Re: [PATCH] autofs4 doesn't expire

[Maneesh Soni <maneesh@in.ibm.com>]

On Tue, Aug 05, 2003 at 10:08:48PM -0700, Andrew Morton wrote:
> Maneesh Soni <maneesh@in.ibm.com> wrote:
> >
> >  +	if (vfs) {
> >  +		if (is_vfsmnt_tree_busy(vfs))
> >  +			ret--;
> >  +		/* just to reduce ref count taken in lookup_mnt
> >  +	 	 * cannot call mntput() here
> >  +	 	 */
> >  +		atomic_dec(&vfs->mnt_count);
> >  +	}
> 
> Doesn't work, does it?  If someone else does a mntput() just beforehand,
> __mntput() never gets run.
> 

no.. it will not work. looks like we have to unlock and lock dcache_lock and
use mntput as I did earlier. But I think, it will be really nice if Jermey
can revisit is_tree_busy() code.

There can be other problems like the checking d_count for dentries under
dcache_lock(). As users can do dget() or dput() manipulating d_count without
dcache_lock(). 

Maneesh

-- 
Maneesh Soni
IBM Linux Technology Center, 
IBM India Software Lab, Bangalore.
Phone: +91-80-5044999 email: maneesh@in.ibm.com
http://lse.sourceforge.net/