The patch titled
Subject: mm/memory-failure.c: fix race with changing page more robustly
has been added to the -mm tree. Its filename is
mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch
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------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/memory-failure.c: fix race with changing page more robustly
We're only intended to deal with the non-Compound page after we split thp
in memory_failure. However, the page could have changed compound pages
due to race window. If this happens, we could retry once to hopefully
handle the page next round. Also remove unneeded orig_head. It's always
equal to the hpage. So we can use hpage directly and remove this
redundant one.
Link: https://lkml.kernel.org/r/20220218090118.1105-5-linmiaohe@xxxxxxxxxx
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
--- a/mm/memory-failure.c~mm-memory-failurec-fix-race-with-changing-page-more-robustly
+++ a/mm/memory-failure.c
@@ -1686,7 +1686,6 @@ int memory_failure(unsigned long pfn, in
{
struct page *p;
struct page *hpage;
- struct page *orig_head;
struct dev_pagemap *pgmap;
int res = 0;
unsigned long page_flags;
@@ -1732,7 +1731,7 @@ try_again:
goto unlock_mutex;
}
- orig_head = hpage = compound_head(p);
+ hpage = compound_head(p);
num_poisoned_pages_inc();
/*
@@ -1813,10 +1812,21 @@ try_again:
lock_page(p);
/*
- * The page could have changed compound pages during the locking.
- * If this happens just bail out.
+ * We're only intended to deal with the non-Compound page here.
+ * However, the page could have changed compound pages due to
+ * race window. If this happens, we could try again to hopefully
+ * handle the page next round.
*/
- if (PageCompound(p) && compound_head(p) != orig_head) {
+ if (PageCompound(p)) {
+ if (retry) {
+ if (TestClearPageHWPoison(p))
+ num_poisoned_pages_dec();
+ unlock_page(p);
+ put_page(p);
+ flags &= ~MF_COUNT_INCREASED;
+ retry = false;
+ goto try_again;
+ }
action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED);
res = -EBUSY;
goto unlock_page;
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-memremap-avoid-calling-kasan_remove_zero_shadow-for-device-private-memory.patch
filemap-remove-find_get_pages.patch
mm-use-helper-function-range_in_vma.patch
mm-sparse-make-mminit_validate_memmodel_limits-static.patch
mm-vmalloc-remove-unneeded-function-forward-declaration.patch
mm-mmzoneh-remove-unused-macros.patch
mm-memory-failurec-minor-clean-up-for-memory_failure_dev_pagemap.patch
mm-memory-failurec-catch-unexpected-efault-from-vma_address.patch
mm-memory-failurec-rework-the-signaling-logic-in-kill_proc.patch
mm-memory-failurec-fix-race-with-changing-page-more-robustly.patch
mm-memory-failurec-remove-pageslab-check-in-hwpoison_filter_dev.patch
mm-memory-failurec-rework-the-try_to_unmap-logic-in-hwpoison_user_mappings.patch
mm-memory-failurec-remove-obsolete-comment-in-__soft_offline_page.patch
mm-memory-failurec-remove-unnecessary-pagetranstail-check.patch
mm-hwpoison-inject-support-injecting-hwpoison-to-free-page.patch
mm-ksm-use-helper-macro-__attr_rw.patch
mm-balloon_compaction-make-balloon-page-compaction-callbacks-static.patch
mm-memory_hotplug-remove-obsolete-comment-of-__add_pages.patch
mm-memory_hotplug-avoid-calling-zone_intersects-for-zone_normal.patch
mm-memory_hotplug-clean-up-try_offline_node.patch
mm-memory_hotplug-fix-misplaced-comment-in-offline_pages.patch
mm-highmem-remove-unnecessary-done-label.patch
mm-hmmc-remove-unneeded-local-variable-ret.patch
