[Qemu-devel] [PATCH V10 09/13] quorum: Add quorum_co_get_block_status.

[Benoît Canet]

From: Benoît Canet <ben...@irqsave.net>

Signed-off-by: Benoit Canet <ben...@irqsave.net>
---
 block/quorum.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/block/quorum.c b/block/quorum.c
index a47cd33..9b0718b 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -171,6 +171,22 @@ static int quorum_sha256_compare(QuorumVoteValue *a, 
QuorumVoteValue *b)
     return memcmp(a->h, b->h, HASH_LENGTH);
 }
 
+static int quorum_64bits_compare(QuorumVoteValue *a, QuorumVoteValue *b)
+{
+    int64_t i = a->l;
+    int64_t j = b->l;
+
+    if (i < j) {
+        return -1;
+    }
+
+    if (i > j) {
+        return 1;
+    }
+
+    return 0;
+}
+
 static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s,
                                    BlockDriverState *bs,
                                    QEMUIOVector *qiov,
@@ -587,6 +603,56 @@ static void quorum_invalidate_cache(BlockDriverState *bs)
     }
 }
 
+static int64_t coroutine_fn quorum_co_get_block_status(BlockDriverState *bs,
+                                                       int64_t sector_num,
+                                                       int nb_sectors,
+                                                       int *pnum)
+{
+    BDRVQuorumState *s = bs->opaque;
+    QuorumVoteVersion *winner = NULL;
+    QuorumVotes result_votes, num_votes;
+    QuorumVoteValue result_value, num_value;
+    int i, num;
+    int64_t result = 0;
+
+    QLIST_INIT(&result_votes.vote_list);
+    QLIST_INIT(&num_votes.vote_list);
+    result_votes.compare = quorum_64bits_compare;
+    num_votes.compare = quorum_64bits_compare;
+
+    for (i = 0; i < s->total; i++) {
+        result = bdrv_get_block_status(s->bs[i], sector_num, nb_sectors, &num);
+        /* skip failed requests */
+        if (result < 0) {
+            continue;
+        }
+        result_value.l = result & BDRV_BLOCK_DATA;
+        num_value.l = num;
+        quorum_count_vote(&result_votes, &result_value, i);
+        quorum_count_vote(&num_votes, &num_value, i);
+    }
+
+    winner = quorum_get_vote_winner(&result_votes);
+    result = winner->value.l;
+    if (winner->vote_count < s->threshold) {
+        result = -ERANGE;
+        goto free_exit;
+    }
+
+    winner = quorum_get_vote_winner(&num_votes);
+    if (winner->vote_count < s->threshold) {
+        result = -ERANGE;
+        goto free_exit;
+    }
+    *pnum = winner->value.l;
+
+free_exit:
+    quorum_free_vote_list(&result_votes);
+    quorum_free_vote_list(&num_votes);
+
+    return result;
+}
+
 static BlockDriver bdrv_quorum = {
     .format_name        = "quorum",
     .protocol_name      = "quorum",
@@ -598,6 +664,7 @@ static BlockDriver bdrv_quorum = {
     .bdrv_aio_readv     = quorum_aio_readv,
     .bdrv_aio_writev    = quorum_aio_writev,
     .bdrv_invalidate_cache = quorum_invalidate_cache,
+    .bdrv_co_get_block_status = quorum_co_get_block_status,
 };
 
 static void bdrv_quorum_init(void)
-- 
1.8.3.2