Re: [PATCH] Btrfs: remove unnecessary code of chunk_root assignment in btrfs_read_chunk_tree.

From: Qu Wenruo
Date: Thu Sep 08 2016 - 04:01:35 EST




At 09/05/2016 09:19 AM, Zhao Lei wrote:
> Hi, Sean Fu
>
>> From: Sean Fu [mailto:fxinrong@xxxxxxxxx]
>> Sent: Sunday, September 04, 2016 7:54 PM
>> To: dsterba@xxxxxxxx
>> Cc: clm@xxxxxx; anand.jain@xxxxxxxxxx; fdmanana@xxxxxxxx;
>> zhaolei@xxxxxxxxxxxxxx; linux-btrfs@xxxxxxxxxxxxxxx;
>> linux-kernel@xxxxxxxxxxxxxxx; Sean Fu <fxinrong@xxxxxxxxx>
>> Subject: [PATCH] Btrfs: remove unnecessary code of chunk_root assignment in
>> btrfs_read_chunk_tree.
>>
>> The input argument root is already set with "fs_info->chunk_root".
>> "chunk_root = fs_info->chunk_root = btrfs_alloc_root(fs_info)" in caller
>> "open_ctree".
>> âroot->fs_info = fs_infoâ in "btrfs_alloc_root".
>>
> The root argument of this function means "any root".
> And the function is designed getting chunk root from
> "any root" in head.
>
> Since there is only one caller of this function,
> and the caller always send chunk_root as root argument in
> current code, we can remove above conversion,
> and I suggest renaming root to chunk_root to make it clear,
> something like:
>
> - btrfs_read_chunk_tree(struct btrfs_root *root)
> + btrfs_read_chunk_tree(struct btrfs_root *chunk_root)

Since root is only used to get fs_info->chunk_root, why not use fs_info
directly?

Thanks,
Qu

>
> Thanks
> Zhaolei
>
>> Signed-off-by: Sean Fu <fxinrong@xxxxxxxxx>
>> ---
>> fs/btrfs/volumes.c | 2 --
>> 1 file changed, 2 deletions(-)
>>
>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
>> index 366b335..384a6d2 100644
>> --- a/fs/btrfs/volumes.c
>> +++ b/fs/btrfs/volumes.c
>> @@ -6600,8 +6600,6 @@ int btrfs_read_chunk_tree(struct btrfs_root *root)
>> int ret;
>> int slot;
>>
>> - root = root->fs_info->chunk_root;
>> -
>> path = btrfs_alloc_path();
>> if (!path)
>> return -ENOMEM;
>> --
>> 2.6.2
>>
>
>
>
>
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