Hi Jens,
I have sent this already on April 25, I guess it was too late in the cycle
at that time. Apart from the usual maintenance and bug fixes this time comes
support for WRITE_SAME and lots of improvements for DISCARD.
At that time we had a discussion about (1) the all_zero() heuristic introduced
with [PATCH 04/30] drbd: Implement handling of thinly provisioned storage...
not being efficient, and about the (2) rs-discard-granularity configuration
parameter.
Regarding (1): I intend to work on block-devices being able to export their
allocation map by either FIEMAP or SEEK_HOLE/SEEK_DATA or both for the next
cycle. The I will change DRBD to use that as well.
Regarding (2): We need to announce the discard granularity when we create the
device/minor. At might it might be that there is no connection to the peer
node. So we are left with information about the discard granularity of the
local backing device only. Therefore we decided to delegate it to the
user/admin to provide the discard granularity for the resync process.
Please add it to your for-4.8/drivers branch.