[Qemu-devel] [RFC V2 06/10] quorum: Add quorum_aio_writev and its dependencies.

["Benoît Canet" <benoit.canet@gmail.com>]

Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 block/quorum.c |  110 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/block/quorum.c b/block/quorum.c
index 5cd7083..e6d2274 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -133,6 +133,114 @@ static int64_t quorum_getlength(BlockDriverState *bs)
     return 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 AIOPool quorum_aio_pool = {
+    .aiocb_size         = sizeof(QuorumAIOCB),
+    .cancel             = quorum_aio_cancel,
+};
+
+static int quorum_check_ret(QuorumAIOCB *acb)
+{
+    int i, j;
+
+    for (i = 0, j = 0; i <= 2; i++) {
+        if (acb->aios[0].ret) {
+            j++;
+        }
+    }
+
+    if (j > 1) {
+        return -EIO;
+    }
+
+    return 0;
+}
+
+static void quorum_aio_bh(void *opaque)
+{
+    QuorumAIOCB *acb = opaque;
+
+    qemu_bh_delete(acb->bh);
+    acb->common.cb(acb->common.opaque, quorum_check_ret(acb));
+    if (acb->finished) {
+        *acb->finished = true;
+    }
+    qemu_aio_release(acb);
+}
+
+static QuorumAIOCB *quorum_aio_get(BlockDriverState *bs,
+                                 QEMUIOVector *qiov,
+                                 int64_t sector_num,
+                                 int nb_sectors,
+                                 BlockDriverCompletionFunc *cb,
+                                 void *opaque)
+{
+    QuorumAIOCB *acb = qemu_aio_get(&quorum_aio_pool, bs, cb, opaque);
+    int i;
+
+    acb->qiov = qiov;
+    acb->bh = NULL;
+    acb->count = 0;
+    acb->sector_num = sector_num;
+    acb->nb_sectors = nb_sectors;
+    acb->vote = NULL;
+    acb->vote_ret = 0;
+
+    for (i = 0; i <= 2; 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;
+
+    sacb->ret = ret;
+    acb->count++;
+    assert(acb->count <= 3);
+    if (acb->count == 3) {
+        acb->bh = qemu_bh_new(quorum_aio_bh, acb);
+        qemu_bh_schedule(acb->bh);
+    }
+}
+
+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(bs, qiov, sector_num, nb_sectors,
+                                    cb, opaque);
+    int i;
+
+    for (i = 0; i <= 2; 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",
@@ -143,6 +251,8 @@ static BlockDriver bdrv_quorum = {
 
     .bdrv_file_open     = quorum_open,
     .bdrv_close         = quorum_close,
+
+    .bdrv_aio_writev    = quorum_aio_writev,
 };
 
 static void bdrv_quorum_init(void)
-- 
1.7.9.5