NFS: nfs_readpage_async() needs to be accessible as a fallback for local caching

nfs_readpage_async() needs to be non-static so that it can be used as a
fallback for the local on-disk caching should an EIO crop up when reading the
cache.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>

fs/nfs/read.c

@@ -111,8 +111,8 @@ static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
 	}
 }
 
-static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
-		struct page *page)
+int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
+		       struct page *page)
 {
 	LIST_HEAD(one_request);
 	struct nfs_page	*new;

include/linux/nfs_fs.h

@@ -516,6 +516,8 @@ extern int  nfs_readpages(struct file *, struct address_space *,
 		struct list_head *, unsigned);
 extern int  nfs_readpage_result(struct rpc_task *, struct nfs_read_data *);
 extern void nfs_readdata_release(void *data);
+extern int  nfs_readpage_async(struct nfs_open_context *, struct inode *,
+			       struct page *);
 
 /*
  * Allocate nfs_read_data structures