On Thu, 2025-05-29 at 10:10 +0100, Pádraig Brady wrote: > On 28/05/2025 16:14, Gael Donval wrote: > > Dear list, > > > > We've unearth an odd behaviour in cp: `cp --preserve=xattr` tries to copy > > both attributes of the chattr kind and extended attributes of the getfattr > > kind with apparently no way to disable either one of them (it's all or > > nothing). This is problematic in tools like mkosi where > > non-filesystem-specific xattributes need to be preserved whilst FS-specific > > attributes must be discarded for cross-filesystem support. > > > > I have added a MWE at the end of this email after my signature: it creates > > two raw partitions as files (one as XFS, one as BTRFS), mounts them in > > local folders and creates 3 files in the BTRFS partitions later altered > > before copy. > > > > Referring to the script, we think there should be an option to copy files > > foo (no-attr), bar (setfattr) and baz (chattr), keeping the setfattr's > > xattr and discarding chattr's attr. Looking at the code, it seems like cp > > eventually defers the actual attribute copying libattr, which seems to > > handle both, but separately (which is what we want). > > > > Would it make sense to add a separate `attr` preserve value for the chattr > > case and keep `xattr` for getfattr case? > > I've not looked in detail at your case, > but it's worth noting that /etc/xattr.conf > gives the facility to skip copying certain xattrs. > Does that suffice to handle your issue?
As far as I can tell, xattr.conf cannot be used to ignore normal file attributes (as opposed to extended attributes), can it? We need a way to copy extended attributes without copying normal file attributes. Thanks, Gaël > > thanks, > Pádraig
