }
1490
1491 static void cleanup_session_requests(struct ceph_mds_client *mdsc,
1492                                      struct ceph_mds_session *session)
1493 {
1494         struct ceph_mds_request *req;
1495         struct rb_node *p;
1496
1497         dout("cleanup_session_requests mds%d\n", session->s_mds);
1498         mutex_lock(&mdsc->mutex);
1499         while (!list_empty(&session->s_unsafe)) {
1500                 req = list_first_entry(&session->s_unsafe,
1501                                        struct ceph_mds_request, r_unsafe_item);
1502                 pr_warn_ratelimited(" dropping unsafe request %llu\n",
1503                                     req->r_tid);
1504                 if (req->r_target_inode)
1505                         mapping_set_error(req->r_target_inode->i_mapping, -EIO);
1506                 if (req->r_unsafe_dir)
1507                         mapping_set_error(req->r_unsafe_dir->i_mapping, -EIO);
1508                 __unregister_request(mdsc, req);
1509         }
1510         /* zero r_attempts, so kick_requests() will re-send requests */
1511         p = rb_first(&mdsc->request_tree);
1512         while (p) {
1513                 req = rb_entry(p, struct ceph_mds_request, r_node);
1514                 p = rb_next(p);
1515                 if (req->r_session &&
1516                     req->r_session->s_mds == session->s_mds)
1517                         req->r_attempts = 0;
1518         }
1519         mutex_unlock(&mdsc->mutex);
1520 }
1521
1522 /*
1523  * Helper to safely iterate over all caps associated with a session, with
1524  * special care taken to handle a racing __ceph_remove_cap().
1525  *
1526  * Caller must hold session s_mutex.
1527  */
1528 int ceph_iterate_session_caps(struct ceph_mds_session *session,
1529                               int (*cb)(struct inode *, struct ceph_cap *,
1530                                         void *), void *arg)
1531 {
1532         struct list_head *p;
1533         struct ceph_cap *cap;
1534         struct inode *inode, *last_inode = NULL;
1535         struct ceph_cap *old_cap = NULL;
1536         int ret;
1537
1538         dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
1539         spin_lock(&session->s_cap_lock);
1540         p = session->s_caps.next;
1541         while (p != &session->s_caps) {
1542                 cap = list_entry(p, struct ceph_cap, session_caps);
1543                 inode = igrab(&cap->ci->vfs_inode);
1544                 if (!inode) {
1545                         p = p->next;
1546                         continue;
1547                 }
1548                 session->s_cap_iterator = cap;
1549                 spin_unlock(&session->s_cap_lock);
1550
1551                 if (last_inode) {
1552                         iput(last_inode);
1553                         last_inode = NULL;
1554                 }
1555                 if (old_cap) {
1556                         ceph_put_cap(session->s_mdsc, old_cap);
1557                         old_cap = NULL;
1558                 }
1559
1560                 ret = cb(inode, cap, arg);
1561                 last_inode = inode;
1562
1563                 spin_lock(&session->s_cap_lock);
1564                 p = p->next;
1565                 if (!cap->ci) {
1566                         dout("iterate_session_caps  finishing cap %p removal\n",
1567                              cap);
1568                         BUG_ON(cap->session != session);
1569                         cap->session = NULL;
1570                         list_del_init(&cap->session_caps);
1571                         session->s_nr_caps--;
1572                         atomic64_dec(&session->s_mdsc->metric.total_caps);
1573                         if (cap->queue_release)
1574                                 __ceph_queue_cap_release(session, cap);
1575                         else
1576                                 old_cap = cap;  /* put_cap it w/o locks held */
1577                 }
1578                 if (ret < 0)
1579                         goto out;
1580         }
1581         ret = 0;
1582 out:
1583         session->s_cap_iterator = NULL;
1584         spin_unlock(&session->s_cap_lock);
1585
1586         iput(last_inode);
1587         if (old_cap)
1588                 ceph_put_cap(session->s_mdsc, old_cap);
1589
1590         return ret;
1591 }
1592
1593 static int remove_capsnaps(struct ceph_mds_client *mdsc, struct inode *inode)
1594 {
1595         struct ceph_inode_info *ci = ceph_inode(inode);
1596         struct ceph_cap_snap *capsnap;
1597         int capsnap_release = 0;
1598
1599         lockdep_assert_held(&ci->i_ceph_lock);
1600
1601         dout("removing capsnaps, ci is %p, inode is %p\n", ci, inode);
1602
1603         while (!list_empty(&ci->i_cap_snaps)) {
1604                 capsnap = list_first_entry(&ci->i_cap_snaps,
1605                                            struct ceph_cap_snap, ci_item);
1606                 __ceph_remove_capsnap(inode, capsnap, NULL, NULL);
1607                 ceph_put_snap_context(capsnap->context);
1608                 ceph_put_cap_snap(capsnap);
1609                 capsnap_release++;
1610         }
1611         wake_up_all(&ci->i_cap_wq);
1612         wake_up_all(&mdsc->cap_flushing_wq);
1613         return capsnap_release;
1614 }
1615
1616 static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
1617                                   void *arg)
1618 {
1619         struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
1620         struct ceph_mds_client *mdsc = fsc->mdsc;
1621         struct ceph_inode_info *ci = ceph_inode(inode);
1622         LIST_HEAD(to_remove);
1623         bool dirty_dropped = false;
1624         bool invalidate = false;
1625         int capsnap_release = 0;
1626
1627         dout("removing cap %p, ci is %p, inode is %p\n",
1628              cap, ci, &ci->vfs_inode);
1629         spin_lock(&ci->i_ceph_lock);
1630         __ceph_remove_cap(cap, false);
1631         if (!ci->i_auth_cap) {
1632                 struct ceph_cap_flush *cf;
1633
1634                 if (READ_ONCE(fsc->mount_state) >= CEPH_MOUNT_SHUTDOWN) {
1635                         if (inode->i_data.nrpages > 0)
1636                                 invalidate = true;
1637                         if (ci->i_wrbuffer_ref > 0)
1638                                 mapping_set_error(&inode->i_data, -EIO);
1639                 }
1640
1641                 while (!list_empty(&ci->i_cap_flush_list)) {
1642                         cf = list_first_entry(&ci->i_cap_flush_list,
1643                                               struct ceph_cap_flush, i_list);
1644                         list_move(&cf->i_list, &to_remove);
1645                 }
1646
1647                 spin_lock(&mdsc->cap_dirty_lock);
1648
1649                 list_for_each_entry(cf, &to_remove, i_list)
1650                         list_del_init(&cf->g_list);
1651
1652                 if (!list_empty(&ci->i_dirty_item)) {
1653                         pr_warn_ratelimited(
1654                                 " dropping dirty %s state for %p %lld\n",
1655                                 ceph_cap_string(ci->i_dirty_caps),
1656                                 inode, ceph_ino(inode));
1657                         ci->i_dirty_caps = 0;
1658                         list_del_init(&ci->i_dirty_item);
1659                         dirty_dropped = true;
1660                 }
1661                 if (!list_empty(&ci->i_flushing_item)) {
1662                         pr_warn_ratelimited(
1663                                 " dropping dirty+flushing %s state for %p %lld\n",
1664                                 ceph_cap_string(ci->i_flushing_caps),
1665                                 inode, ceph_ino(inode));
1666                         ci->i_flushing_caps = 0;
1667                         list_del_init(&ci->i_flushing_item);
1668                         mdsc->num_cap_flushing--;
1669                         dirty_dropped = true;
1670                 }
1671                 spin_unlock(&mdsc->cap_dirty_lock);
1672
1673                 if (dirty_dropped) {
1674                         mapping_set_error(inode->i_mapping, -EIO);
1675
1676                         if (ci->i_wrbuffer_ref_head == 0 &&
1677                             ci->i_wr_ref == 0 &&
1678                             ci->i_dirty_caps == 0 &&
1679                             ci->i_flushing_caps == 0) {
1680                                 ceph_put_snap_context(ci->i_head_snapc);
1681                                 ci->i_head_snapc = NULL;
1682                         }
1683                 }
1684
1685                 if (atomic_read(&ci->i_filelock_ref) > 0) {
1686                         /* make further file lock syscall return -EIO */
1687                         ci->i_ceph_flags |= CEPH_I_ERROR_FILELOCK;
1688                         pr_warn_ratelimited(" dropping file locks for %p %lld\n",
1689                                             inode, ceph_ino(inode));
1690                 }
1691
1692                 if (!ci->i_dirty_caps && ci->i_prealloc_cap_flush) {
1693                         list_add(&ci->i_prealloc_cap_flush->i_list, &to_remove);
1694                         ci->i_prealloc_cap_flush = NULL;
1695                 }
1696
1697                 if (!list_empty(&ci->i_cap_snaps))
1698                         capsnap_release = remove_capsnaps(mdsc, inode);
1699         }
1700         spin_unlock(&ci->i_ceph_lock);
1701         while (!list_empty(&to_remove)) {
1702                 struct ceph_cap_flush *cf;
1703                 cf = list_first_entry(&to_remove,
1704                                       struct ceph_cap_flush, i_list);
1705                 list_del_init(&cf->i_list);
1706                 if (!cf->is_capsnap)
1707                         ceph_free_cap_flush(cf);
1708         }
1709
1710         wake_up_all(&ci->i_cap_wq);
1711         if (invalidate)
1712                 ceph_queue_invalidate(inode);
1713         if (dirty_dropped)
1714                 iput(inode);
1715         while (capsnap_release--)
1716                 iput(inode);
1717         return 0;
1718 }
1719
1720 /*
1721  * caller must hold session s_mutex
1722  */
1723 static void remove_session_caps(struct ceph_mds_session *session)
1724 {
1725         struct ceph_fs_client *fsc = session->s_mdsc->fsc;
1726         struct super_block *sb = fsc->sb;
1727         LIST_HEAD(dispose);
1728
1729         dout("remove_session_caps on %p\n", session);
1730         ceph_iterate_session_caps(session, remove_session_caps_cb, fsc);
1731
1732         wake_up_all(&fsc->mdsc->cap_flushing_wq);
1733
1734         spin_lock(&session->s_cap_lock);
1735         if (session->s_nr_caps > 0) {
1736                 struct inode *inode;
1737                 struct ceph_cap *cap, *prev = NULL;
1738                 struct ceph_vino vino;
1739                 /*
1740                  * iterate_session_caps() skips inodes that are being
1741                  * deleted, we need to wait until deletions are complete.
1742                  * __wait_on_freeing_inode() is designed for the job,
1743                  * but it is not exported, so use lookup inode function
1744                  * to access it.
1745                  */
1746                 while (!list_empty(&session->s_caps)) {
1747                         cap = list_entry(session->s_caps.next,
1748                                          struct ceph_cap, session_caps);
1749                         if (cap == prev)
1750                                 break;
1751                         prev = cap;
1752                         vino = cap->ci->i_vino;
1753                         spin_unlock(&session->s_cap_lock);
1754
1755                         inode = ceph_find_inode(sb, vino);
1756                         iput(inode);
1757
1758                         spin_lock(&session->s_cap_lock);
1759                 }
1760         }
1761
1762         // drop cap expires and unlock s_cap_lock
1763         detach_cap_releases(session, &dispose);
1764
1765         BUG_ON(session->s_nr_caps > 0);
1766         BUG_ON(!list_empty(&session->s_cap_flushing));
1767         spin_unlock(&session->s_cap_lock);
1768         dispose_cap_releases(session->s_mdsc, &dispose);
1769 }
1770
1771 enum {
1772         RECONNECT,
1773         RENEWCAPS,
1774         FORCE_RO,
1775 };
1776
1777 /*
1778  * wake up any threads waiting on this session's caps.  if the cap is
1779  * old (didn't get renewed on the client reconnect), remove it now.
1780  *
1781  * caller must hold s_mutex.
1782  */
1783 static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1784                               void *arg)
1785 {
1786         struct ceph_inode_info *ci = ceph_inode(inode);
1787         unsigned long ev = (unsigned long)arg;
1788
1789         if (ev == RECONNECT) {
1790                 spin_lock(&ci->i_ceph_lock);
1791                 ci->i_wanted_max_size = 0;
1792                 ci->i_requested_max_size = 0;
1793                 spin_unlock(&ci->i_ceph_lock);
1794         } else if (ev == RENEWCAPS) {
1795                 if (cap->cap_gen < atomic_read(&cap->session->s_cap_gen)) {
1796                         /* mds did not re-issue stale cap */
1797                         spin_lock(&ci->i_ceph_lock);
1798                         cap->issued = cap->implemented = CEPH_CAP_PIN;
1799                         spin_unlock(&ci->i_ceph_lock);
1800                 }
1801         } else if (ev == FORCE_RO) {
1802         }
1803         wake_up_all(&ci->i_cap_wq);
1804         return 0;
1805 }
1806
1807 static void wake_up_session_caps(struct ceph_mds_session *session, int ev)
1808 {
1809         dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1810         ceph_iterate_session_caps(session, wake_up_session_cb,
1811                                   (void *)(unsigned long)ev);
1812 }
1813
1814 /*
1815  * Send periodic message to MDS renewing all currently held caps.  The
1816  * ack will reset the expiration for all caps from this session.
1817  *
1818  * caller holds s_mutex
1819  */
1820 static int send_renew_caps(struct ceph_mds_client *mdsc,
1821                            struct ceph_mds_session *session)
1822 {
1823         struct ceph_msg *msg;
1824         int state;
1825
1826         if (time_after_eq(jiffies, session->s_cap_ttl) &&
1827             time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1828                 pr_info("mds%d caps stale\n", session->s_mds);
1829         session->s_renew_requested = jiffies;
1830
1831         /* do not try to renew caps until a recovering mds has reconnected
1832          * with its clients. */
1833         state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1834         if (state < CEPH_MDS_STATE_RECONNECT) {
1835                 dout("send_renew_caps ignoring mds%d (%s)\n",
1836                      session->s_mds, ceph_mds_state_name(state));
1837                 return 0;
1838         }
1839
1840         dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1841                 ceph_mds_state_name(state));
1842         msg = ceph_create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1843                                       ++session->s_renew_seq);
1844         if (!msg)
1845                 return -ENOMEM;
1846         ceph_con_send(&session->s_con, msg);
1847         return 0;
1848 }
1849
1850 static int send_flushmsg_ack(struct ceph_mds_client *mdsc,
1851                              struct ceph_mds_session *session, u64 seq)
1852 {
1853         struct ceph_msg *msg;
1854
1855         dout("send_flushmsg_ack to mds%d (%s)s seq %lld\n",
1856              session->s_mds, ceph_session_state_name(session->s_state), seq);
1857         msg = ceph_create_session_msg(CEPH_SESSION_FLUSHMSG_ACK, seq);
1858         if (!msg)
1859                 return -ENOMEM;
1860         ceph_con_send(&session->s_con, msg);
1861         return 0;
1862 }
1863
1864
1865 /*
1866  * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1867  *
1868  * Called under session->s_mutex
1869  */
1870 static void renewed_caps(struct ceph_mds_client *mdsc,
1871                          struct ceph_mds_session *session, int is_renew)
1872 {
1873         int was_stale;
1874         int wake = 0;
1875
1876         spin_lock(&session->s_cap_lock);
1877         was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1878
1879         session->s_cap_ttl = session->s_renew_requested +
1880                 mdsc->mdsmap->m_session_timeout*HZ;
1881
1882         if (was_stale) {
1883                 if (time_before(jiffies, session->s_cap_ttl)) {
1884                         pr_info("mds%d caps renewed\n", session->s_mds);
1885                         wake = 1;
1886                 } else {
1887                         pr_info("mds%d caps still stale\n", session->s_mds);
1888                 }
1889         }
1890         dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1891              session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1892              time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1893         spin_unlock(&session->s_cap_lock);
1894
1895         if (wake)
1896                 wake_up_session_caps(session, RENEWCAPS);
1897 }
1898
1899 /*
1900  * send a session close request
1901  */
1902 static int request_close_session(struct ceph_mds_session *session)
1903 {
1904         struct ceph_msg *msg;
1905
1906         dout("request_close_session mds%d state %s seq %lld\n",
1907              session->s_mds, ceph_session_state_name(session->s_state),
1908              session->s_seq);
1909         msg = ceph_create_session_msg(CEPH_SESSION_REQUEST_CLOSE,
1910                                       session->s_seq);
1911         if (!msg)
1912                 return -ENOMEM;
1913         ceph_con_send(&session->s_con, msg);
1914         return 1;
1915 }
1916
1917 /*
1918  * Called with s_mutex held.
1919  */
1920 static int __close_session(struct ceph_mds_client *mdsc,
1921                          struct ceph_mds_session *session)
1922 {
1923         if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1924                 return 0;
1925         session->s_state = CEPH_MDS_SESSION_CLOSING;
1926         return request_close_session(session);
1927 }
1928
1929 static bool drop_negative_children(struct dentry *dentry)
1930 {
1931         struct dentry *child;
1932         bool all_negative = true;
1933
1934         if (!d_is_dir(dentry))
1935                 goto out;
1936
1937         spin_lock(&dentry->d_lock);
1938         list_for_each_entry(child, &dentry->d_subdirs, d_child) {
1939                 if (d_really_is_positive(child)) {
1940                         all_negative = false;
1941                         break;
1942                 }
1943         }
1944         spin_unlock(&dentry->d_lock);
1945
1946         if (all_negative)
1947                 shrink_dcache_parent(dentry);
1948 out:
1949         return all_negative;
1950 }
1951
1952 /*
1953  * Trim old(er) caps.
1954  *
1955  * Because we can't cache an inode without one or more caps, we do
1956  * this indirectly: if a cap is unused, we prune its aliases, at which
1957  * point the inode will hopefully get dropped to.
1958  *
1959  * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1960  * memory pressure from the MDS, though, so it needn't be perfect.
1961  */
1962 static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1963 {
1964         int *remaining = arg;
1965         struct ceph_inode_info *ci = ceph_inode(inode);
1966         int used, wanted, oissued, mine;
1967
1968         if (*remaining <= 0)
1969                 return -1;
1970
1971         spin_lock(&ci->i_ceph_lock);
1972         mine = cap->issued | cap->implemented;
1973         used = __ceph_caps_used(ci);
1974         wanted = __ceph_caps_file_wanted(ci);
1975         oissued = __ceph_caps_issued_other(ci, cap);
1976
1977         dout("trim_caps_cb %p cap %p mine %s oissued %s used %s wanted %s\n",
1978              inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1979              ceph_cap_string(used), ceph_cap_string(wanted));
1980         if (cap == ci->i_auth_cap) {
1981                 if (ci->i_dirty_caps || ci->i_flushing_caps ||
1982                     !list_empty(&ci->i_cap_snaps))
1983                         goto out;
1984                 if ((used | wanted) & CEPH_CAP_ANY_WR)
1985                         goto out;
1986                 /* Note: it's possible that i_filelock_ref becomes non-zero
1987                  * after dropping auth caps. It doesn't hurt because reply
1988                  * of lock mds request will re-add auth caps. */
1989                 if (atomic_read(&ci->i_filelock_ref) > 0)
1990                         goto out;
1991         }
1992         /* The inode has cached pages, but it's no longer used.
1993          * we can safely drop it */
1994         if (S_ISREG(inode->i_mode) &&
1995             wanted == 0 && used == CEPH_CAP_FILE_CACHE &&
1996             !(oissued & CEPH_CAP_FILE_CACHE)) {
1997           used = 0;
1998           oissued = 0;
1999         }
2000         if ((used | wanted) & ~oissued & mine)
2001                 goto out;   /* we need these caps */
2002
2003         if (oissued) {
2004                 /* we aren't the only cap.. just remove us */
2005                 ceph_remove_cap(cap, true);
2006                 (*remaining)--;
2007         } else {
2008                 struct dentry *dentry;
2009                 /* try dropping referring dentries */
2010                 spin_unlock(&ci->i_ceph_lock);
2011                 dentry = d_find_any_alias(inode);
2012                 if (dentry && drop_negative_children(dentry)) {
2013                         int count;
2014                         dput(dentry);
2015                         d_prune_aliases(inode);
2016                         count = atomic_read(&inode->i_count);
2017                         if (count == 1)
2018                                 (*remaining)--;
2019                         dout("trim_caps_cb %p cap %p pruned, count now %d\n",
2020                              inode, cap, count);
2021                 } else {
2022                         dput(dentry);
2023                 }
2024                 return 0;
2025         }
2026
2027 out:
2028         spin_unlock(&ci->i_ceph_lock);
2029         return 0;
2030 }
2031
2032 /*
2033  * Trim session cap count down to some max number.
2034  */
2035 int ceph_trim_caps(struct ceph_mds_client *mdsc,
2036                    struct ceph_mds_session *session,
2037                    int max_caps)
2038 {
2039         int trim_caps = session->s_nr_caps - max_caps;
2040
2041         dout("trim_caps mds%d start: %d / %d, trim %d\n",
2042              session->s_mds, session->s_nr_caps, max_caps, trim_caps);
2043         if (trim_caps > 0) {
2044                 int remaining = trim_caps;
2045
2046                 ceph_iterate_session_caps(session, trim_caps_cb, &remaining);
2047                 dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
2048                      session->s_mds, session->s_nr_caps, max_caps,
2049                         trim_caps - remaining);
2050         }
2051
2052         ceph_flush_cap_releases(mdsc, session);
2053         return 0;
2054 }
2055
2056 static int check_caps_flush(struct ceph_mds_client *mdsc,
2057                             u64 want_flush_tid)
2058 {
2059         int ret = 1;
2060
2061         spin_lock(&mdsc->cap_dirty_lock);
2062         if (!list_empty(&mdsc->cap_flush_list)) {
2063                 struct ceph_cap_flush *cf =
2064                         list_first_entry(&mdsc->cap_flush_list,
2065                                          struct ceph_cap_flush, g_list);
2066                 if (cf->tid <= want_flush_tid) {
2067                         dout("check_caps_flush still flushing tid "
2068                              "%llu <= %llu\n", cf->tid, want_flush_tid);
2069                         ret = 0;
2070                 }
2071         }
2072         spin_unlock(&mdsc->cap_dirty_lock);
2073         return ret;
2074 }
2075
2076 /*
2077  * flush all dirty inode data to disk.
2078  *
2079  * returns true if we've flushed through want_flush_tid
2080  */
2081 static void wait_caps_flush(struct ceph_mds_client *mdsc,
2082                             u64 want_flush_tid)
2083 {
2084         dout("check_caps_flush want %llu\n", want_flush_tid);
2085
2086         wait_event(mdsc->cap_flushing_wq,
2087                    check_caps_flush(mdsc, want_flush_tid));
2088
2089         dout("check_caps_flush ok, flushed thru %llu\n", want_flush_tid);
2090 }
2091
2092 /*
2093  * called under s_mutex
2094  */
2095 static void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
2096                                    struct ceph_mds_session *session)
2097 {
2098         struct ceph_msg *msg = NULL;
2099         struct ceph_mds_cap_release *head;
2100         struct ceph_mds_cap_item *item;
2101         struct ceph_osd_client *osdc = &mdsc->fsc->client->osdc;
2102         struct ceph_cap *cap;
2103         LIST_HEAD(tmp_list);
2104         int num_cap_releases;
2105         __le32  barrier, *cap_barrier;
2106
2107         down_read(&osdc->lock);
2108         barrier = cpu_to_le32(osdc->epoch_barrier);
2109         up_read(&osdc->lock);
2110
2111         spin_lock(&session->s_cap_lock);
2112 again:
2113         list_splice_init(&session->s_cap_releases, &tmp_list);
2114         num_cap_releases = session->s_num_cap_releases;
2115         session->s_num_cap_releases = 0;
2116         spin_unlock(&session->s_cap_lock);
2117
2118         while (!list_empty(&tmp_list)) {
2119                 if (!msg) {
2120                         msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE,
2121                                         PAGE_SIZE, GFP_NOFS, false);
2122                         if (!msg)
2123                                 goto out_err;
2124                         head = msg->front.iov_base;
2125                         head->num = cpu_to_le32(0);
2126                         msg->front.iov_len = sizeof(*head);
2127
2128                         msg->hdr.version = cpu_to_le16(2);
2129                         msg->hdr.compat_version = cpu_to_le16(1);
2130                 }
2131
2132                 cap = list_first_entry(&tmp_list, struct ceph_cap,
2133                                         session_caps);
2134                 list_del(&cap->session_caps);
2135                 num_cap_releases--;
2136
2137                 head = msg->front.iov_base;
2138                 put_unaligned_le32(get_unaligned_le32(&head->num) + 1,
2139                                    &head->num);
2140                 item = msg->front.iov_base + msg->front.iov_len;
2141                 item->ino = cpu_to_le64(cap->cap_ino);
2142                 item->cap_id = cpu_to_le64(cap->cap_id);
2143                 item->migrate_seq = cpu_to_le32(cap->mseq);
2144                 item->seq = cpu_to_le32(cap->issue_seq);
2145                 msg->front.iov_len += sizeof(*item);
2146
2147                 ceph_put_cap(mdsc, cap);
2148
2149                 if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
2150                         // Append cap_barrier field
2151                         cap_barrier = msg->front.iov_base + msg->front.iov_len;
2152                         *cap_barrier = barrier;
2153                         msg->front.iov_len += sizeof(*cap_barrier);
2154
2155                         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2156                         dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
2157                         ceph_con_send(&session->s_con, msg);
2158                         msg = NULL;
2159                 }
2160         }
2161
2162         BUG_ON(num_cap_releases != 0);
2163
2164         spin_lock(&session->s_cap_lock);
2165         if (!list_empty(&session->s_cap_releases))
2166                 goto again;
2167         spin_unlock(&session->s_cap_lock);
2168
2169         if (msg) {
2170                 // Append cap_barrier field
2171                 cap_barrier = msg->front.iov_base + msg->front.iov_len;
2172                 *cap_barrier = barrier;
2173                 msg->front.iov_len += sizeof(*cap_barrier);
2174
2175                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2176                 dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
2177                 ceph_con_send(&session->s_con, msg);
2178         }
2179         return;
2180 out_err:
2181         pr_err("send_cap_releases mds%d, failed to allocate message\n",
2182                 session->s_mds);
2183         spin_lock(&session->s_cap_lock);
2184         list_splice(&tmp_list, &session->s_cap_releases);
2185         session->s_num_cap_releases += num_cap_releases;
2186         spin_unlock(&session->s_cap_lock);
2187 }
2188
2189 static void ceph_cap_release_work(struct work_struct *work)
2190 {
2191         struct ceph_mds_session *session =
2192                 container_of(work, struct ceph_mds_session, s_cap_release_work);
2193
2194         mutex_lock(&session->s_mutex);
2195         if (session->s_state == CEPH_MDS_SESSION_OPEN ||
2196             session->s_state == CEPH_MDS_SESSION_HUNG)
2197                 ceph_send_cap_releases(session->s_mdsc, session);
2198         mutex_unlock(&session->s_mutex);
2199         ceph_put_mds_session(session);
2200 }
2201
2202 void ceph_flush_cap_releases(struct ceph_mds_client *mdsc,
2203                              struct ceph_mds_session *session)
2204 {
2205         if (mdsc->stopping)
2206                 return;
2207
2208         ceph_get_mds_session(session);
2209         if (queue_work(mdsc->fsc->cap_wq,
2210                        &session->s_cap_release_work)) {
2211                 dout("cap release work queued\n");
2212         } else {
2213                 ceph_put_mds_session(session);
2214                 dout("failed to queue cap release work\n");
2215         }
2216 }
2217
2218 /*
2219  * caller holds session->s_cap_lock
2220  */
2221 void __ceph_queue_cap_release(struct ceph_mds_session *session,
2222                               struct ceph_cap *cap)
2223 {
2224         list_add_tail(&cap->session_caps, &session->s_cap_releases);
2225         session->s_num_cap_releases++;
2226
2227         if (!(session->s_num_cap_releases % CEPH_CAPS_PER_RELEASE))
2228                 ceph_flush_cap_releases(session->s_mdsc, session);
2229 }
2230
2231 static void ceph_cap_reclaim_work(struct work_struct *work)
2232 {
2233         struct ceph_mds_client *mdsc =
2234                 container_of(work, struct ceph_mds_client, cap_reclaim_work);
2235         int ret = ceph_trim_dentries(mdsc);
2236         if (ret == -EAGAIN)
2237                 ceph_queue_cap_reclaim_work(mdsc);
2238 }
2239
2240 void ceph_queue_cap_reclaim_work(struct ceph_mds_client *mdsc)
2241 {
2242         if (mdsc->stopping)
2243                 return;
2244
2245         if (queue_work(mdsc->fsc->cap_wq, &mdsc->cap_reclaim_work)) {
2246                 dout("caps reclaim work queued\n");
2247         } else {
2248                 dout("failed to queue caps release work\n");
2249         }
2250 }
2251
2252 void ceph_reclaim_caps_nr(struct ceph_mds_client *mdsc, int nr)
2253 {
2254         int val;
2255         if (!nr)
2256                 return;
2257         val = atomic_add_return(nr, &mdsc->cap_reclaim_pending);
2258         if ((val % CEPH_CAPS_PER_RELEASE) < nr) {
2259                 atomic_set(&mdsc->cap_reclaim_pending, 0);
2260                 ceph_queue_cap_reclaim_work(mdsc);
2261         }
2262 }
2263
2264 /*
2265  * requests
2266  */
2267
2268 int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
2269                                     struct inode *dir)
2270 {
2271         struct ceph_inode_info *ci = ceph_inode(dir);
2272         struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info;
2273         struct ceph_mount_options *opt = req->r_mdsc->fsc->mount_options;
2274         size_t size = sizeof(struct ceph_mds_reply_dir_entry);
2275         unsigned int num_entries;
2276         int order;
2277
2278         spin_lock(&ci->i_ceph_lock);
2279         num_entries = ci->i_files + ci->i_subdirs;
2280         spin_unlock(&ci->i_ceph_lock);
2281         num_entries = max(num_entries, 1U);
2282         num_entries = min(num_entries, opt->max_readdir);
2283
2284         order = get_order(size * num_entries);
2285         while (order >= 0) {
2286                 rinfo->dir_entries = (void*)__get_free_pages(GFP_KERNEL |
2287                                                              __GFP_NOWARN,
2288                                                              order);
2289                 if (rinfo->dir_entries)
2290                         break;
2291                 order--;
2292         }
2293         if (!rinfo->dir_entries)
2294                 return -ENOMEM;
2295
2296         num_entries = (PAGE_SIZE << order) / size;
2297         num_entries = min(num_entries, opt->max_readdir);
2298
2299         rinfo->dir_buf_size = PAGE_SIZE << order;
2300         req->r_num_caps = num_entries + 1;
2301         req->r_args.readdir.max_entries = cpu_to_le32(num_entries);
2302         req->r_args.readdir.max_bytes = cpu_to_le32(opt->max_readdir_bytes);
2303         return 0;
2304 }
2305
2306 /*
2307  * Create an mds request.
2308  */
2309 struct ceph_mds_request *
2310 ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
2311 {
2312         struct ceph_mds_request *req;
2313
2314         req = kmem_cache_zalloc(ceph_mds_request_cachep, GFP_NOFS);
2315         if (!req)
2316                 return ERR_PTR(-ENOMEM);
2317
2318         mutex_init(&req->r_fill_mutex);
2319         req->r_mdsc = mdsc;
2320         req->r_started = jiffies;
2321         req->r_start_latency = ktime_get();
2322         req->r_resend_mds = -1;
2323         INIT_LIST_HEAD(&req->r_unsafe_dir_item);
2324         INIT_LIST_HEAD(&req->r_unsafe_target_item);
2325         req->r_fmode = -1;
2326         kref_init(&req->r_kref);
2327         RB_CLEAR_NODE(&req->r_node);
2328         INIT_LIST_HEAD(&req->r_wait);
2329         init_completion(&req->r_completion);
2330         init_completion(&req->r_safe_completion);
2331         INIT_LIST_HEAD(&req->r_unsafe_item);
2332
2333         ktime_get_coarse_real_ts64(&req->r_stamp);
2334
2335         req->r_op = op;
2336         req->r_direct_mode = mode;
2337         return req;
2338 }
2339
2340 /*
2341  * return oldest (lowest) request, tid in request tree, 0 if none.
2342  *
2343  * called under mdsc->mutex.
2344  */
2345 static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
2346 {
2347         if (RB_EMPTY_ROOT(&mdsc->request_tree))
2348                 return NULL;
2349         return rb_entry(rb_first(&mdsc->request_tree),
2350                         struct ceph_mds_request, r_node);
2351 }
2352
2353 static inline  u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
2354 {
2355         return mdsc->oldest_tid;
2356 }
2357
2358 /*
2359  * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
2360  * on build_path_from_dentry in fs/cifs/dir.c.
2361  *
2362  * If @stop_on_nosnap, generate path relative to the first non-snapped
2363  * inode.
2364  *
2365  * Encode hidden .snap dirs as a double /, i.e.
2366  *   foo/.snap/bar -> foo//bar
2367  */
2368 char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *pbase,
2369                            int stop_on_nosnap)
2370 {
2371         struct dentry *temp;
2372         char *path;
2373         int pos;
2374         unsigned seq;
2375         u64 base;
2376
2377         if (!dentry)
2378                 return ERR_PTR(-EINVAL);
2379
2380         path = __getname();
2381         if (!path)
2382                 return ERR_PTR(-ENOMEM);
2383 retry:
2384         pos = PATH_MAX - 1;
2385         path[pos] = '\0';
2386
2387         seq = read_seqbegin(&rename_lock);
2388         rcu_read_lock();
2389         temp = dentry;
2390         for (;;) {
2391                 struct inode *inode;
2392
2393                 spin_lock(&temp->d_lock);
2394                 inode = d_inode(temp);
2395                 if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
2396                         dout("build_path path+%d: %p SNAPDIR\n",
2397                              pos, temp);
2398                 } else if (stop_on_nosnap && inode && dentry != temp &&
2399                            ceph_snap(inode) == CEPH_NOSNAP) {
2400                         spin_unlock(&temp->d_lock);
2401                         pos++; /* get rid of any prepended '/' */
2402                         break;
2403                 } else {
2404                         pos -= temp->d_name.len;
2405                         if (pos < 0) {
2406                                 spin_unlock(&temp->d_lock);
2407                                 break;
2408                         }
2409                         memcpy(path + pos, temp->d_name.name, temp->d_name.len);
2410                 }
2411                 spin_unlock(&temp->d_lock);
2412                 temp = READ_ONCE(temp->d_parent);
2413
2414                 /* Are we at the root? */
2415                 if (IS_ROOT(temp))
2416                         break;
2417
2418                 /* Are we out of buffer? */
2419                 if (--pos < 0)
2420                         break;
2421
2422                 path[pos] = '/';
2423         }
2424         base = ceph_ino(d_inode(temp));
2425         rcu_read_unlock();
2426
2427         if (read_seqretry(&rename_lock, seq))
2428                 goto retry;
2429
2430         if (pos < 0) {
2431                 /*
2432                  * A rename didn't occur, but somehow we didn't end up where
2433                  * we thought we would. Throw a warning and try again.
2434                  */
2435                 pr_warn("build_path did not end path lookup where "
2436                         "expected, pos is %d\n", pos);
2437                 goto retry;
2438         }
2439
2440         *pbase = base;
2441         *plen = PATH_MAX - 1 - pos;
2442         dout("build_path on %p %d built %llx '%.*s'\n",
2443              dentry, d_count(dentry), base, *plen, path + pos);
2444         return path + pos;
2445 }
2446
2447 static int build_dentry_path(struct dentry *dentry, struct inode *dir,
2448                              const char **ppath, int *ppathlen, u64 *pino,
2449                              bool *pfreepath, bool parent_locked)
2450 {
2451         char *path;
2452
2453         rcu_read_lock();
2454         if (!dir)
2455                 dir = d_inode_rcu(dentry->d_parent);
2456         if (dir && parent_locked && ceph_snap(dir) == CEPH_NOSNAP) {
2457                 *pino = ceph_ino(dir);
2458                 rcu_read_unlock();
2459                 *ppath = dentry->d_name.name;
2460                 *ppathlen = dentry->d_name.len;
2461                 return 0;
2462         }
2463         rcu_read_unlock();
2464         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2465         if (IS_ERR(path))
2466                 return PTR_ERR(path);
2467         *ppath = path;
2468         *pfreepath = true;
2469         return 0;
2470 }
2471
2472 static int build_inode_path(struct inode *inode,
2473                             const char **ppath, int *ppathlen, u64 *pino,
2474                             bool *pfreepath)
2475 {
2476         struct dentry *dentry;
2477         char *path;
2478
2479         if (ceph_snap(inode) == CEPH_NOSNAP) {
2480                 *pino = ceph_ino(inode);
2481                 *ppathlen = 0;
2482                 return 0;
2483         }
2484         dentry = d_find_alias(inode);
2485         path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
2486         dput(dentry);
2487         if (IS_ERR(path))
2488                 return PTR_ERR(path);
2489         *ppath = path;
2490         *pfreepath = true;
2491         return 0;
2492 }
2493
2494 /*
2495  * request arguments may be specified via an inode *, a dentry *, or
2496  * an explicit ino+path.
2497  */
2498 static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
2499                                   struct inode *rdiri, const char *rpath,
2500                                   u64 rino, const char **ppath, int *pathlen,
2501                                   u64 *ino, bool *freepath, bool parent_locked)
2502 {
2503         int r = 0;
2504
2505         if (rinode) {
2506                 r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
2507                 dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
2508                      ceph_snap(rinode));
2509         } else if (rdentry) {
2510                 r = build_dentry_path(rdentry, rdiri, ppath, pathlen, ino,
2511                                         freepath, parent_locked);
2512                 dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
2513                      *ppath);
2514         } else if (rpath || rino) {
2515                 *ino = rino;
2516                 *ppath = rpath;
2517                 *pathlen = rpath ? strlen(rpath) : 0;
2518                 dout(" path %.*s\n", *pathlen, rpath);
2519         }
2520
2521         return r;
2522 }
2523
2524 static void encode_timestamp_and_gids(void **p,
2525                                       const struct ceph_mds_request *req)
2526 {
2527         struct ceph_timespec ts;
2528         int i;
2529
2530         ceph_encode_timespec64(&ts, &req->r_stamp);
2531         ceph_encode_copy(p, &ts, sizeof(ts));
2532
2533         /* gid_list */
2534         ceph_encode_32(p, req->r_cred->group_info->ngroups);
2535         for (i = 0; i < req->r_cred->group_info->ngroups; i++)
2536                 ceph_encode_64(p, from_kgid(&init_user_ns,
2537                                             req->r_cred->group_info->gid[i]));
2538 }
2539
2540 /*
2541  * called under mdsc->mutex
2542  */
2543 static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
2544                                                struct ceph_mds_request *req,
2545                                                bool drop_cap_releases)
2546 {
2547         int mds = session->s_mds;
2548         struct ceph_mds_client *mdsc = session->s_mdsc;
2549         struct ceph_msg *msg;
2550         struct ceph_mds_request_head_old *head;
2551         const char *path1 = NULL;
2552         const char *path2 = NULL;
2553         u64 ino1 = 0, ino2 = 0;
2554         int pathlen1 = 0, pathlen2 = 0;
2555         bool freepath1 = false, freepath2 = false;
2556         int len;
2557         u16 releases;
2558         void *p, *end;
2559         int ret;
2560         bool legacy = !(session->s_con.peer_features & CEPH_FEATURE_FS_BTIME);
2561
2562         ret = set_request_path_attr(req->r_inode, req->r_dentry,
2563                               req->r_parent, req->r_path1, req->r_ino1.ino,
2564                               &path1, &pathlen1, &ino1, &freepath1,
2565                               test_bit(CEPH_MDS_R_PARENT_LOCKED,
2566                                         &req->r_req_flags));
2567         if (ret < 0) {
2568                 msg = ERR_PTR(ret);
2569                 goto out;
2570         }
2571
2572         /* If r_old_dentry is set, then assume that its parent is locked */
2573         ret = set_request_path_attr(NULL, req->r_old_dentry,
2574                               req->r_old_dentry_dir,
2575                               req->r_path2, req->r_ino2.ino,
2576                               &path2, &pathlen2, &ino2, &freepath2, true);
2577         if (ret < 0) {
2578                 msg = ERR_PTR(ret);
2579                 goto out_free1;
2580         }
2581
2582         len = legacy ? sizeof(*head) : sizeof(struct ceph_mds_request_head);
2583         len += pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
2584                 sizeof(struct ceph_timespec);
2585         len += sizeof(u32) + (sizeof(u64) * req->r_cred->group_info->ngroups);
2586
2587         /* calculate (max) length for cap releases */
2588         len += sizeof(struct ceph_mds_request_release) *
2589                 (!!req->r_inode_drop + !!req->r_dentry_drop +
2590                  !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
2591
2592         if (req->r_dentry_drop)
2593                 len += pathlen1;
2594         if (req->r_old_dentry_drop)
2595                 len += pathlen2;
2596
2597         msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
2598         if (!msg) {
2599                 msg = ERR_PTR(-ENOMEM);
2600                 goto out_free2;
2601         }
2602
2603         msg->hdr.tid = cpu_to_le64(req->r_tid);
2604
2605         /*
2606          * The old ceph_mds_request_head didn't contain a version field, and
2607          * one was added when we moved the message version from 3->4.
2608          */
2609         if (legacy) {
2610                 msg->hdr.version = cpu_to_le16(3);
2611                 head = msg->front.iov_base;
2612                 p = msg->front.iov_base + sizeof(*head);
2613         } else {
2614                 struct ceph_mds_request_head *new_head = msg->front.iov_base;
2615
2616                 msg->hdr.version = cpu_to_le16(4);
2617                 new_head->version = cpu_to_le16(CEPH_MDS_REQUEST_HEAD_VERSION);
2618                 head = (struct ceph_mds_request_head_old *)&new_head->oldest_client_tid;
2619                 p = msg->front.iov_base + sizeof(*new_head);
2620         }
2621
2622         end = msg->front.iov_base + msg->front.iov_len;
2623
2624         head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
2625         head->op = cpu_to_le32(req->r_op);
2626         head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns,
2627                                                  req->r_cred->fsuid));
2628         head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns,
2629                                                  req->r_cred->fsgid));
2630         head->ino = cpu_to_le64(req->r_deleg_ino);
2631         head->args = req->r_args;
2632
2633         ceph_encode_filepath(&p, end, ino1, path1);
2634         ceph_encode_filepath(&p, end, ino2, path2);
2635
2636         /* make note of release offset, in case we need to replay */
2637         req->r_request_release_offset = p - msg->front.iov_base;
2638
2639         /* cap releases */
2640         releases = 0;
2641         if (req->r_inode_drop)
2642                 releases += ceph_encode_inode_release(&p,
2643                       req->r_inode ? req->r_inode : d_inode(req->r_dentry),
2644                       mds, req->r_inode_drop, req->r_inode_unless,
2645                       req->r_op == CEPH_MDS_OP_READDIR);
2646         if (req->r_dentry_drop)
2647                 releases += ceph_encode_dentry_release(&p, req->r_dentry,
2648                                 req->r_parent, mds, req->r_dentry_drop,
2649                                 req->r_dentry_unless);
2650         if (req->r_old_dentry_drop)
2651                 releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
2652                                 req->r_old_dentry_dir, mds,
2653                                 req->r_old_dentry_drop,
2654                                 req->r_old_dentry_unless);
2655         if (req->r_old_inode_drop)
2656                 releases += ceph_encode_inode_release(&p,
2657                       d_inode(req->r_old_dentry),
2658                       mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
2659
2660         if (drop_cap_releases) {
2661                 releases = 0;
2662                 p = msg->front.iov_base + req->r_request_release_offset;
2663         }
2664
2665         head->num_releases = cpu_to_le16(releases);
2666
2667         encode_timestamp_and_gids(&p, req);
2668
2669         if (WARN_ON_ONCE(p > end)) {
2670                 ceph_msg_put(msg);
2671                 msg = ERR_PTR(-ERANGE);
2672                 goto out_free2;
2673         }
2674
2675         msg->front.iov_len = p - msg->front.iov_base;
2676         msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2677
2678         if (req->r_pagelist) {
2679                 struct ceph_pagelist *pagelist = req->r_pagelist;
2680                 ceph_msg_data_add_pagelist(msg, pagelist);
2681                 msg->hdr.data_len = cpu_to_le32(pagelist->length);
2682         } else {
2683                 msg->hdr.data_len = 0;
2684         }
2685
2686         msg->hdr.data_off = cpu_to_le16(0);
2687
2688 out_free2:
2689         if (freepath2)
2690                 ceph_mdsc_free_path((char *)path2, pathlen2);
2691 out_free1:
2692         if (freepath1)
2693                 ceph_mdsc_free_path((char *)path1, pathlen1);
2694 out:
2695         return msg;
2696 }
2697
2698 /*
2699  * called under mdsc->mutex if error, under no mutex if
2700  * success.
2701  */
2702 static void complete_request(struct ceph_mds_client *mdsc,
2703                              struct ceph_mds_request *req)
2704 {
2705         req->r_end_latency = ktime_get();
2706
2707         if (req->r_callback)
2708                 req->r_callback(mdsc, req);
2709         complete_all(&req->r_completion);
2710 }
2711
2712 static struct ceph_mds_request_head_old *
2713 find_old_request_head(void *p, u64 features)
2714 {
2715         bool legacy = !(features & CEPH_FEATURE_FS_BTIME);
2716         struct ceph_mds_request_head *new_head;
2717
2718         if (legacy)
2719                 return (struct ceph_mds_request_head_old *)p;
2720         new_head = (struct ceph_mds_request_head *)p;
2721         return (struct ceph_mds_request_head_old *)&new_head->oldest_client_tid;
2722 }
2723
2724 /*
2725  * called under mdsc->mutex
2726  */
2727 static int __prepare_send_request(struct ceph_mds_session *session,
2728                                   struct ceph_mds_request *req,
2729                                   bool drop_cap_releases)
2730 {
2731         int mds = session->s_mds;
2732         struct ceph_mds_client *mdsc = session->s_mdsc;
2733         struct ceph_mds_request_head_old *rhead;
2734         struct ceph_msg *msg;
2735         int flags = 0;
2736
2737         req->r_attempts++;
2738         if (req->r_inode) {
2739                 struct ceph_cap *cap =
2740                         ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
2741
2742                 if (cap)
2743                         req->r_sent_on_mseq = cap->mseq;
2744                 else
2745                         req->r_sent_on_mseq = -1;
2746         }
2747         dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
2748              req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
2749
2750         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
2751                 void *p;
2752
2753                 /*
2754                  * Replay.  Do not regenerate message (and rebuild
2755                  * paths, etc.); just use the original message.
2756                  * Rebuilding paths will break for renames because
2757                  * d_move mangles the src name.
2758                  */
2759                 msg = req->r_request;
2760                 rhead = find_old_request_head(msg->front.iov_base,
2761                                               session->s_con.peer_features);
2762
2763                 flags = le32_to_cpu(rhead->flags);
2764                 flags |= CEPH_MDS_FLAG_REPLAY;
2765                 rhead->flags = cpu_to_le32(flags);
2766
2767                 if (req->r_target_inode)
2768                         rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
2769
2770                 rhead->num_retry = req->r_attempts - 1;
2771
2772                 /* remove cap/dentry releases from message */
2773                 rhead->num_releases = 0;
2774
2775                 p = msg->front.iov_base + req->r_request_release_offset;
2776                 encode_timestamp_and_gids(&p, req);
2777
2778                 msg->front.iov_len = p - msg->front.iov_base;
2779                 msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
2780                 return 0;
2781         }
2782
2783         if (req->r_request) {
2784                 ceph_msg_put(req->r_request);
2785                 req->r_request = NULL;
2786         }
2787         msg = create_request_message(session, req, drop_cap_releases);
2788         if (IS_ERR(msg)) {
2789                 req->r_err = PTR_ERR(msg);
2790                 return PTR_ERR(msg);
2791         }
2792         req->r_request = msg;
2793
2794         rhead = find_old_request_head(msg->front.iov_base,
2795                                       session->s_con.peer_features);
2796         rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
2797         if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2798                 flags |= CEPH_MDS_FLAG_REPLAY;
2799         if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags))
2800                 flags |= CEPH_MDS_FLAG_ASYNC;
2801         if (req->r_parent)
2802                 flags |= CEPH_MDS_FLAG_WANT_DENTRY;
2803         rhead->flags = cpu_to_le32(flags);
2804         rhead->num_fwd = req->r_num_fwd;
2805         rhead->num_retry = req->r_attempts - 1;
2806
2807         dout(" r_parent = %p\n", req->r_parent);
2808         return 0;
2809 }
2810
2811 /*
2812  * called under mdsc->mutex
2813  */
2814 static int __send_request(struct ceph_mds_session *session,
2815                           struct ceph_mds_request *req,
2816                           bool drop_cap_releases)
2817 {
2818         int err;
2819
2820         err = __prepare_send_request(session, req, drop_cap_releases);
2821         if (!err) {
2822                 ceph_msg_get(req->r_request);
2823                 ceph_con_send(&session->s_con, req->r_request);
2824         }
2825
2826         return err;
2827 }
2828
2829 /*
2830  * send request, or put it on the appropriate wait list.
2831  */
2832 static void __do_request(struct ceph_mds_client *mdsc,
2833                         struct ceph_mds_request *req)
2834 {
2835         struct ceph_mds_session *session = NULL;
2836         int mds = -1;
2837         int err = 0;
2838         bool random;
2839
2840         if (req->r_err || test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
2841                 if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags))
2842                         __unregister_request(mdsc, req);
2843                 return;
2844         }
2845
2846         if (req->r_timeout &&
2847             time_after_eq(jiffies, req->r_started + req->r_timeout)) {
2848                 dout("do_request timed out\n");
2849                 err = -ETIMEDOUT;
2850                 goto finish;
2851         }
2852         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
2853                 dout("do_request forced umount\n");
2854                 err = -EIO;
2855                 goto finish;
2856         }
2857         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_MOUNTING) {
2858                 if (mdsc->mdsmap_err) {
2859                         err = mdsc->mdsmap_err;
2860                         dout("do_request mdsmap err %d\n", err);
2861                         goto finish;
2862                 }
2863                 if (mdsc->mdsmap->m_epoch == 0) {
2864                         dout("do_request no mdsmap, waiting for map\n");
2865                         list_add(&req->r_wait, &mdsc->waiting_for_map);
2866                         return;
2867                 }
2868                 if (!(mdsc->fsc->mount_options->flags &
2869                       CEPH_MOUNT_OPT_MOUNTWAIT) &&
2870                     !ceph_mdsmap_is_cluster_available(mdsc->mdsmap)) {
2871                         err = -EHOSTUNREACH;
2872                         goto finish;
2873                 }
2874         }
2875
2876         put_request_session(req);
2877
2878         mds = __choose_mds(mdsc, req, &random);
2879         if (mds < 0 ||
2880             ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
2881                 if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags)) {
2882                         err = -EJUKEBOX;
2883                         goto finish;
2884                 }
2885                 dout("do_request no mds or not active, waiting for map\n");
2886                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2887                 return;
2888         }
2889
2890         /* get, open session */
2891         session = __ceph_lookup_mds_session(mdsc, mds);
2892         if (!session) {
2893                 session = register_session(mdsc, mds);
2894                 if (IS_ERR(session)) {
2895                         err = PTR_ERR(session);
2896                         goto finish;
2897                 }
2898         }
2899         req->r_session = ceph_get_mds_session(session);
2900
2901         dout("do_request mds%d session %p state %s\n", mds, session,
2902              ceph_session_state_name(session->s_state));
2903         if (session->s_state != CEPH_MDS_SESSION_OPEN &&
2904             session->s_state != CEPH_MDS_SESSION_HUNG) {
2905                 /*
2906                  * We cannot queue async requests since the caps and delegated
2907                  * inodes are bound to the session. Just return -EJUKEBOX and
2908                  * let the caller retry a sync request in that case.
2909                  */
2910                 if (test_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags)) {
2911                         err = -EJUKEBOX;
2912                         goto out_session;
2913                 }
2914
2915                 /*
2916                  * If the session has been REJECTED, then return a hard error,
2917                  * unless it's a CLEANRECOVER mount, in which case we'll queue
2918                  * it to the mdsc queue.
2919                  */
2920                 if (session->s_state == CEPH_MDS_SESSION_REJECTED) {
2921                         if (ceph_test_mount_opt(mdsc->fsc, CLEANRECOVER))
2922                                 list_add(&req->r_wait, &mdsc->waiting_for_map);
2923                         else
2924                                 err = -EACCES;
2925                         goto out_session;
2926                 }
2927
2928                 if (session->s_state == CEPH_MDS_SESSION_NEW ||
2929                     session->s_state == CEPH_MDS_SESSION_CLOSING) {
2930                         err = __open_session(mdsc, session);
2931                         if (err)
2932                                 goto out_session;
2933                         /* retry the same mds later */
2934                         if (random)
2935                                 req->r_resend_mds = mds;
2936                 }
2937                 list_add(&req->r_wait, &session->s_waiting);
2938                 goto out_session;
2939         }
2940
2941         /* send request */
2942         req->r_resend_mds = -1;   /* forget any previous mds hint */
2943
2944         if (req->r_request_started == 0)   /* note request start time */
2945                 req->r_request_started = jiffies;
2946
2947         err = __send_request(session, req, false);
2948
2949 out_session:
2950         ceph_put_mds_session(session);
2951 finish:
2952         if (err) {
2953                 dout("__do_request early error %d\n", err);
2954                 req->r_err = err;
2955                 complete_request(mdsc, req);
2956                 __unregister_request(mdsc, req);
2957         }
2958         return;
2959 }
2960
2961 /*
2962  * called under mdsc->mutex
2963  */
2964 static void __wake_requests(struct ceph_mds_client *mdsc,
2965                             struct list_head *head)
2966 {
2967         struct ceph_mds_request *req;
2968         LIST_HEAD(tmp_list);
2969
2970         list_splice_init(head, &tmp_list);
2971
2972         while (!list_empty(&tmp_list)) {
2973                 req = list_entry(tmp_list.next,
2974                                  struct ceph_mds_request, r_wait);
2975                 list_del_init(&req->r_wait);
2976                 dout(" wake request %p tid %llu\n", req, req->r_tid);
2977                 __do_request(mdsc, req);
2978         }
2979 }
2980
2981 /*
2982  * Wake up threads with requests pending for @mds, so that they can
2983  * resubmit their requests to a possibly different mds.
2984  */
2985 static void kick_requests(struct ceph_mds_client *mdsc, int mds)
2986 {
2987         struct ceph_mds_request *req;
2988         struct rb_node *p = rb_first(&mdsc->request_tree);
2989
2990         dout("kick_requests mds%d\n", mds);
2991         while (p) {
2992                 req = rb_entry(p, struct ceph_mds_request, r_node);
2993                 p = rb_next(p);
2994                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
2995                         continue;
2996                 if (req->r_attempts > 0)
2997                         continue; /* only new requests */
2998                 if (req->r_session &&
2999                     req->r_session->s_mds == mds) {
3000                         dout(" kicking tid %llu\n", req->r_tid);
3001                         list_del_init(&req->r_wait);
3002                         __do_request(mdsc, req);
3003                 }
3004         }
3005 }
3006
3007 int ceph_mdsc_submit_request(struct ceph_mds_client *mdsc, struct inode *dir,
3008                               struct ceph_mds_request *req)
3009 {
3010         int err = 0;
3011
3012         /* take CAP_PIN refs for r_inode, r_parent, r_old_dentry */
3013         if (req->r_inode)
3014                 ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
3015         if (req->r_parent) {
3016                 struct ceph_inode_info *ci = ceph_inode(req->r_parent);
3017                 int fmode = (req->r_op & CEPH_MDS_OP_WRITE) ?
3018                             CEPH_FILE_MODE_WR : CEPH_FILE_MODE_RD;
3019                 spin_lock(&ci->i_ceph_lock);
3020                 ceph_take_cap_refs(ci, CEPH_CAP_PIN, false);
3021                 __ceph_touch_fmode(ci, mdsc, fmode);
3022                 spin_unlock(&ci->i_ceph_lock);
3023         }
3024         if (req->r_old_dentry_dir)
3025                 ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
3026                                   CEPH_CAP_PIN);
3027
3028         if (req->r_inode) {
3029                 err = ceph_wait_on_async_create(req->r_inode);
3030                 if (err) {
3031                         dout("%s: wait for async create returned: %d\n",
3032                              __func__, err);
3033                         return err;
3034                 }
3035         }
3036
3037         if (!err && req->r_old_inode) {
3038                 err = ceph_wait_on_async_create(req->r_old_inode);
3039                 if (err) {
3040                         dout("%s: wait for async create returned: %d\n",
3041                              __func__, err);
3042                         return err;
3043                 }
3044         }
3045
3046         dout("submit_request on %p for inode %p\n", req, dir);
3047         mutex_lock(&mdsc->mutex);
3048         __register_request(mdsc, req, dir);
3049         __do_request(mdsc, req);
3050         err = req->r_err;
3051         mutex_unlock(&mdsc->mutex);
3052         return err;
3053 }
3054
3055 static int ceph_mdsc_wait_request(struct ceph_mds_client *mdsc,
3056                                   struct ceph_mds_request *req)
3057 {
3058         int err;
3059
3060         /* wait */
3061         dout("do_request waiting\n");
3062         if (!req->r_timeout && req->r_wait_for_completion) {
3063                 err = req->r_wait_for_completion(mdsc, req);
3064         } else {
3065                 long timeleft = wait_for_completion_killable_timeout(
3066                                         &req->r_completion,
3067                                         ceph_timeout_jiffies(req->r_timeout));
3068                 if (timeleft > 0)
3069                         err = 0;
3070                 else if (!timeleft)
3071                         err = -ETIMEDOUT;  /* timed out */
3072                 else
3073                         err = timeleft;  /* killed */
3074         }
3075         dout("do_request waited, got %d\n", err);
3076         mutex_lock(&mdsc->mutex);
3077
3078         /* only abort if we didn't race with a real reply */
3079         if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) {
3080                 err = le32_to_cpu(req->r_reply_info.head->result);
3081         } else if (err < 0) {
3082                 dout("aborted request %lld with %d\n", req->r_tid, err);
3083
3084                 /*
3085                  * ensure we aren't running concurrently with
3086                  * ceph_fill_trace or ceph_readdir_prepopulate, which
3087                  * rely on locks (dir mutex) held by our caller.
3088                  */
3089                 mutex_lock(&req->r_fill_mutex);
3090                 req->r_err = err;
3091                 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags);
3092                 mutex_unlock(&req->r_fill_mutex);
3093
3094                 if (req->r_parent &&
3095                     (req->r_op & CEPH_MDS_OP_WRITE))
3096                         ceph_invalidate_dir_request(req);
3097         } else {
3098                 err = req->r_err;
3099         }
3100
3101         mutex_unlock(&mdsc->mutex);
3102         return err;
3103 }
3104
3105 /*
3106  * Synchrously perform an mds request.  Take care of all of the
3107  * session setup, forwarding, retry details.
3108  */
3109 int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
3110                          struct inode *dir,
3111                          struct ceph_mds_request *req)
3112 {
3113         int err;
3114
3115         dout("do_request on %p\n", req);
3116
3117         /* issue */
3118         err = ceph_mdsc_submit_request(mdsc, dir, req);
3119         if (!err)
3120                 err = ceph_mdsc_wait_request(mdsc, req);
3121         dout("do_request %p done, result %d\n", req, err);
3122         return err;
3123 }
3124
3125 /*
3126  * Invalidate dir's completeness, dentry lease state on an aborted MDS
3127  * namespace request.
3128  */
3129 void ceph_invalidate_dir_request(struct ceph_mds_request *req)
3130 {
3131         struct inode *dir = req->r_parent;
3132         struct inode *old_dir = req->r_old_dentry_dir;
3133
3134         dout("invalidate_dir_request %p %p (complete, lease(s))\n", dir, old_dir);
3135
3136         ceph_dir_clear_complete(dir);
3137         if (old_dir)
3138                 ceph_dir_clear_complete(old_dir);
3139         if (req->r_dentry)
3140                 ceph_invalidate_dentry_lease(req->r_dentry);
3141         if (req->r_old_dentry)
3142                 ceph_invalidate_dentry_lease(req->r_old_dentry);
3143 }
3144
3145 /*
3146  * Handle mds reply.
3147  *
3148  * We take the session mutex and parse and process the reply immediately.
3149  * This preserves the logical ordering of replies, capabilities, etc., sent
3150  * by the MDS as they are applied to our local cache.
3151  */
3152 static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
3153 {
3154         struct ceph_mds_client *mdsc = session->s_mdsc;
3155         struct ceph_mds_request *req;
3156         struct ceph_mds_reply_head *head = msg->front.iov_base;
3157         struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
3158         struct ceph_snap_realm *realm;
3159         u64 tid;
3160         int err, result;
3161         int mds = session->s_mds;
3162
3163         if (msg->front.iov_len < sizeof(*head)) {
3164                 pr_err("mdsc_handle_reply got corrupt (short) reply\n");
3165                 ceph_msg_dump(msg);
3166                 return;
3167         }
3168
3169         /* get request, session */
3170         tid = le64_to_cpu(msg->hdr.tid);
3171         mutex_lock(&mdsc->mutex);
3172         req = lookup_get_request(mdsc, tid);
3173         if (!req) {
3174                 dout("handle_reply on unknown tid %llu\n", tid);
3175                 mutex_unlock(&mdsc->mutex);
3176                 return;
3177         }
3178         dout("handle_reply %p\n", req);
3179
3180         /* correct session? */
3181         if (req->r_session != session) {
3182                 pr_err("mdsc_handle_reply got %llu on session mds%d"
3183                        " not mds%d\n", tid, session->s_mds,
3184                        req->r_session ? req->r_session->s_mds : -1);
3185                 mutex_unlock(&mdsc->mutex);
3186                 goto out;
3187         }
3188
3189         /* dup? */
3190         if ((test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags) && !head->safe) ||
3191             (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags) && head->safe)) {
3192                 pr_warn("got a dup %s reply on %llu from mds%d\n",
3193                            head->safe ? "safe" : "unsafe", tid, mds);
3194                 mutex_unlock(&mdsc->mutex);
3195                 goto out;
3196         }
3197         if (test_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags)) {
3198                 pr_warn("got unsafe after safe on %llu from mds%d\n",
3199                            tid, mds);
3200                 mutex_unlock(&mdsc->mutex);
3201                 goto out;
3202         }
3203
3204         result = le32_to_cpu(head->result);
3205
3206         /*
3207          * Handle an ESTALE
3208          * if we're not talking to the authority, send to them
3209          * if the authority has changed while we weren't looking,
3210          * send to new authority
3211          * Otherwise we just have to return an ESTALE
3212          */
3213         if (result == -ESTALE) {
3214                 dout("got ESTALE on request %llu\n", req->r_tid);
3215                 req->r_resend_mds = -1;
3216                 if (req->r_direct_mode != USE_AUTH_MDS) {
3217                         dout("not using auth, setting for that now\n");
3218                         req->r_direct_mode = USE_AUTH_MDS;
3219                         __do_request(mdsc, req);
3220                         mutex_unlock(&mdsc->mutex);
3221                         goto out;
3222                 } else  {
3223                         int mds = __choose_mds(mdsc, req, NULL);
3224                         if (mds >= 0 && mds != req->r_session->s_mds) {
3225                                 dout("but auth changed, so resending\n");
3226                                 __do_request(mdsc, req);
3227                                 mutex_unlock(&mdsc->mutex);
3228                                 goto out;
3229                         }
3230                 }
3231                 dout("have to return ESTALE on request %llu\n", req->r_tid);
3232         }
3233
3234
3235         if (head->safe) {
3236                 set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
3237                 __unregister_request(mdsc, req);
3238
3239                 /* last request during umount? */
3240                 if (mdsc->stopping && !__get_oldest_req(mdsc))
3241                         complete_all(&mdsc->safe_umount_waiters);
3242
3243                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
3244                         /*
3245                          * We already handled the unsafe response, now do the
3246                          * cleanup.  No need to examine the response; the MDS
3247                          * doesn't include any result info in the safe
3248                          * response.  And even if it did, there is nothing
3249                          * useful we could do with a revised return value.
3250                          */
3251                         dout("got safe reply %llu, mds%d\n", tid, mds);
3252
3253                         mutex_unlock(&mdsc->mutex);
3254                         goto out;
3255                 }
3256         } else {
3257                 set_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags);
3258                 list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
3259         }
3260
3261         dout("handle_reply tid %lld result %d\n", tid, result);
3262         rinfo = &req->r_reply_info;
3263         if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
3264                 err = parse_reply_info(session, msg, rinfo, (u64)-1);
3265         else
3266                 err = parse_reply_info(session, msg, rinfo, session->s_con.peer_features);
3267         mutex_unlock(&mdsc->mutex);
3268
3269         /* Must find target inode outside of mutexes to avoid deadlocks */
3270         if ((err >= 0) && rinfo->head->is_target) {
3271                 struct inode *in;
3272                 struct ceph_vino tvino = {
3273                         .ino  = le64_to_cpu(rinfo->targeti.in->ino),
3274                         .snap = le64_to_cpu(rinfo->targeti.in->snapid)
3275                 };
3276
3277                 in = ceph_get_inode(mdsc->fsc->sb, tvino);
3278                 if (IS_ERR(in)) {
3279                         err = PTR_ERR(in);
3280                         mutex_lock(&session->s_mutex);
3281                         goto out_err;
3282                 }
3283                 req->r_target_inode = in;
3284         }
3285
3286         mutex_lock(&session->s_mutex);
3287         if (err < 0) {
3288                 pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
3289                 ceph_msg_dump(msg);
3290                 goto out_err;
3291         }
3292
3293         /* snap trace */
3294         realm = NULL;
3295         if (rinfo->snapblob_len) {
3296                 down_write(&mdsc->snap_rwsem);
3297                 ceph_update_snap_trace(mdsc, rinfo->snapblob,
3298                                 rinfo->snapblob + rinfo->snapblob_len,
3299                                 le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP,
3300                                 &realm);
3301                 downgrade_write(&mdsc->snap_rwsem);
3302         } else {
3303                 down_read(&mdsc->snap_rwsem);
3304         }
3305
3306         /* insert trace into our cache */
3307         mutex_lock(&req->r_fill_mutex);
3308         current->journal_info = req;
3309         err = ceph_fill_trace(mdsc->fsc->sb, req);
3310         if (err == 0) {
3311                 if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
3312                                     req->r_op == CEPH_MDS_OP_LSSNAP))
3313                         ceph_readdir_prepopulate(req, req->r_session);
3314         }
3315         current->journal_info = NULL;
3316         mutex_unlock(&req->r_fill_mutex);
3317
3318         up_read(&mdsc->snap_rwsem);
3319         if (realm)
3320                 ceph_put_snap_realm(mdsc, realm);
3321
3322         if (err == 0) {
3323                 if (req->r_target_inode &&
3324                     test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
3325                         struct ceph_inode_info *ci =
3326                                 ceph_inode(req->r_target_inode);
3327                         spin_lock(&ci->i_unsafe_lock);
3328                         list_add_tail(&req->r_unsafe_target_item,
3329                                       &ci->i_unsafe_iops);
3330                         spin_unlock(&ci->i_unsafe_lock);
3331                 }
3332
3333                 ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
3334         }
3335 out_err:
3336         mutex_lock(&mdsc->mutex);
3337         if (!test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3338                 if (err) {
3339                         req->r_err = err;
3340                 } else {
3341                         req->r_reply =  ceph_msg_get(msg);
3342                         set_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags);
3343                 }
3344         } else {
3345                 dout("reply arrived after request %lld was aborted\n", tid);
3346         }
3347         mutex_unlock(&mdsc->mutex);
3348
3349         mutex_unlock(&session->s_mutex);
3350
3351         /* kick calling process */
3352         complete_request(mdsc, req);
3353
3354         ceph_update_metadata_metrics(&mdsc->metric, req->r_start_latency,
3355                                      req->r_end_latency, err);
3356 out:
3357         ceph_mdsc_put_request(req);
3358         return;
3359 }
3360
3361
3362
3363 /*
3364  * handle mds notification that our request has been forwarded.
3365  */
3366 static void handle_forward(struct ceph_mds_client *mdsc,
3367                            struct ceph_mds_session *session,
3368                            struct ceph_msg *msg)
3369 {
3370         struct ceph_mds_request *req;
3371         u64 tid = le64_to_cpu(msg->hdr.tid);
3372         u32 next_mds;
3373         u32 fwd_seq;
3374         int err = -EINVAL;
3375         void *p = msg->front.iov_base;
3376         void *end = p + msg->front.iov_len;
3377
3378         ceph_decode_need(&p, end, 2*sizeof(u32), bad);
3379         next_mds = ceph_decode_32(&p);
3380         fwd_seq = ceph_decode_32(&p);
3381
3382         mutex_lock(&mdsc->mutex);
3383         req = lookup_get_request(mdsc, tid);
3384         if (!req) {
3385                 dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
3386                 goto out;  /* dup reply? */
3387         }
3388
3389         if (test_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags)) {
3390                 dout("forward tid %llu aborted, unregistering\n", tid);
3391                 __unregister_request(mdsc, req);
3392         } else if (fwd_seq <= req->r_num_fwd) {
3393                 dout("forward tid %llu to mds%d - old seq %d <= %d\n",
3394                      tid, next_mds, req->r_num_fwd, fwd_seq);
3395         } else {
3396                 /* resend. forward race not possible; mds would drop */
3397                 dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
3398                 BUG_ON(req->r_err);
3399                 BUG_ON(test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags));
3400                 req->r_attempts = 0;
3401                 req->r_num_fwd = fwd_seq;
3402                 req->r_resend_mds = next_mds;
3403                 put_request_session(req);
3404                 __do_request(mdsc, req);
3405         }
3406         ceph_mdsc_put_request(req);
3407 out:
3408         mutex_unlock(&mdsc->mutex);
3409         return;
3410
3411 bad:
3412         pr_err("mdsc_handle_forward decode error err=%d\n", err);
3413 }
3414
3415 static int __decode_session_metadata(void **p, void *end,
3416                                      bool *blocklisted)
3417 {
3418         /* map<string,string> */
3419         u32 n;
3420         bool err_str;
3421         ceph_decode_32_safe(p, end, n, bad);
3422         while (n-- > 0) {
3423                 u32 len;
3424                 ceph_decode_32_safe(p, end, len, bad);
3425                 ceph_decode_need(p, end, len, bad);
3426                 err_str = !strncmp(*p, "error_string", len);
3427                 *p += len;
3428                 ceph_decode_32_safe(p, end, len, bad);
3429                 ceph_decode_need(p, end, len, bad);
3430                 /*
3431                  * Match "blocklisted (blacklisted)" from newer MDSes,
3432                  * or "blacklisted" from older MDSes.
3433                  */
3434                 if (err_str && strnstr(*p, "blacklisted", len))
3435                         *blocklisted = true;
3436                 *p += len;
3437         }
3438         return 0;
3439 bad:
3440         return -1;
3441 }
3442
3443 /*
3444  * handle a mds session control message
3445  */
3446 static void handle_session(struct ceph_mds_session *session,
3447                            struct ceph_msg *msg)
3448 {
3449         struct ceph_mds_client *mdsc = session->s_mdsc;
3450         int mds = session->s_mds;
3451         int msg_version = le16_to_cpu(msg->hdr.version);
3452         void *p = msg->front.iov_base;
3453         void *end = p + msg->front.iov_len;
3454         struct ceph_mds_session_head *h;
3455         u32 op;
3456         u64 seq, features = 0;
3457         int wake = 0;
3458         bool blocklisted = false;
3459
3460         /* decode */
3461         ceph_decode_need(&p, end, sizeof(*h), bad);
3462         h = p;
3463         p += sizeof(*h);
3464
3465         op = le32_to_cpu(h->op);
3466         seq = le64_to_cpu(h->seq);
3467
3468         if (msg_version >= 3) {
3469                 u32 len;
3470                 /* version >= 2, metadata */
3471                 if (__decode_session_metadata(&p, end, &blocklisted) < 0)
3472                         goto bad;
3473                 /* version >= 3, feature bits */
3474                 ceph_decode_32_safe(&p, end, len, bad);
3475                 if (len) {
3476                         ceph_decode_64_safe(&p, end, features, bad);
3477                         p += len - sizeof(features);
3478                 }
3479         }
3480
3481         mutex_lock(&mdsc->mutex);
3482         if (op == CEPH_SESSION_CLOSE) {
3483                 ceph_get_mds_session(session);
3484                 __unregister_session(mdsc, session);
3485         }
3486         /* FIXME: this ttl calculation is generous */
3487         session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
3488         mutex_unlock(&mdsc->mutex);
3489
3490         mutex_lock(&session->s_mutex);
3491
3492         dout("handle_session mds%d %s %p state %s seq %llu\n",
3493              mds, ceph_session_op_name(op), session,
3494              ceph_session_state_name(session->s_state), seq);
3495
3496         if (session->s_state == CEPH_MDS_SESSION_HUNG) {
3497                 session->s_state = CEPH_MDS_SESSION_OPEN;
3498                 pr_info("mds%d came back\n", session->s_mds);
3499         }
3500
3501         switch (op) {
3502         case CEPH_SESSION_OPEN:
3503                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3504                         pr_info("mds%d reconnect success\n", session->s_mds);
3505                 session->s_state = CEPH_MDS_SESSION_OPEN;
3506                 session->s_features = features;
3507                 renewed_caps(mdsc, session, 0);
3508                 if (test_bit(CEPHFS_FEATURE_METRIC_COLLECT, &session->s_features))
3509                         metric_schedule_delayed(&mdsc->metric);
3510                 wake = 1;
3511                 if (mdsc->stopping)
3512                         __close_session(mdsc, session);
3513                 break;
3514
3515         case CEPH_SESSION_RENEWCAPS:
3516                 if (session->s_renew_seq == seq)
3517                         renewed_caps(mdsc, session, 1);
3518                 break;
3519
3520         case CEPH_SESSION_CLOSE:
3521                 if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
3522                         pr_info("mds%d reconnect denied\n", session->s_mds);
3523                 session->s_state = CEPH_MDS_SESSION_CLOSED;
3524                 cleanup_session_requests(mdsc, session);
3525                 remove_session_caps(session);
3526                 wake = 2; /* for good measure */
3527                 wake_up_all(&mdsc->session_close_wq);
3528                 break;
3529
3530         case CEPH_SESSION_STALE:
3531                 pr_info("mds%d caps went stale, renewing\n",
3532                         session->s_mds);
3533                 atomic_inc(&session->s_cap_gen);
3534                 session->s_cap_ttl = jiffies - 1;
3535                 send_renew_caps(mdsc, session);
3536                 break;
3537
3538         case CEPH_SESSION_RECALL_STATE:
3539                 ceph_trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
3540                 break;
3541
3542         case CEPH_SESSION_FLUSHMSG:
3543                 send_flushmsg_ack(mdsc, session, seq);
3544                 break;
3545
3546         case CEPH_SESSION_FORCE_RO:
3547                 dout("force_session_readonly %p\n", session);
3548                 spin_lock(&session->s_cap_lock);
3549                 session->s_readonly = true;
3550                 spin_unlock(&session->s_cap_lock);
3551                 wake_up_session_caps(session, FORCE_RO);
3552                 break;
3553
3554         case CEPH_SESSION_REJECT:
3555                 WARN_ON(session->s_state != CEPH_MDS_SESSION_OPENING);
3556                 pr_info("mds%d rejected session\n", session->s_mds);
3557                 session->s_state = CEPH_MDS_SESSION_REJECTED;
3558                 cleanup_session_requests(mdsc, session);
3559                 remove_session_caps(session);
3560                 if (blocklisted)
3561                         mdsc->fsc->blocklisted = true;
3562                 wake = 2; /* for good measure */
3563                 break;
3564
3565         default:
3566                 pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
3567                 WARN_ON(1);
3568         }
3569
3570         mutex_unlock(&session->s_mutex);
3571         if (wake) {
3572                 mutex_lock(&mdsc->mutex);
3573                 __wake_requests(mdsc, &session->s_waiting);
3574                 if (wake == 2)
3575                         kick_requests(mdsc, mds);
3576                 mutex_unlock(&mdsc->mutex);
3577         }
3578         if (op == CEPH_SESSION_CLOSE)
3579                 ceph_put_mds_session(session);
3580         return;
3581
3582 bad:
3583         pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
3584                (int)msg->front.iov_len);
3585         ceph_msg_dump(msg);
3586         return;
3587 }
3588
3589 void ceph_mdsc_release_dir_caps(struct ceph_mds_request *req)
3590 {
3591         int dcaps;
3592
3593         dcaps = xchg(&req->r_dir_caps, 0);
3594         if (dcaps) {
3595                 dout("releasing r_dir_caps=%s\n", ceph_cap_string(dcaps));
3596                 ceph_put_cap_refs(ceph_inode(req->r_parent), dcaps);
3597         }
3598 }
3599
3600 void ceph_mdsc_release_dir_caps_no_check(struct ceph_mds_request *req)
3601 {
3602         int dcaps;
3603
3604         dcaps = xchg(&req->r_dir_caps, 0);
3605         if (dcaps) {
3606                 dout("releasing r_dir_caps=%s\n", ceph_cap_string(dcaps));
3607                 ceph_put_cap_refs_no_check_caps(ceph_inode(req->r_parent),
3608                                                 dcaps);
3609         }
3610 }
3611
3612 /*
3613  * called under session->mutex.
3614  */
3615 static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
3616                                    struct ceph_mds_session *session)
3617 {
3618         struct ceph_mds_request *req, *nreq;
3619         struct rb_node *p;
3620
3621         dout("replay_unsafe_requests mds%d\n", session->s_mds);
3622
3623         mutex_lock(&mdsc->mutex);
3624         list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item)
3625                 __send_request(session, req, true);
3626
3627         /*
3628          * also re-send old requests when MDS enters reconnect stage. So that MDS
3629          * can process completed request in clientreplay stage.
3630          */
3631         p = rb_first(&mdsc->request_tree);
3632         while (p) {
3633                 req = rb_entry(p, struct ceph_mds_request, r_node);
3634                 p = rb_next(p);
3635                 if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags))
3636                         continue;
3637                 if (req->r_attempts == 0)
3638                         continue; /* only old requests */
3639                 if (!req->r_session)
3640                         continue;
3641                 if (req->r_session->s_mds != session->s_mds)
3642                         continue;
3643
3644                 ceph_mdsc_release_dir_caps_no_check(req);
3645
3646                 __send_request(session, req, true);
3647         }
3648         mutex_unlock(&mdsc->mutex);
3649 }
3650
3651 static int send_reconnect_partial(struct ceph_reconnect_state *recon_state)
3652 {
3653         struct ceph_msg *reply;
3654         struct ceph_pagelist *_pagelist;
3655         struct page *page;
3656         __le32 *addr;
3657         int err = -ENOMEM;
3658
3659         if (!recon_state->allow_multi)
3660                 return -ENOSPC;
3661
3662         /* can't handle message that contains both caps and realm */
3663         BUG_ON(!recon_state->nr_caps == !recon_state->nr_realms);
3664
3665         /* pre-allocate new pagelist */
3666         _pagelist = ceph_pagelist_alloc(GFP_NOFS);
3667         if (!_pagelist)
3668                 return -ENOMEM;
3669
3670         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
3671         if (!reply)
3672                 goto fail_msg;
3673
3674         /* placeholder for nr_caps */
3675         err = ceph_pagelist_encode_32(_pagelist, 0);
3676         if (err < 0)
3677                 goto fail;
3678
3679         if (recon_state->nr_caps) {
3680                 /* currently encoding caps */
3681                 err = ceph_pagelist_encode_32(recon_state->pagelist, 0);
3682                 if (err)
3683                         goto fail;
3684         } else {
3685                 /* placeholder for nr_realms (currently encoding relams) */
3686                 err = ceph_pagelist_encode_32(_pagelist, 0);
3687                 if (err < 0)
3688                         goto fail;
3689         }
3690
3691         err = ceph_pagelist_encode_8(recon_state->pagelist, 1);
3692         if (err)
3693                 goto fail;
3694
3695         page = list_first_entry(&recon_state->pagelist->head, struct page, lru);
3696         addr = kmap_atomic(page);
3697         if (recon_state->nr_caps) {
3698                 /* currently encoding caps */
3699                 *addr = cpu_to_le32(recon_state->nr_caps);
3700         } else {
3701                 /* currently encoding relams */
3702                 *(addr + 1) = cpu_to_le32(recon_state->nr_realms);
3703         }
3704         kunmap_atomic(addr);
3705
3706         reply->hdr.version = cpu_to_le16(5);
3707         reply->hdr.compat_version = cpu_to_le16(4);
3708
3709         reply->hdr.data_len = cpu_to_le32(recon_state->pagelist->length);
3710         ceph_msg_data_add_pagelist(reply, recon_state->pagelist);
3711
3712         ceph_con_send(&recon_state->session->s_con, reply);
3713         ceph_pagelist_release(recon_state->pagelist);
3714
3715         recon_state->pagelist = _pagelist;
3716         recon_state->nr_caps = 0;
3717         recon_state->nr_realms = 0;
3718         recon_state->msg_version = 5;
3719         return 0;
3720 fail:
3721         ceph_msg_put(reply);
3722 fail_msg:
3723         ceph_pagelist_release(_pagelist);
3724         return err;
3725 }
3726
3727 static struct dentry* d_find_primary(struct inode *inode)
3728 {
3729         struct dentry *alias, *dn = NULL;
3730
3731         if (hlist_empty(&inode->i_dentry))
3732                 return NULL;
3733
3734         spin_lock(&inode->i_lock);
3735         if (hlist_empty(&inode->i_dentry))
3736                 goto out_unlock;
3737
3738         if (S_ISDIR(inode->i_mode)) {
3739                 alias = hlist_entry(inode->i_dentry.first, struct dentry, d_u.d_alias);
3740                 if (!IS_ROOT(alias))
3741                         dn = dget(alias);
3742                 goto out_unlock;
3743         }
3744
3745         hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
3746                 spin_lock(&alias->d_lock);
3747                 if (!d_unhashed(alias) &&
3748                     (ceph_dentry(alias)->flags & CEPH_DENTRY_PRIMARY_LINK)) {
3749                         dn = dget_dlock(alias);
3750                 }
3751                 spin_unlock(&alias->d_lock);
3752                 if (dn)
3753                         break;
3754         }
3755 out_unlock:
3756         spin_unlock(&inode->i_lock);
3757         return dn;
3758 }
3759
3760 /*
3761  * Encode information about a cap for a reconnect with the MDS.
3762  */
3763 static int reconnect_caps_cb(struct inode *inode, struct ceph_cap *cap,
3764                           void *arg)
3765 {
3766         union {
3767                 struct ceph_mds_cap_reconnect v2;
3768                 struct ceph_mds_cap_reconnect_v1 v1;
3769         } rec;
3770         struct ceph_inode_info *ci = cap->ci;
3771         struct ceph_reconnect_state *recon_state = arg;
3772         struct ceph_pagelist *pagelist = recon_state->pagelist;
3773         struct dentry *dentry;
3774         char *path;
3775         int pathlen, err;
3776         u64 pathbase;
3777         u64 snap_follows;
3778
3779         dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
3780              inode, ceph_vinop(inode), cap, cap->cap_id,
3781              ceph_cap_string(cap->issued));
3782
3783         dentry = d_find_primary(inode);
3784         if (dentry) {
3785                 /* set pathbase to parent dir when msg_version >= 2 */
3786                 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase,
3787                                             recon_state->msg_version >= 2);
3788                 dput(dentry);
3789                 if (IS_ERR(path)) {
3790                         err = PTR_ERR(path);
3791                         goto out_err;
3792                 }
3793         } else {
3794                 path = NULL;
3795                 pathlen = 0;
3796                 pathbase = 0;
3797         }
3798
3799         spin_lock(&ci->i_ceph_lock);
3800         cap->seq = 0;        /* reset cap seq */
3801         cap->issue_seq = 0;  /* and issue_seq */
3802         cap->mseq = 0;       /* and migrate_seq */
3803         cap->cap_gen = atomic_read(&cap->session->s_cap_gen);
3804
3805         /* These are lost when the session goes away */
3806         if (S_ISDIR(inode->i_mode)) {
3807                 if (cap->issued & CEPH_CAP_DIR_CREATE) {
3808                         ceph_put_string(rcu_dereference_raw(ci->i_cached_layout.pool_ns));
3809                         memset(&ci->i_cached_layout, 0, sizeof(ci->i_cached_layout));
3810                 }
3811                 cap->issued &= ~CEPH_CAP_ANY_DIR_OPS;
3812         }
3813
3814         if (recon_state->msg_version >= 2) {
3815                 rec.v2.cap_id = cpu_to_le64(cap->cap_id);
3816                 rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3817                 rec.v2.issued = cpu_to_le32(cap->issued);
3818                 rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3819                 rec.v2.pathbase = cpu_to_le64(pathbase);
3820                 rec.v2.flock_len = (__force __le32)
3821                         ((ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) ? 0 : 1);
3822         } else {
3823                 rec.v1.cap_id = cpu_to_le64(cap->cap_id);
3824                 rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
3825                 rec.v1.issued = cpu_to_le32(cap->issued);
3826                 rec.v1.size = cpu_to_le64(i_size_read(inode));
3827                 ceph_encode_timespec64(&rec.v1.mtime, &inode->i_mtime);
3828                 ceph_encode_timespec64(&rec.v1.atime, &inode->i_atime);
3829                 rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
3830                 rec.v1.pathbase = cpu_to_le64(pathbase);
3831         }
3832
3833         if (list_empty(&ci->i_cap_snaps)) {
3834                 snap_follows = ci->i_head_snapc ? ci->i_head_snapc->seq : 0;
3835         } else {
3836                 struct ceph_cap_snap *capsnap =
3837                         list_first_entry(&ci->i_cap_snaps,
3838                                          struct ceph_cap_snap, ci_item);
3839                 snap_follows = capsnap->follows;
3840         }
3841         spin_unlock(&ci->i_ceph_lock);
3842
3843         if (recon_state->msg_version >= 2) {
3844                 int num_fcntl_locks, num_flock_locks;
3845                 struct ceph_filelock *flocks = NULL;
3846                 size_t struct_len, total_len = sizeof(u64);
3847                 u8 struct_v = 0;
3848
3849 encode_again:
3850                 if (rec.v2.flock_len) {
3851                         ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
3852                 } else {
3853                         num_fcntl_locks = 0;
3854                         num_flock_locks = 0;
3855                 }
3856                 if (num_fcntl_locks + num_flock_locks > 0) {
3857                         flocks = kmalloc_array(num_fcntl_locks + num_flock_locks,
3858                                                sizeof(struct ceph_filelock),
3859                                                GFP_NOFS);
3860                         if (!flocks) {
3861                                 err = -ENOMEM;
3862                                 goto out_err;
3863                         }
3864                         err = ceph_encode_locks_to_buffer(inode, flocks,
3865                                                           num_fcntl_locks,
3866                                                           num_flock_locks);
3867                         if (err) {
3868                                 kfree(flocks);
3869                                 flocks = NULL;
3870                                 if (err == -ENOSPC)
3871                                         goto encode_again;
3872                                 goto out_err;
3873                         }
3874                 } else {
3875                         kfree(flocks);
3876                         flocks = NULL;
3877                 }
3878
3879                 if (recon_state->msg_version >= 3) {
3880                         /* version, compat_version and struct_len */
3881                         total_len += 2 * sizeof(u8) + sizeof(u32);
3882                         struct_v = 2;
3883                 }
3884                 /*
3885                  * number of encoded locks is stable, so copy to pagelist
3886                  */
3887                 struct_len = 2 * sizeof(u32) +
3888                             (num_fcntl_locks + num_flock_locks) *
3889                             sizeof(struct ceph_filelock);
3890                 rec.v2.flock_len = cpu_to_le32(struct_len);
3891
3892                 struct_len += sizeof(u32) + pathlen + sizeof(rec.v2);
3893
3894                 if (struct_v >= 2)
3895                         struct_len += sizeof(u64); /* snap_follows */
3896
3897                 total_len += struct_len;
3898
3899                 if (pagelist->length + total_len > RECONNECT_MAX_SIZE) {
3900                         err = send_reconnect_partial(recon_state);
3901                         if (err)
3902                                 goto out_freeflocks;
3903                         pagelist = recon_state->pagelist;
3904                 }
3905
3906                 err = ceph_pagelist_reserve(pagelist, total_len);
3907                 if (err)
3908                         goto out_freeflocks;
3909
3910                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3911                 if (recon_state->msg_version >= 3) {
3912                         ceph_pagelist_encode_8(pagelist, struct_v);
3913                         ceph_pagelist_encode_8(pagelist, 1);
3914                         ceph_pagelist_encode_32(pagelist, struct_len);
3915                 }
3916                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3917                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v2));
3918                 ceph_locks_to_pagelist(flocks, pagelist,
3919                                        num_fcntl_locks, num_flock_locks);
3920                 if (struct_v >= 2)
3921                         ceph_pagelist_encode_64(pagelist, snap_follows);
3922 out_freeflocks:
3923                 kfree(flocks);
3924         } else {
3925                 err = ceph_pagelist_reserve(pagelist,
3926                                             sizeof(u64) + sizeof(u32) +
3927                                             pathlen + sizeof(rec.v1));
3928                 if (err)
3929                         goto out_err;
3930
3931                 ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
3932                 ceph_pagelist_encode_string(pagelist, path, pathlen);
3933                 ceph_pagelist_append(pagelist, &rec, sizeof(rec.v1));
3934         }
3935
3936 out_err:
3937         ceph_mdsc_free_path(path, pathlen);
3938         if (!err)
3939                 recon_state->nr_caps++;
3940         return err;
3941 }
3942
3943 static int encode_snap_realms(struct ceph_mds_client *mdsc,
3944                               struct ceph_reconnect_state *recon_state)
3945 {
3946         struct rb_node *p;
3947         struct ceph_pagelist *pagelist = recon_state->pagelist;
3948         int err = 0;
3949
3950         if (recon_state->msg_version >= 4) {
3951                 err = ceph_pagelist_encode_32(pagelist, mdsc->num_snap_realms);
3952                 if (err < 0)
3953                         goto fail;
3954         }
3955
3956         /*
3957          * snaprealms.  we provide mds with the ino, seq (version), and
3958          * parent for all of our realms.  If the mds has any newer info,
3959          * it will tell us.
3960          */
3961         for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
3962                 struct ceph_snap_realm *realm =
3963                        rb_entry(p, struct ceph_snap_realm, node);
3964                 struct ceph_mds_snaprealm_reconnect sr_rec;
3965
3966                 if (recon_state->msg_version >= 4) {
3967                         size_t need = sizeof(u8) * 2 + sizeof(u32) +
3968                                       sizeof(sr_rec);
3969
3970                         if (pagelist->length + need > RECONNECT_MAX_SIZE) {
3971                                 err = send_reconnect_partial(recon_state);
3972                                 if (err)
3973                                         goto fail;
3974                                 pagelist = recon_state->pagelist;
3975                         }
3976
3977                         err = ceph_pagelist_reserve(pagelist, need);
3978                         if (err)
3979                                 goto fail;
3980
3981                         ceph_pagelist_encode_8(pagelist, 1);
3982                         ceph_pagelist_encode_8(pagelist, 1);
3983                         ceph_pagelist_encode_32(pagelist, sizeof(sr_rec));
3984                 }
3985
3986                 dout(" adding snap realm %llx seq %lld parent %llx\n",
3987                      realm->ino, realm->seq, realm->parent_ino);
3988                 sr_rec.ino = cpu_to_le64(realm->ino);
3989                 sr_rec.seq = cpu_to_le64(realm->seq);
3990                 sr_rec.parent = cpu_to_le64(realm->parent_ino);
3991
3992                 err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
3993                 if (err)
3994                         goto fail;
3995
3996                 recon_state->nr_realms++;
3997         }
3998 fail:
3999         return err;
4000 }
4001
4002
4003 /*
4004  * If an MDS fails and recovers, clients need to reconnect in order to
4005  * reestablish shared state.  This includes all caps issued through
4006  * this session _and_ the snap_realm hierarchy.  Because it's not
4007  * clear which snap realms the mds cares about, we send everything we
4008  * know about.. that ensures we'll then get any new info the
4009  * recovering MDS might have.
4010  *
4011  * This is a relatively heavyweight operation, but it's rare.
4012  */
4013 static void send_mds_reconnect(struct ceph_mds_client *mdsc,
4014                                struct ceph_mds_session *session)
4015 {
4016         struct ceph_msg *reply;
4017         int mds = session->s_mds;
4018         int err = -ENOMEM;
4019         struct ceph_reconnect_state recon_state = {
4020                 .session = session,
4021         };
4022         LIST_HEAD(dispose);
4023
4024         pr_info("mds%d reconnect start\n", mds);
4025
4026         recon_state.pagelist = ceph_pagelist_alloc(GFP_NOFS);
4027         if (!recon_state.pagelist)
4028                 goto fail_nopagelist;
4029
4030         reply = ceph_msg_new2(CEPH_MSG_CLIENT_RECONNECT, 0, 1, GFP_NOFS, false);
4031         if (!reply)
4032                 goto fail_nomsg;
4033
4034         xa_destroy(&session->s_delegated_inos);
4035
4036         mutex_lock(&session->s_mutex);
4037         session->s_state = CEPH_MDS_SESSION_RECONNECTING;
4038         session->s_seq = 0;
4039
4040         dout("session %p state %s\n", session,
4041              ceph_session_state_name(session->s_state));
4042
4043         atomic_inc(&session->s_cap_gen);
4044
4045         spin_lock(&session->s_cap_lock);
4046         /* don't know if session is readonly */
4047         session->s_readonly = 0;
4048         /*
4049          * notify __ceph_remove_cap() that we are composing cap reconnect.
4050          * If a cap get released before being added to the cap reconnect,
4051          * __ceph_remove_cap() should skip queuing cap release.
4052          */
4053         session->s_cap_reconnect = 1;
4054         /* drop old cap expires; we're about to reestablish that state */
4055         detach_cap_releases(session, &dispose);
4056         spin_unlock(&session->s_cap_lock);
4057         dispose_cap_releases(mdsc, &dispose);
4058
4059         /* trim unused caps to reduce MDS's cache rejoin time */
4060         if (mdsc->fsc->sb->s_root)
4061                 shrink_dcache_parent(mdsc->fsc->sb->s_root);
4062
4063         ceph_con_close(&session->s_con);
4064         ceph_con_open(&session->s_con,
4065                       CEPH_ENTITY_TYPE_MDS, mds,
4066                       ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
4067
4068         /* replay unsafe requests */
4069         replay_unsafe_requests(mdsc, session);
4070
4071         ceph_early_kick_flushing_caps(mdsc, session);
4072
4073         down_read(&mdsc->snap_rwsem);
4074
4075         /* placeholder for nr_caps */
4076         err = ceph_pagelist_encode_32(recon_state.pagelist, 0);
4077         if (err)
4078                 goto fail;
4079
4080         if (test_bit(CEPHFS_FEATURE_MULTI_RECONNECT, &session->s_features)) {
4081                 recon_state.msg_version = 3;
4082                 recon_state.allow_multi = true;
4083         } else if (session->s_con.peer_features & CEPH_FEATURE_MDSENC) {
4084                 recon_state.msg_version = 3;
4085         } else {
4086                 recon_state.msg_version = 2;
4087         }
4088         /* trsaverse this session's caps */
4089         err = ceph_iterate_session_caps(session, reconnect_caps_cb, &recon_state);
4090
4091         spin_lock(&session->s_cap_lock);
4092         session->s_cap_reconnect = 0;
4093         spin_unlock(&session->s_cap_lock);
4094
4095         if (err < 0)
4096                 goto fail;
4097
4098         /* check if all realms can be encoded into current message */
4099         if (mdsc->num_snap_realms) {
4100                 size_t total_len =
4101                         recon_state.pagelist->length +
4102                         mdsc->num_snap_realms *
4103                         sizeof(struct ceph_mds_snaprealm_reconnect);
4104                 if (recon_state.msg_version >= 4) {
4105                         /* number of realms */
4106                         total_len += sizeof(u32);
4107                         /* version, compat_version and struct_len */
4108                         total_len += mdsc->num_snap_realms *
4109                                      (2 * sizeof(u8) + sizeof(u32));
4110                 }
4111                 if (total_len > RECONNECT_MAX_SIZE) {
4112                         if (!recon_state.allow_multi) {
4113                                 err = -ENOSPC;
4114                                 goto fail;
4115                         }
4116                         if (recon_state.nr_caps) {
4117                                 err = send_reconnect_partial(&recon_state);
4118                                 if (err)
4119                                         goto fail;
4120                         }
4121                         recon_state.msg_version = 5;
4122                 }
4123         }
4124
4125         err = encode_snap_realms(mdsc, &recon_state);
4126         if (err < 0)
4127                 goto fail;
4128
4129         if (recon_state.msg_version >= 5) {
4130                 err = ceph_pagelist_encode_8(recon_state.pagelist, 0);
4131                 if (err < 0)
4132                         goto fail;
4133         }
4134
4135         if (recon_state.nr_caps || recon_state.nr_realms) {
4136                 struct page *page =
4137                         list_first_entry(&recon_state.pagelist->head,
4138                                         struct page, lru);
4139                 __le32 *addr = kmap_atomic(page);
4140                 if (recon_state.nr_caps) {
4141                         WARN_ON(recon_state.nr_realms != mdsc->num_snap_realms);
4142                         *addr = cpu_to_le32(recon_state.nr_caps);
4143                 } else if (recon_state.msg_version >= 4) {
4144                         *(addr + 1) = cpu_to_le32(recon_state.nr_realms);
4145                 }
4146                 kunmap_atomic(addr);
4147         }
4148
4149         reply->hdr.version = cpu_to_le16(recon_state.msg_version);
4150         if (recon_state.msg_version >= 4)
4151                 reply->hdr.compat_version = cpu_to_le16(4);
4152
4153         reply->hdr.data_len = cpu_to_le32(recon_state.pagelist->length);
4154         ceph_msg_data_add_pagelist(reply, recon_state.pagelist);
4155
4156         ceph_con_send(&session->s_con, reply);
4157
4158         mutex_unlock(&session->s_mutex);
4159
4160         mutex_lock(&mdsc->mutex);
4161         __wake_requests(mdsc, &session->s_waiting);
4162         mutex_unlock(&mdsc->mutex);
4163
4164         up_read(&mdsc->snap_rwsem);
4165         ceph_pagelist_release(recon_state.pagelist);
4166         return;
4167
4168 fail:
4169         ceph_msg_put(reply);
4170         up_read(&mdsc->snap_rwsem);
4171         mutex_unlock(&session->s_mutex);
4172 fail_nomsg:
4173         ceph_pagelist_release(recon_state.pagelist);
4174 fail_nopagelist:
4175         pr_err("error %d preparing reconnect for mds%d\n", err, mds);
4176         return;
4177 }
4178
4179
4180 /*
4181  * compare old and new mdsmaps, kicking requests
4182  * and closing out old connections as necessary
4183  *
4184  * called under mdsc->mutex.
4185  */
4186 static void check_new_map(struct ceph_mds_client *mdsc,
4187                           struct ceph_mdsmap *newmap,
4188                           struct ceph_mdsmap *oldmap)
4189 {
4190         int i, j, err;
4191         int oldstate, newstate;
4192         struct ceph_mds_session *s;
4193         unsigned long targets[DIV_ROUND_UP(CEPH_MAX_MDS, sizeof(unsigned long))] = {0};
4194
4195         dout("check_new_map new %u old %u\n",
4196              newmap->m_epoch, oldmap->m_epoch);
4197
4198         if (newmap->m_info) {
4199                 for (i = 0; i < newmap->possible_max_rank; i++) {
4200                         for (j = 0; j < newmap->m_info[i].num_export_targets; j++)
4201                                 set_bit(newmap->m_info[i].export_targets[j], targets);
4202                 }
4203         }
4204
4205         for (i = 0; i < oldmap->possible_max_rank && i < mdsc->max_sessions; i++) {
4206                 if (!mdsc->sessions[i])
4207                         continue;
4208                 s = mdsc->sessions[i];
4209                 oldstate = ceph_mdsmap_get_state(oldmap, i);
4210                 newstate = ceph_mdsmap_get_state(newmap, i);
4211
4212                 dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
4213                      i, ceph_mds_state_name(oldstate),
4214                      ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
4215                      ceph_mds_state_name(newstate),
4216                      ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
4217                      ceph_session_state_name(s->s_state));
4218
4219                 if (i >= newmap->possible_max_rank) {
4220                         /* force close session for stopped mds */
4221                         ceph_get_mds_session(s);
4222                         __unregister_session(mdsc, s);
4223                         __wake_requests(mdsc, &s->s_waiting);
4224                         mutex_unlock(&mdsc->mutex);
4225
4226                         mutex_lock(&s->s_mutex);
4227                         cleanup_session_requests(mdsc, s);
4228                         remove_session_caps(s);
4229                         mutex_unlock(&s->s_mutex);
4230
4231                         ceph_put_mds_session(s);
4232
4233                         mutex_lock(&mdsc->mutex);
4234                         kick_requests(mdsc, i);
4235                         continue;
4236                 }
4237
4238                 if (memcmp(ceph_mdsmap_get_addr(oldmap, i),
4239                            ceph_mdsmap_get_addr(newmap, i),
4240                            sizeof(struct ceph_entity_addr))) {
4241                         /* just close it */
4242                         mutex_unlock(&mdsc->mutex);
4243                         mutex_lock(&s->s_mutex);
4244                         mutex_lock(&mdsc->mutex);
4245                         ceph_con_close(&s->s_con);
4246                         mutex_unlock(&s->s_mutex);
4247                         s->s_state = CEPH_MDS_SESSION_RESTARTING;
4248                 } else if (oldstate == newstate) {
4249                         continue;  /* nothing new with this mds */
4250                 }
4251
4252                 /*
4253                  * send reconnect?
4254                  */
4255                 if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
4256                     newstate >= CEPH_MDS_STATE_RECONNECT) {
4257                         mutex_unlock(&mdsc->mutex);
4258                         clear_bit(i, targets);
4259                         send_mds_reconnect(mdsc, s);
4260                         mutex_lock(&mdsc->mutex);
4261                 }
4262
4263                 /*
4264                  * kick request on any mds that has gone active.
4265                  */
4266                 if (oldstate < CEPH_MDS_STATE_ACTIVE &&
4267                     newstate >= CEPH_MDS_STATE_ACTIVE) {
4268                         if (oldstate != CEPH_MDS_STATE_CREATING &&
4269                             oldstate != CEPH_MDS_STATE_STARTING)
4270                                 pr_info("mds%d recovery completed\n", s->s_mds);
4271                         kick_requests(mdsc, i);
4272                         mutex_unlock(&mdsc->mutex);
4273                         mutex_lock(&s->s_mutex);
4274                         mutex_lock(&mdsc->mutex);
4275                         ceph_kick_flushing_caps(mdsc, s);
4276                         mutex_unlock(&s->s_mutex);
4277                         wake_up_session_caps(s, RECONNECT);
4278                 }
4279         }
4280
4281         /*
4282          * Only open and reconnect sessions that don't exist yet.
4283          */
4284         for (i = 0; i < newmap->possible_max_rank; i++) {
4285                 /*
4286                  * In case the import MDS is crashed just after
4287                  * the EImportStart journal is flushed, so when
4288                  * a standby MDS takes over it and is replaying
4289                  * the EImportStart journal the new MDS daemon
4290                  * will wait the client to reconnect it, but the
4291                  * client may never register/open the session yet.
4292                  *
4293                  * Will try to reconnect that MDS daemon if the
4294                  * rank number is in the export targets array and
4295                  * is the up:reconnect state.
4296                  */
4297                 newstate = ceph_mdsmap_get_state(newmap, i);
4298                 if (!test_bit(i, targets) || newstate != CEPH_MDS_STATE_RECONNECT)
4299                         continue;
4300
4301                 /*
4302                  * The session maybe registered and opened by some
4303                  * requests which were choosing random MDSes during
4304                  * the mdsc->mutex's unlock/lock gap below in rare
4305                  * case. But the related MDS daemon will just queue
4306                  * that requests and be still waiting for the client's
4307                  * reconnection request in up:reconnect state.
4308                  */
4309                 s = __ceph_lookup_mds_session(mdsc, i);
4310                 if (likely(!s)) {
4311                         s = __open_export_target_session(mdsc, i);
4312                         if (IS_ERR(s)) {
4313                                 err = PTR_ERR(s);
4314                                 pr_err("failed to open export target session, err %d\n",
4315                                        err);
4316                                 continue;
4317                         }
4318                 }
4319                 dout("send reconnect to export target mds.%d\n", i);
4320                 mutex_unlock(&mdsc->mutex);
4321                 send_mds_reconnect(mdsc, s);
4322                 ceph_put_mds_session(s);
4323                 mutex_lock(&mdsc->mutex);
4324         }
4325
4326         for (i = 0; i < newmap->possible_max_rank && i < mdsc->max_sessions; i++) {
4327                 s = mdsc->sessions[i];
4328                 if (!s)
4329                         continue;
4330                 if (!ceph_mdsmap_is_laggy(newmap, i))
4331                         continue;
4332                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4333                     s->s_state == CEPH_MDS_SESSION_HUNG ||
4334                     s->s_state == CEPH_MDS_SESSION_CLOSING) {
4335                         dout(" connecting to export targets of laggy mds%d\n",
4336                              i);
4337                         __open_export_target_sessions(mdsc, s);
4338                 }
4339         }
4340 }
4341
4342
4343
4344 /*
4345  * leases
4346  */
4347
4348 /*
4349  * caller must hold session s_mutex, dentry->d_lock
4350  */
4351 void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
4352 {
4353         struct ceph_dentry_info *di = ceph_dentry(dentry);
4354
4355         ceph_put_mds_session(di->lease_session);
4356         di->lease_session = NULL;
4357 }
4358
4359 static void handle_lease(struct ceph_mds_client *mdsc,
4360                          struct ceph_mds_session *session,
4361                          struct ceph_msg *msg)
4362 {
4363         struct super_block *sb = mdsc->fsc->sb;
4364         struct inode *inode;
4365         struct dentry *parent, *dentry;
4366         struct ceph_dentry_info *di;
4367         int mds = session->s_mds;
4368         struct ceph_mds_lease *h = msg->front.iov_base;
4369         u32 seq;
4370         struct ceph_vino vino;
4371         struct qstr dname;
4372         int release = 0;
4373
4374         dout("handle_lease from mds%d\n", mds);
4375
4376         /* decode */
4377         if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
4378                 goto bad;
4379         vino.ino = le64_to_cpu(h->ino);
4380         vino.snap = CEPH_NOSNAP;
4381         seq = le32_to_cpu(h->seq);
4382         dname.len = get_unaligned_le32(h + 1);
4383         if (msg->front.iov_len < sizeof(*h) + sizeof(u32) + dname.len)
4384                 goto bad;
4385         dname.name = (void *)(h + 1) + sizeof(u32);
4386
4387         /* lookup inode */
4388         inode = ceph_find_inode(sb, vino);
4389         dout("handle_lease %s, ino %llx %p %.*s\n",
4390              ceph_lease_op_name(h->action), vino.ino, inode,
4391              dname.len, dname.name);
4392
4393         mutex_lock(&session->s_mutex);
4394         inc_session_sequence(session);
4395
4396         if (!inode) {
4397                 dout("handle_lease no inode %llx\n", vino.ino);
4398                 goto release;
4399         }
4400
4401         /* dentry */
4402         parent = d_find_alias(inode);
4403         if (!parent) {
4404                 dout("no parent dentry on inode %p\n", inode);
4405                 WARN_ON(1);
4406                 goto release;  /* hrm... */
4407         }
4408         dname.hash = full_name_hash(parent, dname.name, dname.len);
4409         dentry = d_lookup(parent, &dname);
4410         dput(parent);
4411         if (!dentry)
4412                 goto release;
4413
4414         spin_lock(&dentry->d_lock);
4415         di = ceph_dentry(dentry);
4416         switch (h->action) {
4417         case CEPH_MDS_LEASE_REVOKE:
4418                 if (di->lease_session == session) {
4419                         if (ceph_seq_cmp(di->lease_seq, seq) > 0)
4420                                 h->seq = cpu_to_le32(di->lease_seq);
4421                         __ceph_mdsc_drop_dentry_lease(dentry);
4422                 }
4423                 release = 1;
4424                 break;
4425
4426         case CEPH_MDS_LEASE_RENEW:
4427                 if (di->lease_session == session &&
4428                     di->lease_gen == atomic_read(&session->s_cap_gen) &&
4429                     di->lease_renew_from &&
4430                     di->lease_renew_after == 0) {
4431                         unsigned long duration =
4432                                 msecs_to_jiffies(le32_to_cpu(h->duration_ms));
4433
4434                         di->lease_seq = seq;
4435                         di->time = di->lease_renew_from + duration;
4436                         di->lease_renew_after = di->lease_renew_from +
4437                                 (duration >> 1);
4438                         di->lease_renew_from = 0;
4439                 }
4440                 break;
4441         }
4442         spin_unlock(&dentry->d_lock);
4443         dput(dentry);
4444
4445         if (!release)
4446                 goto out;
4447
4448 release:
4449         /* let's just reuse the same message */
4450         h->action = CEPH_MDS_LEASE_REVOKE_ACK;
4451         ceph_msg_get(msg);
4452         ceph_con_send(&session->s_con, msg);
4453
4454 out:
4455         mutex_unlock(&session->s_mutex);
4456         iput(inode);
4457         return;
4458
4459 bad:
4460         pr_err("corrupt lease message\n");
4461         ceph_msg_dump(msg);
4462 }
4463
4464 void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
4465                               struct dentry *dentry, char action,
4466                               u32 seq)
4467 {
4468         struct ceph_msg *msg;
4469         struct ceph_mds_lease *lease;
4470         struct inode *dir;
4471         int len = sizeof(*lease) + sizeof(u32) + NAME_MAX;
4472
4473         dout("lease_send_msg identry %p %s to mds%d\n",
4474              dentry, ceph_lease_op_name(action), session->s_mds);
4475
4476         msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
4477         if (!msg)
4478                 return;
4479         lease = msg->front.iov_base;
4480         lease->action = action;
4481         lease->seq = cpu_to_le32(seq);
4482
4483         spin_lock(&dentry->d_lock);
4484         dir = d_inode(dentry->d_parent);
4485         lease->ino = cpu_to_le64(ceph_ino(dir));
4486         lease->first = lease->last = cpu_to_le64(ceph_snap(dir));
4487
4488         put_unaligned_le32(dentry->d_name.len, lease + 1);
4489         memcpy((void *)(lease + 1) + 4,
4490                dentry->d_name.name, dentry->d_name.len);
4491         spin_unlock(&dentry->d_lock);
4492         /*
4493          * if this is a preemptive lease RELEASE, no need to
4494          * flush request stream, since the actual request will
4495          * soon follow.
4496          */
4497         msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
4498
4499         ceph_con_send(&session->s_con, msg);
4500 }
4501
4502 /*
4503  * lock unlock the session, to wait ongoing session activities
4504  */
4505 static void lock_unlock_session(struct ceph_mds_session *s)
4506 {
4507         mutex_lock(&s->s_mutex);
4508         mutex_unlock(&s->s_mutex);
4509 }
4510
4511 static void maybe_recover_session(struct ceph_mds_client *mdsc)
4512 {
4513         struct ceph_fs_client *fsc = mdsc->fsc;
4514
4515         if (!ceph_test_mount_opt(fsc, CLEANRECOVER))
4516                 return;
4517
4518         if (READ_ONCE(fsc->mount_state) != CEPH_MOUNT_MOUNTED)
4519                 return;
4520
4521         if (!READ_ONCE(fsc->blocklisted))
4522                 return;
4523
4524         pr_info("auto reconnect after blocklisted\n");
4525         ceph_force_reconnect(fsc->sb);
4526 }
4527
4528 bool check_session_state(struct ceph_mds_session *s)
4529 {
4530         struct ceph_fs_client *fsc = s->s_mdsc->fsc;
4531
4532         switch (s->s_state) {
4533         case CEPH_MDS_SESSION_OPEN:
4534                 if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
4535                         s->s_state = CEPH_MDS_SESSION_HUNG;
4536                         pr_info("mds%d hung\n", s->s_mds);
4537                 }
4538                 break;
4539         case CEPH_MDS_SESSION_CLOSING:
4540                 /* Should never reach this when not force unmounting */
4541                 WARN_ON_ONCE(s->s_ttl &&
4542                              READ_ONCE(fsc->mount_state) != CEPH_MOUNT_SHUTDOWN);
4543                 fallthrough;
4544         case CEPH_MDS_SESSION_NEW:
4545         case CEPH_MDS_SESSION_RESTARTING:
4546         case CEPH_MDS_SESSION_CLOSED:
4547         case CEPH_MDS_SESSION_REJECTED:
4548                 return false;
4549         }
4550
4551         return true;
4552 }
4553
4554 /*
4555  * If the sequence is incremented while we're waiting on a REQUEST_CLOSE reply,
4556  * then we need to retransmit that request.
4557  */
4558 void inc_session_sequence(struct ceph_mds_session *s)
4559 {
4560         lockdep_assert_held(&s->s_mutex);
4561
4562         s->s_seq++;
4563
4564         if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
4565                 int ret;
4566
4567                 dout("resending session close request for mds%d\n", s->s_mds);
4568                 ret = request_close_session(s);
4569                 if (ret < 0)
4570                         pr_err("unable to close session to mds%d: %d\n",
4571                                s->s_mds, ret);
4572         }
4573 }
4574
4575 /*
4576  * delayed work -- periodically trim expired leases, renew caps with mds.  If
4577  * the @delay parameter is set to 0 or if it's more than 5 secs, the default
4578  * workqueue delay value of 5 secs will be used.
4579  */
4580 static void schedule_delayed(struct ceph_mds_client *mdsc, unsigned long delay)
4581 {
4582         unsigned long max_delay = HZ * 5;
4583
4584         /* 5 secs default delay */
4585         if (!delay || (delay > max_delay))
4586                 delay = max_delay;
4587         schedule_delayed_work(&mdsc->delayed_work,
4588                               round_jiffies_relative(delay));
4589 }
4590
4591 static void delayed_work(struct work_struct *work)
4592 {
4593         struct ceph_mds_client *mdsc =
4594                 container_of(work, struct ceph_mds_client, delayed_work.work);
4595         unsigned long delay;
4596         int renew_interval;
4597         int renew_caps;
4598         int i;
4599
4600         dout("mdsc delayed_work\n");
4601
4602         if (mdsc->stopping)
4603                 return;
4604
4605         mutex_lock(&mdsc->mutex);
4606         renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
4607         renew_caps = time_after_eq(jiffies, HZ*renew_interval +
4608                                    mdsc->last_renew_caps);
4609         if (renew_caps)
4610                 mdsc->last_renew_caps = jiffies;
4611
4612         for (i = 0; i < mdsc->max_sessions; i++) {
4613                 struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
4614                 if (!s)
4615                         continue;
4616
4617                 if (!check_session_state(s)) {
4618                         ceph_put_mds_session(s);
4619                         continue;
4620                 }
4621                 mutex_unlock(&mdsc->mutex);
4622
4623                 mutex_lock(&s->s_mutex);
4624                 if (renew_caps)
4625                         send_renew_caps(mdsc, s);
4626                 else
4627                         ceph_con_keepalive(&s->s_con);
4628                 if (s->s_state == CEPH_MDS_SESSION_OPEN ||
4629                     s->s_state == CEPH_MDS_SESSION_HUNG)
4630                         ceph_send_cap_releases(mdsc, s);
4631                 mutex_unlock(&s->s_mutex);
4632                 ceph_put_mds_session(s);
4633
4634                 mutex_lock(&mdsc->mutex);
4635         }
4636         mutex_unlock(&mdsc->mutex);
4637
4638         delay = ceph_check_delayed_caps(mdsc);
4639
4640         ceph_queue_cap_reclaim_work(mdsc);
4641
4642         ceph_trim_snapid_map(mdsc);
4643
4644         maybe_recover_session(mdsc);
4645
4646         schedule_delayed(mdsc, delay);
4647 }
4648
4649 int ceph_mdsc_init(struct ceph_fs_client *fsc)
4650
4651 {
4652         struct ceph_mds_client *mdsc;
4653         int err;
4654
4655         mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
4656         if (!mdsc)
4657                 return -ENOMEM;
4658         mdsc->fsc = fsc;
4659         mutex_init(&mdsc->mutex);
4660         mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
4661         if (!mdsc->mdsmap) {
4662                 err = -ENOMEM;
4663                 goto err_mdsc;
4664         }
4665
4666         init_completion(&mdsc->safe_umount_waiters);
4667         init_waitqueue_head(&mdsc->session_close_wq);
4668         INIT_LIST_HEAD(&mdsc->waiting_for_map);
4669         mdsc->quotarealms_inodes = RB_ROOT;
4670         mutex_init(&mdsc->quotarealms_inodes_mutex);
4671         init_rwsem(&mdsc->snap_rwsem);
4672         mdsc->snap_realms = RB_ROOT;
4673         INIT_LIST_HEAD(&mdsc->snap_empty);
4674         spin_lock_init(&mdsc->snap_empty_lock);
4675         mdsc->request_tree = RB_ROOT;
4676         INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
4677         mdsc->last_renew_caps = jiffies;
4678         INIT_LIST_HEAD(&mdsc->cap_delay_list);
4679         INIT_LIST_HEAD(&mdsc->cap_wait_list);
4680         spin_lock_init(&mdsc->cap_delay_lock);
4681         INIT_LIST_HEAD(&mdsc->snap_flush_list);
4682         spin_lock_init(&mdsc->snap_flush_lock);
4683         mdsc->last_cap_flush_tid = 1;
4684         INIT_LIST_HEAD(&mdsc->cap_flush_list);
4685         INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
4686         spin_lock_init(&mdsc->cap_dirty_lock);
4687         init_waitqueue_head(&mdsc->cap_flushing_wq);
4688         INIT_WORK(&mdsc->cap_reclaim_work, ceph_cap_reclaim_work);
4689         err = ceph_metric_init(&mdsc->metric);
4690         if (err)
4691                 goto err_mdsmap;
4692
4693         spin_lock_init(&mdsc->dentry_list_lock);
4694         INIT_LIST_HEAD(&mdsc->dentry_leases);
4695         INIT_LIST_HEAD(&mdsc->dentry_dir_leases);
4696
4697         ceph_caps_init(mdsc);
4698         ceph_adjust_caps_max_min(mdsc, fsc->mount_options);
4699
4700         spin_lock_init(&mdsc->snapid_map_lock);
4701         mdsc->snapid_map_tree = RB_ROOT;
4702         INIT_LIST_HEAD(&mdsc->snapid_map_lru);
4703
4704         init_rwsem(&mdsc->pool_perm_rwsem);
4705         mdsc->pool_perm_tree = RB_ROOT;
4706
4707         strscpy(mdsc->nodename, utsname()->nodename,
4708                 sizeof(mdsc->nodename));
4709
4710         fsc->mdsc = mdsc;
4711         return 0;
4712
4713 err_mdsmap:
4714         kfree(mdsc->mdsmap);
4715 err_mdsc:
4716         kfree(mdsc);
4717         return err;
4718 }
4719
4720 /*
4721  * Wait for safe replies on open mds requests.  If we time out, drop
4722  * all requests from the tree to avoid dangling dentry refs.
4723  */
4724 static void wait_requests(struct ceph_mds_client *mdsc)
4725 {
4726         struct ceph_options *opts = mdsc->fsc->client->options;
4727         struct ceph_mds_request *req;
4728
4729         mutex_lock(&mdsc->mutex);
4730         if (__get_oldest_req(mdsc)) {
4731                 mutex_unlock(&mdsc->mutex);
4732
4733                 dout("wait_requests waiting for requests\n");
4734                 wait_for_completion_timeout(&mdsc->safe_umount_waiters,
4735                                     ceph_timeout_jiffies(opts->mount_timeout));
4736
4737                 /* tear down remaining requests */
4738                 mutex_lock(&mdsc->mutex);
4739                 while ((req = __get_oldest_req(mdsc))) {
4740                         dout("wait_requests timed out on tid %llu\n",
4741                              req->r_tid);
4742                         list_del_init(&req->r_wait);
4743                         __unregister_request(mdsc, req);
4744                 }
4745         }
4746         mutex_unlock(&mdsc->mutex);
4747         dout("wait_requests done\n");
4748 }
4749
4750 void send_flush_mdlog(struct ceph_mds_session *s)
4751 {
4752         struct ceph_msg *msg;
4753
4754         /*
4755          * Pre-luminous MDS crashes when it sees an unknown session request
4756          */
4757         if (!CEPH_HAVE_FEATURE(s->s_con.peer_features, SERVER_LUMINOUS))
4758                 return;
4759
4760         mutex_lock(&s->s_mutex);
4761         dout("request mdlog flush to mds%d (%s)s seq %lld\n", s->s_mds,
4762              ceph_session_state_name(s->s_state), s->s_seq);
4763         msg = ceph_create_session_msg(CEPH_SESSION_REQUEST_FLUSH_MDLOG,
4764                                       s->s_seq);
4765         if (!msg) {
4766                 pr_err("failed to request mdlog flush to mds%d (%s) seq %lld\n",
4767                        s->s_mds, ceph_session_state_name(s->s_state), s->s_seq);
4768         } else {
4769                 ceph_con_send(&s->s_con, msg);
4770         }
4771         mutex_unlock(&s->s_mutex);
4772 }
4773
4774 /*
4775  * called before mount is ro, and before dentries are torn down.
4776  * (hmm, does this still race with new lookups?)
4777  */
4778 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
4779 {
4780         dout("pre_umount\n");
4781         mdsc->stopping = 1;
4782
4783         ceph_mdsc_iterate_sessions(mdsc, send_flush_mdlog, true);
4784         ceph_mdsc_iterate_sessions(mdsc, lock_unlock_session, false);
4785         ceph_flush_dirty_caps(mdsc);
4786         wait_requests(mdsc);
4787
4788         /*
4789          * wait for reply handlers to drop their request refs and
4790          * their inode/dcache refs
4791          */
4792         ceph_msgr_flush();
4793
4794         ceph_cleanup_quotarealms_inodes(mdsc);
4795 }
4796
4797 /*
4798  * wait for all write mds requests to flush.
4799  */
4800 static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
4801 {
4802         struct ceph_mds_request *req = NULL, *nextreq;
4803         struct rb_node *n;
4804
4805         mutex_lock(&mdsc->mutex);
4806         dout("wait_unsafe_requests want %lld\n", want_tid);
4807 restart:
4808         req = __get_oldest_req(mdsc);
4809         while (req && req->r_tid <= want_tid) {
4810                 /* find next request */
4811                 n = rb_next(&req->r_node);
4812                 if (n)
4813                         nextreq = rb_entry(n, struct ceph_mds_request, r_node);
4814                 else
4815                         nextreq = NULL;
4816                 if (req->r_op != CEPH_MDS_OP_SETFILELOCK &&
4817                     (req->r_op & CEPH_MDS_OP_WRITE)) {
4818                         /* write op */
4819                         ceph_mdsc_get_request(req);
4820                         if (nextreq)
4821                                 ceph_mdsc_get_request(nextreq);
4822                         mutex_unlock(&mdsc->mutex);
4823                         dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
4824                              req->r_tid, want_tid);
4825                         wait_for_completion(&req->r_safe_completion);
4826                         mutex_lock(&mdsc->mutex);
4827                         ceph_mdsc_put_request(req);
4828                         if (!nextreq)
4829                                 break;  /* next dne before, so we're done! */
4830                         if (RB_EMPTY_NODE(&nextreq->r_node)) {
4831                                 /* next request was removed from tree */
4832                                 ceph_mdsc_put_request(nextreq);
4833                                 goto restart;
4834                         }
4835                         ceph_mdsc_put_request(nextreq);  /* won't go away */
4836                 }
4837                 req = nextreq;
4838         }
4839         mutex_unlock(&mdsc->mutex);
4840         dout("wait_unsafe_requests done\n");
4841 }
4842
4843 void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
4844 {
4845         u64 want_tid, want_flush;
4846
4847         if (READ_ONCE(mdsc->fsc->mount_state) >= CEPH_MOUNT_SHUTDOWN)
4848                 return;
4849
4850         dout("sync\n");
4851         mutex_lock(&mdsc->mutex);
4852         want_tid = mdsc->last_tid;
4853         mutex_unlock(&mdsc->mutex);
4854
4855         ceph_flush_dirty_caps(mdsc);
4856         spin_lock(&mdsc->cap_dirty_lock);
4857         want_flush = mdsc->last_cap_flush_tid;
4858         if (!list_empty(&mdsc->cap_flush_list)) {
4859                 struct ceph_cap_flush *cf =
4860                         list_last_entry(&mdsc->cap_flush_list,
4861                                         struct ceph_cap_flush, g_list);
4862                 cf->wake = true;
4863         }
4864         spin_unlock(&mdsc->cap_dirty_lock);
4865
4866         dout("sync want tid %lld flush_seq %lld\n",
4867              want_tid, want_flush);
4868
4869         wait_unsafe_requests(mdsc, want_tid);
4870         wait_caps_flush(mdsc, want_flush);
4871 }
4872
4873 /*
4874  * true if all sessions are closed, or we force unmount
4875  */
4876 static bool done_closing_sessions(struct ceph_mds_client *mdsc, int skipped)
4877 {
4878         if (READ_ONCE(mdsc->fsc->mount_state) == CEPH_MOUNT_SHUTDOWN)
4879                 return true;
4880         return atomic_read(&mdsc->num_sessions) <= skipped;
4881 }
4882
4883 /*
4884  * called after sb is ro.
4885  */
4886 void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
4887 {
4888         struct ceph_options *opts = mdsc->fsc->client->options;
4889         struct ceph_mds_session *session;
4890         int i;
4891         int skipped = 0;
4892
4893         dout("close_sessions\n");
4894
4895         /* close sessions */
4896         mutex_lock(&mdsc->mutex);
4897         for (i = 0; i < mdsc->max_sessions; i++) {
4898                 session = __ceph_lookup_mds_session(mdsc, i);
4899                 if (!session)
4900                         continue;
4901                 mutex_unlock(&mdsc->mutex);
4902                 mutex_lock(&session->s_mutex);
4903                 if (__close_session(mdsc, session) <= 0)
4904                         skipped++;
4905                 mutex_unlock(&session->s_mutex);
4906                 ceph_put_mds_session(session);
4907                 mutex_lock(&mdsc->mutex);
4908         }
4909         mutex_unlock(&mdsc->mutex);
4910
4911         dout("waiting for sessions to close\n");
4912         wait_event_timeout(mdsc->session_close_wq,
4913                            done_closing_sessions(mdsc, skipped),
4914                            ceph_timeout_jiffies(opts->mount_timeout));
4915
4916         /* tear down remaining sessions */
4917         mutex_lock(&mdsc->mutex);
4918         for (i = 0; i < mdsc->max_sessions; i++) {
4919                 if (mdsc->sessions[i]) {
4920                         session = ceph_get_mds_session(mdsc->sessions[i]);
4921                         __unregister_session(mdsc, session);
4922                         mutex_unlock(&mdsc->mutex);
4923                         mutex_lock(&session->s_mutex);
4924                         remove_session_caps(session);
4925                         mutex_unlock(&session->s_mutex);
4926                         ceph_put_mds_session(session);
4927                         mutex_lock(&mdsc->mutex);
4928                 }
4929         }
4930         WARN_ON(!list_empty(&mdsc->cap_delay_list));
4931         mutex_unlock(&mdsc->mutex);
4932
4933         ceph_cleanup_snapid_map(mdsc);
4934         ceph_cleanup_empty_realms(mdsc);
4935
4936         cancel_work_sync(&mdsc->cap_reclaim_work);
4937         cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
4938
4939         dout("stopped\n");
4940 }
4941
4942 void ceph_mdsc_force_umount(struct ceph_mds_client *mdsc)
4943 {
4944         struct ceph_mds_session *session;
4945         int mds;
4946
4947         dout("force umount\n");
4948
4949         mutex_lock(&mdsc->mutex);
4950         for (mds = 0; mds < mdsc->max_sessions; mds++) {
4951                 session = __ceph_lookup_mds_session(mdsc, mds);
4952                 if (!session)
4953                         continue;
4954
4955                 if (session->s_state == CEPH_MDS_SESSION_REJECTED)
4956                         __unregister_session(mdsc, session);
4957                 __wake_requests(mdsc, &session->s_waiting);
4958                 mutex_unlock(&mdsc->mutex);
4959
4960                 mutex_lock(&session->s_mutex);
4961                 __close_session(mdsc, session);
4962                 if (session->s_state == CEPH_MDS_SESSION_CLOSING) {
4963                         cleanup_session_requests(mdsc, session);
4964                         remove_session_caps(session);
4965                 }
4966                 mutex_unlock(&session->s_mutex);
4967                 ceph_put_mds_session(session);
4968
4969                 mutex_lock(&mdsc->mutex);
4970                 kick_requests(mdsc, mds);
4971         }
4972         __wake_requests(mdsc, &mdsc->waiting_for_map);
4973         mutex_unlock(&mdsc->mutex);
4974 }
4975
4976 static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
4977 {
4978         dout("stop\n");
4979         /*
4980          * Make sure the delayed work stopped before releasing
4981          * the resources.
4982          *
4983          * Because the cancel_delayed_work_sync() will only
4984          * guarantee that the work finishes executing. But the
4985          * delayed work will re-arm itself again after that.
4986          */
4987         flush_delayed_work(&mdsc->delayed_work);
4988
4989         if (mdsc->mdsmap)
4990                 ceph_mdsmap_destroy(mdsc->mdsmap);
4991         kfree(mdsc->sessions);
4992         ceph_caps_finalize(mdsc);
4993         ceph_pool_perm_destroy(mdsc);
4994 }
4995
4996 void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
4997 {
4998         struct ceph_mds_client *mdsc = fsc->mdsc;
4999         dout("mdsc_destroy %p\n", mdsc);
5000
5001         if (!mdsc)
5002                 return;
5003
5004         /* flush out any connection work with references to us */
5005         ceph_msgr_flush();
5006
5007         ceph_mdsc_stop(mdsc);
5008
5009         ceph_metric_destroy(&mdsc->metric);
5010
5011         fsc->mdsc = NULL;
5012         kfree(mdsc);
5013         dout("mdsc_destroy %p done\n", mdsc);
5014 }
5015
5016 void ceph_mdsc_handle_fsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
5017 {
5018         struct ceph_fs_client *fsc = mdsc->fsc;
5019         const char *mds_namespace = fsc->mount_options->mds_namespace;
5020         void *p = msg->front.iov_base;
5021         void *end = p + msg->front.iov_len;
5022         u32 epoch;
5023         u32 num_fs;
5024         u32 mount_fscid = (u32)-1;
5025         int err = -EINVAL;
5026
5027         ceph_decode_need(&p, end, sizeof(u32), bad);
5028         epoch = ceph_decode_32(&p);
5029
5030         dout("handle_fsmap epoch %u\n", epoch);
5031
5032         /* struct_v, struct_cv, map_len, epoch, legacy_client_fscid */
5033         ceph_decode_skip_n(&p, end, 2 + sizeof(u32) * 3, bad);
5034
5035         ceph_decode_32_safe(&p, end, num_fs, bad);
5036         while (num_fs-- > 0) {
5037                 void *info_p, *info_end;
5038                 u32 info_len;
5039                 u32 fscid, namelen;
5040
5041                 ceph_decode_need(&p, end, 2 + sizeof(u32), bad);
5042                 p += 2;         // info_v, info_cv
5043                 info_len = ceph_decode_32(&p);
5044                 ceph_decode_need(&p, end, info_len, bad);
5045                 info_p = p;
5046                 info_end = p + info_len;
5047                 p = info_end;
5048
5049                 ceph_decode_need(&info_p, info_end, sizeof(u32) * 2, bad);
5050                 fscid = ceph_decode_32(&info_p);
5051                 namelen = ceph_decode_32(&info_p);
5052                 ceph_decode_need(&info_p, info_end, namelen, bad);
5053
5054                 if (mds_namespace &&
5055                     strlen(mds_namespace) == namelen &&
5056                     !strncmp(mds_namespace, (char *)info_p, namelen)) {
5057                         mount_fscid = fscid;
5058                         break;
5059                 }
5060         }
5061
5062         ceph_monc_got_map(&fsc->client->monc, CEPH_SUB_FSMAP, epoch);
5063         if (mount_fscid != (u32)-1) {
5064                 fsc->client->monc.fs_cluster_id = mount_fscid;
5065                 ceph_monc_want_map(&fsc->client->monc, CEPH_SUB_MDSMAP,
5066                                    0, true);
5067                 ceph_monc_renew_subs(&fsc->client->monc);
5068         } else {
5069                 err = -ENOENT;
5070                 goto err_out;
5071         }
5072         return;
5073
5074 bad:
5075         pr_err("error decoding fsmap\n");
5076 err_out:
5077         mutex_lock(&mdsc->mutex);
5078         mdsc->mdsmap_err = err;
5079         __wake_requests(mdsc, &mdsc->waiting_for_map);
5080         mutex_unlock(&mdsc->mutex);
5081 }
5082
5083 /*
5084  * handle mds map update.
5085  */
5086 void ceph_mdsc_handle_mdsmap(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
5087 {
5088         u32 epoch;
5089         u32 maplen;
5090         void *p = msg->front.iov_base;
5091         void *end = p + msg->front.iov_len;
5092         struct ceph_mdsmap *newmap, *oldmap;
5093         struct ceph_fsid fsid;
5094         int err = -EINVAL;
5095
5096         ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
5097         ceph_decode_copy(&p, &fsid, sizeof(fsid));
5098         if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
5099                 return;
5100         epoch = ceph_decode_32(&p);
5101         maplen = ceph_decode_32(&p);
5102         dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
5103
5104         /* do we need it? */
5105         mutex_lock(&mdsc->mutex);
5106         if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
5107                 dout("handle_map epoch %u <= our %u\n",
5108                      epoch, mdsc->mdsmap->m_epoch);
5109                 mutex_unlock(&mdsc->mutex);
5110                 return;
5111         }
5112
5113         newmap = ceph_mdsmap_decode(&p, end, ceph_msgr2(mdsc->fsc->client));
5114         if (IS_ERR(newmap)) {
5115                 err = PTR_ERR(newmap);
5116                 goto bad_unlock;
5117         }
5118
5119         /* swap into place */
5120         if (mdsc->mdsmap) {
5121                 oldmap = mdsc->mdsmap;
5122                 mdsc->mdsmap = newmap;
5123                 check_new_map(mdsc, newmap, oldmap);
5124                 ceph_mdsmap_destroy(oldmap);
5125         } else {
5126                 mdsc->mdsmap = newmap;  /* first mds map */
5127         }
5128         mdsc->fsc->max_file_size = min((loff_t)mdsc->mdsmap->m_max_file_size,
5129                                         MAX_LFS_FILESIZE);
5130
5131         __wake_requests(mdsc, &mdsc->waiting_for_map);
5132         ceph_monc_got_map(&mdsc->fsc->client->monc, CEPH_SUB_MDSMAP,
5133                           mdsc->mdsmap->m_epoch);
5134
5135         mutex_unlock(&mdsc->mutex);
5136         schedule_delayed(mdsc, 0);
5137         return;
5138
5139 bad_unlock:
5140         mutex_unlock(&mdsc->mutex);
5141 bad:
5142         pr_err("error decoding mdsmap %d\n", err);
5143         return;
5144 }
5145
5146 static struct ceph_connection *mds_get_con(struct ceph_connection *con)
5147 {
5148         struct ceph_mds_session *s = con->private;
5149
5150         if (ceph_get_mds_session(s))
5151                 return con;
5152         return NULL;
5153 }
5154
5155 static void mds_put_con(struct ceph_connection *con)
5156 {
5157         struct ceph_mds_session *s = con->private;
5158
5159         ceph_put_mds_session(s);
5160 }
5161
5162 /*
5163  * if the client is unresponsive for long enough, the mds will kill
5164  * the session entirely.
5165  */
5166 static void mds_peer_reset(struct ceph_connection *con)
5167 {
5168         struct ceph_mds_session *s = con->private;
5169         struct ceph_mds_client *mdsc = s->s_mdsc;
5170
5171         pr_warn("mds%d closed our session\n", s->s_mds);
5172         send_mds_reconnect(mdsc, s);
5173 }
5174
5175 static void mds_dispatch(struct ceph_connection *con, struct ceph_msg *msg)
5176 {
5177         struct ceph_mds_session *s = con->private;
5178         struct ceph_mds_client *mdsc = s->s_mdsc;
5179         int type = le16_to_cpu(msg->hdr.type);
5180
5181         mutex_lock(&mdsc->mutex);
5182         if (__verify_registered_session(mdsc, s) < 0) {
5183                 mutex_unlock(&mdsc->mutex);
5184                 goto out;
5185         }
5186         mutex_unlock(&mdsc->mutex);
5187
5188         switch (type) {
5189         case CEPH_MSG_MDS_MAP:
5190                 ceph_mdsc_handle_mdsmap(mdsc, msg);
5191                 break;
5192         case CEPH_MSG_FS_MAP_USER:
5193                 ceph_mdsc_handle_fsmap(mdsc, msg);
5194                 break;
5195         case CEPH_MSG_CLIENT_SESSION:
5196                 handle_session(s, msg);
5197                 break;
5198         case CEPH_MSG_CLIENT_REPLY:
5199                 handle_reply(s, msg);
5200                 break;
5201         case CEPH_MSG_CLIENT_REQUEST_FORWARD:
5202                 handle_forward(mdsc, s, msg);
5203                 break;
5204         case CEPH_MSG_CLIENT_CAPS:
5205                 ceph_handle_caps(s, msg);
5206                 break;
5207         case CEPH_MSG_CLIENT_SNAP:
5208                 ceph_handle_snap(mdsc, s, msg);
5209                 break;
5210         case CEPH_MSG_CLIENT_LEASE:
5211                 handle_lease(mdsc, s, msg);
5212                 break;
5213         case CEPH_MSG_CLIENT_QUOTA:
5214                 ceph_handle_quota(mdsc, s, msg);
5215                 break;
5216
5217         default:
5218                 pr_err("received unknown message type %d %s\n", type,
5219                        ceph_msg_type_name(type));
5220         }
5221 out:
5222         ceph_msg_put(msg);
5223 }
5224
5225 /*
5226  * authentication
5227  */
5228
5229 /*
5230  * Note: returned pointer is the address of a structure that's
5231  * managed separately.  Caller must *not* attempt to free it.
5232  */
5233 static struct ceph_auth_handshake *
5234 mds_get_authorizer(struct ceph_connection *con, int *proto, int force_new)
5235 {
5236         struct ceph_mds_session *s = con->private;
5237         struct ceph_mds_client *mdsc = s->s_mdsc;
5238         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5239         struct ceph_auth_handshake *auth = &s->s_auth;
5240         int ret;
5241
5242         ret = __ceph_auth_get_authorizer(ac, auth, CEPH_ENTITY_TYPE_MDS,
5243                                          force_new, proto, NULL, NULL);
5244         if (ret)
5245                 return ERR_PTR(ret);
5246
5247         return auth;
5248 }
5249
5250 static int mds_add_authorizer_challenge(struct ceph_connection *con,
5251                                     void *challenge_buf, int challenge_buf_len)
5252 {
5253         struct ceph_mds_session *s = con->private;
5254         struct ceph_mds_client *mdsc = s->s_mdsc;
5255         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5256
5257         return ceph_auth_add_authorizer_challenge(ac, s->s_auth.authorizer,
5258                                             challenge_buf, challenge_buf_len);
5259 }
5260
5261 static int mds_verify_authorizer_reply(struct ceph_connection *con)
5262 {
5263         struct ceph_mds_session *s = con->private;
5264         struct ceph_mds_client *mdsc = s->s_mdsc;
5265         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5266         struct ceph_auth_handshake *auth = &s->s_auth;
5267
5268         return ceph_auth_verify_authorizer_reply(ac, auth->authorizer,
5269                 auth->authorizer_reply_buf, auth->authorizer_reply_buf_len,
5270                 NULL, NULL, NULL, NULL);
5271 }
5272
5273 static int mds_invalidate_authorizer(struct ceph_connection *con)
5274 {
5275         struct ceph_mds_session *s = con->private;
5276         struct ceph_mds_client *mdsc = s->s_mdsc;
5277         struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
5278
5279         ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
5280
5281         return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
5282 }
5283
5284 static int mds_get_auth_request(struct ceph_connection *con,
5285                                 void *buf, int *buf_len,
5286                                 void **authorizer, int *authorizer_len)
5287 {
5288         struct ceph_mds_session *s = con->private;
5289         struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5290         struct ceph_auth_handshake *auth = &s->s_auth;
5291         int ret;
5292
5293         ret = ceph_auth_get_authorizer(ac, auth, CEPH_ENTITY_TYPE_MDS,
5294                                        buf, buf_len);
5295         if (ret)
5296                 return ret;
5297
5298         *authorizer = auth->authorizer_buf;
5299         *authorizer_len = auth->authorizer_buf_len;
5300         return 0;
5301 }
5302
5303 static int mds_handle_auth_reply_more(struct ceph_connection *con,
5304                                       void *reply, int reply_len,
5305                                       void *buf, int *buf_len,
5306                                       void **authorizer, int *authorizer_len)
5307 {
5308         struct ceph_mds_session *s = con->private;
5309         struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5310         struct ceph_auth_handshake *auth = &s->s_auth;
5311         int ret;
5312
5313         ret = ceph_auth_handle_svc_reply_more(ac, auth, reply, reply_len,
5314                                               buf, buf_len);
5315         if (ret)
5316                 return ret;
5317
5318         *authorizer = auth->authorizer_buf;
5319         *authorizer_len = auth->authorizer_buf_len;
5320         return 0;
5321 }
5322
5323 static int mds_handle_auth_done(struct ceph_connection *con,
5324                                 u64 global_id, void *reply, int reply_len,
5325                                 u8 *session_key, int *session_key_len,
5326                                 u8 *con_secret, int *con_secret_len)
5327 {
5328         struct ceph_mds_session *s = con->private;
5329         struct ceph_auth_client *ac = s->s_mdsc->fsc->client->monc.auth;
5330         struct ceph_auth_handshake *auth = &s->s_auth;
5331
5332         return ceph_auth_handle_svc_reply_done(ac, auth, reply, reply_len,
5333                                                session_key, session_key_len,
5334                                                con_secret, con_secret_len);
5335 }
5336
5337 static int mds_handle_auth_bad_method(struct ceph_connection *con,
5338                                       int used_proto, int result,
5339                                       const int *allowed_protos, int proto_cnt,
5340                                       const int *allowed_modes, int mode_cnt)
5341 {
5342         struct ceph_mds_session *s = con->private;
5343         struct ceph_mon_client *monc = &s->s_mdsc->fsc->client->monc;
5344         int ret;
5345
5346         if (ceph_auth_handle_bad_authorizer(monc->auth, CEPH_ENTITY_TYPE_MDS,
5347                                             used_proto, result,
5348                                             allowed_protos, proto_cnt,
5349                                             allowed_modes, mode_cnt)) {
5350                 ret = ceph_monc_validate_auth(monc);
5351                 if (ret)
5352                         return ret;
5353         }
5354
5355         return -EACCES;
5356 }
5357
5358 static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
5359                                 struct ceph_msg_header *hdr, int *skip)
5360 {
5361         struct ceph_msg *msg;
5362         int type = (int) le16_to_cpu(hdr->type);
5363         int front_len = (int) le32_to_cpu(hdr->front_len);
5364
5365         if (con->in_msg)
5366                 return con->in_msg;
5367
5368         *skip = 0;
5369         msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
5370         if (!msg) {
5371                 pr_err("unable to allocate msg type %d len %d\n",
5372                        type, front_len);
5373                 return NULL;
5374         }
5375
5376         return msg;
5377 }
5378
5379 static int mds_sign_message(struct ceph_msg *msg)
5380 {
5381        struct ceph_mds_session *s = msg->con->private;
5382        struct ceph_auth_handshake *auth = &s->s_auth;
5383
5384        return ceph_auth_sign_message(auth, msg);
5385 }
5386
5387 static int mds_check_message_signature(struct ceph_msg *msg)
5388 {
5389        struct ceph_mds_session *s = msg->con->private;
5390        struct ceph_auth_handshake *auth = &s->s_auth;
5391
5392        return ceph_auth_check_message_signature(auth, msg);
5393 }
5394
5395 static const struct ceph_connection_operations mds_con_ops = {
5396         .get = mds_get_con,
5397         .put = mds_put_con,
5398         .alloc_msg = mds_alloc_msg,
5399         .dispatch = mds_dispatch,
5400         .peer_reset = mds_peer_reset,
5401         .get_authorizer = mds_get_authorizer,
5402         .add_authorizer_challenge = mds_add_authorizer_challenge,
5403         .verify_authorizer_reply = mds_verify_authorizer_reply,
5404         .invalidate_authorizer = mds_invalidate_authorizer,
5405         .sign_message = mds_sign_message,
5406         .check_message_signature = mds_check_message_signature,
5407         .get_auth_request = mds_get_auth_request,
5408         .handle_auth_reply_more = mds_handle_auth_reply_more,
5409         .handle_auth_done = mds_handle_auth_done,
5410         .handle_auth_bad_method = mds_handle_auth_bad_method,
5411 };
5412
5413 /* eof */