[PATCH v2 16/37] fs: hugetlbfs: cleanup folio in adjust_range_hwpoison()

David Hildenbrand
2025-09-01T15:08:54Z

Let's cleanup and simplify the function a bit.

Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
fs/hugetlbfs/inode.c | 36 ++++++++++++------------------------
1 file changed, 12 insertions(+), 24 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index c5a46d10afaa0..3cfdf4091001f 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -192,37 +192,25 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
* Someone wants to read @bytes from a HWPOISON hugetlb @folio from @offset.
* Returns the maximum number of bytes one can read without touching the 1st raw
* HWPOISON page.
- *
- * The implementation borrows the iteration logic from copy_page_to_iter*.
*/
static size_t adjust_range_hwpoison(struct folio *folio, size_t offset,
size_t bytes)
{
- struct page *page;
- size_t n = 0;
- size_t res = 0;
-
- /* First page to start the loop. */
- page = folio_page(folio, offset / PAGE_SIZE);
- offset %= PAGE_SIZE;
- while (1) {
- if (is_raw_hwpoison_page_in_hugepage(page))
- break;
+ struct page *page = folio_page(folio, offset / PAGE_SIZE);
+ size_t safe_bytes;
+
+ if (is_raw_hwpoison_page_in_hugepage(page))
+ return 0;
+ /* Safe to read the remaining bytes in this page. */
+ safe_bytes = PAGE_SIZE - (offset % PAGE_SIZE);
+ page++;

- /* Safe to read n bytes without touching HWPOISON subpage. */
- n = min(bytes, (size_t)PAGE_SIZE - offset);
- res += n;
- bytes -= n;
- if (!bytes || !n)
+ /* Check each remaining page as long as we are not done yet. */
+ for (; safe_bytes < bytes; safe_bytes += PAGE_SIZE, page++)
+ if (is_raw_hwpoison_page_in_hugepage(page))
break;
- offset += n;
- if (offset == PAGE_SIZE) {
- page++;
- offset = 0;
- }
- }

- return res;
+ return min(safe_bytes, bytes);
}

/*
--
2.50.1