From patchwork Fri Sep 6 11:12:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13794029 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 73F91CD5BDD for ; Fri, 6 Sep 2024 11:23:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1smWxt-0000nR-ND; Fri, 06 Sep 2024 07:17:22 -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 1smWxC-0006bn-C5; Fri, 06 Sep 2024 07:16:40 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1smWx9-00086r-RK; Fri, 06 Sep 2024 07:16:37 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id E44EB8C494; Fri, 6 Sep 2024 14:12:08 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id E416C1336FE; Fri, 6 Sep 2024 14:13:26 +0300 (MSK) Received: (nullmailer pid 353660 invoked by uid 1000); Fri, 06 Sep 2024 11:13:24 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Fabiano Rosas , Jim Fehlig , Peter Xu , Michael Tokarev Subject: [Stable-9.0.3 36/69] migration/multifd: Fix multifd_send_setup cleanup when channel creation fails Date: Fri, 6 Sep 2024 14:12:45 +0300 Message-Id: <20240906111324.353230-36-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Fabiano Rosas When a channel fails to create, the code currently just returns. This is wrong for two reasons: 1) Channel n+1 will not get to initialize it's semaphores, leading to an assert when terminate_threads tries to post to it: qemu-system-x86_64: ../util/qemu-thread-posix.c:92: qemu_mutex_lock_impl: Assertion `mutex->initialized' failed. 2) (theoretical) If channel n-1 already started creation it will defeat the purpose of the channels_created logic which is in place to avoid migrate_fd_cleanup() to run while channels are still being created. This cannot really happen today because the current failure cases for multifd_new_send_channel_create() are all synchronous, resulting from qio_channel_file_new_path() getting a bad filename. This would hit all channels equally. But I don't want to set a trap for future people, so have all channels try to create (even if failing), and only fail after the channels_created semaphore has been posted. While here, remove the error_report_err call. There's one already at migrate_fd_cleanup later on. Cc: qemu-stable@nongnu.org Reported-by: Jim Fehlig Fixes: b7b03eb614 ("migration/multifd: Add outgoing QIOChannelFile support") Reviewed-by: Peter Xu Signed-off-by: Fabiano Rosas (cherry picked from commit 0bd5b9284fa94a6242a0d27a46380d93e753488b) Signed-off-by: Michael Tokarev diff --git a/migration/multifd.c b/migration/multifd.c index 2802afe79d..fa55586f89 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -1145,7 +1145,6 @@ static bool multifd_new_send_channel_create(gpointer opaque, Error **errp) bool multifd_send_setup(void) { MigrationState *s = migrate_get_current(); - Error *local_err = NULL; int thread_count, ret = 0; uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); bool use_packets = multifd_use_packets(); @@ -1166,6 +1165,7 @@ bool multifd_send_setup(void) for (i = 0; i < thread_count; i++) { MultiFDSendParams *p = &multifd_send_state->params[i]; + Error *local_err = NULL; qemu_sem_init(&p->sem, 0); qemu_sem_init(&p->sem_sync, 0); @@ -1190,7 +1190,8 @@ bool multifd_send_setup(void) p->write_flags = 0; if (!multifd_new_send_channel_create(p, &local_err)) { - return false; + migrate_set_error(s, local_err); + ret = -1; } } @@ -1203,24 +1204,27 @@ bool multifd_send_setup(void) qemu_sem_wait(&multifd_send_state->channels_created); } + if (ret) { + goto err; + } + for (i = 0; i < thread_count; i++) { MultiFDSendParams *p = &multifd_send_state->params[i]; + Error *local_err = NULL; ret = multifd_send_state->ops->send_setup(p, &local_err); if (ret) { - break; + migrate_set_error(s, local_err); + goto err; } } - if (ret) { - migrate_set_error(s, local_err); - error_report_err(local_err); - migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, - MIGRATION_STATUS_FAILED); - return false; - } - return true; + +err: + migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, + MIGRATION_STATUS_FAILED); + return false; } bool multifd_recv(void)