[PATCH] fs: btrfs: remove the usage of undeclared fs_mutex variable

[Qu Wenruo]

On 2022/9/27 18:39, Qu Wenruo wrote:
> 
> 
> On 2022/9/27 17:55, Pankaj Raghav wrote:
>> This line probably got in by mistake as there is no fs_mutex member in
>> the btrfs_fs_info struct.
>>
>> Signed-off-by: Pankaj Raghav <p.raghav at samsung.com>
> 
> Which branch is the code based on?
> 
> I don't believe it's upstream, as such compiling error should be exposed 
> very easily.
> 
>> ---
>>   fs/btrfs/disk-io.c | 2 --
>>   1 file changed, 2 deletions(-)
>>
>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> 
> Furthermore at current upstream HEAD a1375562c0a8 ("Merge tag 
> 'x86_urgent_for_v6.0-rc8' of 
> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip"), there is no 
> btrfs_new_fs_info() function defined anyway.

My bad, I didn't notice it's for Uboot, not kernel.

In that case, you can safely remove it, but it won't cause compile error 
since in <linux/compat.h>, we define mutex_init() as noop, thus it 
doesn't cause any compile error.

Anyway the patch itself looks good, I also checked if there is other 
mutex related usage, and this is the only one.

Reviewed-by: Qu Wenruo <wqu at suse.com>

Thanks,
Qu

> 
> THanks,
> Qu
> 
>> index 8043abc1bd..c80f8e8028 100644
>> --- a/fs/btrfs/disk-io.c
>> +++ b/fs/btrfs/disk-io.c
>> @@ -782,8 +782,6 @@ struct btrfs_fs_info *btrfs_new_fs_info(void)
>>       fs_info->fs_root_tree = RB_ROOT;
>>       cache_tree_init(&fs_info->mapping_tree.cache_tree);
>> -    mutex_init(&fs_info->fs_mutex);
>> -
>>       return fs_info;
>>   free_all:
>>       btrfs_free_fs_info(fs_info);