The patch titled Subject: fs/hugetlbfs/inode.c: mm/memory-failure.c has been added to the -mm mm-hotfixes-unstable branch. Its filename is fix-hugetlbfs-hwpoison-handling.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Sidhartha Kumar sidhartha.kumar@oracle.com Subject: fs/hugetlbfs/inode.c: mm/memory-failure.c fix hugetlbfs hwpoison handling Date: Thu, 11 Jan 2024 11:16:55 -0800

has_extra_refcount() makes the assumption that a ref count of 1 means the page is not referenced by other users. Commit a08c7193e4f1 (mm/filemap: remove hugetlb special casing in filemap.c) modifies __filemap_add_folio() by calling folio_ref_add(folio, nr); for all cases (including hugtetlb) where nr is the number of pages in the folio. We should check if the page is not referenced by other users by checking the page count against the number of pages rather than 1.

In hugetlbfs_read_iter(), folio_test_has_hwpoisoned() is testing the wrong flag as, in the hugetlb case, memory-failure code calls folio_test_set_hwpoison() to indicate poison. folio_test_hwpoison() is the correct function to test for that flag.

After these fixes, the hugetlb hwpoison read selftest passes all cases.

Link: https://lkml.kernel.org/r/20240111191655.295530-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar sidhartha.kumar@oracle.com Fixes: a08c7193e4f1 ("mm/filemap: remove hugetlb special casing in filemap.c") Closes: https://lore.kernel.org/linux-mm/20230713001833.3778937-1-jiaqiyan@google.co... Reported-by: Muhammad Usama Anjum usama.anjum@collabora.com Tested-by: Muhammad Usama Anjum usama.anjum@collabora.com Cc: James Houghton jthoughton@google.com Cc: Jiaqi Yan jiaqiyan@google.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Miaohe Lin linmiaohe@huawei.com Cc: Muchun Song muchun.song@linux.dev Cc: Naoya Horiguchi naoya.horiguchi@nec.com Cc: Yang Shi shy828301@gmail.com Cc: stable@vger.kernel.org [6.7+] Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

fs/hugetlbfs/inode.c | 2 +- mm/memory-failure.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)

--- a/fs/hugetlbfs/inode.c~fix-hugetlbfs-hwpoison-handling +++ a/fs/hugetlbfs/inode.c @@ -340,7 +340,7 @@ static ssize_t hugetlbfs_read_iter(struc } else { folio_unlock(folio);

- if (!folio_test_has_hwpoisoned(folio)) + if (!folio_test_hwpoison(folio)) want = nr; else { /* --- a/mm/memory-failure.c~fix-hugetlbfs-hwpoison-handling +++ a/mm/memory-failure.c @@ -979,7 +979,7 @@ struct page_state { static bool has_extra_refcount(struct page_state *ps, struct page *p, bool extra_pins) { - int count = page_count(p) - 1; + int count = page_count(p) - folio_nr_pages(page_folio(p));

if (extra_pins) count -= 1; _

Patches currently in -mm which might be from sidhartha.kumar@oracle.com are

fix-hugetlbfs-hwpoison-handling.patch maple_tree-fix-comment-describing-mas_node_count_gfp.patch