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 C03D11FF144 for ; Tue, 24 Mar 2026 14:29:50 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 3CD3811AC6; Tue, 24 Mar 2026 14:30:09 +0100 (CET) Message-ID: Date: Tue, 24 Mar 2026 14:30:03 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH proxmox-backup] pbs-key-config: align fsync behavior when storing new/existing key To: =?UTF-8?Q?Fabian_Gr=C3=BCnbichler?= , pbs-devel@lists.proxmox.com References: <20260324100413.215443-1-c.ebner@proxmox.com> <1774358207.bh0j523o7r.astroid@yuna.none> Content-Language: en-US, de-DE From: Christian Ebner In-Reply-To: <1774358207.bh0j523o7r.astroid@yuna.none> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1774358957391 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.060 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: NBAUU6NGY3NZZPSWWZRKKOR2JPHELI3U X-Message-ID-Hash: NBAUU6NGY3NZZPSWWZRKKOR2JPHELI3U X-MailFrom: c.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 Backup Server development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 3/24/26 2:16 PM, Fabian Grünbichler wrote: > On March 24, 2026 11:04 am, Christian Ebner wrote: >> In case a key is stored by replacing the file contents, the file >> contents are synced to disk as the corresponding flag is set for >> proxmox-sys::fs::replace_file(). When creating a new file however, >> fsync is never called. >> >> Align the behaviour by also calling fsync in case of storing the key >> to a new file. >> >> Signed-off-by: Christian Ebner >> --- >> Noticed while evaluating to reuse this method to store key >> information to be used by push sync jobs. >> >> pbs-key-config/src/lib.rs | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/pbs-key-config/src/lib.rs b/pbs-key-config/src/lib.rs >> index 0bcd5338c..71a49dd78 100644 >> --- a/pbs-key-config/src/lib.rs >> +++ b/pbs-key-config/src/lib.rs >> @@ -1,5 +1,6 @@ >> use std::io::Write; >> use std::path::Path; >> +use std::os::fd::AsRawFd; >> >> use anyhow::{bail, format_err, Context, Error}; >> use serde::{Deserialize, Serialize}; >> @@ -254,6 +255,7 @@ impl KeyConfig { >> .open(path)?; >> >> file.write_all(data.as_bytes())?; >> + nix::unistd::fsync(file.as_raw_fd())?; > > LGTM in principle, though we could also switch to > atomic_open_or_create_file ? Had a look at that as well, that would however create a tempfile first. And since we do already have the open file descriptor here and handle failure on per-existing files here as expected (which would require adding `OFlag::O_EXCL` in the other case), I did not consider this further, simply calling fsync seemed the better option for this particular case.