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Date:   Mon, 9 Nov 2020 12:07:05 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Alex Shi <alex.shi@linux.alibaba.com>
Cc:     linmiaohe@huawei.com, akpm@linux-foundation.org,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        Hugh Dickins <hughd@google.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [REF PATCH] mm/swap: fix swapon failure
Message-ID: <20201109120705.GZ17076@casper.infradead.org>
References: <1604922436-16597-1-git-send-email-alex.shi@linux.alibaba.com>
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On Mon, Nov 09, 2020 at 07:47:16PM +0800, Alex Shi wrote:
> Go through the context I found the exit_swap_address_space(p->type)
> shouldn't be used in good result path. So just move it to error path.

But ... it's not used in the success path.  There's a 'goto' right
before it.  Does this really fix your problem?

> @@ -3339,7 +3339,8 @@ static bool swap_discardable(struct swap_info_struct *si)
>  	error = inode_drain_writes(inode);
>  	if (error) {
>  		inode->i_flags &= ~S_SWAPFILE;
> -		goto free_swap_address_space;
> +		exit_swap_address_space(p->type);
> +		goto bad_swap_unlock_inode;
>  	}
>  
>  	mutex_lock(&swapon_mutex);
> @@ -3364,8 +3365,6 @@ static bool swap_discardable(struct swap_info_struct *si)
>  
>  	error = 0;
>  	goto out;
> -free_swap_address_space:
> -	exit_swap_address_space(p->type);
>  bad_swap_unlock_inode:
>  	inode_unlock(inode);
>  bad_swap:
> -- 
> 1.8.3.1
> 
>