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Date:   Thu, 5 Nov 2020 13:51:41 +0100
From:   Andrea Parri <parri.andrea@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     "K . Y . Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, linux-hyperv@vger.kernel.org,
        Andres Beltran <lkmlabelt@gmail.com>,
        Michael Kelley <mikelley@microsoft.com>,
        Saruhan Karademir <skarade@microsoft.com>,
        Juan Vazquez <juvazq@microsoft.com>,
        Dan Carpenter <dan.carpenter@oracle.com>, lkp@intel.com
Subject: Re: [PATCH v8 1/3] Drivers: hv: vmbus: Add vmbus_requestor data
 structure for VMBus hardening
Message-ID: <20201105125141.GA353914@andrea>
References: <20201104154027.319432-1-parri.andrea@gmail.com>
 <20201104154027.319432-2-parri.andrea@gmail.com>
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> @@ -300,6 +303,22 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
>  						     kv_list[i].iov_len);
>  	}
>  
> +	/*
> +	 * Allocate the request ID after the data has been copied into the
> +	 * ring buffer.  Once this request ID is allocated, the completion
> +	 * path could find the data and free it.
> +	 */
> +
> +	if (desc->flags == VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED) {
> +		rqst_id = vmbus_next_request_id(&channel->requestor, requestid);
> +		if (rqst_id == VMBUS_RQST_ERROR) {
> +			pr_err("No request id available\n");
> +			return -EAGAIN;

FYI, the lkp kernel test robot reported a missing call to
spin_unlock_irqrestore(&outring_info->ring_lock, flags) before the
above 'return': I'll address this in the next submission.

  Andrea