[RFC] rust: kernel: ioctl returns ENOTTY if not implemented

[RFC] rust: kernel: ioctl returns ENOTTY if not implemented

[Gioh Kim]

From: Gioh Kim <gurugio@gmail.com>

According to fs/ioctl.c, ioctl system call first test the cmd
value with do_vfs_ioctl. If the cmd is not supported command,
it calls vfs_ioctl. Then vfs_ioctl returns ENOTTY if ioctl is
not implemented.

Signed-off-by: Gioh Kim <gurugio@gmail.com>
---
 rust/kernel/file_operations.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rust/kernel/file_operations.rs b/rust/kernel/file_operations.rs
index cad665c0016f..c6f03938de97 100644
--- a/rust/kernel/file_operations.rs
+++ b/rust/kernel/file_operations.rs
@@ -662,7 +662,7 @@ pub trait FileOperations: Send + Sync + Sized {
         _file: &File,
         _cmd: &mut IoctlCommand,
     ) -> Result<i32> {
-        Err(Error::EINVAL)
+        Err(Error::ENOTTY)
     }
 
     /// Performs 32-bit IO control operations on that are specific to the file on 64-bit kernels.
@@ -673,7 +673,7 @@ pub trait FileOperations: Send + Sync + Sized {
         _file: &File,
         _cmd: &mut IoctlCommand,
     ) -> Result<i32> {
-        Err(Error::EINVAL)
+        Err(Error::ENOTTY)
     }
 
     /// Syncs pending changes to this file.
-- 
2.25.1

Re: [RFC] rust: kernel: ioctl returns ENOTTY if not implemented

[Wei Liu]

On Thu, Aug 19, 2021 at 10:44:22PM +0200, Gioh Kim wrote:
> From: Gioh Kim <gurugio@gmail.com>
> 
> According to fs/ioctl.c, ioctl system call first test the cmd
> value with do_vfs_ioctl. If the cmd is not supported command,
> it calls vfs_ioctl. Then vfs_ioctl returns ENOTTY if ioctl is
> not implemented.
> 
> Signed-off-by: Gioh Kim <gurugio@gmail.com>

FWIW:

Reviewed-by: Wei Liu <wei.liu@kernel.org>

> ---
>  rust/kernel/file_operations.rs | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/rust/kernel/file_operations.rs b/rust/kernel/file_operations.rs
> index cad665c0016f..c6f03938de97 100644
> --- a/rust/kernel/file_operations.rs
> +++ b/rust/kernel/file_operations.rs
> @@ -662,7 +662,7 @@ pub trait FileOperations: Send + Sync + Sized {
>          _file: &File,
>          _cmd: &mut IoctlCommand,
>      ) -> Result<i32> {
> -        Err(Error::EINVAL)
> +        Err(Error::ENOTTY)
>      }
>  
>      /// Performs 32-bit IO control operations on that are specific to the file on 64-bit kernels.
> @@ -673,7 +673,7 @@ pub trait FileOperations: Send + Sync + Sized {
>          _file: &File,
>          _cmd: &mut IoctlCommand,
>      ) -> Result<i32> {
> -        Err(Error::EINVAL)
> +        Err(Error::ENOTTY)
>      }
>  
>      /// Syncs pending changes to this file.
> -- 
> 2.25.1
> 

Re: [RFC] rust: kernel: ioctl returns ENOTTY if not implemented

[Miguel Ojeda]

Hi Gioh,

On Thu, Aug 19, 2021 at 10:45 PM Gioh Kim <gi-oh.kim@ionos.com> wrote:
>
> From: Gioh Kim <gurugio@gmail.com>
>
> According to fs/ioctl.c, ioctl system call first test the cmd
> value with do_vfs_ioctl. If the cmd is not supported command,
> it calls vfs_ioctl. Then vfs_ioctl returns ENOTTY if ioctl is
> not implemented.
>
> Signed-off-by: Gioh Kim <gurugio@gmail.com>

Thanks! Applying it.

(By the way, always try to match the `From` -- I understand you are
sending this as a personal contribution vs. your other commits in the
kernel).

Cheers,
Miguel