From: Naoya Horiguchi <nao.horiguchi@gmail.com>
To: linux-mm@kvack.org
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@redhat.com>,
Oscar Salvador <osalvador@suse.de>,
Michal Hocko <mhocko@suse.com>, Ding Hui <dinghui@sangfor.com.cn>,
Tony Luck <tony.luck@intel.com>,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Naoya Horiguchi <naoya.horiguchi@nec.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH v1 1/6] mm/hwpoison: mf_mutex for soft offline and unpoison
Date: Mon, 14 Jun 2021 11:12:07 +0900 [thread overview]
Message-ID: <20210614021212.223326-2-nao.horiguchi@gmail.com> (raw)
In-Reply-To: <20210614021212.223326-1-nao.horiguchi@gmail.com>
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Originally mf_mutex is introduced to serialize multiple MCE events, but
it's also helpful to exclude races among soft_offline_page() and
unpoison_memory(). So apply mf_mutex to them.
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
---
mm/memory-failure.c | 26 ++++++++++++++++++--------
1 file changed, 18 insertions(+), 8 deletions(-)
diff --git v5.13-rc5/mm/memory-failure.c v5.13-rc5_patched/mm/memory-failure.c
index ae30fd6d575a..280eb6d6dd15 100644
--- v5.13-rc5/mm/memory-failure.c
+++ v5.13-rc5_patched/mm/memory-failure.c
@@ -1583,6 +1583,8 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
return rc;
}
+static DEFINE_MUTEX(mf_mutex);
+
/**
* memory_failure - Handle memory failure of a page.
* @pfn: Page Number of the corrupted page
@@ -1609,7 +1611,6 @@ int memory_failure(unsigned long pfn, int flags)
int res = 0;
unsigned long page_flags;
bool retry = true;
- static DEFINE_MUTEX(mf_mutex);
if (!sysctl_memory_failure_recovery)
panic("Memory failure on page %lx", pfn);
@@ -1918,6 +1919,7 @@ int unpoison_memory(unsigned long pfn)
struct page *page;
struct page *p;
int freeit = 0;
+ int ret = 0;
unsigned long flags = 0;
static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
DEFAULT_RATELIMIT_BURST);
@@ -1928,28 +1930,30 @@ int unpoison_memory(unsigned long pfn)
p = pfn_to_page(pfn);
page = compound_head(p);
+ mutex_lock(&mf_mutex);
+
if (!PageHWPoison(p)) {
unpoison_pr_info("Unpoison: Page was already unpoisoned %#lx\n",
pfn, &unpoison_rs);
- return 0;
+ goto unlock_mutex;
}
if (page_count(page) > 1) {
unpoison_pr_info("Unpoison: Someone grabs the hwpoison page %#lx\n",
pfn, &unpoison_rs);
- return 0;
+ goto unlock_mutex;
}
if (page_mapped(page)) {
unpoison_pr_info("Unpoison: Someone maps the hwpoison page %#lx\n",
pfn, &unpoison_rs);
- return 0;
+ goto unlock_mutex;
}
if (page_mapping(page)) {
unpoison_pr_info("Unpoison: the hwpoison page has non-NULL mapping %#lx\n",
pfn, &unpoison_rs);
- return 0;
+ goto unlock_mutex;
}
/*
@@ -1960,7 +1964,7 @@ int unpoison_memory(unsigned long pfn)
if (!PageHuge(page) && PageTransHuge(page)) {
unpoison_pr_info("Unpoison: Memory failure is now running on %#lx\n",
pfn, &unpoison_rs);
- return 0;
+ goto unlock_mutex;
}
if (!get_hwpoison_page(p, flags)) {
@@ -1968,7 +1972,7 @@ int unpoison_memory(unsigned long pfn)
num_poisoned_pages_dec();
unpoison_pr_info("Unpoison: Software-unpoisoned free page %#lx\n",
pfn, &unpoison_rs);
- return 0;
+ goto unlock_mutex;
}
lock_page(page);
@@ -1990,7 +1994,9 @@ int unpoison_memory(unsigned long pfn)
if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1))
put_page(page);
- return 0;
+unlock_mutex:
+ mutex_unlock(&mf_mutex);
+ return ret;
}
EXPORT_SYMBOL(unpoison_memory);
@@ -2171,6 +2177,8 @@ int soft_offline_page(unsigned long pfn, int flags)
return -EIO;
}
+ mutex_lock(&mf_mutex);
+
if (PageHWPoison(page)) {
pr_info("%s: %#lx page already poisoned\n", __func__, pfn);
put_ref_page(ref_page);
@@ -2194,5 +2202,7 @@ int soft_offline_page(unsigned long pfn, int flags)
__func__, pfn, page->flags, &page->flags);
}
+ mutex_unlock(&mf_mutex);
+
return ret;
}
--
2.25.1
next prev parent reply other threads:[~2021-06-14 2:12 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-14 2:12 [PATCH v1 0/6] mm/hwpoison: fix unpoison_memory() Naoya Horiguchi
2021-06-14 2:12 ` Naoya Horiguchi [this message]
2021-06-15 11:41 ` [PATCH v1 1/6] mm/hwpoison: mf_mutex for soft offline and unpoison Ding Hui
2021-06-14 2:12 ` [PATCH v1 2/6] mm/hwpoison: remove race consideration Naoya Horiguchi
2021-06-15 12:57 ` Ding Hui
[not found] ` <20210616001141.GA1924716@hori.linux.bs1.fc.nec.co.jp>
2021-06-16 0:40 ` Ding Hui
2021-06-14 2:12 ` [PATCH v1 3/6] mm/hwpoison: introduce MF_MSG_PAGETABLE Naoya Horiguchi
2021-06-14 3:06 ` Matthew Wilcox
2021-06-14 2:12 ` [PATCH v1 4/6] mm/hwpoison: remove MF_MSG_BUDDY_2ND and MF_MSG_POISONED_HUGE Naoya Horiguchi
2021-06-14 2:12 ` [PATCH v1 5/6] mm/hwpoison: make some kernel pages handlable Naoya Horiguchi
2021-07-28 10:59 ` Ding Hui
2021-06-14 2:12 ` [PATCH v1 6/6] mm/hwpoison: fix unpoison_memory() Naoya Horiguchi
2021-06-17 10:00 ` Ding Hui
[not found] ` <20210618083625.GA2215283@hori.linux.bs1.fc.nec.co.jp>
2021-06-19 12:22 ` Ding Hui
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