From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe Subject: [PATCH] rbd block driver fix race between aio completition and aio cancel Date: Mon, 19 Nov 2012 21:43:07 +0100 Message-ID: <50AA99DB.6040307@profihost.ag> References: <1353357585-31746-1-git-send-email-s.priebe@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.profihost.ag ([85.158.179.208]:56396 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751252Ab2KSUnJ (ORCPT ); Mon, 19 Nov 2012 15:43:09 -0500 In-Reply-To: <1353357585-31746-1-git-send-email-s.priebe@profihost.ag> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "ceph-devel@vger.kernel.org" Cc: Paolo Bonzini , "pve-devel@pve.proxmox.com" 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); -- 1.7.10.4