Re: [pbs-devel] [PATCH v3 proxmox-backup 44/58] client: pxar: add previous reference to archiver

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

On March 28, 2024 1:36 pm, Christian Ebner wrote:
> Read the previous snaphosts manifest and check if a split archive
> with the same name is given. If so, create the accessor instance to
> read the previous archive entries to be able to lookup and compare
> the metata for the entries, allowing to make a decision if the
> entry is reusable or not.
> 
> Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
> ---
> changes since version 2:
> - renamed accessor to previous metadata_accessor
> - get backup reader for previous snapshot after creating the writer
>   instance for the new snapshot
> - adapted to only use metadata mode for all or non of the given archives
> 
>  pbs-client/src/pxar/create.rs                 | 55 ++++++++++++++++---
>  proxmox-backup-client/src/main.rs             | 51 ++++++++++++++++-
>  .../src/proxmox_restore_daemon/api.rs         |  1 +
>  pxar-bin/src/main.rs                          |  1 +
>  4 files changed, 97 insertions(+), 11 deletions(-)
> 
> diff --git a/pbs-client/src/pxar/create.rs b/pbs-client/src/pxar/create.rs
> index 95a91a59b..79925bba2 100644
> --- a/pbs-client/src/pxar/create.rs
> +++ b/pbs-client/src/pxar/create.rs
> @@ -19,7 +19,7 @@ use nix::sys::stat::{FileStat, Mode};
>  use pathpatterns::{MatchEntry, MatchFlag, MatchList, MatchType, PatternFlag};
>  use pbs_datastore::index::IndexFile;
>  use proxmox_sys::error::SysError;
> -use pxar::accessor::aio::Accessor;
> +use pxar::accessor::aio::{Accessor, Directory};
>  use pxar::encoder::{LinkOffset, PayloadOffset, SeqWrite};
>  use pxar::Metadata;
>  
> @@ -159,7 +159,7 @@ impl ReusedChunks {
>  }
>  
>  /// Pxar options for creating a pxar archive/stream
> -#[derive(Default, Clone)]
> +#[derive(Default)]
>  pub struct PxarCreateOptions {
>      /// Device/mountpoint st_dev numbers that should be included. None for no limitation.
>      pub device_set: Option<HashSet<u64>>,
> @@ -171,6 +171,8 @@ pub struct PxarCreateOptions {
>      pub skip_lost_and_found: bool,
>      /// Skip xattrs of files that return E2BIG error
>      pub skip_e2big_xattr: bool,
> +    /// Reference state for partial backups
> +    pub previous_ref: Option<PxarPrevRef>,
>  }
>  
>  /// Statefull information of previous backups snapshots for partial backups
> @@ -270,6 +272,7 @@ struct Archiver {
>      file_copy_buffer: Vec<u8>,
>      skip_e2big_xattr: bool,
>      reused_chunks: ReusedChunks,
> +    previous_payload_index: Option<DynamicIndexReader>,
>      forced_boundaries: Option<Arc<Mutex<VecDeque<InjectChunks>>>>,
>  }
>  
> @@ -346,6 +349,15 @@ where
>              MatchType::Exclude,
>          )?);
>      }
> +    let (previous_payload_index, previous_metadata_accessor) =
> +        if let Some(refs) = options.previous_ref {
> +            (
> +                Some(refs.payload_index),
> +                refs.accessor.open_root().await.ok(),
> +            )
> +        } else {
> +            (None, None)
> +        };
>  
>      let mut archiver = Archiver {
>          feature_flags,
> @@ -363,11 +375,12 @@ where
>          file_copy_buffer: vec::undefined(4 * 1024 * 1024),
>          skip_e2big_xattr: options.skip_e2big_xattr,
>          reused_chunks: ReusedChunks::new(),
> +        previous_payload_index,
>          forced_boundaries,
>      };
>  
>      archiver
> -        .archive_dir_contents(&mut encoder, source_dir, true)
> +        .archive_dir_contents(&mut encoder, previous_metadata_accessor, source_dir, true)
>          .await?;
>      encoder.finish().await?;
>      encoder.close().await?;
> @@ -399,6 +412,7 @@ impl Archiver {
>      fn archive_dir_contents<'a, T: SeqWrite + Send>(
>          &'a mut self,
>          encoder: &'a mut Encoder<'_, T>,
> +        mut previous_metadata_accessor: Option<Directory<LocalDynamicReadAt<RemoteChunkReader>>>,
>          mut dir: Dir,
>          is_root: bool,
>      ) -> BoxFuture<'a, Result<(), Error>> {
> @@ -433,9 +447,15 @@ impl Archiver {
>  
>                  (self.callback)(&file_entry.path)?;
>                  self.path = file_entry.path;
> -                self.add_entry(encoder, dir_fd, &file_entry.name, &file_entry.stat)
> -                    .await
> -                    .map_err(|err| self.wrap_err(err))?;
> +                self.add_entry(
> +                    encoder,
> +                    &mut previous_metadata_accessor,
> +                    dir_fd,
> +                    &file_entry.name,
> +                    &file_entry.stat,
> +                )
> +                .await
> +                .map_err(|err| self.wrap_err(err))?;
>              }
>              self.path = old_path;
>              self.entry_counter = entry_counter;
> @@ -683,6 +703,7 @@ impl Archiver {
>      async fn add_entry<T: SeqWrite + Send>(
>          &mut self,
>          encoder: &mut Encoder<'_, T>,
> +        previous_metadata: &mut Option<Directory<LocalDynamicReadAt<RemoteChunkReader>>>,
>          parent: RawFd,
>          c_file_name: &CStr,
>          stat: &FileStat,
> @@ -772,7 +793,14 @@ impl Archiver {
>                      catalog.lock().unwrap().start_directory(c_file_name)?;
>                  }
>                  let result = self
> -                    .add_directory(encoder, dir, c_file_name, &metadata, stat)
> +                    .add_directory(
> +                        encoder,
> +                        previous_metadata,
> +                        dir,
> +                        c_file_name,
> +                        &metadata,
> +                        stat,
> +                    )
>                      .await;
>                  if let Some(ref catalog) = self.catalog {
>                      catalog.lock().unwrap().end_directory()?;
> @@ -825,6 +853,7 @@ impl Archiver {
>      async fn add_directory<T: SeqWrite + Send>(
>          &mut self,
>          encoder: &mut Encoder<'_, T>,
> +        previous_metadata_accessor: &mut Option<Directory<LocalDynamicReadAt<RemoteChunkReader>>>,
>          dir: Dir,
>          dir_name: &CStr,
>          metadata: &Metadata,
> @@ -855,7 +884,17 @@ impl Archiver {
>              log::info!("skipping mount point: {:?}", self.path);
>              Ok(())
>          } else {
> -            self.archive_dir_contents(encoder, dir, false).await
> +            let mut dir_accessor = None;
> +            if let Some(accessor) = previous_metadata_accessor.as_mut() {
> +                if let Some(file_entry) = accessor.lookup(dir_name).await? {
> +                    if file_entry.entry().is_dir() {
> +                        let dir = file_entry.enter_directory().await?;
> +                        dir_accessor = Some(dir);
> +                    }
> +                }
> +            }
> +            self.archive_dir_contents(encoder, dir_accessor, dir, false)
> +                .await
>          };
>  
>          self.fs_magic = old_fs_magic;
> diff --git a/proxmox-backup-client/src/main.rs b/proxmox-backup-client/src/main.rs
> index 0b747453c..66dcaa63e 100644
> --- a/proxmox-backup-client/src/main.rs
> +++ b/proxmox-backup-client/src/main.rs
> @@ -688,6 +688,10 @@ fn spawn_catalog_upload(
>                 schema: TRAFFIC_CONTROL_BURST_SCHEMA,
>                 optional: true,
>             },
> +           "change-detection-mode": {
> +               schema: BACKUP_DETECTION_MODE_SPEC,
> +               optional: true,
> +           },
>             "exclude": {
>                 type: Array,
>                 description: "List of paths or patterns for matching files to exclude.",
> @@ -882,6 +886,9 @@ async fn create_backup(
>  
>      let backup_time = backup_time_opt.unwrap_or_else(epoch_i64);
>  
> +    let detection_mode = param["change-detection-mode"].as_str().unwrap_or("data");
> +    let detection_mode = parse_backup_detection_mode_specification(detection_mode)?;
> +
>      let http_client = connect_rate_limited(&repo, rate_limit)?;
>      record_repository(&repo);
>  
> @@ -982,7 +989,7 @@ async fn create_backup(
>          None
>      };
>  
> -    let mut manifest = BackupManifest::new(snapshot);
> +    let mut manifest = BackupManifest::new(snapshot.clone());
>  
>      let mut catalog = None;
>      let mut catalog_result_rx = None;
> @@ -1029,14 +1036,13 @@ async fn create_backup(
>                  manifest.add_file(target, stats.size, stats.csum, crypto.mode)?;
>              }
>              (BackupSpecificationType::PXAR, false) => {
> -                let metadata_mode = false; // Until enabled via param
> -
>                  let target_base = if let Some(base) = target_base.strip_suffix(".pxar") {
>                      base.to_string()
>                  } else {
>                      bail!("unexpected suffix in target: {target_base}");
>                  };
>  
> +                let metadata_mode = detection_mode.is_metadata();
>                  let (target, payload_target) = if metadata_mode {
>                      (
>                          format!("{target_base}.mpxar.{extension}"),
> @@ -1061,12 +1067,51 @@ async fn create_backup(
>                      .unwrap()
>                      .start_directory(std::ffi::CString::new(target.as_str())?.as_c_str())?;
>  
> +                let mut previous_ref = None;
> +                if metadata_mode {
> +                    if let Some(ref manifest) = previous_manifest {

client.previous_backup_time() gives you the timestamp without the need
to query all snapshots, and it's guaranteed to match the
previous_manifest since both come from the same (lock-guarded) lookup
when starting the writer/backup H2 session.

> +                        let list = api_datastore_list_snapshots(
> +                            &http_client,
> +                            repo.store(),
> +                            &backup_ns,
> +                            Some(&snapshot.group),
> +                        )
> +                        .await?;
> +                        let mut list: Vec<SnapshotListItem> = serde_json::from_value(list)?;
> +
> +                        // BackupWriter::start created a new snapshot, get the one before
> +                        if list.len() > 1 {
> +                            list.sort_unstable_by(|a, b| b.backup.time.cmp(&a.backup.time));
> +                            let backup_dir: BackupDir =
> +                                (snapshot.group.clone(), list[1].backup.time).into();
> +                            let backup_reader = BackupReader::start(
> +                                &http_client,
> +                                crypt_config.clone(),
> +                                repo.store(),
> +                                &backup_ns,
> +                                &backup_dir,
> +                                true,
> +                            )
> +                            .await?;
> +                            previous_ref = prepare_reference(
> +                                &target,
> +                                manifest.clone(),
> +                                &client,
> +                                backup_reader.clone(),
> +                                crypt_config.clone(),
> +                            )
> +                            .await?
> +                        }
> +                    }
> +                }
> +
>                  let pxar_options = pbs_client::pxar::PxarCreateOptions {
>                      device_set: devices.clone(),
>                      patterns: pattern_list.clone(),
>                      entries_max: entries_max as usize,
>                      skip_lost_and_found,
>                      skip_e2big_xattr,
> +                    previous_ref,
>                  };
>  
>                  let upload_options = UploadOptions {
> diff --git a/proxmox-restore-daemon/src/proxmox_restore_daemon/api.rs b/proxmox-restore-daemon/src/proxmox_restore_daemon/api.rs
> index 0883d6cda..e50cb8184 100644
> --- a/proxmox-restore-daemon/src/proxmox_restore_daemon/api.rs
> +++ b/proxmox-restore-daemon/src/proxmox_restore_daemon/api.rs
> @@ -355,6 +355,7 @@ fn extract(
>                          patterns,
>                          skip_lost_and_found: false,
>                          skip_e2big_xattr: false,
> +                        previous_ref: None,
>                      };
>  
>                      let pxar_writer = TokioWriter::new(writer);
> diff --git a/pxar-bin/src/main.rs b/pxar-bin/src/main.rs
> index d46c98d2b..c6d3794bb 100644
> --- a/pxar-bin/src/main.rs
> +++ b/pxar-bin/src/main.rs
> @@ -358,6 +358,7 @@ async fn create_archive(
>          patterns,
>          skip_lost_and_found: false,
>          skip_e2big_xattr: false,
> +        previous_ref: None,
>      };
>  
>      let source = PathBuf::from(source);
> -- 
> 2.39.2
> 
> 
> 
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