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.reis...@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenb...@linbit.com>
---
drivers/block/drbd/drbd_nl.c | 32 +++++++++++++++++++++++++++++---
include/linux/drbd_genl.h | 6 +++---
include/linux/drbd_limits.h | 6 ++++++
3 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index bb71e73..ee4642f 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1348,12 +1348,38 @@ static bool write_ordering_changed(struct disk_conf *a,
struct disk_conf *b)
a->disk_drain != b->disk_drain;
}
-static void sanitize_disk_conf(struct disk_conf *disk_conf, struct
drbd_backing_dev *nbc)
+static void sanitize_disk_conf(struct drbd_device *device, struct disk_conf
*disk_conf,
+ struct drbd_backing_dev *nbc)
{
+ struct request_queue * const q = nbc->backing_bdev->bd_disk->queue;
+
if (disk_conf->al_extents < DRBD_AL_EXTENTS_MIN)
disk_conf->al_extents = DRBD_AL_EXTENTS_MIN;
if (disk_conf->al_extents > drbd_al_extents_max(nbc))
disk_conf->al_extents = drbd_al_extents_max(nbc);
+
+ if (!blk_queue_discard(q) || !q->limits.discard_zeroes_data) {
+ disk_conf->rs_discard_granularity = 0; /* disable feature */
+ drbd_info(device, "rs_discard_granularity feature disabled\n");
+ }
+
+ if (disk_conf->rs_discard_granularity) {
+ int orig_value = disk_conf->rs_discard_granularity;
+ int remainder;
+
+ if (q->limits.discard_granularity >
disk_conf->rs_discard_granularity)
+ disk_conf->rs_discard_granularity =
q->limits.discard_granularity;
+
+ remainder = disk_conf->rs_discard_granularity %
q->limits.discard_granularity;
+ disk_conf->rs_discard_granularity += remainder;
+
+ if (disk_conf->rs_discard_granularity >
q->limits.max_discard_sectors << 9)
+ disk_conf->rs_discard_granularity =
q->limits.max_discard_sectors << 9;
+
+ if (disk_conf->rs_discard_granularity != orig_value)
+ drbd_info(device, "rs_discard_granularity changed to
%d\n",
+ disk_conf->rs_discard_granularity);
+ }
}
int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info)
@@ -1403,7 +1429,7 @@ int drbd_adm_disk_opts(struct sk_buff *skb, struct
genl_info *info)
if (!expect(new_disk_conf->resync_rate >= 1))
new_disk_conf->resync_rate = 1;
- sanitize_disk_conf(new_disk_conf, device->ldev);
+ sanitize_disk_conf(device, new_disk_conf, device->ldev);
if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;
@@ -1698,7 +1724,7 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info
*info)
if (retcode != NO_ERROR)
goto fail;
- sanitize_disk_conf(new_disk_conf, nbc);
+ sanitize_disk_conf(device, new_disk_conf, nbc);
if (drbd_get_max_capacity(nbc) < new_disk_conf->disk_size) {
drbd_err(device, "max capacity %llu smaller than disk size
%llu\n",
diff --git a/include/linux/drbd_genl.h b/include/linux/drbd_genl.h
index 2d0e5ad..ab649d8 100644
--- a/include/linux/drbd_genl.h
+++ b/include/linux/drbd_genl.h
@@ -123,14 +123,14 @@ GENL_struct(DRBD_NLA_DISK_CONF, 3, disk_conf,
__u32_field_def(13, DRBD_GENLA_F_MANDATORY, c_fill_target,
DRBD_C_FILL_TARGET_DEF)
__u32_field_def(14, DRBD_GENLA_F_MANDATORY, c_max_rate,
DRBD_C_MAX_RATE_DEF)
__u32_field_def(15, DRBD_GENLA_F_MANDATORY, c_min_rate,
DRBD_C_MIN_RATE_DEF)
+ __u32_field_def(20, DRBD_GENLA_F_MANDATORY, disk_timeout,
DRBD_DISK_TIMEOUT_DEF)
+ __u32_field_def(21, 0 /* OPTIONAL */, read_balancing,
DRBD_READ_BALANCING_DEF)
+ __u32_field_def(25, 0 /* OPTIONAL */, rs_discard_granularity,
DRBD_RS_DISCARD_GRANULARITY_DEF)
__flg_field_def(16, DRBD_GENLA_F_MANDATORY, disk_barrier,
DRBD_DISK_BARRIER_DEF)
__flg_field_def(17, DRBD_GENLA_F_MANDATORY, disk_flushes,
DRBD_DISK_FLUSHES_DEF)
__flg_field_def(18, DRBD_GENLA_F_MANDATORY, disk_drain,
DRBD_DISK_DRAIN_DEF)
__flg_field_def(19, DRBD_GENLA_F_MANDATORY, md_flushes,
DRBD_MD_FLUSHES_DEF)
- __u32_field_def(20, DRBD_GENLA_F_MANDATORY, disk_timeout,
DRBD_DISK_TIMEOUT_DEF)
- __u32_field_def(21, 0 /* OPTIONAL */, read_balancing,
DRBD_READ_BALANCING_DEF)
- /* 9: __u32_field_def(22, DRBD_GENLA_F_MANDATORY,
unplug_watermark, DRBD_UNPLUG_WATERMARK_DEF) */
__flg_field_def(23, 0 /* OPTIONAL */, al_updates,
DRBD_AL_UPDATES_DEF)
)
diff --git a/include/linux/drbd_limits.h b/include/linux/drbd_limits.h
index 8ac8c5d..2e4aad8 100644
--- a/include/linux/drbd_limits.h
+++ b/include/linux/drbd_limits.h
@@ -230,4 +230,10 @@
#define DRBD_SOCKET_CHECK_TIMEO_MAX DRBD_PING_TIMEO_MAX
#define DRBD_SOCKET_CHECK_TIMEO_DEF 0
#define DRBD_SOCKET_CHECK_TIMEO_SCALE '1'
+
+#define DRBD_RS_DISCARD_GRANULARITY_MIN 0
+#define DRBD_RS_DISCARD_GRANULARITY_MAX (1<<20) /* 1MiByte */
+#define DRBD_RS_DISCARD_GRANULARITY_DEF 0 /* disabled by default */
+#define DRBD_RS_DISCARD_GRANULARITY_SCALE '1' /* bytes */
+
#endif
--
1.9.1
