ncpfs: add bdi backing to mount session

This ensures that dirty data gets flushed properly.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index cf98da1..fa33851 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -526,10 +526,15 @@
 	sb->s_blocksize_bits = 10;
 	sb->s_magic = NCP_SUPER_MAGIC;
 	sb->s_op = &ncp_sops;
+	sb->s_bdi = &server->bdi;
 
 	server = NCP_SBP(sb);
 	memset(server, 0, sizeof(*server));
 
+	error = bdi_setup_and_register(&server->bdi, "ncpfs", BDI_CAP_MAP_COPY);
+	if (error)
+		goto out_bdi;
+
 	server->ncp_filp = ncp_filp;
 	server->ncp_sock = sock;
 	
@@ -719,6 +724,8 @@
 	if (server->info_filp)
 		fput(server->info_filp);
 out_fput:
+	bdi_destroy(&server->bdi);
+out_bdi:
 	/* 23/12/1998 Marcin Dalecki <dalecki@cs.net.pl>:
 	 * 
 	 * The previously used put_filp(ncp_filp); was bogous, since
@@ -756,6 +763,7 @@
 	kill_pid(server->m.wdog_pid, SIGTERM, 1);
 	put_pid(server->m.wdog_pid);
 
+	bdi_destroy(&server->bdi);
 	kfree(server->priv.data);
 	kfree(server->auth.object_name);
 	vfree(server->rxbuf);