On Mon, Jun 13, 2022 at 11:08:58AM -0700, Mike Kravetz wrote:
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index eca1d0fabd7e..b0d0947a7e9b 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -584,41 +584,79 @@ static void hugetlb_vmtruncate(struct inode *inode, loff_t offset)
> remove_inode_hugepages(inode, offset, LLONG_MAX);
> }
>
> +static void hugetlbfs_zero_partial_page(struct hstate *h,
> + struct address_space *mapping,
> + unsigned long start,
This should be loff_t. Otherwise we can truncate on 32-bit machines.
> + unsigned long end)
> +{
> + pgoff_t idx = start >> huge_page_shift(h);
> + struct page *page;
> +
> + page = find_lock_page(mapping, idx);
> + if (!page)
> + return;
> +
> + start = start & ~huge_page_mask(h);
> + end = end & ~huge_page_mask(h);
> + if (!end)
> + end = huge_page_size(h);
> +
> + zero_user_segment(page, (unsigned int)start, (unsigned int)end);
> +
> + unlock_page(page);
> + put_page(page);
We haven't started converting hugetlbfs to folios yet, but here's how
that would look (which will save us converting it later):
folio = filemap_lock_folio(mapping, idx);
if (!folio)
return;
...
folio_zero_segment(folio, start, end);
folio_unlock(folio);
folio_put(folio);
Pretty much a 1-for-1 replacement.
