2 * Central processing for nfsd.
4 * Authors: Olaf Kirch (okir@monad.swb.de)
6 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
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>
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>
26 #define NFSDDBG_FACILITY NFSDDBG_SVC
28 extern struct svc_program nfsd_program;
29 static int nfsd(void *vrqstp);
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
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[].
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
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:
49 * user_recovery_dirname
53 DEFINE_MUTEX(nfsd_mutex);
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.
61 spinlock_t nfsd_drc_lock;
62 unsigned long nfsd_drc_max_mem;
63 unsigned long nfsd_drc_mem_used;
65 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
66 static struct svc_stat nfsd_acl_svcstats;
67 static struct svc_version * nfsd_acl_version[] = {
68 [2] = &nfsd_acl_version2,
69 [3] = &nfsd_acl_version3,
72 #define NFSD_ACL_MINVERS 2
73 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
74 static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
76 static struct svc_program nfsd_acl_program = {
77 .pg_prog = NFS_ACL_PROGRAM,
78 .pg_nvers = NFSD_ACL_NRVERS,
79 .pg_vers = nfsd_acl_versions,
82 .pg_stats = &nfsd_acl_svcstats,
83 .pg_authenticate = &svc_set_client,
86 static struct svc_stat nfsd_acl_svcstats = {
87 .program = &nfsd_acl_program,
89 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
91 static struct svc_version * nfsd_version[] = {
93 #if defined(CONFIG_NFSD_V3)
96 #if defined(CONFIG_NFSD_V4)
101 #define NFSD_MINVERS 2
102 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
103 static struct svc_version *nfsd_versions[NFSD_NRVERS];
105 struct svc_program nfsd_program = {
106 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
107 .pg_next = &nfsd_acl_program,
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 */
119 static bool nfsd_supported_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1] = {
125 int nfsd_vers(int vers, enum vers_op change)
127 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
131 nfsd_versions[vers] = nfsd_version[vers];
132 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
133 if (vers < NFSD_ACL_NRVERS)
134 nfsd_acl_versions[vers] = nfsd_acl_version[vers];
138 nfsd_versions[vers] = NULL;
139 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
140 if (vers < NFSD_ACL_NRVERS)
141 nfsd_acl_versions[vers] = NULL;
145 return nfsd_versions[vers] != NULL;
147 return nfsd_version[vers] != NULL;
152 int nfsd_minorversion(u32 minorversion, enum vers_op change)
154 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
155 change != NFSD_AVAIL)
159 nfsd_supported_minorversions[minorversion] = true;
162 nfsd_supported_minorversions[minorversion] = false;
165 return nfsd_supported_minorversions[minorversion];
167 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
173 * Maximum number of nfsd processes
175 #define NFSD_MAXSERVS 8192
177 int nfsd_nrthreads(struct net *net)
180 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
182 mutex_lock(&nfsd_mutex);
184 rv = nn->nfsd_serv->sv_nrthreads;
185 mutex_unlock(&nfsd_mutex);
189 static int nfsd_init_socks(struct net *net)
192 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
194 if (!list_empty(&nn->nfsd_serv->sv_permsocks))
197 error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
202 error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
210 static int nfsd_users = 0;
212 static int nfsd_startup_generic(int nrservs)
220 * Readahead param cache - will no-op if it already exists.
221 * (Note therefore results will be suboptimal if number of
222 * threads is modified after nfsd start.)
224 ret = nfsd_racache_init(2*nrservs);
228 ret = nfs4_state_start();
234 nfsd_racache_shutdown();
240 static void nfsd_shutdown_generic(void)
245 nfs4_state_shutdown();
246 nfsd_racache_shutdown();
249 static bool nfsd_needs_lockd(void)
251 #if defined(CONFIG_NFSD_V3)
252 return (nfsd_versions[2] != NULL) || (nfsd_versions[3] != NULL);
254 return (nfsd_versions[2] != NULL);
258 static int nfsd_startup_net(int nrservs, struct net *net)
260 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
266 ret = nfsd_startup_generic(nrservs);
269 ret = nfsd_init_socks(net);
273 if (nfsd_needs_lockd() && !nn->lockd_up) {
280 ret = nfs4_state_start_net(net);
284 nn->nfsd_net_up = true;
293 nfsd_shutdown_generic();
297 static void nfsd_shutdown_net(struct net *net)
299 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
301 nfs4_state_shutdown_net(net);
306 nn->nfsd_net_up = false;
307 nfsd_shutdown_generic();
310 static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
312 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
315 * write_ports can create the server without actually starting
316 * any threads--if we get shut down before any threads are
317 * started, then nfsd_last_thread will be run before any of this
318 * other initialization has been done.
320 if (!nn->nfsd_net_up)
322 nfsd_shutdown_net(net);
324 svc_rpcb_cleanup(serv, net);
326 printk(KERN_WARNING "nfsd: last server has exited, flushing export "
328 nfsd_export_flush(net);
331 void nfsd_reset_versions(void)
335 for (i = 0; i < NFSD_NRVERS; i++)
336 if (nfsd_vers(i, NFSD_TEST))
339 for (i = 0; i < NFSD_NRVERS; i++)
341 nfsd_vers(i, NFSD_SET);
344 while (nfsd_minorversion(minor, NFSD_SET) >= 0)
350 * Each session guarantees a negotiated per slot memory cache for replies
351 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
352 * NFSv4.1 server might want to use more memory for a DRC than a machine
353 * with mutiple services.
355 * Impose a hard limit on the number of pages for the DRC which varies
356 * according to the machines free pages. This is of course only a default.
358 * For now this is a #defined shift which could be under admin control
361 static void set_max_drc(void)
363 #define NFSD_DRC_SIZE_SHIFT 7
364 nfsd_drc_max_mem = (nr_free_buffer_pages()
365 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
366 nfsd_drc_mem_used = 0;
367 spin_lock_init(&nfsd_drc_lock);
368 dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
371 static int nfsd_get_default_max_blksize(void)
374 unsigned long long target;
378 target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
380 * Aim for 1/4096 of memory per thread This gives 1MB on 4Gig
381 * machines, but only uses 32K on 128M machines. Bottom out at
382 * 8K on 32M and smaller. Of course, this is only a default.
386 ret = NFSSVC_MAXBLKSIZE;
387 while (ret > target && ret >= 8*1024*2)
392 static struct svc_serv_ops nfsd_thread_sv_ops = {
393 .svo_shutdown = nfsd_last_thread,
394 .svo_function = nfsd,
395 .svo_enqueue_xprt = svc_xprt_do_enqueue,
396 .svo_setup = svc_set_num_threads,
397 .svo_module = THIS_MODULE,
400 int nfsd_create_serv(struct net *net)
403 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
405 WARN_ON(!mutex_is_locked(&nfsd_mutex));
407 svc_get(nn->nfsd_serv);
410 if (nfsd_max_blksize == 0)
411 nfsd_max_blksize = nfsd_get_default_max_blksize();
412 nfsd_reset_versions();
413 nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
414 &nfsd_thread_sv_ops);
415 if (nn->nfsd_serv == NULL)
418 nn->nfsd_serv->sv_maxconn = nn->max_connections;
419 error = svc_bind(nn->nfsd_serv, net);
421 svc_destroy(nn->nfsd_serv);
426 do_gettimeofday(&nn->nfssvc_boot); /* record boot time */
430 int nfsd_nrpools(struct net *net)
432 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
434 if (nn->nfsd_serv == NULL)
437 return nn->nfsd_serv->sv_nrpools;
440 int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
443 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
445 if (nn->nfsd_serv != NULL) {
446 for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
447 nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
453 void nfsd_destroy(struct net *net)
455 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
456 int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
459 svc_shutdown_net(nn->nfsd_serv, net);
460 svc_destroy(nn->nfsd_serv);
462 nn->nfsd_serv = NULL;
465 int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
470 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
472 WARN_ON(!mutex_is_locked(&nfsd_mutex));
474 if (nn->nfsd_serv == NULL || n <= 0)
477 if (n > nn->nfsd_serv->sv_nrpools)
478 n = nn->nfsd_serv->sv_nrpools;
480 /* enforce a global maximum number of threads */
482 for (i = 0; i < n; i++) {
483 nthreads[i] = min(nthreads[i], NFSD_MAXSERVS);
486 if (tot > NFSD_MAXSERVS) {
487 /* total too large: scale down requested numbers */
488 for (i = 0; i < n && tot > 0; i++) {
489 int new = nthreads[i] * NFSD_MAXSERVS / tot;
490 tot -= (nthreads[i] - new);
493 for (i = 0; i < n && tot > 0; i++) {
500 * There must always be a thread in pool 0; the admin
501 * can't shut down NFS completely using pool_threads.
503 if (nthreads[0] == 0)
506 /* apply the new numbers */
507 svc_get(nn->nfsd_serv);
508 for (i = 0; i < n; i++) {
509 err = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
510 &nn->nfsd_serv->sv_pools[i], nthreads[i]);
519 * Adjust the number of threads and return the new number of threads.
520 * This is also the function that starts the server if necessary, if
521 * this is the first time nrservs is nonzero.
524 nfsd_svc(int nrservs, struct net *net)
528 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
530 mutex_lock(&nfsd_mutex);
531 dprintk("nfsd: creating service\n");
533 nrservs = max(nrservs, 0);
534 nrservs = min(nrservs, NFSD_MAXSERVS);
537 if (nrservs == 0 && nn->nfsd_serv == NULL)
540 error = nfsd_create_serv(net);
544 nfsd_up_before = nn->nfsd_net_up;
546 error = nfsd_startup_net(nrservs, net);
549 error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
553 /* We are holding a reference to nn->nfsd_serv which
554 * we don't want to count in the return value,
557 error = nn->nfsd_serv->sv_nrthreads - 1;
559 if (error < 0 && !nfsd_up_before)
560 nfsd_shutdown_net(net);
562 nfsd_destroy(net); /* Release server */
564 mutex_unlock(&nfsd_mutex);
570 * This is the NFS server kernel thread
575 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
576 struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
577 struct net *net = perm_sock->xpt_net;
578 struct nfsd_net *nn = net_generic(net, nfsd_net_id);
581 /* Lock module and set up kernel thread */
582 mutex_lock(&nfsd_mutex);
584 /* At this point, the thread shares current->fs
585 * with the init process. We need to create files with a
586 * umask of 0 instead of init's umask. */
587 if (unshare_fs_struct() < 0) {
588 printk("Unable to start nfsd thread: out of memory\n");
592 current->fs->umask = 0;
595 * thread is spawned with all signals set to SIG_IGN, re-enable
596 * the ones that will bring down the thread
598 allow_signal(SIGKILL);
599 allow_signal(SIGHUP);
600 allow_signal(SIGINT);
601 allow_signal(SIGQUIT);
604 mutex_unlock(&nfsd_mutex);
609 * The main request loop
612 /* Update sv_maxconn if it has changed */
613 rqstp->rq_server->sv_maxconn = nn->max_connections;
616 * Find a socket with data available and call its
619 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
623 validate_process_creds();
625 validate_process_creds();
628 /* Clear signals before calling svc_exit_thread() */
629 flush_signals(current);
631 mutex_lock(&nfsd_mutex);
635 rqstp->rq_server = NULL;
637 /* Release the thread */
638 svc_exit_thread(rqstp);
643 mutex_unlock(&nfsd_mutex);
644 module_put_and_exit(0);
648 static __be32 map_new_errors(u32 vers, __be32 nfserr)
650 if (nfserr == nfserr_jukebox && vers == 2)
651 return nfserr_dropit;
652 if (nfserr == nfserr_wrongsec && vers < 4)
658 * A write procedure can have a large argument, and a read procedure can
659 * have a large reply, but no NFSv2 or NFSv3 procedure has argument and
660 * reply that can both be larger than a page. The xdr code has taken
661 * advantage of this assumption to be a sloppy about bounds checking in
662 * some cases. Pending a rewrite of the NFSv2/v3 xdr code to fix that
663 * problem, we enforce these assumptions here:
665 static bool nfs_request_too_big(struct svc_rqst *rqstp,
666 struct svc_procedure *proc)
669 * The ACL code has more careful bounds-checking and is not
670 * susceptible to this problem:
672 if (rqstp->rq_prog != NFS_PROGRAM)
675 * Ditto NFSv4 (which can in theory have argument and reply both
678 if (rqstp->rq_vers >= 4)
680 /* The reply will be small, we're OK: */
681 if (proc->pc_xdrressize > 0 &&
682 proc->pc_xdrressize < XDR_QUADLEN(PAGE_SIZE))
685 return rqstp->rq_arg.len > PAGE_SIZE;
689 nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
691 struct svc_procedure *proc;
696 dprintk("nfsd_dispatch: vers %d proc %d\n",
697 rqstp->rq_vers, rqstp->rq_proc);
698 proc = rqstp->rq_procinfo;
700 if (nfs_request_too_big(rqstp, proc)) {
701 dprintk("nfsd: NFSv%d argument too large\n", rqstp->rq_vers);
702 *statp = rpc_garbage_args;
706 * Give the xdr decoder a chance to change this if it wants
707 * (necessary in the NFSv4.0 compound case)
709 rqstp->rq_cachetype = proc->pc_cachetype;
710 /* Decode arguments */
711 xdr = proc->pc_decode;
712 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
714 dprintk("nfsd: failed to decode arguments!\n");
715 *statp = rpc_garbage_args;
719 /* Check whether we have this call in the cache. */
720 switch (nfsd_cache_lookup(rqstp)) {
729 /* need to grab the location to store the status, as
730 * nfsv4 does some encoding while processing
732 nfserrp = rqstp->rq_res.head[0].iov_base
733 + rqstp->rq_res.head[0].iov_len;
734 rqstp->rq_res.head[0].iov_len += sizeof(__be32);
736 /* Now call the procedure handler, and encode NFS status. */
737 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
738 nfserr = map_new_errors(rqstp->rq_vers, nfserr);
739 if (nfserr == nfserr_dropit || test_bit(RQ_DROPME, &rqstp->rq_flags)) {
740 dprintk("nfsd: Dropping request; may be revisited later\n");
741 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
745 if (rqstp->rq_proc != 0)
749 * For NFSv2, additional info is never returned in case of an error.
751 if (!(nfserr && rqstp->rq_vers == 2)) {
752 xdr = proc->pc_encode;
753 if (xdr && !xdr(rqstp, nfserrp,
755 /* Failed to encode result. Release cache entry */
756 dprintk("nfsd: failed to encode result!\n");
757 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
758 *statp = rpc_system_err;
763 /* Store reply in cache. */
764 nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
768 int nfsd_pool_stats_open(struct inode *inode, struct file *file)
771 struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
773 mutex_lock(&nfsd_mutex);
774 if (nn->nfsd_serv == NULL) {
775 mutex_unlock(&nfsd_mutex);
778 /* bump up the psudo refcount while traversing */
779 svc_get(nn->nfsd_serv);
780 ret = svc_pool_stats_open(nn->nfsd_serv, file);
781 mutex_unlock(&nfsd_mutex);
785 int nfsd_pool_stats_release(struct inode *inode, struct file *file)
787 int ret = seq_release(inode, file);
788 struct net *net = inode->i_sb->s_fs_info;
790 mutex_lock(&nfsd_mutex);
791 /* this function really, really should have been called svc_put() */
793 mutex_unlock(&nfsd_mutex);