Date: Mon, 8 Nov 2010 11:10:39 -0500
From: "J. Bruce Fields" <bfields@fieldses.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Bryan Schumaker <bjschuma@netapp.com>, linux-nfs@vger.kernel.org,
        linux-kernel@vger.kernel.org, willy@debian.org, sfr@canb.auug.org.au
Subject: Re: [PATCH 1/2] locks: let the caller free file_lock on ->setlease
 failure
Message-ID: <20101108161038.GE12760@fieldses.org>
References: <20101027133924.GB6328@fieldses.org>
 <201010271546.09036.arnd@arndb.de>
 <20101027145538.GC6328@fieldses.org>
 <20101027145929.GA5788@infradead.org>
 <20101030212500.GE480@fieldses.org>
 <20101031123419.GA4491@infradead.org>
 <20101031123510.GA4520@infradead.org>
 <20101103204147.GA6777@fieldses.org>
 <20101104014024.GA22498@fieldses.org>
 <20101106190332.GA15850@infradead.org>
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In-Reply-To: <20101106190332.GA15850@infradead.org>
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On Sat, Nov 06, 2010 at 03:03:32PM -0400, Christoph Hellwig wrote:
> On Wed, Nov 03, 2010 at 09:40:24PM -0400, J. Bruce Fields wrote:
> > The irritating thing is that the only lease user I understand is the
> > nfsd code, and it doesn't want this lease-merging behavior; the only
> > reason that fl_change is there is so it can just turn this case into an
> > error every time.
> 
> Yes.
> 
> > And I have no idea what the requirements are of any other users: do
> > leases behave like this on purpose, or was it just an arbitrary choice,
> > and does anyone depend on it now?
> 
> Adding Willy and Stephen to the Cc list as they wrote the code.
> 
> > In the end maybe it would be better just to leave leases as they are and
> > define a new lock type for nfsd.
> >
> > We'd probably have to do that eventually anyway, and it'd save me trying
> > to guess what the lease semantics are supposed to be....
> 
> I'd rather see both leases and the nfs4 delegations detangled from the
> locks.c code.

What are you thinking of?

> It's far too much of a mess already anyway.
> 
> > Subject: [PATCH 1/2] locks: fix leak on merging leases
> > 
> > We must also free the passed-in lease in the case it wasn't used because
> > an existing lease was upgrade/downgraded or already existed.
> > 
> > Note the nfsd caller doesn't care because it's fl_change callback
> > returns an error in those cases.
> 
> The patch looks good to me.  Care to feed it to Linus?

Yep, will do.

--b.