From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pavel Emelyanov <xemul@parallels.com>
Subject: Re: [PATCH 6/10] fuse: Trust kernel i_size only
Date: Thu, 05 Jul 2012 18:10:56 +0400
Message-ID: <4FF5A070.7030206@parallels.com>
References: <4FF3156E.8030109@parallels.com> <4FF3160B.6090501@parallels.com> <8762a3pp3m.fsf@tucsk.pomaz.szeredi.hu>
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Cc: "fuse-devel@lists.sourceforge.net" <fuse-devel@lists.sourceforge.net>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	James Bottomley <jbottomley@parallels.com>,
	Kirill Korotaev <dev@parallels.com>
To: Miklos Szeredi <miklos@szeredi.hu>
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On 07/04/2012 06:39 PM, Miklos Szeredi wrote:
> Pavel Emelyanov <xemul@parallels.com> writes:
> 
>> Make fuse think that when writeback is on the inode's i_size is alway
>> up-to-date and not update it with the value received from the
>> userspace. This is done because the page cache code may update i_size
>> without letting the FS know.
> 
> Similar rule applies to i_mtime.  Except it's even more tricky, since
> you have to flush the mtime together with the data (the flush should not
> update the modification time).  And we have other operations which also
> change the mtime, and those also need to be updated.

Yup, I've missed that part :( Thanks for pointing this out.

> We should probably look at what NFS is doing.

I'll look at what can be done about it.


Thanks,
Pavel