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From:   Zhang Yi <yi.zhang@huawei.com>
To:     <linux-ext4@vger.kernel.org>
CC:     <tytso@mit.edu>, <adilger.kernel@dilger.ca>, <jack@suse.cz>,
        <yi.zhang@huawei.com>, <yukuai3@huawei.com>
Subject: [PATCH 2/2] ext4: correct the cache_nr in tracepoint ext4_es_shrink_exit
Date:   Sat, 22 May 2021 18:30:45 +0800
Message-ID: <20210522103045.690103-3-yi.zhang@huawei.com>
In-Reply-To: <20210522103045.690103-1-yi.zhang@huawei.com>
References: <20210522103045.690103-1-yi.zhang@huawei.com>
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The cache_cnt parameter of tracepoint ext4_es_shrink_exit means the
remaining cache count after shrink, but now it is the cache count before
shrink, fix it by read sbi->s_extent_cache_cnt again.

Fixes: 1ab6c4997e04 ("fs: convert fs shrinkers to new scan/count API")
Cc: stable@vger.kernel.org # 3.12+
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
---
 fs/ext4/extents_status.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index db3cd70a72e4..9a3a8996aacf 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -1576,6 +1576,7 @@ static unsigned long ext4_es_scan(struct shrinker *shrink,
 
 	nr_shrunk = __es_shrink(sbi, nr_to_scan, NULL);
 
+	ret = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt);
 	trace_ext4_es_shrink_scan_exit(sbi->s_sb, nr_shrunk, ret);
 	return nr_shrunk;
 }
-- 
2.25.4