Re: [PATCH V2] exfat: fdatasync flag should be same like generic_write_sync()

[Namjae Jeon]

On Thu, Jun 19, 2025 at 10:34 AM Zhengxu Zhang <zhengxu.zhang@xxxxxxxxxx> wrote:
>
> Test: androbench by default setting, use 64GB sdcard.
>  the random write speed:
>         without this patch 3.5MB/s
>         with this patch 7MB/s
>
> After patch "11a347fb6cef", the random write speed decreased significantly.
> the .write_iter() interface had been modified, and check the differences with
> generic_file_write_iter(), when calling generic_write_sync() and
> exfat_file_write_iter() to call vfs_fsync_range(), the fdatasync flag is wrong,
> and make not use the fdatasync mode, and make random write speed decreased.
>
> So use generic_write_sync() instead of vfs_fsync_range().
>
> Fixes: 11a347fb6cef ("exfat: change to get file size from DataLength")
>
> Signed-off-by: Zhengxu Zhang <zhengxu.zhang@xxxxxxxxxx>
Applied it to #dev.
Thanks!