nilfs2: move iterator to write log into segment buffer

This moves iterator to submit write requests for a series of logs into
segbuf.c, and hides nilfs_segbuf_write() and nilfs_segbuf_wait() in
the file.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

fs/nilfs2/segbuf.c

@@ -40,6 +40,11 @@ struct nilfs_write_info {
 };
 
 
+static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
+			      struct the_nilfs *nilfs);
+static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
+
+
 static struct kmem_cache *nilfs_segbuf_cachep;
 
 static void nilfs_segbuf_init_once(void *obj)
@@ -302,6 +307,19 @@ void nilfs_truncate_logs(struct list_head *logs,
 	}
 }
 
+int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
+{
+	struct nilfs_segment_buffer *segbuf;
+	int ret = 0;
+
+	list_for_each_entry(segbuf, logs, sb_list) {
+		ret = nilfs_segbuf_write(segbuf, nilfs);
+		if (ret)
+			break;
+	}
+	return ret;
+}
+
 int nilfs_wait_on_logs(struct list_head *logs)
 {
 	struct nilfs_segment_buffer *segbuf;

fs/nilfs2/segbuf.h

@@ -166,13 +166,10 @@ nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf,
 	segbuf->sb_sum.nfileblk++;
 }
 
-int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
-		       struct the_nilfs *nilfs);
-int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
-
 void nilfs_clear_logs(struct list_head *logs);
 void nilfs_truncate_logs(struct list_head *logs,
 			 struct nilfs_segment_buffer *last);
+int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs);
 int nilfs_wait_on_logs(struct list_head *logs);
 
 static inline void nilfs_destroy_logs(struct list_head *logs)

fs/nilfs2/segment.c

@@ -1764,14 +1764,9 @@ static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
 			       struct the_nilfs *nilfs)
 {
-	struct nilfs_segment_buffer *segbuf;
-	int ret = 0;
+	int ret;
 
-	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
-		ret = nilfs_segbuf_write(segbuf, nilfs);
-		if (ret)
-			break;
-	}
+	ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
 	list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
 	return ret;
 }