On Thu, Jul 10, 2025 at 10:55 AM Konstantin Belousov <kostik...@gmail.com> wrote: > > On Thu, Jul 10, 2025 at 06:59:35AM -0700, Rick Macklem wrote: > > I've done a series of commits to main to add support for > > Solaris style extended attributes (which I called named attributes, > > which is the NFSv4 term for them). > > > > ZFS is currently the only local file system that will support them > > and only if the ZFS property "xattr" is set to "dir". > > > > If "zfs set xattr=dir <volume>" is done before any user namespace > > extended attributes are created for files via extattr(2), I think > > everything makes sense. > > --> There is one set of extended attributes that are visible through > > both extattr(2) and named_attribute(7). > > > > However, if extattr(2) is used to create user namespace extended > > attributes when "xattr=sa" and then "xattr" is set to "dir", these > > extended attributes are only visible to extattr(2) and not > > named_attribute(7). > > --> I will note that you can use tar(1) to copy the files and then the > > extended attributes become visible to named_attribute(7). > > I do not see any way to avoid this, but it should at least be documented. > > > > So, where do you think I should document this? > > - I could put it in named_attribute(7) as an additional case where > > the two extended attribute system call mechanisms cannot be > > used. (I was hesitant, since this is ZFS specific). > > Does this sound ok, or is there somewhere better to put it? > > (zfsprops(7) is another possibility, since it already documents > > "sa" and "dir" values for the "xattr" property.) > > I do not see why not put it to named_attribute(7) page. We do not have a > ban on adding important fs-specific notes in the generic documentation. > More, I think it is a proper place to document the details instead of > spreading them into corners. > > BTW, would you consider adding named attrs support to tmpfs? > I believe it is useful for tmpfs to be on par with the union of > all features of our local filesystems. I'll take a look at tmpfs someday. Probably not in time for 15.0.
Thanks for the comments, rick >
