lockd: add code to handle deferred lock requests
Rewrite nlmsvc_lock() to use the asynchronous interface.
As with testlock, we answer nlm requests in nlmsvc_lock by first looking up
the block and then using the results we find in the block if B_QUEUED is
set, and calling vfs_lock_file() otherwise.
If this a new lock request and we get -EINPROGRESS return on a non-blocking
request then we defer the request.
Also modify nlmsvc_unlock() to call the filesystem method if appropriate.
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
index 205d8be..bf27b6c 100644
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -145,6 +145,8 @@
/* Now try to lock the file */
resp->status = nlmsvc_lock(rqstp, file, &argp->lock,
argp->block, &argp->cookie);
+ if (resp->status == nlm_drop_reply)
+ return rpc_drop_reply;
dprintk("lockd: LOCK status %d\n", ntohl(resp->status));
nlm_release_host(host);
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 0d7398e..b3efa45 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -393,17 +393,43 @@
} else
lock->fl.fl_flags &= ~FL_SLEEP;
- error = posix_lock_file(file->f_file, &lock->fl, NULL);
+ if (block->b_flags & B_QUEUED) {
+ dprintk("lockd: nlmsvc_lock deferred block %p flags %d\n",
+ block, block->b_flags);
+ if (block->b_granted) {
+ nlmsvc_unlink_block(block);
+ ret = nlm_granted;
+ goto out;
+ }
+ if (block->b_flags & B_TIMED_OUT) {
+ nlmsvc_unlink_block(block);
+ ret = nlm_lck_denied;
+ goto out;
+ }
+ ret = nlm_drop_reply;
+ goto out;
+ }
+
+ if (!wait)
+ lock->fl.fl_flags &= ~FL_SLEEP;
+ error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
lock->fl.fl_flags &= ~FL_SLEEP;
- dprintk("lockd: posix_lock_file returned %d\n", error);
-
+ dprintk("lockd: vfs_lock_file returned %d\n", error);
switch(error) {
case 0:
ret = nlm_granted;
goto out;
case -EAGAIN:
+ ret = nlm_lck_denied;
break;
+ case -EINPROGRESS:
+ if (wait)
+ break;
+ /* Filesystem lock operation is in progress
+ Add it to the queue waiting for callback */
+ ret = nlmsvc_defer_lock_rqst(rqstp, block);
+ goto out;
case -EDEADLK:
ret = nlm_deadlock;
goto out;
@@ -535,7 +561,7 @@
nlmsvc_cancel_blocked(file, lock);
lock->fl.fl_type = F_UNLCK;
- error = posix_lock_file(file->f_file, &lock->fl, NULL);
+ error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
return (error < 0)? nlm_lck_denied_nolocks : nlm_granted;
}
@@ -564,6 +590,8 @@
block = nlmsvc_lookup_block(file, lock);
mutex_unlock(&file->f_mutex);
if (block != NULL) {
+ vfs_cancel_lock(block->b_file->f_file,
+ &block->b_call->a_args.lock.fl);
status = nlmsvc_unlink_block(block);
nlmsvc_release_block(block);
}
@@ -697,14 +725,15 @@
/* Try the lock operation again */
lock->fl.fl_flags |= FL_SLEEP;
- error = posix_lock_file(file->f_file, &lock->fl, NULL);
+ error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL);
lock->fl.fl_flags &= ~FL_SLEEP;
switch (error) {
case 0:
break;
case -EAGAIN:
- dprintk("lockd: lock still blocked\n");
+ case -EINPROGRESS:
+ dprintk("lockd: lock still blocked error %d\n", error);
nlmsvc_insert_block(block, NLM_NEVER);
nlmsvc_release_block(block);
return;
diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
index 40b5cf4..9cd5c8b 100644
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -175,6 +175,8 @@
/* Now try to lock the file */
resp->status = cast_status(nlmsvc_lock(rqstp, file, &argp->lock,
argp->block, &argp->cookie));
+ if (resp->status == nlm_drop_reply)
+ return rpc_drop_reply;
dprintk("lockd: LOCK status %d\n", ntohl(resp->status));
nlm_release_host(host);
diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
index 5095708..84ebba3 100644
--- a/fs/lockd/svcsubs.c
+++ b/fs/lockd/svcsubs.c
@@ -182,7 +182,7 @@
lock.fl_type = F_UNLCK;
lock.fl_start = 0;
lock.fl_end = OFFSET_MAX;
- if (posix_lock_file(file->f_file, &lock, NULL) < 0) {
+ if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) {
printk("lockd: unlock failure in %s:%d\n",
__FILE__, __LINE__);
return 1;