From nobody Mon Feb 9 17:36:50 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=suse.de ARC-Seal: i=1; a=rsa-sha256; t=1693507256; cv=none; d=zohomail.com; s=zohoarc; b=UVvatj7WGC0dTkZzkL/WyCnDY1wY4lo0+CaPGq4KdqfQvvW3z9DV/SAmNQ0fqoiXiyg6XE7jK4kRLCgdp3al7L48s1q/VD8c9VdcRVjvWo3h76VFYORv0SW6tYsn7gkRxr1M/k4It+BUwfyqwaTlYuWaHJdv4pxhcDUJ31AEe3I= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1693507256; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=ratvuBX3qQ91vHO0LxE42YTYPtTJVqto9t43u0ml8kE=; b=WUMB/0re1P35vfeMsWCD/jqxDvvaxfe7DGBdm/q23rdUPCu/qIfI38ncmhN1Rq6LPRu/pz2lf2TgEVshj2xekIfCg1OU9+EnllPZzd3k7Y49BcwFktfLval5d9P4V0AoXTB+z4XOXeV5s4avOzYrbG00GhPZXDbxYXw/M8lfIEg= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1693507256716538.2204201123054; Thu, 31 Aug 2023 11:40:56 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qbma4-0001tr-8a; Thu, 31 Aug 2023 14:39:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qbmZl-0001di-PD for qemu-devel@nongnu.org; Thu, 31 Aug 2023 14:39:33 -0400 Received: from smtp-out1.suse.de ([2001:67c:2178:6::1c]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qbmZj-0002FZ-J5 for qemu-devel@nongnu.org; Thu, 31 Aug 2023 14:39:29 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 77FBD2185E; Thu, 31 Aug 2023 18:39:26 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id F3F2C13583; Thu, 31 Aug 2023 18:39:24 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id CILYLlze8GQhPgAAMHmgww (envelope-from ); Thu, 31 Aug 2023 18:39:24 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1693507166; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ratvuBX3qQ91vHO0LxE42YTYPtTJVqto9t43u0ml8kE=; b=A2fTGlOeOOIIbAXOt/LAdFenSrik8D+MnULgZRrI7O+HWOdeDJGYl9esJLhUuhM7xUjaKc F4xPr7mlA21HZrLHY4qJmbBKmVy60U2Cn5wEyvb3M/t2pMi3rMFbGljNdaGld6Wh+aDJxY JFxnDGAlxN9p7Ry28S0yG9Vq++1htFo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1693507166; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ratvuBX3qQ91vHO0LxE42YTYPtTJVqto9t43u0ml8kE=; b=KDSq3fCW3nEtgRRLS2LOAXLyxOQ9SwHpI+FK/Mj6VbpSeZpUiXFE5DM/U8kwOMyDKBKsSd pLFpGuxXcsl6wfCw== From: Fabiano Rosas To: qemu-devel@nongnu.org Cc: Juan Quintela , Peter Xu , Wei Wang , Leonardo Bras Subject: [PATCH v5 3/8] migration: Fix possible race when shutting down to_dst_file Date: Thu, 31 Aug 2023 15:39:11 -0300 Message-Id: <20230831183916.13203-4-farosas@suse.de> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230831183916.13203-1-farosas@suse.de> References: <20230831183916.13203-1-farosas@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2001:67c:2178:6::1c; envelope-from=farosas@suse.de; helo=smtp-out1.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, 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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @suse.de) X-ZM-MESSAGEID: 1693507258891100005 Content-Type: text/plain; charset="utf-8" It's not safe to call qemu_file_shutdown() on the to_dst_file without first checking for the file's presence under the lock. The cleanup of this file happens at postcopy_pause() and migrate_fd_cleanup() which are not necessarily running in the same thread as migrate_fd_cancel(). Reviewed-by: Peter Xu Signed-off-by: Fabiano Rosas --- migration/migration.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 85c171f32c..5e6a766235 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1245,7 +1245,7 @@ static void migrate_fd_error(MigrationState *s, const= Error *error) static void migrate_fd_cancel(MigrationState *s) { int old_state ; - QEMUFile *f =3D migrate_get_current()->to_dst_file; + trace_migrate_fd_cancel(); =20 WITH_QEMU_LOCK_GUARD(&s->qemu_file_lock) { @@ -1271,11 +1271,13 @@ static void migrate_fd_cancel(MigrationState *s) * If we're unlucky the migration code might be stuck somewhere in a * send/write while the network has failed and is waiting to timeout; * if we've got shutdown(2) available then we can force it to quit. - * The outgoing qemu file gets closed in migrate_fd_cleanup that is - * called in a bh, so there is no race against this cancel. */ - if (s->state =3D=3D MIGRATION_STATUS_CANCELLING && f) { - qemu_file_shutdown(f); + if (s->state =3D=3D MIGRATION_STATUS_CANCELLING) { + WITH_QEMU_LOCK_GUARD(&s->qemu_file_lock) { + if (s->to_dst_file) { + qemu_file_shutdown(s->to_dst_file); + } + } } if (s->state =3D=3D MIGRATION_STATUS_CANCELLING && s->block_inactive) { Error *local_err =3D NULL; @@ -1519,12 +1521,14 @@ void qmp_migrate_pause(Error **errp) { MigrationState *ms =3D migrate_get_current(); MigrationIncomingState *mis =3D migration_incoming_get_current(); - int ret; + int ret =3D 0; =20 if (ms->state =3D=3D MIGRATION_STATUS_POSTCOPY_ACTIVE) { /* Source side, during postcopy */ qemu_mutex_lock(&ms->qemu_file_lock); - ret =3D qemu_file_shutdown(ms->to_dst_file); + if (ms->to_dst_file) { + ret =3D qemu_file_shutdown(ms->to_dst_file); + } qemu_mutex_unlock(&ms->qemu_file_lock); if (ret) { error_setg(errp, "Failed to pause source migration"); --=20 2.35.3