linux/fs/nfsd/nfssvc.c
Dai Ngo f4e44b3933 NFSD: delay unmount source's export after inter-server copy completed.
Currently the source's export is mounted and unmounted on every
inter-server copy operation. This patch is an enhancement to delay
the unmount of the source export for a certain period of time to
eliminate the mount and unmount overhead on subsequent copy operations.

After a copy operation completes, a work entry is added to the
delayed unmount list with an expiration time. This list is serviced
by the laundromat thread to unmount the export of the expired entries.
Each time the export is being used again, its expiration time is
extended and the entry is re-inserted to the tail of the list.

The unmount task and the mount operation of the copy request are
synced to make sure the export is not unmounted while it's being
used.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-05-25 17:06:51 -04:00

1121 lines
27 KiB
C

// 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"
#include "trace.h"
#define NFSDDBG_FACILITY NFSDDBG_SVC
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.
*/
DEFINE_SPINLOCK(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(void)
{
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(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();
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;
#ifdef CONFIG_NFSD_V4_2_INTER_SSC
nfsd4_ssc_init_umount_work(nn);
#endif
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);
pr_info("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;
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,
};
static void nfsd_complete_shutdown(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
WARN_ON(!mutex_is_locked(&nfsd_mutex));
nn->nfsd_serv = NULL;
complete(&nn->nfsd_shutdown_complete);
}
void nfsd_shutdown_threads(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
struct svc_serv *serv;
mutex_lock(&nfsd_mutex);
serv = nn->nfsd_serv;
if (serv == NULL) {
mutex_unlock(&nfsd_mutex);
return;
}
svc_get(serv);
/* Kill outstanding nfsd threads */
serv->sv_ops->svo_setup(serv, NULL, 0);
nfsd_destroy(net);
mutex_unlock(&nfsd_mutex);
/* Wait for shutdown of nfsd_serv to complete */
wait_for_completion(&nn->nfsd_shutdown_complete);
}
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;
init_completion(&nn->nfsd_shutdown_complete);
nn->nfsd_serv->sv_maxconn = nn->max_connections;
error = svc_bind(nn->nfsd_serv, net);
if (error < 0) {
svc_destroy(nn->nfsd_serv);
nfsd_complete_shutdown(net);
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)
nfsd_complete_shutdown(net);
}
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(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;
}
/**
* nfsd_dispatch - Process an NFS or NFSACL Request
* @rqstp: incoming request
* @statp: pointer to location of accept_stat field in RPC Reply buffer
*
* This RPC dispatcher integrates the NFS server's duplicate reply cache.
*
* Return values:
* %0: Processing complete; do not send a Reply
* %1: Processing complete; send Reply in rqstp->rq_res
*/
int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
{
const struct svc_procedure *proc = rqstp->rq_procinfo;
struct kvec *argv = &rqstp->rq_arg.head[0];
struct kvec *resv = &rqstp->rq_res.head[0];
__be32 *p;
/*
* Give the xdr decoder a chance to change this if it wants
* (necessary in the NFSv4.0 compound case)
*/
rqstp->rq_cachetype = proc->pc_cachetype;
svcxdr_init_decode(rqstp);
if (!proc->pc_decode(rqstp, argv->iov_base))
goto out_decode_err;
switch (nfsd_cache_lookup(rqstp)) {
case RC_DOIT:
break;
case RC_REPLY:
goto out_cached_reply;
case RC_DROPIT:
goto out_dropit;
}
/*
* Need to grab the location to store the status, as
* NFSv4 does some encoding while processing
*/
p = resv->iov_base + resv->iov_len;
svcxdr_init_encode(rqstp);
*statp = proc->pc_func(rqstp);
if (*statp == rpc_drop_reply || test_bit(RQ_DROPME, &rqstp->rq_flags))
goto out_update_drop;
if (!proc->pc_encode(rqstp, p))
goto out_encode_err;
nfsd_cache_update(rqstp, rqstp->rq_cachetype, statp + 1);
out_cached_reply:
return 1;
out_decode_err:
trace_nfsd_garbage_args_err(rqstp);
*statp = rpc_garbage_args;
return 1;
out_update_drop:
nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
out_dropit:
return 0;
out_encode_err:
trace_nfsd_cant_encode_err(rqstp);
nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
*statp = rpc_system_err;
return 1;
}
/**
* nfssvc_decode_voidarg - Decode void arguments
* @rqstp: Server RPC transaction context
* @p: buffer containing arguments to decode
*
* Return values:
* %0: Arguments were not valid
* %1: Decoding was successful
*/
int nfssvc_decode_voidarg(struct svc_rqst *rqstp, __be32 *p)
{
return 1;
}
/**
* nfssvc_encode_voidres - Encode void results
* @rqstp: Server RPC transaction context
* @p: buffer in which to encode results
*
* Return values:
* %0: Local error while encoding
* %1: Encoding was successful
*/
int nfssvc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
{
return 1;
}
int nfsd_pool_stats_open(struct inode *inode, struct file *file)
{
int ret;
struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id);
mutex_lock(&nfsd_mutex);
if (nn->nfsd_serv == NULL) {
mutex_unlock(&nfsd_mutex);
return -ENODEV;
}
/* bump up the psudo refcount while traversing */
svc_get(nn->nfsd_serv);
ret = svc_pool_stats_open(nn->nfsd_serv, file);
mutex_unlock(&nfsd_mutex);
return ret;
}
int nfsd_pool_stats_release(struct inode *inode, struct file *file)
{
int ret = seq_release(inode, file);
struct net *net = inode->i_sb->s_fs_info;
mutex_lock(&nfsd_mutex);
/* this function really, really should have been called svc_put() */
nfsd_destroy(net);
mutex_unlock(&nfsd_mutex);
return ret;
}