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Date:   Tue, 3 Nov 2020 17:39:21 +0000
From:   Christoph Hellwig <hch@infradead.org>
To:     "Darrick J. Wong" <darrick.wong@oracle.com>
Cc:     xfs <linux-xfs@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Dave Chinner <david@fromorbit.com>, fdmanana@kernel.org
Subject: Re: [RFC PATCH] vfs: remove lockdep bogosity in __sb_start_write
Message-ID: <20201103173921.GA32219@infradead.org>
References: <20201103173300.GF7123@magnolia>
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>  int __sb_start_write(struct super_block *sb, int level, bool wait)
>  {
> -	int ret = 1;
> +	if (!wait)
> +		return percpu_down_read_trylock(sb->s_writers.rw_sem + level-1);
>  
> +	percpu_down_read(sb->s_writers.rw_sem + level-1);
> +	return 1;
>  }
>  EXPORT_SYMBOL(__sb_start_write);

Please split the function into __sb_start_write and
__sb_start_write_trylock while you're at it..