# Re: \[PATCH v6 4/6\] fs: make vfs\_fileattr\_\[get\|set\] return -EOPNOSUPP

- From: Arnd Bergmann \<arnd@arndb.de\>
- Date: 2025-10-06 11:44:08 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2025/10/326428
- Thread: https://ratatoskr.run/linux-api/2025/06/316331/t.md

```text
On Mon, Oct 6, 2025, at 13:09, Jiri Slaby wrote:
> On 30. 06. 25, 18:20, Andrey Albershteyn wrote:
>> Future patches will add new syscalls which use these functions. As
>> this interface won't be used for ioctls only, the EOPNOSUPP is more
>> appropriate return code.
>> 
>> This patch converts return code from ENOIOCTLCMD to EOPNOSUPP for
>> vfs_fileattr_get and vfs_fileattr_set. To save old behavior translate
>> EOPNOSUPP back for current users - overlayfs, encryptfs and fs/ioctl.c.
>> 
...
> dumps in 6.16:
> sf: ioctl: Operation not supported
>
> with the above patch:
> sf: ioctl: Inappropriate ioctl for device
>
>
> Is this expected?

This does look like an unintentional bug: As far as I can see, the
-ENOIOCTLCMD was previously used to indicate that a particular filesystem
does not have a fileattr_{get,set} callback at all, while individual
filesystems used EOPNOSUPP to indicate that a particular attribute
flag is unsupported. With the double conversion, both error codes
get turned into a single one.

     Arnd
```