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

[Murali Vilayannur]

Sam,

> Aren't we bouncing back and forth on features that we've added?
yeah; I know :) sorry about that..
what do you think we should do? :)
>
> Regarding the patch:  Does this conflict with what's in
> pvfs2_get_sb?  When we create the root inode we specify the sticky
> bit there as well.
yes it does conflict.. D'oh I cannot even generate patches properly these days
I missed the changes I had made locally to super.c..
Just remove the S_ISVTX changes like you mentioned.
thanks!
Murali

>
> -sam
>
> On Jun 28, 2007, at 1:57 PM, Murali Vilayannur wrote:
>
> > 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
> >> > >> >
> >> > >>
> >> > >>
> >> > > _______________________________________________
> >> > > Pvfs2-developers mailing list
> >> > > Pvfs2-developers at beowulf-underground.org
> >> > > http://www.beowulf-underground.org/mailman/listinfo/pvfs2-
> >> developers
> >> > >
> >> >
> >>
> >>
> >> <perm.patch>
>
>