Re: [PATCH] fs/ext4/super.c: Let 'counters' switched by SMP

[Chen Gang <gang.chen.5i5j@gmail.com>]

On 07/15/2014 05:31 PM, Theodore Ts'o wrote:
> On Tue, Jul 15, 2014 at 09:05:29AM +0800, Chen Gang wrote:
>> When SMP is disabled, 'struct percpu_counter' has no 'counters' member,
>> so need skip it when in !SMP.
>>
>> The related git commit:
>>
>>   "feab139 ext4: rearrange initialization to fix EXT4FS_DEBUG".
>>
>> The related error (with allmodconfig under score):
>>
>>     CC [M]  fs/ext4/super.o
>>   fs/ext4/super.c: In function 'ext4_commit_super':
>>   fs/ext4/super.c:4546:41: error: 'struct percpu_counter' has no member named 'counters'
>>     if (EXT4_SB(sb)->s_freeclusters_counter.counters)
>>                                            ^
>>   fs/ext4/super.c:4550:39: error: 'struct percpu_counter' has no member named 'counters'
>>     if (EXT4_SB(sb)->s_freeinodes_counter.counters)
> 
> Thanks for the pointing out the problem.  I though think the right way
> of fixing this problem, though, instead of using the #ifdef
> CONFIG_SMP, is to do this:
> 
>        if (percpu_counter_initialized(&EXT4_SB(sb)->s_freeclusters_counter))
>        	  ...
> 

That sounds fine to me (unlike my ugly fix, your fix is common and
standard), thanks.

> I'll respin the "ext4: rearrange initialization to fix EXT4FS_DEBUG"
> commit to include this fix and give you credit in the commit logs for
> pointing out this issue.
> 

Thank you for your work.


Thanks.
-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed