drbd: Receiving of delay_probes
Delay_probes are new packets in the DRBD protocol, which allow
DRBD to know the current delay packets have on the data socket.
(relative to the meta data socket)
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index b27f4dd..fee0d24 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3501,6 +3501,92 @@
return TRUE;
}
+static void timeval_sub_us(struct timeval* tv, unsigned int us)
+{
+ tv->tv_sec -= us / 1000000;
+ us = us % 1000000;
+ if (tv->tv_usec > us) {
+ tv->tv_usec += 1000000;
+ tv->tv_sec--;
+ }
+ tv->tv_usec -= us;
+}
+
+static void got_delay_probe(struct drbd_conf *mdev, int from, struct p_delay_probe *p)
+{
+ struct delay_probe *dp;
+ struct list_head *le;
+ struct timeval now;
+ int seq_num;
+ int offset;
+ int data_delay;
+
+ seq_num = be32_to_cpu(p->seq_num);
+ offset = be32_to_cpu(p->offset);
+
+ spin_lock(&mdev->peer_seq_lock);
+ if (!list_empty(&mdev->delay_probes)) {
+ if (from == USE_DATA_SOCKET)
+ le = mdev->delay_probes.next;
+ else
+ le = mdev->delay_probes.prev;
+
+ dp = list_entry(le, struct delay_probe, list);
+
+ if (dp->seq_num == seq_num) {
+ list_del(le);
+ spin_unlock(&mdev->peer_seq_lock);
+ do_gettimeofday(&now);
+ timeval_sub_us(&now, offset);
+ data_delay =
+ now.tv_usec - dp->time.tv_usec +
+ (now.tv_sec - dp->time.tv_sec) * 1000000;
+
+ if (data_delay > 0)
+ mdev->data_delay = data_delay;
+
+ kfree(dp);
+ return;
+ }
+
+ if (dp->seq_num > seq_num) {
+ spin_unlock(&mdev->peer_seq_lock);
+ dev_warn(DEV, "Previous allocation failure of struct delay_probe?\n");
+ return; /* Do not alloca a struct delay_probe.... */
+ }
+ }
+ spin_unlock(&mdev->peer_seq_lock);
+
+ dp = kmalloc(sizeof(struct delay_probe), GFP_NOIO);
+ if (!dp) {
+ dev_warn(DEV, "Failed to allocate a struct delay_probe, do not worry.\n");
+ return;
+ }
+
+ dp->seq_num = seq_num;
+ do_gettimeofday(&dp->time);
+ timeval_sub_us(&dp->time, offset);
+
+ spin_lock(&mdev->peer_seq_lock);
+ if (from == USE_DATA_SOCKET)
+ list_add(&dp->list, &mdev->delay_probes);
+ else
+ list_add_tail(&dp->list, &mdev->delay_probes);
+ spin_unlock(&mdev->peer_seq_lock);
+}
+
+static int receive_delay_probe(struct drbd_conf *mdev, struct p_header *h)
+{
+ struct p_delay_probe *p = (struct p_delay_probe *)h;
+
+ ERR_IF(h->length != (sizeof(*p)-sizeof(*h))) return FALSE;
+ if (drbd_recv(mdev, h->payload, h->length) != h->length)
+ return FALSE;
+
+ got_delay_probe(mdev, USE_DATA_SOCKET, p);
+ return TRUE;
+}
+
typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, struct p_header *);
static drbd_cmd_handler_f drbd_default_handler[] = {
@@ -3524,6 +3610,7 @@
[P_OV_REQUEST] = receive_DataRequest,
[P_OV_REPLY] = receive_DataRequest,
[P_CSUM_RS_REQUEST] = receive_DataRequest,
+ [P_DELAY_PROBE] = receive_delay_probe,
/* anything missing from this table is in
* the asender_tbl, see get_asender_cmd */
[P_MAX_CMD] = NULL,
@@ -4300,6 +4387,14 @@
return TRUE;
}
+static int got_delay_probe_m(struct drbd_conf *mdev, struct p_header *h)
+{
+ struct p_delay_probe *p = (struct p_delay_probe *)h;
+
+ got_delay_probe(mdev, USE_META_SOCKET, p);
+ return TRUE;
+}
+
struct asender_cmd {
size_t pkt_size;
int (*process)(struct drbd_conf *mdev, struct p_header *h);
@@ -4324,6 +4419,7 @@
[P_BARRIER_ACK] = { sizeof(struct p_barrier_ack), got_BarrierAck },
[P_STATE_CHG_REPLY] = { sizeof(struct p_req_state_reply), got_RqSReply },
[P_RS_IS_IN_SYNC] = { sizeof(struct p_block_ack), got_IsInSync },
+ [P_DELAY_PROBE] = { sizeof(struct p_delay_probe), got_delay_probe_m },
[P_MAX_CMD] = { 0, NULL },
};
if (cmd > P_MAX_CMD || asender_tbl[cmd].process == NULL)