From 9175795fdbacea2cf882d30357217194c60a7a47 Mon Sep 17 00:00:00 2001
From: Alexander Weiss <alex@weissfam.de>
Date: Thu, 9 Jul 2020 22:35:04 +0200
Subject: [PATCH] Check contents in archiver
When backing up with a parent snapshot and the file is not changed, also
check if contents are still available in index.
---
changelog/unreleased/issue-2571 | 16 +++++++++++
cmd/restic/integration_test.go | 47 +++++++++++++++++++++++++++++++++
internal/archiver/archiver.go | 43 +++++++++++++++++++++---------
3 files changed, 94 insertions(+), 12 deletions(-)
create mode 100644 changelog/unreleased/issue-2571
diff --git a/changelog/unreleased/issue-2571 b/changelog/unreleased/issue-2571
new file mode 100644
index 000000000..64fcc3160
--- /dev/null
+++ b/changelog/unreleased/issue-2571
@@ -0,0 +1,16 @@
+Enhancement: Self-heal missing file parts during backup of unchanged files
+
+We've improved the resilience of restic to certain types of repository corruption.
+
+For files that are unchanged since the parent snapshot, the backup command now
+verifies that all parts of the files still exist in the repository. Parts that are
+missing, e.g. from a damaged repository, are backed up again. This verification
+was already run for files that were modified since the parent snapshot, but is
+now also done for unchanged files.
+
+Note that restic will not backup file parts that are referenced in the index but
+where the actual data is not present on disk, as this situation can only be
+detected by restic check. Please ensure that you run `restic check` regularly.
+
+https://github.com/restic/restic/issues/2571
+https://github.com/restic/restic/pull/2827
diff --git a/cmd/restic/integration_test.go b/cmd/restic/integration_test.go
index b94e50520..5ffb5ee22 100644
--- a/cmd/restic/integration_test.go
+++ b/cmd/restic/integration_test.go
@@ -359,6 +359,53 @@ func TestBackupNonExistingFile(t *testing.T) {
testRunBackup(t, "", dirs, opts, env.gopts)
}
+func TestBackupSelfHealing(t *testing.T) {
+ env, cleanup := withTestEnvironment(t)
+ defer cleanup()
+
+ testRunInit(t, env.gopts)
+
+ p := filepath.Join(env.testdata, "test/test")
+ rtest.OK(t, os.MkdirAll(filepath.Dir(p), 0755))
+ rtest.OK(t, appendRandomData(p, 5))
+
+ opts := BackupOptions{}
+
+ testRunBackup(t, filepath.Dir(env.testdata), []string{filepath.Base(env.testdata)}, opts, env.gopts)
+ testRunCheck(t, env.gopts)
+
+ r, err := OpenRepository(env.gopts)
+ rtest.OK(t, err)
+
+ // Get all tree packs
+ rtest.OK(t, r.LoadIndex(env.gopts.ctx))
+ treePacks := restic.NewIDSet()
+ for _, idx := range r.Index().(*repository.MasterIndex).All() {
+ for _, id := range idx.TreePacks() {
+ treePacks.Insert(id)
+ }
+ }
+
+ // remove all data packs
+ rtest.OK(t, r.List(env.gopts.ctx, restic.DataFile, func(id restic.ID, size int64) error {
+ if treePacks.Has(id) {
+ return nil
+ }
+ return r.Backend().Remove(env.gopts.ctx, restic.Handle{Type: restic.DataFile, Name: id.String()})
+ }))
+
+ testRunRebuildIndex(t, env.gopts)
+ // now the repo is also missing the data blob in the index; check should report this
+ rtest.Assert(t, runCheck(CheckOptions{}, env.gopts, nil) != nil,
+ "check should have reported an error")
+
+ // second backup should report an error but "heal" this situation
+ err = testRunBackupAssumeFailure(t, filepath.Dir(env.testdata), []string{filepath.Base(env.testdata)}, opts, env.gopts)
+ rtest.Assert(t, err != nil,
+ "backup should have reported an error")
+ testRunCheck(t, env.gopts)
+}
+
func includes(haystack []string, needle string) bool {
for _, s := range haystack {
if s == needle {
diff --git a/internal/archiver/archiver.go b/internal/archiver/archiver.go
index bc1432c28..51ec94f15 100644
--- a/internal/archiver/archiver.go
+++ b/internal/archiver/archiver.go
@@ -302,6 +302,18 @@ func (fn *FutureNode) wait(ctx context.Context) {
}
}
+// allBlobsPresent checks if all blobs (contents) of the given node are
+// present in the index.
+func (arch *Archiver) allBlobsPresent(previous *restic.Node) bool {
+ // check if all blobs are contained in index
+ for _, id := range previous.Content {
+ if !arch.Repo.Index().Has(id, restic.DataBlob) {
+ return false
+ }
+ }
+ return true
+}
+
// Save saves a target (file or directory) to the repo. If the item is
// excluded, this function returns a nil node and error, with excluded set to
// true.
@@ -388,19 +400,26 @@ func (arch *Archiver) Save(ctx context.Context, snPath, target string, previous
// use previous list of blobs if the file hasn't changed
if previous != nil && !fileChanged(fi, previous, arch.IgnoreInode) {
- debug.Log("%v hasn't changed, using old list of blobs", target)
- arch.CompleteItem(snPath, previous, previous, ItemStats{}, time.Since(start))
- arch.CompleteBlob(snPath, previous.Size)
- fn.node, err = arch.nodeFromFileInfo(target, fi)
- if err != nil {
- return FutureNode{}, false, err
+ if arch.allBlobsPresent(previous) {
+ debug.Log("%v hasn't changed, using old list of blobs", target)
+ arch.CompleteItem(snPath, previous, previous, ItemStats{}, time.Since(start))
+ arch.CompleteBlob(snPath, previous.Size)
+ fn.node, err = arch.nodeFromFileInfo(target, fi)
+ if err != nil {
+ return FutureNode{}, false, err
+ }
+
+ // copy list of blobs
+ fn.node.Content = previous.Content
+
+ _ = file.Close()
+ return fn, false, nil
+ } else {
+ debug.Log("%v hasn't changed, but contents are missing!", target)
+ // There are contents missing - inform user!
+ err := errors.Errorf("parts of %v not found in the repository index; storing the file again", target)
+ arch.error(abstarget, fi, err)
}
-
- // copy list of blobs
- fn.node.Content = previous.Content
-
- _ = file.Close()
- return fn, false, nil
}
fn.isFile = true