Patchwork [RFC,V7,03/13] quorum: Add quorum_aio_writev and its dependencies.

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Submitter Benoît Canet
Date Jan. 28, 2013, 1:22 p.m.
Message ID <1359379379-6017-4-git-send-email-benoit@irqsave.net>
Download mbox | patch
Permalink /patch/216192/
State New
Headers show

Comments

Benoît Canet - Jan. 28, 2013, 1:22 p.m.
Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 block/quorum.c |  113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
Stefan Hajnoczi - Jan. 28, 2013, 4:07 p.m.
On Mon, Jan 28, 2013 at 02:22:49PM +0100, Benoît Canet wrote:
> +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->aios = g_new0(QuorumSingleAIOCB, s->total);
> +    acb->qiovs = g_new0(QEMUIOVector, s->total);

->aios and ->qiovs lifetime matches so QEMUIOVector could be a field in
QuorumSingleAIOCB to simplify things.

Patch

diff --git a/block/quorum.c b/block/quorum.c
index 0524b63..8fa79db 100644
--- a/block/quorum.c
+++ b/block/quorum.c
@@ -52,11 +52,124 @@  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,
+};
+
+static void quorum_aio_bh(void *opaque)
+{
+    QuorumAIOCB *acb = opaque;
+    BDRVQuorumState *s = acb->bqs;
+    int ret;
+
+    ret = s->threshold <= acb->success_count ? 0 : -EIO;
+
+    qemu_bh_delete(acb->bh);
+    acb->common.cb(acb->common.opaque, ret);
+    if (acb->finished) {
+        *acb->finished = true;
+    }
+    g_free(acb->aios);
+    g_free(acb->qiovs);
+    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->aios = g_new0(QuorumSingleAIOCB, s->total);
+    acb->qiovs = g_new0(QEMUIOVector, s->total);
+
+    acb->bqs = s;
+    acb->qiov = qiov;
+    acb->bh = NULL;
+    acb->count = 0;
+    acb->success_count = 0;
+    acb->sector_num = sector_num;
+    acb->nb_sectors = nb_sectors;
+    acb->vote = NULL;
+    acb->vote_ret = 0;
+    acb->finished = NULL;
+
+    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;
+    }
+
+    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(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)