Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
In-Reply-To: <9122f83f-902b-3738-3b0e-f806df999c3f@linux.alibaba.com>
References: <20220720015538.15838-1-nbowler@draconx.ca> <9122f83f-902b-3738-3b0e-f806df999c3f@linux.alibaba.com>
From:   Nick Bowler <nbowler@draconx.ca>
Date:   Wed, 20 Jul 2022 23:56:39 -0400
Message-ID: <CADyTPExY4TOuy1pboWLiTRpjmKiLZkkGUqcnL1dGdSwviMapZA@mail.gmail.com>
Subject: Re: [PATCH] nvme: Define compat_ioctl again to unbreak 32-bit userspace.
To:     Guixin Liu <kanie@linux.alibaba.com>
Cc:     linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
        Christoph Hellwig <hch@lst.de>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On 2022-07-19, Guixin Liu <kanie@linux.alibaba.com> wrote:
> =E5=9C=A8 2022/7/20 09:55, Nick Bowler =E5=86=99=E9=81=93:
[...]
>> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>> index a2862a56fadc..30e105dbc178 100644
>> --- a/drivers/nvme/host/core.c
>> +++ b/drivers/nvme/host/core.c
>> @@ -2093,6 +2093,7 @@ static int nvme_report_zones(struct gendisk *disk,
>> sector_t sector,
>>   static const struct block_device_operations nvme_bdev_ops =3D {
>>   	.owner		=3D THIS_MODULE,
>>   	.ioctl		=3D nvme_ioctl,
>> +	.compat_ioctl	=3D nvme_ioctl,
>>   	.open		=3D nvme_open,
>>   	.release	=3D nvme_release,
>>   	.getgeo		=3D nvme_getgeo,
[...]
> Should this in the brace of "#ifdef CONFIG_COMPAT" and "#endif"?

I think it doesn't make any significant difference either way -- the
.compat_ioctl member is always present in the block_device_operations
structure.  Unconditional assignment thus seems more sensible to me.

v2 uses blkdev_compat_ptr_ioctl which expands to NULL for !CONFIG_COMPAT.

Thanks,
  Nick