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Subject: [PATCH v2] f2fs: fix uninitialized skipped_gc_rwsem
Reply-To: yonggil.song@samsung.com
Sender: Yonggil Song <yonggil.song@samsung.com>
From:   Yonggil Song <yonggil.song@samsung.com>
To:     Chao Yu <chao@kernel.org>,
        "jaegeuk@kernel.org" <jaegeuk@kernel.org>,
        "linux-f2fs-devel@lists.sourceforge.net" 
        <linux-f2fs-devel@lists.sourceforge.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "daehojeong@google.com" <daehojeong@google.com>
CC:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        Seokhwan Kim <sukka.kim@samsung.com>,
        Daejun Park <daejun7.park@samsung.com>
Message-ID: <20230216072821epcms2p35e1fecca382380723ac0031862687173@epcms2p3>
Date:   Thu, 16 Feb 2023 16:28:21 +0900
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References: <CGME20230215024850epcms2p22be2cc864d82b44f31c19a7ef28770b6@epcms2p3>
Precedence: bulk

When f2fs skipped a gc round during victim migration, there was a bug which
would skip all upcoming gc rounds unconditionally because skipped_gc_rwsem
was not initialized. It fixes the bug by correctly initializing the
skipped_gc_rwsem inside the gc loop.

Fixes: 3db1de0e582c ("f2fs: change the current atomic write way")
Signed-off-by: Yonggil Song <yonggil.song@samsung.com>

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index b22f49a6f128..81d326abaac1 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -1786,8 +1786,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
 				prefree_segments(sbi));
 
 	cpc.reason = __get_cp_reason(sbi);
-	sbi->skipped_gc_rwsem = 0;
 gc_more:
+	sbi->skipped_gc_rwsem = 0;
 	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
 		ret = -EINVAL;
 		goto stop;
-- 
2.34.1