ceph: switch some GFP_NOFS memory allocation to GFP_KERNEL

GFP_NOFS memory allocation is required for page writeback path.
But there is no need to use GFP_NOFS in syscall path and readpage
path

Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 8d73fe9..6aa07af 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1668,7 +1668,8 @@
 
 	order = get_order(size * num_entries);
 	while (order >= 0) {
-		rinfo->dir_in = (void*)__get_free_pages(GFP_NOFS | __GFP_NOWARN,
+		rinfo->dir_in = (void*)__get_free_pages(GFP_KERNEL |
+							__GFP_NOWARN,
 							order);
 		if (rinfo->dir_in)
 			break;