feat: Propagate O_DIRECT flag in OpenFileOp and CreateFileOp

conversions.go

@@ -245,6 +245,7 @@ func convertInMessage(
 				Pid:    inMsg.Header().Pid,
 				Uid:    inMsg.Header().Uid,
 			},
+			OpenFlags: fusekernel.OpenFlags(in.Flags),
 		}
 
 	case fusekernel.OpSymlink:

fuseops/ops.go

@@ -356,6 +356,10 @@ type CreateFileOp struct {
 	// later call to ReleaseFileHandle.
 	Handle    HandleID
 	OpContext OpContext
+
+	// The flags from the open(2) call, passed through the kernel's fuse driver
+	// to the FUSE daemon.
+	OpenFlags fusekernel.OpenFlags
 }
 
 // Create a symlink inode. If the name already exists, the file system should
@@ -681,6 +685,8 @@ type OpenFileOp struct {
 	// advance, for example, because contents are generated on the fly.
 	UseDirectIO bool
 
+	// The flags from the open(2) call, passed through the kernel's fuse driver
+	// to the FUSE daemon.
 	OpenFlags fusekernel.OpenFlags
 
 	OpContext OpContext

internal/fusekernel/fuse_kernel_darwin.go

@@ -59,10 +59,6 @@ func (in *SetattrIn) Flags() uint32 {
 	return in.Flags_
 }
 
-func openFlags(flags uint32) OpenFlags {
-	return OpenFlags(flags)
-}
-
 type GetxattrIn struct {
 	getxattrInCommon
 

internal/fusekernel/fuse_kernel_linux.go

@@ -1,6 +1,9 @@
 package fusekernel
 
-import "time"
+import (
+	"syscall"
+	"time"
+)
 
 type Attr struct {
 	Ino       uint64
@@ -49,16 +52,18 @@ func (in *SetattrIn) Flags() uint32 {
 	return 0
 }
 
-func openFlags(flags uint32) OpenFlags {
-	// on amd64, the 32-bit O_LARGEFILE flag is always seen;
-	// on i386, the flag probably depends on the app
-	// requesting, but in any case should be utterly
-	// uninteresting to us here; our kernel protocol messages
-	// are not directly related to the client app's kernel
-	// API/ABI
-	flags &^= 0x8000
+const OpenDirect OpenFlags = syscall.O_DIRECT
 
-	return OpenFlags(flags)
+// Return true if OpenDirect is set.
+func (fl OpenFlags) IsDirect() bool {
+	return fl&OpenDirect != 0
+}
+
+func init() {
+	openFlagNames = append(openFlagNames, flagName{
+		bit:  uint32(OpenDirect),
+		name: "OpenDirect",
+	})
 }
 
 type GetxattrIn struct {