Index: uspace/lib/fs/libfs.c
===================================================================
--- uspace/lib/fs/libfs.c	(revision 3fb0fec747a4716bb4fb5082c52a39854a2e11a6)
+++ uspace/lib/fs/libfs.c	(revision 7eb0fed89435279831404b521cf4bb3b30d02cd6)
@@ -93,6 +93,7 @@
 	rc = vfs_out_ops->mounted(devmap_handle, opts, &index, &size, &lnkcnt);
 
-	if (rc == EOK)	// FIXME: size is 64-bit
-		async_answer_3(rid, EOK, index, size, lnkcnt);
+	if (rc == EOK)
+		async_answer_4(rid, EOK, index, LOWER32(size), UPPER32(size),
+		    lnkcnt);
 	else
 		async_answer_0(rid, rc);
@@ -434,6 +435,6 @@
 	 * Do not release the FS node so that it stays in memory.
 	 */
-	async_answer_3(rid, rc, IPC_GET_ARG1(answer), IPC_GET_ARG2(answer),
-	    IPC_GET_ARG3(answer));
+	async_answer_4(rid, rc, IPC_GET_ARG1(answer), IPC_GET_ARG2(answer),
+	    IPC_GET_ARG3(answer), IPC_GET_ARG4(answer));
 }
 
Index: uspace/srv/vfs/vfs_ops.c
===================================================================
--- uspace/srv/vfs/vfs_ops.c	(revision 3fb0fec747a4716bb4fb5082c52a39854a2e11a6)
+++ uspace/srv/vfs/vfs_ops.c	(revision 7eb0fed89435279831404b521cf4bb3b30d02cd6)
@@ -76,5 +76,5 @@
 	vfs_node_t *mr_node;
 	fs_index_t rindex;
-	size_t rsize;
+	aoff64_t rsize;
 	unsigned rlnkcnt;
 	async_exch_t *exch;
@@ -146,6 +146,6 @@
 
 			rindex = (fs_index_t) IPC_GET_ARG1(answer);
-			rsize = (size_t) IPC_GET_ARG2(answer);
-			rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
+			rsize = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(answer), IPC_GET_ARG3(answer));
+			rlnkcnt = (unsigned) IPC_GET_ARG4(answer);
 			
 			mr_res.triplet.fs_handle = fs_handle;
@@ -229,6 +229,7 @@
 	if (rc == EOK) {
 		rindex = (fs_index_t) IPC_GET_ARG1(answer);
-		rsize = (size_t) IPC_GET_ARG2(answer);
-		rlnkcnt = (unsigned) IPC_GET_ARG3(answer);
+		rsize = (aoff64_t) MERGE_LOUP32(IPC_GET_ARG2(answer),
+		    IPC_GET_ARG3(answer));
+		rlnkcnt = (unsigned) IPC_GET_ARG4(answer);
 		
 		mr_res.triplet.fs_handle = fs_handle;