linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Naoya Horiguchi <naoya.horiguchi@linux.dev>
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>,
	Miaohe Lin <linmiaohe@huawei.com>, Yang Shi <shy828301@gmail.com>,
	Peter Xu <peterx@redhat.com>,
	Naoya Horiguchi <naoya.horiguchi@nec.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/4] mm/hwpoison: mf_mutex for soft offline and unpoison
Date: Tue, 26 Oct 2021 08:05:00 +0900	[thread overview]
Message-ID: <20211025230503.2650970-2-naoya.horiguchi@linux.dev> (raw)
In-Reply-To: <20211025230503.2650970-1-naoya.horiguchi@linux.dev>

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>
---
ChangeLog v2:
- add mutex_unlock() in "page already poisoned" path in soft_offline_page().
  (Thanks to Ding Hui)
---
 mm/memory-failure.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index fa9dda95a2a2..97297edfbd8e 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1628,6 +1628,8 @@ 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
@@ -1654,7 +1656,6 @@ 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);
@@ -1978,6 +1979,7 @@ 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);
@@ -1988,28 +1990,30 @@ 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;
 	}
 
 	/*
@@ -2020,7 +2024,7 @@ 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)) {
@@ -2028,7 +2032,7 @@ 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);
@@ -2050,7 +2054,9 @@ 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);
 
@@ -2231,9 +2237,12 @@ 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);
+		mutex_unlock(&mf_mutex);
 		return 0;
 	}
 
@@ -2251,5 +2260,7 @@ int soft_offline_page(unsigned long pfn, int flags)
 		}
 	}
 
+	mutex_unlock(&mf_mutex);
+
 	return ret;
 }
-- 
2.25.1



  reply	other threads:[~2021-10-25 23:06 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-25 23:04 [PATCH v2 0/4] mm/hwpoison: fix unpoison_memory() Naoya Horiguchi
2021-10-25 23:05 ` Naoya Horiguchi [this message]
2021-10-27  1:32   ` [PATCH v2 1/4] mm/hwpoison: mf_mutex for soft offline and unpoison Yang Shi
2021-10-27  2:31     ` Naoya Horiguchi
2021-10-25 23:05 ` [PATCH v2 2/4] mm/hwpoison: remove race consideration Naoya Horiguchi
2021-10-27  1:04   ` Yang Shi
2021-10-27  1:18     ` Naoya Horiguchi
2021-10-25 23:14 ` [PATCH 3/4] mm/hwpoison: remove MF_MSG_BUDDY_2ND and MF_MSG_POISONED_HUGE Naoya Horiguchi
2021-10-27  1:05   ` Yang Shi
2021-10-25 23:16 ` [PATCH v2 4/4] mm/hwpoison: fix unpoison_memory() Naoya Horiguchi
2021-10-25 23:27   ` [PATCH RESEND " Naoya Horiguchi
2021-10-27  1:26     ` Ding Hui
2021-10-27  2:29       ` Naoya Horiguchi
2021-10-27  4:00   ` [PATCH " Yang Shi
2021-10-27 11:58     ` Naoya Horiguchi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211025230503.2650970-2-naoya.horiguchi@linux.dev \
    --to=naoya.horiguchi@linux.dev \
    --cc=akpm@linux-foundation.org \
    --cc=aneesh.kumar@linux.vnet.ibm.com \
    --cc=david@redhat.com \
    --cc=dinghui@sangfor.com.cn \
    --cc=linmiaohe@huawei.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    --cc=naoya.horiguchi@nec.com \
    --cc=osalvador@suse.de \
    --cc=peterx@redhat.com \
    --cc=shy828301@gmail.com \
    --cc=tony.luck@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).