ext4: fix ZERO_RANGE test failure in data journalling

xfstests generic/091 is failing when mounting ext4 with data=journal.
I think that this regression is same problem that occurred prior to collapse
range issue. So ZERO RANGE also need to call ext4_force_commit as
collapse range.

Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/extents.c

@@ -4741,6 +4741,13 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 	if (!S_ISREG(inode->i_mode))
 		return -EINVAL;
 
+	/* Call ext4_force_commit to flush all data in case of data=journal. */
+	if (ext4_should_journal_data(inode)) {
+		ret = ext4_force_commit(inode->i_sb);
+		if (ret)
+			return ret;
+	}
+
 	/*
 	 * Write out all dirty pages to avoid race conditions
 	 * Then release them.