X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=lib%2Flibspl%2Finclude%2Fsys%2Fmount.h;h=145e785e3d520acf33db9b2fb9dbbbc0beb361c2;hb=756c3e5a9ce36461939a8dc421918e1c3a379fa6;hp=9eb893fe64bf6266ba8d44819106062023aa7bc0;hpb=afffb5cd102f340f3879f4d7af8988dd209b9b72;p=zfs.git

diff --git a/lib/libspl/include/sys/mount.h b/lib/libspl/include/sys/mount.h
index 9eb893f..145e785 100644
--- a/lib/libspl/include/sys/mount.h
+++ b/lib/libspl/include/sys/mount.h
@@ -55,7 +55,29 @@
 #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 */
+
+/*
+ * Overlay mount is default in Linux, but for solaris/zfs
+ * compatibility, MS_OVERLAY is defined to explicitly have the user
+ * provide a flag (-O) to mount over a non empty directory.
+ */
+#define MS_OVERLAY      0x00000004
 
 #endif /* _LIBSPL_SYS_MOUNT_H */