+ mmhwpoison-inject-dont-pin-for-hwpoison_filter.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: mm,hwpoison-inject: don't pin for hwpoison_filter
has been added to the -mm tree.  Its filename is
     mmhwpoison-inject-dont-pin-for-hwpoison_filter.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mmhwpoison-inject-dont-pin-for-hwpoison_filter.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mmhwpoison-inject-dont-pin-for-hwpoison_filter.patch

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------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Subject: mm,hwpoison-inject: don't pin for hwpoison_filter

Another memory error injection interface debugfs:hwpoison/corrupt-pfn also
takes bogus refcount for hwpoison_filter().  It's justified because this
does a coarse filter, expecting that memory_failure() redoes the check for
sure.

Link: https://lkml.kernel.org/r/20200922135650.1634-4-osalvador@suse.de
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Aristeu Rozanski <aris@ruivo.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Yakunin <zeil@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/hwpoison-inject.c |   18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

--- a/mm/hwpoison-inject.c~mmhwpoison-inject-dont-pin-for-hwpoison_filter
+++ a/mm/hwpoison-inject.c
@@ -26,11 +26,6 @@ static int hwpoison_inject(void *data, u
 
 	p = pfn_to_page(pfn);
 	hpage = compound_head(p);
-	/*
-	 * This implies unable to support free buddy pages.
-	 */
-	if (!get_hwpoison_page(p))
-		return 0;
 
 	if (!hwpoison_filter_enable)
 		goto inject;
@@ -40,23 +35,20 @@ static int hwpoison_inject(void *data, u
 	 * This implies unable to support non-LRU pages.
 	 */
 	if (!PageLRU(hpage) && !PageHuge(p))
-		goto put_out;
+		return 0;
 
 	/*
-	 * do a racy check with elevated page count, to make sure PG_hwpoison
-	 * will only be set for the targeted owner (or on a free page).
+	 * do a racy check to make sure PG_hwpoison will only be set for
+	 * the targeted owner (or on a free page).
 	 * memory_failure() will redo the check reliably inside page lock.
 	 */
 	err = hwpoison_filter(hpage);
 	if (err)
-		goto put_out;
+		return 0;
 
 inject:
 	pr_info("Injecting memory failure at pfn %#lx\n", pfn);
-	return memory_failure(pfn, MF_COUNT_INCREASED);
-put_out:
-	put_hwpoison_page(p);
-	return 0;
+	return memory_failure(pfn, 0);
 }
 
 static int hwpoison_unpoison(void *data, u64 val)
_

Patches currently in -mm which might be from naoya.horiguchi@nec.com are

mmhwpoison-cleanup-unused-pagehuge-check.patch
mm-hwpoison-remove-recalculating-hpage.patch
mmhwpoison-inject-dont-pin-for-hwpoison_filter.patch
mmhwpoison-introduce-mf_msg_unsplit_thp.patch
mmhwpoison-double-check-page-count-in-__get_any_page.patch