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  42 * are no longer valid.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