Re: [Qemu-devel] [PATCH v4 3/4] rbd: check return values when scheduling aio

[Christian Brunner]

We should not leave this out:

Reviewed-by: Christian Brunner <address@hidden>

2011/5/24 Josh Durgin <address@hidden>:
> If scheduling fails, the number of outstanding I/Os must be correct,
> or there will be a hang when waiting for everything to be flushed.
>
> Reported-by: Stefan Hajnoczi <address@hidden>
> Signed-off-by: Josh Durgin <address@hidden>
> ---
>  block/rbd.c |   24 ++++++++++++++++++++----
>  1 files changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/block/rbd.c b/block/rbd.c
> index ff74e8b..c9f32e4 100644
> --- a/block/rbd.c
> +++ b/block/rbd.c
> @@ -580,10 +580,14 @@ static BlockDriverAIOCB 
> *rbd_aio_rw_vector(BlockDriverState *bs,
>     rbd_completion_t c;
>     int64_t off, size;
>     char *buf;
> +    int r;
>
>     BDRVRBDState *s = bs->opaque;
>
>     acb = qemu_aio_get(&rbd_aio_pool, bs, cb, opaque);
> +    if (!acb) {
> +        return NULL;
> +    }
>     acb->write = write;
>     acb->qiov = qiov;
>     acb->bounce = qemu_blockalign(bs, qiov->size);
> @@ -610,16 +614,28 @@ static BlockDriverAIOCB 
> *rbd_aio_rw_vector(BlockDriverState *bs,
>     rcb->buf = buf;
>     rcb->s = acb->s;
>     rcb->size = size;
> +    r = rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, 
> &c);
> +    if (r < 0) {
> +        goto failed;
> +    }
>
>     if (write) {
> -        rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, 
> &c);
> -        rbd_aio_write(s->image, off, size, buf, c);
> +        r = rbd_aio_write(s->image, off, size, buf, c);
>     } else {
> -        rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, 
> &c);
> -        rbd_aio_read(s->image, off, size, buf, c);
> +        r = rbd_aio_read(s->image, off, size, buf, c);
> +    }
> +
> +    if (r < 0) {
> +        goto failed;
>     }
>
>     return &acb->common;
> +
> +failed:
> +    qemu_free(rcb);
> +    s->qemu_aio_count--;
> +    qemu_aio_release(acb);
> +    return NULL;
>  }
>
>  static BlockDriverAIOCB *qemu_rbd_aio_readv(BlockDriverState *bs,
> --
> 1.7.2.3
>
>
>