Move snapshots/blockfile to plugins/snapshots/blockfile

Signed-off-by: Derek McGowan <derek@mcg.dev>

plugins/snapshots/blockfile/blockfile_loopsetup_test.go

@@ -0,0 +1,127 @@
+//go:build !windows && !darwin
+
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package blockfile
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"github.com/containerd/containerd/v2/core/mount"
+)
+
+func setupSnapshotter(t *testing.T) ([]Opt, error) {
+	mkfs, err := exec.LookPath("mkfs.ext4")
+	if err != nil {
+		t.Skipf("Could not find mkfs.ext4: %v", err)
+	}
+
+	loopbackSize := int64(8 << 20) // 8 MB
+	if os.Getpagesize() > 4096 {
+		loopbackSize = int64(16 << 20) // 16 MB
+	}
+
+	scratch := filepath.Join(t.TempDir(), "scratch")
+	scratchDevFile, err := os.OpenFile(scratch, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create %s: %w", scratch, err)
+	}
+
+	if err := scratchDevFile.Truncate(loopbackSize); err != nil {
+		scratchDevFile.Close()
+		return nil, fmt.Errorf("failed to resize %s file: %w", scratch, err)
+	}
+
+	if err := scratchDevFile.Sync(); err != nil {
+		scratchDevFile.Close()
+		return nil, fmt.Errorf("failed to sync %s file: %w", scratch, err)
+	}
+	scratchDevFile.Close()
+
+	if out, err := exec.Command(mkfs, scratch).CombinedOutput(); err != nil {
+		return nil, fmt.Errorf("failed to make ext4 filesystem (out: %q): %w", out, err)
+	}
+
+	defaultOpts := []string{"loop", "direct-io", "sync"}
+
+	if err := testMount(t, scratch, defaultOpts); err != nil {
+		return nil, err
+	}
+
+	return []Opt{
+		WithScratchFile(scratch),
+		WithFSType("ext4"),
+		WithMountOptions(defaultOpts),
+		WithRecreateScratch(false), // reduce IO presure in CI
+		withViewHookHelper(testViewHook),
+	}, nil
+}
+
+func testMount(t *testing.T, scratchFile string, opts []string) error {
+	root, err := os.MkdirTemp(t.TempDir(), "")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(root)
+
+	m := []mount.Mount{
+		{
+			Type:    "ext4",
+			Source:  scratchFile,
+			Options: opts,
+		},
+	}
+
+	if err := mount.All(m, root); err != nil {
+		return fmt.Errorf("failed to mount device %s: %w", scratchFile, err)
+	}
+
+	if err := os.Remove(filepath.Join(root, "lost+found")); err != nil {
+		return err
+	}
+	return mount.UnmountAll(root, 0)
+}
+
+func testViewHook(backingFile string, fsType string, defaultOpts []string) error {
+	root, err := os.MkdirTemp("", "blockfile-testViewHook-XXXX")
+	if err != nil {
+		return err
+	}
+	defer os.RemoveAll(root)
+
+	// FIXME(fuweid): Mount with rw to force fs to handle recover
+	mountOpts := []mount.Mount{
+		{
+			Type:    fsType,
+			Source:  backingFile,
+			Options: defaultOpts,
+		},
+	}
+
+	if err := mount.All(mountOpts, root); err != nil {
+		return fmt.Errorf("failed to mount device %s: %w", backingFile, err)
+	}
+
+	if err := mount.UnmountAll(root, 0); err != nil {
+		return fmt.Errorf("failed to unmount device %s: %w", backingFile, err)
+	}
+	return nil
+}