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/fs_struct.h>
12 #include <linux/swap.h>
14 #include <linux/sunrpc/stats.h>
15 #include <linux/sunrpc/svcsock.h>
16 #include <linux/lockd/bind.h>
17 #include <linux/nfsacl.h>
18 #include <linux/seq_file.h>
23 #define NFSDDBG_FACILITY NFSDDBG_SVC
25 extern struct svc_program nfsd_program
;
26 static int nfsd(void *vrqstp
);
27 struct timeval nfssvc_boot
;
30 * nfsd_mutex protects nfsd_serv -- both the pointer itself and the members
31 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
32 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
34 * If (out side the lock) nfsd_serv is non-NULL, then it must point to a
35 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
36 * of nfsd threads must exist and each must listed in ->sp_all_threads in each
37 * entry of ->sv_pools[].
39 * Transitions of the thread count between zero and non-zero are of particular
40 * interest since the svc_serv needs to be created and initialized at that
43 * Finally, the nfsd_mutex also protects some of the global variables that are
44 * accessed when nfsd starts and that are settable via the write_* routines in
45 * nfsctl.c. In particular:
47 * user_recovery_dirname
51 DEFINE_MUTEX(nfsd_mutex
);
52 struct svc_serv
*nfsd_serv
;
55 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
56 * nfsd_drc_max_pages limits the total amount of memory available for
57 * version 4.1 DRC caches.
58 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
60 spinlock_t nfsd_drc_lock
;
61 unsigned int nfsd_drc_max_mem
;
62 unsigned int nfsd_drc_mem_used
;
64 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
65 static struct svc_stat nfsd_acl_svcstats
;
66 static struct svc_version
* nfsd_acl_version
[] = {
67 [2] = &nfsd_acl_version2
,
68 [3] = &nfsd_acl_version3
,
71 #define NFSD_ACL_MINVERS 2
72 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
73 static struct svc_version
*nfsd_acl_versions
[NFSD_ACL_NRVERS
];
75 static struct svc_program nfsd_acl_program
= {
76 .pg_prog
= NFS_ACL_PROGRAM
,
77 .pg_nvers
= NFSD_ACL_NRVERS
,
78 .pg_vers
= nfsd_acl_versions
,
81 .pg_stats
= &nfsd_acl_svcstats
,
82 .pg_authenticate
= &svc_set_client
,
85 static struct svc_stat nfsd_acl_svcstats
= {
86 .program
= &nfsd_acl_program
,
88 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
90 static struct svc_version
* nfsd_version
[] = {
92 #if defined(CONFIG_NFSD_V3)
95 #if defined(CONFIG_NFSD_V4)
100 #define NFSD_MINVERS 2
101 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
102 static struct svc_version
*nfsd_versions
[NFSD_NRVERS
];
104 struct svc_program nfsd_program
= {
105 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
106 .pg_next
= &nfsd_acl_program
,
108 .pg_prog
= NFS_PROGRAM
, /* program number */
109 .pg_nvers
= NFSD_NRVERS
, /* nr of entries in nfsd_version */
110 .pg_vers
= nfsd_versions
, /* version table */
111 .pg_name
= "nfsd", /* program name */
112 .pg_class
= "nfsd", /* authentication class */
113 .pg_stats
= &nfsd_svcstats
, /* version table */
114 .pg_authenticate
= &svc_set_client
, /* export authentication */
118 u32 nfsd_supported_minorversion
;
120 int nfsd_vers(int vers
, enum vers_op change
)
122 if (vers
< NFSD_MINVERS
|| vers
>= NFSD_NRVERS
)
126 nfsd_versions
[vers
] = nfsd_version
[vers
];
127 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
128 if (vers
< NFSD_ACL_NRVERS
)
129 nfsd_acl_versions
[vers
] = nfsd_acl_version
[vers
];
133 nfsd_versions
[vers
] = NULL
;
134 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
135 if (vers
< NFSD_ACL_NRVERS
)
136 nfsd_acl_versions
[vers
] = NULL
;
140 return nfsd_versions
[vers
] != NULL
;
142 return nfsd_version
[vers
] != NULL
;
147 int nfsd_minorversion(u32 minorversion
, enum vers_op change
)
149 if (minorversion
> NFSD_SUPPORTED_MINOR_VERSION
)
153 nfsd_supported_minorversion
= minorversion
;
156 if (minorversion
== 0)
158 nfsd_supported_minorversion
= minorversion
- 1;
161 return minorversion
<= nfsd_supported_minorversion
;
163 return minorversion
<= NFSD_SUPPORTED_MINOR_VERSION
;
169 * Maximum number of nfsd processes
171 #define NFSD_MAXSERVS 8192
173 int nfsd_nrthreads(void)
176 mutex_lock(&nfsd_mutex
);
178 rv
= nfsd_serv
->sv_nrthreads
;
179 mutex_unlock(&nfsd_mutex
);
183 static int nfsd_init_socks(int port
)
186 if (!list_empty(&nfsd_serv
->sv_permsocks
))
189 error
= svc_create_xprt(nfsd_serv
, "udp", PF_INET
, port
,
194 error
= svc_create_xprt(nfsd_serv
, "tcp", PF_INET
, port
,
202 static bool nfsd_up
= false;
204 static int nfsd_startup(unsigned short port
, int nrservs
)
211 * Readahead param cache - will no-op if it already exists.
212 * (Note therefore results will be suboptimal if number of
213 * threads is modified after nfsd start.)
215 ret
= nfsd_racache_init(2*nrservs
);
218 ret
= nfsd_init_socks(port
);
224 ret
= nfs4_state_start();
232 nfsd_racache_shutdown();
236 static void nfsd_shutdown(void)
239 * write_ports can create the server without actually starting
240 * any threads--if we get shut down before any threads are
241 * started, then nfsd_last_thread will be run before any of this
242 * other initialization has been done.
246 nfs4_state_shutdown();
248 nfsd_racache_shutdown();
252 static void nfsd_last_thread(struct svc_serv
*serv
)
254 /* When last nfsd thread exits we need to do some clean-up */
258 printk(KERN_WARNING
"nfsd: last server has exited, flushing export "
263 void nfsd_reset_versions(void)
268 for (i
= NFSD_MINVERS
; i
< NFSD_NRVERS
; i
++) {
269 if (nfsd_program
.pg_vers
[i
])
274 for (i
= NFSD_MINVERS
; i
< NFSD_NRVERS
; i
++)
275 nfsd_program
.pg_vers
[i
] = nfsd_version
[i
];
276 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
277 for (i
= NFSD_ACL_MINVERS
; i
< NFSD_ACL_NRVERS
; i
++)
278 nfsd_acl_program
.pg_vers
[i
] =
285 * Each session guarantees a negotiated per slot memory cache for replies
286 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
287 * NFSv4.1 server might want to use more memory for a DRC than a machine
288 * with mutiple services.
290 * Impose a hard limit on the number of pages for the DRC which varies
291 * according to the machines free pages. This is of course only a default.
293 * For now this is a #defined shift which could be under admin control
296 static void set_max_drc(void)
298 #define NFSD_DRC_SIZE_SHIFT 10
299 nfsd_drc_max_mem
= (nr_free_buffer_pages()
300 >> NFSD_DRC_SIZE_SHIFT
) * PAGE_SIZE
;
301 nfsd_drc_mem_used
= 0;
302 spin_lock_init(&nfsd_drc_lock
);
303 dprintk("%s nfsd_drc_max_mem %u \n", __func__
, nfsd_drc_max_mem
);
306 int nfsd_create_serv(void)
310 WARN_ON(!mutex_is_locked(&nfsd_mutex
));
315 if (nfsd_max_blksize
== 0) {
316 /* choose a suitable default */
319 /* Aim for 1/4096 of memory per thread
320 * This gives 1MB on 4Gig machines
321 * But only uses 32K on 128M machines.
322 * Bottom out at 8K on 32M and smaller.
323 * Of course, this is only a default.
325 nfsd_max_blksize
= NFSSVC_MAXBLKSIZE
;
326 i
.totalram
<<= PAGE_SHIFT
- 12;
327 while (nfsd_max_blksize
> i
.totalram
&&
328 nfsd_max_blksize
>= 8*1024*2)
329 nfsd_max_blksize
/= 2;
331 nfsd_reset_versions();
333 nfsd_serv
= svc_create_pooled(&nfsd_program
, nfsd_max_blksize
,
334 nfsd_last_thread
, nfsd
, THIS_MODULE
);
335 if (nfsd_serv
== NULL
)
339 do_gettimeofday(&nfssvc_boot
); /* record boot time */
343 int nfsd_nrpools(void)
345 if (nfsd_serv
== NULL
)
348 return nfsd_serv
->sv_nrpools
;
351 int nfsd_get_nrthreads(int n
, int *nthreads
)
355 if (nfsd_serv
!= NULL
) {
356 for (i
= 0; i
< nfsd_serv
->sv_nrpools
&& i
< n
; i
++)
357 nthreads
[i
] = nfsd_serv
->sv_pools
[i
].sp_nrthreads
;
363 int nfsd_set_nrthreads(int n
, int *nthreads
)
369 WARN_ON(!mutex_is_locked(&nfsd_mutex
));
371 if (nfsd_serv
== NULL
|| n
<= 0)
374 if (n
> nfsd_serv
->sv_nrpools
)
375 n
= nfsd_serv
->sv_nrpools
;
377 /* enforce a global maximum number of threads */
379 for (i
= 0; i
< n
; i
++) {
380 if (nthreads
[i
] > NFSD_MAXSERVS
)
381 nthreads
[i
] = NFSD_MAXSERVS
;
384 if (tot
> NFSD_MAXSERVS
) {
385 /* total too large: scale down requested numbers */
386 for (i
= 0; i
< n
&& tot
> 0; i
++) {
387 int new = nthreads
[i
] * NFSD_MAXSERVS
/ tot
;
388 tot
-= (nthreads
[i
] - new);
391 for (i
= 0; i
< n
&& tot
> 0; i
++) {
398 * There must always be a thread in pool 0; the admin
399 * can't shut down NFS completely using pool_threads.
401 if (nthreads
[0] == 0)
404 /* apply the new numbers */
406 for (i
= 0; i
< n
; i
++) {
407 err
= svc_set_num_threads(nfsd_serv
, &nfsd_serv
->sv_pools
[i
],
412 svc_destroy(nfsd_serv
);
418 * Adjust the number of threads and return the new number of threads.
419 * This is also the function that starts the server if necessary, if
420 * this is the first time nrservs is nonzero.
423 nfsd_svc(unsigned short port
, int nrservs
)
428 mutex_lock(&nfsd_mutex
);
429 dprintk("nfsd: creating service\n");
432 if (nrservs
> NFSD_MAXSERVS
)
433 nrservs
= NFSD_MAXSERVS
;
435 if (nrservs
== 0 && nfsd_serv
== NULL
)
438 error
= nfsd_create_serv();
442 nfsd_up_before
= nfsd_up
;
444 error
= nfsd_startup(port
, nrservs
);
447 error
= svc_set_num_threads(nfsd_serv
, NULL
, nrservs
);
450 /* We are holding a reference to nfsd_serv which
451 * we don't want to count in the return value,
454 error
= nfsd_serv
->sv_nrthreads
- 1;
456 if (error
< 0 && !nfsd_up_before
)
459 svc_destroy(nfsd_serv
); /* Release server */
461 mutex_unlock(&nfsd_mutex
);
467 * This is the NFS server kernel thread
472 struct svc_rqst
*rqstp
= (struct svc_rqst
*) vrqstp
;
473 int err
, preverr
= 0;
475 /* Lock module and set up kernel thread */
476 mutex_lock(&nfsd_mutex
);
478 /* At this point, the thread shares current->fs
479 * with the init process. We need to create files with a
480 * umask of 0 instead of init's umask. */
481 if (unshare_fs_struct() < 0) {
482 printk("Unable to start nfsd thread: out of memory\n");
486 current
->fs
->umask
= 0;
489 * thread is spawned with all signals set to SIG_IGN, re-enable
490 * the ones that will bring down the thread
492 allow_signal(SIGKILL
);
493 allow_signal(SIGHUP
);
494 allow_signal(SIGINT
);
495 allow_signal(SIGQUIT
);
498 mutex_unlock(&nfsd_mutex
);
501 * We want less throttling in balance_dirty_pages() so that nfs to
502 * localhost doesn't cause nfsd to lock up due to all the client's
505 current
->flags
|= PF_LESS_THROTTLE
;
509 * The main request loop
513 * Find a socket with data available and call its
516 while ((err
= svc_recv(rqstp
, 60*60*HZ
)) == -EAGAIN
)
521 if (err
!= preverr
) {
522 printk(KERN_WARNING
"%s: unexpected error "
523 "from svc_recv (%d)\n", __func__
, -err
);
526 schedule_timeout_uninterruptible(HZ
);
531 /* Lock the export hash tables for reading. */
534 validate_process_creds();
536 validate_process_creds();
538 /* Unlock export hash tables */
542 /* Clear signals before calling svc_exit_thread() */
543 flush_signals(current
);
545 mutex_lock(&nfsd_mutex
);
549 /* Release the thread */
550 svc_exit_thread(rqstp
);
553 mutex_unlock(&nfsd_mutex
);
554 module_put_and_exit(0);
558 static __be32
map_new_errors(u32 vers
, __be32 nfserr
)
560 if (nfserr
== nfserr_jukebox
&& vers
== 2)
561 return nfserr_dropit
;
562 if (nfserr
== nfserr_wrongsec
&& vers
< 4)
568 nfsd_dispatch(struct svc_rqst
*rqstp
, __be32
*statp
)
570 struct svc_procedure
*proc
;
575 dprintk("nfsd_dispatch: vers %d proc %d\n",
576 rqstp
->rq_vers
, rqstp
->rq_proc
);
577 proc
= rqstp
->rq_procinfo
;
579 /* Check whether we have this call in the cache. */
580 switch (nfsd_cache_lookup(rqstp
, proc
->pc_cachetype
)) {
590 /* Decode arguments */
591 xdr
= proc
->pc_decode
;
592 if (xdr
&& !xdr(rqstp
, (__be32
*)rqstp
->rq_arg
.head
[0].iov_base
,
594 dprintk("nfsd: failed to decode arguments!\n");
595 nfsd_cache_update(rqstp
, RC_NOCACHE
, NULL
);
596 *statp
= rpc_garbage_args
;
600 /* need to grab the location to store the status, as
601 * nfsv4 does some encoding while processing
603 nfserrp
= rqstp
->rq_res
.head
[0].iov_base
604 + rqstp
->rq_res
.head
[0].iov_len
;
605 rqstp
->rq_res
.head
[0].iov_len
+= sizeof(__be32
);
607 /* Now call the procedure handler, and encode NFS status. */
608 nfserr
= proc
->pc_func(rqstp
, rqstp
->rq_argp
, rqstp
->rq_resp
);
609 nfserr
= map_new_errors(rqstp
->rq_vers
, nfserr
);
610 if (nfserr
== nfserr_dropit
) {
611 dprintk("nfsd: Dropping request; may be revisited later\n");
612 nfsd_cache_update(rqstp
, RC_NOCACHE
, NULL
);
616 if (rqstp
->rq_proc
!= 0)
620 * For NFSv2, additional info is never returned in case of an error.
622 if (!(nfserr
&& rqstp
->rq_vers
== 2)) {
623 xdr
= proc
->pc_encode
;
624 if (xdr
&& !xdr(rqstp
, nfserrp
,
626 /* Failed to encode result. Release cache entry */
627 dprintk("nfsd: failed to encode result!\n");
628 nfsd_cache_update(rqstp
, RC_NOCACHE
, NULL
);
629 *statp
= rpc_system_err
;
634 /* Store reply in cache. */
635 nfsd_cache_update(rqstp
, proc
->pc_cachetype
, statp
+ 1);
639 int nfsd_pool_stats_open(struct inode
*inode
, struct file
*file
)
642 mutex_lock(&nfsd_mutex
);
643 if (nfsd_serv
== NULL
) {
644 mutex_unlock(&nfsd_mutex
);
647 /* bump up the psudo refcount while traversing */
649 ret
= svc_pool_stats_open(nfsd_serv
, file
);
650 mutex_unlock(&nfsd_mutex
);
654 int nfsd_pool_stats_release(struct inode
*inode
, struct file
*file
)
656 int ret
= seq_release(inode
, file
);
657 mutex_lock(&nfsd_mutex
);
658 /* this function really, really should have been called svc_put() */
659 svc_destroy(nfsd_serv
);
660 mutex_unlock(&nfsd_mutex
);