Commit 399c6fe8 authored by Sidhartha Kumar's avatar Sidhartha Kumar Committed by Kefeng Wang
Browse files

fs/hugetlbfs/inode.c: mm/memory-failure.c: fix hugetlbfs hwpoison handling 

mainline inclusion
from mainline-v6.8-rc3
commit 19d3e221807772f8443e565234a6fdc5a2b09d26
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9H84X
CVE: NA

-------------------------------------------------

has_extra_refcount() makes the assumption that the page cache adds a ref
count of 1 and subtracts this in the extra_pins case.  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 adjust the number of references coming from the page cache by
subtracing 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/20240112180840.367006-1-sidhartha.kumar@oracle.com


Fixes: a08c7193e4f1 ("mm/filemap: remove hugetlb special casing in filemap.c")
Signed-off-by: default avatarSidhartha Kumar <sidhartha.kumar@oracle.com>
Closes: https://lore.kernel.org/linux-mm/20230713001833.3778937-1-jiaqiyan@google.com/T/#m8e1469119e5b831bbd05d495f96b842e4a1c5519


Reported-by: default avatarMuhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: default avatarMuhammad Usama Anjum <usama.anjum@collabora.com>
Acked-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Acked-by: default avatarMuchun Song <muchun.song@linux.dev>
Cc: James Houghton <jthoughton@google.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>	[6.7+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 19d3e221807772f8443e565234a6fdc5a2b09d26)
Signed-off-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
parent 859471ce

fs/hugetlbfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -375,7 +375,7 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to) 
		} else {

			folio_unlock(folio);



			if (!folio_test_has_hwpoisoned(folio))

			if (!folio_test_hwpoison(folio))

				want = nr;

			else {

				/*

mm/memory-failure.c

+1 −1
Original line number Diff line number Diff line
@@ -978,7 +978,7 @@ static bool has_extra_refcount(struct page_state *ps, struct page *p, 
	int count = page_count(p) - 1;



	if (extra_pins)

		count -= 1;

		count -= folio_nr_pages(page_folio(p));



	if (count > 0) {

		pr_err("%#lx: %s still referenced by %d users\n",