> > `cp -a` offers that flexibility (good) but also silently drops > > everything if any intermediary does not support xattrs (very bad). The > > latter is relatively common on distributed FS but could also happen > > depending on vendor/admin choices. > > > > > > The current approach of setting up xattr copy rules in /etc/xattr.conf > > is unwieldy: > > > > 1. it does not work for non-root users; > > 2. and does not allow for any call-specific adjustment. > > > > Setting up a container so that a normal user can setup a scoped local > > /etc/xattr.conf tailored to their use, to make a specific tree copy > > checking for the existence of a minimal set of supported xattrs is a > > bit convoluted. > > > > Any alternative suggestion would be good. > So you're suggesting supporting something like --xattrs-include=... and > --xattrs-exclude. > Looking now, I see that tar supports those exact options. > Also rsync support xattr filtering though its --filter rules. > This does give more control, though also less general control > as one would need to config the xattrs for each particular system / call. > Also given other archiving tools support this already, > I'm not sure it's warranted in cp.
The only problem with rsync is that it doesn't support reflinks. Otherwise it would be perfect (there is a series of patch that exist since 2021 but no one ever merged them in main). Gaël > > cheers, > Pádraig
