Re: [RFC PATCH v2 1/7] statx: add I/O alignment information

Florian Weimer
2022-05-27T09:06:44Z

* Eric Biggers:

> diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
> index 1500a0f58041a..f822b23e81091 100644
> --- a/include/uapi/linux/stat.h
> +++ b/include/uapi/linux/stat.h
> @@ -124,9 +124,13 @@ struct statx {
> __u32 stx_dev_minor;
> /* 0x90 */
> __u64 stx_mnt_id;
> - __u64 __spare2;
> + __u32 stx_mem_align_dio; /* Memory buffer alignment for direct I/O */
> + __u32 stx_offset_align_dio; /* File offset alignment for direct I/O */
> /* 0xa0 */
> - __u64 __spare3[12]; /* Spare space for future expansion */
> + __u32 stx_offset_align_optimal; /* Optimal file offset alignment for I/O */
> + __u32 __spare2;
> + /* 0xa8 */
> + __u64 __spare3[11]; /* Spare space for future expansion */
> /* 0x100 */
> };

Are 32 bits enough? Would it make sense to store the base-2 logarithm
instead?

Thanks,
Florian