Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.33 as permitted sender) client-ip=23.128.96.33;
Feedback-ID: iccd040f4:Fastmail
From:   Zi Yan <zi.yan@sent.com>
To:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        linux-mips@vger.kernel.org
Cc:     Zi Yan <ziy@nvidia.com>, Andrew Morton <akpm@linux-foundation.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        David Hildenbrand <david@redhat.com>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Muchun Song <muchun.song@linux.dev>,
        "Mike Rapoport (IBM)" <rppt@kernel.org>, stable@vger.kernel.org,
        Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH v3 4/5] fs: use nth_page() in place of direct struct page manipulation.
Date:   Wed, 13 Sep 2023 16:12:47 -0400
Message-Id: <20230913201248.452081-5-zi.yan@sent.com>
In-Reply-To: <20230913201248.452081-1-zi.yan@sent.com>
References: <20230913201248.452081-1-zi.yan@sent.com>
Reply-To: Zi Yan <ziy@nvidia.com>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

From: Zi Yan <ziy@nvidia.com>

When dealing with hugetlb pages, struct page is not guaranteed to be
contiguous on SPARSEMEM without VMEMMAP. Use nth_page() to handle it
properly.

Fixes: 38c1ddbde6c6 ("hugetlbfs: improve read HWPOISON hugepage")
Cc: <stable@vger.kernel.org>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
---
 fs/hugetlbfs/inode.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 7083fa0caaab..14d3d28e41b0 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -295,7 +295,7 @@ static size_t adjust_range_hwpoison(struct page *page, =
size_t offset, size_t byt
 	size_t res =3D 0;
=20
 	/* First subpage to start the loop. */
-	page +=3D offset / PAGE_SIZE;
+	page =3D nth_page(page, offset / PAGE_SIZE);
 	offset %=3D PAGE_SIZE;
 	while (1) {
 		if (is_raw_hwpoison_page_in_hugepage(page))
@@ -309,7 +309,7 @@ static size_t adjust_range_hwpoison(struct page *page, =
size_t offset, size_t byt
 			break;
 		offset +=3D n;
 		if (offset =3D=3D PAGE_SIZE) {
-			page++;
+			page =3D nth_page(page, 1);
 			offset =3D 0;
 		}
 	}
--=20
2.40.1