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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2024-03-21 14:24:39 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-11-17 15:08:59 +0100 |
| commit | 0275e4021b0c8f0e81d8f32756bd76f9c188eadd (patch) | |
| tree | c7f796ef76111bfb124f3a796f188768ef6e3831 /mm/page_alloc.c | |
| parent | e8769509d622b41af8080d35c766f59d4aae326c (diff) | |
| download | linux-0275e4021b0c8f0e81d8f32756bd76f9c188eadd.tar.gz linux-0275e4021b0c8f0e81d8f32756bd76f9c188eadd.tar.bz2 linux-0275e4021b0c8f0e81d8f32756bd76f9c188eadd.zip | |
mm: always initialise folio->_deferred_list
commit b7b098cf00a2b65d5654a86dc8edf82f125289c1 upstream.
Patch series "Various significant MM patches".
These patches all interact in annoying ways which make it tricky to send
them out in any way other than a big batch, even though there's not really
an overarching theme to connect them.
The big effects of this patch series are:
- folio_test_hugetlb() becomes reliable, even when called without a
page reference
- We free up PG_slab, and we could always use more page flags
- We no longer need to check PageSlab before calling page_mapcount()
This patch (of 9):
For compound pages which are at least order-2 (and hence have a
deferred_list), initialise it and then we can check at free that the page
is not part of a deferred list. We recently found this useful to rule out
a source of corruption.
[peterx@redhat.com: always initialise folio->_deferred_list]
Link: https://lkml.kernel.org/r/20240417211836.2742593-2-peterx@redhat.com
Link: https://lkml.kernel.org/r/20240321142448.1645400-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240321142448.1645400-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Include three small changes from the upstream commit, for backport safety:
replace list_del() by list_del_init() in split_huge_page_to_list(),
like c010d47f107f ("mm: thp: split huge page to any lower order pages");
replace list_del() by list_del_init() in folio_undo_large_rmappable(), like
9bcef5973e31 ("mm: memcg: fix split queue list crash when large folio migration");
keep __free_pages() instead of folio_put() in __update_and_free_hugetlb_folio(). ]
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 959383d8d74d..6ffd6255608e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1002,10 +1002,11 @@ static int free_tail_page_prepare(struct page *head_page, struct page *page) } break; case 2: - /* - * the second tail page: ->mapping is - * deferred_list.next -- ignore value. - */ + /* the second tail page: deferred_list overlaps ->mapping */ + if (unlikely(!list_empty(&folio->_deferred_list))) { + bad_page(page, "on deferred list"); + goto out; + } break; default: if (page->mapping != TAIL_MAPPING) { |