Re: [PATCH 4/6] hw/nvme: Fix block accounting for compare

Klaus Jensen <[email protected]> Wed, 29 Jul 2026 14:44:13 +0200

Newsgroups	gmane.comp.emulators.qemu.block,gmane.comp.emulators.qemu
Message-ID	<[email protected]>

On Jul 24 17:23, Hanna Czenczek wrote:
> nvme_compare() starts block accounting for the operation, but
> nvme_compare_data_cb() (and nvme_compare_mdata_cb()) do not always
> finalize the cookie.  Specifically, there are a lot of error paths that
> do not call block_acct_failed().
> 
> Fix this by putting block_acct_done()/block_acct_failed() under the
> `out` labels of nvme_compare_data_cb() and nvme_compare_mdata_cb().
> 
> Signed-off-by: Hanna Czenczek <[email protected]>

Reviewed-by: Klaus Jensen <[email protected]>

> ---
>  hw/nvme/ctrl.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
> index 32e78881234..335498a2d73 100644
> --- a/hw/nvme/ctrl.c
> +++ b/hw/nvme/ctrl.c
> @@ -2388,7 +2388,6 @@ static void nvme_compare_mdata_cb(void *opaque, int ret)
>      trace_pci_nvme_compare_mdata_cb(nvme_cid(req));
>  
>      if (ret) {
> -        block_acct_failed(stats, acct);
>          req->status = NVME_UNRECOVERED_READ;
>  
>          trace_pci_nvme_err_aio(nvme_cid(req), strerror(-ret), req->status);
> @@ -2443,9 +2442,14 @@ static void nvme_compare_mdata_cb(void *opaque, int ret)
>          goto out;
>      }
>  
> -    block_acct_done(stats, acct);
>  
>  out:
> +    if (req->status == NVME_SUCCESS) {
> +        block_acct_done(stats, acct);
> +    } else {
> +        block_acct_failed(stats, acct);
> +    }
> +
>      qemu_iovec_destroy(&ctx->data.iov);
>      g_free(ctx->data.bounce);
>  
> @@ -2473,7 +2477,6 @@ static void nvme_compare_data_cb(void *opaque, int ret)
>      trace_pci_nvme_compare_data_cb(nvme_cid(req));
>  
>      if (ret) {
> -        block_acct_failed(stats, acct);
>          req->status = NVME_UNRECOVERED_READ;
>  
>          trace_pci_nvme_err_aio(nvme_cid(req), strerror(-ret), req->status);
> @@ -2512,9 +2515,13 @@ static void nvme_compare_data_cb(void *opaque, int ret)
>          return;
>      }
>  
> -    block_acct_done(stats, acct);
> -
>  out:
> +    if (req->status == NVME_SUCCESS) {
> +        block_acct_done(stats, acct);
> +    } else {
> +        block_acct_failed(stats, acct);
> +    }
> +
>      qemu_iovec_destroy(&ctx->data.iov);
>      g_free(ctx->data.bounce);
>      g_free(ctx);
> -- 
> 2.55.0
> 
>

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