On Wed, 26 Nov 2014 16:00:23 -0800 Robert White <rwh...@pobox.com> wrote:
> Uh... you may _still_ have no checksums on any of those data extents. > They are not going to come back until you write them to a normal file > with a normal copy. So you may be lacking most of the data validation > features of this filesystem. Well, this FS is coming from being Ext4 for years, so it's not worse off now than it was before. And anyways the main feature that I wanted were snapshots. > You might want to go experiment. Make another new subvol (or at least a > directory in a directory/root/subvol that never had the +C attribute > set) and see if you can cp --reflink any of these files into that > subdirectory without repeating the +C trick. Ha, indeed I can't. Maybe there should be a way to generate checksums without rewriting files, just via reading them, then calculating and writing checksum to metadata. > Clearing NODATACOW does _not_ clear NODATASUM (at least not on a > non-empty file) as near as I can tell, so that directory hierarchy and > its subsequent snapshots is likely "less safe" than you think. The nodatasum flag also isn't accessible via chattr, is it? -- With respect, Roman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
