On 3/8/25 18:02, Rick Macklem wrote:
First off, I cross posted because I don't think many read freebsd-arch@.
There seems to be a nice market for Solaris style extended attributes.
Hold on a moment.
I have been following this discussion now for a while and I am trying to
figure who wants this? Why? Is this a "make work" project wherein a pile
of code and testing will needed? Where the word "pile" may mean years.
Since ZFS is already wired for them, adding the basics is pretty
straightforward. I am not suggesting that they should replace the
current FreeBSD extended attributes.
Well if you decide to go into NFS with xattr then you may as well dig
into UFS with xattr also. Perhaps that would be insane however once you
deal with ACL handling in tools like tar and ls then you will need to
ponder UFS also. That means output similar to Solaris /usr/xpg4/bin/ls
like so :
The following example shows how to display compact ACL
information on a ZFS directory.
% ls -dV test.dir
drwxr-xr-x 2 marks staff 2 Mar 14 10:17 test.dir
owner@:--------------:------:deny
owner@:rwxp---A-W-Co-:------:allow
group@:-w-p----------:------:deny
group@:r-x-----------:------:allow
everyone@:-w-p---A-W-Co-:------:deny
everyone@:r-x---a-R-c--s:------:allow
The following example illustrates the ls -v behavior when
listing ACL information on a UFS file.
$ ls -v file.3
-rw-r--r-- 1 root root 2703 Mar 14 10:59 file.3
0:user::rw-
1:group::r-- #effective:r--
2:mask:r--
3:other:r--
I see considerable differences between the FreeBSD base ls and Solaris
ls which does handle ACL data in both UFS and ZFS. Does this need to
be dragged onto the table along with every other file handling tool
and system call? I see a tarpit ( no pun intended ) this opens up.
For those not familiar with them (I am not very familiar myself;-),
a Solaris style extended attribute is in a directory that hangs off
the file object and the entries in the directory (the attributes) can
be manipulated with open/read/write/lseek just like a regular file.
(They can be as large as a regular file, but there is no atomicity
guarantees.)
I just, today, shutdown my last Solaris server which was a Fujitsu
SPARC64 machine and it was draining power and making heat for a number
of years in my life. Certainly it was using ZFS but not the ZFS that we
can use or "zfs send" anywhere. The botched up stuff that is totally not
compatible with OpenZFS of any flavour. This means that I had to do a
blunt force medieval tarball backup. Nothing else would ever be usable
for recovery.
Never in the many many years of using Solaris with ZFS have I felt the
need to drag in xattr's on people. Not once in two decades. Pretty sure
I did some very early testing within the OpenSolaris project and can not
recall the desperate need thereafter.
So who wants this? Why? Is there some atom-splitting world changing
reason that the extended attributes are needed in FreeBSD?
--
--
Dennis Clarke
RISC-V/SPARC/PPC/ARM/CISC
UNIX and Linux spoken
ps: Jörg Schilling wrote a very xattr aware TAR in his schilytools
https://github.com/clausecker/schilytools
It is cross platform aware and already in ports as "star".
https://cgit.freebsd.org/ports/tree/archivers/star/pkg-descr
Being fast is a matter of opinion but I used it to backup my
Fujitsu SPARC64 server today and the stats over 1Gbit NFSv3 are :
pluto# tail -16 hubble_sparc64.star.log
a 1564 -rw-r--r-- 1 root/root May 2 04:08 2024 var/dt/Xerrors
a 5 -rw-r--r-- 1 root/root May 2 04:08 2024 var/dt/Xpid
a 0 drwxr-xr-x 2 root/root May 2 04:08 2024 vol/
a 0 drwxr-xr-x 2 root/root May 5 22:31 2024 z/
star: Missing links to 'proc/183/fd/3'.
star: Missing links to 'proc/108/object/a.out'.
star: fifo had 20090580 puts 45730806 gets.
star: fifo was 1092 times empty and 1548 times full.
star: fifo held 268441600 bytes max, size was 268441600 bytes
star: 45730806 blocks + 0 bytes (total of 468283453440 bytes =
457308060.00k).
star: Total time 8539.200sec (53553 kBytes/sec)
star: The following problems occurred during archive processing:
star: Cannot: stat 2, open 0, read/write 42, chdir 0, iconv 349.
star: Size changed 34.
star: Missing links 2, Name too long 0, File too big 0, Not dumped 1.
star: Processed all possible files, despite earlier errors.
So yeah, it works and you can trust it.
