From patchwork Fri Sep 3 10:29:35 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 63628 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id F1D70B71A2 for ; Fri, 3 Sep 2010 20:42:31 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757007Ab0ICKbW (ORCPT ); Fri, 3 Sep 2010 06:31:22 -0400 Received: from hera.kernel.org ([140.211.167.34]:35722 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756986Ab0ICKbT (ORCPT ); Fri, 3 Sep 2010 06:31:19 -0400 Received: from htj.dyndns.org (localhost [127.0.0.1]) by hera.kernel.org (8.14.4/8.14.3) with ESMTP id o83AUaNa011398; Fri, 3 Sep 2010 10:30:37 GMT X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.95.2 at hera.kernel.org Received: by htj.dyndns.org (Postfix, from userid 10000) id 4CCCF1CC0715; Fri, 3 Sep 2010 12:30:03 +0200 (CEST) From: Tejun Heo To: 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, dm-devel@redhat.com, hch@lst.de, konishi.ryusuke@lab.ntt.co.jp, James.Bottomley@suse.de, tytso@mit.edu, chris.mason@oracle.com, swhiteho@redhat.com, vst@vlnb.net, jack@suse.cz, rwheeler@redhat.com, hare@suse.de, neilb@suse.de, rusty@rustcorp.com.au, mst@redhat.com, snitzer@redhat.com, k-ueda@ct.jp.nec.com, mpatocka@redhat.com Cc: Tejun Heo Subject: [PATCH 20/41] lguest: replace VIRTIO_F_BARRIER support with VIRTIO_F_FLUSH support Date: Fri, 3 Sep 2010 12:29:35 +0200 Message-Id: <1283509796-1510-21-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1283509796-1510-1-git-send-email-tj@kernel.org> References: <1283509796-1510-1-git-send-email-tj@kernel.org> X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on hera.kernel.org X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Fri, 03 Sep 2010 10:30:42 +0000 (UTC) Sender: linux-ide-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org VIRTIO_F_BARRIER is deprecated. Replace it with VIRTIO_F_FLUSH support. Signed-off-by: Tejun Heo Cc: Rusty Russell Cc: Christoph Hellwig --- Documentation/lguest/lguest.c | 29 +++++++++-------------------- 1 files changed, 9 insertions(+), 20 deletions(-) diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 8a6a8c6..dc73bc5 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -1640,15 +1640,6 @@ static void blk_request(struct virtqueue *vq) off = out->sector * 512; /* - * The block device implements "barriers", where the Guest indicates - * that it wants all previous writes to occur before this write. We - * don't have a way of asking our kernel to do a barrier, so we just - * synchronize all the data in the file. Pretty poor, no? - */ - if (out->type & VIRTIO_BLK_T_BARRIER) - fdatasync(vblk->fd); - - /* * In general the virtio block driver is allowed to try SCSI commands. * It'd be nice if we supported eject, for example, but we don't. */ @@ -1680,6 +1671,13 @@ static void blk_request(struct virtqueue *vq) /* Die, bad Guest, die. */ errx(1, "Write past end %llu+%u", off, ret); } + + wlen = sizeof(*in); + *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR); + } else if (out->type & VIRTIO_BLK_T_FLUSH) { + /* Flush */ + ret = fdatasync(vblk->fd); + verbose("FLUSH fdatasync: %i\n", ret); wlen = sizeof(*in); *in = (ret >= 0 ? VIRTIO_BLK_S_OK : VIRTIO_BLK_S_IOERR); } else { @@ -1703,15 +1701,6 @@ static void blk_request(struct virtqueue *vq) } } - /* - * OK, so we noted that it was pretty poor to use an fdatasync as a - * barrier. But Christoph Hellwig points out that we need a sync - * *afterwards* as well: "Barriers specify no reordering to the front - * or the back." And Jens Axboe confirmed it, so here we are: - */ - if (out->type & VIRTIO_BLK_T_BARRIER) - fdatasync(vblk->fd); - /* Finished that request. */ add_used(vq, head, wlen); } @@ -1736,8 +1725,8 @@ static void setup_block_file(const char *filename) vblk->fd = open_or_die(filename, O_RDWR|O_LARGEFILE); vblk->len = lseek64(vblk->fd, 0, SEEK_END); - /* We support barriers. */ - add_feature(dev, VIRTIO_BLK_F_BARRIER); + /* We support FLUSH. */ + add_feature(dev, VIRTIO_BLK_F_FLUSH); /* Tell Guest how many sectors this device has. */ conf.capacity = cpu_to_le64(vblk->len / 512);