From patchwork Tue Mar 13 17:13:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 885338 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4012Zc1MtDz9sT2 for ; Wed, 14 Mar 2018 04:55:34 +1100 (AEDT) Received: from localhost ([::1]:41657 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evo95-0001DH-Ru for incoming@patchwork.ozlabs.org; Tue, 13 Mar 2018 13:55:31 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47110) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evnUp-0007He-4o for qemu-devel@nongnu.org; Tue, 13 Mar 2018 13:13:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1evnUn-0000pr-Nf for qemu-devel@nongnu.org; Tue, 13 Mar 2018 13:13:55 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:39232 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1evnUj-0000kW-Rg; Tue, 13 Mar 2018 13:13:49 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7679240201A3; Tue, 13 Mar 2018 17:13:49 +0000 (UTC) Received: from red.redhat.com (ovpn-121-135.rdu2.redhat.com [10.10.121.135]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0F1072026DFD; Tue, 13 Mar 2018 17:13:48 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Date: Tue, 13 Mar 2018 12:13:31 -0500 Message-Id: <20180313171345.659672-4-eblake@redhat.com> In-Reply-To: <20180313171345.659672-1-eblake@redhat.com> References: <20180313171345.659672-1-eblake@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Tue, 13 Mar 2018 17:13:49 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Tue, 13 Mar 2018 17:13:49 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'eblake@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PULL 03/17] nbd/server: fix sparse read X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Vladimir Sementsov-Ogievskiy , "open list:Network Block Dev..." Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Vladimir Sementsov-Ogievskiy In case of io error in nbd_co_send_sparse_read we should not "goto reply:", as it was a fatal error and the common behavior is to disconnect in this case. We should not try to send the client an additional error reply, since we already hit a channel-io error on our previous attempt to send one. Fix this by handling block-status error in nbd_co_send_sparse_read, so nbd_co_send_sparse_read fails only on io error. Then just skip common "reply:" code path in nbd_trip. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20180308184636.178534-3-vsementsov@virtuozzo.com> [eblake: grammar tweaks] Signed-off-by: Eric Blake --- nbd/server.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index 3d0f024193c..5f292064af0 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1366,6 +1366,10 @@ static int coroutine_fn nbd_co_send_structured_error(NBDClient *client, return nbd_co_send_iov(client, iov, 1 + !!iov[1].iov_len, errp); } +/* Do a sparse read and send the structured reply to the client. + * Returns -errno if sending fails. bdrv_block_status_above() failure is + * reported to the client, at which point this function succeeds. + */ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, uint64_t handle, uint64_t offset, @@ -1386,8 +1390,13 @@ static int coroutine_fn nbd_co_send_sparse_read(NBDClient *client, bool final; if (status < 0) { - error_setg_errno(errp, -status, "unable to check for holes"); - return status; + char *msg = g_strdup_printf("unable to check for holes: %s", + strerror(-status)); + + ret = nbd_co_send_structured_error(client, handle, -status, msg, + errp); + g_free(msg); + return ret; } assert(pnum && pnum <= size - progress); final = progress + pnum == size; @@ -1568,7 +1577,7 @@ static coroutine_fn void nbd_trip(void *opaque) request.from, req->data, request.len, &local_err); if (ret < 0) { - goto reply; + goto replied; } goto done; } @@ -1665,6 +1674,8 @@ reply: req->data, reply_data_len, &local_err); } g_free(msg); + +replied: if (ret < 0) { error_prepend(&local_err, "Failed to send reply: "); goto disconnect;