From 1688f2775f1468ed5be0b01bd8518f2d7144b808 Mon Sep 17 00:00:00 2001
From: relan <relan@users.noreply.github.com>
Date: Mon, 22 Jul 2013 18:04:26 +0000
Subject: [PATCH] Implement fsync() and fsyncdir().

---
 fuse/main.c        | 11 +++++++++++
 libexfat/cluster.c | 11 +++++++----
 libexfat/exfat.h   |  2 +-
 libexfat/node.c    |  9 +++++----
 4 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/fuse/main.c b/fuse/main.c
index 6e16f3a..4bf553e 100644
--- a/fuse/main.c
+++ b/fuse/main.c
@@ -154,6 +154,15 @@ static int fuse_exfat_release(const char* path, struct fuse_file_info* fi)
 	return 0;
 }
 
+static int fuse_exfat_fsync(const char* path, int datasync,
+		struct fuse_file_info *fi)
+{
+	exfat_debug("[%s] %s", __func__, path);
+	exfat_flush_node(&ef, get_node(fi));
+	exfat_flush(&ef);
+	return exfat_fsync(ef.dev);
+}
+
 static int fuse_exfat_read(const char* path, char* buffer, size_t size,
 		off_t offset, struct fuse_file_info* fi)
 {
@@ -315,6 +324,8 @@ static struct fuse_operations fuse_exfat_ops =
 	.readdir	= fuse_exfat_readdir,
 	.open		= fuse_exfat_open,
 	.release	= fuse_exfat_release,
+	.fsync		= fuse_exfat_fsync,
+	.fsyncdir	= fuse_exfat_fsync,
 	.read		= fuse_exfat_read,
 	.write		= fuse_exfat_write,
 	.unlink		= fuse_exfat_unlink,
diff --git a/libexfat/cluster.c b/libexfat/cluster.c
index d020d36..5a13d23 100644
--- a/libexfat/cluster.c
+++ b/libexfat/cluster.c
@@ -129,11 +129,14 @@ static cluster_t find_bit_and_set(uint8_t* bitmap, size_t start, size_t end)
 	return EXFAT_CLUSTER_END;
 }
 
-void exfat_flush_cmap(struct exfat* ef)
+void exfat_flush(struct exfat* ef)
 {
-	exfat_pwrite(ef->dev, ef->cmap.chunk, (ef->cmap.chunk_size + 7) / 8,
-			exfat_c2o(ef, ef->cmap.start_cluster));
-	ef->cmap.dirty = false;
+	if (ef->cmap.dirty)
+	{
+		exfat_pwrite(ef->dev, ef->cmap.chunk, (ef->cmap.chunk_size + 7) / 8,
+				exfat_c2o(ef, ef->cmap.start_cluster));
+		ef->cmap.dirty = false;
+	}
 }
 
 static void set_next_cluster(const struct exfat* ef, bool contiguous,
diff --git a/libexfat/exfat.h b/libexfat/exfat.h
index e2539b9..f7825d3 100644
--- a/libexfat/exfat.h
+++ b/libexfat/exfat.h
@@ -162,7 +162,7 @@ cluster_t exfat_next_cluster(const struct exfat* ef,
 		const struct exfat_node* node, cluster_t cluster);
 cluster_t exfat_advance_cluster(const struct exfat* ef,
 		struct exfat_node* node, uint32_t count);
-void exfat_flush_cmap(struct exfat* ef);
+void exfat_flush(struct exfat* ef);
 int exfat_truncate(struct exfat* ef, struct exfat_node* node, uint64_t size,
 		bool erase);
 uint32_t exfat_count_free_clusters(const struct exfat* ef);
diff --git a/libexfat/node.c b/libexfat/node.c
index 0c6800d..58ec3db 100644
--- a/libexfat/node.c
+++ b/libexfat/node.c
@@ -53,16 +53,14 @@ void exfat_put_node(struct exfat* ef, struct exfat_node* node)
 
 	if (node->references == 0)
 	{
-		if (node->flags & EXFAT_ATTRIB_DIRTY)
-			exfat_flush_node(ef, node);
+		exfat_flush_node(ef, node);
 		if (node->flags & EXFAT_ATTRIB_UNLINKED)
 		{
 			/* free all clusters and node structure itself */
 			exfat_truncate(ef, node, 0, true);
 			free(node);
 		}
-		if (ef->cmap.dirty)
-			exfat_flush_cmap(ef);
+		exfat_flush(ef);
 	}
 }
 
@@ -526,6 +524,9 @@ void exfat_flush_node(struct exfat* ef, struct exfat_node* node)
 	struct exfat_entry_meta1 meta1;
 	struct exfat_entry_meta2 meta2;
 
+	if (!(node->flags & EXFAT_ATTRIB_DIRTY))
+		return; /* no need to flush */
+
 	if (ef->ro)
 		exfat_bug("unable to flush node to read-only FS");
 
-- 
2.11.0