[PATCH] Subject: [PATCH] xfs: fix sgid inheritance for subdirectories inheriting default acls [V3]

[Ben Myers]

Hey Carlos,

On Wed, Jul 03, 2013 at 12:24:12PM -0300, Carlos Maiolino wrote:
> Hi, any comments on this one?

This goes with generic/313, right?

http://oss.sgi.com/archives/xfs/2013-05/msg00957.html

Thanks,
	Ben

> On Fri, Jun 21, 2013 at 02:45:53PM -0300, Carlos Maiolino wrote:
> > XFS removes sgid bits of subdirectories under a directory containing a default
> > acl.
> > 
> > When a default acl is set, it implies xfs to call xfs_setattr_nonsize() in its
> > code path. Such function is shared among mkdir and chmod system calls, and
> > does some checks unneeded by mkdir (calling inode_change_ok()). Such checks
> > remove sgid bit from the inode after it has been granted.
> > 
> > With this patch, we extend the meaning of XFS_ATTR_NOACL flag to avoid these
> > checks when acls are being inherited (thanks hch).
> > 
> > Also, xfs_setattr_mode, doesn't need to re-check for group id and capabilities
> > permissions, this only implies in another try to remove sgid bit from the
> > directories. Such check is already done either on inode_change_ok() or
> > xfs_setattr_nonsize().
> > 
> > Changelog:
> > 
> > V2: Extends the meaning of XFS_ATTR_NOACL instead of wrap the tests into another
> >     function
> > 
> > V3: Remove S_ISDIR check in xfs_setattr_nonsize() from the patch
> > 
> > Signed-off-by: Carlos Maiolino <cmaiolino at redhat.com>
> > ---
> >  fs/xfs/xfs_iops.c | 20 ++++++++++----------
> >  1 file changed, 10 insertions(+), 10 deletions(-)
> > 
> > diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
> > index ca9ecaa..2e5aca8 100644
> > --- a/fs/xfs/xfs_iops.c
> > +++ b/fs/xfs/xfs_iops.c
> > @@ -467,9 +467,6 @@ xfs_setattr_mode(
> >  	ASSERT(tp);
> >  	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
> >  
> > -	if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
> > -		mode &= ~S_ISGID;
> > -
> >  	ip->i_d.di_mode &= S_IFMT;
> >  	ip->i_d.di_mode |= mode & ~S_IFMT;
> >  
> > @@ -495,15 +492,18 @@ xfs_setattr_nonsize(
> >  
> >  	trace_xfs_setattr(ip);
> >  
> > -	if (mp->m_flags & XFS_MOUNT_RDONLY)
> > -		return XFS_ERROR(EROFS);
> > +	/* If acls are being inherited, we already have this checked */
> > +	if (!(flags & XFS_ATTR_NOACL)) {
> > +		if (mp->m_flags & XFS_MOUNT_RDONLY)
> > +			return XFS_ERROR(EROFS);
> >  
> > -	if (XFS_FORCED_SHUTDOWN(mp))
> > -		return XFS_ERROR(EIO);
> > +		if (XFS_FORCED_SHUTDOWN(mp))
> > +			return XFS_ERROR(EIO);
> >  
> > -	error = -inode_change_ok(inode, iattr);
> > -	if (error)
> > -		return XFS_ERROR(error);
> > +		error = -inode_change_ok(inode, iattr);
> > +		if (error)
> > +			return XFS_ERROR(error);
> > +	}
> >  
> >  	ASSERT((mask & ATTR_SIZE) == 0);
> >  
> > -- 
> > 1.8.1.4
> > 
> > _______________________________________________
> > xfs mailing list
> > xfs at oss.sgi.com
> > http://oss.sgi.com/mailman/listinfo/xfs
> 
> -- 
> Carlos
> 
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