f2fs: introduce f2fs_commit_super

This patch introduces f2fs_commit_super to write updated superblock.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index b2dd1b01f076..85841687b40a 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -966,6 +966,30 @@ retry:
 	return 0;
 }
 
+int f2fs_commit_super(struct f2fs_sb_info *sbi)
+{
+	struct buffer_head *sbh = sbi->raw_super_buf;
+	sector_t block = sbh->b_blocknr;
+	int err;
+
+	/* write back-up superblock first */
+	sbh->b_blocknr = block ? 0 : 1;
+	mark_buffer_dirty(sbh);
+	err = sync_dirty_buffer(sbh);
+
+	sbh->b_blocknr = block;
+	if (err)
+		goto out;
+
+	/* write current valid superblock */
+	mark_buffer_dirty(sbh);
+	err = sync_dirty_buffer(sbh);
+out:
+	clear_buffer_write_io_error(sbh);
+	set_buffer_uptodate(sbh);
+	return err;
+}
+
 static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct f2fs_sb_info *sbi;