update exfat from current head

Change-Id: I7d93474296612fda1dde23f6e8690668d6880e27
diff --git a/exfat/libexfat/cluster.c b/exfat/libexfat/cluster.c
index 2215636..80e3792 100644
--- a/exfat/libexfat/cluster.c
+++ b/exfat/libexfat/cluster.c
@@ -3,7 +3,7 @@
 	exFAT file system implementation library.
 
 	Free exFAT implementation.
-	Copyright (C) 2010-2013  Andrew Nayenko
+	Copyright (C) 2010-2014  Andrew Nayenko
 
 	This program is free software; you can redistribute it and/or modify
 	it under the terms of the GNU General Public License as published by
@@ -83,9 +83,9 @@
 		return cluster + 1;
 	fat_offset = s2o(ef, le32_to_cpu(ef->sb->fat_sector_start))
 		+ cluster * sizeof(cluster_t);
-	/* FIXME handle I/O error */
 	if (exfat_pread(ef->dev, &next, sizeof(next), fat_offset) < 0)
-		exfat_bug("failed to read the next cluster after %#x", cluster);
+		return EXFAT_CLUSTER_BAD; /* the caller should handle this and print
+		                             appropriate error message */
 	return le32_to_cpu(next);
 }
 
@@ -136,8 +136,23 @@
 	return EXFAT_CLUSTER_END;
 }
 
+static int flush_nodes(struct exfat* ef, struct exfat_node* node)
+{
+	struct exfat_node* p;
+
+	for (p = node->child; p != NULL; p = p->next)
+	{
+		int rc = flush_nodes(ef, p);
+		if (rc != 0)
+			return rc;
+	}
+	return exfat_flush_node(ef, node);
+}
+
 int exfat_flush(struct exfat* ef)
 {
+	int rc = flush_nodes(ef, ef->root);
+
 	if (ef->cmap.dirty)
 	{
 		if (exfat_pwrite(ef->dev, ef->cmap.chunk,
@@ -149,7 +164,8 @@
 		}
 		ef->cmap.dirty = false;
 	}
-	return 0;
+
+	return rc;
 }
 
 static bool set_next_cluster(const struct exfat* ef, bool contiguous,
@@ -316,6 +332,7 @@
 	{
 		previous = node->start_cluster;
 		node->start_cluster = EXFAT_CLUSTER_FREE;
+		node->flags |= EXFAT_ATTRIB_DIRTY;
 	}
 	node->fptr_index = 0;
 	node->fptr_cluster = node->start_cluster;