[pbs-devel] [PATCH proxmox-backup 1/5] server: pull: refactor snapshot pull logic

[Christian Ebner]

In preparation for skipping over snapshots when synchronizing with
encrypted/verified only flags set. In these cases, the manifest has
to be fetched from the remote and it's status checked. If the
snapshot should be skipped, the snapshot directory including the
temporary manifest file has to be cleaned up, given the snapshot
directory has been newly created. By reorganizing the current
snapshot pull logic, this can be achieved more easily.

The `corrupt` flag will be set to `false` in the snapshot
prefiltering, so the previous explicit distinction for newly created
snapshot directories must not be preserved.

No functional changes intended.

Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
---
 src/server/pull.rs | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/src/server/pull.rs b/src/server/pull.rs
index 516abfe5d..2c0ad9e1e 100644
--- a/src/server/pull.rs
+++ b/src/server/pull.rs
@@ -338,7 +338,16 @@ async fn pull_snapshot<'a>(
     snapshot: &'a pbs_datastore::BackupDir,
     downloaded_chunks: Arc<Mutex<HashSet<[u8; 32]>>>,
     corrupt: bool,
+    is_new: bool,
 ) -> Result<SyncStats, Error> {
+    if is_new {
+        info!("sync snapshot {}", snapshot.dir());
+    } else if corrupt {
+        info!("re-sync snapshot {} due to corruption", snapshot.dir());
+    } else {
+        info!("re-sync snapshot {}", snapshot.dir());
+    }
+
     let mut sync_stats = SyncStats::default();
     let mut manifest_name = snapshot.full_path();
     manifest_name.push(MANIFEST_BLOB_NAME.as_ref());
@@ -456,11 +465,11 @@ async fn pull_snapshot_from<'a>(
         .datastore()
         .create_locked_backup_dir(snapshot.backup_ns(), snapshot.as_ref())?;
 
-    let sync_stats = if is_new {
-        info!("sync snapshot {}", snapshot.dir());
+    let result = pull_snapshot(reader, snapshot, downloaded_chunks, corrupt, is_new).await;
 
-        // this snapshot is new, so it can never be corrupt
-        match pull_snapshot(reader, snapshot, downloaded_chunks, false).await {
+    if is_new {
+        // Cleanup directory on error if snapshot was not present before
+        match result {
             Err(err) => {
                 if let Err(cleanup_err) = snapshot.datastore().remove_backup_dir(
                     snapshot.backup_ns(),
@@ -471,21 +480,11 @@ async fn pull_snapshot_from<'a>(
                 }
                 return Err(err);
             }
-            Ok(sync_stats) => {
-                info!("sync snapshot {} done", snapshot.dir());
-                sync_stats
-            }
+            Ok(_) => info!("sync snapshot {} done", snapshot.dir()),
         }
-    } else {
-        if corrupt {
-            info!("re-sync snapshot {} due to corruption", snapshot.dir());
-        } else {
-            info!("re-sync snapshot {}", snapshot.dir());
-        }
-        pull_snapshot(reader, snapshot, downloaded_chunks, corrupt).await?
-    };
+    }
 
-    Ok(sync_stats)
+    result
 }
 
 /// Pulls a group according to `params`.
-- 
2.39.5