Linux compat, umount2(2) flags

Older glibc <sys/mount.h> headers did not define all the available
umount2(2) flags.  Both MNT_FORCE and MNT_DETACH are supported in the
kernel back to 2.4.11 so we define them correctly if they are missing.

Closes #95

diff --git a/lib/libspl/include/sys/mount.h b/lib/libspl/include/sys/mount.h
index 9eb893f..d4ac6a9 100644 (file)
--- a/lib/libspl/include/sys/mount.h
+++ b/lib/libspl/include/sys/mount.h
@@ -55,7 +55,22 @@
 #define        MS_OWNER        0x10000000
 #define        MS_GROUP        0x08000000
 #define        MS_COMMENT      0x02000000
-#define        MS_FORCE        MNT_FORCE
-#define        MS_DETACH       MNT_DETACH
+
+/*
+ * Older glibc <sys/mount.h> headers did not define all the available
+ * umount2(2) flags.  Both MNT_FORCE and MNT_DETACH are supported in the
+ * kernel back to 2.4.11 so we define them correctly if they are missing.
+ */
+#ifdef MNT_FORCE
+# define MS_FORCE      MNT_FORCE
+#else
+# define MS_FORCE      0x00000001
+#endif /* MNT_FORCE */
+
+#ifdef MNT_DETACH
+# define MS_DETACH     MNT_DETACH
+#else
+# define MS_DETACH     0x00000002
+#endif /* MNT_DETACH */
 
 #endif /* _LIBSPL_SYS_MOUNT_H */