cluster/afr: Keep child-up until ping-event

Problem:
If we have 2 bricks, brick-A and brick-B with brick-A within halo-max-latency
and brick-B more than halo-max-latency. If we set both halo-min, halo-max replicas
as '1'. In this case, brick-A comes online and then ping-latency will be updated for it.
When brick-B comes online, we have 2 up-bricks, so the code tries to find the brick with
worst latency to mark it down. Since Brick-B just came online it always had '0' latency
so brick-B used to be marked offline and Brick-B would eventually be the one to be
online even when brick-A is more suited.

Fix:
Consider latency of just-up child as HALO_MAX_LATENCY so that worst-child until
ping-latency is found as the just-up brick. Also keep ping-latency as -1 until
child-up during initialization.

BUG: 1567881
fixes bz#1567881
Change-Id: I148262fe505468190f0eb99225d0f6d57cdb6f04
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h
index 129670517f3..b96be62a910 100644
--- a/xlators/cluster/afr/src/afr.h
+++ b/xlators/cluster/afr/src/afr.h
@@ -36,6 +36,7 @@
 
 #define ARBITER_BRICK_INDEX 2
 
+#define AFR_HALO_MAX_LATENCY 99999
 typedef int (*afr_lock_cbk_t) (call_frame_t *frame, xlator_t *this);
 
 typedef int (*afr_read_txn_wind_t) (call_frame_t *frame, xlator_t *this, int subvol);