From 9de7e14a1a9c6bc4f9be6ccd9b951341a80dbd52 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Tue, 29 Aug 2017 10:20:38 +0200 Subject: drbd: new disk-option disable-write-same Some backend devices claim to support write-same, but would fail actual write-same requests. Allow to set (or toggle) whether or not DRBD tries to support write-same. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- include/linux/drbd_limits.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux/drbd_limits.h') diff --git a/include/linux/drbd_limits.h b/include/linux/drbd_limits.h index ddac68422a96..24ae1b9b76c7 100644 --- a/include/linux/drbd_limits.h +++ b/include/linux/drbd_limits.h @@ -209,12 +209,18 @@ #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_DISCARD_ZEROES_IF_ALIGNED_DEF 1 + +/* Some backends pretend to support WRITE SAME, + * but fail such requests when they are actually submitted. + * This is to tell DRBD to not even try. */ +#define DRBD_DISABLE_WRITE_SAME_DEF 0 #define DRBD_ALLOW_TWO_PRIMARIES_DEF 0 #define DRBD_ALWAYS_ASBP_DEF 0 -- cgit v1.2.3