Hi Jaegeuk, 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. With it, tests/generic/050 of fstest will fail: setting device read-only mounting filesystem that needs recovery on a read-only device: mount: SCRATCH_DEV is write-protected, mounting read-only -mount: cannot mount SCRATCH_DEV read-only unmounting read-only filesystem -umount: SCRATCH_DEV: not mounted mounting filesystem with -o norecovery on a read-only device: Could you have a look at it? 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