Hello all,
Sort of on this topic has anyone have a transfer tool like rsync or mmxcp that 
transfers the NFSv4 ACL’s correctly?
Thanks
Matt

From: gpfsug-discuss <[email protected]> on behalf of Anh Dao 
<[email protected]>
Date: Wednesday, September 7, 2022 at 3:48 PM
To: [email protected] <[email protected]>
Subject: Re: [gpfsug-discuss] NF4 ACLs (Joshua Taylor)
In-Reply-To: 
caghstwimcszfse0jmqamoole9ybgbd_v1thsjawuan1rk4c...@mail.gmail.com<mailto:caghstwimcszfse0jmqamoole9ybgbd_v1thsjawuan1rk4c...@mail.gmail.com>

In Linux, chown has the following note:
man 2 chown
“Only a privileged process (Linux: one with the CAP_CHOWN capability) may 
change the owner of a file.
  The owner of a file may change the group of the file to any group of which 
that owner is a member.
 A privileged process (Linux: with CAP_CHOWN) may change the group arbitrarily.”

Scale now adds NFSv4 ACLs, and the CHOWN permission is basically an additional 
restriction on top of what Linux does. Since Scale is only invoked after Linux 
has perform its checks (chown_ok 
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/fs/attr.c?h=v5.19.7<https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kernel.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fstable%2Flinux.git%2Ftree%2Ffs%2Fattr.c%3Fh%3Dv5.19.7&data=05%7C01%7Cmweil%40wustl.edu%7Cb25ddd2794eb41a6f86708da911247d5%7C4ccca3b571cd4e6d974b4d9beb96c6d6%7C0%7C0%7C637981804950298764%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=EIItawyb55fEtyeHgOR2Tk4x9Ooja4cCHJbqVFdDJzQ%3D&reserved=0>),
 it cannot overcome the restrictions in place in the Linux VFS.

Regarding the wrapper mentioned, the admin (root) is certainly able to 
implement such setuid wrapper, but they should be very careful on the security 
aspects of doing so. This seems risky for Scale to implement such program.

Regards,
Anh Dao
IBM Spectrum Scale
Software Developer
[email protected]


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