[Qemu-devel] [PATCH V9 03/11] quorum: Add quorum_aio_writev and its dependencies.

["Benoît Canet" <benoit@irqsave.net>]

Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 block/quorum.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)

diff --git a/block/quorum.c b/block/quorum.c
index 9557e61..b49e3c6 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -64,11 +64,134 @@ struct QuorumAIOCB {
     int vote_ret;
 };
 
+static void quorum_aio_cancel(BlockDriverAIOCB *blockacb)
+{
+    QuorumAIOCB *acb = container_of(blockacb, QuorumAIOCB, common);
+    bool finished = false;
+
+    /* Wait for the request to finish */
+    acb->finished = &finished;
+    while (!finished) {
+        qemu_aio_wait();
+    }
+}
+
+static AIOCBInfo quorum_aiocb_info = {
+    .aiocb_size         = sizeof(QuorumAIOCB),
+    .cancel             = quorum_aio_cancel,
+};
+
+/* return the first error code get by each individual callbacks */
+static int quorum_get_first_error(QuorumAIOCB *acb)
+{
+    BDRVQuorumState *s = acb->bqs;
+    int i, ret = 0;
+
+    for (i = 0; i < s->total; i++) {
+        ret = acb->aios[i].ret;
+        if (ret) {
+            return ret;
+        }
+    }
+
+    /* should not pass here */
+    assert(false);
+}
+
+static void quorum_aio_finalize(QuorumAIOCB *acb)
+{
+    BDRVQuorumState *s = acb->bqs;
+    int ret;
+
+    ret = s->threshold <= acb->success_count ? 0 : quorum_get_first_error(acb);
+
+    acb->common.cb(acb->common.opaque, ret);
+    if (acb->finished) {
+        *acb->finished = true;
+    }
+    g_free(acb->aios);
+    qemu_aio_release(acb);
+}
+
+static QuorumAIOCB *quorum_aio_get(BDRVQuorumState *s,
+                                   BlockDriverState *bs,
+                                   QEMUIOVector *qiov,
+                                   uint64_t sector_num,
+                                   int nb_sectors,
+                                   BlockDriverCompletionFunc *cb,
+                                   void *opaque)
+{
+    QuorumAIOCB *acb = qemu_aio_get(&quorum_aiocb_info, bs, cb, opaque);
+    int i;
+
+    acb->bqs = s;
+    acb->sector_num = sector_num;
+    acb->nb_sectors = nb_sectors;
+    acb->qiov = qiov;
+    acb->aios = g_new0(QuorumSingleAIOCB, s->total);
+    acb->count = 0;
+    acb->success_count = 0;
+    acb->finished = NULL;
+    acb->is_read = false;
+    acb->vote_ret = 0;
+
+    for (i = 0; i < s->total; i++) {
+        acb->aios[i].buf = NULL;
+        acb->aios[i].ret = 0;
+        acb->aios[i].parent = acb;
+    }
+
+    return acb;
+}
+
+static void quorum_aio_cb(void *opaque, int ret)
+{
+    QuorumSingleAIOCB *sacb = opaque;
+    QuorumAIOCB *acb = sacb->parent;
+    BDRVQuorumState *s = acb->bqs;
+
+    sacb->ret = ret;
+    acb->count++;
+    if (ret == 0) {
+        acb->success_count++;
+    }
+    assert(acb->count <= s->total);
+    assert(acb->success_count <= s->total);
+    if (acb->count < s->total) {
+        return;
+    }
+
+    quorum_aio_finalize(acb);
+}
+
+static BlockDriverAIOCB *quorum_aio_writev(BlockDriverState *bs,
+                                          int64_t sector_num,
+                                          QEMUIOVector *qiov,
+                                          int nb_sectors,
+                                          BlockDriverCompletionFunc *cb,
+                                          void *opaque)
+{
+    BDRVQuorumState *s = bs->opaque;
+    QuorumAIOCB *acb = quorum_aio_get(s, bs, qiov, sector_num, nb_sectors,
+                                      cb, opaque);
+    int i;
+
+    for (i = 0; i < s->total; i++) {
+        acb->aios[i].aiocb = bdrv_aio_writev(&s->bs[i], sector_num, qiov,
+                                             nb_sectors, &quorum_aio_cb,
+                                             &acb->aios[i]);
+    }
+
+    return &acb->common;
+}
+
 static BlockDriver bdrv_quorum = {
     .format_name        = "quorum",
     .protocol_name      = "quorum",
 
     .instance_size      = sizeof(BDRVQuorumState),
+
+    .bdrv_aio_writev    = quorum_aio_writev,
 };
 
 static void bdrv_quorum_init(void)
-- 
1.8.1.2