diff options
Diffstat (limited to 'fs/lockd/svc.c')
| -rw-r--r-- | fs/lockd/svc.c | 579 |
1 files changed, 579 insertions, 0 deletions
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c new file mode 100644 index 00000000..f1bacf1a --- /dev/null +++ b/fs/lockd/svc.c @@ -0,0 +1,579 @@ +/* + * 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/smp.h> +#include <linux/smp_lock.h> +#include <linux/mutex.h> +#include <linux/kthread.h> +#include <linux/freezer.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 <net/ip.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_GPL(nlmsvc_ops); + +static DEFINE_MUTEX(nlmsvc_mutex); +static unsigned int nlmsvc_users; +static struct task_struct *nlmsvc_task; +static struct svc_rqst *nlmsvc_rqst; +unsigned long nlmsvc_timeout; + +/* + * 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; + +/* RLIM_NOFILE defaults to 1024. That seems like a reasonable default here. */ +static unsigned int nlm_max_connections = 1024; + +/* + * 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; + +#ifdef CONFIG_SYSCTL +static struct ctl_table_header * nlm_sysctl_table; +#endif + +static unsigned long get_lockd_grace_period(void) +{ + /* Note: nlm_timeout should always be nonzero */ + if (nlm_grace_period) + return roundup(nlm_grace_period, nlm_timeout) * HZ; + else + return nlm_timeout * 5 * HZ; +} + +static struct lock_manager lockd_manager = { +}; + +static void grace_ender(struct work_struct *not_used) +{ + locks_end_grace(&lockd_manager); +} + +static DECLARE_DELAYED_WORK(grace_period_end, grace_ender); + +static void set_grace_period(void) +{ + unsigned long grace_period = get_lockd_grace_period(); + + locks_start_grace(&lockd_manager); + cancel_delayed_work_sync(&grace_period_end); + schedule_delayed_work(&grace_period_end, grace_period); +} + +static void restart_grace(void) +{ + if (nlmsvc_ops) { + cancel_delayed_work_sync(&grace_period_end); + locks_end_grace(&lockd_manager); + nlmsvc_invalidate_all(); + set_grace_period(); + } +} + +/* + * This is the lockd kernel thread + */ +static int +lockd(void *vrqstp) +{ + int err = 0, preverr = 0; + struct svc_rqst *rqstp = vrqstp; + + /* try_to_freeze() is called from svc_recv() */ + set_freezable(); + + /* Allow SIGKILL to tell lockd to drop all of its locks */ + allow_signal(SIGKILL); + + dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n"); + + /* + * FIXME: it would be nice if lockd didn't spend its entire life + * running under the BKL. At the very least, it would be good to + * have someone clarify what it's intended to protect here. I've + * seen some handwavy posts about posix locking needing to be + * done under the BKL, but it's far from clear. + */ + lock_kernel(); + + if (!nlm_timeout) + nlm_timeout = LOCKD_DFLT_TIMEO; + nlmsvc_timeout = nlm_timeout * HZ; + + set_grace_period(); + + /* + * The main request loop. We don't terminate until the last + * NFS mount or NFS daemon has gone away. + */ + while (!kthread_should_stop()) { + long timeout = MAX_SCHEDULE_TIMEOUT; + RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); + + /* update sv_maxconn if it has changed */ + rqstp->rq_server->sv_maxconn = nlm_max_connections; + + if (signalled()) { + flush_signals(current); + restart_grace(); + continue; + } + + timeout = nlmsvc_retry_blocked(); + + /* + * Find a socket with data available and call its + * recvfrom routine. + */ + err = svc_recv(rqstp, timeout); + if (err == -EAGAIN || err == -EINTR) { + preverr = err; + continue; + } + if (err < 0) { + if (err != preverr) { + printk(KERN_WARNING "%s: unexpected error " + "from svc_recv (%d)\n", __func__, err); + preverr = err; + } + schedule_timeout_interruptible(HZ); + continue; + } + preverr = err; + + dprintk("lockd: request from %s\n", + svc_print_addr(rqstp, buf, sizeof(buf))); + + svc_process(rqstp); + } + flush_signals(current); + cancel_delayed_work_sync(&grace_period_end); + locks_end_grace(&lockd_manager); + if (nlmsvc_ops) + nlmsvc_invalidate_all(); + nlm_shutdown_hosts(); + unlock_kernel(); + return 0; +} + +static int create_lockd_listener(struct svc_serv *serv, const char *name, + const int family, const unsigned short port) +{ + struct svc_xprt *xprt; + + xprt = svc_find_xprt(serv, name, family, 0); + if (xprt == NULL) + return svc_create_xprt(serv, name, family, port, + SVC_SOCK_DEFAULTS); + svc_xprt_put(xprt); + return 0; +} + +static int create_lockd_family(struct svc_serv *serv, const int family) +{ + int err; + + err = create_lockd_listener(serv, "udp", family, nlm_udpport); + if (err < 0) + return err; + + return create_lockd_listener(serv, "tcp", family, nlm_tcpport); +} + +/* + * Ensure there are active UDP and TCP listeners for lockd. + * + * Even if we have only TCP NFS mounts and/or TCP NFSDs, some + * local services (such as rpc.statd) still require UDP, and + * some NFS servers do not yet support NLM over TCP. + * + * Returns zero if all listeners are available; otherwise a + * negative errno value is returned. + */ +static int make_socks(struct svc_serv *serv) +{ + static int warned; + int err; + + err = create_lockd_family(serv, PF_INET); + if (err < 0) + goto out_err; + + err = create_lockd_family(serv, PF_INET6); + if (err < 0 && err != -EAFNOSUPPORT) + goto out_err; + + warned = 0; + return 0; + +out_err: + if (warned++ == 0) + printk(KERN_WARNING + "lockd_up: makesock failed, error=%d\n", err); + return err; +} + +/* + * Bring up the lockd process if it's not already up. + */ +int lockd_up(void) +{ + struct svc_serv *serv; + int error = 0; + + mutex_lock(&nlmsvc_mutex); + /* + * Check whether we're already up and running. + */ + if (nlmsvc_rqst) + goto out; + + /* + * Sanity check: if there's no pid, + * we should be the first user ... + */ + if (nlmsvc_users) + printk(KERN_WARNING + "lockd_up: no pid, %d users??\n", nlmsvc_users); + + error = -ENOMEM; + serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, NULL); + if (!serv) { + printk(KERN_WARNING "lockd_up: create service failed\n"); + goto out; + } + + error = make_socks(serv); + if (error < 0) + goto destroy_and_out; + + /* + * Create the kernel thread and wait for it to start. + */ + nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); + if (IS_ERR(nlmsvc_rqst)) { + error = PTR_ERR(nlmsvc_rqst); + nlmsvc_rqst = NULL; + printk(KERN_WARNING + "lockd_up: svc_rqst allocation failed, error=%d\n", + error); + goto destroy_and_out; + } + + svc_sock_update_bufs(serv); + serv->sv_maxconn = nlm_max_connections; + + nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name); + if (IS_ERR(nlmsvc_task)) { + error = PTR_ERR(nlmsvc_task); + svc_exit_thread(nlmsvc_rqst); + nlmsvc_task = NULL; + nlmsvc_rqst = NULL; + printk(KERN_WARNING + "lockd_up: kthread_run failed, error=%d\n", error); + goto destroy_and_out; + } + + /* + * 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: + if (!error) + nlmsvc_users++; + mutex_unlock(&nlmsvc_mutex); + return error; +} +EXPORT_SYMBOL_GPL(lockd_up); + +/* + * Decrement the user count and bring down lockd if we're the last. + */ +void +lockd_down(void) +{ + mutex_lock(&nlmsvc_mutex); + if (nlmsvc_users) { + if (--nlmsvc_users) + goto out; + } else { + printk(KERN_ERR "lockd_down: no users! task=%p\n", + nlmsvc_task); + BUG(); + } + + if (!nlmsvc_task) { + printk(KERN_ERR "lockd_down: no lockd running.\n"); + BUG(); + } + kthread_stop(nlmsvc_task); + svc_exit_thread(nlmsvc_rqst); + nlmsvc_task = NULL; + nlmsvc_rqst = NULL; +out: + mutex_unlock(&nlmsvc_mutex); +} +EXPORT_SYMBOL_GPL(lockd_down); + +#ifdef CONFIG_SYSCTL + +/* + * Sysctl parameters (same as module parameters, different interface). + */ + +static ctl_table nlm_sysctls[] = { + { + .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, + }, + { + .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, + }, + { + .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, + }, + { + .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, + }, + { + .procname = "nsm_use_hostnames", + .data = &nsm_use_hostnames, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "nsm_local_state", + .data = &nsm_local_state, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static ctl_table nlm_sysctl_dir[] = { + { + .procname = "nfs", + .mode = 0555, + .child = nlm_sysctls, + }, + { } +}; + +static ctl_table nlm_sysctl_root[] = { + { + .procname = "fs", + .mode = 0555, + .child = nlm_sysctl_dir, + }, + { } +}; + +#endif /* CONFIG_SYSCTL */ + +/* + * Module (and sysfs) 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); +module_param(nsm_use_hostnames, bool, 0644); +module_param(nlm_max_connections, uint, 0644); + +/* + * Initialising and terminating the module. + */ + +static int __init init_nlm(void) +{ +#ifdef CONFIG_SYSCTL + nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root); + return nlm_sysctl_table ? 0 : -ENOMEM; +#else + return 0; +#endif +} + +static void __exit exit_nlm(void) +{ + /* FIXME: delete all NLM clients */ + nlm_shutdown_hosts(); +#ifdef CONFIG_SYSCTL + unregister_sysctl_table(nlm_sysctl_table); +#endif +} + +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 */ +}; |