GFP_NOFS is not enough, since swap traffic is IO, hence fall back to GFP_NOIO.

this comment imply turn on GFP_NOIO, but the code is s/NOFS/NOIO/. why?

 struct nfs_write_data *nfs_commitdata_alloc(void)
 {
-	struct nfs_write_data *p = kmem_cache_alloc(nfs_wdata_cachep, GFP_NOFS);
+	struct nfs_write_data *p = kmem_cache_alloc(nfs_wdata_cachep, GFP_NOIO);