drbd: when receiving P_TRIM, zero-out partial unaligned chunks

[cascardo/linux.git] / include / linux / drbd_limits.h

diff --git a/include/linux/drbd_limits.h b/include/linux/drbd_limits.h
index 2e4aad8..a351c40 100644 (file)
--- a/include/linux/drbd_limits.h
+++ b/include/linux/drbd_limits.h
@@ -210,6 +210,12 @@
 #define DRBD_MD_FLUSHES_DEF    1
 #define DRBD_TCP_CORK_DEF      1
 #define DRBD_AL_UPDATES_DEF     1
+/* We used to ignore the discard_zeroes_data setting.
+ * To not change established (and expected) behaviour,
+ * by default assume that, for discard_zeroes_data=0,
+ * we can make that an effective discard_zeroes_data=1,
+ * if we only explicitly zero-out unaligned partial chunks. */
+#define DRBD_DISCARD_ZEROES_IF_ALIGNED 1
 
 #define DRBD_ALLOW_TWO_PRIMARIES_DEF   0
 #define DRBD_ALWAYS_ASBP_DEF   0