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=-13.6 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 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 AC53EC432BE for ; Mon, 26 Jul 2021 12:49:10 +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 4FB4B60F45 for ; Mon, 26 Jul 2021 12:49:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 4FB4B60F45 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]:43226 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m802f-00009Y-H7 for qemu-devel@archiver.kernel.org; Mon, 26 Jul 2021 08:49:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44550) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m7zyL-0001gf-FA for qemu-devel@nongnu.org; Mon, 26 Jul 2021 08:44:41 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:41905) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m7zyJ-00089w-LC for qemu-devel@nongnu.org; Mon, 26 Jul 2021 08:44:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627303479; 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=8KVqPMCmcEXoYQlwYkqd9YGtwnCkdLCYcKuTtdht7dw=; b=BtbR/MKJAkqk4MyBPLEgmW382mIPSAvA7fy5n43+tJNwdppHVhC3mxum0qBl6vAlvGPqdK 2guirMG42GrS83u+YkePCk60+ZN7Z3IWYW2/OtbdiuzAYJUlvmbrHH9oW1jhPcwGpv8VBU H7+toDWscAHmeC1cwIeK9GLgFChNEIE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-332-GAHFusUwNKmYHYeJk5kaFg-1; Mon, 26 Jul 2021 08:44:37 -0400 X-MC-Unique: GAHFusUwNKmYHYeJk5kaFg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 78C19802CBE; Mon, 26 Jul 2021 12:44:36 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-113-117.ams2.redhat.com [10.36.113.117]) by smtp.corp.redhat.com (Postfix) with ESMTP id 60D1A60C81; Mon, 26 Jul 2021 12:44:13 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, wei.w.wang@intel.com, peterx@redhat.com Subject: [PULL 6/7] migration: Move the yank unregister of channel_close out Date: Mon, 26 Jul 2021 13:43:30 +0100 Message-Id: <20210726124331.124710-7-dgilbert@redhat.com> In-Reply-To: <20210726124331.124710-1-dgilbert@redhat.com> References: <20210726124331.124710-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@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=170.10.133.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.717, 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: berrange@redhat.com, leobras@redhat.com, david@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Peter Xu 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 Message-Id: <20210722175841.938739-6-peterx@redhat.com> Reviewed-by: Lukas Straub Signed-off-by: Dr. David Alan Gilbert --- 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 62dbcb7d52..041b8451a6 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