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

[Murali Vilayannur]

oops.. wrong file..
Resending patch..
Murali

On 6/28/07, Murali Vilayannur <murali.vilayannur at gmail.com> wrote:
> Hey rob,
> I agree; I forget the history behind why we added all this in the first place :)
> Do you guys recollect?
> Anyways, attached patch should fix this cleanly..
> We have to doc on the FAQ that top-level directories are for
> root-users only henceforth.
> We should also recommend that people do a chown 755 on the root
> directory as well in case they don't wish to reformat.
> Phil, you should be able to do setfattr and getfattr on root directory
> with or without the mount time acl option with this patch.
> thanks,
> Murali
>
> On 6/28/07, Rob Ross <rross at mcs.anl.gov> wrote:
> > seems like this is something that admins have had to deal with forever;
> > we're not asking anyone to do anything unusual... -- rob
> >
> > Murali Vilayannur wrote:
> > > Hi Sam,
> > > You mean remove it for good from the code, right?
> > > A chmod -t does not do the trick. We explicitly reset it internally
> > > sadly :(
> > > I will send out a patch to do this trick *if* folks are willing to
> > > live with no top-level
> > > files or dirs...
> > > Murali
> > >
> > > On 6/28/07, Sam Lang <slang at mcs.anl.gov> wrote:
> > >>
> > >> Hi Murali,
> > >>
> > >> Can't we just have people remove the sticky bit so they can set xattrs?
> > >>
> > >> -sam
> > >>
> > >> On Jun 28, 2007, at 12:37 PM, Murali Vilayannur wrote:
> > >>
> > >> > 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
> > >> >> >> >>
> > >> >> >>
> > >> >> >>
> > >> >>
> > >> >>
> > >> > _______________________________________________
> > >> > Pvfs2-developers mailing list
> > >> > Pvfs2-developers at beowulf-underground.org
> > >> > http://www.beowulf-underground.org/mailman/listinfo/pvfs2-developers
> > >> >
> > >>
> > >>
> > > _______________________________________________
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> > >
> >
>
>
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