Commit a5ca66c4 authored by Philipp Reisner's avatar Philipp Reisner Committed by Jens Axboe

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: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 700ca8c0
......@@ -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",
......
......@@ -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)
)
......
......@@ -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
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