f2fs: implement -o dirsync

If a mount option has dirsync, we should call checkpoint for all the directory
operations.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 6312dd2..2bee559 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -138,6 +138,9 @@
 	stat_inc_inline_inode(inode);
 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
 	return 0;
 out:
 	handle_failed_inode(inode);
@@ -164,6 +167,9 @@
 	f2fs_unlock_op(sbi);
 
 	d_instantiate(dentry, inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
 	return 0;
 out:
 	clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
@@ -235,6 +241,9 @@
 
 	/* In order to evict this inode, we set it dirty */
 	mark_inode_dirty(inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
 fail:
 	trace_f2fs_unlink_exit(inode, err);
 	return err;
@@ -268,6 +277,9 @@
 
 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
 	return err;
 out:
 	handle_failed_inode(inode);
@@ -304,6 +316,8 @@
 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);
 
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
 	return 0;
 
 out_fail:
@@ -346,8 +360,12 @@
 	f2fs_unlock_op(sbi);
 
 	alloc_nid_done(sbi, inode->i_ino);
+
 	d_instantiate(dentry, inode);
 	unlock_new_inode(inode);
+
+	if (IS_DIRSYNC(dir))
+		f2fs_sync_fs(sbi->sb, 1);
 	return 0;
 out:
 	handle_failed_inode(inode);
@@ -461,6 +479,9 @@
 	}
 
 	f2fs_unlock_op(sbi);
+
+	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+		f2fs_sync_fs(sbi->sb, 1);
 	return 0;
 
 put_out_dir:
@@ -600,6 +621,9 @@
 	update_inode_page(new_dir);
 
 	f2fs_unlock_op(sbi);
+
+	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+		f2fs_sync_fs(sbi->sb, 1);
 	return 0;
 out_undo:
 	/* Still we may fail to recover name info of f2fs_inode here */