Block cim create and mount check update

internal/wclayer/cim/cim_writer_test.go

@@ -11,7 +11,7 @@ import (
 )
 
 func TestSingleFileWriterTypeMismatch(t *testing.T) {
-	if !cimfs.IsBlockCimSupported() {
+	if !cimfs.IsBlockCimWriteSupported() {
 		t.Skipf("BlockCIM not supported")
 	}
 
@@ -34,7 +34,7 @@ func TestSingleFileWriterTypeMismatch(t *testing.T) {
 }
 
 func TestSingleFileWriterInvalidBlockType(t *testing.T) {
-	if !cimfs.IsBlockCimSupported() {
+	if !cimfs.IsBlockCimWriteSupported() {
 		t.Skipf("BlockCIM not supported")
 	}
 

internal/winapi/utils.go

@@ -8,8 +8,6 @@ import (
 	"unsafe"
 
 	"golang.org/x/sys/windows"
-
-	"github.com/Microsoft/hcsshim/internal/winapi/cimfs"
 )
 
 // Uint16BufferToSlice wraps a uint16 pointer-and-length into a slice
@@ -83,8 +81,3 @@ func ConvertStringSetToSlice(buf []byte) ([]string, error) {
 func ParseUtf16LE(b []byte) string {
 	return windows.UTF16PtrToString((*uint16)(unsafe.Pointer(&b[0])))
 }
-
-// CimFsSupported checks if either CIMFS dll is present on the system.
-func CimFsSupported() bool {
-	return cimfs.Supported()
-}

pkg/cimfs/cim_test.go

@@ -226,7 +226,7 @@ func TestCimReadWrite(t *testing.T) {
 }
 
 func TestBlockCIMInvalidCimName(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimWriteSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -239,7 +239,7 @@ func TestBlockCIMInvalidCimName(t *testing.T) {
 }
 
 func TestBlockCIMInvalidBlockPath(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimWriteSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -252,7 +252,7 @@ func TestBlockCIMInvalidBlockPath(t *testing.T) {
 }
 
 func TestBlockCIMInvalidType(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimWriteSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -265,7 +265,7 @@ func TestBlockCIMInvalidType(t *testing.T) {
 }
 
 func TestCIMMergeInvalidType(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimMountSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -282,7 +282,7 @@ func TestCIMMergeInvalidType(t *testing.T) {
 }
 
 func TestCIMMergeInvalidSourceType(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimMountSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -313,7 +313,7 @@ func TestCIMMergeInvalidSourceType(t *testing.T) {
 }
 
 func TestCIMMergeInvalidLength(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimMountSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -329,7 +329,7 @@ func TestCIMMergeInvalidLength(t *testing.T) {
 }
 
 func TestBlockCIMEmpty(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimWriteSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -347,7 +347,7 @@ func TestBlockCIMEmpty(t *testing.T) {
 }
 
 func TestBlockCIMSingleFileReadWrite(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimMountSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -411,7 +411,7 @@ func createBlockDevice(t *testing.T, dir string) string {
 }
 
 func TestBlockCIMBlockDeviceReadWrite(t *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimMountSupported() {
 		t.Skip("blockCIM not supported on this OS version")
 	}
 
@@ -440,7 +440,7 @@ func TestBlockCIMBlockDeviceReadWrite(t *testing.T) {
 }
 
 func TestMergedBlockCIMs(rootT *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimMountSupported() {
 		rootT.Skipf("BlockCIM not supported")
 	}
 
@@ -534,7 +534,7 @@ func TestMergedBlockCIMs(rootT *testing.T) {
 }
 
 func TestTombstoneInMergedBlockCIMs(rootT *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimMountSupported() {
 		rootT.Skipf("BlockCIM not supported")
 	}
 
@@ -608,7 +608,7 @@ func TestTombstoneInMergedBlockCIMs(rootT *testing.T) {
 }
 
 func TestMergedLinksInMergedBlockCIMs(rootT *testing.T) {
-	if !IsBlockCimSupported() {
+	if !IsBlockCimMountSupported() {
 		rootT.Skipf("BlockCIM not supported")
 	}
 
@@ -688,7 +688,7 @@ func TestMergedLinksInMergedBlockCIMs(rootT *testing.T) {
 }
 
 func TestVerifiedSingleFileBlockCIMMount(t *testing.T) {
-	if !IsVerifiedCimSupported() {
+	if !IsVerifiedCimMountSupported() {
 		t.Skipf("verified CIMs are not supported")
 	}
 
@@ -733,7 +733,7 @@ func TestVerifiedSingleFileBlockCIMMount(t *testing.T) {
 }
 
 func TestVerifiedSingleFileBlockCIMMountReadFailure(t *testing.T) {
-	if !IsVerifiedCimSupported() {
+	if !IsVerifiedCimMountSupported() {
 		t.Skipf("verified CIMs are not supported")
 	}
 
@@ -777,7 +777,11 @@ func TestVerifiedSingleFileBlockCIMMountReadFailure(t *testing.T) {
 }
 
 func TestMergedVerifiedBlockCIMs(rootT *testing.T) {
-	if !IsVerifiedCimSupported() {
+	if !IsVerifiedCimWriteSupported() {
+		rootT.Skipf("verified BlockCIMs are not supported")
+	}
+
+	if !IsVerifiedCimMountSupported() {
 		rootT.Skipf("verified BlockCIMs are not supported")
 	}
 

pkg/cimfs/cim_writer_windows.go

@@ -118,11 +118,11 @@ func CreateBlockCIMWithOptions(ctx context.Context, bCIM *BlockCIM, options ...B
 	}
 
 	// Check OS support
-	if !IsBlockCimSupported() {
+	if !IsBlockCimWriteSupported() {
 		return nil, fmt.Errorf("block CIM not supported on this OS version")
 	}
 
-	if config.dataIntegrity && !IsVerifiedCimSupported() {
+	if config.dataIntegrity && !IsVerifiedCimWriteSupported() {
 		return nil, fmt.Errorf("verified CIMs are not supported on this OS version")
 	}
 
@@ -436,7 +436,7 @@ func GetCimUsage(ctx context.Context, cimPath string) (uint64, error) {
 // files with the same path at all other CIMs) When mounting this merged CIM the source
 // CIMs MUST be provided in the exact same order.
 func MergeBlockCIMsWithOpts(ctx context.Context, mergedCIM *BlockCIM, sourceCIMs []*BlockCIM, opts ...BlockCIMOpt) (err error) {
-	if !IsMergedCimSupported() {
+	if !IsMergedCimWriteSupported() {
 		return fmt.Errorf("merged CIMs aren't supported on this OS version")
 	} else if len(sourceCIMs) < 2 {
 		return fmt.Errorf("need at least 2 source CIMs, got %d: %w", len(sourceCIMs), os.ErrInvalid)

pkg/cimfs/cimfs.go

@@ -4,7 +4,9 @@
 package cimfs
 
 import (
-	"github.com/Microsoft/hcsshim/internal/winapi"
+	"github.com/Microsoft/hcsshim/internal/winapi/cimfs"
+	"github.com/Microsoft/hcsshim/internal/winapi/cimwriter"
+
 	"path/filepath"
 
 	"github.com/Microsoft/hcsshim/osversion"
@@ -19,7 +21,7 @@ func IsCimFSSupported() bool {
 	build := osversion.Build()
 	// CimFS support is backported to LTSC2022 starting with revision 2031 and should
 	// otherwise be available on all builds >= V25H1Server
-	return (build >= osversion.V25H1Server || (build == osversion.V21H2Server && rv >= 2031)) && winapi.CimFsSupported()
+	return (build >= osversion.V25H1Server || (build == osversion.V21H2Server && rv >= 2031)) && cimfs.Supported()
 }
 
 // IsBlockCimSupported returns true if block formatted CIMs (i.e block device CIM &
@@ -29,7 +31,27 @@ func IsBlockCimSupported() bool {
 	// TODO(ambarve): Currently we are checking against a higher build number since there is no
 	// official build with block CIM support yet. Once we have that build, we should
 	// update the build number here.
-	return build >= 27766 && winapi.CimFsSupported()
+	return build >= 27766 && cimfs.Supported()
+}
+
+// IsBlockCimWriteSupported returns true if block formatted CIMs (i.e block device CIM &
+// single file CIM) are supported on the current OS build or if CimWriter is present.
+func IsBlockCimWriteSupported() bool {
+	build := osversion.Build()
+	// TODO(ambarve): Currently we are checking against a higher build number since there is no
+	// official build with block CIM support yet. Once we have that build, we should
+	// update the build number here.
+	return (build >= 27766 && cimfs.Supported()) || cimwriter.Supported()
+}
+
+// IsBlockCimMountSupported returns true if block formatted CIMs (i.e block device CIM &
+// single file CIM) are supported on the current OS build.
+func IsBlockCimMountSupported() bool {
+	build := osversion.Build()
+	// TODO(ambarve): Currently we are checking against a higher build number since there is no
+	// official build with block CIM support yet. Once we have that build, we should
+	// update the build number here.
+	return build >= 27766 && cimfs.Supported()
 }
 
 // IsVerifiedCimSupported returns true if block CIM format supports also writing verification information in the CIM.
@@ -38,7 +60,25 @@ func IsVerifiedCimSupported() bool {
 	// TODO(ambarve): Currently we are checking against a higher build number since there is no
 	// official build with block CIM support yet. Once we have that build, we should
 	// update the build number here.
-	return build >= 27800 && winapi.CimFsSupported()
+	return build >= 27800 && cimfs.Supported()
+}
+
+// IsVerifiedCimWriteSupported returns true if block CIM format supports also writing verification information in the CIM.
+func IsVerifiedCimWriteSupported() bool {
+	build := osversion.Build()
+	// TODO(ambarve): Currently we are checking against a higher build number since there is no
+	// official build with block CIM support yet. Once we have that build, we should
+	// update the build number here.
+	return (build >= 27800 && cimfs.Supported()) || cimwriter.Supported()
+}
+
+// IsVerifiedCimMountSupported returns true if block CIM format supports mounting.
+func IsVerifiedCimMountSupported() bool {
+	build := osversion.Build()
+	// TODO(ambarve): Currently we are checking against a higher build number since there is no
+	// official build with block CIM support yet. Once we have that build, we should
+	// update the build number here.
+	return build >= 27800 && cimfs.Supported()
 }
 
 func IsMergedCimSupported() bool {
@@ -48,6 +88,20 @@ func IsMergedCimSupported() bool {
 	return IsBlockCimSupported()
 }
 
+func IsMergedCimWriteSupported() bool {
+	// The merged CIM support was originally added before block CIM support.  However,
+	// some of the merged CIM features that we use (e.g. merged hard links) were added
+	// later along with block CIM support. So use the same check as block CIM here.
+	return IsBlockCimWriteSupported()
+}
+
+func IsMergedCimMountSupported() bool {
+	// The merged CIM support was originally added before block CIM support.  However,
+	// some of the merged CIM features that we use (e.g. merged hard links) were added
+	// later along with block CIM support. So use the same check as block CIM here.
+	return IsBlockCimMountSupported()
+}
+
 type BlockCIMType uint32
 
 const (

pkg/cimfs/mount_cim.go

@@ -75,7 +75,7 @@ func Unmount(volumePath string) error {
 // `MergeBlockCIMs`) at a volume with given GUID. The `sourceCIMs` MUST be identical
 // to the `sourceCIMs` passed to `MergeBlockCIMs` when creating this merged CIM.
 func MountMergedBlockCIMs(mergedCIM *BlockCIM, sourceCIMs []*BlockCIM, mountFlags uint32, volumeGUID guid.GUID) (string, error) {
-	if !IsMergedCimSupported() {
+	if !IsMergedCimMountSupported() {
 		return "", fmt.Errorf("merged CIMs aren't supported on this OS version")
 	} else if len(sourceCIMs) < 2 {
 		return "", fmt.Errorf("need at least 2 source CIMs, got %d: %w", len(sourceCIMs), os.ErrInvalid)
@@ -162,7 +162,7 @@ func MountVerifiedBlockCIM(bCIM *BlockCIM, mountFlags uint32, volumeGUID guid.GU
 // to match against the provided root hash if it doesn't, the read will fail.  The source
 // CIMs and the merged CIM MUST have been created with the verified creation flag.
 func MountMergedVerifiedBlockCIMs(mergedCIM *BlockCIM, sourceCIMs []*BlockCIM, mountFlags uint32, volumeGUID guid.GUID, rootHash []byte) (string, error) {
-	if !IsVerifiedCimSupported() {
+	if !IsVerifiedCimMountSupported() {
 		return "", fmt.Errorf("verified CIMs aren't supported on this OS version")
 	} else if len(sourceCIMs) < 2 {
 		return "", fmt.Errorf("need at least 2 source CIMs, got %d: %w", len(sourceCIMs), os.ErrInvalid)

pkg/extractuvm/bcim_test.go

@@ -153,7 +153,7 @@ func extractAndVerifyTarToCIM(t *testing.T, tarContents []testFile, contentsToVe
 }
 
 func TestTarUtilityVMExtract(t *testing.T) {
-	if !cimfs.IsVerifiedCimSupported() {
+	if !cimfs.IsVerifiedCimMountSupported() {
 		t.Skip("block CIMs are not supported on this build")
 	}
 

test/functional/make_uvm_cim_test.go

@@ -192,7 +192,7 @@ func mountBlockCIM(t *testing.T, bCIM *cimfs.BlockCIM, mountFlags uint32) string
 
 // TestCompareUtilityVMCIM compares generated UtilityVM CIM's contents against the WCIFS based layer and ensures that they match.
 func TestCompareUtilityVMCIM(t *testing.T) {
-	if !cimfs.IsBlockCimSupported() {
+	if !cimfs.IsBlockCimMountSupported() {
 		t.Skip("block CIMs are not supported on this build")
 	}