linux/fs/nfsd/nfssvc.c
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   1/*
   2 * Central processing for nfsd.
   3 *
   4 * Authors:     Olaf Kirch (okir@monad.swb.de)
   5 *
   6 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
   7 */
   8
   9#include <linux/sched.h>
  10#include <linux/freezer.h>
  11#include <linux/module.h>
  12#include <linux/fs_struct.h>
  13#include <linux/swap.h>
  14
  15#include <linux/sunrpc/stats.h>
  16#include <linux/sunrpc/svcsock.h>
  17#include <linux/lockd/bind.h>
  18#include <linux/nfsacl.h>
  19#include <linux/seq_file.h>
  20#include <net/net_namespace.h>
  21#include "nfsd.h"
  22#include "cache.h"
  23#include "vfs.h"
  24#include "netns.h"
  25
  26#define NFSDDBG_FACILITY        NFSDDBG_SVC
  27
  28extern struct svc_program       nfsd_program;
  29static int                      nfsd(void *vrqstp);
  30
  31/*
  32 * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members
  33 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
  34 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
  35 *
  36 * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a
  37 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
  38 * of nfsd threads must exist and each must listed in ->sp_all_threads in each
  39 * entry of ->sv_pools[].
  40 *
  41 * Transitions of the thread count between zero and non-zero are of particular
  42 * interest since the svc_serv needs to be created and initialized at that
  43 * point, or freed.
  44 *
  45 * Finally, the nfsd_mutex also protects some of the global variables that are
  46 * accessed when nfsd starts and that are settable via the write_* routines in
  47 * nfsctl.c. In particular:
  48 *
  49 *      user_recovery_dirname
  50 *      user_lease_time
  51 *      nfsd_versions
  52 */
  53DEFINE_MUTEX(nfsd_mutex);
  54
  55/*
  56 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
  57 * nfsd_drc_max_pages limits the total amount of memory available for
  58 * version 4.1 DRC caches.
  59 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
  60 */
  61spinlock_t      nfsd_drc_lock;
  62unsigned long   nfsd_drc_max_mem;
  63unsigned long   nfsd_drc_mem_used;
  64
  65#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
  66static struct svc_stat  nfsd_acl_svcstats;
  67static struct svc_version *     nfsd_acl_version[] = {
  68        [2] = &nfsd_acl_version2,
  69        [3] = &nfsd_acl_version3,
  70};
  71
  72#define NFSD_ACL_MINVERS            2
  73#define NFSD_ACL_NRVERS         ARRAY_SIZE(nfsd_acl_version)
  74static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
  75
  76static struct svc_program       nfsd_acl_program = {
  77        .pg_prog                = NFS_ACL_PROGRAM,
  78        .pg_nvers               = NFSD_ACL_NRVERS,
  79        .pg_vers                = nfsd_acl_versions,
  80        .pg_name                = "nfsacl",
  81        .pg_class               = "nfsd",
  82        .pg_stats               = &nfsd_acl_svcstats,
  83        .pg_authenticate        = &svc_set_client,
  84};
  85
  86static struct svc_stat  nfsd_acl_svcstats = {
  87        .program        = &nfsd_acl_program,
  88};
  89#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
  90
  91static struct svc_version *     nfsd_version[] = {
  92        [2] = &nfsd_version2,
  93#if defined(CONFIG_NFSD_V3)
  94        [3] = &nfsd_version3,
  95#endif
  96#if defined(CONFIG_NFSD_V4)
  97        [4] = &nfsd_version4,
  98#endif
  99};
 100
 101#define NFSD_MINVERS            2
 102#define NFSD_NRVERS             ARRAY_SIZE(nfsd_version)
 103static struct svc_version *nfsd_versions[NFSD_NRVERS];
 104
 105struct svc_program              nfsd_program = {
 106#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
 107        .pg_next                = &nfsd_acl_program,
 108#endif
 109        .pg_prog                = NFS_PROGRAM,          /* program number */
 110        .pg_nvers               = NFSD_NRVERS,          /* nr of entries in nfsd_version */
 111        .pg_vers                = nfsd_versions,        /* version table */
 112        .pg_name                = "nfsd",               /* program name */
 113        .pg_class               = "nfsd",               /* authentication class */
 114        .pg_stats               = &nfsd_svcstats,       /* version table */
 115        .pg_authenticate        = &svc_set_client,      /* export authentication */
 116
 117};
 118
 119static bool nfsd_supported_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1] = {
 120        [0] = 1,
 121        [1] = 1,
 122};
 123
 124int nfsd_vers(int vers, enum vers_op change)
 125{
 126        if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
 127                return 0;
 128        switch(change) {
 129        case NFSD_SET:
 130                nfsd_versions[vers] = nfsd_version[vers];
 131#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
 132                if (vers < NFSD_ACL_NRVERS)
 133                        nfsd_acl_versions[vers] = nfsd_acl_version[vers];
 134#endif
 135                break;
 136        case NFSD_CLEAR:
 137                nfsd_versions[vers] = NULL;
 138#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
 139                if (vers < NFSD_ACL_NRVERS)
 140                        nfsd_acl_versions[vers] = NULL;
 141#endif
 142                break;
 143        case NFSD_TEST:
 144                return nfsd_versions[vers] != NULL;
 145        case NFSD_AVAIL:
 146                return nfsd_version[vers] != NULL;
 147        }
 148        return 0;
 149}
 150
 151int nfsd_minorversion(u32 minorversion, enum vers_op change)
 152{
 153        if (minorversion > NFSD_SUPPORTED_MINOR_VERSION)
 154                return -1;
 155        switch(change) {
 156        case NFSD_SET:
 157                nfsd_supported_minorversions[minorversion] = true;
 158                break;
 159        case NFSD_CLEAR:
 160                nfsd_supported_minorversions[minorversion] = false;
 161                break;
 162        case NFSD_TEST:
 163                return nfsd_supported_minorversions[minorversion];
 164        case NFSD_AVAIL:
 165                return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
 166        }
 167        return 0;
 168}
 169
 170/*
 171 * Maximum number of nfsd processes
 172 */
 173#define NFSD_MAXSERVS           8192
 174
 175int nfsd_nrthreads(struct net *net)
 176{
 177        int rv = 0;
 178        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 179
 180        mutex_lock(&nfsd_mutex);
 181        if (nn->nfsd_serv)
 182                rv = nn->nfsd_serv->sv_nrthreads;
 183        mutex_unlock(&nfsd_mutex);
 184        return rv;
 185}
 186
 187static int nfsd_init_socks(struct net *net)
 188{
 189        int error;
 190        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 191
 192        if (!list_empty(&nn->nfsd_serv->sv_permsocks))
 193                return 0;
 194
 195        error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
 196                                        SVC_SOCK_DEFAULTS);
 197        if (error < 0)
 198                return error;
 199
 200        error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
 201                                        SVC_SOCK_DEFAULTS);
 202        if (error < 0)
 203                return error;
 204
 205        return 0;
 206}
 207
 208static int nfsd_users = 0;
 209
 210static int nfsd_startup_generic(int nrservs)
 211{
 212        int ret;
 213
 214        if (nfsd_users++)
 215                return 0;
 216
 217        /*
 218         * Readahead param cache - will no-op if it already exists.
 219         * (Note therefore results will be suboptimal if number of
 220         * threads is modified after nfsd start.)
 221         */
 222        ret = nfsd_racache_init(2*nrservs);
 223        if (ret)
 224                return ret;
 225        ret = nfs4_state_start();
 226        if (ret)
 227                goto out_racache;
 228        return 0;
 229
 230out_racache:
 231        nfsd_racache_shutdown();
 232        return ret;
 233}
 234
 235static void nfsd_shutdown_generic(void)
 236{
 237        if (--nfsd_users)
 238                return;
 239
 240        nfs4_state_shutdown();
 241        nfsd_racache_shutdown();
 242}
 243
 244static int nfsd_startup_net(int nrservs, struct net *net)
 245{
 246        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 247        int ret;
 248
 249        if (nn->nfsd_net_up)
 250                return 0;
 251
 252        ret = nfsd_startup_generic(nrservs);
 253        if (ret)
 254                return ret;
 255        ret = nfsd_init_socks(net);
 256        if (ret)
 257                goto out_socks;
 258        ret = lockd_up(net);
 259        if (ret)
 260                goto out_socks;
 261        ret = nfs4_state_start_net(net);
 262        if (ret)
 263                goto out_lockd;
 264
 265        nn->nfsd_net_up = true;
 266        return 0;
 267
 268out_lockd:
 269        lockd_down(net);
 270out_socks:
 271        nfsd_shutdown_generic();
 272        return ret;
 273}
 274
 275static void nfsd_shutdown_net(struct net *net)
 276{
 277        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 278
 279        nfs4_state_shutdown_net(net);
 280        lockd_down(net);
 281        nn->nfsd_net_up = false;
 282        nfsd_shutdown_generic();
 283}
 284
 285static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
 286{
 287        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 288
 289        /*
 290         * write_ports can create the server without actually starting
 291         * any threads--if we get shut down before any threads are
 292         * started, then nfsd_last_thread will be run before any of this
 293         * other initialization has been done.
 294         */
 295        if (!nn->nfsd_net_up)
 296                return;
 297        nfsd_shutdown_net(net);
 298
 299        svc_rpcb_cleanup(serv, net);
 300
 301        printk(KERN_WARNING "nfsd: last server has exited, flushing export "
 302                            "cache\n");
 303        nfsd_export_flush(net);
 304}
 305
 306void nfsd_reset_versions(void)
 307{
 308        int found_one = 0;
 309        int i;
 310
 311        for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
 312                if (nfsd_program.pg_vers[i])
 313                        found_one = 1;
 314        }
 315
 316        if (!found_one) {
 317                for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
 318                        nfsd_program.pg_vers[i] = nfsd_version[i];
 319#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
 320                for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
 321                        nfsd_acl_program.pg_vers[i] =
 322                                nfsd_acl_version[i];
 323#endif
 324        }
 325}
 326
 327/*
 328 * Each session guarantees a negotiated per slot memory cache for replies
 329 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
 330 * NFSv4.1 server might want to use more memory for a DRC than a machine
 331 * with mutiple services.
 332 *
 333 * Impose a hard limit on the number of pages for the DRC which varies
 334 * according to the machines free pages. This is of course only a default.
 335 *
 336 * For now this is a #defined shift which could be under admin control
 337 * in the future.
 338 */
 339static void set_max_drc(void)
 340{
 341        #define NFSD_DRC_SIZE_SHIFT     10
 342        nfsd_drc_max_mem = (nr_free_buffer_pages()
 343                                        >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
 344        nfsd_drc_mem_used = 0;
 345        spin_lock_init(&nfsd_drc_lock);
 346        dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
 347}
 348
 349static int nfsd_get_default_max_blksize(void)
 350{
 351        struct sysinfo i;
 352        unsigned long long target;
 353        unsigned long ret;
 354
 355        si_meminfo(&i);
 356        target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
 357        /*
 358         * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
 359         * machines, but only uses 32K on 128M machines.  Bottom out at
 360         * 8K on 32M and smaller.  Of course, this is only a default.
 361         */
 362        target >>= 12;
 363
 364        ret = NFSSVC_MAXBLKSIZE;
 365        while (ret > target && ret >= 8*1024*2)
 366                ret /= 2;
 367        return ret;
 368}
 369
 370int nfsd_create_serv(struct net *net)
 371{
 372        int error;
 373        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 374
 375        WARN_ON(!mutex_is_locked(&nfsd_mutex));
 376        if (nn->nfsd_serv) {
 377                svc_get(nn->nfsd_serv);
 378                return 0;
 379        }
 380        if (nfsd_max_blksize == 0)
 381                nfsd_max_blksize = nfsd_get_default_max_blksize();
 382        nfsd_reset_versions();
 383        nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
 384                                      nfsd_last_thread, nfsd, THIS_MODULE);
 385        if (nn->nfsd_serv == NULL)
 386                return -ENOMEM;
 387
 388        error = svc_bind(nn->nfsd_serv, net);
 389        if (error < 0) {
 390                svc_destroy(nn->nfsd_serv);
 391                return error;
 392        }
 393
 394        set_max_drc();
 395        do_gettimeofday(&nn->nfssvc_boot);              /* record boot time */
 396        return 0;
 397}
 398
 399int nfsd_nrpools(struct net *net)
 400{
 401        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 402
 403        if (nn->nfsd_serv == NULL)
 404                return 0;
 405        else
 406                return nn->nfsd_serv->sv_nrpools;
 407}
 408
 409int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
 410{
 411        int i = 0;
 412        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 413
 414        if (nn->nfsd_serv != NULL) {
 415                for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
 416                        nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
 417        }
 418
 419        return 0;
 420}
 421
 422void nfsd_destroy(struct net *net)
 423{
 424        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 425        int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
 426
 427        if (destroy)
 428                svc_shutdown_net(nn->nfsd_serv, net);
 429        svc_destroy(nn->nfsd_serv);
 430        if (destroy)
 431                nn->nfsd_serv = NULL;
 432}
 433
 434int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
 435{
 436        int i = 0;
 437        int tot = 0;
 438        int err = 0;
 439        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 440
 441        WARN_ON(!mutex_is_locked(&nfsd_mutex));
 442
 443        if (nn->nfsd_serv == NULL || n <= 0)
 444                return 0;
 445
 446        if (n > nn->nfsd_serv->sv_nrpools)
 447                n = nn->nfsd_serv->sv_nrpools;
 448
 449        /* enforce a global maximum number of threads */
 450        tot = 0;
 451        for (i = 0; i < n; i++) {
 452                if (nthreads[i] > NFSD_MAXSERVS)
 453                        nthreads[i] = NFSD_MAXSERVS;
 454                tot += nthreads[i];
 455        }
 456        if (tot > NFSD_MAXSERVS) {
 457                /* total too large: scale down requested numbers */
 458                for (i = 0; i < n && tot > 0; i++) {
 459                        int new = nthreads[i] * NFSD_MAXSERVS / tot;
 460                        tot -= (nthreads[i] - new);
 461                        nthreads[i] = new;
 462                }
 463                for (i = 0; i < n && tot > 0; i++) {
 464                        nthreads[i]--;
 465                        tot--;
 466                }
 467        }
 468
 469        /*
 470         * There must always be a thread in pool 0; the admin
 471         * can't shut down NFS completely using pool_threads.
 472         */
 473        if (nthreads[0] == 0)
 474                nthreads[0] = 1;
 475
 476        /* apply the new numbers */
 477        svc_get(nn->nfsd_serv);
 478        for (i = 0; i < n; i++) {
 479                err = svc_set_num_threads(nn->nfsd_serv, &nn->nfsd_serv->sv_pools[i],
 480                                          nthreads[i]);
 481                if (err)
 482                        break;
 483        }
 484        nfsd_destroy(net);
 485        return err;
 486}
 487
 488/*
 489 * Adjust the number of threads and return the new number of threads.
 490 * This is also the function that starts the server if necessary, if
 491 * this is the first time nrservs is nonzero.
 492 */
 493int
 494nfsd_svc(int nrservs, struct net *net)
 495{
 496        int     error;
 497        bool    nfsd_up_before;
 498        struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 499
 500        mutex_lock(&nfsd_mutex);
 501        dprintk("nfsd: creating service\n");
 502        if (nrservs <= 0)
 503                nrservs = 0;
 504        if (nrservs > NFSD_MAXSERVS)
 505                nrservs = NFSD_MAXSERVS;
 506        error = 0;
 507        if (nrservs == 0 && nn->nfsd_serv == NULL)
 508                goto out;
 509
 510        error = nfsd_create_serv(net);
 511        if (error)
 512                goto out;
 513
 514        nfsd_up_before = nn->nfsd_net_up;
 515
 516        error = nfsd_startup_net(nrservs, net);
 517        if (error)
 518                goto out_destroy;
 519        error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs);
 520        if (error)
 521                goto out_shutdown;
 522        /* We are holding a reference to nn->nfsd_serv which
 523         * we don't want to count in the return value,
 524         * so subtract 1
 525         */
 526        error = nn->nfsd_serv->sv_nrthreads - 1;
 527out_shutdown:
 528        if (error < 0 && !nfsd_up_before)
 529                nfsd_shutdown_net(net);
 530out_destroy:
 531        nfsd_destroy(net);              /* Release server */
 532out:
 533        mutex_unlock(&nfsd_mutex);
 534        return error;
 535}
 536
 537
 538/*
 539 * This is the NFS server kernel thread
 540 */
 541static int
 542nfsd(void *vrqstp)
 543{
 544        struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
 545        struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
 546        struct net *net = perm_sock->xpt_net;
 547        int err;
 548
 549        /* Lock module and set up kernel thread */
 550        mutex_lock(&nfsd_mutex);
 551
 552        /* At this point, the thread shares current->fs
 553         * with the init process. We need to create files with a
 554         * umask of 0 instead of init's umask. */
 555        if (unshare_fs_struct() < 0) {
 556                printk("Unable to start nfsd thread: out of memory\n");
 557                goto out;
 558        }
 559
 560        current->fs->umask = 0;
 561
 562        /*
 563         * thread is spawned with all signals set to SIG_IGN, re-enable
 564         * the ones that will bring down the thread
 565         */
 566        allow_signal(SIGKILL);
 567        allow_signal(SIGHUP);
 568        allow_signal(SIGINT);
 569        allow_signal(SIGQUIT);
 570
 571        nfsdstats.th_cnt++;
 572        mutex_unlock(&nfsd_mutex);
 573
 574        /*
 575         * We want less throttling in balance_dirty_pages() so that nfs to
 576         * localhost doesn't cause nfsd to lock up due to all the client's
 577         * dirty pages.
 578         */
 579        current->flags |= PF_LESS_THROTTLE;
 580        set_freezable();
 581
 582        /*
 583         * The main request loop
 584         */
 585        for (;;) {
 586                /*
 587                 * Find a socket with data available and call its
 588                 * recvfrom routine.
 589                 */
 590                while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
 591                        ;
 592                if (err == -EINTR)
 593                        break;
 594                validate_process_creds();
 595                svc_process(rqstp);
 596                validate_process_creds();
 597        }
 598
 599        /* Clear signals before calling svc_exit_thread() */
 600        flush_signals(current);
 601
 602        mutex_lock(&nfsd_mutex);
 603        nfsdstats.th_cnt --;
 604
 605out:
 606        rqstp->rq_server = NULL;
 607
 608        /* Release the thread */
 609        svc_exit_thread(rqstp);
 610
 611        nfsd_destroy(net);
 612
 613        /* Release module */
 614        mutex_unlock(&nfsd_mutex);
 615        module_put_and_exit(0);
 616        return 0;
 617}
 618
 619static __be32 map_new_errors(u32 vers, __be32 nfserr)
 620{
 621        if (nfserr == nfserr_jukebox && vers == 2)
 622                return nfserr_dropit;
 623        if (nfserr == nfserr_wrongsec && vers < 4)
 624                return nfserr_acces;
 625        return nfserr;
 626}
 627
 628int
 629nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
 630{
 631        struct svc_procedure    *proc;
 632        kxdrproc_t              xdr;
 633        __be32                  nfserr;
 634        __be32                  *nfserrp;
 635
 636        dprintk("nfsd_dispatch: vers %d proc %d\n",
 637                                rqstp->rq_vers, rqstp->rq_proc);
 638        proc = rqstp->rq_procinfo;
 639
 640        /*
 641         * Give the xdr decoder a chance to change this if it wants
 642         * (necessary in the NFSv4.0 compound case)
 643         */
 644        rqstp->rq_cachetype = proc->pc_cachetype;
 645        /* Decode arguments */
 646        xdr = proc->pc_decode;
 647        if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
 648                        rqstp->rq_argp)) {
 649                dprintk("nfsd: failed to decode arguments!\n");
 650                *statp = rpc_garbage_args;
 651                return 1;
 652        }
 653
 654        /* Check whether we have this call in the cache. */
 655        switch (nfsd_cache_lookup(rqstp)) {
 656        case RC_DROPIT:
 657                return 0;
 658        case RC_REPLY:
 659                return 1;
 660        case RC_DOIT:;
 661                /* do it */
 662        }
 663
 664        /* need to grab the location to store the status, as
 665         * nfsv4 does some encoding while processing 
 666         */
 667        nfserrp = rqstp->rq_res.head[0].iov_base
 668                + rqstp->rq_res.head[0].iov_len;
 669        rqstp->rq_res.head[0].iov_len += sizeof(__be32);
 670
 671        /* Now call the procedure handler, and encode NFS status. */
 672        nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
 673        nfserr = map_new_errors(rqstp->rq_vers, nfserr);
 674        if (nfserr == nfserr_dropit || rqstp->rq_dropme) {
 675                dprintk("nfsd: Dropping request; may be revisited later\n");
 676                nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
 677                return 0;
 678        }
 679
 680        if (rqstp->rq_proc != 0)
 681                *nfserrp++ = nfserr;
 682
 683        /* Encode result.
 684         * For NFSv2, additional info is never returned in case of an error.
 685         */
 686        if (!(nfserr && rqstp->rq_vers == 2)) {
 687                xdr = proc->pc_encode;
 688                if (xdr && !xdr(rqstp, nfserrp,
 689                                rqstp->rq_resp)) {
 690                        /* Failed to encode result. Release cache entry */
 691                        dprintk("nfsd: failed to encode result!\n");
 692                        nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
 693                        *statp = rpc_system_err;
 694                        return 1;
 695                }
 696        }
 697
 698        /* Store reply in cache. */
 699        nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
 700        return 1;
 701}
 702
 703int nfsd_pool_stats_open(struct inode *inode, struct file *file)
 704{
 705        int ret;
 706        struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
 707
 708        mutex_lock(&nfsd_mutex);
 709        if (nn->nfsd_serv == NULL) {
 710                mutex_unlock(&nfsd_mutex);
 711                return -ENODEV;
 712        }
 713        /* bump up the psudo refcount while traversing */
 714        svc_get(nn->nfsd_serv);
 715        ret = svc_pool_stats_open(nn->nfsd_serv, file);
 716        mutex_unlock(&nfsd_mutex);
 717        return ret;
 718}
 719
 720int nfsd_pool_stats_release(struct inode *inode, struct file *file)
 721{
 722        int ret = seq_release(inode, file);
 723        struct net *net = inode->i_sb->s_fs_info;
 724
 725        mutex_lock(&nfsd_mutex);
 726        /* this function really, really should have been called svc_put() */
 727        nfsd_destroy(net);
 728        mutex_unlock(&nfsd_mutex);
 729        return ret;
 730}
 731
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