[PATCH] nfs: Always try and release an NFS file lock, even after receiving a SIGKILL

[David Jeffery <djeffery@redhat.com>]

If a task holding an NFS file lock is killed with SIGKILL, it can
error out of do_unlk without ever trying to release the lock on
the server. This triggers the WARN in locks_remove_file(), while
also leaving the lock still claimed on the NFS server.  The file's
lock state is left out of sync between client and server, requiring
a restart of one or the other in order to release this ghost lock
on the file.

do_unlk() should continue on and tell the server to release the
lock, even if nfs_iocounter_wait() reports an error do to SIGKILL.

Signed-off-by: David Jeffery <djeffery@redhat.com>

---
 file.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 4042ff5..1b09243 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -750,10 +750,8 @@ do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
 
 	l_ctx = nfs_get_lock_context(nfs_file_open_context(filp));
 	if (!IS_ERR(l_ctx)) {
-		status = nfs_iocounter_wait(&l_ctx->io_count);
+		nfs_iocounter_wait(&l_ctx->io_count);
 		nfs_put_lock_context(l_ctx);
-		if (status < 0)
-			return status;
 	}
 
 	/* NOTE: special case