From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 34ED51FF143 for ; Mon, 02 Feb 2026 14:20:24 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id B90D25E8B; Mon, 2 Feb 2026 14:20:53 +0100 (CET) Message-ID: <37527a80-51b7-4b16-b2a8-a1b1c0a66664@proxmox.com> Date: Mon, 2 Feb 2026 14:20:18 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 proxmox-backup 07/16] api: backup: make fixed index file size optional To: Christian Ebner , pbs-devel@lists.proxmox.com References: <20260130164552.281581-1-r.obkircher@proxmox.com> <20260130164552.281581-8-r.obkircher@proxmox.com> Content-Language: en-US, de-AT From: Robert Obkircher In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1770038345433 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.055 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 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: 5UG5MWROEAIUERTWHMYO43GFOUOL2BDQ X-Message-ID-Hash: 5UG5MWROEAIUERTWHMYO43GFOUOL2BDQ X-MailFrom: r.obkircher@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 2/2/26 12:38, Christian Ebner wrote: > On 1/30/26 5:45 PM, Robert Obkircher wrote: >> Pass the optional size to the FixedIndexWriter to make it grow as >> necessary. >> >> Signed-off-by: Robert Obkircher >> --- >>   src/api2/backup/environment.rs | 21 ++++++++++++--------- >>   src/api2/backup/mod.rs         |  8 +++----- >>   2 files changed, 15 insertions(+), 14 deletions(-) >> >> diff --git a/src/api2/backup/environment.rs >> b/src/api2/backup/environment.rs >> index bd9c5211..90a84ed2 100644 >> --- a/src/api2/backup/environment.rs >> +++ b/src/api2/backup/environment.rs >> @@ -67,7 +67,7 @@ struct DynamicWriterState { >>   struct FixedWriterState { >>       name: String, >>       index: FixedIndexWriter, >> -    size: usize, >> +    size: Option, >>       chunk_size: u32, >>       chunk_count: u64, >>       small_chunk_count: usize, // allow 0..1 small chunks (last >> chunk may be smaller) >> @@ -349,7 +349,7 @@ impl BackupEnvironment { >>           &self, >>           index: FixedIndexWriter, >>           name: String, >> -        size: usize, >> +        size: Option, >>           chunk_size: u32, >>           incremental: bool, >>       ) -> Result { >> @@ -443,6 +443,7 @@ impl BackupEnvironment { >>           } >>             let end = (offset as usize) + (size as usize); >> +        data.index.grow_to_size(end)?; >>           let idx = data.index.check_chunk_alignment(end, size as >> usize)?; >>             data.chunk_count += 1; >> @@ -624,13 +625,15 @@ impl BackupEnvironment { >>                   ); >>               } >>   -            if size != (data.size as u64) { >> -                bail!( >> -                    "fixed writer '{}' close failed - unexpected >> file size ({} != {})", >> -                    data.name, >> -                    data.size, >> -                    size >> -                ); >> +            if let Some(known_size) = data.size { >> +                if size != known_size as u64 { >> +                    bail!( >> +                        "fixed writer '{}' close failed - >> unexpected file size ({} != {})", >> +                        data.name, >> +                        known_size, >> +                        size, >> +                    ); >> +                } >>               } >>           } >>   diff --git a/src/api2/backup/mod.rs b/src/api2/backup/mod.rs >> index c625a2dc..c2822c18 100644 >> --- a/src/api2/backup/mod.rs >> +++ b/src/api2/backup/mod.rs >> @@ -456,7 +456,7 @@ pub const API_METHOD_CREATE_FIXED_INDEX: >> ApiMethod = ApiMethod::new( >>               ("archive-name", false, &BACKUP_ARCHIVE_NAME_SCHEMA), >>               ( >>                   "size", >> -                false, >> +                true, >>                   &IntegerSchema::new("File >> size.").minimum(1).schema() >>               ), >>               ( >> @@ -480,7 +480,7 @@ fn create_fixed_index( >>       let env: &BackupEnvironment = rpcenv.as_ref(); >>         let name = required_string_param(¶m, >> "archive-name")?.to_owned(); >> -    let size = required_integer_param(¶m, "size")? as usize; >> +    let size = >> param["size"].as_u64().map(usize::try_from).transpose()?; >>       let reuse_csum = param["reuse-csum"].as_str(); > > The fixed index writer does not allow for incremental backups, > failing if it is requested. > > question: should we allow to proceed the backup without failing by > simply switching to a non incremental backup for those index writers > where no size is specified, including a log warning that that a > non-incremental mode is used?  I think reuse-csum without size could reasonably be supported by copying the entire file and taking the size from there. Now that add_chunk is a single operation it would even be possible to allow overwriting the partial chunk in the end to continue growing. > > Should be better than failing the whole backup snapshot in case of > multiple archives with mixed inputs. As far as I can tell, "reuse-csum" is only set in one specific place in proxmox-backup-qemu and only if the checksum matches exactly. Is this actually relevant for anything else? > >>         let archive_name = name.clone(); >> @@ -528,9 +528,7 @@ fn create_fixed_index( >>           reader = Some(index); >>       } >>   -    let mut writer = env >> -        .datastore >> -        .create_fixed_writer(&path, Some(size), chunk_size)?; >> +    let mut writer = env.datastore.create_fixed_writer(&path, >> size, chunk_size)?; >>         if let Some(reader) = reader { >>           writer.clone_data_from(&reader)?; >