Re: [PATCH 2/2] Btrfs-progs: use bitfield instead of integer for some variants in fs_info

[Wang Shilong <wangsl.fnst@cn.fujitsu.com>]

On 02/26/2014 12:28 AM, David Sterba wrote:
> On Tue, Feb 25, 2014 at 07:48:57PM +0800, Wang Shilong wrote:
>> Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
>> ---
>>   ctree.h | 8 +++++---
>>   1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/ctree.h b/ctree.h
>> index 3cc3477..9b461af 100644
>> --- a/ctree.h
>> +++ b/ctree.h
>> @@ -984,9 +984,11 @@ struct btrfs_fs_info {
>>   	struct btrfs_fs_devices *fs_devices;
>>   	struct list_head space_info;
>>   	int system_allocs;
>> -	int readonly;
>> -	int on_restoring;
>> -	int is_chunk_recover;
>> +
>> +	unsigned int readonly:1;
>> +	unsigned int on_restoring:1;
>> +	unsigned int is_chunk_recover:1;
> Well, the integers are wasteful, but there's only one instance of
> fs_info per fsck run, so it saves like 8 bytes in total. I'm not sure
> this patch is needed.
Originally, i wrote this patch, it is because i was going to add a new flag.
However, that approach has been replaced by a better idea.

Anyway, this patch will be a good start, however, i don't insist on it.
We can also change it  when we have to add another flag later.

David, just do what you like here.

Thanks,
Wang
>