Re: linux-next: manual merge of the pidfd tree with the xfs tree

[Darrick J. Wong]

On Wed, Jan 27, 2021 at 11:24:41AM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> On Mon, 25 Jan 2021 17:14:14 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> >
> > Today's linux-next merge of the pidfd tree got a conflict in:
> > 
> >   fs/xfs/xfs_inode.c
> > 
> > between commit:
> > 
> >   01ea173e103e ("xfs: fix up non-directory creation in SGID directories")
> > 
> > from the xfs tree and commit:
> > 
> >   f736d93d76d3 ("xfs: support idmapped mounts")
> > 
> > from the pidfd tree.
> > 
> > I fixed it up (see below) and can carry the fix as necessary. This
> > is now fixed as far as linux-next is concerned, but any non trivial
> > conflicts should be mentioned to your upstream maintainer when your tree
> > is submitted for merging.  You may also want to consider cooperating
> > with the maintainer of the conflicting tree to minimise any particularly
> > complex conflicts.
> > 
> > diff --cc fs/xfs/xfs_inode.c
> > index e2a1db4cee43,95b7f2ba4e06..000000000000
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@@ -809,13 -810,13 +810,13 @@@ xfs_init_new_inode
> >   	inode->i_rdev = rdev;
> >   	ip->i_d.di_projid = prid;
> >   
> >  -	if (pip && XFS_INHERIT_GID(pip)) {
> >  -		inode->i_gid = VFS_I(pip)->i_gid;
> >  -		if ((VFS_I(pip)->i_mode & S_ISGID) && S_ISDIR(mode))
> >  -			inode->i_mode |= S_ISGID;
> >  +	if (dir && !(dir->i_mode & S_ISGID) &&
> >  +	    (mp->m_flags & XFS_MOUNT_GRPID)) {
> >  +		inode->i_uid = current_fsuid();
> 
> Looking a bit harder, I replaced the above line with
> 		inode->i_uid = fsuid_into_mnt(mnt_userns);

I think that looks good, though Mr. Brauner is probably better equipped
to tell if that change is correct.

(He says watching kernel.org mail take nearly a day to come through...)

--D

> 
> >  +		inode->i_gid = dir->i_gid;
> >  +		inode->i_mode = mode;
> >   	} else {
> > - 		inode_init_owner(inode, dir, mode);
> >  -		inode->i_gid = fsgid_into_mnt(mnt_userns);
> > ++		inode_init_owner(mnt_userns, inode, dir, mode);
> >   	}
> >   
> >   	/*
> 
> -- 
> Cheers,
> Stephen Rothwell