From 5052fee2c7302390b0a719a0613813484006757d Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Tue, 14 Jun 2016 00:26:24 +0200 Subject: [PATCH] drbd: finish resync on sync source only by notification from sync target If the replication link breaks exactly during "resync finished" detection, finishing too early on the sync source could again lead to UUIDs rotated too fast, and potentially a spurious full resync on next handshake. Always wait for explicit resync finished state change notification from the sync target. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_actlog.c | 16 ++++++++++++---- drivers/block/drbd/drbd_int.h | 19 ++++++++++++++----- 2 files changed, 26 insertions(+), 9 deletions(-) diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c index 265b2b6ebdec..cafa9c42fbdd 100644 --- a/drivers/block/drbd/drbd_actlog.c +++ b/drivers/block/drbd/drbd_actlog.c @@ -770,10 +770,18 @@ static bool lazy_bitmap_update_due(struct drbd_device *device) static void maybe_schedule_on_disk_bitmap_update(struct drbd_device *device, bool rs_done) { - if (rs_done) - set_bit(RS_DONE, &device->flags); - /* and also set RS_PROGRESS below */ - else if (!lazy_bitmap_update_due(device)) + if (rs_done) { + struct drbd_connection *connection = first_peer_device(device)->connection; + if (connection->agreed_pro_version <= 95 || + is_sync_target_state(device->state.conn)) + set_bit(RS_DONE, &device->flags); + /* and also set RS_PROGRESS below */ + + /* Else: rather wait for explicit notification via receive_state, + * to avoid uuids-rotated-too-fast causing full resync + * in next handshake, in case the replication link breaks + * at the most unfortunate time... */ + } else if (!lazy_bitmap_update_due(device)) return; drbd_device_post_work(device, RS_PROGRESS); diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 9c68ec54a247..c5dbc85c9b4f 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -2102,13 +2102,22 @@ static inline void _sub_unacked(struct drbd_device *device, int n, const char *f ERR_IF_CNT_IS_NEGATIVE(unacked_cnt, func, line); } +static inline bool is_sync_target_state(enum drbd_conns connection_state) +{ + return connection_state == C_SYNC_TARGET || + connection_state == C_PAUSED_SYNC_T; +} + +static inline bool is_sync_source_state(enum drbd_conns connection_state) +{ + return connection_state == C_SYNC_SOURCE || + connection_state == C_PAUSED_SYNC_S; +} + static inline bool is_sync_state(enum drbd_conns connection_state) { - return - (connection_state == C_SYNC_SOURCE - || connection_state == C_SYNC_TARGET - || connection_state == C_PAUSED_SYNC_S - || connection_state == C_PAUSED_SYNC_T); + return is_sync_source_state(connection_state) || + is_sync_target_state(connection_state); } /** -- 2.20.1