From d612d309e4c8401ad94c531678b59c4a8b7c41ce Mon Sep 17 00:00:00 2001 From: Philipp Reisner Date: Mon, 27 Dec 2010 10:53:28 +0100 Subject: [PATCH] drbd: No longer answer P_RS_DATA_REQUEST packets when in C_AHEAD mode When the sync source node replies to a P_RS_DATA_REQUEST packet when it is already in ahead mode. I.e. those two packets crossed each other on the wire, that may lead to diverging bitmaps. This never happens in a well-tuned-system. In a well-tuned- system the resync controller has reduced the resync speed to zero long before we got into ahead-mode. But we have to be prepared for the not-well-tuned-system of course as well. Because -> diverging bitmaps = non terminating resync. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_int.h | 3 ++- drivers/block/drbd/drbd_receiver.c | 12 +++++++++++- drivers/block/drbd/drbd_worker.c | 4 +++- 3 files changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index ec06e744be42..a529285b0cd3 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -205,8 +205,9 @@ enum drbd_packets { /* P_CKPT_DISABLE_REQ = 0x26, * currently reserved for protocol D */ P_DELAY_PROBE = 0x27, /* is used on BOTH sockets */ P_OUT_OF_SYNC = 0x28, /* Mark as out of sync (Outrunning), data socket */ + P_RS_CANCEL = 0x29, /* meta: Used to cancel RS_DATA_REQUEST packet by SyncSource */ - P_MAX_CMD = 0x28, + P_MAX_CMD = 0x2A, P_MAY_IGNORE = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */ P_MAX_OPT_CMD = 0x101, diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index f0a0f66fbe68..bf865bd83414 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -4361,7 +4361,16 @@ static int got_NegRSDReply(struct drbd_conf *mdev, struct p_header80 *h) if (get_ldev_if_state(mdev, D_FAILED)) { drbd_rs_complete_io(mdev, sector); - drbd_rs_failed_io(mdev, sector, size); + switch (be16_to_cpu(h->command)) { + case P_NEG_RS_DREPLY: + drbd_rs_failed_io(mdev, sector, size); + case P_RS_CANCEL: + break; + default: + D_ASSERT(0); + put_ldev(mdev); + return false; + } put_ldev(mdev); } @@ -4459,6 +4468,7 @@ static struct asender_cmd *get_asender_cmd(int cmd) [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_probe93), got_skip }, + [P_RS_CANCEL] = { sizeof(struct p_block_ack), got_NegRSDReply}, [P_MAX_CMD] = { 0, NULL }, }; if (cmd > P_MAX_CMD || asender_tbl[cmd].process == NULL) diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 7bfeb79e7105..1d7510ebaa43 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -988,7 +988,9 @@ int w_e_end_rsdata_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel) put_ldev(mdev); } - if (likely((e->flags & EE_WAS_ERROR) == 0)) { + if (mdev->state.conn == C_AHEAD) { + ok = drbd_send_ack(mdev, P_RS_CANCEL, e); + } else if (likely((e->flags & EE_WAS_ERROR) == 0)) { if (likely(mdev->state.pdsk >= D_INCONSISTENT)) { inc_rs_pending(mdev); ok = drbd_send_block(mdev, P_RS_DATA_REPLY, e); -- 2.39.5