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Subject: Re: [REF PATCH] mm/swap: fix swapon failure
To:     Matthew Wilcox <willy@infradead.org>
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
References: <1604922436-16597-1-git-send-email-alex.shi@linux.alibaba.com>
 <20201109120705.GZ17076@casper.infradead.org>
From:   Alex Shi <alex.shi@linux.alibaba.com>
Message-ID: <88fb2ed0-cb0c-2b4b-a73e-3a64fdc0a2cd@linux.alibaba.com>
Date:   Mon, 9 Nov 2020 20:17:58 +0800
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?? 2020/11/9 ????8:07, Matthew Wilcox д??:
> 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?
> 

The trick thing is. It do fix my problem on my centos 7 with gcc 8.3.1...

I am getting headache on this 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
>>
>>