[PATCH v2 05/16] fs: Add RWF_ATOMIC and IOCB_ATOMIC flags for atomic write support

[Al Viro]

On Tue, Dec 12, 2023 at 11:08:33AM +0000, John Garry wrote:

> Add file mode flag FMODE_CAN_ATOMIC_WRITE, so files which do not have the
> flag set will have RWF_ATOMIC rejected and not just ignored.
> 
> Signed-off-by: Prasad Singamsetty <prasad.singamsetty at oracle.com>
> Signed-off-by: John Garry <john.g.garry at oracle.com>
> ---
>  include/linux/fs.h      | 8 ++++++++
>  include/uapi/linux/fs.h | 5 ++++-
>  2 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 70329c81be31..d725c194243c 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -185,6 +185,9 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
>  /* File supports async nowait buffered writes */
>  #define FMODE_BUF_WASYNC	((__force fmode_t)0x80000000)
>  
> +/* File supports atomic writes */
> +#define FMODE_CAN_ATOMIC_WRITE	((__force fmode_t)0x100000000)

Have you even tried to compile that on e.g. arm?