[Pvfs2-developers] Re: setting xattrs on pvfs2 root

[Murali Vilayannur]

Phil,
Umm.. The problem is that we mark the root directory as sticky so that
users can create files/directories at the top level instead of having
admins create directories owned by a user under top level. The kernel
does not allow setxattr on inodes marked sticky..

if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) {
                if (!S_ISREG(inode->i_mode) &&
                    (!S_ISDIR(inode->i_mode) || inode->i_mode & S_ISVTX)) <--
                        return -EPERM;
        }
Thats why we don't even have a chance to subvirt those checks..
What do you guys suggest? Shall we step back and make the root
directory non-sticky by default? That way admins will need to
explicitly create user directories etc and chown them.
I think a rerun of ltp may also be required if we do this change.
comments?
Murali

On 6/28/07, Phil Carns <pcarns at wastedcycles.org> wrote:
> This is with 2.6 (both very recent and relatively old version).  Many
> thanks for looking at it.
>
> -Phil
>
> Murali Vilayannur wrote:
> > hi Phil,
> > Are you using 2.4. kernel versions? or 2.6?
> > If xattrs dont work, ACLs also won't work.
> > I will dig into this and let you know what I find out..
> > thanks,
> > Murali
> >
> > On 6/28/07, Phil Carns <pcarns at wastedcycles.org> wrote:
> >> I am interested in this because it would be nice to be able to set
> >> tuning options at the root directory level without modifying the server
> >> side configuration files.  I also wonder if this issue would cause
> >> problems for ACLs on the root directory.
> >>
> >> -Phil
> >>
> >> Murali Vilayannur wrote:
> >> > Hey Phil,
> >> > Sorry I forgot to get back to you on this..
> >> > No I don't think this would work.
> >> > It is a kernel module issue that I hadnt tracked down fully..
> >> > Do you need this feature?
> >> > thanks,
> >> > Murali
> >> >
> >> > On 6/27/07, Phil Carns <pcarns at wastedcycles.org> wrote:
> >> >> Just pinging on this one again- has any one else bumped into this
> >> >> problem?
> >> >>
> >> >> -Phil
> >> >>
> >> >> Phil Carns wrote:
> >> >> > It looks like pvfs2 does not allow you to set xattrs on the root
> >> >> > directory.  Is this expected?
> >> >> >
> >> >> > # checking the mount options:
> >> >> >
> >> >> >  > mount -t pvfs2
> >> >> > tcp://localhost:3334/pvfs2-fs on /mnt/pvfs2 type pvfs2
> >> (rw,user_xattr)
> >> >> >
> >> >> > # confirming that xattrs can be set on a normal directory:
> >> >> >
> >> >> >  > setfattr -n user.pvfs2.num_dfiles -v "1" /mnt/pvfs2/dir1
> >> >> >  > getfattr -n user.pvfs2.num_dfiles /mnt/pvfs2/dir1
> >> >> > getfattr: Removing leading '/' from absolute path names
> >> >> > # file: mnt/pvfs2/dir1
> >> >> > user.pvfs2.num_dfiles="1"
> >> >> >
> >> >> > # trying to set xattrs on the root directory:
> >> >> >
> >> >> >  > setfattr -n user.pvfs2.num_dfiles -v "1" /mnt/pvfs2
> >> >> > setfattr: /mnt/pvfs2: Operation not permitted
> >> >> >  > getfattr -n user.pvfs2.num_dfiles /mnt/pvfs2
> >> >> > /mnt/pvfs2: user.pvfs2.num_dfiles: No such attribute
> >> >> >
> >> >> > All of the above is run as root.  I don't think it is anything
> >> special
> >> >> > about the num_dfiles attribute either; it looks like I can't set any
> >> >> > xattrs on the root directory.  It always responds with "Operation
> >> not
> >> >> > permitted".
> >> >> >
> >> >> > -Phil
> >> >> >
> >> >>
> >> >> _______________________________________________
> >> >> Pvfs2-developers mailing list
> >> >> Pvfs2-developers at beowulf-underground.org
> >> >> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers
> >> >>
> >>
> >>
>
>