From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 26/30] ext4: do not send discards as barriers Date: Tue, 31 Aug 2010 10:11:34 +0200 Message-ID: <4C7CB936.8010509@kernel.org> References: <1282751267-3530-1-git-send-email-tj@kernel.org> <1282751267-3530-27-git-send-email-tj@kernel.org> <20100825155842.GA3229@lst.de> <20100825160032.GC3229@lst.de> <4C753D75.2010305@kernel.org> <20100825200223.GE2738@quack.suse.cz> <4C76250B.6060800@kernel.org> <20100827173147.GA12374@quack.suse.cz> <20100830202034.GB12226@quack.quadriga.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Jeff Moyer , Christoph Hellwig , jaxboe@fusionio.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, linux-raid@vger.kernel.org, James.Bottomley@suse.de, tytso@mit.edu, chris.mason@oracle.com, swhiteho@redhat.com, konishi.ryusuke@lab.ntt.co.jp, dm-devel@redhat.com, vst@vlnb.net, rwheeler@redhat.com, hare@suse.de, neilb@suse.de, rusty@rustcorp.com.au, mst@redhat.com, jeremy@goop.org, snitzer@redhat.com, k-ueda@ct.jp.nec.com, Christoph Hellwig To: Jan Kara Return-path: In-Reply-To: <20100830202034.GB12226@quack.quadriga.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On 08/30/2010 10:20 PM, Jan Kara wrote: > My setup is that I have a dedicated partition / drive for a filesystem > which is written to from a guest kernel running under KVM. I have set it up > using virtio driver with cache=writeback so that the host caches the writes > in a similar way disk caches them. At some point I just kill the qemu-kvm > process and at that point I'd like to also throw away data cached by the > host... $ echo 1 > /sys/block/sdX/device/delete $ echo - - - > /sys/class/scsi_host/hostX/scan should do the trick. Thanks. -- tejun