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From: Christoph Hellwig <hch@infradead.org>
To: Michal Novotny <minovotn@redhat.com>
Cc: Ric Wheeler <rwheeler@redhat.com>,
	linux-ext4@vger.kernel.org, Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH] extend e2fsprogs functionality to add EXT2_FLAG_DIRECT option
Date: Tue, 12 Jan 2010 07:23:19 -0500	[thread overview]
Message-ID: <20100112122319.GA20596@infradead.org> (raw)
In-Reply-To: <4B4C67F5.1020009@redhat.com>

On Tue, Jan 12, 2010 at 01:15:49PM +0100, Michal Novotny wrote:
> I don't really know if I see your point but the thing here is that there  
> was no way to open a file directly (ie. using O_DIRECT). The direct  
> write support has been added only to make it possible to use both read  
> and write directly. The main reason to create this patch was to add  
> direct read support and flush capability won't help me at all. I am  
> working in Red Hat, Virtualization team on Xen so I am really not that  
> much familiar with file systems but what I needed was an option to read  
> the data directly (using O_DIRECT) in e2fsprogs. One bug was about  
> pygrub (Python version of GRUB of Xen PV guests that is internally using  
> e2fsprogs functionality to access data on ext2/3/4 partition to boot the  
> PV guests) uses outdated/cached data so some modifications were  
> necessary to open everything directly...

So to get things staigt:  you're using e2fsprogs to manipulate a life
filesystem and thing using O_DIRECT saves your ass?  I think you need to
rething your model of operation fundamentally in that case. 


  reply	other threads:[~2010-01-12 12:23 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-08  9:36 [PATCH] extend e2fsprogs functionality to add EXT2_FLAG_DIRECT option Michal Novotny
2010-01-11 20:06 ` Ric Wheeler
2010-01-12 10:54   ` Michal Novotny
2010-01-12 11:59     ` Ric Wheeler
2010-01-12 12:15       ` Michal Novotny
2010-01-12 12:23         ` Christoph Hellwig [this message]
2010-01-12 12:30           ` Michal Novotny
2010-01-12 12:46             ` Christoph Hellwig
2010-01-12 13:01               ` Michal Novotny
2010-01-12 13:04                 ` Ric Wheeler
2010-01-12 13:12                   ` Michal Novotny
2010-01-12 13:23                     ` Michal Novotny
2010-01-12 13:29                       ` Ric Wheeler
2010-01-12 13:33                         ` Michal Novotny
2010-01-12 14:33                           ` Chris Lee
2010-01-12 14:37                             ` Michal Novotny
2010-01-12 16:38                 ` Christoph Hellwig
2010-01-12 16:43                   ` Michal Novotny
2010-01-12 16:47                     ` Christoph Hellwig
2010-01-12 16:51                       ` Michal Novotny
2010-01-12 16:50                     ` Ric Wheeler
2010-01-12 16:53                       ` Michal Novotny
2010-01-12 16:56                         ` Eric Sandeen
2010-01-12 16:59                           ` Ric Wheeler
2010-01-12 17:00                             ` Michal Novotny
2010-01-14 13:46                               ` Michal Novotny
2010-01-12 12:47             ` Andreas Dilger
2010-01-12 13:04               ` Michal Novotny
2010-01-12 15:16           ` Eric Sandeen
2010-01-12 15:46             ` Michal Novotny
2010-01-12 20:01               ` Ric Wheeler

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