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[Qemu-devel] [PATCH 1/1] quorum: change vote rules for 64 bits hash
From: |
Changlong Xie |
Subject: |
[Qemu-devel] [PATCH 1/1] quorum: change vote rules for 64 bits hash |
Date: |
Mon, 15 Feb 2016 17:52:48 +0800 |
Before:
1) vote_count > max: winner = candidate, update max
2) vote_count <= max: do nothing
Current:
1) vote_count > max: winner = candidate, update max
2) vote_count = max: compare the value of winner with
candidate, if candidate->value.l == 0, winner = candidate,
else do nothing
3) vote_count < max: do nothing
Signed-off-by: Wen Congyang <address@hidden>
Signed-off-by: Changlong Xie <address@hidden>
---
block/quorum.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/block/quorum.c b/block/quorum.c
index a5ae4b8..e431ff4 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -446,7 +446,7 @@ static int quorum_compute_hash(QuorumAIOCB *acb, int i,
QuorumVoteValue *hash)
return 0;
}
-static QuorumVoteVersion *quorum_get_vote_winner(QuorumVotes *votes)
+static QuorumVoteVersion *quorum_get_vote_winner(QuorumVotes *votes, bool
vote_error)
{
int max = 0;
QuorumVoteVersion *candidate, *winner = NULL;
@@ -455,6 +455,12 @@ static QuorumVoteVersion
*quorum_get_vote_winner(QuorumVotes *votes)
if (candidate->vote_count > max) {
max = candidate->vote_count;
winner = candidate;
+ continue;
+ }
+ /* For 64 bit hash */
+ if (vote_error == true && candidate->vote_count == max
+ && candidate->value.l == 0) {
+ winner = candidate;
}
}
@@ -544,7 +550,7 @@ static int quorum_vote_error(QuorumAIOCB *acb)
}
if (error) {
- winner = quorum_get_vote_winner(&error_votes);
+ winner = quorum_get_vote_winner(&error_votes, false);
ret = winner->value.l;
}
@@ -609,7 +615,7 @@ static bool quorum_vote(QuorumAIOCB *acb)
}
/* vote to select the most represented version */
- winner = quorum_get_vote_winner(&acb->votes);
+ winner = quorum_get_vote_winner(&acb->votes, false);
/* if the winner count is smaller than threshold the read fails */
if (winner->vote_count < s->threshold) {
@@ -769,7 +775,7 @@ static coroutine_fn int quorum_co_flush(BlockDriverState
*bs)
quorum_count_vote(&error_votes, &result_value, i);
}
- winner = quorum_get_vote_winner(&error_votes);
+ winner = quorum_get_vote_winner(&error_votes, true);
result = winner->value.l;
quorum_free_vote_list(&error_votes);
--
1.9.3