For purposes of data deduplication and data synchronisation, it would be a powerful tool to expose file data checksums. Since eg BTRFS uses the crc32c algorithm [1], it's possible to compute the file's overall CRC from the accumulation of the CRCs from all it's extents' CRCs. For now, exposing this via an IOCTL may be sufficient, though any ideas for introducing it in a more standard way? (it's a pity that when stat64 was introduced, reserved fields weren't added) Thanks, Daniel [1] http://www.research.ibm.com/haifa/satran/ips/Vince-Luben-crc32c-01.pdf -- Daniel J Blueman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
