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OpenCloudOS-Kernel/fs/nfsd/nfssvc.c

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/*
* linux/fs/nfsd/nfssvc.c
*
* Central processing for nfsd.
*
* Authors: Olaf Kirch (okir@monad.swb.de)
*
* Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/errno.h>
#include <linux/nfs.h>
#include <linux/in.h>
#include <linux/uio.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/freezer.h>
#include <linux/fs_struct.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/cache.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/stats.h>
#include <linux/nfsd/cache.h>
#include <linux/nfsd/syscall.h>
#include <linux/lockd/bind.h>
#include <linux/nfsacl.h>
#define NFSDDBG_FACILITY NFSDDBG_SVC
/* these signals will be delivered to an nfsd thread
* when handling a request
*/
#define ALLOWED_SIGS (sigmask(SIGKILL))
/* these signals will be delivered to an nfsd thread
* when not handling a request. i.e. when waiting
*/
#define SHUTDOWN_SIGS (sigmask(SIGKILL) | sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT))
/* if the last thread dies with SIGHUP, then the exports table is
* left unchanged ( like 2.4-{0-9} ). Any other signal will clear
* the exports table (like 2.2).
*/
#define SIG_NOCLEAN SIGHUP
extern struct svc_program nfsd_program;
static void nfsd(struct svc_rqst *rqstp);
struct timeval nfssvc_boot;
struct svc_serv *nfsd_serv;
static atomic_t nfsd_busy;
static unsigned long nfsd_last_call;
static DEFINE_SPINLOCK(nfsd_call_lock);
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static struct svc_stat nfsd_acl_svcstats;
static struct svc_version * nfsd_acl_version[] = {
[2] = &nfsd_acl_version2,
[3] = &nfsd_acl_version3,
};
#define NFSD_ACL_MINVERS 2
#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
static struct svc_program nfsd_acl_program = {
.pg_prog = NFS_ACL_PROGRAM,
.pg_nvers = NFSD_ACL_NRVERS,
.pg_vers = nfsd_acl_versions,
.pg_name = "nfsacl",
.pg_class = "nfsd",
.pg_stats = &nfsd_acl_svcstats,
.pg_authenticate = &svc_set_client,
};
static struct svc_stat nfsd_acl_svcstats = {
.program = &nfsd_acl_program,
};
#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
static struct svc_version * nfsd_version[] = {
[2] = &nfsd_version2,
#if defined(CONFIG_NFSD_V3)
[3] = &nfsd_version3,
#endif
#if defined(CONFIG_NFSD_V4)
[4] = &nfsd_version4,
#endif
};
#define NFSD_MINVERS 2
#define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
static struct svc_version *nfsd_versions[NFSD_NRVERS];
struct svc_program nfsd_program = {
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
.pg_next = &nfsd_acl_program,
#endif
.pg_prog = NFS_PROGRAM, /* program number */
.pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
.pg_vers = nfsd_versions, /* version table */
.pg_name = "nfsd", /* program name */
.pg_class = "nfsd", /* authentication class */
.pg_stats = &nfsd_svcstats, /* version table */
.pg_authenticate = &svc_set_client, /* export authentication */
};
int nfsd_vers(int vers, enum vers_op change)
{
if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
return -1;
switch(change) {
case NFSD_SET:
nfsd_versions[vers] = nfsd_version[vers];
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
if (vers < NFSD_ACL_NRVERS)
nfsd_acl_versions[vers] = nfsd_acl_version[vers];
#endif
break;
case NFSD_CLEAR:
nfsd_versions[vers] = NULL;
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
if (vers < NFSD_ACL_NRVERS)
nfsd_acl_versions[vers] = NULL;
#endif
break;
case NFSD_TEST:
return nfsd_versions[vers] != NULL;
case NFSD_AVAIL:
return nfsd_version[vers] != NULL;
}
return 0;
}
/*
* Maximum number of nfsd processes
*/
#define NFSD_MAXSERVS 8192
int nfsd_nrthreads(void)
{
if (nfsd_serv == NULL)
return 0;
else
return nfsd_serv->sv_nrthreads;
}
static int killsig; /* signal that was used to kill last nfsd */
static void nfsd_last_thread(struct svc_serv *serv)
{
/* When last nfsd thread exits we need to do some clean-up */
struct svc_sock *svsk;
list_for_each_entry(svsk, &serv->sv_permsocks, sk_list)
lockd_down();
nfsd_serv = NULL;
nfsd_racache_shutdown();
nfs4_state_shutdown();
printk(KERN_WARNING "nfsd: last server has exited\n");
if (killsig != SIG_NOCLEAN) {
printk(KERN_WARNING "nfsd: unexporting all filesystems\n");
nfsd_export_flush();
}
}
void nfsd_reset_versions(void)
{
int found_one = 0;
int i;
for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
if (nfsd_program.pg_vers[i])
found_one = 1;
}
if (!found_one) {
for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
nfsd_program.pg_vers[i] = nfsd_version[i];
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
nfsd_acl_program.pg_vers[i] =
nfsd_acl_version[i];
#endif
}
}
int nfsd_create_serv(void)
{
int err = 0;
lock_kernel();
if (nfsd_serv) {
svc_get(nfsd_serv);
unlock_kernel();
return 0;
}
if (nfsd_max_blksize == 0) {
/* choose a suitable default */
struct sysinfo i;
si_meminfo(&i);
/* Aim for 1/4096 of memory per thread
* This gives 1MB on 4Gig machines
* But only uses 32K on 128M machines.
* Bottom out at 8K on 32M and smaller.
* Of course, this is only a default.
*/
nfsd_max_blksize = NFSSVC_MAXBLKSIZE;
i.totalram <<= PAGE_SHIFT - 12;
while (nfsd_max_blksize > i.totalram &&
nfsd_max_blksize >= 8*1024*2)
nfsd_max_blksize /= 2;
}
atomic_set(&nfsd_busy, 0);
nfsd_serv = svc_create_pooled(&nfsd_program,
nfsd_max_blksize,
nfsd_last_thread,
nfsd, SIG_NOCLEAN, THIS_MODULE);
if (nfsd_serv == NULL)
err = -ENOMEM;
unlock_kernel();
do_gettimeofday(&nfssvc_boot); /* record boot time */
return err;
}
static int nfsd_init_socks(int port)
{
int error;
if (!list_empty(&nfsd_serv->sv_permsocks))
return 0;
error = lockd_up(IPPROTO_UDP);
if (error >= 0) {
error = svc_makesock(nfsd_serv, IPPROTO_UDP, port,
SVC_SOCK_DEFAULTS);
if (error < 0)
lockd_down();
}
if (error < 0)
return error;
#ifdef CONFIG_NFSD_TCP
error = lockd_up(IPPROTO_TCP);
if (error >= 0) {
error = svc_makesock(nfsd_serv, IPPROTO_TCP, port,
SVC_SOCK_DEFAULTS);
if (error < 0)
lockd_down();
}
if (error < 0)
return error;
#endif
return 0;
}
int nfsd_nrpools(void)
{
if (nfsd_serv == NULL)
return 0;
else
return nfsd_serv->sv_nrpools;
}
int nfsd_get_nrthreads(int n, int *nthreads)
{
int i = 0;
if (nfsd_serv != NULL) {
for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
}
return 0;
}
int nfsd_set_nrthreads(int n, int *nthreads)
{
int i = 0;
int tot = 0;
int err = 0;
if (nfsd_serv == NULL || n <= 0)
return 0;
if (n > nfsd_serv->sv_nrpools)
n = nfsd_serv->sv_nrpools;
/* enforce a global maximum number of threads */
tot = 0;
for (i = 0; i < n; i++) {
if (nthreads[i] > NFSD_MAXSERVS)
nthreads[i] = NFSD_MAXSERVS;
tot += nthreads[i];
}
if (tot > NFSD_MAXSERVS) {
/* total too large: scale down requested numbers */
for (i = 0; i < n && tot > 0; i++) {
int new = nthreads[i] * NFSD_MAXSERVS / tot;
tot -= (nthreads[i] - new);
nthreads[i] = new;
}
for (i = 0; i < n && tot > 0; i++) {
nthreads[i]--;
tot--;
}
}
/*
* There must always be a thread in pool 0; the admin
* can't shut down NFS completely using pool_threads.
*/
if (nthreads[0] == 0)
nthreads[0] = 1;
/* apply the new numbers */
lock_kernel();
svc_get(nfsd_serv);
for (i = 0; i < n; i++) {
err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
nthreads[i]);
if (err)
break;
}
svc_destroy(nfsd_serv);
unlock_kernel();
return err;
}
int
nfsd_svc(unsigned short port, int nrservs)
{
int error;
lock_kernel();
dprintk("nfsd: creating service\n");
error = -EINVAL;
if (nrservs <= 0)
nrservs = 0;
if (nrservs > NFSD_MAXSERVS)
nrservs = NFSD_MAXSERVS;
/* Readahead param cache - will no-op if it already exists */
error = nfsd_racache_init(2*nrservs);
if (error<0)
goto out;
nfs4_state_start();
nfsd_reset_versions();
error = nfsd_create_serv();
if (error)
goto out;
error = nfsd_init_socks(port);
if (error)
goto failure;
error = svc_set_num_threads(nfsd_serv, NULL, nrservs);
failure:
svc_destroy(nfsd_serv); /* Release server */
out:
unlock_kernel();
return error;
}
static inline void
update_thread_usage(int busy_threads)
{
unsigned long prev_call;
unsigned long diff;
int decile;
spin_lock(&nfsd_call_lock);
prev_call = nfsd_last_call;
nfsd_last_call = jiffies;
decile = busy_threads*10/nfsdstats.th_cnt;
if (decile>0 && decile <= 10) {
diff = nfsd_last_call - prev_call;
if ( (nfsdstats.th_usage[decile-1] += diff) >= NFSD_USAGE_WRAP)
nfsdstats.th_usage[decile-1] -= NFSD_USAGE_WRAP;
if (decile == 10)
nfsdstats.th_fullcnt++;
}
spin_unlock(&nfsd_call_lock);
}
/*
* This is the NFS server kernel thread
*/
static void
nfsd(struct svc_rqst *rqstp)
{
struct fs_struct *fsp;
int err;
sigset_t shutdown_mask, allowed_mask;
/* Lock module and set up kernel thread */
lock_kernel();
daemonize("nfsd");
/* After daemonize() this kernel thread shares current->fs
* with the init process. We need to create files with a
* umask of 0 instead of init's umask. */
fsp = copy_fs_struct(current->fs);
if (!fsp) {
printk("Unable to start nfsd thread: out of memory\n");
goto out;
}
exit_fs(current);
current->fs = fsp;
current->fs->umask = 0;
siginitsetinv(&shutdown_mask, SHUTDOWN_SIGS);
siginitsetinv(&allowed_mask, ALLOWED_SIGS);
nfsdstats.th_cnt++;
rqstp->rq_task = current;
unlock_kernel();
/*
* We want less throttling in balance_dirty_pages() so that nfs to
* localhost doesn't cause nfsd to lock up due to all the client's
* dirty pages.
*/
current->flags |= PF_LESS_THROTTLE;
set_freezable();
/*
* The main request loop
*/
for (;;) {
/* Block all but the shutdown signals */
sigprocmask(SIG_SETMASK, &shutdown_mask, NULL);
/*
* Find a socket with data available and call its
* recvfrom routine.
*/
while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
;
if (err < 0)
break;
update_thread_usage(atomic_read(&nfsd_busy));
atomic_inc(&nfsd_busy);
/* Lock the export hash tables for reading. */
exp_readlock();
/* Process request with signals blocked. */
sigprocmask(SIG_SETMASK, &allowed_mask, NULL);
svc_process(rqstp);
/* Unlock export hash tables */
exp_readunlock();
update_thread_usage(atomic_read(&nfsd_busy));
atomic_dec(&nfsd_busy);
}
if (err != -EINTR) {
printk(KERN_WARNING "nfsd: terminating on error %d\n", -err);
} else {
unsigned int signo;
for (signo = 1; signo <= _NSIG; signo++)
if (sigismember(&current->pending.signal, signo) &&
!sigismember(&current->blocked, signo))
break;
killsig = signo;
}
/* Clear signals before calling svc_exit_thread() */
flush_signals(current);
lock_kernel();
nfsdstats.th_cnt --;
out:
/* Release the thread */
svc_exit_thread(rqstp);
/* Release module */
unlock_kernel();
module_put_and_exit(0);
}
static __be32 map_new_errors(u32 vers, __be32 nfserr)
{
if (nfserr == nfserr_jukebox && vers == 2)
return nfserr_dropit;
if (nfserr == nfserr_wrongsec && vers < 4)
return nfserr_acces;
return nfserr;
}
int
nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
{
struct svc_procedure *proc;
kxdrproc_t xdr;
__be32 nfserr;
__be32 *nfserrp;
dprintk("nfsd_dispatch: vers %d proc %d\n",
rqstp->rq_vers, rqstp->rq_proc);
proc = rqstp->rq_procinfo;
/* Check whether we have this call in the cache. */
switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
case RC_INTR:
case RC_DROPIT:
return 0;
case RC_REPLY:
return 1;
case RC_DOIT:;
/* do it */
}
/* Decode arguments */
xdr = proc->pc_decode;
if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
rqstp->rq_argp)) {
dprintk("nfsd: failed to decode arguments!\n");
nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
*statp = rpc_garbage_args;
return 1;
}
/* need to grab the location to store the status, as
* nfsv4 does some encoding while processing
*/
nfserrp = rqstp->rq_res.head[0].iov_base
+ rqstp->rq_res.head[0].iov_len;
rqstp->rq_res.head[0].iov_len += sizeof(__be32);
/* Now call the procedure handler, and encode NFS status. */
nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
nfserr = map_new_errors(rqstp->rq_vers, nfserr);
if (nfserr == nfserr_dropit) {
dprintk("nfsd: Dropping request; may be revisited later\n");
nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
return 0;
}
if (rqstp->rq_proc != 0)
*nfserrp++ = nfserr;
/* Encode result.
* For NFSv2, additional info is never returned in case of an error.
*/
if (!(nfserr && rqstp->rq_vers == 2)) {
xdr = proc->pc_encode;
if (xdr && !xdr(rqstp, nfserrp,
rqstp->rq_resp)) {
/* Failed to encode result. Release cache entry */
dprintk("nfsd: failed to encode result!\n");
nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
*statp = rpc_system_err;
return 1;
}
}
/* Store reply in cache. */
nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
return 1;
}
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