@@ -116,19 +116,6 @@ func parseOptions(opt []string) (ZfsOptions, error) {

 	return options, nil

 }

-func checkRootdirFs(rootdir string) error {

-	var buf syscall.Statfs_t

-	if err := syscall.Statfs(rootdir, &buf); err != nil {

-		return fmt.Errorf("Failed to access '%s': %s", rootdir, err)

-	}

-

-	if graphdriver.FsMagic(buf.Type) != graphdriver.FsMagicZfs {

-		log.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)

-		return graphdriver.ErrPrerequisites

-	}

-	return nil

-}

-

 func lookupZfsDataset(rootdir string) (string, error) {

 	var stat syscall.Stat_t

 	if err := syscall.Stat(rootdir, &stat); err != nil {

new file mode 100644

@@ -0,0 +1,24 @@

+package zfs

+

+import (

+	"fmt"

+	"syscall"

+

+	log "github.com/Sirupsen/logrus"

+	"github.com/docker/docker/daemon/graphdriver"

+)

+

+func checkRootdirFs(rootdir string) error {

+	var buf syscall.Statfs_t

+	if err := syscall.Statfs(rootdir, &buf); err != nil {

+		return fmt.Errorf("Failed to access '%s': %s", rootdir, err)

+	}

+

+	// on FreeBSD buf.Fstypename contains ['z', 'f', 's', 0 ... ]

+	if (buf.Fstypename[0] != 122) || (buf.Fstypename[1] != 102) || (buf.Fstypename[2] != 115) || (buf.Fstypename[3] != 0) {

+		log.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)

+		return graphdriver.ErrPrerequisites

+	}

+

+	return nil

+}

new file mode 100644

@@ -0,0 +1,23 @@

+package zfs

+

+import (

+	"fmt"

+	"syscall"

+

+	log "github.com/Sirupsen/logrus"

+	"github.com/docker/docker/daemon/graphdriver"

+)

+

+func checkRootdirFs(rootdir string) error {

+	var buf syscall.Statfs_t

+	if err := syscall.Statfs(rootdir, &buf); err != nil {

+		return fmt.Errorf("Failed to access '%s': %s", rootdir, err)

+	}

+

+	if graphdriver.FsMagic(buf.Type) != graphdriver.FsMagicZfs {

+		log.Debugf("[zfs] no zfs dataset found for rootdir '%s'", rootdir)

+		return graphdriver.ErrPrerequisites

+	}

+

+	return nil

+}

@@ -1,3 +1,7 @@

-// +build !linux

+// +build !linux,!freebsd

 package zfs

+

+func checkRootdirFs(rootdir string) error {

+	return nil

+}