From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75A5DC63797 for ; Thu, 22 Jul 2021 18:19:39 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C1149600D0 for ; Thu, 22 Jul 2021 18:19:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C1149600D0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:37610 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m6dIH-0001KT-St for qemu-devel@archiver.kernel.org; Thu, 22 Jul 2021 14:19:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33046) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m6cyJ-0005Nf-HB for qemu-devel@nongnu.org; Thu, 22 Jul 2021 13:58:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:22582) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m6cyH-0006BX-Ez for qemu-devel@nongnu.org; Thu, 22 Jul 2021 13:58:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626976736; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+hF+7xtGuVKQZvHq4jyUAcy84OuZgE4buGXnLhdZjuc=; b=HvzFVxs6dkrKj4mdRxHVum+ekkSAsDlobdAVFRJ62p+Tj5pBpbbPm1AGgw7KPTgMenKKuL dIk96R5dgMHUs/AH3w0gYuJLAQxyZYxgAn/tJMyvieUEGwE+/I7SyhgNxFHQho39HynYLM wASD4dDR0uCX/OlWVv7GnhMeP2MsIrY= Received: from mail-qv1-f72.google.com (mail-qv1-f72.google.com [209.85.219.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-65-1ReLYlKnMc6uTWDjBCGYdQ-1; Thu, 22 Jul 2021 13:58:55 -0400 X-MC-Unique: 1ReLYlKnMc6uTWDjBCGYdQ-1 Received: by mail-qv1-f72.google.com with SMTP id h12-20020a0562140dacb029030449450d37so80359qvh.14 for ; Thu, 22 Jul 2021 10:58:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+hF+7xtGuVKQZvHq4jyUAcy84OuZgE4buGXnLhdZjuc=; b=r6vtYJS0+bGK9d99z/5yiiulVB9yWg2GmjE3QUCaZ9i1OXOAdrJhce+rPp7DVVCLgI +mkqLnlZ1YmSZZQNWoOa0OWeteg6IH0ZUk+MplOc00MtJUrELysvwihDUIjKzI2HTxjf K37bk5RWJjYrwUTeaxhpD6CmscBTAaazLln81iL5pf0O8pM1hmFJHb6FA0jgsi6VAXgN wZju1Dm2rbQiqv/K5X8zszcjolJEwqgbartEbgKOxtW4pUtPNrdhLcHytfBcAght0LCJ pc0VMlAQnrM+7Dy9k+6ktQhFf1YemiX8JYXM2TU+Jz5YRC8IbmznBOBoZMMcxWjljyTz ubDA== X-Gm-Message-State: AOAM530hlFOl/gAN6ojvAepENa04z5kq0dUXOF/WH5G8A+cBktOwO+6W rjXQo8/XjxcUKM40+86JLuyJ904u57+pChykfVRLHp/UjTjo9cUrBpwT8XxEt9VwdZI8WYSdBvr c5PgV/5bN4EeiG3ts3TCeR8BLvmJQzlM8G8CByj4+47PXbIE2SCMzbMD/CFTmcabC X-Received: by 2002:a37:9d41:: with SMTP id g62mr818075qke.55.1626976734725; Thu, 22 Jul 2021 10:58:54 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzPDkGswJTWHrh+SgGCfBUU+nwisKOl4U0VYZQMEGU2toXXt4WforeUhhFFQhYfv/RerP84MQ== X-Received: by 2002:a37:9d41:: with SMTP id g62mr818045qke.55.1626976734453; Thu, 22 Jul 2021 10:58:54 -0700 (PDT) Received: from localhost.localdomain (bras-base-toroon474qw-grc-65-184-144-111-238.dsl.bell.ca. [184.144.111.238]) by smtp.gmail.com with ESMTPSA id j20sm10418018qtq.14.2021.07.22.10.58.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Jul 2021 10:58:53 -0700 (PDT) From: Peter Xu To: qemu-devel@nongnu.org Subject: [PATCH v3 5/5] migration: Move the yank unregister of channel_close out Date: Thu, 22 Jul 2021 13:58:41 -0400 Message-Id: <20210722175841.938739-6-peterx@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210722175841.938739-1-peterx@redhat.com> References: <20210722175841.938739-1-peterx@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=peterx@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=216.205.24.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.472, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Lukas Straub , "Daniel P . Berrange" , Juan Quintela , "Dr . David Alan Gilbert" , peterx@redhat.com, Leonardo Bras Soares Passos , Eric Blake Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" It's efficient, but hackish to call yank unregister calls in channel_close(), especially it'll be hard to debug when qemu crashed with some yank function leaked. Remove that hack, but instead explicitly unregister yank functions at the places where needed, they are: (on src) - migrate_fd_cleanup - postcopy_pause (on dst) - migration_incoming_state_destroy - postcopy_pause_incoming Signed-off-by: Peter Xu --- migration/migration.c | 14 +++++++++++++- migration/qemu-file-channel.c | 3 --- migration/savevm.c | 7 +++++++ migration/yank_functions.c | 14 ++++++++++++++ migration/yank_functions.h | 1 + 5 files changed, 35 insertions(+), 4 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index b2c48b7e17..a50330016c 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -59,6 +59,7 @@ #include "multifd.h" #include "qemu/yank.h" #include "sysemu/cpus.h" +#include "yank_functions.h" #define MAX_THROTTLE (128 << 20) /* Migration transfer speed throttling */ @@ -273,6 +274,7 @@ void migration_incoming_state_destroy(void) } if (mis->from_src_file) { + migration_ioc_unregister_yank_from_file(mis->from_src_file); qemu_fclose(mis->from_src_file); mis->from_src_file = NULL; } @@ -1811,6 +1813,7 @@ static void migrate_fd_cleanup(MigrationState *s) * Close the file handle without the lock to make sure the * critical section won't block for long. */ + migration_ioc_unregister_yank_from_file(tmp); qemu_fclose(tmp); } @@ -3351,8 +3354,17 @@ static MigThrError postcopy_pause(MigrationState *s) while (true) { QEMUFile *file; - /* Current channel is possibly broken. Release it. */ + /* + * Current channel is possibly broken. Release it. Note that this is + * guaranteed even without lock because to_dst_file should only be + * modified by the migration thread. That also guarantees that the + * unregister of yank is safe too without the lock. It should be safe + * even to be within the qemu_file_lock, but we didn't do that to avoid + * taking more mutex (yank_lock) within qemu_file_lock. TL;DR: we make + * the qemu_file_lock critical section as small as possible. + */ assert(s->to_dst_file); + migration_ioc_unregister_yank_from_file(s->to_dst_file); qemu_mutex_lock(&s->qemu_file_lock); file = s->to_dst_file; s->to_dst_file = NULL; diff --git a/migration/qemu-file-channel.c b/migration/qemu-file-channel.c index 2f8b1fcd46..bb5a5752df 100644 --- a/migration/qemu-file-channel.c +++ b/migration/qemu-file-channel.c @@ -107,9 +107,6 @@ static int channel_close(void *opaque, Error **errp) int ret; QIOChannel *ioc = QIO_CHANNEL(opaque); ret = qio_channel_close(ioc, errp); - if (OBJECT(ioc)->ref == 1) { - migration_ioc_unregister_yank(ioc); - } object_unref(OBJECT(ioc)); return ret; } diff --git a/migration/savevm.c b/migration/savevm.c index 96b5e5d639..7b7b64bd13 100644 --- a/migration/savevm.c +++ b/migration/savevm.c @@ -65,6 +65,7 @@ #include "qemu/bitmap.h" #include "net/announce.h" #include "qemu/yank.h" +#include "yank_functions.h" const unsigned int postcopy_ram_discard_version; @@ -2568,6 +2569,12 @@ static bool postcopy_pause_incoming(MigrationIncomingState *mis) /* Clear the triggered bit to allow one recovery */ mis->postcopy_recover_triggered = false; + /* + * Unregister yank with either from/to src would work, since ioc behind it + * is the same + */ + migration_ioc_unregister_yank_from_file(mis->from_src_file); + assert(mis->from_src_file); qemu_file_shutdown(mis->from_src_file); qemu_fclose(mis->from_src_file); diff --git a/migration/yank_functions.c b/migration/yank_functions.c index 23697173ae..8c08aef14a 100644 --- a/migration/yank_functions.c +++ b/migration/yank_functions.c @@ -14,6 +14,7 @@ #include "qemu/yank.h" #include "io/channel-socket.h" #include "io/channel-tls.h" +#include "qemu-file.h" void migration_yank_iochannel(void *opaque) { @@ -46,3 +47,16 @@ void migration_ioc_unregister_yank(QIOChannel *ioc) QIO_CHANNEL(ioc)); } } + +void migration_ioc_unregister_yank_from_file(QEMUFile *file) +{ + QIOChannel *ioc = qemu_file_get_ioc(file); + + if (ioc) { + /* + * For migration qemufiles, we'll always reach here. Though we'll skip + * calls from e.g. savevm/loadvm as they don't use yank. + */ + migration_ioc_unregister_yank(ioc); + } +} diff --git a/migration/yank_functions.h b/migration/yank_functions.h index 74c7f18c91..a7577955ed 100644 --- a/migration/yank_functions.h +++ b/migration/yank_functions.h @@ -17,3 +17,4 @@ void migration_yank_iochannel(void *opaque); void migration_ioc_register_yank(QIOChannel *ioc); void migration_ioc_unregister_yank(QIOChannel *ioc); +void migration_ioc_unregister_yank_from_file(QEMUFile *file); -- 2.31.1