2 * linux/fs/lockd/svclock.c
4 * Handling of server-side locks, mostly of the blocked variety.
5 * This is the ugliest part of lockd because we tread on very thin ice.
6 * GRANT and CANCEL calls may get stuck, meet in mid-flight, etc.
7 * IMNSHO introducing the grant callback into the NLM protocol was one
8 * of the worst ideas Sun ever had. Except maybe for the idea of doing
9 * NFS file locking at all.
11 * I'm trying hard to avoid race conditions by protecting most accesses
12 * to a file's list of blocked locks through a semaphore. The global
13 * list of blocked locks is not protected in this fashion however.
14 * Therefore, some functions (such as the RPC callback for the async grant
15 * call) move blocked locks towards the head of the list *while some other
16 * process might be traversing it*. This should not be a problem in
17 * practice, because this will only cause functions traversing the list
18 * to visit some blocks twice.
20 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
23 #include <linux/types.h>
24 #include <linux/errno.h>
25 #include <linux/kernel.h>
26 #include <linux/sched.h>
27 #include <linux/smp_lock.h>
28 #include <linux/sunrpc/clnt.h>
29 #include <linux/sunrpc/svc.h>
30 #include <linux/lockd/nlm.h>
31 #include <linux/lockd/lockd.h>
32 #include <linux/kthread.h>
34 #define NLMDBG_FACILITY NLMDBG_SVCLOCK
36 #ifdef CONFIG_LOCKD_V4
37 #define nlm_deadlock nlm4_deadlock
39 #define nlm_deadlock nlm_lck_denied
42 static void nlmsvc_release_block(struct nlm_block *block);
43 static void nlmsvc_insert_block(struct nlm_block *block, unsigned long);
44 static void nlmsvc_remove_block(struct nlm_block *block);
46 static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock);
47 static void nlmsvc_freegrantargs(struct nlm_rqst *call);
48 static const struct rpc_call_ops nlmsvc_grant_ops;
51 * The list of blocked locks to retry
53 static LIST_HEAD(nlm_blocked);
56 * Insert a blocked lock into the global list
59 nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
62 struct list_head *pos;
64 dprintk("lockd: nlmsvc_insert_block(%p, %ld)\n", block, when);
65 if (list_empty(&block->b_list)) {
66 kref_get(&block->b_count);
68 list_del_init(&block->b_list);
72 if (when != NLM_NEVER) {
73 if ((when += jiffies) == NLM_NEVER)
75 list_for_each(pos, &nlm_blocked) {
76 b = list_entry(pos, struct nlm_block, b_list);
77 if (time_after(b->b_when,when) || b->b_when == NLM_NEVER)
80 /* On normal exit from the loop, pos == &nlm_blocked,
81 * so we will be adding to the end of the list - good
85 list_add_tail(&block->b_list, pos);
90 * Remove a block from the global list
93 nlmsvc_remove_block(struct nlm_block *block)
95 if (!list_empty(&block->b_list)) {
96 list_del_init(&block->b_list);
97 nlmsvc_release_block(block);
102 * Find a block for a given lock
104 static struct nlm_block *
105 nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock)
107 struct nlm_block *block;
108 struct file_lock *fl;
110 dprintk("lockd: nlmsvc_lookup_block f=%p pd=%d %Ld-%Ld ty=%d\n",
111 file, lock->fl.fl_pid,
112 (long long)lock->fl.fl_start,
113 (long long)lock->fl.fl_end, lock->fl.fl_type);
114 list_for_each_entry(block, &nlm_blocked, b_list) {
115 fl = &block->b_call->a_args.lock.fl;
116 dprintk("lockd: check f=%p pd=%d %Ld-%Ld ty=%d cookie=%s\n",
117 block->b_file, fl->fl_pid,
118 (long long)fl->fl_start,
119 (long long)fl->fl_end, fl->fl_type,
120 nlmdbg_cookie2a(&block->b_call->a_args.cookie));
121 if (block->b_file == file && nlm_compare_locks(fl, &lock->fl)) {
122 kref_get(&block->b_count);
130 static inline int nlm_cookie_match(struct nlm_cookie *a, struct nlm_cookie *b)
134 if(memcmp(a->data,b->data,a->len))
140 * Find a block with a given NLM cookie.
142 static inline struct nlm_block *
143 nlmsvc_find_block(struct nlm_cookie *cookie)
145 struct nlm_block *block;
147 list_for_each_entry(block, &nlm_blocked, b_list) {
148 if (nlm_cookie_match(&block->b_call->a_args.cookie,cookie))
155 dprintk("nlmsvc_find_block(%s): block=%p\n", nlmdbg_cookie2a(cookie), block);
156 kref_get(&block->b_count);
161 * Create a block and initialize it.
163 * Note: we explicitly set the cookie of the grant reply to that of
164 * the blocked lock request. The spec explicitly mentions that the client
165 * should _not_ rely on the callback containing the same cookie as the
166 * request, but (as I found out later) that's because some implementations
167 * do just this. Never mind the standards comittees, they support our
168 * logging industries.
170 * 10 years later: I hope we can safely ignore these old and broken
171 * clients by now. Let's fix this so we can uniquely identify an incoming
172 * GRANTED_RES message by cookie, without having to rely on the client's IP
175 static struct nlm_block *
176 nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host,
177 struct nlm_file *file, struct nlm_lock *lock,
178 struct nlm_cookie *cookie)
180 struct nlm_block *block;
181 struct nlm_rqst *call = NULL;
183 call = nlm_alloc_call(host);
187 /* Allocate memory for block, and initialize arguments */
188 block = kzalloc(sizeof(*block), GFP_KERNEL);
191 kref_init(&block->b_count);
192 INIT_LIST_HEAD(&block->b_list);
193 INIT_LIST_HEAD(&block->b_flist);
195 if (!nlmsvc_setgrantargs(call, lock))
198 /* Set notifier function for VFS, and init args */
199 call->a_args.lock.fl.fl_flags |= FL_SLEEP;
200 call->a_args.lock.fl.fl_lmops = &nlmsvc_lock_operations;
201 nlmclnt_next_cookie(&call->a_args.cookie);
203 dprintk("lockd: created block %p...\n", block);
205 /* Create and initialize the block */
206 block->b_daemon = rqstp->rq_server;
207 block->b_host = host;
208 block->b_file = file;
212 /* Add to file's list of blocks */
213 list_add(&block->b_flist, &file->f_blocks);
215 /* Set up RPC arguments for callback */
216 block->b_call = call;
217 call->a_flags = RPC_TASK_ASYNC;
218 call->a_block = block;
225 nlm_release_call(call);
230 * Delete a block. If the lock was cancelled or the grant callback
231 * failed, unlock is set to 1.
232 * It is the caller's responsibility to check whether the file
233 * can be closed hereafter.
235 static int nlmsvc_unlink_block(struct nlm_block *block)
238 dprintk("lockd: unlinking block %p...\n", block);
240 /* Remove block from list */
241 status = posix_unblock_lock(block->b_file->f_file, &block->b_call->a_args.lock.fl);
242 nlmsvc_remove_block(block);
246 static void nlmsvc_free_block(struct kref *kref)
248 struct nlm_block *block = container_of(kref, struct nlm_block, b_count);
249 struct nlm_file *file = block->b_file;
251 dprintk("lockd: freeing block %p...\n", block);
253 /* Remove block from file's list of blocks */
254 mutex_lock(&file->f_mutex);
255 list_del_init(&block->b_flist);
256 mutex_unlock(&file->f_mutex);
258 nlmsvc_freegrantargs(block->b_call);
259 nlm_release_call(block->b_call);
260 nlm_release_file(block->b_file);
265 static void nlmsvc_release_block(struct nlm_block *block)
268 kref_put(&block->b_count, nlmsvc_free_block);
272 * Loop over all blocks and delete blocks held by
275 void nlmsvc_traverse_blocks(struct nlm_host *host,
276 struct nlm_file *file,
277 nlm_host_match_fn_t match)
279 struct nlm_block *block, *next;
282 mutex_lock(&file->f_mutex);
283 list_for_each_entry_safe(block, next, &file->f_blocks, b_flist) {
284 if (!match(block->b_host, host))
286 /* Do not destroy blocks that are not on
287 * the global retry list - why? */
288 if (list_empty(&block->b_list))
290 kref_get(&block->b_count);
291 mutex_unlock(&file->f_mutex);
292 nlmsvc_unlink_block(block);
293 nlmsvc_release_block(block);
296 mutex_unlock(&file->f_mutex);
300 * Initialize arguments for GRANTED call. The nlm_rqst structure
301 * has been cleared already.
303 static int nlmsvc_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
305 locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
306 memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
307 call->a_args.lock.caller = utsname()->nodename;
308 call->a_args.lock.oh.len = lock->oh.len;
310 /* set default data area */
311 call->a_args.lock.oh.data = call->a_owner;
312 call->a_args.lock.svid = lock->fl.fl_pid;
314 if (lock->oh.len > NLMCLNT_OHSIZE) {
315 void *data = kmalloc(lock->oh.len, GFP_KERNEL);
318 call->a_args.lock.oh.data = (u8 *) data;
321 memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
325 static void nlmsvc_freegrantargs(struct nlm_rqst *call)
327 if (call->a_args.lock.oh.data != call->a_owner)
328 kfree(call->a_args.lock.oh.data);
332 * Deferred lock request handling for non-blocking lock
335 nlmsvc_defer_lock_rqst(struct svc_rqst *rqstp, struct nlm_block *block)
337 __be32 status = nlm_lck_denied_nolocks;
339 block->b_flags |= B_QUEUED;
341 nlmsvc_insert_block(block, NLM_TIMEOUT);
343 block->b_cache_req = &rqstp->rq_chandle;
344 if (rqstp->rq_chandle.defer) {
345 block->b_deferred_req =
346 rqstp->rq_chandle.defer(block->b_cache_req);
347 if (block->b_deferred_req != NULL)
348 status = nlm_drop_reply;
350 dprintk("lockd: nlmsvc_defer_lock_rqst block %p flags %d status %d\n",
351 block, block->b_flags, ntohl(status));
357 * Attempt to establish a lock, and if it can't be granted, block it
361 nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
362 struct nlm_lock *lock, int wait, struct nlm_cookie *cookie)
364 struct nlm_block *block = NULL;
365 struct nlm_host *host;
369 dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n",
370 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
371 file->f_file->f_path.dentry->d_inode->i_ino,
372 lock->fl.fl_type, lock->fl.fl_pid,
373 (long long)lock->fl.fl_start,
374 (long long)lock->fl.fl_end,
377 /* Create host handle for callback */
378 host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
380 return nlm_lck_denied_nolocks;
382 /* Lock file against concurrent access */
383 mutex_lock(&file->f_mutex);
384 /* Get existing block (in case client is busy-waiting)
385 * or create new block
387 block = nlmsvc_lookup_block(file, lock);
389 block = nlmsvc_create_block(rqstp, nlm_get_host(host), file,
391 ret = nlm_lck_denied_nolocks;
394 lock = &block->b_call->a_args.lock;
396 lock->fl.fl_flags &= ~FL_SLEEP;
398 if (block->b_flags & B_QUEUED) {
399 dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n",
400 block, block->b_flags);
401 if (block->b_granted) {
402 nlmsvc_unlink_block(block);
406 if (block->b_flags & B_TIMED_OUT) {
407 nlmsvc_unlink_block(block);
408 ret = nlm_lck_denied;
411 ret = nlm_drop_reply;
416 lock->fl.fl_flags &= ~FL_SLEEP;
417 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
418 lock->fl.fl_flags &= ~FL_SLEEP;
420 dprintk("lockd: vfs_lock_file returned %d\n", error);
426 ret = nlm_lck_denied;
431 /* Filesystem lock operation is in progress
432 Add it to the queue waiting for callback */
433 ret = nlmsvc_defer_lock_rqst(rqstp, block);
438 default: /* includes ENOLCK */
439 ret = nlm_lck_denied_nolocks;
443 ret = nlm_lck_denied;
447 ret = nlm_lck_blocked;
449 /* Append to list of blocked */
450 nlmsvc_insert_block(block, NLM_NEVER);
452 mutex_unlock(&file->f_mutex);
453 nlmsvc_release_block(block);
454 nlm_release_host(host);
455 dprintk("lockd: nlmsvc_lock returned %u\n", ret);
460 * Test for presence of a conflicting lock.
463 nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
464 struct nlm_lock *lock, struct nlm_lock *conflock,
465 struct nlm_cookie *cookie)
467 struct nlm_block *block = NULL;
471 dprintk("lockd: nlmsvc_testlock(%s/%ld, ty=%d, %Ld-%Ld)\n",
472 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
473 file->f_file->f_path.dentry->d_inode->i_ino,
475 (long long)lock->fl.fl_start,
476 (long long)lock->fl.fl_end);
478 /* Get existing block (in case client is busy-waiting) */
479 block = nlmsvc_lookup_block(file, lock);
482 struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
483 struct nlm_host *host;
487 /* Create host handle for callback */
488 host = nlmsvc_lookup_host(rqstp, lock->caller, lock->len);
491 return nlm_lck_denied_nolocks;
493 block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
500 if (block->b_flags & B_QUEUED) {
501 dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n",
502 block, block->b_flags, block->b_fl);
503 if (block->b_flags & B_TIMED_OUT) {
504 nlmsvc_unlink_block(block);
505 ret = nlm_lck_denied;
508 if (block->b_flags & B_GOT_CALLBACK) {
509 nlmsvc_unlink_block(block);
510 if (block->b_fl != NULL
511 && block->b_fl->fl_type != F_UNLCK) {
512 lock->fl = *block->b_fl;
519 ret = nlm_drop_reply;
523 error = vfs_test_lock(file->f_file, &lock->fl);
524 if (error == -EINPROGRESS) {
525 ret = nlmsvc_defer_lock_rqst(rqstp, block);
529 ret = nlm_lck_denied_nolocks;
532 if (lock->fl.fl_type == F_UNLCK) {
538 dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
539 lock->fl.fl_type, (long long)lock->fl.fl_start,
540 (long long)lock->fl.fl_end);
541 conflock->caller = "somehost"; /* FIXME */
542 conflock->len = strlen(conflock->caller);
543 conflock->oh.len = 0; /* don't return OH info */
544 conflock->svid = lock->fl.fl_pid;
545 conflock->fl.fl_type = lock->fl.fl_type;
546 conflock->fl.fl_start = lock->fl.fl_start;
547 conflock->fl.fl_end = lock->fl.fl_end;
548 ret = nlm_lck_denied;
551 nlmsvc_release_block(block);
557 * This implies a CANCEL call: We send a GRANT_MSG, the client replies
558 * with a GRANT_RES call which gets lost, and calls UNLOCK immediately
559 * afterwards. In this case the block will still be there, and hence
563 nlmsvc_unlock(struct nlm_file *file, struct nlm_lock *lock)
567 dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n",
568 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
569 file->f_file->f_path.dentry->d_inode->i_ino,
571 (long long)lock->fl.fl_start,
572 (long long)lock->fl.fl_end);
574 /* First, cancel any lock that might be there */
575 nlmsvc_cancel_blocked(file, lock);
577 lock->fl.fl_type = F_UNLCK;
578 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
580 return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;
584 * Cancel a previously blocked request.
586 * A cancel request always overrides any grant that may currently
588 * The calling procedure must check whether the file can be closed.
591 nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
593 struct nlm_block *block;
596 dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n",
597 file->f_file->f_path.dentry->d_inode->i_sb->s_id,
598 file->f_file->f_path.dentry->d_inode->i_ino,
600 (long long)lock->fl.fl_start,
601 (long long)lock->fl.fl_end);
603 mutex_lock(&file->f_mutex);
604 block = nlmsvc_lookup_block(file, lock);
605 mutex_unlock(&file->f_mutex);
607 vfs_cancel_lock(block->b_file->f_file,
608 &block->b_call->a_args.lock.fl);
609 status = nlmsvc_unlink_block(block);
610 nlmsvc_release_block(block);
612 return status ? nlm_lck_denied : nlm_granted;
616 * This is a callback from the filesystem for VFS file lock requests.
617 * It will be used if fl_grant is defined and the filesystem can not
618 * respond to the request immediately.
619 * For GETLK request it will copy the reply to the nlm_block.
620 * For SETLK or SETLKW request it will get the local posix lock.
621 * In all cases it will move the block to the head of nlm_blocked q where
622 * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the
623 * deferred rpc for GETLK and SETLK.
626 nlmsvc_update_deferred_block(struct nlm_block *block, struct file_lock *conf,
629 block->b_flags |= B_GOT_CALLBACK;
631 block->b_granted = 1;
633 block->b_flags |= B_TIMED_OUT;
636 locks_copy_lock(block->b_fl, conf);
640 static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
643 struct nlm_block *block;
647 list_for_each_entry(block, &nlm_blocked, b_list) {
648 if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
649 dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n",
650 block, block->b_flags);
651 if (block->b_flags & B_QUEUED) {
652 if (block->b_flags & B_TIMED_OUT) {
656 nlmsvc_update_deferred_block(block, conf, result);
657 } else if (result == 0)
658 block->b_granted = 1;
660 nlmsvc_insert_block(block, 0);
661 svc_wake_up(block->b_daemon);
668 printk(KERN_WARNING "lockd: grant for unknown block\n");
673 * Unblock a blocked lock request. This is a callback invoked from the
674 * VFS layer when a lock on which we blocked is removed.
676 * This function doesn't grant the blocked lock instantly, but rather moves
677 * the block to the head of nlm_blocked where it can be picked up by lockd.
680 nlmsvc_notify_blocked(struct file_lock *fl)
682 struct nlm_block *block;
684 dprintk("lockd: VFS unblock notification for block %p\n", fl);
685 list_for_each_entry(block, &nlm_blocked, b_list) {
686 if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
687 nlmsvc_insert_block(block, 0);
688 svc_wake_up(block->b_daemon);
693 printk(KERN_WARNING "lockd: notification for unknown block!\n");
696 static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2)
698 return fl1->fl_owner == fl2->fl_owner && fl1->fl_pid == fl2->fl_pid;
701 struct lock_manager_operations nlmsvc_lock_operations = {
702 .fl_compare_owner = nlmsvc_same_owner,
703 .fl_notify = nlmsvc_notify_blocked,
704 .fl_grant = nlmsvc_grant_deferred,
708 * Try to claim a lock that was previously blocked.
710 * Note that we use both the RPC_GRANTED_MSG call _and_ an async
711 * RPC thread when notifying the client. This seems like overkill...
713 * - we don't want to use a synchronous RPC thread, otherwise
714 * we might find ourselves hanging on a dead portmapper.
715 * - Some lockd implementations (e.g. HP) don't react to
716 * RPC_GRANTED calls; they seem to insist on RPC_GRANTED_MSG calls.
719 nlmsvc_grant_blocked(struct nlm_block *block)
721 struct nlm_file *file = block->b_file;
722 struct nlm_lock *lock = &block->b_call->a_args.lock;
725 dprintk("lockd: grant blocked lock %p\n", block);
727 kref_get(&block->b_count);
729 /* Unlink block request from list */
730 nlmsvc_unlink_block(block);
732 /* If b_granted is true this means we've been here before.
733 * Just retry the grant callback, possibly refreshing the RPC
735 if (block->b_granted) {
736 nlm_rebind_host(block->b_host);
740 /* Try the lock operation again */
741 lock->fl.fl_flags |= FL_SLEEP;
742 error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
743 lock->fl.fl_flags &= ~FL_SLEEP;
750 dprintk("lockd: lock still blocked error %d\n", error);
751 nlmsvc_insert_block(block, NLM_NEVER);
752 nlmsvc_release_block(block);
755 printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
756 -error, __FUNCTION__);
757 nlmsvc_insert_block(block, 10 * HZ);
758 nlmsvc_release_block(block);
763 /* Lock was granted by VFS. */
764 dprintk("lockd: GRANTing blocked lock.\n");
765 block->b_granted = 1;
767 /* keep block on the list, but don't reattempt until the RPC
768 * completes or the submission fails
770 nlmsvc_insert_block(block, NLM_NEVER);
772 /* Call the client -- use a soft RPC task since nlmsvc_retry_blocked
773 * will queue up a new one if this one times out
775 error = nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG,
778 /* RPC submission failed, wait a bit and retry */
780 nlmsvc_insert_block(block, 10 * HZ);
784 * This is the callback from the RPC layer when the NLM_GRANTED_MSG
785 * RPC call has succeeded or timed out.
786 * Like all RPC callbacks, it is invoked by the rpciod process, so it
787 * better not sleep. Therefore, we put the blocked lock on the nlm_blocked
788 * chain once more in order to have it removed by lockd itself (which can
789 * then sleep on the file semaphore without disrupting e.g. the nfs client).
791 static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
793 struct nlm_rqst *call = data;
794 struct nlm_block *block = call->a_block;
795 unsigned long timeout;
797 dprintk("lockd: GRANT_MSG RPC callback\n");
799 /* if the block is not on a list at this point then it has
800 * been invalidated. Don't try to requeue it.
802 * FIXME: it's possible that the block is removed from the list
803 * after this check but before the nlmsvc_insert_block. In that
804 * case it will be added back. Perhaps we need better locking
807 if (list_empty(&block->b_list))
810 /* Technically, we should down the file semaphore here. Since we
811 * move the block towards the head of the queue only, no harm
812 * can be done, though. */
813 if (task->tk_status < 0) {
814 /* RPC error: Re-insert for retransmission */
817 /* Call was successful, now wait for client callback */
820 nlmsvc_insert_block(block, timeout);
821 svc_wake_up(block->b_daemon);
824 static void nlmsvc_grant_release(void *data)
826 struct nlm_rqst *call = data;
828 nlmsvc_release_block(call->a_block);
831 static const struct rpc_call_ops nlmsvc_grant_ops = {
832 .rpc_call_done = nlmsvc_grant_callback,
833 .rpc_release = nlmsvc_grant_release,
837 * We received a GRANT_RES callback. Try to find the corresponding
841 nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status)
843 struct nlm_block *block;
845 dprintk("grant_reply: looking for cookie %x, s=%d \n",
846 *(unsigned int *)(cookie->data), status);
847 if (!(block = nlmsvc_find_block(cookie)))
851 if (status == nlm_lck_denied_grace_period) {
852 /* Try again in a couple of seconds */
853 nlmsvc_insert_block(block, 10 * HZ);
855 /* Lock is now held by client, or has been rejected.
856 * In both cases, the block should be removed. */
857 nlmsvc_unlink_block(block);
860 nlmsvc_release_block(block);
863 /* Helper function to handle retry of a deferred block.
864 * If it is a blocking lock, call grant_blocked.
865 * For a non-blocking lock or test lock, revisit the request.
868 retry_deferred_block(struct nlm_block *block)
870 if (!(block->b_flags & B_GOT_CALLBACK))
871 block->b_flags |= B_TIMED_OUT;
872 nlmsvc_insert_block(block, NLM_TIMEOUT);
873 dprintk("revisit block %p flags %d\n", block, block->b_flags);
874 if (block->b_deferred_req) {
875 block->b_deferred_req->revisit(block->b_deferred_req, 0);
876 block->b_deferred_req = NULL;
881 * Retry all blocked locks that have been notified. This is where lockd
882 * picks up locks that can be granted, or grant notifications that must
886 nlmsvc_retry_blocked(void)
888 unsigned long timeout = MAX_SCHEDULE_TIMEOUT;
889 struct nlm_block *block;
891 while (!list_empty(&nlm_blocked) && !kthread_should_stop()) {
892 block = list_entry(nlm_blocked.next, struct nlm_block, b_list);
894 if (block->b_when == NLM_NEVER)
896 if (time_after(block->b_when,jiffies)) {
897 timeout = block->b_when - jiffies;
901 dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n",
902 block, block->b_when);
903 if (block->b_flags & B_QUEUED) {
904 dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n",
905 block, block->b_granted, block->b_flags);
906 retry_deferred_block(block);
908 nlmsvc_grant_blocked(block);