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Add the parent directory to changes set if new files are generated

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The "TestChangesWithChanges" case randomlly fails on my development
VM with the following errors:
```
--- FAIL: TestChangesWithChanges (0.00s)
        changes_test.go:201: no change for expected change C /dir1/subfolder != A /dir1/subfolder/newFile
```

If I apply the following patch to changes_test.go, the test passes.

```diff
diff --git a/pkg/archive/changes_test.go b/pkg/archive/changes_test.go
index 290b2dd..ba1aca0 100644
--- a/pkg/archive/changes_test.go
+++ b/pkg/archive/changes_test.go
@@ -156,6 +156,7 @@ func TestChangesWithChanges(t *testing.T) {
        }
        defer os.RemoveAll(layer)
        createSampleDir(t, layer)
+       time.Sleep(5 * time.Millisecond)
        os.MkdirAll(path.Join(layer, "dir1/subfolder"), 0740)

        // Let's modify modtime for dir1 to be sure it's the same for the two layer (to not having false positive)
```

It seems that if a file is created immediately after the directory is created,
the `archive.Changes` function could't recognize that the parent directory of
the new file is modified.

Perhaps the problem may reproduce on machines with low time precision?
I had successfully reproduced the failure on my development VM as well as
a VM on DigitalOcean.

Signed-off-by: Shijiang Wei <mountkin@gmail.com>
This commit is contained in:
Shijiang Wei 2015-05-29 16:39:14 +08:00
parent 6c2626b90e
commit e10c7b3f07
2 changed files with 110 additions and 41 deletions
Download patch file Download diff file Expand all files Collapse all files

21
archive/changes.go
View file

@ -68,7 +68,11 @@ func sameFsTimeSpec(a, b syscall.Timespec) bool {
// Changes walks the path rw and determines changes for the files in the path,
// with respect to the parent layers
func Changes(layers []string, rw string) ([]Change, error) {
var changes []Change
var (
changes []Change
changedDirs = make(map[string]struct{})
)
err := filepath.Walk(rw, func(path string, f os.FileInfo, err error) error {
if err != nil {
return err
@ -129,6 +133,21 @@ func Changes(layers []string, rw string) ([]Change, error) {
}
}
// If /foo/bar/file.txt is modified, then /foo/bar must be part of the changed files.
// This block is here to ensure the change is recorded even if the
// modify time, mode and size of the parent directoriy in the rw and ro layers are all equal.
// Check https://github.com/docker/docker/pull/13590 for details.
if f.IsDir() {
changedDirs[path] = struct{}{}
}
if change.Kind == ChangeAdd || change.Kind == ChangeDelete {
parent := filepath.Dir(path)
if _, ok := changedDirs[parent]; !ok && parent != "/" {
changes = append(changes, Change{Path: parent, Kind: ChangeModify})
changedDirs[parent] = struct{}{}
}
}
// Record change
changes = append(changes, change)
return nil