[PATCH 02/30] drbd: change bitmap write-out when leaving resync states
From: Philipp Reisner
Date: Mon Apr 25 2016 - 08:21:12 EST
From: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
When leaving resync states because of disconnect,
do the bitmap write-out synchronously in the drbd_disconnected() path.
When leaving resync states because we go back to AHEAD/BEHIND, or
because resync actually finished, or some disk was lost during resync,
trigger the write-out from after_state_ch().
The bitmap write-out for resync -> ahead/behind was missing completely before.
Note that this is all only an optimization to avoid double-resyncs of
already completed blocks in case this node crashes.
Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
Signed-off-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
---
drivers/block/drbd/drbd_receiver.c | 8 +++++---
drivers/block/drbd/drbd_state.c | 9 +++++++--
2 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 050aaa1..8b30ab5 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -4783,9 +4783,11 @@ static int drbd_disconnected(struct drbd_peer_device *peer_device)
drbd_md_sync(device);
- /* serialize with bitmap writeout triggered by the state change,
- * if any. */
- wait_event(device->misc_wait, !test_bit(BITMAP_IO, &device->flags));
+ if (get_ldev(device)) {
+ drbd_bitmap_io(device, &drbd_bm_write_copy_pages,
+ "write from disconnected", BM_LOCKED_CHANGE_ALLOWED);
+ put_ldev(device);
+ }
/* tcp_close and release of sendpage pages can be deferred. I don't
* want to use SO_LINGER, because apparently it can be deferred for
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 5a7ef78..59c6467 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -1934,12 +1934,17 @@ static void after_state_ch(struct drbd_device *device, union drbd_state os,
/* This triggers bitmap writeout of potentially still unwritten pages
* if the resync finished cleanly, or aborted because of peer disk
- * failure, or because of connection loss.
+ * failure, or on transition from resync back to AHEAD/BEHIND.
+ *
+ * Connection loss is handled in drbd_disconnected() by the receiver.
+ *
* For resync aborted because of local disk failure, we cannot do
* any bitmap writeout anymore.
+ *
* No harm done if some bits change during this phase.
*/
- if (os.conn > C_CONNECTED && ns.conn <= C_CONNECTED && get_ldev(device)) {
+ if ((os.conn > C_CONNECTED && os.conn < C_AHEAD) &&
+ (ns.conn == C_CONNECTED || ns.conn >= C_AHEAD) && get_ldev(device)) {
drbd_queue_bitmap_io(device, &drbd_bm_write_copy_pages, NULL,
"write from resync_finished", BM_LOCKED_CHANGE_ALLOWED);
put_ldev(device);
--
1.9.1