From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 04C101FF16B for ; Fri, 26 Sep 2025 10:42:11 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 5F434B006; Fri, 26 Sep 2025 10:42:43 +0200 (CEST) From: Christian Ebner To: pbs-devel@lists.proxmox.com Date: Fri, 26 Sep 2025 10:42:19 +0200 Message-ID: <20250926084221.201116-1-c.ebner@proxmox.com> X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1758876144816 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.043 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment KAM_SHORT 0.001 Use of a URL Shortener for very short URL RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_RPBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. RCVD_IN_VALIDITY_SAFE_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. See https://knowledge.validity.com/hc/en-us/articles/20961730681243 for more information. SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [docs.rs, environment.rs, proxmox.com] Subject: [pbs-devel] [PATCH proxmox-backup v2 0/2] fix #6750: fix possible deadlock for s3 backed datastore backups X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Proxmox Backup Server development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pbs-devel-bounces@lists.proxmox.com Sender: "pbs-devel" These patches aim to fix a deadlock which can occur during backup jobs to datastores backed by S3 backend. The deadlock most likely is caused by the mutex guard for the backup shared state being held while entering the tokio::task::block_in_place context and executing async code, which however can lead to deadlocks as described in [0]. Therefore, these patches avoid holding the mutex guard for the shared backup state while performing the s3 backend operations, by prematurely dropping it. To avoid inconsistencies, introduce flags to keep track of the index writers closing state and add a transient `Finishing` state to be entered during manifest updates. Changes since version 1 (thanks @Fabian): - Use the shared backup state's writers in addition with a closed flag instead of counting active backend operations. - Replace finished flag with BackupState enum to introduce the new, transient `Finishing` state to be entered during manifest updates. - Add missing checks and refactor code to the now mutable reference when accessing the shared backup state in the respective close calls. [0] https://docs.rs/tokio/latest/tokio/sync/struct.Mutex.html#which-kind-of-mutex-should-you-use Link to the bugtracker issue: https://bugzilla.proxmox.com/show_bug.cgi?id=6750 Another report in the community forum: https://forum.proxmox.com/threads/171422/ proxmox-backup: Christian Ebner (2): fix #6750: api: avoid possible deadlock on datastores with s3 backend api: backup: never hold mutex guard when doing manifest update src/api2/backup/environment.rs | 169 +++++++++++++++++++++++---------- 1 file changed, 120 insertions(+), 49 deletions(-) Summary over all repositories: 1 files changed, 120 insertions(+), 49 deletions(-) -- Generated by git-murpp 0.8.1 _______________________________________________ pbs-devel mailing list pbs-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel