linux/fs/nfsd/nfssvc.c
Linus Torvalds 35ce8ae9ae Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull signal/exit/ptrace updates from Eric Biederman:
 "This set of changes deletes some dead code, makes a lot of cleanups
  which hopefully make the code easier to follow, and fixes bugs found
  along the way.

  The end-game which I have not yet reached yet is for fatal signals
  that generate coredumps to be short-circuit deliverable from
  complete_signal, for force_siginfo_to_task not to require changing
  userspace configured signal delivery state, and for the ptrace stops
  to always happen in locations where we can guarantee on all
  architectures that the all of the registers are saved and available on
  the stack.

  Removal of profile_task_ext, profile_munmap, and profile_handoff_task
  are the big successes for dead code removal this round.

  A bunch of small bug fixes are included, as most of the issues
  reported were small enough that they would not affect bisection so I
  simply added the fixes and did not fold the fixes into the changes
  they were fixing.

  There was a bug that broke coredumps piped to systemd-coredump. I
  dropped the change that caused that bug and replaced it entirely with
  something much more restrained. Unfortunately that required some
  rebasing.

  Some successes after this set of changes: There are few enough calls
  to do_exit to audit in a reasonable amount of time. The lifetime of
  struct kthread now matches the lifetime of struct task, and the
  pointer to struct kthread is no longer stored in set_child_tid. The
  flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is
  removed. Issues where task->exit_code was examined with
  signal->group_exit_code should been examined were fixed.

  There are several loosely related changes included because I am
  cleaning up and if I don't include them they will probably get lost.

  The original postings of these changes can be found at:
     https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org

  I trimmed back the last set of changes to only the obviously correct
  once. Simply because there was less time for review than I had hoped"

* 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits)
  ptrace/m68k: Stop open coding ptrace_report_syscall
  ptrace: Remove unused regs argument from ptrace_report_syscall
  ptrace: Remove second setting of PT_SEIZED in ptrace_attach
  taskstats: Cleanup the use of task->exit_code
  exit: Use the correct exit_code in /proc/<pid>/stat
  exit: Fix the exit_code for wait_task_zombie
  exit: Coredumps reach do_group_exit
  exit: Remove profile_handoff_task
  exit: Remove profile_task_exit & profile_munmap
  signal: clean up kernel-doc comments
  signal: Remove the helper signal_group_exit
  signal: Rename group_exit_task group_exec_task
  coredump: Stop setting signal->group_exit_task
  signal: Remove SIGNAL_GROUP_COREDUMP
  signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
  signal: Make coredump handling explicit in complete_signal
  signal: Have prepare_signal detect coredumps using signal->core_state
  signal: Have the oom killer detect coredumps using signal->core_state
  exit: Move force_uaccess back into do_exit
  exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
  ...
2022-01-17 05:49:30 +02:00

1149 lines
28 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/siphash.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 some members
* of the svc_serv struct such as ->sv_temp_socks and ->sv_permsocks.
*
* 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 (unless
* nn->keep_active is set). That number of nfsd threads must
* exist and each must be listed in ->sp_all_threads in some entry of
* ->sv_pools[].
*
* Each active thread holds a counted reference on nn->nfsd_serv, as does
* the nn->keep_active flag and various transient calls to svc_get().
*
* 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);
}
/**
* nfsd_copy_write_verifier - Atomically copy a write verifier
* @verf: buffer in which to receive the verifier cookie
* @nn: NFS net namespace
*
* This function provides a wait-free mechanism for copying the
* namespace's write verifier without tearing it.
*/
void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn)
{
int seq = 0;
do {
read_seqbegin_or_lock(&nn->writeverf_lock, &seq);
memcpy(verf, nn->writeverf, sizeof(*verf));
} while (need_seqretry(&nn->writeverf_lock, seq));
done_seqretry(&nn->writeverf_lock, seq);
}
static void nfsd_reset_write_verifier_locked(struct nfsd_net *nn)
{
struct timespec64 now;
u64 verf;
/*
* Because the time value is hashed, y2038 time_t overflow
* is irrelevant in this usage.
*/
ktime_get_raw_ts64(&now);
verf = siphash_2u64(now.tv_sec, now.tv_nsec, &nn->siphash_key);
memcpy(nn->writeverf, &verf, sizeof(nn->writeverf));
}
/**
* nfsd_reset_write_verifier - Generate a new write verifier
* @nn: NFS net namespace
*
* This function updates the ->writeverf field of @nn. This field
* contains an opaque cookie that, according to Section 18.32.3 of
* RFC 8881, "the client can use to determine whether a server has
* changed instance state (e.g., server restart) between a call to
* WRITE and a subsequent call to either WRITE or COMMIT. This
* cookie MUST be unchanged during a single instance of the NFSv4.1
* server and MUST be unique between instances of the NFSv4.1
* server."
*/
void nfsd_reset_write_verifier(struct nfsd_net *nn)
{
write_seqlock(&nn->writeverf_lock);
nfsd_reset_write_verifier_locked(nn);
write_sequnlock(&nn->writeverf_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 DEFINE_SPINLOCK(nfsd_notifier_lock);
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 || !nn->nfsd_serv)
goto out;
spin_lock(&nfsd_notifier_lock);
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);
}
spin_unlock(&nfsd_notifier_lock);
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 || !nn->nfsd_serv)
goto out;
spin_lock(&nfsd_notifier_lock);
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);
}
spin_unlock(&nfsd_notifier_lock);
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);
/* 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
}
/*
* 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_module = THIS_MODULE,
};
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 */
svc_set_num_threads(serv, NULL, 0);
nfsd_put(net);
mutex_unlock(&nfsd_mutex);
}
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);
struct svc_serv *serv;
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);
serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
&nfsd_thread_sv_ops);
if (serv == NULL)
return -ENOMEM;
serv->sv_maxconn = nn->max_connections;
error = svc_bind(serv, net);
if (error < 0) {
/* NOT nfsd_put() as notifiers (see below) haven't
* been set up yet.
*/
svc_put(serv);
return error;
}
spin_lock(&nfsd_notifier_lock);
nn->nfsd_serv = serv;
spin_unlock(&nfsd_notifier_lock);
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
}
nfsd_reset_write_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;
}
/* This is the callback for kref_put() below.
* There is no code here as the first thing to be done is
* call svc_shutdown_net(), but we cannot get the 'net' from
* the kref. So do all the work when kref_put returns true.
*/
static void nfsd_noop(struct kref *ref)
{
}
void nfsd_put(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
if (kref_put(&nn->nfsd_serv->sv_refcnt, nfsd_noop)) {
svc_shutdown_net(nn->nfsd_serv, net);
svc_destroy(&nn->nfsd_serv->sv_refcnt);
spin_lock(&nfsd_notifier_lock);
nn->nfsd_serv = NULL;
spin_unlock(&nfsd_notifier_lock);
}
}
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 = svc_set_num_threads(nn->nfsd_serv,
&nn->nfsd_serv->sv_pools[i],
nthreads[i]);
if (err)
break;
}
nfsd_put(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_put;
error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs);
if (error)
goto out_shutdown;
error = nn->nfsd_serv->sv_nrthreads;
out_shutdown:
if (error < 0 && !nfsd_up_before)
nfsd_shutdown_net(net);
out_put:
/* Threads now hold service active */
if (xchg(&nn->keep_active, 0))
nfsd_put(net);
nfsd_put(net);
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;
/* 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);
atomic_inc(&nfsdstats.th_cnt);
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);
atomic_dec(&nfsdstats.th_cnt);
out:
/* Take an extra ref so that the svc_put in svc_exit_thread()
* doesn't call svc_destroy()
*/
svc_get(nn->nfsd_serv);
/* Release the thread */
svc_exit_thread(rqstp);
/* We need to drop a ref, but may not drop the last reference
* without holding nfsd_mutex, and we cannot wait for nfsd_mutex as that
* could deadlock with nfsd_shutdown_threads() waiting for us.
* So three options are:
* - drop a non-final reference,
* - get the mutex without waiting
* - sleep briefly andd try the above again
*/
while (!svc_put_not_last(nn->nfsd_serv)) {
if (mutex_trylock(&nfsd_mutex)) {
nfsd_put(net);
mutex_unlock(&nfsd_mutex);
break;
}
msleep(20);
}
/* Release module */
module_put_and_kthread_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;
/*
* 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, &rqstp->rq_arg_stream))
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
*/
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, &rqstp->rq_res_stream))
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
* @xdr: XDR stream positioned at arguments to decode
*
* Return values:
* %false: Arguments were not valid
* %true: Decoding was successful
*/
bool nfssvc_decode_voidarg(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
return true;
}
/**
* nfssvc_encode_voidres - Encode void results
* @rqstp: Server RPC transaction context
* @xdr: XDR stream into which to encode results
*
* Return values:
* %false: Local error while encoding
* %true: Encoding was successful
*/
bool nfssvc_encode_voidres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
return true;
}
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;
}
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);
nfsd_put(net);
mutex_unlock(&nfsd_mutex);
return ret;
}