fix: btrfs destinations could not use btfs sources when reuse-snapsho…

…ts was enabled
sloonz · Dec 19, 2024 · d48e3ad · d48e3ad
1 parent 1e1b406
commit d48e3ad
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Showing 2 changed files with 19 additions and 8 deletions.
diff --git a/sources/btrfs.go b/sources/btrfs.go
@@ -114,6 +114,7 @@ func (s *btrfsSource) RemoveSnapshot(snapshot uback.Snapshot) error {
 
 // Part of uback.Source interface
 func (s *btrfsSource) CreateBackup(baseSnapshot *uback.Snapshot) (uback.Backup, io.ReadCloser, error) {
+	reused := false
 	snapshot := time.Now().UTC().Format(uback.SnapshotTimeFormat)
 	finalSnapshotPath := path.Join(s.snapshotsPath, snapshot)
 	tmpSnapshotPath := path.Join(s.snapshotsPath, fmt.Sprintf("_tmp-%s", snapshot))
@@ -131,9 +132,10 @@ func (s *btrfsSource) CreateBackup(baseSnapshot *uback.Snapshot) (uback.Backup,
 			}
 
 			if time.Now().UTC().Sub(t).Seconds() <= float64(s.reuseSnapshots) {
+				reused = true
 				snapshot = string(snapshots[0])
 				finalSnapshotPath = path.Join(s.snapshotsPath, snapshot)
-				tmpSnapshotPath = finalSnapshotPath
+				tmpSnapshotPath = path.Join(s.snapshotsPath, fmt.Sprintf("_tmp-%s", snapshot))
 			}
 		}
 	}
@@ -143,14 +145,18 @@ func (s *btrfsSource) CreateBackup(baseSnapshot *uback.Snapshot) (uback.Backup,
 	}
 
 	backup := uback.Backup{Snapshot: uback.Snapshot(snapshot), BaseSnapshot: baseSnapshot}
-	if tmpSnapshotPath != finalSnapshotPath {
+	if reused {
+		err := uback.RunCommand(btrfsLog, uback.BuildCommand(s.snapshotCommand, "-r", finalSnapshotPath, tmpSnapshotPath))
+		if err != nil {
+			return uback.Backup{}, nil, err
+		}
+		btrfsLog.Printf("reusing backup: %s", backup.Filename())
+	} else {
 		err := uback.RunCommand(btrfsLog, uback.BuildCommand(s.snapshotCommand, "-r", s.basePath, tmpSnapshotPath))
 		if err != nil {
 			return uback.Backup{}, nil, err
 		}
 		btrfsLog.Printf("creating backup: %s", backup.Filename())
-	} else {
-		btrfsLog.Printf("reusing backup: %s", backup.Filename())
 	}
 
 	args := []string{}
@@ -163,10 +169,12 @@ func (s *btrfsSource) CreateBackup(baseSnapshot *uback.Snapshot) (uback.Backup,
 			_ = uback.RunCommand(btrfsLog, uback.BuildCommand(s.deleteCommand, tmpSnapshotPath))
 			return err
 		}
-		if tmpSnapshotPath != finalSnapshotPath {
+		if reused {
+			cmd := uback.BuildCommand(s.deleteCommand, tmpSnapshotPath)
+			return uback.RunCommand(btrfsLog, cmd)
+		} else {
 			return os.Rename(tmpSnapshotPath, finalSnapshotPath)
 		}
-		return nil
 	})
 }
 

diff --git a/tests/src_btrfs_tests.py b/tests/src_btrfs_tests.py
@@ -43,9 +43,9 @@ def test_btrfs_source(self):
         self._test_src(self.tmpdir, source, dest, "receive-command=sudo btrfs receive", test_ignore=False, test_delete=True)
 
     def test_btrfs_reuse_snapshots(self):
-        source = f"type=btrfs,path={self.tmpdir}/source,key-file={self.tmpdir}/backup.pub,state-file={self.tmpdir}/state.json,snapshots-path={self.tmpdir}/snapshots,full-interval=weekly," +\
+        source = f"type=btrfs,path={self.tmpdir}/source,no-encryption=1,state-file={self.tmpdir}/state.json,snapshots-path={self.tmpdir}/snapshots,full-interval=weekly," +\
             "send-command=sudo btrfs send,delete-command=sudo btrfs subvolume delete,reuse-snapshots=1d"
-        dest = f"type=fs,@retention-policy=daily=3,key-file={self.tmpdir}/backup.key"
+        dest = f"type=btrfs,@retention-policy=daily=3"
 
         ensure_dir(f"{self.tmpdir}/backups1")
         ensure_dir(f"{self.tmpdir}/backups2")
@@ -62,3 +62,6 @@ def test_btrfs_reuse_snapshots(self):
         self.assertEqual(set(os.listdir(f"{self.tmpdir}/snapshots")), {s})
         with open(f"{self.tmpdir}/state.json") as fd:
             self.assertEqual(json.load(fd), {"test1": s, "test2": s})
+
+        subprocess.check_call(["sudo", "btrfs", "subvolume", "delete", f"{self.tmpdir}/backups1/{s}"])
+        subprocess.check_call(["sudo", "btrfs", "subvolume", "delete", f"{self.tmpdir}/backups2/{s}"])