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 53A421FF13F for ; Thu, 12 Feb 2026 16:00:15 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 03727129D7; Thu, 12 Feb 2026 16:00:58 +0100 (CET) From: Fiona Ebner To: pve-devel@lists.proxmox.com Subject: [PATCH qemu-server] blockdev: commit: improve comment about completion mode Date: Thu, 12 Feb 2026 16:00:10 +0100 Message-ID: <20260212150017.459434-1-f.ebner@proxmox.com> X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1770908418234 X-SPAM-LEVEL: Spam detection results: 0 AWL -0.016 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 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 Message-ID-Hash: 5H5HE6BFRFCZV2IGFK3BIASK6NM5WHAN X-Message-ID-Hash: 5H5HE6BFRFCZV2IGFK3BIASK6NM5WHAN X-MailFrom: f.ebner@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: For reference, see the QMP docs [0][1]. [0]: https://qemu.readthedocs.io/en/master/interop/qemu-qmp-ref.html#command-QMP-block-core.block-commit [1]: https://qemu.readthedocs.io/en/master/interop/qemu-qmp-ref.html#command-QMP-job.job-complete Signed-off-by: Fiona Ebner --- src/PVE/QemuServer/Blockdev.pm | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/src/PVE/QemuServer/Blockdev.pm b/src/PVE/QemuServer/Blockdev.pm index af7e769b..8eb01b45 100644 --- a/src/PVE/QemuServer/Blockdev.pm +++ b/src/PVE/QemuServer/Blockdev.pm @@ -1074,7 +1074,15 @@ sub blockdev_commit { mon_cmd($vmid, "block-commit", %$opts); $jobs->{$job_id} = {}; - # if we commit the current, the blockjob need to be in 'complete' mode + # If the 'current' state is committed to its backing snapshot, the job will not complete + # automatically, because there is a writer, i.e. the guest. It is necessary to use the + # 'complete' completion mode, so that the 'current' block node is replaced with the backing + # node upon completion. Like that, IO after the commit operation will already land in the + # backing node, which will be renamed since it will be the new top of the chain (done by the + # caller). + # + # For other snapshots in the chain, it can be assumed that they have no writer, so + # 'block-commit' will complete automatically. my $complete = $src_snap && $src_snap ne 'current' ? 'auto' : 'complete'; eval { -- 2.47.3