On 09/21/2012 10:01 PM, Jiří Zárevúcky wrote: > On 21 September 2012 21:06, Jakub Jermar <[email protected]> wrote: >> [...] >> >> The respective files are: >> >> uspace/lib/ext4/libext4_crc.c >> uspace/lib/ext4/libext4_hash.c >> >> Suggestions for remedy? >> >> Jakub >> > > Are these just checksum/hashing algorithms? > (I'm intentionally not looking inside the files, just in case.) > If so, those should be easy to reimplement based on their original > publication or another source.
The first is a version of a 16-bit CRC. Interestingly, there is another, different implementation of a 16-bit CRC in UDF. Not sure if they will compute the same results from the same input or not. The second case looks more complicated as the file system can use several possible algorithms for computing a hash of a string. The individual hash algorithms are referred to as: EXT4_HASH_VERSION_LEGACY_UNSIGNED EXT4_HASH_VERSION_LEGACY EXT4_HASH_VERSION_HALF_MD4_UNSIGNED EXT4_HASH_VERSION_HALF_MD4 EXT4_HASH_VERSION_TEA_UNSIGNED EXT4_HASH_VERSION_TEA It seems to me like both of this functionality is only needed when the directory search uses directory index. Jakub _______________________________________________ HelenOS-devel mailing list [email protected] http://lists.modry.cz/cgi-bin/listinfo/helenos-devel
