From: Jaegeuk Kim <jaegeuk@kernel.org>
To: linux-kernel@vger.kernel.org,
linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com
Cc: Jaegeuk Kim <jaegeuk@kernel.org>, Light Hsieh <Light.Hsieh@mediatek.com>
Subject: [PATCH] f2fs: avoid race condition for shinker count
Date: Mon, 9 Nov 2020 09:00:12 -0800 [thread overview]
Message-ID: <20201109170012.2129411-1-jaegeuk@kernel.org> (raw)
Light reported sometimes shinker gets nat_cnt < dirty_nat_cnt resulting in
wrong do_shinker work. Basically the two counts should not happen like that.
So, I suspect this race condtion where:
- f2fs_try_to_free_nats __flush_nat_entry_set
nat_cnt=2, dirty_nat_cnt=2
__clear_nat_cache_dirty
spin_lock(nat_list_lock)
list_move()
spin_unlock(nat_list_lock)
spin_lock(nat_list_lock)
list_del()
spin_unlock(nat_list_lock)
nat_cnt=1, dirty_nat_cnt=2
nat_cnt=1, dirty_nat_cnt=1
Reported-by: Light Hsieh <Light.Hsieh@mediatek.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/node.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 42394de6c7eb..e8ec65e40f06 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -269,11 +269,10 @@ static void __clear_nat_cache_dirty(struct f2fs_nm_info *nm_i,
{
spin_lock(&nm_i->nat_list_lock);
list_move_tail(&ne->list, &nm_i->nat_entries);
- spin_unlock(&nm_i->nat_list_lock);
-
set_nat_flag(ne, IS_DIRTY, false);
set->entry_cnt--;
nm_i->dirty_nat_cnt--;
+ spin_unlock(&nm_i->nat_list_lock);
}
static unsigned int __gang_lookup_nat_set(struct f2fs_nm_info *nm_i,
--
2.29.2.222.g5d2a92d10f8-goog
next reply other threads:[~2020-11-09 17:00 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-09 17:00 Jaegeuk Kim [this message]
2020-11-10 2:15 ` [f2fs-dev] [PATCH] f2fs: avoid race condition for shinker count Chao Yu
2020-11-10 4:19 ` Jaegeuk Kim
2020-11-10 6:04 ` Chao Yu
2020-11-12 5:31 ` Jaegeuk Kim
2020-11-12 5:34 ` [PATCH v2] " Jaegeuk Kim
2020-11-12 5:40 ` [f2fs-dev] [PATCH v3] " Jaegeuk Kim
2020-11-12 6:57 ` Chao Yu
2020-11-17 16:40 ` Jaegeuk Kim
2020-12-03 6:07 ` Jaegeuk Kim
2020-12-03 6:55 ` Chao Yu
2020-12-03 7:55 ` Jaegeuk Kim
2020-12-03 8:16 ` Chao Yu
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