lockd: handle test_lock deferrals
Rewrite nlmsvc_testlock() to use the new asynchronous interface: instead of
immediately doing a posix_test_lock(), we first look for a matching block.
If the subsequent test_lock returns anything other than -EINPROGRESS, we
then remove the block we've found and return the results.
If it returns -EINPROGRESS, then we defer the lock request.
In the case where the block we find in the first step has B_QUEUED set,
we bypass the vfs_test_lock entirely, instead using the block to decide how
to respond:
with nlm_lck_denied if B_TIMED_OUT is set.
with nlm_granted if B_GOT_CALLBACK is set.
by dropping if neither B_TIMED_OUT nor B_GOT_CALLBACK is set
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 a1bccad..205d8be 100644
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -100,6 +100,8 @@
/* Now check for conflicting locks */
resp->status = nlmsvc_testlock(rqstp, file, &argp->lock, &resp->lock, &resp->cookie);
+ if (resp->status == nlm_drop_reply)
+ return rpc_drop_reply;
dprintk("lockd: TEST4 status %d\n", ntohl(resp->status));
nlm_release_host(host);
