4 * This is the central lockd service.
6 * FIXME: Separate the lockd NFS server functionality from the lockd NFS
7 * client functionality. Oh why didn't Sun create two separate
8 * services in the first place?
10 * Authors: Olaf Kirch (okir@monad.swb.de)
12 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
15 #include <linux/config.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/sysctl.h>
19 #include <linux/moduleparam.h>
21 #include <linux/sched.h>
22 #include <linux/errno.h>
24 #include <linux/uio.h>
25 #include <linux/slab.h>
26 #include <linux/smp.h>
27 #include <linux/smp_lock.h>
29 #include <linux/sunrpc/types.h>
30 #include <linux/sunrpc/stats.h>
31 #include <linux/sunrpc/clnt.h>
32 #include <linux/sunrpc/svc.h>
33 #include <linux/sunrpc/svcsock.h>
34 #include <linux/lockd/lockd.h>
35 #include <linux/nfs.h>
37 #define NLMDBG_FACILITY NLMDBG_SVC
38 #define LOCKD_BUFSIZE (1024 + NLMSVC_XDRSIZE)
39 #define ALLOWED_SIGS (sigmask(SIGKILL))
41 extern struct svc_program nlmsvc_program;
42 struct nlmsvc_binding * nlmsvc_ops;
43 static DECLARE_MUTEX(nlmsvc_sema);
44 static unsigned int nlmsvc_users;
45 static pid_t nlmsvc_pid;
46 int nlmsvc_grace_period;
47 unsigned long nlmsvc_timeout;
49 static DECLARE_MUTEX_LOCKED(lockd_start);
50 static DECLARE_WAIT_QUEUE_HEAD(lockd_exit);
53 * These can be set at insmod time (useful for NFS as root filesystem),
54 * and also changed through the sysctl interface. -- Jamie Lokier, Aug 2003
56 static unsigned long nlm_grace_period;
57 static unsigned long nlm_timeout = LOCKD_DFLT_TIMEO;
58 static int nlm_udpport, nlm_tcpport;
61 * Constants needed for the sysctl interface.
63 static const unsigned long nlm_grace_period_min = 0;
64 static const unsigned long nlm_grace_period_max = 240;
65 static const unsigned long nlm_timeout_min = 3;
66 static const unsigned long nlm_timeout_max = 20;
67 static const int nlm_port_min = 0, nlm_port_max = 65535;
69 static struct ctl_table_header * nlm_sysctl_table;
71 static unsigned long set_grace_period(void)
73 unsigned long grace_period;
75 /* Note: nlm_timeout should always be nonzero */
77 grace_period = ((nlm_grace_period + nlm_timeout - 1)
78 / nlm_timeout) * nlm_timeout * HZ;
80 grace_period = nlm_timeout * 5 * HZ;
81 nlmsvc_grace_period = 1;
82 return grace_period + jiffies;
85 static inline void clear_grace_period(void)
87 nlmsvc_grace_period = 0;
91 * This is the lockd kernel thread
94 lockd(struct svc_rqst *rqstp)
96 struct svc_serv *serv = rqstp->rq_server;
98 unsigned long grace_period_expire;
100 /* Lock module and set up kernel thread */
101 /* lockd_up is waiting for us to startup, so will
102 * be holding a reference to this module, so it
103 * is safe to just claim another reference
105 __module_get(THIS_MODULE);
109 * Let our maker know we're running.
111 nlmsvc_pid = current->pid;
116 /* Process request with signals blocked, but allow SIGKILL. */
117 allow_signal(SIGKILL);
122 dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
125 nlm_timeout = LOCKD_DFLT_TIMEO;
126 nlmsvc_timeout = nlm_timeout * HZ;
128 grace_period_expire = set_grace_period();
131 * The main request loop. We don't terminate until the last
132 * NFS mount or NFS daemon has gone away, and we've been sent a
133 * signal, or else another process has taken over our job.
135 while ((nlmsvc_users || !signalled()) && nlmsvc_pid == current->pid) {
136 long timeout = MAX_SCHEDULE_TIMEOUT;
139 flush_signals(current);
141 nlmsvc_invalidate_all();
142 grace_period_expire = set_grace_period();
147 * Retry any blocked locks that have been notified by
148 * the VFS. Don't do this during grace period.
149 * (Theoretically, there shouldn't even be blocked locks
150 * during grace period).
152 if (!nlmsvc_grace_period) {
153 timeout = nlmsvc_retry_blocked();
154 } else if (time_before(grace_period_expire, jiffies))
155 clear_grace_period();
158 * Find a socket with data available and call its
161 err = svc_recv(serv, rqstp, timeout);
162 if (err == -EAGAIN || err == -EINTR)
166 "lockd: terminating on error %d\n",
171 dprintk("lockd: request from %08x\n",
172 (unsigned)ntohl(rqstp->rq_addr.sin_addr.s_addr));
174 svc_process(serv, rqstp);
179 * Check whether there's a new lockd process before
180 * shutting down the hosts and clearing the slot.
182 if (!nlmsvc_pid || current->pid == nlmsvc_pid) {
184 nlmsvc_invalidate_all();
185 nlm_shutdown_hosts();
189 "lockd: new process, skipping host shutdown\n");
190 wake_up(&lockd_exit);
192 /* Exit the RPC thread */
193 svc_exit_thread(rqstp);
200 module_put_and_exit(0);
204 * Bring up the lockd process if it's not already up.
210 struct svc_serv * serv;
215 * Unconditionally increment the user count ... this is
216 * the number of clients who _want_ a lockd process.
220 * Check whether we're already up and running.
226 * Sanity check: if there's no pid,
227 * we should be the first user ...
229 if (nlmsvc_users > 1)
231 "lockd_up: no pid, %d users??\n", nlmsvc_users);
234 serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE);
236 printk(KERN_WARNING "lockd_up: create service failed\n");
240 if ((error = svc_makesock(serv, IPPROTO_UDP, nlm_udpport)) < 0
241 #ifdef CONFIG_NFSD_TCP
242 || (error = svc_makesock(serv, IPPROTO_TCP, nlm_tcpport)) < 0
247 "lockd_up: makesock failed, error=%d\n", error);
248 goto destroy_and_out;
253 * Create the kernel thread and wait for it to start.
255 error = svc_create_thread(lockd, serv);
258 "lockd_up: create thread failed, error=%d\n", error);
259 goto destroy_and_out;
264 * Note: svc_serv structures have an initial use count of 1,
265 * so we exit through here on both success and failure.
275 * Decrement the user count and bring down lockd if we're the last.
287 printk(KERN_WARNING "lockd_down: no users! pid=%d\n", nlmsvc_pid);
291 printk(KERN_WARNING "lockd_down: no lockd running.\n");
296 kill_proc(nlmsvc_pid, SIGKILL, 1);
298 * Wait for the lockd process to exit, but since we're holding
299 * the lockd semaphore, we can't wait around forever ...
301 clear_thread_flag(TIF_SIGPENDING);
302 interruptible_sleep_on_timeout(&lockd_exit, HZ);
305 "lockd_down: lockd failed to exit, clearing pid\n");
308 spin_lock_irq(¤t->sighand->siglock);
310 spin_unlock_irq(¤t->sighand->siglock);
316 * Sysctl parameters (same as module parameters, different interface).
319 /* Something that isn't CTL_ANY, CTL_NONE or a value that may clash. */
320 #define CTL_UNNUMBERED -2
322 static ctl_table nlm_sysctls[] = {
324 .ctl_name = CTL_UNNUMBERED,
325 .procname = "nlm_grace_period",
326 .data = &nlm_grace_period,
327 .maxlen = sizeof(int),
329 .proc_handler = &proc_doulongvec_minmax,
330 .extra1 = (unsigned long *) &nlm_grace_period_min,
331 .extra2 = (unsigned long *) &nlm_grace_period_max,
334 .ctl_name = CTL_UNNUMBERED,
335 .procname = "nlm_timeout",
336 .data = &nlm_timeout,
337 .maxlen = sizeof(int),
339 .proc_handler = &proc_doulongvec_minmax,
340 .extra1 = (unsigned long *) &nlm_timeout_min,
341 .extra2 = (unsigned long *) &nlm_timeout_max,
344 .ctl_name = CTL_UNNUMBERED,
345 .procname = "nlm_udpport",
346 .data = &nlm_udpport,
347 .maxlen = sizeof(int),
349 .proc_handler = &proc_dointvec_minmax,
350 .extra1 = (int *) &nlm_port_min,
351 .extra2 = (int *) &nlm_port_max,
354 .ctl_name = CTL_UNNUMBERED,
355 .procname = "nlm_tcpport",
356 .data = &nlm_tcpport,
357 .maxlen = sizeof(int),
359 .proc_handler = &proc_dointvec_minmax,
360 .extra1 = (int *) &nlm_port_min,
361 .extra2 = (int *) &nlm_port_max,
366 static ctl_table nlm_sysctl_dir[] = {
368 .ctl_name = CTL_UNNUMBERED,
371 .child = nlm_sysctls,
376 static ctl_table nlm_sysctl_root[] = {
381 .child = nlm_sysctl_dir,
387 * Module (and driverfs) parameters.
390 #define param_set_min_max(name, type, which_strtol, min, max) \
391 static int param_set_##name(const char *val, struct kernel_param *kp) \
394 __typeof__(type) num = which_strtol(val, &endp, 0); \
395 if (endp == val || *endp || num < (min) || num > (max)) \
397 *((int *) kp->arg) = num; \
401 param_set_min_max(port, int, simple_strtol, 0, 65535)
402 param_set_min_max(grace_period, unsigned long, simple_strtoul,
403 nlm_grace_period_min, nlm_grace_period_max)
404 param_set_min_max(timeout, unsigned long, simple_strtoul,
405 nlm_timeout_min, nlm_timeout_max)
407 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
408 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
409 MODULE_LICENSE("GPL");
411 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
412 &nlm_grace_period, 0644);
413 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
415 module_param_call(nlm_udpport, param_set_port, param_get_int,
417 module_param_call(nlm_tcpport, param_set_port, param_get_int,
421 * Initialising and terminating the module.
424 static int __init init_nlm(void)
426 nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root, 0);
427 return nlm_sysctl_table ? 0 : -ENOMEM;
430 static void __exit exit_nlm(void)
432 /* FIXME: delete all NLM clients */
433 nlm_shutdown_hosts();
434 unregister_sysctl_table(nlm_sysctl_table);
437 module_init(init_nlm);
438 module_exit(exit_nlm);
441 * Define NLM program and procedures
443 static struct svc_version nlmsvc_version1 = {
446 .vs_proc = nlmsvc_procedures,
447 .vs_xdrsize = NLMSVC_XDRSIZE,
449 static struct svc_version nlmsvc_version3 = {
452 .vs_proc = nlmsvc_procedures,
453 .vs_xdrsize = NLMSVC_XDRSIZE,
455 #ifdef CONFIG_LOCKD_V4
456 static struct svc_version nlmsvc_version4 = {
459 .vs_proc = nlmsvc_procedures4,
460 .vs_xdrsize = NLMSVC_XDRSIZE,
463 static struct svc_version * nlmsvc_version[] = {
464 [1] = &nlmsvc_version1,
465 [3] = &nlmsvc_version3,
466 #ifdef CONFIG_LOCKD_V4
467 [4] = &nlmsvc_version4,
471 static struct svc_stat nlmsvc_stats;
473 #define NLM_NRVERS (sizeof(nlmsvc_version)/sizeof(nlmsvc_version[0]))
474 struct svc_program nlmsvc_program = {
475 .pg_prog = NLM_PROGRAM, /* program number */
476 .pg_nvers = NLM_NRVERS, /* number of entries in nlmsvc_version */
477 .pg_vers = nlmsvc_version, /* version table */
478 .pg_name = "lockd", /* service name */
479 .pg_class = "nfsd", /* share authentication with nfsd */
480 .pg_stats = &nlmsvc_stats, /* stats table */