Re: [PATCH 2/2] hw/block/nvme: drain namespaces on sq deletion

[Minwoo Im <minwoo.im.dev@gmail.com>]

On 21-04-08 21:37:09, Klaus Jensen wrote:
> From: Klaus Jensen <k.jensen@samsung.com>
> 
> For most commands, when issuing an AIO, the BlockAIOCB is stored in the
> NvmeRequest aiocb pointer when the AIO is issued. The main use of this
> is cancelling AIOs when deleting submission queues (it is currently not
> used for Abort).
> 
> However, some commands like Dataset Management Zone Management Send
> (zone reset) may involve more than one AIO and here the AIOs are issued
> without saving a reference to the BlockAIOCB. This is a problem since
> nvme_del_sq() will attempt to cancel outstanding AIOs, potentially with
> an invalid BlockAIOCB since the aiocb pointer is not NULL'ed when the
> request structure is recycled.
> 
> Fix this by
> 
>   1. making sure the aiocb pointer is NULL'ed when requests are recycled
>   2. only attempt to cancel the AIO if the aiocb is non-NULL
>   3. if any AIOs could not be cancelled, drain all aio as a last resort.
> 
> Fixes: dc04d25e2f3f ("hw/block/nvme: add support for the format nvm command")
> Fixes: c94973288cd9 ("hw/block/nvme: add broadcast nsid support flush command")
> Fixes: e4e430b3d6ba ("hw/block/nvme: add simple copy command")
> Fixes: 5f5dc4c6a942 ("hw/block/nvme: zero out zones on reset")
> Fixes: 2605257a26b8 ("hw/block/nvme: add the dataset management command")
> Cc: Gollu Appalanaidu <anaidu.gollu@samsung.com>
> Cc: Minwoo Im <minwoo.im@samsung.com>
> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> ---
>  hw/block/nvme.c | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index 94bc373260be..3c4297e38a52 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -470,6 +470,7 @@ static void nvme_req_clear(NvmeRequest *req)
>  {
>      req->ns = NULL;
>      req->opaque = NULL;
> +    req->aiocb = NULL;
>      memset(&req->cqe, 0x0, sizeof(req->cqe));
>      req->status = NVME_SUCCESS;
>  }
> @@ -3681,6 +3682,7 @@ static uint16_t nvme_del_sq(NvmeCtrl *n, NvmeRequest *req)
>      NvmeSQueue *sq;
>      NvmeCQueue *cq;
>      uint16_t qid = le16_to_cpu(c->qid);
> +    int nsid;

Even we don't have fully supported number of namespaces in this device
(0xFFFFFFFF), can we have this one with `uint32_t` ?

Otherwise, looks good to me.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>