2 * linux/fs/lockd/clntproc.c
4 * RPC procedures for the client side NLM implementation
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
9 #include <linux/config.h>
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/errno.h>
14 #include <linux/nfs_fs.h>
15 #include <linux/utsname.h>
16 #include <linux/smp_lock.h>
17 #include <linux/sunrpc/clnt.h>
18 #include <linux/sunrpc/svc.h>
19 #include <linux/lockd/lockd.h>
20 #include <linux/lockd/sm_inter.h>
22 #define NLMDBG_FACILITY NLMDBG_CLIENT
23 #define NLMCLNT_GRACE_WAIT (5*HZ)
24 #define NLMCLNT_POLL_TIMEOUT (30*HZ)
26 static int nlmclnt_test(struct nlm_rqst *, struct file_lock *);
27 static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
28 static int nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
29 static int nlm_stat_to_errno(u32 stat);
30 static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
32 static const struct rpc_call_ops nlmclnt_unlock_ops;
33 static const struct rpc_call_ops nlmclnt_cancel_ops;
36 * Cookie counter for NLM requests
38 static u32 nlm_cookie = 0x1234;
40 static inline void nlmclnt_next_cookie(struct nlm_cookie *c)
42 memcpy(c->data, &nlm_cookie, 4);
43 memset(c->data+4, 0, 4);
48 static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
50 atomic_inc(&lockowner->count);
54 static void nlm_put_lockowner(struct nlm_lockowner *lockowner)
56 if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
58 list_del(&lockowner->list);
59 spin_unlock(&lockowner->host->h_lock);
60 nlm_release_host(lockowner->host);
64 static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid)
66 struct nlm_lockowner *lockowner;
67 list_for_each_entry(lockowner, &host->h_lockowners, list) {
68 if (lockowner->pid == pid)
74 static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
78 res = host->h_pidcount++;
79 } while (nlm_pidbusy(host, res) < 0);
83 static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
85 struct nlm_lockowner *lockowner;
86 list_for_each_entry(lockowner, &host->h_lockowners, list) {
87 if (lockowner->owner != owner)
89 return nlm_get_lockowner(lockowner);
94 static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
96 struct nlm_lockowner *res, *new = NULL;
98 spin_lock(&host->h_lock);
99 res = __nlm_find_lockowner(host, owner);
101 spin_unlock(&host->h_lock);
102 new = (struct nlm_lockowner *)kmalloc(sizeof(*new), GFP_KERNEL);
103 spin_lock(&host->h_lock);
104 res = __nlm_find_lockowner(host, owner);
105 if (res == NULL && new != NULL) {
107 atomic_set(&new->count, 1);
109 new->pid = __nlm_alloc_pid(host);
110 new->host = nlm_get_host(host);
111 list_add(&new->list, &host->h_lockowners);
115 spin_unlock(&host->h_lock);
121 * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
123 static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
125 struct nlm_args *argp = &req->a_args;
126 struct nlm_lock *lock = &argp->lock;
128 nlmclnt_next_cookie(&argp->cookie);
129 argp->state = nsm_local_state;
130 memcpy(&lock->fh, NFS_FH(fl->fl_file->f_dentry->d_inode), sizeof(struct nfs_fh));
131 lock->caller = system_utsname.nodename;
132 lock->oh.data = req->a_owner;
133 lock->oh.len = sprintf(req->a_owner, "%d@%s",
134 current->pid, system_utsname.nodename);
135 locks_copy_lock(&lock->fl, fl);
138 static void nlmclnt_release_lockargs(struct nlm_rqst *req)
140 struct file_lock *fl = &req->a_args.lock.fl;
142 if (fl->fl_ops && fl->fl_ops->fl_release_private)
143 fl->fl_ops->fl_release_private(fl);
147 * Initialize arguments for GRANTED call. The nlm_rqst structure
148 * has been cleared already.
151 nlmclnt_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
153 locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
154 memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
155 call->a_args.lock.caller = system_utsname.nodename;
156 call->a_args.lock.oh.len = lock->oh.len;
158 /* set default data area */
159 call->a_args.lock.oh.data = call->a_owner;
161 if (lock->oh.len > NLMCLNT_OHSIZE) {
162 void *data = kmalloc(lock->oh.len, GFP_KERNEL);
164 nlmclnt_freegrantargs(call);
167 call->a_args.lock.oh.data = (u8 *) data;
170 memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
175 nlmclnt_freegrantargs(struct nlm_rqst *call)
177 struct file_lock *fl = &call->a_args.lock.fl;
179 * Check whether we allocated memory for the owner.
181 if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
182 kfree(call->a_args.lock.oh.data);
184 if (fl->fl_ops && fl->fl_ops->fl_release_private)
185 fl->fl_ops->fl_release_private(fl);
189 * This is the main entry point for the NLM client.
192 nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
194 struct nfs_server *nfssrv = NFS_SERVER(inode);
195 struct nlm_host *host;
196 struct nlm_rqst reqst, *call = &reqst;
199 int status, proto, vers;
201 vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1;
202 if (NFS_PROTO(inode)->version > 3) {
203 printk(KERN_NOTICE "NFSv4 file locking not implemented!\n");
207 /* Retrieve transport protocol from NFS client */
208 proto = NFS_CLIENT(inode)->cl_xprt->prot;
210 if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers)))
213 /* Create RPC client handle if not there, and copy soft
214 * and intr flags from NFS client. */
215 if (host->h_rpcclnt == NULL) {
216 struct rpc_clnt *clnt;
218 /* Bind an rpc client to this host handle (does not
219 * perform a portmapper lookup) */
220 if (!(clnt = nlm_bind_host(host))) {
224 clnt->cl_softrtry = nfssrv->client->cl_softrtry;
225 clnt->cl_intr = nfssrv->client->cl_intr;
226 clnt->cl_chatty = nfssrv->client->cl_chatty;
229 /* Keep the old signal mask */
230 spin_lock_irqsave(¤t->sighand->siglock, flags);
231 oldset = current->blocked;
233 /* If we're cleaning up locks because the process is exiting,
234 * perform the RPC call asynchronously. */
235 if ((IS_SETLK(cmd) || IS_SETLKW(cmd))
236 && fl->fl_type == F_UNLCK
237 && (current->flags & PF_EXITING)) {
238 sigfillset(¤t->blocked); /* Mask all signals */
240 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
242 call = nlmclnt_alloc_call();
247 call->a_flags = RPC_TASK_ASYNC;
249 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
250 memset(call, 0, sizeof(*call));
251 locks_init_lock(&call->a_args.lock.fl);
252 locks_init_lock(&call->a_res.lock.fl);
256 nlmclnt_locks_init_private(fl, host);
258 /* Set up the argument struct */
259 nlmclnt_setlockargs(call, fl);
261 if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
262 if (fl->fl_type != F_UNLCK) {
263 call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
264 status = nlmclnt_lock(call, fl);
266 status = nlmclnt_unlock(call, fl);
267 } else if (IS_GETLK(cmd))
268 status = nlmclnt_test(call, fl);
273 spin_lock_irqsave(¤t->sighand->siglock, flags);
274 current->blocked = oldset;
276 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
279 dprintk("lockd: clnt proc returns %d\n", status);
280 nlm_release_host(host);
283 EXPORT_SYMBOL(nlmclnt_proc);
286 * Allocate an NLM RPC call struct
289 nlmclnt_alloc_call(void)
291 struct nlm_rqst *call;
293 while (!signalled()) {
294 call = (struct nlm_rqst *) kmalloc(sizeof(struct nlm_rqst), GFP_KERNEL);
296 memset(call, 0, sizeof(*call));
297 locks_init_lock(&call->a_args.lock.fl);
298 locks_init_lock(&call->a_res.lock.fl);
301 printk("nlmclnt_alloc_call: failed, waiting for memory\n");
302 schedule_timeout_interruptible(5*HZ);
307 static int nlm_wait_on_grace(wait_queue_head_t *queue)
312 prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
314 schedule_timeout(NLMCLNT_GRACE_WAIT);
319 finish_wait(queue, &wait);
327 nlmclnt_call(struct nlm_rqst *req, u32 proc)
329 struct nlm_host *host = req->a_host;
330 struct rpc_clnt *clnt;
331 struct nlm_args *argp = &req->a_args;
332 struct nlm_res *resp = &req->a_res;
333 struct rpc_message msg = {
339 dprintk("lockd: call procedure %d on %s\n",
340 (int)proc, host->h_name);
343 if (host->h_reclaiming && !argp->reclaim)
344 goto in_grace_period;
346 /* If we have no RPC client yet, create one. */
347 if ((clnt = nlm_bind_host(host)) == NULL)
349 msg.rpc_proc = &clnt->cl_procinfo[proc];
351 /* Perform the RPC call. If an error occurs, try again */
352 if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
353 dprintk("lockd: rpc_call returned error %d\n", -status);
355 case -EPROTONOSUPPORT:
361 nlm_rebind_host(host);
365 return signalled () ? -EINTR : status;
371 if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) {
372 dprintk("lockd: server in grace period\n");
375 "lockd: spurious grace period reject?!\n");
379 if (!argp->reclaim) {
380 /* We appear to be out of the grace period */
381 wake_up_all(&host->h_gracewait);
383 dprintk("lockd: server returns status %d\n", resp->status);
384 return 0; /* Okay, call complete */
389 * The server has rebooted and appears to be in the grace
390 * period during which locks are only allowed to be
392 * We can only back off and try again later.
394 status = nlm_wait_on_grace(&host->h_gracewait);
395 } while (status == 0);
401 * Generic NLM call, async version.
403 int nlmsvc_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
405 struct nlm_host *host = req->a_host;
406 struct rpc_clnt *clnt;
407 struct rpc_message msg = {
408 .rpc_argp = &req->a_args,
409 .rpc_resp = &req->a_res,
413 dprintk("lockd: call procedure %d on %s (async)\n",
414 (int)proc, host->h_name);
416 /* If we have no RPC client yet, create one. */
417 if ((clnt = nlm_bind_host(host)) == NULL)
419 msg.rpc_proc = &clnt->cl_procinfo[proc];
421 /* bootstrap and kick off the async RPC call */
422 status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
427 static int nlmclnt_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
429 struct nlm_host *host = req->a_host;
430 struct rpc_clnt *clnt;
431 struct nlm_args *argp = &req->a_args;
432 struct nlm_res *resp = &req->a_res;
433 struct rpc_message msg = {
439 dprintk("lockd: call procedure %d on %s (async)\n",
440 (int)proc, host->h_name);
442 /* If we have no RPC client yet, create one. */
443 if ((clnt = nlm_bind_host(host)) == NULL)
445 msg.rpc_proc = &clnt->cl_procinfo[proc];
447 /* Increment host refcount */
449 /* bootstrap and kick off the async RPC call */
450 status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
452 nlm_release_host(host);
457 * TEST for the presence of a conflicting lock
460 nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
464 status = nlmclnt_call(req, NLMPROC_TEST);
465 nlmclnt_release_lockargs(req);
469 status = req->a_res.status;
470 if (status == NLM_LCK_GRANTED) {
471 fl->fl_type = F_UNLCK;
472 } if (status == NLM_LCK_DENIED) {
474 * Report the conflicting lock back to the application.
476 locks_copy_lock(fl, &req->a_res.lock.fl);
479 return nlm_stat_to_errno(req->a_res.status);
485 static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
487 memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
488 nlm_get_lockowner(new->fl_u.nfs_fl.owner);
491 static void nlmclnt_locks_release_private(struct file_lock *fl)
493 nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
497 static struct file_lock_operations nlmclnt_lock_ops = {
498 .fl_copy_lock = nlmclnt_locks_copy_lock,
499 .fl_release_private = nlmclnt_locks_release_private,
502 static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
504 BUG_ON(fl->fl_ops != NULL);
505 fl->fl_u.nfs_fl.state = 0;
506 fl->fl_u.nfs_fl.flags = 0;
507 fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
508 fl->fl_ops = &nlmclnt_lock_ops;
511 static void do_vfs_lock(struct file_lock *fl)
514 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
516 res = posix_lock_file_wait(fl->fl_file, fl);
519 res = flock_lock_file_wait(fl->fl_file, fl);
525 printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
530 * LOCK: Try to create a lock
532 * Programmer Harassment Alert
534 * When given a blocking lock request in a sync RPC call, the HPUX lockd
535 * will faithfully return LCK_BLOCKED but never cares to notify us when
536 * the lock could be granted. This way, our local process could hang
537 * around forever waiting for the callback.
539 * Solution A: Implement busy-waiting
540 * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
542 * For now I am implementing solution A, because I hate the idea of
543 * re-implementing lockd for a third time in two months. The async
544 * calls shouldn't be too hard to do, however.
546 * This is one of the lovely things about standards in the NFS area:
547 * they're so soft and squishy you can't really blame HP for doing this.
550 nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
552 struct nlm_host *host = req->a_host;
553 struct nlm_res *resp = &req->a_res;
557 if (!host->h_monitored && nsm_monitor(host) < 0) {
558 printk(KERN_NOTICE "lockd: failed to monitor %s\n",
564 if (req->a_args.block) {
565 status = nlmclnt_prepare_block(req, host, fl);
570 status = nlmclnt_call(req, NLMPROC_LOCK);
573 if (resp->status != NLM_LCK_BLOCKED)
575 /* Wait on an NLM blocking lock */
576 timeout = nlmclnt_block(req, NLMCLNT_POLL_TIMEOUT);
577 /* Did a reclaimer thread notify us of a server reboot? */
578 if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD)
580 if (resp->status != NLM_LCK_BLOCKED)
584 /* We were interrupted. Send a CANCEL request to the server
587 status = (int)timeout;
591 if (resp->status == NLM_LCK_GRANTED) {
592 fl->fl_u.nfs_fl.state = host->h_state;
593 fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
594 fl->fl_flags |= FL_SLEEP;
597 status = nlm_stat_to_errno(resp->status);
599 nlmclnt_finish_block(req);
600 /* Cancel the blocked request if it is still pending */
601 if (resp->status == NLM_LCK_BLOCKED)
602 nlmclnt_cancel(host, fl);
604 nlmclnt_release_lockargs(req);
609 * RECLAIM: Try to reclaim a lock
612 nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
614 struct nlm_rqst reqst, *req;
618 memset(req, 0, sizeof(*req));
619 locks_init_lock(&req->a_args.lock.fl);
620 locks_init_lock(&req->a_res.lock.fl);
624 /* Set up the argument struct */
625 nlmclnt_setlockargs(req, fl);
626 req->a_args.reclaim = 1;
628 if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
629 && req->a_res.status == NLM_LCK_GRANTED)
632 printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
633 "(errno %d, status %d)\n", fl->fl_pid,
634 status, req->a_res.status);
637 * FIXME: This is a serious failure. We can
639 * a. Ignore the problem
640 * b. Send the owning process some signal (Linux doesn't have
641 * SIGLOST, though...)
642 * c. Retry the operation
644 * Until someone comes up with a simple implementation
645 * for b or c, I'll choose option a.
652 * UNLOCK: remove an existing lock
655 nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
657 struct nlm_res *resp = &req->a_res;
660 /* Clean the GRANTED flag now so the lock doesn't get
661 * reclaimed while we're stuck in the unlock call. */
662 fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
664 if (req->a_flags & RPC_TASK_ASYNC) {
665 status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
666 &nlmclnt_unlock_ops);
667 /* Hrmf... Do the unlock early since locks_remove_posix()
668 * really expects us to free the lock synchronously */
671 nlmclnt_release_lockargs(req);
677 status = nlmclnt_call(req, NLMPROC_UNLOCK);
678 nlmclnt_release_lockargs(req);
683 if (resp->status == NLM_LCK_GRANTED)
686 if (resp->status != NLM_LCK_DENIED_NOLOCKS)
687 printk("lockd: unexpected unlock status: %d\n", resp->status);
689 /* What to do now? I'm out of my depth... */
694 static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
696 struct nlm_rqst *req = data;
697 int status = req->a_res.status;
699 if (RPC_ASSASSINATED(task))
702 if (task->tk_status < 0) {
703 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
706 if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
707 rpc_delay(task, NLMCLNT_GRACE_WAIT);
710 if (status != NLM_LCK_GRANTED)
711 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
713 nlm_release_host(req->a_host);
714 nlmclnt_release_lockargs(req);
718 nlm_rebind_host(req->a_host);
720 rpc_restart_call(task);
723 static const struct rpc_call_ops nlmclnt_unlock_ops = {
724 .rpc_call_done = nlmclnt_unlock_callback,
728 * Cancel a blocked lock request.
729 * We always use an async RPC call for this in order not to hang a
730 * process that has been Ctrl-C'ed.
733 nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
735 struct nlm_rqst *req;
740 /* Block all signals while setting up call */
741 spin_lock_irqsave(¤t->sighand->siglock, flags);
742 oldset = current->blocked;
743 sigfillset(¤t->blocked);
745 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
747 req = nlmclnt_alloc_call();
751 req->a_flags = RPC_TASK_ASYNC;
753 nlmclnt_setlockargs(req, fl);
755 status = nlmclnt_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops);
757 nlmclnt_release_lockargs(req);
761 spin_lock_irqsave(¤t->sighand->siglock, flags);
762 current->blocked = oldset;
764 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
769 static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
771 struct nlm_rqst *req = data;
773 if (RPC_ASSASSINATED(task))
776 if (task->tk_status < 0) {
777 dprintk("lockd: CANCEL call error %d, retrying.\n",
782 dprintk("lockd: cancel status %d (task %d)\n",
783 req->a_res.status, task->tk_pid);
785 switch (req->a_res.status) {
786 case NLM_LCK_GRANTED:
787 case NLM_LCK_DENIED_GRACE_PERIOD:
788 /* Everything's good */
790 case NLM_LCK_DENIED_NOLOCKS:
791 dprintk("lockd: CANCEL failed (server has no locks)\n");
794 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
799 nlm_release_host(req->a_host);
800 nlmclnt_release_lockargs(req);
805 nlm_rebind_host(req->a_host);
806 rpc_restart_call(task);
807 rpc_delay(task, 30 * HZ);
810 static const struct rpc_call_ops nlmclnt_cancel_ops = {
811 .rpc_call_done = nlmclnt_cancel_callback,
815 * Convert an NLM status code to a generic kernel errno
818 nlm_stat_to_errno(u32 status)
821 case NLM_LCK_GRANTED:
825 case NLM_LCK_DENIED_NOLOCKS:
826 case NLM_LCK_DENIED_GRACE_PERIOD:
828 case NLM_LCK_BLOCKED:
829 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
831 #ifdef CONFIG_LOCKD_V4
844 printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);