Re: [PATCH 1/6] hugetlb: open-code hugetlb folio lookup index conversion

[Mike Rapoport <rppt@kernel.org>]

Hi,

On Thu, Apr 09, 2026 at 05:41:52PM -0600, Jane Chu wrote:
> This patch removes `filemap_lock_hugetlb_folio()` and open-codes
> the index conversion at each call site, making it explicit when
> hugetlb code is translating a hugepage index into the base-page index
> expected by `filemap_lock_folio()`.  As part of that cleanup,
> it also uses a base-page index directly in `hugetlbfs_zero_partial_page()`,
> where the byte offset is already page-granular. Overall, the change
> makes the indexing model more obvious at the call sites and avoids
> hiding the huge-index to base-index conversion inside a helper.
> 
> Suggested-by: David Hildenbrand <david@kernel.org>
> Signed-off-by: Jane Chu <jane.chu@oracle.com>
> ---
>  fs/hugetlbfs/inode.c    | 20 ++++++++++----------
>  include/linux/hugetlb.h | 12 ------------
>  mm/hugetlb.c            |  4 ++--
>  3 files changed, 12 insertions(+), 24 deletions(-)
> 
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index cd6b22f6e2b1..cf79fb830377 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -242,9 +242,9 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  	struct hstate *h = hstate_file(file);
>  	struct address_space *mapping = file->f_mapping;
>  	struct inode *inode = mapping->host;
> -	unsigned long index = iocb->ki_pos >> huge_page_shift(h);
> +	unsigned long idx = iocb->ki_pos >> huge_page_shift(h);

Is it necessary to rename index to idx? 

>  	unsigned long offset = iocb->ki_pos & ~huge_page_mask(h);
> -	unsigned long end_index;
> +	unsigned long end_idx;
>  	loff_t isize;
>  	ssize_t retval = 0;
  
...

> @@ -652,10 +652,10 @@ static void hugetlbfs_zero_partial_page(struct hstate *h,
>  					loff_t start,
>  					loff_t end)
>  {
> -	pgoff_t idx = start >> huge_page_shift(h);
> +	pgoff_t index = start >> PAGE_SHIFT; 

And idx to index?

Maybe let's pick one and rename the other or just leave them be.

>  	struct folio *folio;
>  

-- 
Sincerely yours,
Mike.