From e4f925e12ea5daaa9baf2dd5af9c4951721dae95 Mon Sep 17 00:00:00 2001 From: Philipp Reisner Date: Wed, 17 Mar 2010 14:18:41 +0100 Subject: [PATCH] drbd: Do not upgrade state to Outdated if already Inconsistent [Bugz 277] There was a race condition: In a situation with a SyncSource+Primary and a SyncTarget+Secondary node, and a resync dependency to some other device. After both nodes decided to do the resync, the other device finishes its resync process. At that time SyncSource already sent the P_SYNC_UUID packet, and already updated its peer disk state to Inconsistent. The SyncTarget node waits for the P_SYNC_UUID and sends a state packet to report the resync dependency change. That packet still carries a disk state of Outdated. Impact: If application writes come in, during that time on the Primary node, those do not get replicated, and the out-of-sync counter gets increased. => The completion of resync is not detected on the primary node. => stalled. Those blocks get resync'ed with the next resync, since the are get marked as out-of-sync in the bitmap. In order to fix this, we filter out that wrong state change in the sanitize_state() function. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index db7a07a..8f84a9f 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -840,7 +840,7 @@ static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state break; case C_WF_BITMAP_S: case C_PAUSED_SYNC_S: - ns.pdsk = D_OUTDATED; + ns.pdsk = os.pdsk > D_OUTDATED ? D_OUTDATED : os.pdsk; break; case C_SYNC_SOURCE: ns.pdsk = D_INCONSISTENT; -- 2.7.4