Re: [PATCH] block: fix ioctl return error with GENHD_FL_NO_PART

[Li Lingfeng <lilingfeng3@huawei.com>]

I don't think so.

GENHD_FL_NO_PART means "partition support is disabled". If users try to 
add or resize partition on the disk with this flag, kernel should remind 
them that the parameter of device is wrong.
So I think it's appropriate to return -EINVAL.

Thanks.

在 2023/10/17 16:09, Li Wang 写道:
> GENHD_FL_NO_PART means no device(-ENXIO), not parameter error(-EINVAL).
>
> test case with parted command:
> @dd if=/dev/zero of=./blk-file bs=1M count=200
> @losetup /dev/loop0 ./blk-file
> @parted -s /dev/loop0 mklabel MSDOS
> Error: Partition(s) 1, ..., 64 on /dev/loop0 have been written,
> but we have been unable to inform the kernel of the change,
> probably because it/they are in use. As a result,
> the old partition(s) will remain in use. You should reboot now
> before making further changes.
> @echo $?
> 1
>
> Fixes: 1a721de8489f ("block: don't add or resize partition on the disk with GENHD_FL_NO_PART")
> Signed-off-by: Li Wang <li.wang@windriver.com>
> ---
>   block/ioctl.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/ioctl.c b/block/ioctl.c
> index d5f5cd61efd7..701c64cd67e8 100644
> --- a/block/ioctl.c
> +++ b/block/ioctl.c
> @@ -21,7 +21,7 @@ static int blkpg_do_ioctl(struct block_device *bdev,
>   	long long start, length;
>   
>   	if (disk->flags & GENHD_FL_NO_PART)
> -		return -EINVAL;
> +		return -ENXIO;
>   	if (!capable(CAP_SYS_ADMIN))
>   		return -EACCES;
>   	if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))