linux/fs/ceph/mds_client.c
<<
>>
Prefs
   1#include <linux/ceph/ceph_debug.h>
   2
   3#include <linux/fs.h>
   4#include <linux/wait.h>
   5#include <linux/slab.h>
   6#include <linux/sched.h>
   7#include <linux/debugfs.h>
   8#include <linux/seq_file.h>
   9
  10#include "super.h"
  11#include "mds_client.h"
  12
  13#include <linux/ceph/ceph_features.h>
  14#include <linux/ceph/messenger.h>
  15#include <linux/ceph/decode.h>
  16#include <linux/ceph/pagelist.h>
  17#include <linux/ceph/auth.h>
  18#include <linux/ceph/debugfs.h>
  19
  20/*
  21 * A cluster of MDS (metadata server) daemons is responsible for
  22 * managing the file system namespace (the directory hierarchy and
  23 * inodes) and for coordinating shared access to storage.  Metadata is
  24 * partitioning hierarchically across a number of servers, and that
  25 * partition varies over time as the cluster adjusts the distribution
  26 * in order to balance load.
  27 *
  28 * The MDS client is primarily responsible to managing synchronous
  29 * metadata requests for operations like open, unlink, and so forth.
  30 * If there is a MDS failure, we find out about it when we (possibly
  31 * request and) receive a new MDS map, and can resubmit affected
  32 * requests.
  33 *
  34 * For the most part, though, we take advantage of a lossless
  35 * communications channel to the MDS, and do not need to worry about
  36 * timing out or resubmitting requests.
  37 *
  38 * We maintain a stateful "session" with each MDS we interact with.
  39 * Within each session, we sent periodic heartbeat messages to ensure
  40 * any capabilities or leases we have been issues remain valid.  If
  41 * the session times out and goes stale, our leases and capabilities
  42 * are no longer valid.
  43 */
  44
  45struct ceph_reconnect_state {
  46        int nr_caps;
  47        struct ceph_pagelist *pagelist;
  48        bool flock;
  49};
  50
  51static void __wake_requests(struct ceph_mds_client *mdsc,
  52                            struct list_head *head);
  53
  54static const struct ceph_connection_operations mds_con_ops;
  55
  56
  57/*
  58 * mds reply parsing
  59 */
  60
  61/*
  62 * parse individual inode info
  63 */
  64static int parse_reply_info_in(void **p, void *end,
  65                               struct ceph_mds_reply_info_in *info,
  66                               int features)
  67{
  68        int err = -EIO;
  69
  70        info->in = *p;
  71        *p += sizeof(struct ceph_mds_reply_inode) +
  72                sizeof(*info->in->fragtree.splits) *
  73                le32_to_cpu(info->in->fragtree.nsplits);
  74
  75        ceph_decode_32_safe(p, end, info->symlink_len, bad);
  76        ceph_decode_need(p, end, info->symlink_len, bad);
  77        info->symlink = *p;
  78        *p += info->symlink_len;
  79
  80        if (features & CEPH_FEATURE_DIRLAYOUTHASH)
  81                ceph_decode_copy_safe(p, end, &info->dir_layout,
  82                                      sizeof(info->dir_layout), bad);
  83        else
  84                memset(&info->dir_layout, 0, sizeof(info->dir_layout));
  85
  86        ceph_decode_32_safe(p, end, info->xattr_len, bad);
  87        ceph_decode_need(p, end, info->xattr_len, bad);
  88        info->xattr_data = *p;
  89        *p += info->xattr_len;
  90        return 0;
  91bad:
  92        return err;
  93}
  94
  95/*
  96 * parse a normal reply, which may contain a (dir+)dentry and/or a
  97 * target inode.
  98 */
  99static int parse_reply_info_trace(void **p, void *end,
 100                                  struct ceph_mds_reply_info_parsed *info,
 101                                  int features)
 102{
 103        int err;
 104
 105        if (info->head->is_dentry) {
 106                err = parse_reply_info_in(p, end, &info->diri, features);
 107                if (err < 0)
 108                        goto out_bad;
 109
 110                if (unlikely(*p + sizeof(*info->dirfrag) > end))
 111                        goto bad;
 112                info->dirfrag = *p;
 113                *p += sizeof(*info->dirfrag) +
 114                        sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 115                if (unlikely(*p > end))
 116                        goto bad;
 117
 118                ceph_decode_32_safe(p, end, info->dname_len, bad);
 119                ceph_decode_need(p, end, info->dname_len, bad);
 120                info->dname = *p;
 121                *p += info->dname_len;
 122                info->dlease = *p;
 123                *p += sizeof(*info->dlease);
 124        }
 125
 126        if (info->head->is_target) {
 127                err = parse_reply_info_in(p, end, &info->targeti, features);
 128                if (err < 0)
 129                        goto out_bad;
 130        }
 131
 132        if (unlikely(*p != end))
 133                goto bad;
 134        return 0;
 135
 136bad:
 137        err = -EIO;
 138out_bad:
 139        pr_err("problem parsing mds trace %d\n", err);
 140        return err;
 141}
 142
 143/*
 144 * parse readdir results
 145 */
 146static int parse_reply_info_dir(void **p, void *end,
 147                                struct ceph_mds_reply_info_parsed *info,
 148                                int features)
 149{
 150        u32 num, i = 0;
 151        int err;
 152
 153        info->dir_dir = *p;
 154        if (*p + sizeof(*info->dir_dir) > end)
 155                goto bad;
 156        *p += sizeof(*info->dir_dir) +
 157                sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 158        if (*p > end)
 159                goto bad;
 160
 161        ceph_decode_need(p, end, sizeof(num) + 2, bad);
 162        num = ceph_decode_32(p);
 163        info->dir_end = ceph_decode_8(p);
 164        info->dir_complete = ceph_decode_8(p);
 165        if (num == 0)
 166                goto done;
 167
 168        /* alloc large array */
 169        info->dir_nr = num;
 170        info->dir_in = kcalloc(num, sizeof(*info->dir_in) +
 171                               sizeof(*info->dir_dname) +
 172                               sizeof(*info->dir_dname_len) +
 173                               sizeof(*info->dir_dlease),
 174                               GFP_NOFS);
 175        if (info->dir_in == NULL) {
 176                err = -ENOMEM;
 177                goto out_bad;
 178        }
 179        info->dir_dname = (void *)(info->dir_in + num);
 180        info->dir_dname_len = (void *)(info->dir_dname + num);
 181        info->dir_dlease = (void *)(info->dir_dname_len + num);
 182
 183        while (num) {
 184                /* dentry */
 185                ceph_decode_need(p, end, sizeof(u32)*2, bad);
 186                info->dir_dname_len[i] = ceph_decode_32(p);
 187                ceph_decode_need(p, end, info->dir_dname_len[i], bad);
 188                info->dir_dname[i] = *p;
 189                *p += info->dir_dname_len[i];
 190                dout("parsed dir dname '%.*s'\n", info->dir_dname_len[i],
 191                     info->dir_dname[i]);
 192                info->dir_dlease[i] = *p;
 193                *p += sizeof(struct ceph_mds_reply_lease);
 194
 195                /* inode */
 196                err = parse_reply_info_in(p, end, &info->dir_in[i], features);
 197                if (err < 0)
 198                        goto out_bad;
 199                i++;
 200                num--;
 201        }
 202
 203done:
 204        if (*p != end)
 205                goto bad;
 206        return 0;
 207
 208bad:
 209        err = -EIO;
 210out_bad:
 211        pr_err("problem parsing dir contents %d\n", err);
 212        return err;
 213}
 214
 215/*
 216 * parse fcntl F_GETLK results
 217 */
 218static int parse_reply_info_filelock(void **p, void *end,
 219                                     struct ceph_mds_reply_info_parsed *info,
 220                                     int features)
 221{
 222        if (*p + sizeof(*info->filelock_reply) > end)
 223                goto bad;
 224
 225        info->filelock_reply = *p;
 226        *p += sizeof(*info->filelock_reply);
 227
 228        if (unlikely(*p != end))
 229                goto bad;
 230        return 0;
 231
 232bad:
 233        return -EIO;
 234}
 235
 236/*
 237 * parse create results
 238 */
 239static int parse_reply_info_create(void **p, void *end,
 240                                  struct ceph_mds_reply_info_parsed *info,
 241                                  int features)
 242{
 243        if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 244                if (*p == end) {
 245                        info->has_create_ino = false;
 246                } else {
 247                        info->has_create_ino = true;
 248                        info->ino = ceph_decode_64(p);
 249                }
 250        }
 251
 252        if (unlikely(*p != end))
 253                goto bad;
 254        return 0;
 255
 256bad:
 257        return -EIO;
 258}
 259
 260/*
 261 * parse extra results
 262 */
 263static int parse_reply_info_extra(void **p, void *end,
 264                                  struct ceph_mds_reply_info_parsed *info,
 265                                  int features)
 266{
 267        if (info->head->op == CEPH_MDS_OP_GETFILELOCK)
 268                return parse_reply_info_filelock(p, end, info, features);
 269        else if (info->head->op == CEPH_MDS_OP_READDIR ||
 270                 info->head->op == CEPH_MDS_OP_LSSNAP)
 271                return parse_reply_info_dir(p, end, info, features);
 272        else if (info->head->op == CEPH_MDS_OP_CREATE)
 273                return parse_reply_info_create(p, end, info, features);
 274        else
 275                return -EIO;
 276}
 277
 278/*
 279 * parse entire mds reply
 280 */
 281static int parse_reply_info(struct ceph_msg *msg,
 282                            struct ceph_mds_reply_info_parsed *info,
 283                            int features)
 284{
 285        void *p, *end;
 286        u32 len;
 287        int err;
 288
 289        info->head = msg->front.iov_base;
 290        p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 291        end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 292
 293        /* trace */
 294        ceph_decode_32_safe(&p, end, len, bad);
 295        if (len > 0) {
 296                ceph_decode_need(&p, end, len, bad);
 297                err = parse_reply_info_trace(&p, p+len, info, features);
 298                if (err < 0)
 299                        goto out_bad;
 300        }
 301
 302        /* extra */
 303        ceph_decode_32_safe(&p, end, len, bad);
 304        if (len > 0) {
 305                ceph_decode_need(&p, end, len, bad);
 306                err = parse_reply_info_extra(&p, p+len, info, features);
 307                if (err < 0)
 308                        goto out_bad;
 309        }
 310
 311        /* snap blob */
 312        ceph_decode_32_safe(&p, end, len, bad);
 313        info->snapblob_len = len;
 314        info->snapblob = p;
 315        p += len;
 316
 317        if (p != end)
 318                goto bad;
 319        return 0;
 320
 321bad:
 322        err = -EIO;
 323out_bad:
 324        pr_err("mds parse_reply err %d\n", err);
 325        return err;
 326}
 327
 328static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 329{
 330        kfree(info->dir_in);
 331}
 332
 333
 334/*
 335 * sessions
 336 */
 337static const char *session_state_name(int s)
 338{
 339        switch (s) {
 340        case CEPH_MDS_SESSION_NEW: return "new";
 341        case CEPH_MDS_SESSION_OPENING: return "opening";
 342        case CEPH_MDS_SESSION_OPEN: return "open";
 343        case CEPH_MDS_SESSION_HUNG: return "hung";
 344        case CEPH_MDS_SESSION_CLOSING: return "closing";
 345        case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 346        case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 347        default: return "???";
 348        }
 349}
 350
 351static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 352{
 353        if (atomic_inc_not_zero(&s->s_ref)) {
 354                dout("mdsc get_session %p %d -> %d\n", s,
 355                     atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
 356                return s;
 357        } else {
 358                dout("mdsc get_session %p 0 -- FAIL", s);
 359                return NULL;
 360        }
 361}
 362
 363void ceph_put_mds_session(struct ceph_mds_session *s)
 364{
 365        dout("mdsc put_session %p %d -> %d\n", s,
 366             atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
 367        if (atomic_dec_and_test(&s->s_ref)) {
 368                if (s->s_auth.authorizer)
 369                        ceph_auth_destroy_authorizer(
 370                                s->s_mdsc->fsc->client->monc.auth,
 371                                s->s_auth.authorizer);
 372                kfree(s);
 373        }
 374}
 375
 376/*
 377 * called under mdsc->mutex
 378 */
 379struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 380                                                   int mds)
 381{
 382        struct ceph_mds_session *session;
 383
 384        if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
 385                return NULL;
 386        session = mdsc->sessions[mds];
 387        dout("lookup_mds_session %p %d\n", session,
 388             atomic_read(&session->s_ref));
 389        get_session(session);
 390        return session;
 391}
 392
 393static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 394{
 395        if (mds >= mdsc->max_sessions)
 396                return false;
 397        return mdsc->sessions[mds];
 398}
 399
 400static int __verify_registered_session(struct ceph_mds_client *mdsc,
 401                                       struct ceph_mds_session *s)
 402{
 403        if (s->s_mds >= mdsc->max_sessions ||
 404            mdsc->sessions[s->s_mds] != s)
 405                return -ENOENT;
 406        return 0;
 407}
 408
 409/*
 410 * create+register a new session for given mds.
 411 * called under mdsc->mutex.
 412 */
 413static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 414                                                 int mds)
 415{
 416        struct ceph_mds_session *s;
 417
 418        if (mds >= mdsc->mdsmap->m_max_mds)
 419                return ERR_PTR(-EINVAL);
 420
 421        s = kzalloc(sizeof(*s), GFP_NOFS);
 422        if (!s)
 423                return ERR_PTR(-ENOMEM);
 424        s->s_mdsc = mdsc;
 425        s->s_mds = mds;
 426        s->s_state = CEPH_MDS_SESSION_NEW;
 427        s->s_ttl = 0;
 428        s->s_seq = 0;
 429        mutex_init(&s->s_mutex);
 430
 431        ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 432
 433        spin_lock_init(&s->s_gen_ttl_lock);
 434        s->s_cap_gen = 0;
 435        s->s_cap_ttl = jiffies - 1;
 436
 437        spin_lock_init(&s->s_cap_lock);
 438        s->s_renew_requested = 0;
 439        s->s_renew_seq = 0;
 440        INIT_LIST_HEAD(&s->s_caps);
 441        s->s_nr_caps = 0;
 442        s->s_trim_caps = 0;
 443        atomic_set(&s->s_ref, 1);
 444        INIT_LIST_HEAD(&s->s_waiting);
 445        INIT_LIST_HEAD(&s->s_unsafe);
 446        s->s_num_cap_releases = 0;
 447        s->s_cap_reconnect = 0;
 448        s->s_cap_iterator = NULL;
 449        INIT_LIST_HEAD(&s->s_cap_releases);
 450        INIT_LIST_HEAD(&s->s_cap_releases_done);
 451        INIT_LIST_HEAD(&s->s_cap_flushing);
 452        INIT_LIST_HEAD(&s->s_cap_snaps_flushing);
 453
 454        dout("register_session mds%d\n", mds);
 455        if (mds >= mdsc->max_sessions) {
 456                int newmax = 1 << get_count_order(mds+1);
 457                struct ceph_mds_session **sa;
 458
 459                dout("register_session realloc to %d\n", newmax);
 460                sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 461                if (sa == NULL)
 462                        goto fail_realloc;
 463                if (mdsc->sessions) {
 464                        memcpy(sa, mdsc->sessions,
 465                               mdsc->max_sessions * sizeof(void *));
 466                        kfree(mdsc->sessions);
 467                }
 468                mdsc->sessions = sa;
 469                mdsc->max_sessions = newmax;
 470        }
 471        mdsc->sessions[mds] = s;
 472        atomic_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 473
 474        ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 475                      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 476
 477        return s;
 478
 479fail_realloc:
 480        kfree(s);
 481        return ERR_PTR(-ENOMEM);
 482}
 483
 484/*
 485 * called under mdsc->mutex
 486 */
 487static void __unregister_session(struct ceph_mds_client *mdsc,
 488                               struct ceph_mds_session *s)
 489{
 490        dout("__unregister_session mds%d %p\n", s->s_mds, s);
 491        BUG_ON(mdsc->sessions[s->s_mds] != s);
 492        mdsc->sessions[s->s_mds] = NULL;
 493        ceph_con_close(&s->s_con);
 494        ceph_put_mds_session(s);
 495}
 496
 497/*
 498 * drop session refs in request.
 499 *
 500 * should be last request ref, or hold mdsc->mutex
 501 */
 502static void put_request_session(struct ceph_mds_request *req)
 503{
 504        if (req->r_session) {
 505                ceph_put_mds_session(req->r_session);
 506                req->r_session = NULL;
 507        }
 508}
 509
 510void ceph_mdsc_release_request(struct kref *kref)
 511{
 512        struct ceph_mds_request *req = container_of(kref,
 513                                                    struct ceph_mds_request,
 514                                                    r_kref);
 515        if (req->r_request)
 516                ceph_msg_put(req->r_request);
 517        if (req->r_reply) {
 518                ceph_msg_put(req->r_reply);
 519                destroy_reply_info(&req->r_reply_info);
 520        }
 521        if (req->r_inode) {
 522                ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 523                iput(req->r_inode);
 524        }
 525        if (req->r_locked_dir)
 526                ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
 527        if (req->r_target_inode)
 528                iput(req->r_target_inode);
 529        if (req->r_dentry)
 530                dput(req->r_dentry);
 531        if (req->r_old_dentry) {
 532                /*
 533                 * track (and drop pins for) r_old_dentry_dir
 534                 * separately, since r_old_dentry's d_parent may have
 535                 * changed between the dir mutex being dropped and
 536                 * this request being freed.
 537                 */
 538                ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 539                                  CEPH_CAP_PIN);
 540                dput(req->r_old_dentry);
 541                iput(req->r_old_dentry_dir);
 542        }
 543        kfree(req->r_path1);
 544        kfree(req->r_path2);
 545        put_request_session(req);
 546        ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 547        kfree(req);
 548}
 549
 550/*
 551 * lookup session, bump ref if found.
 552 *
 553 * called under mdsc->mutex.
 554 */
 555static struct ceph_mds_request *__lookup_request(struct ceph_mds_client *mdsc,
 556                                             u64 tid)
 557{
 558        struct ceph_mds_request *req;
 559        struct rb_node *n = mdsc->request_tree.rb_node;
 560
 561        while (n) {
 562                req = rb_entry(n, struct ceph_mds_request, r_node);
 563                if (tid < req->r_tid)
 564                        n = n->rb_left;
 565                else if (tid > req->r_tid)
 566                        n = n->rb_right;
 567                else {
 568                        ceph_mdsc_get_request(req);
 569                        return req;
 570                }
 571        }
 572        return NULL;
 573}
 574
 575static void __insert_request(struct ceph_mds_client *mdsc,
 576                             struct ceph_mds_request *new)
 577{
 578        struct rb_node **p = &mdsc->request_tree.rb_node;
 579        struct rb_node *parent = NULL;
 580        struct ceph_mds_request *req = NULL;
 581
 582        while (*p) {
 583                parent = *p;
 584                req = rb_entry(parent, struct ceph_mds_request, r_node);
 585                if (new->r_tid < req->r_tid)
 586                        p = &(*p)->rb_left;
 587                else if (new->r_tid > req->r_tid)
 588                        p = &(*p)->rb_right;
 589                else
 590                        BUG();
 591        }
 592
 593        rb_link_node(&new->r_node, parent, p);
 594        rb_insert_color(&new->r_node, &mdsc->request_tree);
 595}
 596
 597/*
 598 * Register an in-flight request, and assign a tid.  Link to directory
 599 * are modifying (if any).
 600 *
 601 * Called under mdsc->mutex.
 602 */
 603static void __register_request(struct ceph_mds_client *mdsc,
 604                               struct ceph_mds_request *req,
 605                               struct inode *dir)
 606{
 607        req->r_tid = ++mdsc->last_tid;
 608        if (req->r_num_caps)
 609                ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 610                                  req->r_num_caps);
 611        dout("__register_request %p tid %lld\n", req, req->r_tid);
 612        ceph_mdsc_get_request(req);
 613        __insert_request(mdsc, req);
 614
 615        req->r_uid = current_fsuid();
 616        req->r_gid = current_fsgid();
 617
 618        if (dir) {
 619                struct ceph_inode_info *ci = ceph_inode(dir);
 620
 621                ihold(dir);
 622                spin_lock(&ci->i_unsafe_lock);
 623                req->r_unsafe_dir = dir;
 624                list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 625                spin_unlock(&ci->i_unsafe_lock);
 626        }
 627}
 628
 629static void __unregister_request(struct ceph_mds_client *mdsc,
 630                                 struct ceph_mds_request *req)
 631{
 632        dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 633        rb_erase(&req->r_node, &mdsc->request_tree);
 634        RB_CLEAR_NODE(&req->r_node);
 635
 636        if (req->r_unsafe_dir) {
 637                struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 638
 639                spin_lock(&ci->i_unsafe_lock);
 640                list_del_init(&req->r_unsafe_dir_item);
 641                spin_unlock(&ci->i_unsafe_lock);
 642
 643                iput(req->r_unsafe_dir);
 644                req->r_unsafe_dir = NULL;
 645        }
 646
 647        complete_all(&req->r_safe_completion);
 648
 649        ceph_mdsc_put_request(req);
 650}
 651
 652/*
 653 * Choose mds to send request to next.  If there is a hint set in the
 654 * request (e.g., due to a prior forward hint from the mds), use that.
 655 * Otherwise, consult frag tree and/or caps to identify the
 656 * appropriate mds.  If all else fails, choose randomly.
 657 *
 658 * Called under mdsc->mutex.
 659 */
 660static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 661{
 662        /*
 663         * we don't need to worry about protecting the d_parent access
 664         * here because we never renaming inside the snapped namespace
 665         * except to resplice to another snapdir, and either the old or new
 666         * result is a valid result.
 667         */
 668        while (!IS_ROOT(dentry) && ceph_snap(dentry->d_inode) != CEPH_NOSNAP)
 669                dentry = dentry->d_parent;
 670        return dentry;
 671}
 672
 673static int __choose_mds(struct ceph_mds_client *mdsc,
 674                        struct ceph_mds_request *req)
 675{
 676        struct inode *inode;
 677        struct ceph_inode_info *ci;
 678        struct ceph_cap *cap;
 679        int mode = req->r_direct_mode;
 680        int mds = -1;
 681        u32 hash = req->r_direct_hash;
 682        bool is_hash = req->r_direct_is_hash;
 683
 684        /*
 685         * is there a specific mds we should try?  ignore hint if we have
 686         * no session and the mds is not up (active or recovering).
 687         */
 688        if (req->r_resend_mds >= 0 &&
 689            (__have_session(mdsc, req->r_resend_mds) ||
 690             ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 691                dout("choose_mds using resend_mds mds%d\n",
 692                     req->r_resend_mds);
 693                return req->r_resend_mds;
 694        }
 695
 696        if (mode == USE_RANDOM_MDS)
 697                goto random;
 698
 699        inode = NULL;
 700        if (req->r_inode) {
 701                inode = req->r_inode;
 702        } else if (req->r_dentry) {
 703                /* ignore race with rename; old or new d_parent is okay */
 704                struct dentry *parent = req->r_dentry->d_parent;
 705                struct inode *dir = parent->d_inode;
 706
 707                if (dir->i_sb != mdsc->fsc->sb) {
 708                        /* not this fs! */
 709                        inode = req->r_dentry->d_inode;
 710                } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 711                        /* direct snapped/virtual snapdir requests
 712                         * based on parent dir inode */
 713                        struct dentry *dn = get_nonsnap_parent(parent);
 714                        inode = dn->d_inode;
 715                        dout("__choose_mds using nonsnap parent %p\n", inode);
 716                } else if (req->r_dentry->d_inode) {
 717                        /* dentry target */
 718                        inode = req->r_dentry->d_inode;
 719                } else {
 720                        /* dir + name */
 721                        inode = dir;
 722                        hash = ceph_dentry_hash(dir, req->r_dentry);
 723                        is_hash = true;
 724                }
 725        }
 726
 727        dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 728             (int)hash, mode);
 729        if (!inode)
 730                goto random;
 731        ci = ceph_inode(inode);
 732
 733        if (is_hash && S_ISDIR(inode->i_mode)) {
 734                struct ceph_inode_frag frag;
 735                int found;
 736
 737                ceph_choose_frag(ci, hash, &frag, &found);
 738                if (found) {
 739                        if (mode == USE_ANY_MDS && frag.ndist > 0) {
 740                                u8 r;
 741
 742                                /* choose a random replica */
 743                                get_random_bytes(&r, 1);
 744                                r %= frag.ndist;
 745                                mds = frag.dist[r];
 746                                dout("choose_mds %p %llx.%llx "
 747                                     "frag %u mds%d (%d/%d)\n",
 748                                     inode, ceph_vinop(inode),
 749                                     frag.frag, mds,
 750                                     (int)r, frag.ndist);
 751                                if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 752                                    CEPH_MDS_STATE_ACTIVE)
 753                                        return mds;
 754                        }
 755
 756                        /* since this file/dir wasn't known to be
 757                         * replicated, then we want to look for the
 758                         * authoritative mds. */
 759                        mode = USE_AUTH_MDS;
 760                        if (frag.mds >= 0) {
 761                                /* choose auth mds */
 762                                mds = frag.mds;
 763                                dout("choose_mds %p %llx.%llx "
 764                                     "frag %u mds%d (auth)\n",
 765                                     inode, ceph_vinop(inode), frag.frag, mds);
 766                                if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 767                                    CEPH_MDS_STATE_ACTIVE)
 768                                        return mds;
 769                        }
 770                }
 771        }
 772
 773        spin_lock(&ci->i_ceph_lock);
 774        cap = NULL;
 775        if (mode == USE_AUTH_MDS)
 776                cap = ci->i_auth_cap;
 777        if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 778                cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 779        if (!cap) {
 780                spin_unlock(&ci->i_ceph_lock);
 781                goto random;
 782        }
 783        mds = cap->session->s_mds;
 784        dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 785             inode, ceph_vinop(inode), mds,
 786             cap == ci->i_auth_cap ? "auth " : "", cap);
 787        spin_unlock(&ci->i_ceph_lock);
 788        return mds;
 789
 790random:
 791        mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 792        dout("choose_mds chose random mds%d\n", mds);
 793        return mds;
 794}
 795
 796
 797/*
 798 * session messages
 799 */
 800static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 801{
 802        struct ceph_msg *msg;
 803        struct ceph_mds_session_head *h;
 804
 805        msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 806                           false);
 807        if (!msg) {
 808                pr_err("create_session_msg ENOMEM creating msg\n");
 809                return NULL;
 810        }
 811        h = msg->front.iov_base;
 812        h->op = cpu_to_le32(op);
 813        h->seq = cpu_to_le64(seq);
 814        return msg;
 815}
 816
 817/*
 818 * send session open request.
 819 *
 820 * called under mdsc->mutex
 821 */
 822static int __open_session(struct ceph_mds_client *mdsc,
 823                          struct ceph_mds_session *session)
 824{
 825        struct ceph_msg *msg;
 826        int mstate;
 827        int mds = session->s_mds;
 828
 829        /* wait for mds to go active? */
 830        mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 831        dout("open_session to mds%d (%s)\n", mds,
 832             ceph_mds_state_name(mstate));
 833        session->s_state = CEPH_MDS_SESSION_OPENING;
 834        session->s_renew_requested = jiffies;
 835
 836        /* send connect message */
 837        msg = create_session_msg(CEPH_SESSION_REQUEST_OPEN, session->s_seq);
 838        if (!msg)
 839                return -ENOMEM;
 840        ceph_con_send(&session->s_con, msg);
 841        return 0;
 842}
 843
 844/*
 845 * open sessions for any export targets for the given mds
 846 *
 847 * called under mdsc->mutex
 848 */
 849static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 850                                          struct ceph_mds_session *session)
 851{
 852        struct ceph_mds_info *mi;
 853        struct ceph_mds_session *ts;
 854        int i, mds = session->s_mds;
 855        int target;
 856
 857        if (mds >= mdsc->mdsmap->m_max_mds)
 858                return;
 859        mi = &mdsc->mdsmap->m_info[mds];
 860        dout("open_export_target_sessions for mds%d (%d targets)\n",
 861             session->s_mds, mi->num_export_targets);
 862
 863        for (i = 0; i < mi->num_export_targets; i++) {
 864                target = mi->export_targets[i];
 865                ts = __ceph_lookup_mds_session(mdsc, target);
 866                if (!ts) {
 867                        ts = register_session(mdsc, target);
 868                        if (IS_ERR(ts))
 869                                return;
 870                }
 871                if (session->s_state == CEPH_MDS_SESSION_NEW ||
 872                    session->s_state == CEPH_MDS_SESSION_CLOSING)
 873                        __open_session(mdsc, session);
 874                else
 875                        dout(" mds%d target mds%d %p is %s\n", session->s_mds,
 876                             i, ts, session_state_name(ts->s_state));
 877                ceph_put_mds_session(ts);
 878        }
 879}
 880
 881void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 882                                           struct ceph_mds_session *session)
 883{
 884        mutex_lock(&mdsc->mutex);
 885        __open_export_target_sessions(mdsc, session);
 886        mutex_unlock(&mdsc->mutex);
 887}
 888
 889/*
 890 * session caps
 891 */
 892
 893/*
 894 * Free preallocated cap messages assigned to this session
 895 */
 896static void cleanup_cap_releases(struct ceph_mds_session *session)
 897{
 898        struct ceph_msg *msg;
 899
 900        spin_lock(&session->s_cap_lock);
 901        while (!list_empty(&session->s_cap_releases)) {
 902                msg = list_first_entry(&session->s_cap_releases,
 903                                       struct ceph_msg, list_head);
 904                list_del_init(&msg->list_head);
 905                ceph_msg_put(msg);
 906        }
 907        while (!list_empty(&session->s_cap_releases_done)) {
 908                msg = list_first_entry(&session->s_cap_releases_done,
 909                                       struct ceph_msg, list_head);
 910                list_del_init(&msg->list_head);
 911                ceph_msg_put(msg);
 912        }
 913        spin_unlock(&session->s_cap_lock);
 914}
 915
 916/*
 917 * Helper to safely iterate over all caps associated with a session, with
 918 * special care taken to handle a racing __ceph_remove_cap().
 919 *
 920 * Caller must hold session s_mutex.
 921 */
 922static int iterate_session_caps(struct ceph_mds_session *session,
 923                                 int (*cb)(struct inode *, struct ceph_cap *,
 924                                            void *), void *arg)
 925{
 926        struct list_head *p;
 927        struct ceph_cap *cap;
 928        struct inode *inode, *last_inode = NULL;
 929        struct ceph_cap *old_cap = NULL;
 930        int ret;
 931
 932        dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
 933        spin_lock(&session->s_cap_lock);
 934        p = session->s_caps.next;
 935        while (p != &session->s_caps) {
 936                cap = list_entry(p, struct ceph_cap, session_caps);
 937                inode = igrab(&cap->ci->vfs_inode);
 938                if (!inode) {
 939                        p = p->next;
 940                        continue;
 941                }
 942                session->s_cap_iterator = cap;
 943                spin_unlock(&session->s_cap_lock);
 944
 945                if (last_inode) {
 946                        iput(last_inode);
 947                        last_inode = NULL;
 948                }
 949                if (old_cap) {
 950                        ceph_put_cap(session->s_mdsc, old_cap);
 951                        old_cap = NULL;
 952                }
 953
 954                ret = cb(inode, cap, arg);
 955                last_inode = inode;
 956
 957                spin_lock(&session->s_cap_lock);
 958                p = p->next;
 959                if (cap->ci == NULL) {
 960                        dout("iterate_session_caps  finishing cap %p removal\n",
 961                             cap);
 962                        BUG_ON(cap->session != session);
 963                        list_del_init(&cap->session_caps);
 964                        session->s_nr_caps--;
 965                        cap->session = NULL;
 966                        old_cap = cap;  /* put_cap it w/o locks held */
 967                }
 968                if (ret < 0)
 969                        goto out;
 970        }
 971        ret = 0;
 972out:
 973        session->s_cap_iterator = NULL;
 974        spin_unlock(&session->s_cap_lock);
 975
 976        if (last_inode)
 977                iput(last_inode);
 978        if (old_cap)
 979                ceph_put_cap(session->s_mdsc, old_cap);
 980
 981        return ret;
 982}
 983
 984static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
 985                                  void *arg)
 986{
 987        struct ceph_inode_info *ci = ceph_inode(inode);
 988        int drop = 0;
 989
 990        dout("removing cap %p, ci is %p, inode is %p\n",
 991             cap, ci, &ci->vfs_inode);
 992        spin_lock(&ci->i_ceph_lock);
 993        __ceph_remove_cap(cap, false);
 994        if (!__ceph_is_any_real_caps(ci)) {
 995                struct ceph_mds_client *mdsc =
 996                        ceph_sb_to_client(inode->i_sb)->mdsc;
 997
 998                spin_lock(&mdsc->cap_dirty_lock);
 999                if (!list_empty(&ci->i_dirty_item)) {
1000                        pr_info(" dropping dirty %s state for %p %lld\n",
1001                                ceph_cap_string(ci->i_dirty_caps),
1002                                inode, ceph_ino(inode));
1003                        ci->i_dirty_caps = 0;
1004                        list_del_init(&ci->i_dirty_item);
1005                        drop = 1;
1006                }
1007                if (!list_empty(&ci->i_flushing_item)) {
1008                        pr_info(" dropping dirty+flushing %s state for %p %lld\n",
1009                                ceph_cap_string(ci->i_flushing_caps),
1010                                inode, ceph_ino(inode));
1011                        ci->i_flushing_caps = 0;
1012                        list_del_init(&ci->i_flushing_item);
1013                        mdsc->num_cap_flushing--;
1014                        drop = 1;
1015                }
1016                if (drop && ci->i_wrbuffer_ref) {
1017                        pr_info(" dropping dirty data for %p %lld\n",
1018                                inode, ceph_ino(inode));
1019                        ci->i_wrbuffer_ref = 0;
1020                        ci->i_wrbuffer_ref_head = 0;
1021                        drop++;
1022                }
1023                spin_unlock(&mdsc->cap_dirty_lock);
1024        }
1025        spin_unlock(&ci->i_ceph_lock);
1026        while (drop--)
1027                iput(inode);
1028        return 0;
1029}
1030
1031/*
1032 * caller must hold session s_mutex
1033 */
1034static void remove_session_caps(struct ceph_mds_session *session)
1035{
1036        dout("remove_session_caps on %p\n", session);
1037        iterate_session_caps(session, remove_session_caps_cb, NULL);
1038
1039        spin_lock(&session->s_cap_lock);
1040        if (session->s_nr_caps > 0) {
1041                struct super_block *sb = session->s_mdsc->fsc->sb;
1042                struct inode *inode;
1043                struct ceph_cap *cap, *prev = NULL;
1044                struct ceph_vino vino;
1045                /*
1046                 * iterate_session_caps() skips inodes that are being
1047                 * deleted, we need to wait until deletions are complete.
1048                 * __wait_on_freeing_inode() is designed for the job,
1049                 * but it is not exported, so use lookup inode function
1050                 * to access it.
1051                 */
1052                while (!list_empty(&session->s_caps)) {
1053                        cap = list_entry(session->s_caps.next,
1054                                         struct ceph_cap, session_caps);
1055                        if (cap == prev)
1056                                break;
1057                        prev = cap;
1058                        vino = cap->ci->i_vino;
1059                        spin_unlock(&session->s_cap_lock);
1060
1061                        inode = ceph_find_inode(sb, vino);
1062                        iput(inode);
1063
1064                        spin_lock(&session->s_cap_lock);
1065                }
1066        }
1067        spin_unlock(&session->s_cap_lock);
1068
1069        BUG_ON(session->s_nr_caps > 0);
1070        BUG_ON(!list_empty(&session->s_cap_flushing));
1071        cleanup_cap_releases(session);
1072}
1073
1074/*
1075 * wake up any threads waiting on this session's caps.  if the cap is
1076 * old (didn't get renewed on the client reconnect), remove it now.
1077 *
1078 * caller must hold s_mutex.
1079 */
1080static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1081                              void *arg)
1082{
1083        struct ceph_inode_info *ci = ceph_inode(inode);
1084
1085        wake_up_all(&ci->i_cap_wq);
1086        if (arg) {
1087                spin_lock(&ci->i_ceph_lock);
1088                ci->i_wanted_max_size = 0;
1089                ci->i_requested_max_size = 0;
1090                spin_unlock(&ci->i_ceph_lock);
1091        }
1092        return 0;
1093}
1094
1095static void wake_up_session_caps(struct ceph_mds_session *session,
1096                                 int reconnect)
1097{
1098        dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1099        iterate_session_caps(session, wake_up_session_cb,
1100                             (void *)(unsigned long)reconnect);
1101}
1102
1103/*
1104 * Send periodic message to MDS renewing all currently held caps.  The
1105 * ack will reset the expiration for all caps from this session.
1106 *
1107 * caller holds s_mutex
1108 */
1109static int send_renew_caps(struct ceph_mds_client *mdsc,
1110                           struct ceph_mds_session *session)
1111{
1112        struct ceph_msg *msg;
1113        int state;
1114
1115        if (time_after_eq(jiffies, session->s_cap_ttl) &&
1116            time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1117                pr_info("mds%d caps stale\n", session->s_mds);
1118        session->s_renew_requested = jiffies;
1119
1120        /* do not try to renew caps until a recovering mds has reconnected
1121         * with its clients. */
1122        state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1123        if (state < CEPH_MDS_STATE_RECONNECT) {
1124                dout("send_renew_caps ignoring mds%d (%s)\n",
1125                     session->s_mds, ceph_mds_state_name(state));
1126                return 0;
1127        }
1128
1129        dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1130                ceph_mds_state_name(state));
1131        msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1132                                 ++session->s_renew_seq);
1133        if (!msg)
1134                return -ENOMEM;
1135        ceph_con_send(&session->s_con, msg);
1136        return 0;
1137}
1138
1139/*
1140 * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1141 *
1142 * Called under session->s_mutex
1143 */
1144static void renewed_caps(struct ceph_mds_client *mdsc,
1145                         struct ceph_mds_session *session, int is_renew)
1146{
1147        int was_stale;
1148        int wake = 0;
1149
1150        spin_lock(&session->s_cap_lock);
1151        was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1152
1153        session->s_cap_ttl = session->s_renew_requested +
1154                mdsc->mdsmap->m_session_timeout*HZ;
1155
1156        if (was_stale) {
1157                if (time_before(jiffies, session->s_cap_ttl)) {
1158                        pr_info("mds%d caps renewed\n", session->s_mds);
1159                        wake = 1;
1160                } else {
1161                        pr_info("mds%d caps still stale\n", session->s_mds);
1162                }
1163        }
1164        dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1165             session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1166             time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1167        spin_unlock(&session->s_cap_lock);
1168
1169        if (wake)
1170                wake_up_session_caps(session, 0);
1171}
1172
1173/*
1174 * send a session close request
1175 */
1176static int request_close_session(struct ceph_mds_client *mdsc,
1177                                 struct ceph_mds_session *session)
1178{
1179        struct ceph_msg *msg;
1180
1181        dout("request_close_session mds%d state %s seq %lld\n",
1182             session->s_mds, session_state_name(session->s_state),
1183             session->s_seq);
1184        msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1185        if (!msg)
1186                return -ENOMEM;
1187        ceph_con_send(&session->s_con, msg);
1188        return 0;
1189}
1190
1191/*
1192 * Called with s_mutex held.
1193 */
1194static int __close_session(struct ceph_mds_client *mdsc,
1195                         struct ceph_mds_session *session)
1196{
1197        if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1198                return 0;
1199        session->s_state = CEPH_MDS_SESSION_CLOSING;
1200        return request_close_session(mdsc, session);
1201}
1202
1203/*
1204 * Trim old(er) caps.
1205 *
1206 * Because we can't cache an inode without one or more caps, we do
1207 * this indirectly: if a cap is unused, we prune its aliases, at which
1208 * point the inode will hopefully get dropped to.
1209 *
1210 * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1211 * memory pressure from the MDS, though, so it needn't be perfect.
1212 */
1213static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1214{
1215        struct ceph_mds_session *session = arg;
1216        struct ceph_inode_info *ci = ceph_inode(inode);
1217        int used, oissued, mine;
1218
1219        if (session->s_trim_caps <= 0)
1220                return -1;
1221
1222        spin_lock(&ci->i_ceph_lock);
1223        mine = cap->issued | cap->implemented;
1224        used = __ceph_caps_used(ci);
1225        oissued = __ceph_caps_issued_other(ci, cap);
1226
1227        dout("trim_caps_cb %p cap %p mine %s oissued %s used %s\n",
1228             inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1229             ceph_cap_string(used));
1230        if (ci->i_dirty_caps)
1231                goto out;   /* dirty caps */
1232        if ((used & ~oissued) & mine)
1233                goto out;   /* we need these caps */
1234
1235        session->s_trim_caps--;
1236        if (oissued) {
1237                /* we aren't the only cap.. just remove us */
1238                __ceph_remove_cap(cap, true);
1239        } else {
1240                /* try to drop referring dentries */
1241                spin_unlock(&ci->i_ceph_lock);
1242                d_prune_aliases(inode);
1243                dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1244                     inode, cap, atomic_read(&inode->i_count));
1245                return 0;
1246        }
1247
1248out:
1249        spin_unlock(&ci->i_ceph_lock);
1250        return 0;
1251}
1252
1253/*
1254 * Trim session cap count down to some max number.
1255 */
1256static int trim_caps(struct ceph_mds_client *mdsc,
1257                     struct ceph_mds_session *session,
1258                     int max_caps)
1259{
1260        int trim_caps = session->s_nr_caps - max_caps;
1261
1262        dout("trim_caps mds%d start: %d / %d, trim %d\n",
1263             session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1264        if (trim_caps > 0) {
1265                session->s_trim_caps = trim_caps;
1266                iterate_session_caps(session, trim_caps_cb, session);
1267                dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1268                     session->s_mds, session->s_nr_caps, max_caps,
1269                        trim_caps - session->s_trim_caps);
1270                session->s_trim_caps = 0;
1271        }
1272        return 0;
1273}
1274
1275/*
1276 * Allocate cap_release messages.  If there is a partially full message
1277 * in the queue, try to allocate enough to cover it's remainder, so that
1278 * we can send it immediately.
1279 *
1280 * Called under s_mutex.
1281 */
1282int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
1283                          struct ceph_mds_session *session)
1284{
1285        struct ceph_msg *msg, *partial = NULL;
1286        struct ceph_mds_cap_release *head;
1287        int err = -ENOMEM;
1288        int extra = mdsc->fsc->mount_options->cap_release_safety;
1289        int num;
1290
1291        dout("add_cap_releases %p mds%d extra %d\n", session, session->s_mds,
1292             extra);
1293
1294        spin_lock(&session->s_cap_lock);
1295
1296        if (!list_empty(&session->s_cap_releases)) {
1297                msg = list_first_entry(&session->s_cap_releases,
1298                                       struct ceph_msg,
1299                                 list_head);
1300                head = msg->front.iov_base;
1301                num = le32_to_cpu(head->num);
1302                if (num) {
1303                        dout(" partial %p with (%d/%d)\n", msg, num,
1304                             (int)CEPH_CAPS_PER_RELEASE);
1305                        extra += CEPH_CAPS_PER_RELEASE - num;
1306                        partial = msg;
1307                }
1308        }
1309        while (session->s_num_cap_releases < session->s_nr_caps + extra) {
1310                spin_unlock(&session->s_cap_lock);
1311                msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE, PAGE_CACHE_SIZE,
1312                                   GFP_NOFS, false);
1313                if (!msg)
1314                        goto out_unlocked;
1315                dout("add_cap_releases %p msg %p now %d\n", session, msg,
1316                     (int)msg->front.iov_len);
1317                head = msg->front.iov_base;
1318                head->num = cpu_to_le32(0);
1319                msg->front.iov_len = sizeof(*head);
1320                spin_lock(&session->s_cap_lock);
1321                list_add(&msg->list_head, &session->s_cap_releases);
1322                session->s_num_cap_releases += CEPH_CAPS_PER_RELEASE;
1323        }
1324
1325        if (partial) {
1326                head = partial->front.iov_base;
1327                num = le32_to_cpu(head->num);
1328                dout(" queueing partial %p with %d/%d\n", partial, num,
1329                     (int)CEPH_CAPS_PER_RELEASE);
1330                list_move_tail(&partial->list_head,
1331                               &session->s_cap_releases_done);
1332                session->s_num_cap_releases -= CEPH_CAPS_PER_RELEASE - num;
1333        }
1334        err = 0;
1335        spin_unlock(&session->s_cap_lock);
1336out_unlocked:
1337        return err;
1338}
1339
1340/*
1341 * flush all dirty inode data to disk.
1342 *
1343 * returns true if we've flushed through want_flush_seq
1344 */
1345static int check_cap_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq)
1346{
1347        int mds, ret = 1;
1348
1349        dout("check_cap_flush want %lld\n", want_flush_seq);
1350        mutex_lock(&mdsc->mutex);
1351        for (mds = 0; ret && mds < mdsc->max_sessions; mds++) {
1352                struct ceph_mds_session *session = mdsc->sessions[mds];
1353
1354                if (!session)
1355                        continue;
1356                get_session(session);
1357                mutex_unlock(&mdsc->mutex);
1358
1359                mutex_lock(&session->s_mutex);
1360                if (!list_empty(&session->s_cap_flushing)) {
1361                        struct ceph_inode_info *ci =
1362                                list_entry(session->s_cap_flushing.next,
1363                                           struct ceph_inode_info,
1364                                           i_flushing_item);
1365                        struct inode *inode = &ci->vfs_inode;
1366
1367                        spin_lock(&ci->i_ceph_lock);
1368                        if (ci->i_cap_flush_seq <= want_flush_seq) {
1369                                dout("check_cap_flush still flushing %p "
1370                                     "seq %lld <= %lld to mds%d\n", inode,
1371                                     ci->i_cap_flush_seq, want_flush_seq,
1372                                     session->s_mds);
1373                                ret = 0;
1374                        }
1375                        spin_unlock(&ci->i_ceph_lock);
1376                }
1377                mutex_unlock(&session->s_mutex);
1378                ceph_put_mds_session(session);
1379
1380                if (!ret)
1381                        return ret;
1382                mutex_lock(&mdsc->mutex);
1383        }
1384
1385        mutex_unlock(&mdsc->mutex);
1386        dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq);
1387        return ret;
1388}
1389
1390/*
1391 * called under s_mutex
1392 */
1393void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1394                            struct ceph_mds_session *session)
1395{
1396        struct ceph_msg *msg;
1397
1398        dout("send_cap_releases mds%d\n", session->s_mds);
1399        spin_lock(&session->s_cap_lock);
1400        while (!list_empty(&session->s_cap_releases_done)) {
1401                msg = list_first_entry(&session->s_cap_releases_done,
1402                                 struct ceph_msg, list_head);
1403                list_del_init(&msg->list_head);
1404                spin_unlock(&session->s_cap_lock);
1405                msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1406                dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1407                ceph_con_send(&session->s_con, msg);
1408                spin_lock(&session->s_cap_lock);
1409        }
1410        spin_unlock(&session->s_cap_lock);
1411}
1412
1413static void discard_cap_releases(struct ceph_mds_client *mdsc,
1414                                 struct ceph_mds_session *session)
1415{
1416        struct ceph_msg *msg;
1417        struct ceph_mds_cap_release *head;
1418        unsigned num;
1419
1420        dout("discard_cap_releases mds%d\n", session->s_mds);
1421
1422        /* zero out the in-progress message */
1423        msg = list_first_entry(&session->s_cap_releases,
1424                               struct ceph_msg, list_head);
1425        head = msg->front.iov_base;
1426        num = le32_to_cpu(head->num);
1427        dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg, num);
1428        head->num = cpu_to_le32(0);
1429        msg->front.iov_len = sizeof(*head);
1430        session->s_num_cap_releases += num;
1431
1432        /* requeue completed messages */
1433        while (!list_empty(&session->s_cap_releases_done)) {
1434                msg = list_first_entry(&session->s_cap_releases_done,
1435                                 struct ceph_msg, list_head);
1436                list_del_init(&msg->list_head);
1437
1438                head = msg->front.iov_base;
1439                num = le32_to_cpu(head->num);
1440                dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg,
1441                     num);
1442                session->s_num_cap_releases += num;
1443                head->num = cpu_to_le32(0);
1444                msg->front.iov_len = sizeof(*head);
1445                list_add(&msg->list_head, &session->s_cap_releases);
1446        }
1447}
1448
1449/*
1450 * requests
1451 */
1452
1453/*
1454 * Create an mds request.
1455 */
1456struct ceph_mds_request *
1457ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1458{
1459        struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1460
1461        if (!req)
1462                return ERR_PTR(-ENOMEM);
1463
1464        mutex_init(&req->r_fill_mutex);
1465        req->r_mdsc = mdsc;
1466        req->r_started = jiffies;
1467        req->r_resend_mds = -1;
1468        INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1469        req->r_fmode = -1;
1470        kref_init(&req->r_kref);
1471        INIT_LIST_HEAD(&req->r_wait);
1472        init_completion(&req->r_completion);
1473        init_completion(&req->r_safe_completion);
1474        INIT_LIST_HEAD(&req->r_unsafe_item);
1475
1476        req->r_op = op;
1477        req->r_direct_mode = mode;
1478        return req;
1479}
1480
1481/*
1482 * return oldest (lowest) request, tid in request tree, 0 if none.
1483 *
1484 * called under mdsc->mutex.
1485 */
1486static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1487{
1488        if (RB_EMPTY_ROOT(&mdsc->request_tree))
1489                return NULL;
1490        return rb_entry(rb_first(&mdsc->request_tree),
1491                        struct ceph_mds_request, r_node);
1492}
1493
1494static u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1495{
1496        struct ceph_mds_request *req = __get_oldest_req(mdsc);
1497
1498        if (req)
1499                return req->r_tid;
1500        return 0;
1501}
1502
1503/*
1504 * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1505 * on build_path_from_dentry in fs/cifs/dir.c.
1506 *
1507 * If @stop_on_nosnap, generate path relative to the first non-snapped
1508 * inode.
1509 *
1510 * Encode hidden .snap dirs as a double /, i.e.
1511 *   foo/.snap/bar -> foo//bar
1512 */
1513char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1514                           int stop_on_nosnap)
1515{
1516        struct dentry *temp;
1517        char *path;
1518        int len, pos;
1519        unsigned seq;
1520
1521        if (dentry == NULL)
1522                return ERR_PTR(-EINVAL);
1523
1524retry:
1525        len = 0;
1526        seq = read_seqbegin(&rename_lock);
1527        rcu_read_lock();
1528        for (temp = dentry; !IS_ROOT(temp);) {
1529                struct inode *inode = temp->d_inode;
1530                if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1531                        len++;  /* slash only */
1532                else if (stop_on_nosnap && inode &&
1533                         ceph_snap(inode) == CEPH_NOSNAP)
1534                        break;
1535                else
1536                        len += 1 + temp->d_name.len;
1537                temp = temp->d_parent;
1538        }
1539        rcu_read_unlock();
1540        if (len)
1541                len--;  /* no leading '/' */
1542
1543        path = kmalloc(len+1, GFP_NOFS);
1544        if (path == NULL)
1545                return ERR_PTR(-ENOMEM);
1546        pos = len;
1547        path[pos] = 0;  /* trailing null */
1548        rcu_read_lock();
1549        for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1550                struct inode *inode;
1551
1552                spin_lock(&temp->d_lock);
1553                inode = temp->d_inode;
1554                if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1555                        dout("build_path path+%d: %p SNAPDIR\n",
1556                             pos, temp);
1557                } else if (stop_on_nosnap && inode &&
1558                           ceph_snap(inode) == CEPH_NOSNAP) {
1559                        spin_unlock(&temp->d_lock);
1560                        break;
1561                } else {
1562                        pos -= temp->d_name.len;
1563                        if (pos < 0) {
1564                                spin_unlock(&temp->d_lock);
1565                                break;
1566                        }
1567                        strncpy(path + pos, temp->d_name.name,
1568                                temp->d_name.len);
1569                }
1570                spin_unlock(&temp->d_lock);
1571                if (pos)
1572                        path[--pos] = '/';
1573                temp = temp->d_parent;
1574        }
1575        rcu_read_unlock();
1576        if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1577                pr_err("build_path did not end path lookup where "
1578                       "expected, namelen is %d, pos is %d\n", len, pos);
1579                /* presumably this is only possible if racing with a
1580                   rename of one of the parent directories (we can not
1581                   lock the dentries above us to prevent this, but
1582                   retrying should be harmless) */
1583                kfree(path);
1584                goto retry;
1585        }
1586
1587        *base = ceph_ino(temp->d_inode);
1588        *plen = len;
1589        dout("build_path on %p %d built %llx '%.*s'\n",
1590             dentry, d_count(dentry), *base, len, path);
1591        return path;
1592}
1593
1594static int build_dentry_path(struct dentry *dentry,
1595                             const char **ppath, int *ppathlen, u64 *pino,
1596                             int *pfreepath)
1597{
1598        char *path;
1599
1600        if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP) {
1601                *pino = ceph_ino(dentry->d_parent->d_inode);
1602                *ppath = dentry->d_name.name;
1603                *ppathlen = dentry->d_name.len;
1604                return 0;
1605        }
1606        path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1607        if (IS_ERR(path))
1608                return PTR_ERR(path);
1609        *ppath = path;
1610        *pfreepath = 1;
1611        return 0;
1612}
1613
1614static int build_inode_path(struct inode *inode,
1615                            const char **ppath, int *ppathlen, u64 *pino,
1616                            int *pfreepath)
1617{
1618        struct dentry *dentry;
1619        char *path;
1620
1621        if (ceph_snap(inode) == CEPH_NOSNAP) {
1622                *pino = ceph_ino(inode);
1623                *ppathlen = 0;
1624                return 0;
1625        }
1626        dentry = d_find_alias(inode);
1627        path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1628        dput(dentry);
1629        if (IS_ERR(path))
1630                return PTR_ERR(path);
1631        *ppath = path;
1632        *pfreepath = 1;
1633        return 0;
1634}
1635
1636/*
1637 * request arguments may be specified via an inode *, a dentry *, or
1638 * an explicit ino+path.
1639 */
1640static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1641                                  const char *rpath, u64 rino,
1642                                  const char **ppath, int *pathlen,
1643                                  u64 *ino, int *freepath)
1644{
1645        int r = 0;
1646
1647        if (rinode) {
1648                r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1649                dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1650                     ceph_snap(rinode));
1651        } else if (rdentry) {
1652                r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1653                dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1654                     *ppath);
1655        } else if (rpath || rino) {
1656                *ino = rino;
1657                *ppath = rpath;
1658                *pathlen = rpath ? strlen(rpath) : 0;
1659                dout(" path %.*s\n", *pathlen, rpath);
1660        }
1661
1662        return r;
1663}
1664
1665/*
1666 * called under mdsc->mutex
1667 */
1668static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1669                                               struct ceph_mds_request *req,
1670                                               int mds)
1671{
1672        struct ceph_msg *msg;
1673        struct ceph_mds_request_head *head;
1674        const char *path1 = NULL;
1675        const char *path2 = NULL;
1676        u64 ino1 = 0, ino2 = 0;
1677        int pathlen1 = 0, pathlen2 = 0;
1678        int freepath1 = 0, freepath2 = 0;
1679        int len;
1680        u16 releases;
1681        void *p, *end;
1682        int ret;
1683
1684        ret = set_request_path_attr(req->r_inode, req->r_dentry,
1685                              req->r_path1, req->r_ino1.ino,
1686                              &path1, &pathlen1, &ino1, &freepath1);
1687        if (ret < 0) {
1688                msg = ERR_PTR(ret);
1689                goto out;
1690        }
1691
1692        ret = set_request_path_attr(NULL, req->r_old_dentry,
1693                              req->r_path2, req->r_ino2.ino,
1694                              &path2, &pathlen2, &ino2, &freepath2);
1695        if (ret < 0) {
1696                msg = ERR_PTR(ret);
1697                goto out_free1;
1698        }
1699
1700        len = sizeof(*head) +
1701                pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64));
1702
1703        /* calculate (max) length for cap releases */
1704        len += sizeof(struct ceph_mds_request_release) *
1705                (!!req->r_inode_drop + !!req->r_dentry_drop +
1706                 !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1707        if (req->r_dentry_drop)
1708                len += req->r_dentry->d_name.len;
1709        if (req->r_old_dentry_drop)
1710                len += req->r_old_dentry->d_name.len;
1711
1712        msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1713        if (!msg) {
1714                msg = ERR_PTR(-ENOMEM);
1715                goto out_free2;
1716        }
1717
1718        msg->hdr.tid = cpu_to_le64(req->r_tid);
1719
1720        head = msg->front.iov_base;
1721        p = msg->front.iov_base + sizeof(*head);
1722        end = msg->front.iov_base + msg->front.iov_len;
1723
1724        head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1725        head->op = cpu_to_le32(req->r_op);
1726        head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1727        head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1728        head->args = req->r_args;
1729
1730        ceph_encode_filepath(&p, end, ino1, path1);
1731        ceph_encode_filepath(&p, end, ino2, path2);
1732
1733        /* make note of release offset, in case we need to replay */
1734        req->r_request_release_offset = p - msg->front.iov_base;
1735
1736        /* cap releases */
1737        releases = 0;
1738        if (req->r_inode_drop)
1739                releases += ceph_encode_inode_release(&p,
1740                      req->r_inode ? req->r_inode : req->r_dentry->d_inode,
1741                      mds, req->r_inode_drop, req->r_inode_unless, 0);
1742        if (req->r_dentry_drop)
1743                releases += ceph_encode_dentry_release(&p, req->r_dentry,
1744                       mds, req->r_dentry_drop, req->r_dentry_unless);
1745        if (req->r_old_dentry_drop)
1746                releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1747                       mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1748        if (req->r_old_inode_drop)
1749                releases += ceph_encode_inode_release(&p,
1750                      req->r_old_dentry->d_inode,
1751                      mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1752        head->num_releases = cpu_to_le16(releases);
1753
1754        BUG_ON(p > end);
1755        msg->front.iov_len = p - msg->front.iov_base;
1756        msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1757
1758        if (req->r_data_len) {
1759                /* outbound data set only by ceph_sync_setxattr() */
1760                BUG_ON(!req->r_pages);
1761                ceph_msg_data_add_pages(msg, req->r_pages, req->r_data_len, 0);
1762        }
1763
1764        msg->hdr.data_len = cpu_to_le32(req->r_data_len);
1765        msg->hdr.data_off = cpu_to_le16(0);
1766
1767out_free2:
1768        if (freepath2)
1769                kfree((char *)path2);
1770out_free1:
1771        if (freepath1)
1772                kfree((char *)path1);
1773out:
1774        return msg;
1775}
1776
1777/*
1778 * called under mdsc->mutex if error, under no mutex if
1779 * success.
1780 */
1781static void complete_request(struct ceph_mds_client *mdsc,
1782                             struct ceph_mds_request *req)
1783{
1784        if (req->r_callback)
1785                req->r_callback(mdsc, req);
1786        else
1787                complete_all(&req->r_completion);
1788}
1789
1790/*
1791 * called under mdsc->mutex
1792 */
1793static int __prepare_send_request(struct ceph_mds_client *mdsc,
1794                                  struct ceph_mds_request *req,
1795                                  int mds)
1796{
1797        struct ceph_mds_request_head *rhead;
1798        struct ceph_msg *msg;
1799        int flags = 0;
1800
1801        req->r_attempts++;
1802        if (req->r_inode) {
1803                struct ceph_cap *cap =
1804                        ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
1805
1806                if (cap)
1807                        req->r_sent_on_mseq = cap->mseq;
1808                else
1809                        req->r_sent_on_mseq = -1;
1810        }
1811        dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
1812             req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
1813
1814        if (req->r_got_unsafe) {
1815                /*
1816                 * Replay.  Do not regenerate message (and rebuild
1817                 * paths, etc.); just use the original message.
1818                 * Rebuilding paths will break for renames because
1819                 * d_move mangles the src name.
1820                 */
1821                msg = req->r_request;
1822                rhead = msg->front.iov_base;
1823
1824                flags = le32_to_cpu(rhead->flags);
1825                flags |= CEPH_MDS_FLAG_REPLAY;
1826                rhead->flags = cpu_to_le32(flags);
1827
1828                if (req->r_target_inode)
1829                        rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
1830
1831                rhead->num_retry = req->r_attempts - 1;
1832
1833                /* remove cap/dentry releases from message */
1834                rhead->num_releases = 0;
1835                msg->hdr.front_len = cpu_to_le32(req->r_request_release_offset);
1836                msg->front.iov_len = req->r_request_release_offset;
1837                return 0;
1838        }
1839
1840        if (req->r_request) {
1841                ceph_msg_put(req->r_request);
1842                req->r_request = NULL;
1843        }
1844        msg = create_request_message(mdsc, req, mds);
1845        if (IS_ERR(msg)) {
1846                req->r_err = PTR_ERR(msg);
1847                complete_request(mdsc, req);
1848                return PTR_ERR(msg);
1849        }
1850        req->r_request = msg;
1851
1852        rhead = msg->front.iov_base;
1853        rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
1854        if (req->r_got_unsafe)
1855                flags |= CEPH_MDS_FLAG_REPLAY;
1856        if (req->r_locked_dir)
1857                flags |= CEPH_MDS_FLAG_WANT_DENTRY;
1858        rhead->flags = cpu_to_le32(flags);
1859        rhead->num_fwd = req->r_num_fwd;
1860        rhead->num_retry = req->r_attempts - 1;
1861        rhead->ino = 0;
1862
1863        dout(" r_locked_dir = %p\n", req->r_locked_dir);
1864        return 0;
1865}
1866
1867/*
1868 * send request, or put it on the appropriate wait list.
1869 */
1870static int __do_request(struct ceph_mds_client *mdsc,
1871                        struct ceph_mds_request *req)
1872{
1873        struct ceph_mds_session *session = NULL;
1874        int mds = -1;
1875        int err = -EAGAIN;
1876
1877        if (req->r_err || req->r_got_result) {
1878                if (req->r_aborted)
1879                        __unregister_request(mdsc, req);
1880                goto out;
1881        }
1882
1883        if (req->r_timeout &&
1884            time_after_eq(jiffies, req->r_started + req->r_timeout)) {
1885                dout("do_request timed out\n");
1886                err = -EIO;
1887                goto finish;
1888        }
1889
1890        put_request_session(req);
1891
1892        mds = __choose_mds(mdsc, req);
1893        if (mds < 0 ||
1894            ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
1895                dout("do_request no mds or not active, waiting for map\n");
1896                list_add(&req->r_wait, &mdsc->waiting_for_map);
1897                goto out;
1898        }
1899
1900        /* get, open session */
1901        session = __ceph_lookup_mds_session(mdsc, mds);
1902        if (!session) {
1903                session = register_session(mdsc, mds);
1904                if (IS_ERR(session)) {
1905                        err = PTR_ERR(session);
1906                        goto finish;
1907                }
1908        }
1909        req->r_session = get_session(session);
1910
1911        dout("do_request mds%d session %p state %s\n", mds, session,
1912             session_state_name(session->s_state));
1913        if (session->s_state != CEPH_MDS_SESSION_OPEN &&
1914            session->s_state != CEPH_MDS_SESSION_HUNG) {
1915                if (session->s_state == CEPH_MDS_SESSION_NEW ||
1916                    session->s_state == CEPH_MDS_SESSION_CLOSING)
1917                        __open_session(mdsc, session);
1918                list_add(&req->r_wait, &session->s_waiting);
1919                goto out_session;
1920        }
1921
1922        /* send request */
1923        req->r_resend_mds = -1;   /* forget any previous mds hint */
1924
1925        if (req->r_request_started == 0)   /* note request start time */
1926                req->r_request_started = jiffies;
1927
1928        err = __prepare_send_request(mdsc, req, mds);
1929        if (!err) {
1930                ceph_msg_get(req->r_request);
1931                ceph_con_send(&session->s_con, req->r_request);
1932        }
1933
1934out_session:
1935        ceph_put_mds_session(session);
1936out:
1937        return err;
1938
1939finish:
1940        req->r_err = err;
1941        complete_request(mdsc, req);
1942        goto out;
1943}
1944
1945/*
1946 * called under mdsc->mutex
1947 */
1948static void __wake_requests(struct ceph_mds_client *mdsc,
1949                            struct list_head *head)
1950{
1951        struct ceph_mds_request *req;
1952        LIST_HEAD(tmp_list);
1953
1954        list_splice_init(head, &tmp_list);
1955
1956        while (!list_empty(&tmp_list)) {
1957                req = list_entry(tmp_list.next,
1958                                 struct ceph_mds_request, r_wait);
1959                list_del_init(&req->r_wait);
1960                dout(" wake request %p tid %llu\n", req, req->r_tid);
1961                __do_request(mdsc, req);
1962        }
1963}
1964
1965/*
1966 * Wake up threads with requests pending for @mds, so that they can
1967 * resubmit their requests to a possibly different mds.
1968 */
1969static void kick_requests(struct ceph_mds_client *mdsc, int mds)
1970{
1971        struct ceph_mds_request *req;
1972        struct rb_node *p;
1973
1974        dout("kick_requests mds%d\n", mds);
1975        for (p = rb_first(&mdsc->request_tree); p; p = rb_next(p)) {
1976                req = rb_entry(p, struct ceph_mds_request, r_node);
1977                if (req->r_got_unsafe)
1978                        continue;
1979                if (req->r_session &&
1980                    req->r_session->s_mds == mds) {
1981                        dout(" kicking tid %llu\n", req->r_tid);
1982                        __do_request(mdsc, req);
1983                }
1984        }
1985}
1986
1987void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
1988                              struct ceph_mds_request *req)
1989{
1990        dout("submit_request on %p\n", req);
1991        mutex_lock(&mdsc->mutex);
1992        __register_request(mdsc, req, NULL);
1993        __do_request(mdsc, req);
1994        mutex_unlock(&mdsc->mutex);
1995}
1996
1997/*
1998 * Synchrously perform an mds request.  Take care of all of the
1999 * session setup, forwarding, retry details.
2000 */
2001int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
2002                         struct inode *dir,
2003                         struct ceph_mds_request *req)
2004{
2005        int err;
2006
2007        dout("do_request on %p\n", req);
2008
2009        /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
2010        if (req->r_inode)
2011                ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
2012        if (req->r_locked_dir)
2013                ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
2014        if (req->r_old_dentry)
2015                ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
2016                                  CEPH_CAP_PIN);
2017
2018        /* issue */
2019        mutex_lock(&mdsc->mutex);
2020        __register_request(mdsc, req, dir);
2021        __do_request(mdsc, req);
2022
2023        if (req->r_err) {
2024                err = req->r_err;
2025                __unregister_request(mdsc, req);
2026                dout("do_request early error %d\n", err);
2027                goto out;
2028        }
2029
2030        /* wait */
2031        mutex_unlock(&mdsc->mutex);
2032        dout("do_request waiting\n");
2033        if (req->r_timeout) {
2034                err = (long)wait_for_completion_killable_timeout(
2035                        &req->r_completion, req->r_timeout);
2036                if (err == 0)
2037                        err = -EIO;
2038        } else {
2039                err = wait_for_completion_killable(&req->r_completion);
2040        }
2041        dout("do_request waited, got %d\n", err);
2042        mutex_lock(&mdsc->mutex);
2043
2044        /* only abort if we didn't race with a real reply */
2045        if (req->r_got_result) {
2046                err = le32_to_cpu(req->r_reply_info.head->result);
2047        } else if (err < 0) {
2048                dout("aborted request %lld with %d\n", req->r_tid, err);
2049
2050                /*
2051                 * ensure we aren't running concurrently with
2052                 * ceph_fill_trace or ceph_readdir_prepopulate, which
2053                 * rely on locks (dir mutex) held by our caller.
2054                 */
2055                mutex_lock(&req->r_fill_mutex);
2056                req->r_err = err;
2057                req->r_aborted = true;
2058                mutex_unlock(&req->r_fill_mutex);
2059
2060                if (req->r_locked_dir &&
2061                    (req->r_op & CEPH_MDS_OP_WRITE))
2062                        ceph_invalidate_dir_request(req);
2063        } else {
2064                err = req->r_err;
2065        }
2066
2067out:
2068        mutex_unlock(&mdsc->mutex);
2069        dout("do_request %p done, result %d\n", req, err);
2070        return err;
2071}
2072
2073/*
2074 * Invalidate dir's completeness, dentry lease state on an aborted MDS
2075 * namespace request.
2076 */
2077void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2078{
2079        struct inode *inode = req->r_locked_dir;
2080
2081        dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2082
2083        ceph_dir_clear_complete(inode);
2084        if (req->r_dentry)
2085                ceph_invalidate_dentry_lease(req->r_dentry);
2086        if (req->r_old_dentry)
2087                ceph_invalidate_dentry_lease(req->r_old_dentry);
2088}
2089
2090/*
2091 * Handle mds reply.
2092 *
2093 * We take the session mutex and parse and process the reply immediately.
2094 * This preserves the logical ordering of replies, capabilities, etc., sent
2095 * by the MDS as they are applied to our local cache.
2096 */
2097static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2098{
2099        struct ceph_mds_client *mdsc = session->s_mdsc;
2100        struct ceph_mds_request *req;
2101        struct ceph_mds_reply_head *head = msg->front.iov_base;
2102        struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2103        u64 tid;
2104        int err, result;
2105        int mds = session->s_mds;
2106
2107        if (msg->front.iov_len < sizeof(*head)) {
2108                pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2109                ceph_msg_dump(msg);
2110                return;
2111        }
2112
2113        /* get request, session */
2114        tid = le64_to_cpu(msg->hdr.tid);
2115        mutex_lock(&mdsc->mutex);
2116        req = __lookup_request(mdsc, tid);
2117        if (!req) {
2118                dout("handle_reply on unknown tid %llu\n", tid);
2119                mutex_unlock(&mdsc->mutex);
2120                return;
2121        }
2122        dout("handle_reply %p\n", req);
2123
2124        /* correct session? */
2125        if (req->r_session != session) {
2126                pr_err("mdsc_handle_reply got %llu on session mds%d"
2127                       " not mds%d\n", tid, session->s_mds,
2128                       req->r_session ? req->r_session->s_mds : -1);
2129                mutex_unlock(&mdsc->mutex);
2130                goto out;
2131        }
2132
2133        /* dup? */
2134        if ((req->r_got_unsafe && !head->safe) ||
2135            (req->r_got_safe && head->safe)) {
2136                pr_warning("got a dup %s reply on %llu from mds%d\n",
2137                           head->safe ? "safe" : "unsafe", tid, mds);
2138                mutex_unlock(&mdsc->mutex);
2139                goto out;
2140        }
2141        if (req->r_got_safe && !head->safe) {
2142                pr_warning("got unsafe after safe on %llu from mds%d\n",
2143                           tid, mds);
2144                mutex_unlock(&mdsc->mutex);
2145                goto out;
2146        }
2147
2148        result = le32_to_cpu(head->result);
2149
2150        /*
2151         * Handle an ESTALE
2152         * if we're not talking to the authority, send to them
2153         * if the authority has changed while we weren't looking,
2154         * send to new authority
2155         * Otherwise we just have to return an ESTALE
2156         */
2157        if (result == -ESTALE) {
2158                dout("got ESTALE on request %llu", req->r_tid);
2159                if (!req->r_inode) {
2160                        /* do nothing; not an authority problem */
2161                } else if (req->r_direct_mode != USE_AUTH_MDS) {
2162                        dout("not using auth, setting for that now");
2163                        req->r_direct_mode = USE_AUTH_MDS;
2164                        __do_request(mdsc, req);
2165                        mutex_unlock(&mdsc->mutex);
2166                        goto out;
2167                } else  {
2168                        struct ceph_inode_info *ci = ceph_inode(req->r_inode);
2169                        struct ceph_cap *cap = NULL;
2170
2171                        if (req->r_session)
2172                                cap = ceph_get_cap_for_mds(ci,
2173                                                   req->r_session->s_mds);
2174
2175                        dout("already using auth");
2176                        if ((!cap || cap != ci->i_auth_cap) ||
2177                            (cap->mseq != req->r_sent_on_mseq)) {
2178                                dout("but cap changed, so resending");
2179                                __do_request(mdsc, req);
2180                                mutex_unlock(&mdsc->mutex);
2181                                goto out;
2182                        }
2183                }
2184                dout("have to return ESTALE on request %llu", req->r_tid);
2185        }
2186
2187
2188        if (head->safe) {
2189                req->r_got_safe = true;
2190                __unregister_request(mdsc, req);
2191
2192                if (req->r_got_unsafe) {
2193                        /*
2194                         * We already handled the unsafe response, now do the
2195                         * cleanup.  No need to examine the response; the MDS
2196                         * doesn't include any result info in the safe
2197                         * response.  And even if it did, there is nothing
2198                         * useful we could do with a revised return value.
2199                         */
2200                        dout("got safe reply %llu, mds%d\n", tid, mds);
2201                        list_del_init(&req->r_unsafe_item);
2202
2203                        /* last unsafe request during umount? */
2204                        if (mdsc->stopping && !__get_oldest_req(mdsc))
2205                                complete_all(&mdsc->safe_umount_waiters);
2206                        mutex_unlock(&mdsc->mutex);
2207                        goto out;
2208                }
2209        } else {
2210                req->r_got_unsafe = true;
2211                list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2212        }
2213
2214        dout("handle_reply tid %lld result %d\n", tid, result);
2215        rinfo = &req->r_reply_info;
2216        err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2217        mutex_unlock(&mdsc->mutex);
2218
2219        mutex_lock(&session->s_mutex);
2220        if (err < 0) {
2221                pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2222                ceph_msg_dump(msg);
2223                goto out_err;
2224        }
2225
2226        /* snap trace */
2227        if (rinfo->snapblob_len) {
2228                down_write(&mdsc->snap_rwsem);
2229                ceph_update_snap_trace(mdsc, rinfo->snapblob,
2230                               rinfo->snapblob + rinfo->snapblob_len,
2231                               le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP);
2232                downgrade_write(&mdsc->snap_rwsem);
2233        } else {
2234                down_read(&mdsc->snap_rwsem);
2235        }
2236
2237        /* insert trace into our cache */
2238        mutex_lock(&req->r_fill_mutex);
2239        err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2240        if (err == 0) {
2241                if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2242                                    req->r_op == CEPH_MDS_OP_LSSNAP))
2243                        ceph_readdir_prepopulate(req, req->r_session);
2244                ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2245        }
2246        mutex_unlock(&req->r_fill_mutex);
2247
2248        up_read(&mdsc->snap_rwsem);
2249out_err:
2250        mutex_lock(&mdsc->mutex);
2251        if (!req->r_aborted) {
2252                if (err) {
2253                        req->r_err = err;
2254                } else {
2255                        req->r_reply = msg;
2256                        ceph_msg_get(msg);
2257                        req->r_got_result = true;
2258                }
2259        } else {
2260                dout("reply arrived after request %lld was aborted\n", tid);
2261        }
2262        mutex_unlock(&mdsc->mutex);
2263
2264        ceph_add_cap_releases(mdsc, req->r_session);
2265        mutex_unlock(&session->s_mutex);
2266
2267        /* kick calling process */
2268        complete_request(mdsc, req);
2269out:
2270        ceph_mdsc_put_request(req);
2271        return;
2272}
2273
2274
2275
2276/*
2277 * handle mds notification that our request has been forwarded.
2278 */
2279static void handle_forward(struct ceph_mds_client *mdsc,
2280                           struct ceph_mds_session *session,
2281                           struct ceph_msg *msg)
2282{
2283        struct ceph_mds_request *req;
2284        u64 tid = le64_to_cpu(msg->hdr.tid);
2285        u32 next_mds;
2286        u32 fwd_seq;
2287        int err = -EINVAL;
2288        void *p = msg->front.iov_base;
2289        void *end = p + msg->front.iov_len;
2290
2291        ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2292        next_mds = ceph_decode_32(&p);
2293        fwd_seq = ceph_decode_32(&p);
2294
2295        mutex_lock(&mdsc->mutex);
2296        req = __lookup_request(mdsc, tid);
2297        if (!req) {
2298                dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2299                goto out;  /* dup reply? */
2300        }
2301
2302        if (req->r_aborted) {
2303                dout("forward tid %llu aborted, unregistering\n", tid);
2304                __unregister_request(mdsc, req);
2305        } else if (fwd_seq <= req->r_num_fwd) {
2306                dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2307                     tid, next_mds, req->r_num_fwd, fwd_seq);
2308        } else {
2309                /* resend. forward race not possible; mds would drop */
2310                dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2311                BUG_ON(req->r_err);
2312                BUG_ON(req->r_got_result);
2313                req->r_num_fwd = fwd_seq;
2314                req->r_resend_mds = next_mds;
2315                put_request_session(req);
2316                __do_request(mdsc, req);
2317        }
2318        ceph_mdsc_put_request(req);
2319out:
2320        mutex_unlock(&mdsc->mutex);
2321        return;
2322
2323bad:
2324        pr_err("mdsc_handle_forward decode error err=%d\n", err);
2325}
2326
2327/*
2328 * handle a mds session control message
2329 */
2330static void handle_session(struct ceph_mds_session *session,
2331                           struct ceph_msg *msg)
2332{
2333        struct ceph_mds_client *mdsc = session->s_mdsc;
2334        u32 op;
2335        u64 seq;
2336        int mds = session->s_mds;
2337        struct ceph_mds_session_head *h = msg->front.iov_base;
2338        int wake = 0;
2339
2340        /* decode */
2341        if (msg->front.iov_len != sizeof(*h))
2342                goto bad;
2343        op = le32_to_cpu(h->op);
2344        seq = le64_to_cpu(h->seq);
2345
2346        mutex_lock(&mdsc->mutex);
2347        if (op == CEPH_SESSION_CLOSE)
2348                __unregister_session(mdsc, session);
2349        /* FIXME: this ttl calculation is generous */
2350        session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2351        mutex_unlock(&mdsc->mutex);
2352
2353        mutex_lock(&session->s_mutex);
2354
2355        dout("handle_session mds%d %s %p state %s seq %llu\n",
2356             mds, ceph_session_op_name(op), session,
2357             session_state_name(session->s_state), seq);
2358
2359        if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2360                session->s_state = CEPH_MDS_SESSION_OPEN;
2361                pr_info("mds%d came back\n", session->s_mds);
2362        }
2363
2364        switch (op) {
2365        case CEPH_SESSION_OPEN:
2366                if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2367                        pr_info("mds%d reconnect success\n", session->s_mds);
2368                session->s_state = CEPH_MDS_SESSION_OPEN;
2369                renewed_caps(mdsc, session, 0);
2370                wake = 1;
2371                if (mdsc->stopping)
2372                        __close_session(mdsc, session);
2373                break;
2374
2375        case CEPH_SESSION_RENEWCAPS:
2376                if (session->s_renew_seq == seq)
2377                        renewed_caps(mdsc, session, 1);
2378                break;
2379
2380        case CEPH_SESSION_CLOSE:
2381                if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2382                        pr_info("mds%d reconnect denied\n", session->s_mds);
2383                remove_session_caps(session);
2384                wake = 1; /* for good measure */
2385                wake_up_all(&mdsc->session_close_wq);
2386                kick_requests(mdsc, mds);
2387                break;
2388
2389        case CEPH_SESSION_STALE:
2390                pr_info("mds%d caps went stale, renewing\n",
2391                        session->s_mds);
2392                spin_lock(&session->s_gen_ttl_lock);
2393                session->s_cap_gen++;
2394                session->s_cap_ttl = jiffies - 1;
2395                spin_unlock(&session->s_gen_ttl_lock);
2396                send_renew_caps(mdsc, session);
2397                break;
2398
2399        case CEPH_SESSION_RECALL_STATE:
2400                trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2401                break;
2402
2403        default:
2404                pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2405                WARN_ON(1);
2406        }
2407
2408        mutex_unlock(&session->s_mutex);
2409        if (wake) {
2410                mutex_lock(&mdsc->mutex);
2411                __wake_requests(mdsc, &session->s_waiting);
2412                mutex_unlock(&mdsc->mutex);
2413        }
2414        return;
2415
2416bad:
2417        pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2418               (int)msg->front.iov_len);
2419        ceph_msg_dump(msg);
2420        return;
2421}
2422
2423
2424/*
2425 * called under session->mutex.
2426 */
2427static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2428                                   struct ceph_mds_session *session)
2429{
2430        struct ceph_mds_request *req, *nreq;
2431        int err;
2432
2433        dout("replay_unsafe_requests mds%d\n", session->s_mds);
2434
2435        mutex_lock(&mdsc->mutex);
2436        list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2437                err = __prepare_send_request(mdsc, req, session->s_mds);
2438                if (!err) {
2439                        ceph_msg_get(req->r_request);
2440                        ceph_con_send(&session->s_con, req->r_request);
2441                }
2442        }
2443        mutex_unlock(&mdsc->mutex);
2444}
2445
2446/*
2447 * Encode information about a cap for a reconnect with the MDS.
2448 */
2449static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2450                          void *arg)
2451{
2452        union {
2453                struct ceph_mds_cap_reconnect v2;
2454                struct ceph_mds_cap_reconnect_v1 v1;
2455        } rec;
2456        size_t reclen;
2457        struct ceph_inode_info *ci;
2458        struct ceph_reconnect_state *recon_state = arg;
2459        struct ceph_pagelist *pagelist = recon_state->pagelist;
2460        char *path;
2461        int pathlen, err;
2462        u64 pathbase;
2463        struct dentry *dentry;
2464
2465        ci = cap->ci;
2466
2467        dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2468             inode, ceph_vinop(inode), cap, cap->cap_id,
2469             ceph_cap_string(cap->issued));
2470        err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2471        if (err)
2472                return err;
2473
2474        dentry = d_find_alias(inode);
2475        if (dentry) {
2476                path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2477                if (IS_ERR(path)) {
2478                        err = PTR_ERR(path);
2479                        goto out_dput;
2480                }
2481        } else {
2482                path = NULL;
2483                pathlen = 0;
2484        }
2485        err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2486        if (err)
2487                goto out_free;
2488
2489        spin_lock(&ci->i_ceph_lock);
2490        cap->seq = 0;        /* reset cap seq */
2491        cap->issue_seq = 0;  /* and issue_seq */
2492        cap->mseq = 0;       /* and migrate_seq */
2493        cap->cap_gen = cap->session->s_cap_gen;
2494
2495        if (recon_state->flock) {
2496                rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2497                rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2498                rec.v2.issued = cpu_to_le32(cap->issued);
2499                rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2500                rec.v2.pathbase = cpu_to_le64(pathbase);
2501                rec.v2.flock_len = 0;
2502                reclen = sizeof(rec.v2);
2503        } else {
2504                rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2505                rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2506                rec.v1.issued = cpu_to_le32(cap->issued);
2507                rec.v1.size = cpu_to_le64(inode->i_size);
2508                ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2509                ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2510                rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2511                rec.v1.pathbase = cpu_to_le64(pathbase);
2512                reclen = sizeof(rec.v1);
2513        }
2514        spin_unlock(&ci->i_ceph_lock);
2515
2516        if (recon_state->flock) {
2517                int num_fcntl_locks, num_flock_locks;
2518                struct ceph_filelock *flocks;
2519
2520encode_again:
2521                spin_lock(&inode->i_lock);
2522                ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2523                spin_unlock(&inode->i_lock);
2524                flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2525                                 sizeof(struct ceph_filelock), GFP_NOFS);
2526                if (!flocks) {
2527                        err = -ENOMEM;
2528                        goto out_free;
2529                }
2530                spin_lock(&inode->i_lock);
2531                err = ceph_encode_locks_to_buffer(inode, flocks,
2532                                                  num_fcntl_locks,
2533                                                  num_flock_locks);
2534                spin_unlock(&inode->i_lock);
2535                if (err) {
2536                        kfree(flocks);
2537                        if (err == -ENOSPC)
2538                                goto encode_again;
2539                        goto out_free;
2540                }
2541                /*
2542                 * number of encoded locks is stable, so copy to pagelist
2543                 */
2544                rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2545                                    (num_fcntl_locks+num_flock_locks) *
2546                                    sizeof(struct ceph_filelock));
2547                err = ceph_pagelist_append(pagelist, &rec, reclen);
2548                if (!err)
2549                        err = ceph_locks_to_pagelist(flocks, pagelist,
2550                                                     num_fcntl_locks,
2551                                                     num_flock_locks);
2552                kfree(flocks);
2553        } else {
2554                err = ceph_pagelist_append(pagelist, &rec, reclen);
2555        }
2556
2557        recon_state->nr_caps++;
2558out_free:
2559        kfree(path);
2560out_dput:
2561        dput(dentry);
2562        return err;
2563}
2564
2565
2566/*
2567 * If an MDS fails and recovers, clients need to reconnect in order to
2568 * reestablish shared state.  This includes all caps issued through
2569 * this session _and_ the snap_realm hierarchy.  Because it's not
2570 * clear which snap realms the mds cares about, we send everything we
2571 * know about.. that ensures we'll then get any new info the
2572 * recovering MDS might have.
2573 *
2574 * This is a relatively heavyweight operation, but it's rare.
2575 *
2576 * called with mdsc->mutex held.
2577 */
2578static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2579                               struct ceph_mds_session *session)
2580{
2581        struct ceph_msg *reply;
2582        struct rb_node *p;
2583        int mds = session->s_mds;
2584        int err = -ENOMEM;
2585        int s_nr_caps;
2586        struct ceph_pagelist *pagelist;
2587        struct ceph_reconnect_state recon_state;
2588
2589        pr_info("mds%d reconnect start\n", mds);
2590
2591        pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2592        if (!pagelist)
2593                goto fail_nopagelist;
2594        ceph_pagelist_init(pagelist);
2595
2596        reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2597        if (!reply)
2598                goto fail_nomsg;
2599
2600        mutex_lock(&session->s_mutex);
2601        session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2602        session->s_seq = 0;
2603
2604        ceph_con_close(&session->s_con);
2605        ceph_con_open(&session->s_con,
2606                      CEPH_ENTITY_TYPE_MDS, mds,
2607                      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2608
2609        /* replay unsafe requests */
2610        replay_unsafe_requests(mdsc, session);
2611
2612        down_read(&mdsc->snap_rwsem);
2613
2614        dout("session %p state %s\n", session,
2615             session_state_name(session->s_state));
2616
2617        spin_lock(&session->s_gen_ttl_lock);
2618        session->s_cap_gen++;
2619        spin_unlock(&session->s_gen_ttl_lock);
2620
2621        spin_lock(&session->s_cap_lock);
2622        /*
2623         * notify __ceph_remove_cap() that we are composing cap reconnect.
2624         * If a cap get released before being added to the cap reconnect,
2625         * __ceph_remove_cap() should skip queuing cap release.
2626         */
2627        session->s_cap_reconnect = 1;
2628        /* drop old cap expires; we're about to reestablish that state */
2629        discard_cap_releases(mdsc, session);
2630        spin_unlock(&session->s_cap_lock);
2631
2632        /* traverse this session's caps */
2633        s_nr_caps = session->s_nr_caps;
2634        err = ceph_pagelist_encode_32(pagelist, s_nr_caps);
2635        if (err)
2636                goto fail;
2637
2638        recon_state.nr_caps = 0;
2639        recon_state.pagelist = pagelist;
2640        recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2641        err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2642        if (err < 0)
2643                goto fail;
2644
2645        spin_lock(&session->s_cap_lock);
2646        session->s_cap_reconnect = 0;
2647        spin_unlock(&session->s_cap_lock);
2648
2649        /*
2650         * snaprealms.  we provide mds with the ino, seq (version), and
2651         * parent for all of our realms.  If the mds has any newer info,
2652         * it will tell us.
2653         */
2654        for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2655                struct ceph_snap_realm *realm =
2656                        rb_entry(p, struct ceph_snap_realm, node);
2657                struct ceph_mds_snaprealm_reconnect sr_rec;
2658
2659                dout(" adding snap realm %llx seq %lld parent %llx\n",
2660                     realm->ino, realm->seq, realm->parent_ino);
2661                sr_rec.ino = cpu_to_le64(realm->ino);
2662                sr_rec.seq = cpu_to_le64(realm->seq);
2663                sr_rec.parent = cpu_to_le64(realm->parent_ino);
2664                err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2665                if (err)
2666                        goto fail;
2667        }
2668
2669        if (recon_state.flock)
2670                reply->hdr.version = cpu_to_le16(2);
2671
2672        /* raced with cap release? */
2673        if (s_nr_caps != recon_state.nr_caps) {
2674                struct page *page = list_first_entry(&pagelist->head,
2675                                                     struct page, lru);
2676                __le32 *addr = kmap_atomic(page);
2677                *addr = cpu_to_le32(recon_state.nr_caps);
2678                kunmap_atomic(addr);
2679        }
2680
2681        reply->hdr.data_len = cpu_to_le32(pagelist->length);
2682        ceph_msg_data_add_pagelist(reply, pagelist);
2683        ceph_con_send(&session->s_con, reply);
2684
2685        mutex_unlock(&session->s_mutex);
2686
2687        mutex_lock(&mdsc->mutex);
2688        __wake_requests(mdsc, &session->s_waiting);
2689        mutex_unlock(&mdsc->mutex);
2690
2691        up_read(&mdsc->snap_rwsem);
2692        return;
2693
2694fail:
2695        ceph_msg_put(reply);
2696        up_read(&mdsc->snap_rwsem);
2697        mutex_unlock(&session->s_mutex);
2698fail_nomsg:
2699        ceph_pagelist_release(pagelist);
2700        kfree(pagelist);
2701fail_nopagelist:
2702        pr_err("error %d preparing reconnect for mds%d\n", err, mds);
2703        return;
2704}
2705
2706
2707/*
2708 * compare old and new mdsmaps, kicking requests
2709 * and closing out old connections as necessary
2710 *
2711 * called under mdsc->mutex.
2712 */
2713static void check_new_map(struct ceph_mds_client *mdsc,
2714                          struct ceph_mdsmap *newmap,
2715                          struct ceph_mdsmap *oldmap)
2716{
2717        int i;
2718        int oldstate, newstate;
2719        struct ceph_mds_session *s;
2720
2721        dout("check_new_map new %u old %u\n",
2722             newmap->m_epoch, oldmap->m_epoch);
2723
2724        for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
2725                if (mdsc->sessions[i] == NULL)
2726                        continue;
2727                s = mdsc->sessions[i];
2728                oldstate = ceph_mdsmap_get_state(oldmap, i);
2729                newstate = ceph_mdsmap_get_state(newmap, i);
2730
2731                dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
2732                     i, ceph_mds_state_name(oldstate),
2733                     ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
2734                     ceph_mds_state_name(newstate),
2735                     ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
2736                     session_state_name(s->s_state));
2737
2738                if (i >= newmap->m_max_mds ||
2739                    memcmp(ceph_mdsmap_get_addr(oldmap, i),
2740                           ceph_mdsmap_get_addr(newmap, i),
2741                           sizeof(struct ceph_entity_addr))) {
2742                        if (s->s_state == CEPH_MDS_SESSION_OPENING) {
2743                                /* the session never opened, just close it
2744                                 * out now */
2745                                __wake_requests(mdsc, &s->s_waiting);
2746                                __unregister_session(mdsc, s);
2747                        } else {
2748                                /* just close it */
2749                                mutex_unlock(&mdsc->mutex);
2750                                mutex_lock(&s->s_mutex);
2751                                mutex_lock(&mdsc->mutex);
2752                                ceph_con_close(&s->s_con);
2753                                mutex_unlock(&s->s_mutex);
2754                                s->s_state = CEPH_MDS_SESSION_RESTARTING;
2755                        }
2756
2757                        /* kick any requests waiting on the recovering mds */
2758                        kick_requests(mdsc, i);
2759                } else if (oldstate == newstate) {
2760                        continue;  /* nothing new with this mds */
2761                }
2762
2763                /*
2764                 * send reconnect?
2765                 */
2766                if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
2767                    newstate >= CEPH_MDS_STATE_RECONNECT) {
2768                        mutex_unlock(&mdsc->mutex);
2769                        send_mds_reconnect(mdsc, s);
2770                        mutex_lock(&mdsc->mutex);
2771                }
2772
2773                /*
2774                 * kick request on any mds that has gone active.
2775                 */
2776                if (oldstate < CEPH_MDS_STATE_ACTIVE &&
2777                    newstate >= CEPH_MDS_STATE_ACTIVE) {
2778                        if (oldstate != CEPH_MDS_STATE_CREATING &&
2779                            oldstate != CEPH_MDS_STATE_STARTING)
2780                                pr_info("mds%d recovery completed\n", s->s_mds);
2781                        kick_requests(mdsc, i);
2782                        ceph_kick_flushing_caps(mdsc, s);
2783                        wake_up_session_caps(s, 1);
2784                }
2785        }
2786
2787        for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
2788                s = mdsc->sessions[i];
2789                if (!s)
2790                        continue;
2791                if (!ceph_mdsmap_is_laggy(newmap, i))
2792                        continue;
2793                if (s->s_state == CEPH_MDS_SESSION_OPEN ||
2794                    s->s_state == CEPH_MDS_SESSION_HUNG ||
2795                    s->s_state == CEPH_MDS_SESSION_CLOSING) {
2796                        dout(" connecting to export targets of laggy mds%d\n",
2797                             i);
2798                        __open_export_target_sessions(mdsc, s);
2799                }
2800        }
2801}
2802
2803
2804
2805/*
2806 * leases
2807 */
2808
2809/*
2810 * caller must hold session s_mutex, dentry->d_lock
2811 */
2812void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
2813{
2814        struct ceph_dentry_info *di = ceph_dentry(dentry);
2815
2816        ceph_put_mds_session(di->lease_session);
2817        di->lease_session = NULL;
2818}
2819
2820static void handle_lease(struct ceph_mds_client *mdsc,
2821                         struct ceph_mds_session *session,
2822                         struct ceph_msg *msg)
2823{
2824        struct super_block *sb = mdsc->fsc->sb;
2825        struct inode *inode;
2826        struct dentry *parent, *dentry;
2827        struct ceph_dentry_info *di;
2828        int mds = session->s_mds;
2829        struct ceph_mds_lease *h = msg->front.iov_base;
2830        u32 seq;
2831        struct ceph_vino vino;
2832        struct qstr dname;
2833        int release = 0;
2834
2835        dout("handle_lease from mds%d\n", mds);
2836
2837        /* decode */
2838        if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
2839                goto bad;
2840        vino.ino = le64_to_cpu(h->ino);
2841        vino.snap = CEPH_NOSNAP;
2842        seq = le32_to_cpu(h->seq);
2843        dname.name = (void *)h + sizeof(*h) + sizeof(u32);
2844        dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
2845        if (dname.len != get_unaligned_le32(h+1))
2846                goto bad;
2847
2848        mutex_lock(&session->s_mutex);
2849        session->s_seq++;
2850
2851        /* lookup inode */
2852        inode = ceph_find_inode(sb, vino);
2853        dout("handle_lease %s, ino %llx %p %.*s\n",
2854             ceph_lease_op_name(h->action), vino.ino, inode,
2855             dname.len, dname.name);
2856        if (inode == NULL) {
2857                dout("handle_lease no inode %llx\n", vino.ino);
2858                goto release;
2859        }
2860
2861        /* dentry */
2862        parent = d_find_alias(inode);
2863        if (!parent) {
2864                dout("no parent dentry on inode %p\n", inode);
2865                WARN_ON(1);
2866                goto release;  /* hrm... */
2867        }
2868        dname.hash = full_name_hash(dname.name, dname.len);
2869        dentry = d_lookup(parent, &dname);
2870        dput(parent);
2871        if (!dentry)
2872                goto release;
2873
2874        spin_lock(&dentry->d_lock);
2875        di = ceph_dentry(dentry);
2876        switch (h->action) {
2877        case CEPH_MDS_LEASE_REVOKE:
2878                if (di->lease_session == session) {
2879                        if (ceph_seq_cmp(di->lease_seq, seq) > 0)
2880                                h->seq = cpu_to_le32(di->lease_seq);
2881                        __ceph_mdsc_drop_dentry_lease(dentry);
2882                }
2883                release = 1;
2884                break;
2885
2886        case CEPH_MDS_LEASE_RENEW:
2887                if (di->lease_session == session &&
2888                    di->lease_gen == session->s_cap_gen &&
2889                    di->lease_renew_from &&
2890                    di->lease_renew_after == 0) {
2891                        unsigned long duration =
2892                                le32_to_cpu(h->duration_ms) * HZ / 1000;
2893
2894                        di->lease_seq = seq;
2895                        dentry->d_time = di->lease_renew_from + duration;
2896                        di->lease_renew_after = di->lease_renew_from +
2897                                (duration >> 1);
2898                        di->lease_renew_from = 0;
2899                }
2900                break;
2901        }
2902        spin_unlock(&dentry->d_lock);
2903        dput(dentry);
2904
2905        if (!release)
2906                goto out;
2907
2908release:
2909        /* let's just reuse the same message */
2910        h->action = CEPH_MDS_LEASE_REVOKE_ACK;
2911        ceph_msg_get(msg);
2912        ceph_con_send(&session->s_con, msg);
2913
2914out:
2915        iput(inode);
2916        mutex_unlock(&session->s_mutex);
2917        return;
2918
2919bad:
2920        pr_err("corrupt lease message\n");
2921        ceph_msg_dump(msg);
2922}
2923
2924void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
2925                              struct inode *inode,
2926                              struct dentry *dentry, char action,
2927                              u32 seq)
2928{
2929        struct ceph_msg *msg;
2930        struct ceph_mds_lease *lease;
2931        int len = sizeof(*lease) + sizeof(u32);
2932        int dnamelen = 0;
2933
2934        dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
2935             inode, dentry, ceph_lease_op_name(action), session->s_mds);
2936        dnamelen = dentry->d_name.len;
2937        len += dnamelen;
2938
2939        msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
2940        if (!msg)
2941                return;
2942        lease = msg->front.iov_base;
2943        lease->action = action;
2944        lease->ino = cpu_to_le64(ceph_vino(inode).ino);
2945        lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
2946        lease->seq = cpu_to_le32(seq);
2947        put_unaligned_le32(dnamelen, lease + 1);
2948        memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
2949
2950        /*
2951         * if this is a preemptive lease RELEASE, no need to
2952         * flush request stream, since the actual request will
2953         * soon follow.
2954         */
2955        msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
2956
2957        ceph_con_send(&session->s_con, msg);
2958}
2959
2960/*
2961 * Preemptively release a lease we expect to invalidate anyway.
2962 * Pass @inode always, @dentry is optional.
2963 */
2964void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
2965                             struct dentry *dentry)
2966{
2967        struct ceph_dentry_info *di;
2968        struct ceph_mds_session *session;
2969        u32 seq;
2970
2971        BUG_ON(inode == NULL);
2972        BUG_ON(dentry == NULL);
2973
2974        /* is dentry lease valid? */
2975        spin_lock(&dentry->d_lock);
2976        di = ceph_dentry(dentry);
2977        if (!di || !di->lease_session ||
2978            di->lease_session->s_mds < 0 ||
2979            di->lease_gen != di->lease_session->s_cap_gen ||
2980            !time_before(jiffies, dentry->d_time)) {
2981                dout("lease_release inode %p dentry %p -- "
2982                     "no lease\n",
2983                     inode, dentry);
2984                spin_unlock(&dentry->d_lock);
2985                return;
2986        }
2987
2988        /* we do have a lease on this dentry; note mds and seq */
2989        session = ceph_get_mds_session(di->lease_session);
2990        seq = di->lease_seq;
2991        __ceph_mdsc_drop_dentry_lease(dentry);
2992        spin_unlock(&dentry->d_lock);
2993
2994        dout("lease_release inode %p dentry %p to mds%d\n",
2995             inode, dentry, session->s_mds);
2996        ceph_mdsc_lease_send_msg(session, inode, dentry,
2997                                 CEPH_MDS_LEASE_RELEASE, seq);
2998        ceph_put_mds_session(session);
2999}
3000
3001/*
3002 * drop all leases (and dentry refs) in preparation for umount
3003 */
3004static void drop_leases(struct ceph_mds_client *mdsc)
3005{
3006        int i;
3007
3008        dout("drop_leases\n");
3009        mutex_lock(&mdsc->mutex);
3010        for (i = 0; i < mdsc->max_sessions; i++) {
3011                struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3012                if (!s)
3013                        continue;
3014                mutex_unlock(&mdsc->mutex);
3015                mutex_lock(&s->s_mutex);
3016                mutex_unlock(&s->s_mutex);
3017                ceph_put_mds_session(s);
3018                mutex_lock(&mdsc->mutex);
3019        }
3020        mutex_unlock(&mdsc->mutex);
3021}
3022
3023
3024
3025/*
3026 * delayed work -- periodically trim expired leases, renew caps with mds
3027 */
3028static void schedule_delayed(struct ceph_mds_client *mdsc)
3029{
3030        int delay = 5;
3031        unsigned hz = round_jiffies_relative(HZ * delay);
3032        schedule_delayed_work(&mdsc->delayed_work, hz);
3033}
3034
3035static void delayed_work(struct work_struct *work)
3036{
3037        int i;
3038        struct ceph_mds_client *mdsc =
3039                container_of(work, struct ceph_mds_client, delayed_work.work);
3040        int renew_interval;
3041        int renew_caps;
3042
3043        dout("mdsc delayed_work\n");
3044        ceph_check_delayed_caps(mdsc);
3045
3046        mutex_lock(&mdsc->mutex);
3047        renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
3048        renew_caps = time_after_eq(jiffies, HZ*renew_interval +
3049                                   mdsc->last_renew_caps);
3050        if (renew_caps)
3051                mdsc->last_renew_caps = jiffies;
3052
3053        for (i = 0; i < mdsc->max_sessions; i++) {
3054                struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
3055                if (s == NULL)
3056                        continue;
3057                if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
3058                        dout("resending session close request for mds%d\n",
3059                             s->s_mds);
3060                        request_close_session(mdsc, s);
3061                        ceph_put_mds_session(s);
3062                        continue;
3063                }
3064                if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3065                        if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3066                                s->s_state = CEPH_MDS_SESSION_HUNG;
3067                                pr_info("mds%d hung\n", s->s_mds);
3068                        }
3069                }
3070                if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3071                        /* this mds is failed or recovering, just wait */
3072                        ceph_put_mds_session(s);
3073                        continue;
3074                }
3075                mutex_unlock(&mdsc->mutex);
3076
3077                mutex_lock(&s->s_mutex);
3078                if (renew_caps)
3079                        send_renew_caps(mdsc, s);
3080                else
3081                        ceph_con_keepalive(&s->s_con);
3082                ceph_add_cap_releases(mdsc, s);
3083                if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3084                    s->s_state == CEPH_MDS_SESSION_HUNG)
3085                        ceph_send_cap_releases(mdsc, s);
3086                mutex_unlock(&s->s_mutex);
3087                ceph_put_mds_session(s);
3088
3089                mutex_lock(&mdsc->mutex);
3090        }
3091        mutex_unlock(&mdsc->mutex);
3092
3093        schedule_delayed(mdsc);
3094}
3095
3096int ceph_mdsc_init(struct ceph_fs_client *fsc)
3097
3098{
3099        struct ceph_mds_client *mdsc;
3100
3101        mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3102        if (!mdsc)
3103                return -ENOMEM;
3104        mdsc->fsc = fsc;
3105        fsc->mdsc = mdsc;
3106        mutex_init(&mdsc->mutex);
3107        mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3108        if (mdsc->mdsmap == NULL) {
3109                kfree(mdsc);
3110                return -ENOMEM;
3111        }
3112
3113        init_completion(&mdsc->safe_umount_waiters);
3114        init_waitqueue_head(&mdsc->session_close_wq);
3115        INIT_LIST_HEAD(&mdsc->waiting_for_map);
3116        mdsc->sessions = NULL;
3117        mdsc->max_sessions = 0;
3118        mdsc->stopping = 0;
3119        init_rwsem(&mdsc->snap_rwsem);
3120        mdsc->snap_realms = RB_ROOT;
3121        INIT_LIST_HEAD(&mdsc->snap_empty);
3122        spin_lock_init(&mdsc->snap_empty_lock);
3123        mdsc->last_tid = 0;
3124        mdsc->request_tree = RB_ROOT;
3125        INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3126        mdsc->last_renew_caps = jiffies;
3127        INIT_LIST_HEAD(&mdsc->cap_delay_list);
3128        spin_lock_init(&mdsc->cap_delay_lock);
3129        INIT_LIST_HEAD(&mdsc->snap_flush_list);
3130        spin_lock_init(&mdsc->snap_flush_lock);
3131        mdsc->cap_flush_seq = 0;
3132        INIT_LIST_HEAD(&mdsc->cap_dirty);
3133        INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3134        mdsc->num_cap_flushing = 0;
3135        spin_lock_init(&mdsc->cap_dirty_lock);
3136        init_waitqueue_head(&mdsc->cap_flushing_wq);
3137        spin_lock_init(&mdsc->dentry_lru_lock);
3138        INIT_LIST_HEAD(&mdsc->dentry_lru);
3139
3140        ceph_caps_init(mdsc);
3141        ceph_adjust_min_caps(mdsc, fsc->min_caps);
3142
3143        return 0;
3144}
3145
3146/*
3147 * Wait for safe replies on open mds requests.  If we time out, drop
3148 * all requests from the tree to avoid dangling dentry refs.
3149 */
3150static void wait_requests(struct ceph_mds_client *mdsc)
3151{
3152        struct ceph_mds_request *req;
3153        struct ceph_fs_client *fsc = mdsc->fsc;
3154
3155        mutex_lock(&mdsc->mutex);
3156        if (__get_oldest_req(mdsc)) {
3157                mutex_unlock(&mdsc->mutex);
3158
3159                dout("wait_requests waiting for requests\n");
3160                wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3161                                    fsc->client->options->mount_timeout * HZ);
3162
3163                /* tear down remaining requests */
3164                mutex_lock(&mdsc->mutex);
3165                while ((req = __get_oldest_req(mdsc))) {
3166                        dout("wait_requests timed out on tid %llu\n",
3167                             req->r_tid);
3168                        __unregister_request(mdsc, req);
3169                }
3170        }
3171        mutex_unlock(&mdsc->mutex);
3172        dout("wait_requests done\n");
3173}
3174
3175/*
3176 * called before mount is ro, and before dentries are torn down.
3177 * (hmm, does this still race with new lookups?)
3178 */
3179void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3180{
3181        dout("pre_umount\n");
3182        mdsc->stopping = 1;
3183
3184        drop_leases(mdsc);
3185        ceph_flush_dirty_caps(mdsc);
3186        wait_requests(mdsc);
3187
3188        /*
3189         * wait for reply handlers to drop their request refs and
3190         * their inode/dcache refs
3191         */
3192        ceph_msgr_flush();
3193}
3194
3195/*
3196 * wait for all write mds requests to flush.
3197 */
3198static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3199{
3200        struct ceph_mds_request *req = NULL, *nextreq;
3201        struct rb_node *n;
3202
3203        mutex_lock(&mdsc->mutex);
3204        dout("wait_unsafe_requests want %lld\n", want_tid);
3205restart:
3206        req = __get_oldest_req(mdsc);
3207        while (req && req->r_tid <= want_tid) {
3208                /* find next request */
3209                n = rb_next(&req->r_node);
3210                if (n)
3211                        nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3212                else
3213                        nextreq = NULL;
3214                if ((req->r_op & CEPH_MDS_OP_WRITE)) {
3215                        /* write op */
3216                        ceph_mdsc_get_request(req);
3217                        if (nextreq)
3218                                ceph_mdsc_get_request(nextreq);
3219                        mutex_unlock(&mdsc->mutex);
3220                        dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3221                             req->r_tid, want_tid);
3222                        wait_for_completion(&req->r_safe_completion);
3223                        mutex_lock(&mdsc->mutex);
3224                        ceph_mdsc_put_request(req);
3225                        if (!nextreq)
3226                                break;  /* next dne before, so we're done! */
3227                        if (RB_EMPTY_NODE(&nextreq->r_node)) {
3228                                /* next request was removed from tree */
3229                                ceph_mdsc_put_request(nextreq);
3230                                goto restart;
3231                        }
3232                        ceph_mdsc_put_request(nextreq);  /* won't go away */
3233                }
3234                req = nextreq;
3235        }
3236        mutex_unlock(&mdsc->mutex);
3237        dout("wait_unsafe_requests done\n");
3238}
3239
3240void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3241{
3242        u64 want_tid, want_flush;
3243
3244        if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3245                return;
3246
3247        dout("sync\n");
3248        mutex_lock(&mdsc->mutex);
3249        want_tid = mdsc->last_tid;
3250        want_flush = mdsc->cap_flush_seq;
3251        mutex_unlock(&mdsc->mutex);
3252        dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush);
3253
3254        ceph_flush_dirty_caps(mdsc);
3255
3256        wait_unsafe_requests(mdsc, want_tid);
3257        wait_event(mdsc->cap_flushing_wq, check_cap_flush(mdsc, want_flush));
3258}
3259
3260/*
3261 * true if all sessions are closed, or we force unmount
3262 */
3263static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3264{
3265        int i, n = 0;
3266
3267        if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3268                return true;
3269
3270        mutex_lock(&mdsc->mutex);
3271        for (i = 0; i < mdsc->max_sessions; i++)
3272                if (mdsc->sessions[i])
3273                        n++;
3274        mutex_unlock(&mdsc->mutex);
3275        return n == 0;
3276}
3277
3278/*
3279 * called after sb is ro.
3280 */
3281void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3282{
3283        struct ceph_mds_session *session;
3284        int i;
3285        struct ceph_fs_client *fsc = mdsc->fsc;
3286        unsigned long timeout = fsc->client->options->mount_timeout * HZ;
3287
3288        dout("close_sessions\n");
3289
3290        /* close sessions */
3291        mutex_lock(&mdsc->mutex);
3292        for (i = 0; i < mdsc->max_sessions; i++) {
3293                session = __ceph_lookup_mds_session(mdsc, i);
3294                if (!session)
3295                        continue;
3296                mutex_unlock(&mdsc->mutex);
3297                mutex_lock(&session->s_mutex);
3298                __close_session(mdsc, session);
3299                mutex_unlock(&session->s_mutex);
3300                ceph_put_mds_session(session);
3301                mutex_lock(&mdsc->mutex);
3302        }
3303        mutex_unlock(&mdsc->mutex);
3304
3305        dout("waiting for sessions to close\n");
3306        wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3307                           timeout);
3308
3309        /* tear down remaining sessions */
3310        mutex_lock(&mdsc->mutex);
3311        for (i = 0; i < mdsc->max_sessions; i++) {
3312                if (mdsc->sessions[i]) {
3313                        session = get_session(mdsc->sessions[i]);
3314                        __unregister_session(mdsc, session);
3315                        mutex_unlock(&mdsc->mutex);
3316                        mutex_lock(&session->s_mutex);
3317                        remove_session_caps(session);
3318                        mutex_unlock(&session->s_mutex);
3319                        ceph_put_mds_session(session);
3320                        mutex_lock(&mdsc->mutex);
3321                }
3322        }
3323        WARN_ON(!list_empty(&mdsc->cap_delay_list));
3324        mutex_unlock(&mdsc->mutex);
3325
3326        ceph_cleanup_empty_realms(mdsc);
3327
3328        cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3329
3330        dout("stopped\n");
3331}
3332
3333static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3334{
3335        dout("stop\n");
3336        cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3337        if (mdsc->mdsmap)
3338                ceph_mdsmap_destroy(mdsc->mdsmap);
3339        kfree(mdsc->sessions);
3340        ceph_caps_finalize(mdsc);
3341}
3342
3343void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3344{
3345        struct ceph_mds_client *mdsc = fsc->mdsc;
3346
3347        dout("mdsc_destroy %p\n", mdsc);
3348        ceph_mdsc_stop(mdsc);
3349
3350        /* flush out any connection work with references to us */
3351        ceph_msgr_flush();
3352
3353        fsc->mdsc = NULL;
3354        kfree(mdsc);
3355        dout("mdsc_destroy %p done\n", mdsc);
3356}
3357
3358
3359/*
3360 * handle mds map update.
3361 */
3362void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3363{
3364        u32 epoch;
3365        u32 maplen;
3366        void *p = msg->front.iov_base;
3367        void *end = p + msg->front.iov_len;
3368        struct ceph_mdsmap *newmap, *oldmap;
3369        struct ceph_fsid fsid;
3370        int err = -EINVAL;
3371
3372        ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3373        ceph_decode_copy(&p, &fsid, sizeof(fsid));
3374        if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3375                return;
3376        epoch = ceph_decode_32(&p);
3377        maplen = ceph_decode_32(&p);
3378        dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3379
3380        /* do we need it? */
3381        ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
3382        mutex_lock(&mdsc->mutex);
3383        if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3384                dout("handle_map epoch %u <= our %u\n",
3385                     epoch, mdsc->mdsmap->m_epoch);
3386                mutex_unlock(&mdsc->mutex);
3387                return;
3388        }
3389
3390        newmap = ceph_mdsmap_decode(&p, end);
3391        if (IS_ERR(newmap)) {
3392                err = PTR_ERR(newmap);
3393                goto bad_unlock;
3394        }
3395
3396        /* swap into place */
3397        if (mdsc->mdsmap) {
3398                oldmap = mdsc->mdsmap;
3399                mdsc->mdsmap = newmap;
3400                check_new_map(mdsc, newmap, oldmap);
3401                ceph_mdsmap_destroy(oldmap);
3402        } else {
3403                mdsc->mdsmap = newmap;  /* first mds map */
3404        }
3405        mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3406
3407        __wake_requests(mdsc, &mdsc->waiting_for_map);
3408
3409        mutex_unlock(&mdsc->mutex);
3410        schedule_delayed(mdsc);
3411        return;
3412
3413bad_unlock:
3414        mutex_unlock(&mdsc->mutex);
3415bad:
3416        pr_err("error decoding mdsmap %d\n", err);
3417        return;
3418}
3419
3420static struct ceph_connection *con_get(struct ceph_connection *con)
3421{
3422        struct ceph_mds_session *s = con->private;
3423
3424        if (get_session(s)) {
3425                dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3426                return con;
3427        }
3428        dout("mdsc con_get %p FAIL\n", s);
3429        return NULL;
3430}
3431
3432static void con_put(struct ceph_connection *con)
3433{
3434        struct ceph_mds_session *s = con->private;
3435
3436        dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3437        ceph_put_mds_session(s);
3438}
3439
3440/*
3441 * if the client is unresponsive for long enough, the mds will kill
3442 * the session entirely.
3443 */
3444static void peer_reset(struct ceph_connection *con)
3445{
3446        struct ceph_mds_session *s = con->private;
3447        struct ceph_mds_client *mdsc = s->s_mdsc;
3448
3449        pr_warning("mds%d closed our session\n", s->s_mds);
3450        send_mds_reconnect(mdsc, s);
3451}
3452
3453static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3454{
3455        struct ceph_mds_session *s = con->private;
3456        struct ceph_mds_client *mdsc = s->s_mdsc;
3457        int type = le16_to_cpu(msg->hdr.type);
3458
3459        mutex_lock(&mdsc->mutex);
3460        if (__verify_registered_session(mdsc, s) < 0) {
3461                mutex_unlock(&mdsc->mutex);
3462                goto out;
3463        }
3464        mutex_unlock(&mdsc->mutex);
3465
3466        switch (type) {
3467        case CEPH_MSG_MDS_MAP:
3468                ceph_mdsc_handle_map(mdsc, msg);
3469                break;
3470        case CEPH_MSG_CLIENT_SESSION:
3471                handle_session(s, msg);
3472                break;
3473        case CEPH_MSG_CLIENT_REPLY:
3474                handle_reply(s, msg);
3475                break;
3476        case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3477                handle_forward(mdsc, s, msg);
3478                break;
3479        case CEPH_MSG_CLIENT_CAPS:
3480                ceph_handle_caps(s, msg);
3481                break;
3482        case CEPH_MSG_CLIENT_SNAP:
3483                ceph_handle_snap(mdsc, s, msg);
3484                break;
3485        case CEPH_MSG_CLIENT_LEASE:
3486                handle_lease(mdsc, s, msg);
3487                break;
3488
3489        default:
3490                pr_err("received unknown message type %d %s\n", type,
3491                       ceph_msg_type_name(type));
3492        }
3493out:
3494        ceph_msg_put(msg);
3495}
3496
3497/*
3498 * authentication
3499 */
3500
3501/*
3502 * Note: returned pointer is the address of a structure that's
3503 * managed separately.  Caller must *not* attempt to free it.
3504 */
3505static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3506                                        int *proto, int force_new)
3507{
3508        struct ceph_mds_session *s = con->private;
3509        struct ceph_mds_client *mdsc = s->s_mdsc;
3510        struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3511        struct ceph_auth_handshake *auth = &s->s_auth;
3512
3513        if (force_new && auth->authorizer) {
3514                ceph_auth_destroy_authorizer(ac, auth->authorizer);
3515                auth->authorizer = NULL;
3516        }
3517        if (!auth->authorizer) {
3518                int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3519                                                      auth);
3520                if (ret)
3521                        return ERR_PTR(ret);
3522        } else {
3523                int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3524                                                      auth);
3525                if (ret)
3526                        return ERR_PTR(ret);
3527        }
3528        *proto = ac->protocol;
3529
3530        return auth;
3531}
3532
3533
3534static int verify_authorizer_reply(struct ceph_connection *con, int len)
3535{
3536        struct ceph_mds_session *s = con->private;
3537        struct ceph_mds_client *mdsc = s->s_mdsc;
3538        struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3539
3540        return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3541}
3542
3543static int invalidate_authorizer(struct ceph_connection *con)
3544{
3545        struct ceph_mds_session *s = con->private;
3546        struct ceph_mds_client *mdsc = s->s_mdsc;
3547        struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3548
3549        ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3550
3551        return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3552}
3553
3554static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3555                                struct ceph_msg_header *hdr, int *skip)
3556{
3557        struct ceph_msg *msg;
3558        int type = (int) le16_to_cpu(hdr->type);
3559        int front_len = (int) le32_to_cpu(hdr->front_len);
3560
3561        if (con->in_msg)
3562                return con->in_msg;
3563
3564        *skip = 0;
3565        msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3566        if (!msg) {
3567                pr_err("unable to allocate msg type %d len %d\n",
3568                       type, front_len);
3569                return NULL;
3570        }
3571
3572        return msg;
3573}
3574
3575static const struct ceph_connection_operations mds_con_ops = {
3576        .get = con_get,
3577        .put = con_put,
3578        .dispatch = dispatch,
3579        .get_authorizer = get_authorizer,
3580        .verify_authorizer_reply = verify_authorizer_reply,
3581        .invalidate_authorizer = invalidate_authorizer,
3582        .peer_reset = peer_reset,
3583        .alloc_msg = mds_alloc_msg,
3584};
3585
3586/* eof */
3587