Re: [PATCH v2 1/5] netfs: clear post-EOF pagecache when extending a file via write

[Matthew Wilcox <willy@infradead.org>]

On Mon, Sep 21, 2026 at 08:07:51PM -0300, Paulo Alcantara wrote:
> +	int netfs_clear_stale_post_eof(struct inode *inode, unsigned long long from,
> +				       unsigned long long to, bool nowait);

Should this be uoff_t?  Or even loff_t?

> +int netfs_clear_stale_post_eof(struct inode *inode, unsigned long long from,
> +			       unsigned long long to, bool nowait)
> +{
> +	struct address_space *mapping = inode->i_mapping;
> +	fgf_t fgp = FGP_LOCK;
> +	struct folio *folio;
> +
> +	if (from >= to)
> +		return 0;
> +
> +	if (nowait)
> +		fgp |= FGP_NOWAIT;
> +
> +	folio = __filemap_get_folio(mapping, from >> PAGE_SHIFT, fgp, 0);
> +	if (IS_ERR(folio))
> +		return PTR_ERR(folio) == -EAGAIN ? -EAGAIN : 0;
> +
> +	if (folio_mkclean(folio))
> +		folio_mark_dirty(folio);
> +
> +	if (folio_test_uptodate(folio)) {
> +		size_t end = umin(to - folio_pos(folio), folio_size(folio));
> +		size_t offset = offset_in_folio(folio, from);
> +
> +		folio_zero_segment(folio, offset, end);
> +	}
> +
> +	folio_unlock(folio);
> +	folio_put(folio);
> +	return 0;
> +}
> +EXPORT_SYMBOL(netfs_clear_stale_post_eof);

This looks suspiciously similar to pagecache_isize_extended() but does
not mention it.  So any updates to that function will probably imss this
one.  That's not great.