Support FreeBSD on pkg/mount

Docker-DCO-1.1-Signed-off-by: Kato Kazuyoshi <kato.kazuyoshi@gmail.com> (github: kzys)

mount/flags.go

@@ -0,0 +1,62 @@
+package mount
+
+import (
+	"strings"
+)
+
+// Parse fstab type mount options into mount() flags
+// and device specific data
+func parseOptions(options string) (int, string) {
+	var (
+		flag int
+		data []string
+	)
+
+	flags := map[string]struct {
+		clear bool
+		flag  int
+	}{
+		"defaults":      {false, 0},
+		"ro":            {false, RDONLY},
+		"rw":            {true, RDONLY},
+		"suid":          {true, NOSUID},
+		"nosuid":        {false, NOSUID},
+		"dev":           {true, NODEV},
+		"nodev":         {false, NODEV},
+		"exec":          {true, NOEXEC},
+		"noexec":        {false, NOEXEC},
+		"sync":          {false, SYNCHRONOUS},
+		"async":         {true, SYNCHRONOUS},
+		"dirsync":       {false, DIRSYNC},
+		"remount":       {false, REMOUNT},
+		"mand":          {false, MANDLOCK},
+		"nomand":        {true, MANDLOCK},
+		"atime":         {true, NOATIME},
+		"noatime":       {false, NOATIME},
+		"diratime":      {true, NODIRATIME},
+		"nodiratime":    {false, NODIRATIME},
+		"bind":          {false, BIND},
+		"rbind":         {false, RBIND},
+		"private":       {false, PRIVATE},
+		"relatime":      {false, RELATIME},
+		"norelatime":    {true, RELATIME},
+		"strictatime":   {false, STRICTATIME},
+		"nostrictatime": {true, STRICTATIME},
+	}
+
+	for _, o := range strings.Split(options, ",") {
+		// If the option does not exist in the flags table or the flag
+		// is not supported on the platform,
+		// then it is a data value for a specific fs type
+		if f, exists := flags[o]; exists && f.flag != 0 {
+			if f.clear {
+				flag &= ^f.flag
+			} else {
+				flag |= f.flag
+			}
+		} else {
+			data = append(data, o)
+		}
+	}
+	return flag, strings.Join(data, ",")
+}