diff options
Diffstat (limited to 'fs/lockd/svc.c')
| -rw-r--r-- | fs/lockd/svc.c | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c new file mode 100644 index 00000000000..b82e470912e --- /dev/null +++ b/fs/lockd/svc.c @@ -0,0 +1,519 @@ +/* + * 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/config.h> +#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/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 DECLARE_MUTEX(nlmsvc_sema); +static unsigned int nlmsvc_users; +static pid_t nlmsvc_pid; +int nlmsvc_grace_period; +unsigned long nlmsvc_timeout; + +static DECLARE_MUTEX_LOCKED(lockd_start); +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; + up(&lockd_start); + + 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); + + } + + /* + * 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; + + down(&nlmsvc_sema); + /* + * 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; + } + down(&lockd_start); + + /* + * 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: + up(&nlmsvc_sema); + 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; + + down(&nlmsvc_sema); + 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: + up(&nlmsvc_sema); +} +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(int), + .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(int), + .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 (sizeof(nlmsvc_version)/sizeof(nlmsvc_version[0])) +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 */ +}; |