OpenCloudOS-Kernel/fs/nfsd/nfssvc.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
// 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"
2019-08-19 02:18:48 +08:00
#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,
[3] = &nfsd_version3,
#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_xprt_create(nn->nfsd_serv, "udp", net, PF_INET, NFS_PORT,
SVC_SOCK_DEFAULTS, cred);
if (error < 0)
return error;
error = svc_xprt_create(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;
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ret = nfsd_file_cache_init();
if (ret)
goto dec_users;
ret = nfs4_state_start();
if (ret)
goto out_file_cache;
return 0;
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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();
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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;
}
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);
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_xprt_destroy_all(nn->nfsd_serv, net);
nfsd_last_thread(nn->nfsd_serv, net);
svc_destroy(&nn->nfsd_serv->sv_refcnt);
spin_lock(&nfsd_notifier_lock);
NFSD: Make it possible to use svc_set_num_threads_sync nfsd cannot currently use svc_set_num_threads_sync. It instead uses svc_set_num_threads which does *not* wait for threads to all exit, and has a separate mechanism (nfsd_shutdown_complete) to wait for completion. The reason that nfsd is unlike other services is that nfsd threads can exit separately from svc_set_num_threads being called - they die on receipt of SIGKILL. Also, when the last thread exits, the service must be shut down (sockets closed). For this, the nfsd_mutex needs to be taken, and as that mutex needs to be held while svc_set_num_threads is called, the one cannot wait for the other. This patch changes the nfsd thread so that it can drop the ref on the service without blocking on nfsd_mutex, so that svc_set_num_threads_sync can be used: - if it can drop a non-last reference, it does that. This does not trigger shutdown and does not require a mutex. This will likely happen for all but the last thread signalled, and for all threads being shut down by nfsd_shutdown_threads() - if it can get the mutex without blocking (trylock), it does that and then drops the reference. This will likely happen for the last thread killed by SIGKILL - Otherwise there might be an unrelated task holding the mutex, possibly in another network namespace, or nfsd_shutdown_threads() might be just about to get a reference on the service, after which we can drop ours safely. We cannot conveniently get wakeup notifications on these events, and we are unlikely to need to, so we sleep briefly and check again. With this we can discard nfsd_shutdown_complete and nfsd_complete_shutdown(), and switch to svc_set_num_threads_sync. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-11-29 12:51:25 +08:00
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++) {
NFSD: Make it possible to use svc_set_num_threads_sync nfsd cannot currently use svc_set_num_threads_sync. It instead uses svc_set_num_threads which does *not* wait for threads to all exit, and has a separate mechanism (nfsd_shutdown_complete) to wait for completion. The reason that nfsd is unlike other services is that nfsd threads can exit separately from svc_set_num_threads being called - they die on receipt of SIGKILL. Also, when the last thread exits, the service must be shut down (sockets closed). For this, the nfsd_mutex needs to be taken, and as that mutex needs to be held while svc_set_num_threads is called, the one cannot wait for the other. This patch changes the nfsd thread so that it can drop the ref on the service without blocking on nfsd_mutex, so that svc_set_num_threads_sync can be used: - if it can drop a non-last reference, it does that. This does not trigger shutdown and does not require a mutex. This will likely happen for all but the last thread signalled, and for all threads being shut down by nfsd_shutdown_threads() - if it can get the mutex without blocking (trylock), it does that and then drops the reference. This will likely happen for the last thread killed by SIGKILL - Otherwise there might be an unrelated task holding the mutex, possibly in another network namespace, or nfsd_shutdown_threads() might be just about to get a reference on the service, after which we can drop ours safely. We cannot conveniently get wakeup notifications on these events, and we are unlikely to need to, so we sleep briefly and check again. With this we can discard nfsd_shutdown_complete and nfsd_complete_shutdown(), and switch to svc_set_num_threads_sync. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-11-29 12:51:25 +08:00
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);
NFSD: Make it possible to use svc_set_num_threads_sync nfsd cannot currently use svc_set_num_threads_sync. It instead uses svc_set_num_threads which does *not* wait for threads to all exit, and has a separate mechanism (nfsd_shutdown_complete) to wait for completion. The reason that nfsd is unlike other services is that nfsd threads can exit separately from svc_set_num_threads being called - they die on receipt of SIGKILL. Also, when the last thread exits, the service must be shut down (sockets closed). For this, the nfsd_mutex needs to be taken, and as that mutex needs to be held while svc_set_num_threads is called, the one cannot wait for the other. This patch changes the nfsd thread so that it can drop the ref on the service without blocking on nfsd_mutex, so that svc_set_num_threads_sync can be used: - if it can drop a non-last reference, it does that. This does not trigger shutdown and does not require a mutex. This will likely happen for all but the last thread signalled, and for all threads being shut down by nfsd_shutdown_threads() - if it can get the mutex without blocking (trylock), it does that and then drops the reference. This will likely happen for the last thread killed by SIGKILL - Otherwise there might be an unrelated task holding the mutex, possibly in another network namespace, or nfsd_shutdown_threads() might be just about to get a reference on the service, after which we can drop ours safely. We cannot conveniently get wakeup notifications on these events, and we are unlikely to need to, so we sleep briefly and check again. With this we can discard nfsd_shutdown_complete and nfsd_complete_shutdown(), and switch to svc_set_num_threads_sync. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-11-29 12:51:25 +08:00
/* 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);
}
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;
}