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;
228 /* Keep the old signal mask */
229 spin_lock_irqsave(¤t->sighand->siglock, flags);
230 oldset = current->blocked;
232 /* If we're cleaning up locks because the process is exiting,
233 * perform the RPC call asynchronously. */
234 if ((IS_SETLK(cmd) || IS_SETLKW(cmd))
235 && fl->fl_type == F_UNLCK
236 && (current->flags & PF_EXITING)) {
237 sigfillset(¤t->blocked); /* Mask all signals */
239 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
241 call = nlmclnt_alloc_call();
246 call->a_flags = RPC_TASK_ASYNC;
248 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
249 memset(call, 0, sizeof(*call));
250 locks_init_lock(&call->a_args.lock.fl);
251 locks_init_lock(&call->a_res.lock.fl);
255 nlmclnt_locks_init_private(fl, host);
257 /* Set up the argument struct */
258 nlmclnt_setlockargs(call, fl);
260 if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
261 if (fl->fl_type != F_UNLCK) {
262 call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
263 status = nlmclnt_lock(call, fl);
265 status = nlmclnt_unlock(call, fl);
266 } else if (IS_GETLK(cmd))
267 status = nlmclnt_test(call, fl);
272 spin_lock_irqsave(¤t->sighand->siglock, flags);
273 current->blocked = oldset;
275 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
278 dprintk("lockd: clnt proc returns %d\n", status);
279 nlm_release_host(host);
282 EXPORT_SYMBOL(nlmclnt_proc);
285 * Allocate an NLM RPC call struct
288 nlmclnt_alloc_call(void)
290 struct nlm_rqst *call;
292 while (!signalled()) {
293 call = (struct nlm_rqst *) kmalloc(sizeof(struct nlm_rqst), GFP_KERNEL);
295 memset(call, 0, sizeof(*call));
296 locks_init_lock(&call->a_args.lock.fl);
297 locks_init_lock(&call->a_res.lock.fl);
300 printk("nlmclnt_alloc_call: failed, waiting for memory\n");
301 schedule_timeout_interruptible(5*HZ);
306 static int nlm_wait_on_grace(wait_queue_head_t *queue)
311 prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
313 schedule_timeout(NLMCLNT_GRACE_WAIT);
318 finish_wait(queue, &wait);
326 nlmclnt_call(struct nlm_rqst *req, u32 proc)
328 struct nlm_host *host = req->a_host;
329 struct rpc_clnt *clnt;
330 struct nlm_args *argp = &req->a_args;
331 struct nlm_res *resp = &req->a_res;
332 struct rpc_message msg = {
338 dprintk("lockd: call procedure %d on %s\n",
339 (int)proc, host->h_name);
342 if (host->h_reclaiming && !argp->reclaim)
343 goto in_grace_period;
345 /* If we have no RPC client yet, create one. */
346 if ((clnt = nlm_bind_host(host)) == NULL)
348 msg.rpc_proc = &clnt->cl_procinfo[proc];
350 /* Perform the RPC call. If an error occurs, try again */
351 if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
352 dprintk("lockd: rpc_call returned error %d\n", -status);
354 case -EPROTONOSUPPORT:
360 nlm_rebind_host(host);
364 return signalled () ? -EINTR : status;
370 if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD) {
371 dprintk("lockd: server in grace period\n");
374 "lockd: spurious grace period reject?!\n");
378 if (!argp->reclaim) {
379 /* We appear to be out of the grace period */
380 wake_up_all(&host->h_gracewait);
382 dprintk("lockd: server returns status %d\n", resp->status);
383 return 0; /* Okay, call complete */
388 * The server has rebooted and appears to be in the grace
389 * period during which locks are only allowed to be
391 * We can only back off and try again later.
393 status = nlm_wait_on_grace(&host->h_gracewait);
394 } while (status == 0);
400 * Generic NLM call, async version.
402 int nlmsvc_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
404 struct nlm_host *host = req->a_host;
405 struct rpc_clnt *clnt;
406 struct rpc_message msg = {
407 .rpc_argp = &req->a_args,
408 .rpc_resp = &req->a_res,
412 dprintk("lockd: call procedure %d on %s (async)\n",
413 (int)proc, host->h_name);
415 /* If we have no RPC client yet, create one. */
416 if ((clnt = nlm_bind_host(host)) == NULL)
418 msg.rpc_proc = &clnt->cl_procinfo[proc];
420 /* bootstrap and kick off the async RPC call */
421 status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
426 static int nlmclnt_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
428 struct nlm_host *host = req->a_host;
429 struct rpc_clnt *clnt;
430 struct nlm_args *argp = &req->a_args;
431 struct nlm_res *resp = &req->a_res;
432 struct rpc_message msg = {
438 dprintk("lockd: call procedure %d on %s (async)\n",
439 (int)proc, host->h_name);
441 /* If we have no RPC client yet, create one. */
442 if ((clnt = nlm_bind_host(host)) == NULL)
444 msg.rpc_proc = &clnt->cl_procinfo[proc];
446 /* Increment host refcount */
448 /* bootstrap and kick off the async RPC call */
449 status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
451 nlm_release_host(host);
456 * TEST for the presence of a conflicting lock
459 nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
463 status = nlmclnt_call(req, NLMPROC_TEST);
464 nlmclnt_release_lockargs(req);
468 status = req->a_res.status;
469 if (status == NLM_LCK_GRANTED) {
470 fl->fl_type = F_UNLCK;
471 } if (status == NLM_LCK_DENIED) {
473 * Report the conflicting lock back to the application.
475 locks_copy_lock(fl, &req->a_res.lock.fl);
478 return nlm_stat_to_errno(req->a_res.status);
484 static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
486 memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
487 nlm_get_lockowner(new->fl_u.nfs_fl.owner);
490 static void nlmclnt_locks_release_private(struct file_lock *fl)
492 nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
496 static struct file_lock_operations nlmclnt_lock_ops = {
497 .fl_copy_lock = nlmclnt_locks_copy_lock,
498 .fl_release_private = nlmclnt_locks_release_private,
501 static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
503 BUG_ON(fl->fl_ops != NULL);
504 fl->fl_u.nfs_fl.state = 0;
505 fl->fl_u.nfs_fl.flags = 0;
506 fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
507 fl->fl_ops = &nlmclnt_lock_ops;
510 static void do_vfs_lock(struct file_lock *fl)
513 switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
515 res = posix_lock_file_wait(fl->fl_file, fl);
518 res = flock_lock_file_wait(fl->fl_file, fl);
524 printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
529 * LOCK: Try to create a lock
531 * Programmer Harassment Alert
533 * When given a blocking lock request in a sync RPC call, the HPUX lockd
534 * will faithfully return LCK_BLOCKED but never cares to notify us when
535 * the lock could be granted. This way, our local process could hang
536 * around forever waiting for the callback.
538 * Solution A: Implement busy-waiting
539 * Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
541 * For now I am implementing solution A, because I hate the idea of
542 * re-implementing lockd for a third time in two months. The async
543 * calls shouldn't be too hard to do, however.
545 * This is one of the lovely things about standards in the NFS area:
546 * they're so soft and squishy you can't really blame HP for doing this.
549 nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
551 struct nlm_host *host = req->a_host;
552 struct nlm_res *resp = &req->a_res;
556 if (!host->h_monitored && nsm_monitor(host) < 0) {
557 printk(KERN_NOTICE "lockd: failed to monitor %s\n",
563 if (req->a_args.block) {
564 status = nlmclnt_prepare_block(req, host, fl);
569 status = nlmclnt_call(req, NLMPROC_LOCK);
572 if (resp->status != NLM_LCK_BLOCKED)
574 /* Wait on an NLM blocking lock */
575 timeout = nlmclnt_block(req, NLMCLNT_POLL_TIMEOUT);
576 /* Did a reclaimer thread notify us of a server reboot? */
577 if (resp->status == NLM_LCK_DENIED_GRACE_PERIOD)
579 if (resp->status != NLM_LCK_BLOCKED)
583 /* We were interrupted. Send a CANCEL request to the server
586 status = (int)timeout;
590 if (resp->status == NLM_LCK_GRANTED) {
591 fl->fl_u.nfs_fl.state = host->h_state;
592 fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
593 fl->fl_flags |= FL_SLEEP;
596 status = nlm_stat_to_errno(resp->status);
598 nlmclnt_finish_block(req);
599 /* Cancel the blocked request if it is still pending */
600 if (resp->status == NLM_LCK_BLOCKED)
601 nlmclnt_cancel(host, fl);
603 nlmclnt_release_lockargs(req);
608 * RECLAIM: Try to reclaim a lock
611 nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
613 struct nlm_rqst reqst, *req;
617 memset(req, 0, sizeof(*req));
618 locks_init_lock(&req->a_args.lock.fl);
619 locks_init_lock(&req->a_res.lock.fl);
623 /* Set up the argument struct */
624 nlmclnt_setlockargs(req, fl);
625 req->a_args.reclaim = 1;
627 if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
628 && req->a_res.status == NLM_LCK_GRANTED)
631 printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
632 "(errno %d, status %d)\n", fl->fl_pid,
633 status, req->a_res.status);
636 * FIXME: This is a serious failure. We can
638 * a. Ignore the problem
639 * b. Send the owning process some signal (Linux doesn't have
640 * SIGLOST, though...)
641 * c. Retry the operation
643 * Until someone comes up with a simple implementation
644 * for b or c, I'll choose option a.
651 * UNLOCK: remove an existing lock
654 nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
656 struct nlm_res *resp = &req->a_res;
659 /* Clean the GRANTED flag now so the lock doesn't get
660 * reclaimed while we're stuck in the unlock call. */
661 fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
663 if (req->a_flags & RPC_TASK_ASYNC) {
664 status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
665 &nlmclnt_unlock_ops);
666 /* Hrmf... Do the unlock early since locks_remove_posix()
667 * really expects us to free the lock synchronously */
670 nlmclnt_release_lockargs(req);
676 status = nlmclnt_call(req, NLMPROC_UNLOCK);
677 nlmclnt_release_lockargs(req);
682 if (resp->status == NLM_LCK_GRANTED)
685 if (resp->status != NLM_LCK_DENIED_NOLOCKS)
686 printk("lockd: unexpected unlock status: %d\n", resp->status);
688 /* What to do now? I'm out of my depth... */
693 static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
695 struct nlm_rqst *req = data;
696 int status = req->a_res.status;
698 if (RPC_ASSASSINATED(task))
701 if (task->tk_status < 0) {
702 dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
705 if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
706 rpc_delay(task, NLMCLNT_GRACE_WAIT);
709 if (status != NLM_LCK_GRANTED)
710 printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
712 nlm_release_host(req->a_host);
713 nlmclnt_release_lockargs(req);
717 nlm_rebind_host(req->a_host);
719 rpc_restart_call(task);
722 static const struct rpc_call_ops nlmclnt_unlock_ops = {
723 .rpc_call_done = nlmclnt_unlock_callback,
727 * Cancel a blocked lock request.
728 * We always use an async RPC call for this in order not to hang a
729 * process that has been Ctrl-C'ed.
732 nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
734 struct nlm_rqst *req;
739 /* Block all signals while setting up call */
740 spin_lock_irqsave(¤t->sighand->siglock, flags);
741 oldset = current->blocked;
742 sigfillset(¤t->blocked);
744 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
746 req = nlmclnt_alloc_call();
750 req->a_flags = RPC_TASK_ASYNC;
752 nlmclnt_setlockargs(req, fl);
754 status = nlmclnt_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops);
756 nlmclnt_release_lockargs(req);
760 spin_lock_irqsave(¤t->sighand->siglock, flags);
761 current->blocked = oldset;
763 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
768 static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
770 struct nlm_rqst *req = data;
772 if (RPC_ASSASSINATED(task))
775 if (task->tk_status < 0) {
776 dprintk("lockd: CANCEL call error %d, retrying.\n",
781 dprintk("lockd: cancel status %d (task %d)\n",
782 req->a_res.status, task->tk_pid);
784 switch (req->a_res.status) {
785 case NLM_LCK_GRANTED:
786 case NLM_LCK_DENIED_GRACE_PERIOD:
787 /* Everything's good */
789 case NLM_LCK_DENIED_NOLOCKS:
790 dprintk("lockd: CANCEL failed (server has no locks)\n");
793 printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
798 nlm_release_host(req->a_host);
799 nlmclnt_release_lockargs(req);
804 nlm_rebind_host(req->a_host);
805 rpc_restart_call(task);
806 rpc_delay(task, 30 * HZ);
809 static const struct rpc_call_ops nlmclnt_cancel_ops = {
810 .rpc_call_done = nlmclnt_cancel_callback,
814 * Convert an NLM status code to a generic kernel errno
817 nlm_stat_to_errno(u32 status)
820 case NLM_LCK_GRANTED:
824 case NLM_LCK_DENIED_NOLOCKS:
825 case NLM_LCK_DENIED_GRACE_PERIOD:
827 case NLM_LCK_BLOCKED:
828 printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
830 #ifdef CONFIG_LOCKD_V4
843 printk(KERN_NOTICE "lockd: unexpected server status %d\n", status);