diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 2edf716ea022..da6fce79efae 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -890,17 +890,31 @@ nfsd(void *vrqstp) { struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp; struct svc_pool *pool = rqstp->rq_pool; - 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); + struct svc_serv *serv = rqstp->rq_server; + struct svc_xprt *perm_sock; + struct net *net = NULL; + struct nfsd_net *nn = NULL; struct nfsd_thread_local_info ntli = { }; bool have_mutex = false; + int err = 0; + + spin_lock_bh(&serv->sv_lock); + if (list_empty(&serv->sv_permsocks)) { + err = -ENOTCONN; + } else { + perm_sock = list_first_entry(&serv->sv_permsocks, + struct svc_xprt, xpt_list); + net = perm_sock->xpt_net; + } + spin_unlock_bh(&serv->sv_lock); + if (!err) + nn = net_generic(net, nfsd_net_id); /* 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. */ - svc_thread_init_status(rqstp, unshare_fs_struct()); + svc_thread_init_status(rqstp, err ?: unshare_fs_struct()); current->fs->umask = 0; diff --git a/fs/nfsd/nfssvc.c.save b/fs/nfsd/nfssvc.c.save new file mode 100644 index 000000000000..1df1bc79aaef --- /dev/null +++ b/fs/nfsd/nfssvc.c.save @@ -0,0 +1,1107 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Central processing for nfsd. + * + * Authors: Olaf Kirch (okir@monad.swb.de) + * + * Copyright (C) 1995, 1996, 1997 Olaf Kirch + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "nfsd.h" +#include "cache.h" +#include "vfs.h" +#include "netns.h" +#include "filecache.h" + +#include "trace.h" + +#define NFSDDBG_FACILITY NFSDDBG_SVC + +atomic_t nfsd_th_cnt = ATOMIC_INIT(0); +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. + * + * 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); + +#if IS_ENABLED(CONFIG_NFS_LOCALIO) +static const struct svc_version *localio_versions[] = { + [1] = &localio_version1, +}; + +#define NFSD_LOCALIO_NRVERS ARRAY_SIZE(localio_versions) + +#endif /* CONFIG_NFS_LOCALIO */ + +#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) +static const struct svc_version *nfsd_acl_version[] = { +# if defined(CONFIG_NFSD_V2_ACL) + [2] = &nfsd_acl_version2, +# endif +# if defined(CONFIG_NFSD_V3_ACL) + [3] = &nfsd_acl_version3, +# endif +}; + +#define NFSD_ACL_MINVERS 2 +#define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version) + +#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ + +static const struct svc_version *nfsd_version[NFSD_MAXVERS+1] = { +#if defined(CONFIG_NFSD_V2) + [2] = &nfsd_version2, +#endif + [3] = &nfsd_version3, +#if defined(CONFIG_NFSD_V4) + [4] = &nfsd_version4, +#endif +}; + +struct svc_program nfsd_programs[] = { + { + .pg_prog = NFS_PROGRAM, /* program number */ + .pg_nvers = NFSD_MAXVERS+1, /* nr of entries in nfsd_version */ + .pg_vers = nfsd_version, /* version table */ + .pg_name = "nfsd", /* program name */ + .pg_class = "nfsd", /* authentication class */ + .pg_authenticate = svc_set_client, /* export authentication */ + .pg_init_request = nfsd_init_request, + .pg_rpcbind_set = nfsd_rpcbind_set, + }, +#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) + { + .pg_prog = NFS_ACL_PROGRAM, + .pg_nvers = NFSD_ACL_NRVERS, + .pg_vers = nfsd_acl_version, + .pg_name = "nfsacl", + .pg_class = "nfsd", + .pg_authenticate = svc_set_client, + .pg_init_request = nfsd_acl_init_request, + .pg_rpcbind_set = nfsd_acl_rpcbind_set, + }, +#endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ +#if IS_ENABLED(CONFIG_NFS_LOCALIO) + { + .pg_prog = NFS_LOCALIO_PROGRAM, + .pg_nvers = NFSD_LOCALIO_NRVERS, + .pg_vers = localio_versions, + .pg_name = "nfslocalio", + .pg_class = "nfsd", + .pg_authenticate = svc_set_client, + .pg_init_request = svc_generic_init_request, + .pg_rpcbind_set = svc_generic_rpcbind_set, + } +#endif /* CONFIG_NFS_LOCALIO */ +}; + +bool nfsd_support_version(int vers) +{ + if (vers >= NFSD_MINVERS && vers <= NFSD_MAXVERS) + return nfsd_version[vers] != NULL; + return false; +} + +int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change) +{ + if (vers < NFSD_MINVERS || vers > NFSD_MAXVERS) + return 0; + switch(change) { + case NFSD_SET: + nn->nfsd_versions[vers] = nfsd_support_version(vers); + break; + case NFSD_CLEAR: + nn->nfsd_versions[vers] = false; + break; + case NFSD_TEST: + return nn->nfsd_versions[vers]; + 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: + nfsd_vers(nn, 4, NFSD_SET); + nn->nfsd4_minorversions[minorversion] = + nfsd_vers(nn, 4, NFSD_TEST); + break; + case NFSD_CLEAR: + nn->nfsd4_minorversions[minorversion] = false; + nfsd_adjust_nfsd_versions4(nn); + break; + case NFSD_TEST: + return nn->nfsd4_minorversions[minorversion]; + case NFSD_AVAIL: + return minorversion <= NFSD_SUPPORTED_MINOR_VERSION && + nfsd_vers(nn, 4, NFSD_AVAIL); + } + return 0; +} + +bool nfsd_net_try_get(struct net *net) __must_hold(rcu) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + return (nn && percpu_ref_tryget_live(&nn->nfsd_net_ref)); +} + +void nfsd_net_put(struct net *net) __must_hold(rcu) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + percpu_ref_put(&nn->nfsd_net_ref); +} + +static void nfsd_net_done(struct percpu_ref *ref) +{ + struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_net_ref); + + complete(&nn->nfsd_net_confirm_done); +} + +static void nfsd_net_free(struct percpu_ref *ref) +{ + struct nfsd_net *nn = container_of(ref, struct nfsd_net, nfsd_net_ref); + + complete(&nn->nfsd_net_free_done); +} + +/* + * Maximum number of nfsd processes + */ +#define NFSD_MAXSERVS 8192 + +/** + * nfsd_nrthreads - report a namespace's configured nfsd thread count + * @net: network namespace to query + * + * Return: the configured thread ceiling, or 0 when no service runs. + */ +int nfsd_nrthreads(struct net *net) +{ + int rv = 0; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + /* nfsd_mutex keeps nn->nfsd_serv valid across the read. */ + mutex_lock(&nfsd_mutex); + if (nn->nfsd_serv) + rv = svc_serv_maxthreads(nn->nfsd_serv); + mutex_unlock(&nfsd_mutex); + return rv; +} + +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) +{ + unsigned int seq; + + do { + seq = read_seqbegin(&nn->writeverf_lock); + memcpy(verf, nn->writeverf, sizeof(nn->writeverf)); + } while (read_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); +} + +/* + * Crank up a set of per-namespace resources for a new NFSD instance, + * including lockd, a duplicate reply cache, an open file cache + * instance, and a cache of NFSv4 state objects. + */ +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 (test_bit(NFSD_NET_UP, &nn->flags)) + return 0; + + ret = nfsd_startup_generic(); + if (ret) + return ret; + + if (list_empty(&nn->nfsd_serv->sv_permsocks)) { + pr_warn("NFSD: Failed to start, no listeners configured.\n"); + ret = -EIO; + goto out_socks; + } + + if (nfsd_needs_lockd(nn) && !test_bit(NFSD_NET_LOCKD_UP, &nn->flags)) { + ret = lockd_up(net, cred); + if (ret) + goto out_socks; + set_bit(NFSD_NET_LOCKD_UP, &nn->flags); + } + + ret = nfsd_file_cache_start_net(net); + if (ret) + goto out_lockd; + + ret = nfsd_reply_cache_init(nn); + if (ret) + goto out_filecache; + +#ifdef CONFIG_NFSD_V4_2_INTER_SSC + nfsd4_ssc_init_umount_work(nn); +#endif + ret = nfs4_state_start_net(net); + if (ret) + goto out_reply_cache; + + set_bit(NFSD_NET_UP, &nn->flags); + return 0; + +out_reply_cache: + nfsd_reply_cache_shutdown(nn); +out_filecache: + nfsd_file_cache_shutdown_net(net); +out_lockd: + if (test_bit(NFSD_NET_LOCKD_UP, &nn->flags)) { + lockd_down(net); + clear_bit(NFSD_NET_LOCKD_UP, &nn->flags); + } +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); + + if (test_bit(NFSD_NET_UP, &nn->flags)) { + percpu_ref_kill_and_confirm(&nn->nfsd_net_ref, nfsd_net_done); + wait_for_completion(&nn->nfsd_net_confirm_done); + + nfsd_export_flush(net); + nfs4_state_shutdown_net(net); + nfsd_reply_cache_shutdown(nn); + nfsd_file_cache_shutdown_net(net); + if (test_bit(NFSD_NET_LOCKD_UP, &nn->flags)) { + lockd_down(net); + clear_bit(NFSD_NET_LOCKD_UP, &nn->flags); + } + wait_for_completion(&nn->nfsd_net_free_done); + } + + percpu_ref_exit(&nn->nfsd_net_ref); + + if (test_bit(NFSD_NET_UP, &nn->flags)) + nfsd_shutdown_generic(); + clear_bit(NFSD_NET_UP, &nn->flags); +} + +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); + +/** + * nfsd_destroy_serv - tear down NFSD's svc_serv for a namespace + * @net: network namespace the NFS service is associated with + */ +void nfsd_destroy_serv(struct net *net) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct svc_serv *serv = nn->nfsd_serv; + + lockdep_assert_held(&nfsd_mutex); + + spin_lock(&nfsd_notifier_lock); + nn->nfsd_serv = NULL; + spin_unlock(&nfsd_notifier_lock); + + /* 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_destroy_serv will be run before any of this + * other initialization has been done except the rpcb information. + */ + svc_xprt_destroy_all(serv, net, true); + nfsd_shutdown_net(net); + svc_destroy(&serv); +} + +void nfsd_reset_versions(struct nfsd_net *nn) +{ + int i; + + for (i = 0; i <= NFSD_MAXVERS; i++) + if (nfsd_vers(nn, i, NFSD_TEST)) + return; + + for (i = 0; i <= NFSD_MAXVERS; i++) + if (i != 4) + nfsd_vers(nn, i, NFSD_SET); + else { + int minor = 0; + while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0) + minor++; + } +} + +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_DEFBLKSIZE; + 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; + } + + /* Kill outstanding nfsd threads */ + svc_set_num_threads(serv, 0, 0); + nfsd_destroy_serv(net); + mutex_unlock(&nfsd_mutex); +} + +struct svc_rqst *nfsd_current_rqst(void) +{ + if (kthread_func(current) == nfsd) + return kthread_data(current); + return NULL; +} + +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) + return 0; + + error = percpu_ref_init(&nn->nfsd_net_ref, nfsd_net_free, + 0, GFP_KERNEL); + if (error) + return error; + init_completion(&nn->nfsd_net_free_done); + init_completion(&nn->nfsd_net_confirm_done); + + if (nfsd_max_blksize == 0) + nfsd_max_blksize = nfsd_get_default_max_blksize(); + nfsd_reset_versions(nn); + serv = svc_create_pooled(nfsd_programs, ARRAY_SIZE(nfsd_programs), + &nn->nfsd_svcstats, + nfsd_max_blksize, nfsd); + if (serv == NULL) { + percpu_ref_exit(&nn->nfsd_net_ref); + return -ENOMEM; + } + + error = svc_bind(serv, net); + if (error < 0) { + svc_destroy(&serv); + percpu_ref_exit(&nn->nfsd_net_ref); + return error; + } + spin_lock(&nfsd_notifier_lock); + nn->nfsd_serv = serv; + spin_unlock(&nfsd_notifier_lock); + + /* 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 svc_serv_nrpools(nn->nfsd_serv); +} + +int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct svc_serv *serv = nn->nfsd_serv; + int i; + + if (serv) + for (i = 0; i < svc_serv_nrpools(serv) && i < n; i++) + nthreads[i] = serv->sv_pools[i].sp_nrthrmax; + return 0; +} + +/** + * nfsd_set_nrthreads - set the number of running threads in the net's service + * @n: number of array members in @nthreads + * @nthreads: array of thread counts for each pool + * @net: network namespace to operate within + * + * This function alters the number of running threads for the given network + * namespace in each pool. If passed an array longer then the number of pools + * the extra pool settings are ignored. If passed an array shorter than the + * number of pools, the missing values are interpreted as 0's. + * + * Returns 0 on success or a negative errno on error. + */ +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); + + lockdep_assert_held(&nfsd_mutex); + + if (nn->nfsd_serv == NULL || n <= 0) + return 0; + + /* Special case: When n == 1, distribute threads equally among pools. */ + if (n == 1) + return svc_set_num_threads(nn->nfsd_serv, nn->min_threads, nthreads[0]); + + if (n > svc_serv_nrpools(nn->nfsd_serv)) + n = svc_serv_nrpools(nn->nfsd_serv); + + /* 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--; + } + } + + /* apply the new numbers */ + for (i = 0; i < n; i++) { + err = svc_set_pool_threads(nn->nfsd_serv, + &nn->nfsd_serv->sv_pools[i], + nn->min_threads, nthreads[i]); + if (err) + goto out; + } + + /* Anything undefined in array is considered to be 0 */ + for (i = n; i < svc_serv_nrpools(nn->nfsd_serv); ++i) { + err = svc_set_pool_threads(nn->nfsd_serv, + &nn->nfsd_serv->sv_pools[i], + 0, 0); + if (err) + goto out; + } +out: + return err; +} + +/** + * nfsd_svc: start up or shut down the nfsd server + * @n: number of array members in @nthreads + * @nthreads: array of thread counts for each pool + * @net: network namespace to operate within + * @cred: credentials to use for xprt creation + * @scope: server scope value (defaults to nodename) + * + * Adjust the number of threads in each pool and return the new + * total number of threads in the service. + */ +int +nfsd_svc(int n, int *nthreads, struct net *net, const struct cred *cred, const char *scope) +{ + int error; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct svc_serv *serv; + + lockdep_assert_held(&nfsd_mutex); + + dprintk("nfsd: creating service\n"); + + strscpy(nn->nfsd_name, scope ? scope : utsname()->nodename, + sizeof(nn->nfsd_name)); + + error = nfsd_create_serv(net); + if (error) + goto out; + serv = nn->nfsd_serv; + + error = nfsd_startup_net(net, cred); + if (error) + goto out_put; + error = nfsd_set_nrthreads(n, nthreads, net); + if (error) + goto out_put; + error = serv->sv_nrthreads; +out_put: + if (serv->sv_nrthreads == 0) + nfsd_destroy_serv(net); +out: + 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(i) && + 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(i) && + 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_MAXVERS + 1; + for (i = NFSD_MINVERS; i <= NFSD_MAXVERS; i++) { + if (nfsd_vers(nn, i, NFSD_TEST)) { + ret->mismatch.lovers = i; + break; + } + } + if (ret->mismatch.lovers > NFSD_MAXVERS) + return rpc_prog_unavail; + ret->mismatch.hivers = NFSD_MINVERS; + for (i = NFSD_MAXVERS; 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_pool *pool = rqstp->rq_pool; + struct svc_xprt *perm_sock; + struct net *net; + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct nfsd_thread_local_info ntli = { }; + bool have_mutex = false; + + spin_lock_bh(&serv->sv_lock); + if (list_empty(&serv->sv_permsocks)) { + err = -ENOTCONN; + } else { + perm_sock = list_first_entry(&serv->sv_permsocks, + struct svc_xprt, xpt_list); + net = perm_sock->xpt_net; + } + spin_unlock_bh(&serv->sv_lock); + + + + /* 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. + */ + svc_thread_init_status(rqstp, unshare_fs_struct()); + + current->fs->umask = 0; + + atomic_inc(&nfsd_th_cnt); + + set_freezable(); + + /* use dynamic allocation if ntli should ever become large */ + static_assert(sizeof(struct nfsd_thread_local_info) < 256); + rqstp->rq_private = &ntli; + + /* + * The main request loop + */ + while (!svc_thread_should_stop(rqstp)) { + switch (svc_recv(rqstp, 5 * HZ)) { + case -ETIMEDOUT: + /* No work arrived within the timeout window */ + if (mutex_trylock(&nfsd_mutex)) { + if (pool->sp_nrthreads > pool->sp_nrthrmin) { + trace_nfsd_dynthread_kill(net, pool); + set_bit(RQ_VICTIM, &rqstp->rq_flags); + have_mutex = true; + } else { + mutex_unlock(&nfsd_mutex); + } + } else { + trace_nfsd_dynthread_trylock_fail(net, pool); + } + break; + case -EBUSY: + /* No idle threads; consider spawning another */ + if (pool->sp_nrthreads < pool->sp_nrthrmax) { + if (mutex_trylock(&nfsd_mutex)) { + if (pool->sp_nrthreads < pool->sp_nrthrmax) { + int ret; + + trace_nfsd_dynthread_start(net, pool); + ret = svc_new_thread(rqstp->rq_server, pool); + if (ret) + pr_notice_ratelimited("%s: unable to spawn new thread: %d\n", + __func__, ret); + } + mutex_unlock(&nfsd_mutex); + } else { + trace_nfsd_dynthread_trylock_fail(net, pool); + } + } + clear_bit(SP_TASK_STARTING, &pool->sp_flags); + break; + default: + break; + } + nfsd_file_net_dispose(nn); + } + + atomic_dec(&nfsd_th_cnt); + + /* Release the thread */ + svc_exit_thread(rqstp); + if (have_mutex) + mutex_unlock(&nfsd_mutex); + return 0; +} + +/* + * Set rq_status_counter back to an even value, indicating that the rqstp + * fields are no longer meaningful to a lockless reader. This pairs with the + * odd-valued store made once the request has been decoded, and must run on + * every return path that follows it so that the seq-lock like protocol used + * by nfsd_nl_rpc_status_get_dumpit() is not left permanently odd. The store + * also advances the counter so a concurrent reader detects the transition. + */ +static void nfsd_status_counter_set_idle(struct svc_rqst *rqstp) +{ + smp_store_release(&rqstp->rq_status_counter, + (rqstp->rq_status_counter | 1) + 1); +} + +/** + * nfsd_dispatch - Process an NFS or NFSACL or LOCALIO Request + * @rqstp: incoming request + * + * 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) +{ + struct nfsd_thread_local_info *ntli = rqstp->rq_private; + const struct svc_procedure *proc = rqstp->rq_procinfo; + __be32 *statp = rqstp->rq_accept_statp; + struct nfsd_cacherep *rp; + 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) + */ + ntli->ntli_cachetype = proc->pc_cachetype; + + /* + * ->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; + + /* + * Release rq_status_counter setting it to an odd value after the rpc + * request has been properly parsed. rq_status_counter is used to + * notify the consumers if the rqstp fields are stable + * (rq_status_counter is odd) or not meaningful (rq_status_counter + * is even). + */ + smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1); + + rp = NULL; + switch (nfsd_cache_lookup(rqstp, start, len, &rp)) { + case RC_DOIT: + break; + case RC_REPLY: + goto out_cached_reply; + case RC_DROPIT: + goto out_dropit; + } + + nfs_reply = xdr_inline_decode(&rqstp->rq_res_stream, 0); + *statp = proc->pc_func(rqstp); + if (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, rp, ntli->ntli_cachetype, nfs_reply); +out_cached_reply: + nfsd_status_counter_set_idle(rqstp); + return 1; + +out_decode_err: + trace_nfsd_garbage_args_err(rqstp); + *statp = rpc_garbage_args; + return 1; + +out_update_drop: + nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); +out_dropit: + nfsd_status_counter_set_idle(rqstp); + return 0; + +out_encode_err: + trace_nfsd_cant_encode_err(rqstp); + nfsd_cache_update(rqstp, rp, RC_NOCACHE, NULL); + *statp = rpc_system_err; + nfsd_status_counter_set_idle(rqstp); + 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; +}