[merged mm-stable] mm-hwpoison-kill-procs-if-unmap-fails.patch removed from -mm tree

[merged mm-stable] mm-hwpoison-kill-procs-if-unmap-fails.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm, hwpoison: kill procs if unmap fails
has been removed from the -mm tree.  Its filename was
     mm-hwpoison-kill-procs-if-unmap-fails.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm, hwpoison: kill procs if unmap fails
Date: Thu, 18 Aug 2022 21:00:15 +0800

If try_to_unmap() fails, the hwpoisoned page still resides in the address
space of some processes.  We should kill these processes or the hwpoisoned
page might be consumed later.  collect_procs() is always called to collect
relevant processes now so they can be killed later if unmap fails.

[linmiaohe@huawei.com: v2]
  Link: https://lkml.kernel.org/r/20220823032346.4260-6-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220818130016.45313-6-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memory-failure.c |   12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

--- a/mm/memory-failure.c~mm-hwpoison-kill-procs-if-unmap-fails
+++ a/mm/memory-failure.c
@@ -1397,7 +1397,7 @@ static bool hwpoison_user_mappings(struc
 	struct address_space *mapping;
 	LIST_HEAD(tokill);
 	bool unmap_success;
-	int kill = 1, forcekill;
+	int forcekill;
 	bool mlocked = PageMlocked(hpage);
 
 	/*
@@ -1438,7 +1438,6 @@ static bool hwpoison_user_mappings(struc
 		if (page_mkclean(hpage)) {
 			SetPageDirty(hpage);
 		} else {
-			kill = 0;
 			ttu |= TTU_IGNORE_HWPOISON;
 			pr_info("%#lx: corrupted page was clean: dropped without side effects\n",
 				pfn);
@@ -1449,12 +1448,8 @@ static bool hwpoison_user_mappings(struc
 	 * First collect all the processes that have the page
 	 * mapped in dirty form.  This has to be done before try_to_unmap,
 	 * because ttu takes the rmap data structures down.
-	 *
-	 * Error handling: We ignore errors here because
-	 * there's nothing that can be done.
 	 */
-	if (kill)
-		collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
+	collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
 
 	if (PageHuge(hpage) && !PageAnon(hpage)) {
 		/*
@@ -1496,7 +1491,8 @@ static bool hwpoison_user_mappings(struc
 	 * use a more force-full uncatchable kill to prevent
 	 * any accesses to the poisoned memory.
 	 */
-	forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL);
+	forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL) ||
+		    !unmap_success;
 	kill_procs(&tokill, forcekill, !unmap_success, pfn, flags);
 
 	return unmap_success;
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-hwpoison-use-clearpagehwpoison-in-memory_failure.patch
mm-hwpoison-use-__pagemovable-to-detect-non-lru-movable-pages.patch
mm-hwpoison-use-num_poisoned_pages_sub-to-decrease-num_poisoned_pages.patch
mm-hwpoison-avoid-unneeded-page_mapped_in_vma-overhead-in-collect_procs_anon.patch
mm-hwpoison-check-pagetable-explicitly-in-hwpoison_user_mappings.patch
mm-hwpoison-cleanup-some-obsolete-comments.patch
writeback-remove-unused-macro-dirty_full_scope.patch