From: Trond Myklebust <Trond.Myklebust@netapp.com>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: linux-kernel@vger.kernel.org, zach.brown@oracle.com
Subject: Re: [PATCH 1/3] direct-io: make O_DIRECT IO path be page based
Date: Thu, 20 Aug 2009 09:08:13 -0400 [thread overview]
Message-ID: <1250773693.5352.24.camel@heimdal.trondhjem.org> (raw)
In-Reply-To: <20090817121137.GW12579@kernel.dk>
On Mon, 2009-08-17 at 14:11 +0200, Jens Axboe wrote:
> On Mon, Aug 17 2009, Jens Axboe wrote:
> > Switch the aops->direct_IO() and below code to use page arrays
> > instead, so that it doesn't make any assumptions about who the pages
> > belong to. This works directly for all users but NFS, which just
> > uses the same helper that the generic mapping read/write functions
> > also call.
>
> A quick NFS test reveals a simple problem - it wants to free the
> pagevec on IO completion, but for O_DIRECT it should not do that anymore
> since it'll simply inherit the given page map.
>
> There's a flag structure in the nfs_{read,write}_data structure, but I
> was not able to find out which flags (if any?!) it actually uses. So I
> just stuck an int in there. Trond?
Why not just have O_DIRECT reset the pagevec before freeing the
structure?
Cheers
Trond
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@netapp.com
www.netapp.com
next prev parent reply other threads:[~2009-08-20 13:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-17 10:34 [PATCH 0/3] Page based O_DIRECT and O_DIRECT loop Jens Axboe
2009-08-17 10:34 ` [PATCH 1/3] direct-io: make O_DIRECT IO path be page based Jens Axboe
2009-08-17 10:34 ` [PATCH 2/3] direct-io: add a "IO for kernel" flag to kiocb Jens Axboe
2009-08-17 10:34 ` [PATCH 3/3] loop: support O_DIRECT transfer mode Jens Axboe
2009-08-17 12:11 ` [PATCH 1/3] direct-io: make O_DIRECT IO path be page based Jens Axboe
2009-08-20 13:08 ` Trond Myklebust [this message]
2009-08-17 22:00 ` [PATCH 0/3] Page based O_DIRECT and O_DIRECT loop Christoph Hellwig
2009-08-18 6:40 ` Jens Axboe
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