cmount: make work under OpenBSD - fixes #1727

cmd/cmount/fs.go

@@ -1,4 +1,4 @@
-//go:build cmount && ((linux && cgo) || (darwin && cgo) || (freebsd && cgo) || windows)
+//go:build cmount && ((linux && cgo) || (darwin && cgo) || (freebsd && cgo) || (openbsd && cgo) || windows)
 
 package cmount
 
@@ -6,6 +6,7 @@ import (
 	"io"
 	"os"
 	"path"
+	"runtime"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -210,6 +211,12 @@ func (fsys *FS) Readdir(dirPath string,
 	// We can't seek in directories and FUSE should know that so
 	// return an error if ofst is ever set.
 	if ofst > 0 {
+		// However openbsd doesn't seem to know this - perhaps a bug in its
+		// FUSE implementation or a bug in cgofuse?
+		// See: https://github.com/billziss-gh/cgofuse/issues/49
+		if runtime.GOOS == "openbsd" {
+			return 0
+		}
 		return -fuse.ESPIPE
 	}
 

cmd/cmount/mount.go

@@ -1,4 +1,4 @@
-//go:build cmount && ((linux && cgo) || (darwin && cgo) || (freebsd && cgo) || windows)
+//go:build cmount && ((linux && cgo) || (darwin && cgo) || (freebsd && cgo) || (openbsd && cgo) || windows)
 
 // Package cmount implements a FUSE mounting system for rclone remotes.
 //
@@ -8,9 +8,9 @@ package cmount
 import (
 	"errors"
 	"fmt"
-	"strings"
 	"os"
 	"runtime"
+	"strings"
 	"time"
 
 	"github.com/rclone/rclone/cmd/mountlib"
@@ -59,12 +59,14 @@ func mountOptions(VFS *vfs.VFS, device string, mountpoint string, opt *mountlib.
 	} else {
 		options = append(options, "-o", "fsname="+device)
 		options = append(options, "-o", "subtype=rclone")
+		if runtime.GOOS != "openbsd" {
 			options = append(options, "-o", fmt.Sprintf("max_readahead=%d", opt.MaxReadAhead))
 			// This causes FUSE to supply O_TRUNC with the Open
 			// call which is more efficient for cmount.  However
 			// it does not work with cgofuse on Windows with
 			// WinFSP so cmount must work with or without it.
 			options = append(options, "-o", "atomic_o_trunc")
+		}
 		if opt.DaemonTimeout != 0 {
 			options = append(options, "-o", fmt.Sprintf("daemon_timeout=%d", int(time.Duration(opt.DaemonTimeout).Seconds())))
 		}

cmd/cmount/mount_test.go

@@ -1,4 +1,4 @@
-//go:build cmount && ((linux && cgo) || (darwin && cgo) || (freebsd && cgo) || windows) && (!race || !windows)
+//go:build cmount && ((linux && cgo) || (darwin && cgo) || (freebsd && cgo) || (openbsd && cgo) || windows) && (!race || !windows)
 
 // Package cmount implements a FUSE mounting system for rclone remotes.
 //

cmd/cmount/mount_unsupported.go

@@ -1,4 +1,4 @@
-//go:build !((linux && cgo && cmount) || (darwin && cgo && cmount) || (freebsd && cgo && cmount) || (windows && cmount))
+//go:build !((linux && cgo && cmount) || (darwin && cgo && cmount) || (freebsd && cgo && cmount) || (openbsd && cgo && cmount) || (windows && cmount))
 
 // Package cmount implements a FUSE mounting system for rclone remotes.
 //