From mboxrd@z Thu Jan  1 00:00:00 1970
From: Niels de Vos <ndevos@redhat.com>
Subject: Re: [PATCH v3] fs: Invalidate the cache for a parent block-device
 if fsync() is called for a partition
Date: Tue, 31 Jan 2012 16:00:44 +0000
Message-ID: <4F28102C.1070207@redhat.com>
References: <4F213E1A.4060808@redhat.com> <1327584802-14298-1-git-send-email-ndevos@redhat.com> <20120126134051.6add3cd2.akpm@linux-foundation.org> <20120126214534.GA9319@infradead.org>
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Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Al Viro <viro@zeniv.linux.org.uk>,
	Mikulas Patocka <mpatocka@redhat.com>,
	Jeff Moyer <jmoyer@redhat.com>,
	"Bryn M. Reeves" <bmr@redhat.com>
To: Christoph Hellwig <hch@infradead.org>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20120126214534.GA9319@infradead.org>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: linux-fsdevel.vger.kernel.org

On 01/26/2012 09:45 PM, Christoph Hellwig wrote:
> On Thu, Jan 26, 2012 at 01:40:51PM -0800, Andrew Morton wrote:
>> The Right Thing To Do here is to make the kernel behave logically and
>> predictably, then modify the userspace tools.  But if we're modifying
>> the userspace tools then we would just change userspace to issue a
>> BLKFLSBUF to /dev/sda and leave the kernel alone.
> 
> The right fix is to make partition and whole disk access coherent,
> which is fairly simply:
> 
>  - create the block device inode/mapping per gendisk, and only reference
>    count it per block_device
>  - make sure blkdev_get_block(s) applies the correct offset if used on
>    partitions
> 

This surely looks like a better way to fix this issue. I am not sure yet
how much work that would involve and if I am the right person to fix
this. If nobody beats me to it, I might send a patch for review some
(undefined) time later.

Thanks for the suggestions,
Niels