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From: nao.horiguchi@gmail.com
To: linux-mm@kvack.org
Cc: mhocko@kernel.org, akpm@linux-foundation.org,
	mike.kravetz@oracle.com, osalvador@suse.de, tony.luck@intel.com,
	david@redhat.com, aneesh.kumar@linux.vnet.ibm.com,
	zeil@yandex-team.ru, cai@lca.pw, naoya.horiguchi@nec.com,
	linux-kernel@vger.kernel.org
Subject: [PATCH v5 05/16] mm,hwpoison-inject: don't pin for hwpoison_filter
Date: Fri, 31 Jul 2020 12:21:01 +0000
Message-ID: <20200731122112.11263-6-nao.horiguchi@gmail.com> (raw)
In-Reply-To: <20200731122112.11263-1-nao.horiguchi@gmail.com>

From: Naoya Horiguchi <naoya.horiguchi@nec.com>

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.

Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Oscar Salvador <osalvador@suse.com>
---
 mm/hwpoison-inject.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git v5.8-rc7-mmotm-2020-07-27-18-18/mm/hwpoison-inject.c v5.8-rc7-mmotm-2020-07-27-18-18_patched/mm/hwpoison-inject.c
index e488876b168a..1ae1ebc2b9b1 100644
--- v5.8-rc7-mmotm-2020-07-27-18-18/mm/hwpoison-inject.c
+++ v5.8-rc7-mmotm-2020-07-27-18-18_patched/mm/hwpoison-inject.c
@@ -26,11 +26,6 @@ static int hwpoison_inject(void *data, u64 val)
 
 	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, u64 val)
 	 * 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)
-- 
2.17.1



  parent reply index

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-31 12:20 [PATCH v5 00/16] HWPOISON: soft offline rework nao.horiguchi
2020-07-31 12:20 ` [PATCH v5 01/16] mm,hwpoison: cleanup unused PageHuge() check nao.horiguchi
2020-07-31 12:20 ` [PATCH v5 02/16] mm, hwpoison: remove recalculating hpage nao.horiguchi
2020-07-31 12:20 ` [PATCH v5 03/16] mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 04/16] mm,madvise: Refactor madvise_inject_error nao.horiguchi
2020-07-31 12:21 ` nao.horiguchi [this message]
2020-07-31 12:21 ` [PATCH v5 06/16] mm,hwpoison: Un-export get_hwpoison_page and make it static nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 07/16] mm,hwpoison: Kill put_hwpoison_page nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 08/16] mm,hwpoison: remove MF_COUNT_INCREASED nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 09/16] mm,hwpoison: remove flag argument from soft offline functions nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 10/16] mm,hwpoison: Unify THP handling for hard and soft offline nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 11/16] mm,hwpoison: Rework soft offline for free pages nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 12/16] mm,hwpoison: Rework soft offline for in-use pages nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 13/16] mm,hwpoison: Refactor soft_offline_huge_page and __soft_offline_page nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 14/16] mm,hwpoison: Return 0 if the page is already poisoned in soft-offline nao.horiguchi
2020-07-31 12:21 ` [PATCH v5 15/16] mm,hwpoison: introduce MF_MSG_UNSPLIT_THP nao.horiguchi
     [not found] ` <20200803123954.GA4631@lca.pw>
2020-08-03 13:36   ` [PATCH v5 00/16] HWPOISON: soft offline rework HORIGUCHI NAOYA(堀口 直也)
     [not found]     ` <20200803151907.GA8894@lca.pw>
2020-08-05 20:43       ` HORIGUCHI NAOYA(堀口 直也)
     [not found] ` <20200803190709.GB8894@lca.pw>
2020-08-04  1:16   ` HORIGUCHI NAOYA(堀口 直也)
2020-08-04  1:49     ` Qian Cai
2020-08-04  8:13       ` osalvador
2020-08-05 20:44       ` HORIGUCHI NAOYA(堀口 直也)

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