On Sun, 2013-08-18 at 16:43 +0100, Pádraig Brady wrote: > You definitely need the fsync before doing the fiemap. > We saw this on certain file systems including ext4 when adding > fiemap support (efficient reading of holes) to cp. > This is a bug in the fiemap interface IMHO in that it returns > fairly useless data unless FIEMAP_FLAG_SYNC is specified. > For a general utility like cp, we couldn't sync each file before copying > (even only large files), so we restrict fiemap usage to files that > have a different disk usage than apparent size and so probably contain holes. I see, thanks a lot for suggestion. Just to make it clear, this is more like working around file-system bugs, which, as I guess, were present in early days of FIEMAP. I'll look into adding FIEMAP_FLAG_SYNC to Fiemap.py in bmap-tools, thanks! -- Best Regards, Artem Bityutskiy -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
