drbd: possibly disable discard support, if backend has discard_zeroes_data=0

Now that we have the discard_zeroes_if_aligned setting, we should also
check it when setting up our queue parameters on the primary,
not only on the receiving side.

We announce discard support,
UNLESS

 * we are connected to a peer that does not support TRIM
   on the DRBD protocol level.  Otherwise, it would either discard, or
   do a fallback to zero-out, depending on its backend and configuration.

 * our local backend does not support discards,
   or (discard_zeroes_data=0 AND discard_zeroes_if_aligned=no).

Signed-off-by: Philipp Reisner <[email protected]>
Signed-off-by: Lars Ellenberg <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions