+/*
+ * helper function for fat_flush_inodes. This writes both the inode
+ * and the file data blocks, waiting for in flight data blocks before
+ * the start of the call. It does not wait for any io started
+ * during the call
+ */
+static int writeback_inode(struct inode *inode)
+{
+
+ int ret;
+ struct address_space *mapping = inode->i_mapping;
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_NONE,
+ .nr_to_write = 0,
+ };
+ /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
+ * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
+ * and filemap_fdatawrite is used for the data blocks
+ */
+ ret = sync_inode(inode, &wbc);
+ if (!ret)
+ ret = filemap_fdatawrite(mapping);
+ return ret;
+}
+
+/*
+ * write data and metadata corresponding to i1 and i2. The io is
+ * started but we do not wait for any of it to finish.
+ *
+ * filemap_flush is used for the block device, so if there is a dirty
+ * page for a block already in flight, we will not wait and start the
+ * io over again
+ */
+int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
+{
+ int ret = 0;
+ if (!MSDOS_SB(sb)->options.flush)
+ return 0;
+ if (i1)
+ ret = writeback_inode(i1);
+ if (!ret && i2)
+ ret = writeback_inode(i2);
+ if (!ret) {
+ struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
+ ret = filemap_flush(mapping);
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(fat_flush_inodes);