[Gluster-devel] Question regarding to gluster and vfs

[Amar Tumballi]

On Thu, Aug 17, 2017 at 1:21 PM, Raghavendra Talur <rtalur at redhat.com>
wrote:

> On Wed, Aug 16, 2017 at 5:52 PM, Ilan Schwarts <ilan84 at gmail.com> wrote:
> > Hi,
> > So this is a bit odd case.
> > I have created 2 servers nodes (running CentOS 7.3)
> > From Client machine (CentOS 7.2) I mount to one of the nodes (nfs) using:
> > [root at CentOS7286-64 mnt]#  mount -t nfs
> > L137B-GlusterFS-Node1.L137B-root.com:/volume1 /mnt/glustervianfs/
> >
> > When i created (touch) a file over the NFS:
> > From Client Machine:
> > [revivo at CentOS7286-64 glustervianfs]$ touch nfs3file
> > [revivo at CentOS7286-64 glustervianfs]$ id revivo
> > uid=2021(revivo) gid=2020(maccabi) groups=2020(maccabi),10(wheel)
> >
> > On Server machine:
> > I monitor the file operations at VFS kernel level.
> > I receive 1 event of file create, and 2 events of set attribute changes.
> > What I see is that root creates the file (uid/gid of 0)
> > And then root (also) use chown and chgrp to set security (attribute)
> > of the new file.
> >
> > When i go to the glutser volume itself and ls -la,i do see the
> > *correct* (2021 - revivo /2020 - revivo) uid/gid:
> > [root at L137B-GlusterFS-Node1 volume1]# ls -lia
> > total 24
> > 11 drwxrwxrwx.  3 revivo maccabi 4096 Aug 10 12:13 .
> >  2 drwxr-xr-x.  3 root   root    4096 Aug  9 14:32 ..
> > 12 drw-------. 16 root   root    4096 Aug 10 12:13 .glusterfs
> > 31 -rw-r--r--.  2 revivo maccabi    0 Aug 10 12:13 nfs3file
> >
> > Why on the VFS layer i get uid/gid - 0/0
>
> As you have pointed out above, the file is created with 0:0
> owner:group but subsequent operations change owner and group using
> chown and chgrp. This is because the glusterfsd(brick daemon) process
> always runs as root. I don't know the exact reason why setfsuid and
> setfsgid are not used although the code exist.
>
> Amar/Pranith/Raghavendra/Vijay,
>
> Do you know why HAVE_SET_FSID is undefined in line
> https://github.com/gluster/glusterfs/blob/master/xlators/
> storage/posix/src/posix.c#L65
>
>
Its been ~10 years since its disabled in codebase, and I don't recollect
why completely right now.

By checking the patch [1] which got this change, I couldn't make out much:
Probably something to do with Solaris support IMO.

[1] -
https://github.com/gluster/historic/commit/3176ddf99f701412bd799cc730afd598c2a13e39

May be time to run a test by removing that line as we are friendly with
only Linux/BSD right now.

Regards,
Amar



> Thanks,
> Raghavendra Talur
>



-- 
Amar Tumballi (amarts)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gluster.org/pipermail/gluster-devel/attachments/20170817/1e681cbf/attachment.html>