ncpfs: add bdi backing to mount session

This ensures that dirty data gets flushed properly.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

fs/ncpfs/inode.c

@@ -526,10 +526,15 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 	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 @@ out_fput2:
 	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 @@ static void ncp_put_super(struct super_block *sb)
 	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);

include/linux/ncp_fs_sb.h

@@ -12,6 +12,7 @@
 #include <linux/ncp_mount.h>
 #include <linux/net.h>
 #include <linux/mutex.h>
+#include <linux/backing-dev.h>
 
 #ifdef __KERNEL__
 
@@ -127,6 +128,7 @@ struct ncp_server {
 		size_t len;
 		__u8 data[128];
 	} unexpected_packet;
+	struct backing_dev_info bdi;
 };
 
 extern void ncp_tcp_rcv_proc(struct work_struct *work);