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Diffstat (limited to '')
| -rw-r--r-- | fs/nfsd/nfssvc.c | 1149 |
1 files changed, 1149 insertions, 0 deletions
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c new file mode 100644 index 000000000..c7695ebd2 --- /dev/null +++ b/fs/nfsd/nfssvc.c @@ -0,0 +1,1149 @@ +// 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, + [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; + + 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(nn->writeverf)); + } 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); + + nfs4_state_shutdown_net(net); + nfsd_file_cache_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); + 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; + + strscpy(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); + } + + 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; + unsigned int start, len; + __be32 *nfs_reply; + + /* + * 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); + + /* + * ->pc_decode advances the argument stream past the NFS + * Call header, so grab the header's starting location and + * size now for the call to nfsd_cache_lookup(). + */ + start = xdr_stream_pos(&rqstp->rq_arg_stream); + len = xdr_stream_remaining(&rqstp->rq_arg_stream); + if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) + goto out_decode_err; + + switch (nfsd_cache_lookup(rqstp, start, len)) { + 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); + + nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0); + *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, nfs_reply); +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) +{ + struct seq_file *seq = file->private_data; + struct svc_serv *serv = seq->private; + int ret = seq_release(inode, file); + + mutex_lock(&nfsd_mutex); + svc_put(serv); + mutex_unlock(&nfsd_mutex); + return ret; +} |