> > Recovery after a power fail > > --------------------------- > > > > If the dm-protected device was not cleanly shut down, then we need to > > examine all of the checksum blocks in the Active Area. For each > > checksum block in the AA, the checksums for all of their data blocks > > should machine either the checksum found in the AA, or the checksum > > found in the checksum block in the checksum group. > > ... and if the checksum of the block matches BOTH the checksum in the AA > and the checksum in the checksum group (because of checksum function > collision), you don't know which 4-bit nibble belongs to the data in the > block. Though, I realize that you could avoid this problem by selecting the appropriate checksum function - that never results in collision if the 4-bit nibble differs. Mikulas -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
