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nfssvc.c
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// SPDX-License-Identifier: GPL-2.0
/*
* Central processing for nfsd.
*
* Authors: Olaf Kirch (okir@monad.swb.de)
*
* Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/sched/signal.h>
#include <linux/freezer.h>
#include <linux/module.h>
#include <linux/fs_struct.h>
#include <linux/swap.h>
#include <linux/sunrpc/stats.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/svc_xprt.h>
#include <linux/lockd/bind.h>
#include <linux/nfsacl.h>
#include <linux/seq_file.h>
#include <linux/inetdevice.h>
#include <net/addrconf.h>
#include <net/ipv6.h>
#include <net/net_namespace.h>
#include "nfsd.h"
#include "cache.h"
#include "vfs.h"
#include "netns.h"
#include "filecache.h"
#define NFSDDBG_FACILITY NFSDDBG_SVC
bool inter_copy_offload_enable;
EXPORT_SYMBOL_GPL(inter_copy_offload_enable);
module_param(inter_copy_offload_enable, bool, 0644);
MODULE_PARM_DESC(inter_copy_offload_enable,
"Enable inter server to server copy offload. Default: false");
extern struct svc_program nfsd_program;
static int nfsd(void *vrqstp);
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static int nfsd_acl_rpcbind_set(struct net *,
const struct svc_program *,
u32, int,
unsigned short,
unsigned short);
static __be32 nfsd_acl_init_request(struct svc_rqst *,
const struct svc_program *,
struct svc_process_info *);
#endif
static int nfsd_rpcbind_set(struct net *,
const struct svc_program *,
u32, int,
unsigned short,
unsigned short);
static __be32 nfsd_init_request(struct svc_rqst *,
const struct svc_program *,
struct svc_process_info *);
/*
* nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members
* of the svc_serv struct. In particular, ->sv_nrthreads but also to some
* extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
*
* If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a
* properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
* of nfsd threads must exist and each must listed in ->sp_all_threads in each
* entry of ->sv_pools[].
*
* Transitions of the thread count between zero and non-zero are of particular
* interest since the svc_serv needs to be created and initialized at that
* point, or freed.
*
* Finally, the nfsd_mutex also protects some of the global variables that are
* accessed when nfsd starts and that are settable via the write_* routines in
* nfsctl.c. In particular:
*
* user_recovery_dirname
* user_lease_time
* nfsd_versions
*/
DEFINE_MUTEX(nfsd_mutex);
/*
* nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
* nfsd_drc_max_pages limits the total amount of memory available for
* version 4.1 DRC caches.
* nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
*/
spinlock_t nfsd_drc_lock;
unsigned long nfsd_drc_max_mem;
unsigned long nfsd_drc_mem_used;
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static struct svc_stat nfsd_acl_svcstats;
static const 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_program nfsd_acl_program = {
.pg_prog = NFS_ACL_PROGRAM,
.pg_nvers = NFSD_ACL_NRVERS,
.pg_vers = nfsd_acl_version,
.pg_name = "nfsacl",
.pg_class = "nfsd",
.pg_stats = &nfsd_acl_svcstats,
.pg_authenticate = &svc_set_client,
.pg_init_request = nfsd_acl_init_request,
.pg_rpcbind_set = nfsd_acl_rpcbind_set,
};
static struct svc_stat nfsd_acl_svcstats = {
.program = &nfsd_acl_program,
};
#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
static const 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)
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_version, /* 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 */
.pg_init_request = nfsd_init_request,
.pg_rpcbind_set = nfsd_rpcbind_set,
};
static bool
nfsd_support_version(int vers)
{
if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS)
return nfsd_version[vers] != NULL;
return false;
}
static bool *
nfsd_alloc_versions(void)
{
bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL);
unsigned i;
if (vers) {
/* All compiled versions are enabled by default */
for (i = 0; i < NFSD_NRVERS; i++)
vers[i] = nfsd_support_version(i);
}
return vers;
}
static bool *
nfsd_alloc_minorversions(void)
{
bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1,
sizeof(bool), GFP_KERNEL);
unsigned i;
if (vers) {
/* All minor versions are enabled by default */
for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++)
vers[i] = nfsd_support_version(4);
}
return vers;
}
void
nfsd_netns_free_versions(struct nfsd_net *nn)
{
kfree(nn->nfsd_versions);
kfree(nn->nfsd4_minorversions);
nn->nfsd_versions = NULL;
nn->nfsd4_minorversions = NULL;
}
static void
nfsd_netns_init_versions(struct nfsd_net *nn)
{
if (!nn->nfsd_versions) {
nn->nfsd_versions = nfsd_alloc_versions();
nn->nfsd4_minorversions = nfsd_alloc_minorversions();
if (!nn->nfsd_versions || !nn->nfsd4_minorversions)
nfsd_netns_free_versions(nn);
}
}
int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change)
{
if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
return 0;
switch(change) {
case NFSD_SET:
if (nn->nfsd_versions)
nn->nfsd_versions[vers] = nfsd_support_version(vers);
break;
case NFSD_CLEAR:
nfsd_netns_init_versions(nn);
if (nn->nfsd_versions)
nn->nfsd_versions[vers] = false;
break;
case NFSD_TEST:
if (nn->nfsd_versions)
return nn->nfsd_versions[vers];
/* Fallthrough */
case NFSD_AVAIL:
return nfsd_support_version(vers);
}
return 0;
}
static void
nfsd_adjust_nfsd_versions4(struct nfsd_net *nn)
{
unsigned i;
for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
if (nn->nfsd4_minorversions[i])
return;
}
nfsd_vers(nn, 4, NFSD_CLEAR);
}
int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change)
{
if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
change != NFSD_AVAIL)
return -1;
switch(change) {
case NFSD_SET:
if (nn->nfsd4_minorversions) {
nfsd_vers(nn, 4, NFSD_SET);
nn->nfsd4_minorversions[minorversion] =
nfsd_vers(nn, 4, NFSD_TEST);
}
break;
case NFSD_CLEAR:
nfsd_netns_init_versions(nn);
if (nn->nfsd4_minorversions) {
nn->nfsd4_minorversions[minorversion] = false;
nfsd_adjust_nfsd_versions4(nn);
}
break;
case NFSD_TEST:
if (nn->nfsd4_minorversions)
return nn->nfsd4_minorversions[minorversion];
return nfsd_vers(nn, 4, NFSD_TEST);
case NFSD_AVAIL:
return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
nfsd_vers(nn, 4, NFSD_AVAIL);
}
return 0;
}
/*
* Maximum number of nfsd processes
*/
#define NFSD_MAXSERVS 8192
int nfsd_nrthreads(struct net *net)
{
int rv = 0;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
mutex_lock(&nfsd_mutex);
if (nn->nfsd_serv)
rv = nn->nfsd_serv->sv_nrthreads;
mutex_unlock(&nfsd_mutex);
return rv;
}
static int nfsd_init_socks(struct net *net, const struct cred *cred)
{
int error;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (!list_empty(&nn->nfsd_serv->sv_permsocks))
return 0;
error = svc_create_xprt(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
SVC_SOCK_DEFAULTS, cred);
if (error < 0)
return error;
error = svc_create_xprt(nn->nfsd_serv, "tcp", net, PF_INET, NFS_PORT,
SVC_SOCK_DEFAULTS, cred);
if (error < 0)
return error;
return 0;
}
static int nfsd_users = 0;
static int nfsd_startup_generic(int nrservs)
{
int ret;
if (nfsd_users++)
return 0;
ret = nfsd_file_cache_init();
if (ret)
goto dec_users;
ret = nfs4_state_start();
if (ret)
goto out_file_cache;
return 0;
out_file_cache:
nfsd_file_cache_shutdown();
dec_users:
nfsd_users--;
return ret;
}
static void nfsd_shutdown_generic(void)
{
if (--nfsd_users)
return;
nfs4_state_shutdown();
nfsd_file_cache_shutdown();
}
static bool nfsd_needs_lockd(struct nfsd_net *nn)
{
return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST);
}
void nfsd_copy_boot_verifier(__be32 verf[2], struct nfsd_net *nn)
{
int seq = 0;
do {
read_seqbegin_or_lock(&nn->boot_lock, &seq);
/*
* This is opaque to client, so no need to byte-swap. Use
* __force to keep sparse happy. y2038 time_t overflow is
* irrelevant in this usage
*/
verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec;
verf[1] = (__force __be32)nn->nfssvc_boot.tv_nsec;
} while (need_seqretry(&nn->boot_lock, seq));
done_seqretry(&nn->boot_lock, seq);
}
static void nfsd_reset_boot_verifier_locked(struct nfsd_net *nn)
{
ktime_get_real_ts64(&nn->nfssvc_boot);
}
void nfsd_reset_boot_verifier(struct nfsd_net *nn)
{
write_seqlock(&nn->boot_lock);
nfsd_reset_boot_verifier_locked(nn);
write_sequnlock(&nn->boot_lock);
}
static int nfsd_startup_net(int nrservs, struct net *net, const struct cred *cred)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
int ret;
if (nn->nfsd_net_up)
return 0;
ret = nfsd_startup_generic(nrservs);
if (ret)
return ret;
ret = nfsd_init_socks(net, cred);
if (ret)
goto out_socks;
if (nfsd_needs_lockd(nn) && !nn->lockd_up) {
ret = lockd_up(net, cred);
if (ret)
goto out_socks;
nn->lockd_up = true;
}
ret = nfsd_file_cache_start_net(net);
if (ret)
goto out_lockd;
ret = nfs4_state_start_net(net);
if (ret)
goto out_filecache;
nn->nfsd_net_up = true;
return 0;
out_filecache:
nfsd_file_cache_shutdown_net(net);
out_lockd:
if (nn->lockd_up) {
lockd_down(net);
nn->lockd_up = false;
}
out_socks:
nfsd_shutdown_generic();
return ret;
}
static void nfsd_shutdown_net(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
nfsd_file_cache_shutdown_net(net);
nfs4_state_shutdown_net(net);
if (nn->lockd_up) {
lockd_down(net);
nn->lockd_up = false;
}
nn->nfsd_net_up = false;
nfsd_shutdown_generic();
}
static int nfsd_inetaddr_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
struct net_device *dev = ifa->ifa_dev->dev;
struct net *net = dev_net(dev);
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct sockaddr_in sin;
if ((event != NETDEV_DOWN) ||
!atomic_inc_not_zero(&nn->ntf_refcnt))
goto out;
if (nn->nfsd_serv) {
dprintk("nfsd_inetaddr_event: removed %pI4\n", &ifa->ifa_local);
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = ifa->ifa_local;
svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin);
}
atomic_dec(&nn->ntf_refcnt);
wake_up(&nn->ntf_wq);
out:
return NOTIFY_DONE;
}
static struct notifier_block nfsd_inetaddr_notifier = {
.notifier_call = nfsd_inetaddr_event,
};
#if IS_ENABLED(CONFIG_IPV6)
static int nfsd_inet6addr_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
struct net_device *dev = ifa->idev->dev;
struct net *net = dev_net(dev);
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct sockaddr_in6 sin6;
if ((event != NETDEV_DOWN) ||
!atomic_inc_not_zero(&nn->ntf_refcnt))
goto out;
if (nn->nfsd_serv) {
dprintk("nfsd_inet6addr_event: removed %pI6\n", &ifa->addr);
sin6.sin6_family = AF_INET6;
sin6.sin6_addr = ifa->addr;
if (ipv6_addr_type(&sin6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
sin6.sin6_scope_id = ifa->idev->dev->ifindex;
svc_age_temp_xprts_now(nn->nfsd_serv, (struct sockaddr *)&sin6);
}
atomic_dec(&nn->ntf_refcnt);
wake_up(&nn->ntf_wq);
out:
return NOTIFY_DONE;
}
static struct notifier_block nfsd_inet6addr_notifier = {
.notifier_call = nfsd_inet6addr_event,
};
#endif
/* Only used under nfsd_mutex, so this atomic may be overkill: */
static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
atomic_dec(&nn->ntf_refcnt);
/* check if the notifier still has clients */
if (atomic_dec_return(&nfsd_notifier_refcount) == 0) {
unregister_inetaddr_notifier(&nfsd_inetaddr_notifier);
#if IS_ENABLED(CONFIG_IPV6)
unregister_inet6addr_notifier(&nfsd_inet6addr_notifier);
#endif
}
wait_event(nn->ntf_wq, atomic_read(&nn->ntf_refcnt) == 0);
/*
* write_ports can create the server without actually starting
* any threads--if we get shut down before any threads are
* started, then nfsd_last_thread will be run before any of this
* other initialization has been done except the rpcb information.
*/
svc_rpcb_cleanup(serv, net);
if (!nn->nfsd_net_up)
return;
nfsd_shutdown_net(net);
printk(KERN_WARNING "nfsd: last server has exited, flushing export "
"cache\n");
nfsd_export_flush(net);
}
void nfsd_reset_versions(struct nfsd_net *nn)
{
int i;
for (i = 0; i < NFSD_NRVERS; i++)
if (nfsd_vers(nn, i, NFSD_TEST))
return;
for (i = 0; i < NFSD_NRVERS; i++)
if (i != 4)
nfsd_vers(nn, i, NFSD_SET);
else {
int minor = 0;
while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0)
minor++;
}
}
/*
* Each session guarantees a negotiated per slot memory cache for replies
* which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
* NFSv4.1 server might want to use more memory for a DRC than a machine
* with mutiple services.
*
* Impose a hard limit on the number of pages for the DRC which varies
* according to the machines free pages. This is of course only a default.
*
* For now this is a #defined shift which could be under admin control
* in the future.
*/
static void set_max_drc(void)
{
#define NFSD_DRC_SIZE_SHIFT 7
nfsd_drc_max_mem = (nr_free_buffer_pages()
>> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
nfsd_drc_mem_used = 0;
spin_lock_init(&nfsd_drc_lock);
dprintk("%s nfsd_drc_max_mem %lu \n", __func__, nfsd_drc_max_mem);
}
static int nfsd_get_default_max_blksize(void)
{
struct sysinfo i;
unsigned long long target;
unsigned long ret;
si_meminfo(&i);
target = (i.totalram - i.totalhigh) << PAGE_SHIFT;
/*
* 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.
*/
target >>= 12;
ret = NFSSVC_MAXBLKSIZE;
while (ret > target && ret >= 8*1024*2)
ret /= 2;
return ret;
}
static const struct svc_serv_ops nfsd_thread_sv_ops = {
.svo_shutdown = nfsd_last_thread,
.svo_function = nfsd,
.svo_enqueue_xprt = svc_xprt_do_enqueue,
.svo_setup = svc_set_num_threads,
.svo_module = THIS_MODULE,
};
bool i_am_nfsd(void)
{
return kthread_func(current) == nfsd;
}
int nfsd_create_serv(struct net *net)
{
int error;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
WARN_ON(!mutex_is_locked(&nfsd_mutex));
if (nn->nfsd_serv) {
svc_get(nn->nfsd_serv);
return 0;
}
if (nfsd_max_blksize == 0)
nfsd_max_blksize = nfsd_get_default_max_blksize();
nfsd_reset_versions(nn);
nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
&nfsd_thread_sv_ops);
if (nn->nfsd_serv == NULL)
return -ENOMEM;
nn->nfsd_serv->sv_maxconn = nn->max_connections;
error = svc_bind(nn->nfsd_serv, net);
if (error < 0) {
svc_destroy(nn->nfsd_serv);
return error;
}
set_max_drc();
/* check if the notifier is already set */
if (atomic_inc_return(&nfsd_notifier_refcount) == 1) {
register_inetaddr_notifier(&nfsd_inetaddr_notifier);
#if IS_ENABLED(CONFIG_IPV6)
register_inet6addr_notifier(&nfsd_inet6addr_notifier);
#endif
}
atomic_inc(&nn->ntf_refcnt);
nfsd_reset_boot_verifier(nn);
return 0;
}
int nfsd_nrpools(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (nn->nfsd_serv == NULL)
return 0;
else
return nn->nfsd_serv->sv_nrpools;
}
int nfsd_get_nrthreads(int n, int *nthreads, struct net *net)
{
int i = 0;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (nn->nfsd_serv != NULL) {
for (i = 0; i < nn->nfsd_serv->sv_nrpools && i < n; i++)
nthreads[i] = nn->nfsd_serv->sv_pools[i].sp_nrthreads;
}
return 0;
}
void nfsd_destroy(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
int destroy = (nn->nfsd_serv->sv_nrthreads == 1);
if (destroy)
svc_shutdown_net(nn->nfsd_serv, net);
svc_destroy(nn->nfsd_serv);
if (destroy)
nn->nfsd_serv = NULL;
}
int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)
{
int i = 0;
int tot = 0;
int err = 0;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
WARN_ON(!mutex_is_locked(&nfsd_mutex));
if (nn->nfsd_serv == NULL || n <= 0)
return 0;
if (n > nn->nfsd_serv->sv_nrpools)
n = nn->nfsd_serv->sv_nrpools;
/* enforce a global maximum number of threads */
tot = 0;
for (i = 0; i < n; i++) {
nthreads[i] = min(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 */
svc_get(nn->nfsd_serv);
for (i = 0; i < n; i++) {
err = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
&nn->nfsd_serv->sv_pools[i], nthreads[i]);
if (err)
break;
}
nfsd_destroy(net);
return err;
}
/*
* Adjust the number of threads and return the new number of threads.
* This is also the function that starts the server if necessary, if
* this is the first time nrservs is nonzero.
*/
int
nfsd_svc(int nrservs, struct net *net, const struct cred *cred)
{
int error;
bool nfsd_up_before;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
mutex_lock(&nfsd_mutex);
dprintk("nfsd: creating service\n");
nrservs = max(nrservs, 0);
nrservs = min(nrservs, NFSD_MAXSERVS);
error = 0;
if (nrservs == 0 && nn->nfsd_serv == NULL)
goto out;
strlcpy(nn->nfsd_name, utsname()->nodename,
sizeof(nn->nfsd_name));
error = nfsd_create_serv(net);
if (error)
goto out;
nfsd_up_before = nn->nfsd_net_up;
error = nfsd_startup_net(nrservs, net, cred);
if (error)
goto out_destroy;
error = nn->nfsd_serv->sv_ops->svo_setup(nn->nfsd_serv,
NULL, nrservs);
if (error)
goto out_shutdown;
/* We are holding a reference to nn->nfsd_serv which
* we don't want to count in the return value,
* so subtract 1
*/
error = nn->nfsd_serv->sv_nrthreads - 1;
out_shutdown:
if (error < 0 && !nfsd_up_before)
nfsd_shutdown_net(net);
out_destroy:
nfsd_destroy(net); /* Release server */
out:
mutex_unlock(&nfsd_mutex);
return error;
}
#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
static bool
nfsd_support_acl_version(int vers)
{
if (vers >= NFSD_ACL_MINVERS && vers < NFSD_ACL_NRVERS)
return nfsd_acl_version[vers] != NULL;
return false;
}
static int
nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp,
u32 version, int family, unsigned short proto,
unsigned short port)
{
if (!nfsd_support_acl_version(version) ||
!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
return 0;
return svc_generic_rpcbind_set(net, progp, version, family,
proto, port);
}
static __be32
nfsd_acl_init_request(struct svc_rqst *rqstp,
const struct svc_program *progp,
struct svc_process_info *ret)
{
struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
int i;
if (likely(nfsd_support_acl_version(rqstp->rq_vers) &&
nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
return svc_generic_init_request(rqstp, progp, ret);
ret->mismatch.lovers = NFSD_ACL_NRVERS;
for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
if (nfsd_support_acl_version(rqstp->rq_vers) &&
nfsd_vers(nn, i, NFSD_TEST)) {
ret->mismatch.lovers = i;
break;
}
}
if (ret->mismatch.lovers == NFSD_ACL_NRVERS)
return rpc_prog_unavail;
ret->mismatch.hivers = NFSD_ACL_MINVERS;
for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) {
if (nfsd_support_acl_version(rqstp->rq_vers) &&
nfsd_vers(nn, i, NFSD_TEST)) {
ret->mismatch.hivers = i;
break;
}
}
return rpc_prog_mismatch;
}
#endif
static int
nfsd_rpcbind_set(struct net *net, const struct svc_program *progp,
u32 version, int family, unsigned short proto,
unsigned short port)
{
if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
return 0;
return svc_generic_rpcbind_set(net, progp, version, family,
proto, port);
}
static __be32
nfsd_init_request(struct svc_rqst *rqstp,
const struct svc_program *progp,
struct svc_process_info *ret)
{
struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
int i;
if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
return svc_generic_init_request(rqstp, progp, ret);
ret->mismatch.lovers = NFSD_NRVERS;
for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
if (nfsd_vers(nn, i, NFSD_TEST)) {
ret->mismatch.lovers = i;
break;
}
}
if (ret->mismatch.lovers == NFSD_NRVERS)
return rpc_prog_unavail;
ret->mismatch.hivers = NFSD_MINVERS;
for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) {
if (nfsd_vers(nn, i, NFSD_TEST)) {
ret->mismatch.hivers = i;
break;
}
}
return rpc_prog_mismatch;
}
/*
* This is the NFS server kernel thread
*/
static int
nfsd(void *vrqstp)
{
struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
struct svc_xprt *perm_sock = list_entry(rqstp->rq_server->sv_permsocks.next, typeof(struct svc_xprt), xpt_list);
struct net *net = perm_sock->xpt_net;
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
int err;
/* Lock module and set up kernel thread */
mutex_lock(&nfsd_mutex);
/* At this point, the thread shares current->fs
* with the init process. We need to create files with the
* umask as defined by the client instead of init's umask. */
if (unshare_fs_struct() < 0) {
printk("Unable to start nfsd thread: out of memory\n");
goto out;
}
current->fs->umask = 0;
/*
* thread is spawned with all signals set to SIG_IGN, re-enable
* the ones that will bring down the thread
*/
allow_signal(SIGKILL);
allow_signal(SIGHUP);
allow_signal(SIGINT);
allow_signal(SIGQUIT);
nfsdstats.th_cnt++;
mutex_unlock(&nfsd_mutex);
set_freezable();
/*
* The main request loop
*/
for (;;) {
/* Update sv_maxconn if it has changed */
rqstp->rq_server->sv_maxconn = nn->max_connections;
/*
* Find a socket with data available and call its
* recvfrom routine.
*/
while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
;
if (err == -EINTR)
break;
validate_process_creds();
svc_process(rqstp);
validate_process_creds();
}
/* Clear signals before calling svc_exit_thread() */
flush_signals(current);
mutex_lock(&nfsd_mutex);
nfsdstats.th_cnt --;
out:
rqstp->rq_server = NULL;
/* Release the thread */
svc_exit_thread(rqstp);
nfsd_destroy(net);
/* Release module */
mutex_unlock(&nfsd_mutex);
module_put_and_exit(0);
return 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;
}
/*
* A write procedure can have a large argument, and a read procedure can
* have a large reply, but no NFSv2 or NFSv3 procedure has argument and
* reply that can both be larger than a page. The xdr code has taken
* advantage of this assumption to be a sloppy about bounds checking in
* some cases. Pending a rewrite of the NFSv2/v3 xdr code to fix that
* problem, we enforce these assumptions here:
*/
static bool nfs_request_too_big(struct svc_rqst *rqstp,
const struct svc_procedure *proc)
{
/*
* The ACL code has more careful bounds-checking and is not
* susceptible to this problem:
*/
if (rqstp->rq_prog != NFS_PROGRAM)
return false;
/*
* Ditto NFSv4 (which can in theory have argument and reply both
* more than a page):
*/
if (rqstp->rq_vers >= 4)
return false;
/* The reply will be small, we're OK: */
if (proc->pc_xdrressize > 0 &&
proc->pc_xdrressize < XDR_QUADLEN(PAGE_SIZE))
return false;
return rqstp->rq_arg.len > PAGE_SIZE;