drbd: Introduce new disk config option rs-discard-granularity
authorPhilipp Reisner <philipp.reisner@linbit.com>
Mon, 13 Jun 2016 22:26:14 +0000 (00:26 +0200)
committerJens Axboe <axboe@fb.com>
Tue, 14 Jun 2016 03:43:04 +0000 (21:43 -0600)
commita5ca66c419410b4a26ab47b120d5424bd1d33700
treee8bcf9de1ec9ec9b51f2863c3e1ab9a7286d33ef
parent700ca8c04a0f4402f379055eec97351e0d6c0087
drbd: Introduce new disk config option rs-discard-granularity

As long as the value is 0 the feature is disabled. With setting
it to a positive value, DRBD limits and aligns its resync requests
to the rs-discard-granularity setting. If the sync source detects
all zeros in such a block, the resync target discards the range
on disk.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
drivers/block/drbd/drbd_nl.c
include/linux/drbd_genl.h
include/linux/drbd_limits.h