From patchwork Mon Apr 1 14:08:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 1072856 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=209.51.188.17; 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 [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 44Xvh32Pltz9sPB for ; Tue, 2 Apr 2019 01:22:59 +1100 (AEDT) Received: from localhost ([127.0.0.1]:36629 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hAxpx-0007s8-9j for incoming@patchwork.ozlabs.org; Mon, 01 Apr 2019 10:22:57 -0400 Received: from eggs.gnu.org ([209.51.188.92]:45851) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hAxcj-0001zG-12 for qemu-devel@nongnu.org; Mon, 01 Apr 2019 10:09:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hAxci-0004mD-1J for qemu-devel@nongnu.org; Mon, 01 Apr 2019 10:09:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:18738) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hAxcf-0004jl-DH; Mon, 01 Apr 2019 10:09:13 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B1AC23688E; Mon, 1 Apr 2019 14:09:12 +0000 (UTC) Received: from blue.redhat.com (ovpn-116-75.phx2.redhat.com [10.3.116.75]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5987119C70; Mon, 1 Apr 2019 14:09:09 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Date: Mon, 1 Apr 2019 09:08:54 -0500 Message-Id: <20190401140903.19186-6-eblake@redhat.com> In-Reply-To: <20190401140903.19186-1-eblake@redhat.com> References: <20190401140903.19186-1-eblake@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 01 Apr 2019 14:09:12 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 05/14] qemu-img: Gracefully shutdown when map can't finish 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: Kevin Wolf , John Snow , "open list:Block layer core" , Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Trying 'qemu-img map -f raw nbd://localhost:10809' causes the NBD server to output a scary message: qemu-nbd: Disconnect client, due to: Failed to read request: Unexpected end-of-file before all bytes were read This is because the NBD client, being remote, has no way to expose a human-readable map (the --output=json data is fine, however). But because we exit(1) right after the message, causing the client to bypass all block cleanup, the server sees the abrupt exit and warns, whereas it would be silent had the client had a chance to send NBD_CMD_DISC. Other protocols may have similar cleanup issues, where failure to blk_unref() could cause unintended effects. Signed-off-by: Eric Blake Message-Id: <20190326184043.7544-1-eblake@redhat.com> Reviewed-by: John Snow Reviewed-by: Kevin Wolf --- qemu-img.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index 03a9a10dec1..76a961df824 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -2736,14 +2736,14 @@ static int img_info(int argc, char **argv) return 0; } -static void dump_map_entry(OutputFormat output_format, MapEntry *e, - MapEntry *next) +static int dump_map_entry(OutputFormat output_format, MapEntry *e, + MapEntry *next) { switch (output_format) { case OFORMAT_HUMAN: if (e->data && !e->has_offset) { error_report("File contains external, encrypted or compressed clusters."); - exit(1); + return -1; } if (e->data && !e->zero) { printf("%#-16"PRIx64"%#-16"PRIx64"%#-16"PRIx64"%s\n", @@ -2776,6 +2776,7 @@ static void dump_map_entry(OutputFormat output_format, MapEntry *e, } break; } + return 0; } static int get_block_status(BlockDriverState *bs, int64_t offset, @@ -2968,12 +2969,15 @@ static int img_map(int argc, char **argv) } if (curr.length > 0) { - dump_map_entry(output_format, &curr, &next); + ret = dump_map_entry(output_format, &curr, &next); + if (ret < 0) { + goto out; + } } curr = next; } - dump_map_entry(output_format, &curr, NULL); + ret = dump_map_entry(output_format, &curr, NULL); out: blk_unref(blk);