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From: Jaegeuk Kim <jaegeuk@kernel.org>
To: linux-kernel@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com
Cc: Light Hsieh <Light.Hsieh@mediatek.com>
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: avoid race condition for shinker count
Date: Wed, 11 Nov 2020 21:34:14 -0800	[thread overview]
Message-ID: <20201112053414.GB3826485@google.com> (raw)
In-Reply-To: <20201109170012.2129411-1-jaegeuk@kernel.org>

Light reported sometimes shinker gets nat_cnt < dirty_nat_cnt resulting in
wrong do_shinker work. Let's avoid to get stale data by using nat_tree_lock.

Reported-by: Light Hsieh <Light.Hsieh@mediatek.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/shrinker.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index d66de5999a26..d42245ab07f4 100644
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -18,7 +18,11 @@ static unsigned int shrinker_run_no;
 
 static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
 {
-	long count = NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
+	long count;
+
+	down_read(&nm_i->nat_tree_lock);
+	count = NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
+	up_read(&nm_i->nat_tree_lock);
 
 	return count > 0 ? count : 0;
 }
-- 
2.29.2.299.gdc1121823c-goog



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Linux-f2fs-devel@lists.sourceforge.net
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WARNING: multiple messages have this Message-ID (diff)
From: Jaegeuk Kim <jaegeuk@kernel.org>
To: linux-kernel@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com
Cc: Light Hsieh <Light.Hsieh@mediatek.com>
Subject: Re: [PATCH v2] f2fs: avoid race condition for shinker count
Date: Wed, 11 Nov 2020 21:34:14 -0800	[thread overview]
Message-ID: <20201112053414.GB3826485@google.com> (raw)
In-Reply-To: <20201109170012.2129411-1-jaegeuk@kernel.org>

Light reported sometimes shinker gets nat_cnt < dirty_nat_cnt resulting in
wrong do_shinker work. Let's avoid to get stale data by using nat_tree_lock.

Reported-by: Light Hsieh <Light.Hsieh@mediatek.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/shrinker.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index d66de5999a26..d42245ab07f4 100644
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -18,7 +18,11 @@ static unsigned int shrinker_run_no;
 
 static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
 {
-	long count = NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
+	long count;
+
+	down_read(&nm_i->nat_tree_lock);
+	count = NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
+	up_read(&nm_i->nat_tree_lock);
 
 	return count > 0 ? count : 0;
 }
-- 
2.29.2.299.gdc1121823c-goog


  parent reply	other threads:[~2020-11-12  5:34 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-09 17:00 [f2fs-dev] [PATCH] f2fs: avoid race condition for shinker count Jaegeuk Kim
2020-11-09 17:00 ` Jaegeuk Kim
2020-11-10  2:15 ` [f2fs-dev] " Chao Yu
2020-11-10  2:15   ` Chao Yu
2020-11-10  4:19   ` Jaegeuk Kim
2020-11-10  4:19     ` Jaegeuk Kim
2020-11-10  6:04     ` Chao Yu
2020-11-10  6:04       ` Chao Yu
2020-11-12  5:31       ` Jaegeuk Kim
2020-11-12  5:31         ` Jaegeuk Kim
2020-11-12  5:34 ` Jaegeuk Kim [this message]
2020-11-12  5:34   ` [PATCH v2] " Jaegeuk Kim
2020-11-12  5:40   ` [f2fs-dev] [PATCH v3] " Jaegeuk Kim
2020-11-12  5:40     ` Jaegeuk Kim
2020-11-12  6:57     ` Chao Yu
2020-11-12  6:57       ` Chao Yu
2020-11-17 16:40       ` Jaegeuk Kim
2020-11-17 16:40         ` Jaegeuk Kim
2020-12-03  6:07     ` Jaegeuk Kim
2020-12-03  6:07       ` Jaegeuk Kim
2020-12-03  6:55       ` Chao Yu
2020-12-03  6:55         ` Chao Yu
2020-12-03  7:55         ` Jaegeuk Kim
2020-12-03  7:55           ` Jaegeuk Kim
2020-12-03  8:16           ` Chao Yu
2020-12-03  8:16             ` Chao Yu

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