svn commit: r226967 - head/sys/ufs/ufs

[Peter Holm]

On Mon, Oct 31, 2011 at 12:41:41PM -0400, John Baldwin wrote:
> On Monday, October 31, 2011 11:01:47 am Peter Holm wrote:
> > Author: pho
> > Date: Mon Oct 31 15:01:47 2011
> > New Revision: 226967
> > URL: http://svn.freebsd.org/changeset/base/226967
> > 
> > Log:
> >   The kern_renameat() looks up the fvp using the DELETE flag, which causes
> >   the removal of the name cache entry for fvp.
> >   
> >   Reported by:	Anton Yuzhaninov <citrin citrin ru>
> >   In collaboration with:	kib
> >   MFC after:	1 week
> 
> Hmm, the log message doesn't seem to quite match the change?  Was it 
> truncated?
> 

No, it was a misunderstanding on my part.

The log message should have read:
"Added missing cache purge of from argument."

- Peter

> > Modified:
> >   head/sys/ufs/ufs/ufs_vnops.c
> > 
> > Modified: head/sys/ufs/ufs/ufs_vnops.c
> > 
> ==============================================================================
> > --- head/sys/ufs/ufs/ufs_vnops.c	Mon Oct 31 10:53:27 2011	(r226966)
> > +++ head/sys/ufs/ufs/ufs_vnops.c	Mon Oct 31 15:01:47 2011	(r226967)
> > @@ -1519,6 +1519,13 @@ relock:
> >  		cache_purge(fdvp);
> >  	}
> >  	error = ufs_dirremove(fdvp, fip, fcnp->cn_flags, 0);
> > +	/*
> > +	 * As the relookup of the fvp is done in two steps:
> > +	 * ufs_lookup_ino() and then VFS_VGET(), another thread might do a
> > +	 * normal lookup of the from name just before the VFS_VGET() call,
> > +	 * causing the cache entry to be re-instantiated.
> > +	 */
> > +	cache_purge(fvp);
> >  
> >  unlockout:
> >  	vput(fdvp);
> > 
> 
> -- 
> John Baldwin