/* * linux/fs/lockd/svc.c * * This is the central lockd service. * * FIXME: Separate the lockd NFS server functionality from the lockd NFS * client functionality. Oh why didn't Sun create two separate * services in the first place? * * Authors: Olaf Kirch (okir@monad.swb.de) * * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */ #include <linux/module.h> #include <linux/init.h> #include <linux/sysctl.h> #include <linux/moduleparam.h> #include <linux/sched.h> #include <linux/errno.h> #include <linux/in.h> #include <linux/uio.h> #include <linux/slab.h> #include <linux/smp.h> #include <linux/smp_lock.h> #include <linux/mutex.h> #include <linux/sunrpc/types.h> #include <linux/sunrpc/stats.h> #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/svc.h> #include <linux/sunrpc/svcsock.h> #include <linux/lockd/lockd.h> #include <linux/nfs.h> #define NLMDBG_FACILITY NLMDBG_SVC #define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE) #define ALLOWED_SIGS (sigmask(SIGKILL)) static struct svc_program nlmsvc_program; struct nlmsvc_binding * nlmsvc_ops; EXPORT_SYMBOL(nlmsvc_ops); static DEFINE_MUTEX(nlmsvc_mutex); static unsigned int nlmsvc_users; static pid_t nlmsvc_pid; int nlmsvc_grace_period; unsigned long nlmsvc_timeout; static DECLARE_COMPLETION(lockd_start_done); static DECLARE_WAIT_QUEUE_HEAD(lockd_exit); /* * These can be set at insmod time (useful for NFS as root filesystem), * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003 */ static unsigned long nlm_grace_period; static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO; static int nlm_udpport, nlm_tcpport; /* * Constants needed for the sysctl interface. */ static const unsigned long nlm_grace_period_min = 0; static const unsigned long nlm_grace_period_max = 240; static const unsigned long nlm_timeout_min = 3; static const unsigned long nlm_timeout_max = 20; static const int nlm_port_min = 0, nlm_port_max = 65535; static struct ctl_table_header * nlm_sysctl_table; static unsigned long set_grace_period(void) { unsigned long grace_period; /* Note: nlm_timeout should always be nonzero */ if (nlm_grace_period) grace_period = ((nlm_grace_period + nlm_timeout - 1) / nlm_timeout) * nlm_timeout * HZ; else grace_period = nlm_timeout * 5 * HZ; nlmsvc_grace_period = 1; return grace_period + jiffies; } static inline void clear_grace_period(void) { nlmsvc_grace_period = 0; } /* * This is the lockd kernel thread */ static void lockd(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; int err = 0; unsigned long grace_period_expire; /* Lock module and set up kernel thread */ /* lockd_up is waiting for us to startup, so will * be holding a reference to this module, so it * is safe to just claim another reference */ __module_get(THIS_MODULE); lock_kernel(); /* * Let our maker know we're running. */ nlmsvc_pid = current->pid; complete(&lockd_start_done); daemonize("lockd"); /* Process request with signals blocked, but allow SIGKILL. */ allow_signal(SIGKILL); /* kick rpciod */ rpciod_up(); dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); if (!nlm_timeout) nlm_timeout = LOCKD_DFLT_TIMEO; nlmsvc_timeout = nlm_timeout * HZ; grace_period_expire = set_grace_period(); /* * The main request loop. We don't terminate until the last * NFS mount or NFS daemon has gone away, and we've been sent a * signal, or else another process has taken over our job. */ while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) { long timeout = MAX_SCHEDULE_TIMEOUT; if (signalled()) { flush_signals(current); if (nlmsvc_ops) { nlmsvc_invalidate_all(); grace_period_expire = set_grace_period(); } } /* * Retry any blocked locks that have been notified by * the VFS. Don't do this during grace period. * (Theoretically, there shouldn't even be blocked locks * during grace period). */ if (!nlmsvc_grace_period) { timeout = nlmsvc_retry_blocked(); } else if (time_before(grace_period_expire, jiffies)) clear_grace_period(); /* * Find a socket with data available and call its * recvfrom routine. */ err = svc_recv(serv, rqstp, timeout); if (err == -EAGAIN || err == -EINTR) continue; if (err < 0) { printk(KERN_WARNING "lockd: terminating on error %d\n", -err); break; } dprintk("lockd: request from %08x\n", (unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr)); svc_process(serv, rqstp); } flush_signals(current); /* * Check whether there's a new lockd process before * shutting down the hosts and clearing the slot. */ if (!nlmsvc_pid || current->pid == nlmsvc_pid) { if (nlmsvc_ops) nlmsvc_invalidate_all(); nlm_shutdown_hosts(); nlmsvc_pid = 0; } else printk(KERN_DEBUG "lockd: new process, skipping host shutdown\n"); wake_up(&lockd_exit); /* Exit the RPC thread */ svc_exit_thread(rqstp); /* release rpciod */ rpciod_down(); /* Release module */ unlock_kernel(); module_put_and_exit(0); } /* * Bring up the lockd process if it's not already up. */ int lockd_up(void) { static int warned; struct svc_serv * serv; int error = 0; mutex_lock(&nlmsvc_mutex); /* * Unconditionally increment the user count ... this is * the number of clients who _want_ a lockd process. */ nlmsvc_users++; /* * Check whether we're already up and running. */ if (nlmsvc_pid) goto out; /* * Sanity check: if there's no pid, * we should be the first user ... */ if (nlmsvc_users > 1) printk(KERN_WARNING "lockd_up: no pid, %d users??\n", nlmsvc_users); error = -ENOMEM; serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE); if (!serv) { printk(KERN_WARNING "lockd_up: create service failed\n"); goto out; } if ((error = svc_makesock(serv, IPPROTO_UDP, nlm_udpport)) < 0 #ifdef CONFIG_NFSD_TCP || (error = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport)) < 0 #endif ) { if (warned++ == 0) printk(KERN_WARNING "lockd_up: makesock failed, error=%d\n", error); goto destroy_and_out; } warned = 0; /* * Create the kernel thread and wait for it to start. */ error = svc_create_thread(lockd, serv); if (error) { printk(KERN_WARNING "lockd_up: create thread failed, error=%d\n", error); goto destroy_and_out; } wait_for_completion(&lockd_start_done); /* * Note: svc_serv structures have an initial use count of 1, * so we exit through here on both success and failure. */ destroy_and_out: svc_destroy(serv); out: mutex_unlock(&nlmsvc_mutex); return error; } EXPORT_SYMBOL(lockd_up); /* * Decrement the user count and bring down lockd if we're the last. */ void lockd_down(void) { static int warned; mutex_lock(&nlmsvc_mutex); if (nlmsvc_users) { if (--nlmsvc_users) goto out; } else printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid); if (!nlmsvc_pid) { if (warned++ == 0) printk(KERN_WARNING "lockd_down: no lockd running.\n"); goto out; } warned = 0; kill_proc(nlmsvc_pid, SIGKILL, 1); /* * Wait for the lockd process to exit, but since we're holding * the lockd semaphore, we can't wait around forever ... */ clear_thread_flag(TIF_SIGPENDING); interruptible_sleep_on_timeout(&lockd_exit, HZ); if (nlmsvc_pid) { printk(KERN_WARNING "lockd_down: lockd failed to exit, clearing pid\n"); nlmsvc_pid = 0; } spin_lock_irq(¤t->sighand->siglock); recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); out: mutex_unlock(&nlmsvc_mutex); } EXPORT_SYMBOL(lockd_down); /* * Sysctl parameters (same as module parameters, different interface). */ /* Something that isn't CTL_ANY, CTL_NONE or a value that may clash. */ #define CTL_UNNUMBERED -2 static ctl_table nlm_sysctls[] = { { .ctl_name = CTL_UNNUMBERED, .procname = "nlm_grace_period", .data = &nlm_grace_period, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = &proc_doulongvec_minmax, .extra1 = (unsigned long *) &nlm_grace_period_min, .extra2 = (unsigned long *) &nlm_grace_period_max, }, { .ctl_name = CTL_UNNUMBERED, .procname = "nlm_timeout", .data = &nlm_timeout, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = &proc_doulongvec_minmax, .extra1 = (unsigned long *) &nlm_timeout_min, .extra2 = (unsigned long *) &nlm_timeout_max, }, { .ctl_name = CTL_UNNUMBERED, .procname = "nlm_udpport", .data = &nlm_udpport, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &proc_dointvec_minmax, .extra1 = (int *) &nlm_port_min, .extra2 = (int *) &nlm_port_max, }, { .ctl_name = CTL_UNNUMBERED, .procname = "nlm_tcpport", .data = &nlm_tcpport, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &proc_dointvec_minmax, .extra1 = (int *) &nlm_port_min, .extra2 = (int *) &nlm_port_max, }, { .ctl_name = 0 } }; static ctl_table nlm_sysctl_dir[] = { { .ctl_name = CTL_UNNUMBERED, .procname = "nfs", .mode = 0555, .child = nlm_sysctls, }, { .ctl_name = 0 } }; static ctl_table nlm_sysctl_root[] = { { .ctl_name = CTL_FS, .procname = "fs", .mode = 0555, .child = nlm_sysctl_dir, }, { .ctl_name = 0 } }; /* * Module (and driverfs) parameters. */ #define param_set_min_max(name, type, which_strtol, min, max) \ static int param_set_##name(const char *val, struct kernel_param *kp) \ { \ char *endp; \ __typeof__(type) num = which_strtol(val, &endp, 0); \ if (endp == val || *endp || num < (min) || num > (max)) \ return -EINVAL; \ *((int *) kp->arg) = num; \ return 0; \ } static inline int is_callback(u32 proc) { return proc == NLMPROC_GRANTED || proc == NLMPROC_GRANTED_MSG || proc == NLMPROC_TEST_RES || proc == NLMPROC_LOCK_RES || proc == NLMPROC_CANCEL_RES || proc == NLMPROC_UNLOCK_RES || proc == NLMPROC_NSM_NOTIFY; } static int lockd_authenticate(struct svc_rqst *rqstp) { rqstp->rq_client = NULL; switch (rqstp->rq_authop->flavour) { case RPC_AUTH_NULL: case RPC_AUTH_UNIX: if (rqstp->rq_proc == 0) return SVC_OK; if (is_callback(rqstp->rq_proc)) { /* Leave it to individual procedures to * call nlmsvc_lookup_host(rqstp) */ return SVC_OK; } return svc_set_client(rqstp); } return SVC_DENIED; } param_set_min_max(port, int, simple_strtol, 0, 65535) param_set_min_max(grace_period, unsigned long, simple_strtoul, nlm_grace_period_min, nlm_grace_period_max) param_set_min_max(timeout, unsigned long, simple_strtoul, nlm_timeout_min, nlm_timeout_max) MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>"); MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION "."); MODULE_LICENSE("GPL"); module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong, &nlm_grace_period, 0644); module_param_call(nlm_timeout, param_set_timeout, param_get_ulong, &nlm_timeout, 0644); module_param_call(nlm_udpport, param_set_port, param_get_int, &nlm_udpport, 0644); module_param_call(nlm_tcpport, param_set_port, param_get_int, &nlm_tcpport, 0644); /* * Initialising and terminating the module. */ static int __init init_nlm(void) { nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0); return nlm_sysctl_table ? 0 : -ENOMEM; } static void __exit exit_nlm(void) { /* FIXME: delete all NLM clients */ nlm_shutdown_hosts(); unregister_sysctl_table(nlm_sysctl_table); } module_init(init_nlm); module_exit(exit_nlm); /* * Define NLM program and procedures */ static struct svc_version nlmsvc_version1 = { .vs_vers = 1, .vs_nproc = 17, .vs_proc = nlmsvc_procedures, .vs_xdrsize = NLMSVC_XDRSIZE, }; static struct svc_version nlmsvc_version3 = { .vs_vers = 3, .vs_nproc = 24, .vs_proc = nlmsvc_procedures, .vs_xdrsize = NLMSVC_XDRSIZE, }; #ifdef CONFIG_LOCKD_V4 static struct svc_version nlmsvc_version4 = { .vs_vers = 4, .vs_nproc = 24, .vs_proc = nlmsvc_procedures4, .vs_xdrsize = NLMSVC_XDRSIZE, }; #endif static struct svc_version * nlmsvc_version[] = { [1] = &nlmsvc_version1, [3] = &nlmsvc_version3, #ifdef CONFIG_LOCKD_V4 [4] = &nlmsvc_version4, #endif }; static struct svc_stat nlmsvc_stats; #define NLM_NRVERS ARRAY_SIZE(nlmsvc_version) static struct svc_program nlmsvc_program = { .pg_prog = NLM_PROGRAM, /* program number */ .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */ .pg_vers = nlmsvc_version, /* version table */ .pg_name = "lockd", /* service name */ .pg_class = "nfsd", /* share authentication with nfsd */ .pg_stats = &nlmsvc_stats, /* stats table */ .pg_authenticate = &lockd_authenticate /* export authentication */ };