Re: [PATCH v3 03/17] f2fs: support regular file buffered writes on large folios

[Chao Yu <chao@kernel.org>]

On 10/10/26 00:12, Nanzhe Zhao wrote:
> +/*
> + * Drop the folio lock when a node was changed, then balance the
> + * filesystem and reacquire the lock.
> + *
> + * Return: true if the folio became unusable while unlocked (being
> + * truncated), false if the folio is still usable.
> + */
> +static bool f2fs_folio_may_unlock_balance_fs(struct folio *folio,

f2fs_balance_fs_folio_locked() ?

> @@ -4198,11 +4501,15 @@ static int f2fs_write_begin(const struct kiocb *iocb,
>   
>   	*foliop = folio;
>   
> +	/* Clamp the write length to the folio size. */
> +	blen = min_t(unsigned int, len,
> +		     folio_size(folio) - offset_in_folio(folio, pos));
> +
>   	if (f2fs_is_atomic_file(inode))
>   		err = prepare_atomic_write_begin(sbi, folio, pos, len,
>   					&blkaddr, &need_balance);
> -	else
> -		err = prepare_write_begin(sbi, folio, pos, len,
> +	else if (!folio_test_large(folio))
> +		err = prepare_write_begin(sbi, folio, pos, blen,
>   					&blkaddr, &need_balance);
>   	if (err)
>   		goto put_folio;
> @@ -4222,7 +4529,19 @@ static int f2fs_write_begin(const struct kiocb *iocb,
>   
>   	f2fs_folio_wait_writeback(folio, false, true);
>   
> -	if (len == folio_size(folio) || folio_test_uptodate(folio))
> +	if (folio_test_large(folio)) {
> +		err = prepare_large_folio_write_begin(inode,
> +					folio, pos, blen);

Is it possible that we can relocate prepare_large_folio_write_begin() after

else if (!folio_test_large(folio))
	err = prepare_write_begin(sbi, folio, pos, blen,
					&blkaddr, &need_balance);
else
	err = prepare_large_folio_write_begin(...);

Thanks,