The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b0ff4fe746fd028eef920ddc8c7b0361c1ede6ec Mon Sep 17 00:00:00 2001

From: Jaegeuk Kim jaegeuk@kernel.org Date: Tue, 26 Jan 2021 17:00:42 -0800 Subject: [PATCH] f2fs: flush data when enabling checkpoint back

During checkpoint=disable period, f2fs bypasses all the synchronous IOs such as sync and fsync. So, when enabling it back, we must flush all of them in order to keep the data persistent. Otherwise, suddern power-cut right after enabling checkpoint will cause data loss.

Fixes: 4354994f097d ("f2fs: checkpoint disabling") Cc: stable@vger.kernel.org Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index fc343243799c..429bc00af440 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1892,6 +1892,9 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi)

static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi) { + /* we should flush all the data to keep data consistency */ + sync_inodes_sb(sbi->sb); + down_write(&sbi->gc_lock); f2fs_dirty_to_prefree(sbi);