From patchwork Thu Dec 13 15:10:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 206135 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 495CA2C00A6 for ; Fri, 14 Dec 2012 02:49:13 +1100 (EST) Received: from localhost ([::1]:34474 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TjB27-0001yH-Hl for incoming@patchwork.ozlabs.org; Thu, 13 Dec 2012 10:49:11 -0500 Received: from eggs.gnu.org ([208.118.235.92]:37252) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TjARy-0000oP-Ud for qemu-devel@nongnu.org; Thu, 13 Dec 2012 10:12:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TjARQ-0005zB-TG for qemu-devel@nongnu.org; Thu, 13 Dec 2012 10:11:50 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2972) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TjARQ-0005yw-Jy for qemu-devel@nongnu.org; Thu, 13 Dec 2012 10:11:16 -0500 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id qBDFBFo7004872 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 13 Dec 2012 10:11:15 -0500 Received: from dhcp-5-188.str.redhat.com (dhcp-200-232.str.redhat.com [10.33.200.232]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id qBDFApma026810; Thu, 13 Dec 2012 10:11:14 -0500 From: Kevin Wolf To: anthony@codemonkey.ws Date: Thu, 13 Dec 2012 16:10:28 +0100 Message-Id: <1355411450-12761-22-git-send-email-kwolf@redhat.com> In-Reply-To: <1355411450-12761-1-git-send-email-kwolf@redhat.com> References: <1355411450-12761-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH 21/43] rbd: Fix race between aio completition and aio cancel X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Stefan Priebe This one fixes a race which qemu had also in iscsi block driver between cancellation and io completition. qemu_rbd_aio_cancel was not synchronously waiting for the end of the command. To archieve this it introduces a new status flag which uses -EINPROGRESS. Signed-off-by: Stefan Priebe Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/rbd.c | 20 ++++++++++++-------- 1 files changed, 12 insertions(+), 8 deletions(-) diff --git a/block/rbd.c b/block/rbd.c index f3becc7..737bab1 100644 --- a/block/rbd.c +++ b/block/rbd.c @@ -77,6 +77,7 @@ typedef struct RBDAIOCB { int error; struct BDRVRBDState *s; int cancelled; + int status; } RBDAIOCB; typedef struct RADOSCB { @@ -376,12 +377,6 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb) RBDAIOCB *acb = rcb->acb; int64_t r; - if (acb->cancelled) { - qemu_vfree(acb->bounce); - qemu_aio_release(acb); - goto done; - } - r = rcb->ret; if (acb->cmd == RBD_AIO_WRITE || @@ -409,7 +404,6 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb) /* Note that acb->bh can be NULL in case where the aio was cancelled */ acb->bh = qemu_bh_new(rbd_aio_bh_cb, acb); qemu_bh_schedule(acb->bh); -done: g_free(rcb); } @@ -568,6 +562,12 @@ static void qemu_rbd_aio_cancel(BlockDriverAIOCB *blockacb) { RBDAIOCB *acb = (RBDAIOCB *) blockacb; acb->cancelled = 1; + + while (acb->status == -EINPROGRESS) { + qemu_aio_wait(); + } + + qemu_aio_release(acb); } static const AIOCBInfo rbd_aiocb_info = { @@ -639,8 +639,11 @@ static void rbd_aio_bh_cb(void *opaque) acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret)); qemu_bh_delete(acb->bh); acb->bh = NULL; + acb->status = 0; - qemu_aio_release(acb); + if (!acb->cancelled) { + qemu_aio_release(acb); + } } static int rbd_aio_discard_wrapper(rbd_image_t image, @@ -685,6 +688,7 @@ static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs, acb->s = s; acb->cancelled = 0; acb->bh = NULL; + acb->status = -EINPROGRESS; if (cmd == RBD_AIO_WRITE) { qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size);