Use strutil.shlex rather than strings

osutil/mkfs/mkfs.go

@@ -25,10 +25,10 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
-	"strings"
 
 	"github.com/snapcore/snapd/gadget/quantity"
 	"github.com/snapcore/snapd/osutil"
+	"github.com/snapcore/snapd/strutil/shlex"
 )
 
 // MakeFunc defines a function signature that is used by all of the mkfs.<filesystem>
@@ -111,8 +111,14 @@ func mkfsExt4(img, label, contentsRootDir string, deviceSize, sectorSize quantit
 		if fakerootFlags != "" {
 			// When executing fakeroot from a classic confinement snap the location of
 			// libfakeroot must be specified, or else it will be loaded from the host system
-			fakerootArgs := append(strings.Split(fakerootFlags, " "), "--")
-			mkfsArgs = append(fakerootArgs, mkfsArgs...)
+			flags, err := shlex.Split(fakerootFlags)
+			if err != nil {
+				return fmt.Errorf("cannot split fakeroot command: %v", err)
+			}
+			if len(fakerootFlags) > 0 {
+				fakerootArgs := append(flags, "--")
+				mkfsArgs = append(fakerootArgs, mkfsArgs...)
+			}
 		}
 		cmd = exec.Command("fakeroot", mkfsArgs...)
 	} else {