From a5ca66c419410b4a26ab47b120d5424bd1d33700 Mon Sep 17 00:00:00 2001 From: Philipp Reisner Date: Tue, 14 Jun 2016 00:26:14 +0200 Subject: 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 Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_nl.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) (limited to 'drivers/block/drbd') diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index fad03e4feef6..99339dfe4389 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", -- cgit v1.2.3