On 2016/9/20 10:55, Jaegeuk Kim wrote: > Previously, we used cp_version only to detect recoverable dnodes. > In order to avoid same garbage cp_version, we needed to truncate the next > dnode during checkpoint, resulting in additional discard or data write. > If we can distinguish this by using crc in addition to cp_version, we can > remove this overhead. > > There is backward compatibility concern where it changes node_footer layout. > But, it only affects the direct nodes written after the last checkpoint. > We simply expect that user would change kernel versions back and forth after > stable checkpoint. Seems with new released v4.8 f2fs, old image with recoverable data could be mounted successfully, but meanwhile all fsynced data which needs to be recovered will be lost w/o any hints? Could we release a new version mkfs paired with new kernel module, so we can tag image as a new layout one, then new kernel module can recognize the image layout and adjust version suited comparing method with old or new image? Thanks, -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
