From: Matthew Wilcox Subject: Re: minix/ext2 + rd problem Date: Wed, 15 Oct 2008 13:22:54 -0600 Message-ID: <20081015192254.GL15064@parisc-linux.org> References: <20081015041644.GA24613@wotan.suse.de> <20081015140523.GA30641@wotan.suse.de> <20081015143425.GA2316@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Richard Kojedzinszky , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Nick Piggin Return-path: Content-Disposition: inline In-Reply-To: <20081015143425.GA2316@wotan.suse.de> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Wed, Oct 15, 2008 at 04:34:25PM +0200, Nick Piggin wrote: > You can flush and invalidate the blockdev with the --flushbufs argument > to blockdev command. However you can't use this with ramdisk devices: > someone thought it would be a good idea to save on precious ioctl space > and implemented totally different semantics on that device with the > same ioctl (it throws away the underlying data as well as the cache). What happens if we declare that a bug and fix it (and add a new ioctl to actually throw away the data ... oh, wait, we have one, it's BLKDISCARD)? -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."