From:   Dexuan Cui <decui@microsoft.com>
To:     Mohammed Gamal <mgamal@redhat.com>,
        "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>
CC:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Michael Kelley (LINUX)" <mikelley@microsoft.com>,
        "parri.andrea@gmail.com" <parri.andrea@gmail.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        "wei.liu@kernel.org" <wei.liu@kernel.org>,
        "vkuznets@redhat.com" <vkuznets@redhat.com>,
        "xxiong@redhat.com" <xxiong@redhat.com>
Subject: RE: [PATCH v2] Drivers: vmbus: Check for channel allocation before
 looking up relids
Thread-Topic: [PATCH v2] Drivers: vmbus: Check for channel allocation before
 looking up relids
Thread-Index: AQHZQGdq9M/Cyc8biEehOWpQHv+73q7SrIAg
Date:   Fri, 17 Feb 2023 06:25:28 +0000
Message-ID: <SA1PR21MB1335435701EBB35A9DD35892BFA19@SA1PR21MB1335.namprd21.prod.outlook.com>
References: <20230214112741.133900-1-mgamal@redhat.com>
In-Reply-To: <20230214112741.133900-1-mgamal@redhat.com>
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> From: Mohammed Gamal <mgamal@redhat.com>
> Sent: Tuesday, February 14, 2023 3:28 AM
> ...
> So Make relid2channel() check if vmbus channels is allocated first, and i=
f not
> print a warning and return NULL to the caller.
Can we change the above to:

Print a warning and error out in relid2channel() for a channel id that's in=
valid
in the second kernel.
=20
> --- a/drivers/hv/connection.c
> +++ b/drivers/hv/connection.c
> @@ -409,6 +409,10 @@ void vmbus_disconnect(void)
>   */
>  struct vmbus_channel *relid2channel(u32 relid)
>  {
> +	if (vmbus_connection.channels =3D=3D NULL) {
> +		WARN(1, "Requested relid=3D%u, but channel mapping not
> allocated!\n", relid);

WARN() may be too noisy. I suggest we use pr_warn() instead.

Can we make the line a little shorter:
        pr_warn("relid2channel: invalid channel id %u\n", relid);