From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton 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 11:48:21 -0800 Message-ID: <20120131114821.c73c4150.akpm@linux-foundation.org> References: <4F213E1A.4060808@redhat.com> <1327584802-14298-1-git-send-email-ndevos@redhat.com> <20120126134051.6add3cd2.akpm@linux-foundation.org> <20120126214534.GA9319@infradead.org> <4F28102C.1070207@redhat.com> <20120131105824.c48351b6.akpm@linux-foundation.org> <20120131190425.GA10533@infradead.org> <20120131113250.816ee772.akpm@linux-foundation.org> <20120131193748.GA10093@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Niels de Vos , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Al Viro , Mikulas Patocka , Jeff Moyer , "Bryn M. Reeves" To: Christoph Hellwig Return-path: In-Reply-To: <20120131193748.GA10093@infradead.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tue, 31 Jan 2012 14:37:48 -0500 Christoph Hellwig wrote: > On Tue, Jan 31, 2012 at 11:32:50AM -0800, Andrew Morton wrote: > > I didn't say the kernel would support this as-is. > > > > If the partitioning scheme requires writing to the individual > > partitions then something would need to be done, such as a simple > > offsetting DM driver. > > Writing partition tables requires writing to them main block device. This can be done via an offsetting driver. > Seriously - if people want to support block devices nodes > 16TB dealing > with this isn't the problem. They'll need to find a way to do buffered > I/O without using the pagecache to get it right, why? I don't see the problem - supporting /dev/sdaX should be straightforward. /dev/sda rarely gets used and would need a bit of special-case handling. Please provide all the details as you see them and stop making me email more questions to you. > at which point > blkdev_get_block in either form will simply go away.