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drbd: Receiving of delay_probes

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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>
This commit is contained in:
Philipp Reisner 2010-04-30 15:26:20 +02:00
parent 5223671bb0
commit 0ced55a3be
3 changed files with 118 additions and 1 deletions
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20
drivers/block/drbd/drbd_int.h
View File

@ -209,8 +209,11 @@ enum drbd_packets {
P_RS_IS_IN_SYNC = 0x22, /* meta socket */
P_SYNC_PARAM89 = 0x23, /* data socket, protocol version 89 replacement for P_SYNC_PARAM */
P_COMPRESSED_BITMAP = 0x24, /* compressed or otherwise encoded bitmap transfer */
/* P_CKPT_FENCE_REQ = 0x25, * currently reserved for protocol D */
/* P_CKPT_DISABLE_REQ = 0x26, * currently reserved for protocol D */
P_DELAY_PROBE = 0x27, /* is used on BOTH sockets */
P_MAX_CMD = 0x25,
P_MAX_CMD = 0x28,
P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
P_MAX_OPT_CMD = 0x101,
@ -540,6 +543,18 @@ struct p_compressed_bm {
u8 code[0];
} __packed;
struct p_delay_probe {
struct p_header head;
u32 seq_num; /* sequence number to match the two probe packets */
u32 offset; /* usecs the probe got sent after the reference time point */
} __packed;
struct delay_probe {
struct list_head list;
int seq_num;
struct timeval time;
};
/* DCBP: Drbd Compressed Bitmap Packet ... */
static inline enum drbd_bitmap_code
DCBP_get_code(struct p_compressed_bm *p)
@ -1028,6 +1043,9 @@ struct drbd_conf {
u64 ed_uuid; /* UUID of the exposed data */
struct mutex state_mutex;
char congestion_reason; /* Why we where congested... */
struct list_head delay_probes; /* protected by peer_seq_lock */
int data_delay; /* Delay of packets on the data-sock behind meta-sock */
atomic_t delay_seq; /* To generate sequence numbers of delay probes */
};
static inline struct drbd_conf *minor_to_mdev(unsigned int minor)

3
drivers/block/drbd/drbd_main.c
View File

@ -2608,6 +2608,7 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
atomic_set(&mdev->net_cnt, 0);
atomic_set(&mdev->packet_seq, 0);
atomic_set(&mdev->pp_in_use, 0);
atomic_set(&mdev->delay_seq, 0);
mutex_init(&mdev->md_io_mutex);
mutex_init(&mdev->data.mutex);
@ -2636,6 +2637,8 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
INIT_LIST_HEAD(&mdev->unplug_work.list);
INIT_LIST_HEAD(&mdev->md_sync_work.list);
INIT_LIST_HEAD(&mdev->bm_io_work.w.list);
INIT_LIST_HEAD(&mdev->delay_probes);
mdev->resync_work.cb = w_resync_inactive;
mdev->unplug_work.cb = w_send_write_hint;
mdev->md_sync_work.cb = w_md_sync;

96
drivers/block/drbd/drbd_receiver.c
View File

@ -3501,6 +3501,92 @@ static int receive_UnplugRemote(struct drbd_conf *mdev, struct p_header *h)
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 @@ static drbd_cmd_handler_f drbd_default_handler[] = {
[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 @@ static int got_OVResult(struct drbd_conf *mdev, struct p_header *h)
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 @@ static struct asender_cmd *get_asender_cmd(int cmd)
[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)