Re: [Qemu-devel] [PATCH] block/nvme: call blk_drain in NVMe reset code to avoid lockups

[Igor Druzhinin]

On 06/11/2018 12:16, Igor Druzhinin wrote:
> When blk_flush called in NVMe reset path S/C queues are already freed
> which means that re-entering AIO handling loop having some IO requests
> unfinished will lockup or crash as their SG structures being potentially
> reused. Call blk_drain before freeing the queues to avoid this nasty
> scenario.
> 
> Signed-off-by: Igor Druzhinin <address@hidden>
> ---
>  hw/block/nvme.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index fc7dacb..cdf836e 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -797,6 +797,8 @@ static void nvme_clear_ctrl(NvmeCtrl *n)
>  {
>      int i;
>  
> +    blk_drain(n->conf.blk);
> +
>      for (i = 0; i < n->num_queues; i++) {
>          if (n->sq[i] != NULL) {
>              nvme_free_sq(n->sq[i], n);
> 

ping?