From patchwork Mon Nov 19 20:39:45 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Priebe - Profihost AG X-Patchwork-Id: 200155 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 0C0302C0097 for ; Tue, 20 Nov 2012 08:06:52 +1100 (EST) Received: from localhost ([::1]:56181 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TaYYL-00087w-S7 for incoming@patchwork.ozlabs.org; Mon, 19 Nov 2012 16:06:49 -0500 Received: from eggs.gnu.org ([208.118.235.92]:56597) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TaYYA-00087g-Pc for qemu-devel@nongnu.org; Mon, 19 Nov 2012 16:06:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TaYY9-00020W-53 for qemu-devel@nongnu.org; Mon, 19 Nov 2012 16:06:38 -0500 Received: from packetbuilder64bit.de-nserver.de ([85.158.179.228]:45008) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TaYY8-000201-Pa for qemu-devel@nongnu.org; Mon, 19 Nov 2012 16:06:37 -0500 Received: (qmail 31891 invoked by uid 0); 19 Nov 2012 21:39:54 +0100 From: Stefan Priebe To: qemu-devel@nongnu.org Date: Mon, 19 Nov 2012 21:39:45 +0100 Message-Id: <1353357585-31746-2-git-send-email-s.priebe@profihost.ag> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1353357585-31746-1-git-send-email-s.priebe@profihost.ag> References: <1353357585-31746-1-git-send-email-s.priebe@profihost.ag> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] X-Received-From: 85.158.179.228 Cc: Stefan Priebe , Stefan Priebe Subject: [Qemu-devel] [PATCH] rbd block driver 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 qemu also had in iscsi block driver between cancellation and io completition. qemu_rbd_aio_cancel was not synchronously waiting for the end of the command. It also removes the useless cancelled flag and introduces instead a status flag with EINPROGRESS like iscsi block driver. Signed-off-by: Stefan Priebe --- block/rbd.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/block/rbd.c b/block/rbd.c index 5a0f79f..7b3bcbb 100644 --- a/block/rbd.c +++ b/block/rbd.c @@ -76,7 +76,7 @@ typedef struct RBDAIOCB { int64_t sector_num; int error; struct BDRVRBDState *s; - int cancelled; + int status; } RBDAIOCB; typedef struct RADOSCB { @@ -376,9 +376,7 @@ 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); + if (acb->bh) { goto done; } @@ -406,9 +404,12 @@ static void qemu_rbd_complete_aio(RADOSCB *rcb) acb->ret = r; } } + acb->status = acb->ret; + /* 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); } @@ -573,7 +574,10 @@ static void qemu_rbd_close(BlockDriverState *bs) static void qemu_rbd_aio_cancel(BlockDriverAIOCB *blockacb) { RBDAIOCB *acb = (RBDAIOCB *) blockacb; - acb->cancelled = 1; + + while (acb->status == -EINPROGRESS) { + qemu_aio_wait(); + } } static AIOPool rbd_aio_pool = { @@ -642,10 +646,11 @@ static void rbd_aio_bh_cb(void *opaque) qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); } qemu_vfree(acb->bounce); - acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret)); qemu_bh_delete(acb->bh); acb->bh = NULL; + acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret)); + qemu_aio_release(acb); } @@ -689,8 +694,8 @@ static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs, acb->ret = 0; acb->error = 0; 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);