Re: [PATCH v2 3/3] exfat: drain in-flight DIO before buffered write fallback

[Chi Zhiling]

On 9/26/26 3:26 PM, Jiale Yao wrote:
> diff --git a/fs/exfat/file.c b/fs/exfat/file.c
> index a2a9ee1a2004..cf5ccbd54823 100644
> --- a/fs/exfat/file.c
> +++ b/fs/exfat/file.c
> @@ -807,6 +807,12 @@ static ssize_t exfat_fallback_buffered_write(struct kiocb *iocb,
>   
>   	iocb->ki_flags &= ~IOCB_DIRECT;
>   
> +	/*
> +	 * Prevent concurrent direct I/O and buffered I/O to the same file
> +	 * range. Wait for in-flight DIO to finish before dirtying pages.
> +	 */
> +	inode_dio_wait(file_inode(iocb->ki_filp));

This change is correct, but the comment is not accurate because the 
function you modified is not part of the buffered I/O path in exFAT.

You can add inode_dio_wait() to both exfat_file_write_iter() and 
exfat_fallback_buffered_write(), and move the comment to 
exfat_file_write_iter().

> +
>   	written = iomap_file_buffered_write(iocb, from, &exfat_write_iomap_ops,
>   			NULL, NULL);
>   	if (written < 0)