From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [45.144.208.40]) by lore.proxmox.com (Postfix) with ESMTPS id 774C11FF0E7 for ; Fri, 10 Jul 2026 13:37:05 +0200 (CEST) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id 0A4242144D; Fri, 10 Jul 2026 13:37:04 +0200 (CEST) Message-ID: Date: Fri, 10 Jul 2026 13:36:03 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH datacenter-manager 15/15] task cache: handle potentially duplicated archive files after 'compress_archive_file' To: Lukas Wagner , pdm-devel@lists.proxmox.com References: <20260702092258.174740-1-l.wagner@proxmox.com> <20260702092258.174740-16-l.wagner@proxmox.com> Content-Language: en-US From: Dominik Csapak In-Reply-To: <20260702092258.174740-16-l.wagner@proxmox.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1783683352418 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.054 Adjusted score from AWL reputation of From: address DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) 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: IEGGWA6Z2M46QURMND2GIWHT5QNGYLTM X-Message-ID-Hash: IEGGWA6Z2M46QURMND2GIWHT5QNGYLTM X-MailFrom: d.csapak@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 Datacenter Manager development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: comment inline On 7/2/26 11:23 AM, Lukas Wagner wrote: > `compress_archive_file` cannot be made fully atomic, therefore we must > consider the case where we have both, the old, uncompressed file and the > new, compressed file in the archive directory. > > This is handled by ignoring duplicates files when reading/writing > from/into the task archive, and by actively cleaning up the duplicates > during `rotate`. > > Signed-off-by: Lukas Wagner > --- > server/src/remote_tasks/task_cache.rs | 97 +++++++++++++++++++++++++-- > 1 file changed, 93 insertions(+), 4 deletions(-) > > diff --git a/server/src/remote_tasks/task_cache.rs b/server/src/remote_tasks/task_cache.rs > index 23238cca..2110037b 100644 > --- a/server/src/remote_tasks/task_cache.rs > +++ b/server/src/remote_tasks/task_cache.rs > @@ -289,13 +289,34 @@ impl<'a> WritableTaskCache<'a> { > Ok(file) > } > > - /// Rotate task archive if the the newest archive file is older than `rotate_after`. > + /// Rotate task archive if the newest archive file is older than `rotate_after`. > /// > /// The oldest archive files are removed if the total number of archive files exceeds > /// `max_files`. `now` is supposed to be a UNIX timestamp (seconds). > + /// > + /// If there are any duplicate archive files (can happen if `compress` is interrupted at the > + /// wrong time), the uncompressed version is deleted. > pub fn rotate(&self, now: i64) -> Result { > let mut did_rotate = false; > - let mut archive_files = self.cache.archive_files(&self.lock)?; > + let archive_files_with_dupes = self.cache.archive_files_with_dupes(&self.lock)?; > + > + let mut deduped: Vec = Vec::new(); > + > + for file in archive_files_with_dupes { > + if deduped.iter().any(|e| e.starttime == file.starttime) { > + // Found dupe, remove it. > + if let Err(err) = std::fs::remove_file(&file.path) { > + log::error!( > + "could not clean up duplicate archive file '{path}': {err}", > + path = file.path.display() > + ) > + } > + } else { > + deduped.push(file); > + } > + } i think we could avoid this double loop here if we use a hashset? also we only detect duplicates by the starttime? sound a bit strange to me, wouldn't the more natural way by looking at e.g. the filenames? > + > + let mut archive_files = deduped; > > let mut start_new_file = |files: &mut Vec| -> Result<(), Error> { > let new_file = self.new_file(now, self.cache.uncompressed_files == 0)?; > @@ -848,6 +869,11 @@ impl<'a> WritableTaskCache<'a> { > return Err(err); > } > > + // If we crash here or if `remove_file` fails, we might end up with the original, > + // uncompressed file as well as the new, compressed file. `archive_files` filters > + // duplicates out, so we should never read from the duplicated file. Any left-over > + // duplicates are cleaned during `rotate`. > + > std::fs::remove_file(&file.path).context("failed to remove uncompressed archive file")?; > > Ok(file_state) > @@ -970,7 +996,7 @@ impl TaskCache { > /// cut-off timestamp. The result is sorted ascending by cut-off timestamp (most recent one > /// first). > /// The task archive should be locked for reading when calling this function. > - fn archive_files(&self, _lock: &TaskCacheLock) -> Result, Error> { > + fn archive_files_with_dupes(&self, _lock: &TaskCacheLock) -> Result, Error> { > let mut names = Vec::new(); > > for entry in std::fs::read_dir(&self.base_path)? { > @@ -983,7 +1009,23 @@ impl TaskCache { > } > } > > - names.sort_by_key(|e| -e.starttime); > + names.sort_by(|a, b| { > + b.starttime > + .cmp(&a.starttime) > + .then(b.compressed.cmp(&a.compressed)) > + }); > + > + Ok(names) > + } > + > + /// Returns a list of existing archive files, together with their respective > + /// cut-off timestamp. The result is sorted ascending by cut-off timestamp (most recent one > + /// first). Any duplicates (equal starttime but different compression status) are removed. > + /// > + /// The task archive should be locked for reading when calling this function. > + fn archive_files(&self, lock: &TaskCacheLock) -> Result, Error> { > + let mut names = self.archive_files_with_dupes(lock)?; > + names.dedup_by_key(|e| e.starttime); > > Ok(names) > } > @@ -2104,4 +2146,51 @@ mod tests { > "cutoff timestamp should be reset to the lower bound of the corrupted archive file" > ); > } > + > + /// Ensure that if for any reason there exist multiple files with the same start time (only > + /// possible if one of them is compressed and the other one uncompressed), we only return one > + /// of them. Also verify that compressed files are preferred. > + #[test] > + fn dedup_duplicate_archive_files() { > + let (_tmp_dir, mut cache) = make_cache().unwrap(); > + cache.rotate_after = 100; > + cache.uncompressed_files = 1; > + cache.max_files = 3; > + > + let cache = cache.write().unwrap(); > + > + cache.new_file(1000, false).unwrap(); > + cache.new_file(1000, true).unwrap(); > + cache.new_file(2000, true).unwrap(); > + cache.new_file(2000, false).unwrap(); > + > + let files = cache.cache.archive_files(&cache.lock).unwrap(); > + > + assert_eq!(files.len(), 2); > + let first = files.get(0).unwrap(); > + let second = files.get(1).unwrap(); > + > + assert!(first.compressed); > + assert_eq!(first.starttime, 2000); > + > + assert!(second.compressed); > + assert_eq!(second.starttime, 1000); > + > + let files = cache.cache.archive_files_with_dupes(&cache.lock).unwrap(); > + assert_eq!(files.len(), 4); > + > + cache.rotate(2050).unwrap(); > + > + let files = cache.cache.archive_files_with_dupes(&cache.lock).unwrap(); > + assert_eq!(files.len(), 2); > + > + let first = files.get(0).unwrap(); > + let second = files.get(1).unwrap(); > + > + assert!(first.compressed); > + assert_eq!(first.starttime, 2000); > + > + assert!(second.compressed); > + assert_eq!(second.starttime, 1000); > + } > }