Re: [REF PATCH] mm/swap: fix swapon failure

From: Alex Shi
Date: Mon Nov 09 2020 - 07:36:35 EST




在 2020/11/9 下午8:17, Alex Shi 写道:
>
>
> 在 2020/11/9 下午8:07, Matthew Wilcox 写道:
>> 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...

Checked again on my git tree. nothing weird, and code based on
cf7cd542d1b5 Add linux-next specific files for 20201104

Sorry, I have no idea where is the 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
>>>
>>>