From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:32775) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RPzkW-0004Po-VK for qemu-devel@nongnu.org; Mon, 14 Nov 2011 11:51:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RPzkU-0000vQ-FD for qemu-devel@nongnu.org; Mon, 14 Nov 2011 11:51:12 -0500 Received: from mail-gx0-f173.google.com ([209.85.161.173]:61768) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RPzkU-0000vM-Cm for qemu-devel@nongnu.org; Mon, 14 Nov 2011 11:51:10 -0500 Received: by ggnr4 with SMTP id r4so347544ggn.4 for ; Mon, 14 Nov 2011 08:51:09 -0800 (PST) Sender: Paolo Bonzini From: Paolo Bonzini Date: Mon, 14 Nov 2011 17:50:50 +0100 Message-Id: <1321289454-9219-3-git-send-email-pbonzini@redhat.com> In-Reply-To: <1321289454-9219-1-git-send-email-pbonzini@redhat.com> References: <1321289454-9219-1-git-send-email-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 1.1 2/6] block: simplify failure handling for bdrv_aio_multiwrite List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Now that early failure of bdrv_aio_writev is not possible anymore, mcb->num_requests can be set before the loop starts. Signed-off-by: Paolo Bonzini --- block.c | 28 ++-------------------------- 1 files changed, 2 insertions(+), 26 deletions(-) diff --git a/block.c b/block.c index 2b72d2c..05b0e2c 100644 --- a/block.c +++ b/block.c @@ -2419,37 +2419,13 @@ int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); - /* - * Run the aio requests. As soon as one request can't be submitted - * successfully, fail all requests that are not yet submitted (we must - * return failure for all requests anyway) - * - * num_requests cannot be set to the right value immediately: If - * bdrv_aio_writev fails for some request, num_requests would be too high - * and therefore multiwrite_cb() would never recognize the multiwrite - * request as completed. We also cannot use the loop variable i to set it - * when the first request fails because the callback may already have been - * called for previously submitted requests. Thus, num_requests must be - * incremented for each request that is submitted. - * - * The problem that callbacks may be called early also means that we need - * to take care that num_requests doesn't become 0 before all requests are - * submitted - multiwrite_cb() would consider the multiwrite request - * completed. A dummy request that is "completed" by a manual call to - * multiwrite_cb() takes care of this. - */ - mcb->num_requests = 1; - - // Run the aio requests + /* Run the aio requests. */ + mcb->num_requests = num_reqs; for (i = 0; i < num_reqs; i++) { - mcb->num_requests++; bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov, reqs[i].nb_sectors, multiwrite_cb, mcb); } - /* Complete the dummy request */ - multiwrite_cb(mcb, 0); - return 0; } -- 1.7.7.1