[Devel] [PATCH] fs/fuse kio: skip iostat count for unknown req types

[Kirill Tkhai]

On 03.06.2019 09:41, Pavel Butsykin wrote:
> 
> 
> On 31.05.2019 19:06, Kirill Tkhai wrote:
>> On 31.05.2019 12:23, Pavel Butsykin wrote:
>>> There are still some number of response req types:
>>> PCS_CS_WRITE_ZERO_RESP
>>> PCS_CS_WRITE_HOLE_RESP
>>> PCS_CS_REPLICATEX_RESP
>>> PCS_CS_FIEMAP_RESP
>>> PCS_CS_MAP_PROP_RESP
>>>
>>> It makes no sense to count statistics for such requests, so for them the stat
>>> count will simply be skipped.
>>>
>>> Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>
>>> ---
>>>   fs/fuse/kio/pcs/fuse_stat.c | 7 ++++---
>>>   1 file changed, 4 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/fs/fuse/kio/pcs/fuse_stat.c b/fs/fuse/kio/pcs/fuse_stat.c
>>> index 06be3c75240c..31ff73d6c3dc 100644
>>> --- a/fs/fuse/kio/pcs/fuse_stat.c
>>> +++ b/fs/fuse/kio/pcs/fuse_stat.c
>>> @@ -654,7 +654,6 @@ struct fuse_val_stat *req_stat_entry(struct pcs_fuse_io_stat *io, u32 type)
>>>   		default:
>>>   			break;
>>>   	}
>>> -	WARN_ON_ONCE(1);
>>>   	return NULL;
>>>   }
>>>   
>>> @@ -663,9 +662,11 @@ static void fuse_iostat_count(struct pcs_fuse_io_stat_sync *iostat,
>>>   {
>>>   	struct fuse_val_stat *se;
>>>   
>>> -	write_seqlock(&iostat->seqlock);
>>>   	se = req_stat_entry(iostat->CURR(iostat), type);
>>
>> Shouldn't iostat->CURR(iostat) be obtained under seqlock?
>>
> 
> Yep, iostat->CURR(iostat) should be under seqlock, thanks for fixup!

I think it may be useful to add some lockdep check into CURR and other macros.

Kirill