Re: [PATCH 1/4] vfio: ccw: fix cleanup if cp_prefetch fails

[Halil Pasic <pasic@linux.vnet.ibm.com>]

ping

I think get this fixed. Better sooner than later.

On 03/27/2018 03:42 AM, Dong Jia Shi wrote:
> * Cornelia Huck <cohuck@redhat.com> [2018-03-26 14:28:39 +0200]:
> 
> [...]
> 
>>> By the way, since you will propose a new version,
>>> you have a long description of the cp_prefetch function in the code.
>>> I think you should modify it according to the changes and describe how and
>>> why the ch_len field of each chain is used and changed by this function.
>>>
>>> Something like:
>>>
>>> "
>>> For each chain composing the channel program:
>>> On entry ch_len hold the count of CCW to be translated.
>>
>> s/hold/holds/ ?
>>
> Sure.
> 
>>> On exit ch_len is adjusted to the count of successfully translated CCW.
>>>
>>> This allows cp_free to find in ch_len the count of CCW to free in a chain.
>>> "
>>>
>>> Could also be inside the commit message.
>>>
>>> Pierre
>>>
>>>
>>>>   
>>>>>> Acked-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
>>>>>> Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
>>>>>> Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
>>>>>> Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
>>>>>> ---
>>>>>>    drivers/s390/cio/vfio_ccw_cp.c | 9 ++++++++-
>>>>>>    1 file changed, 8 insertions(+), 1 deletion(-)
>>>>>>
>>>>>> diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
>>>>>> index d9a2fffd034b..2be114db02f9 100644
>>>>>> --- a/drivers/s390/cio/vfio_ccw_cp.c
>>>>>> +++ b/drivers/s390/cio/vfio_ccw_cp.c
>>>>>> @@ -749,11 +749,18 @@ int cp_prefetch(struct channel_program *cp)
>>>>>>    		for (idx = 0; idx < len; idx++) {
>>>>>>    			ret = ccwchain_fetch_one(chain, idx, cp);
>>>>>>    			if (ret)
>>>>>> -				return ret;
>>>>>> +				goto out_err;
>>>>>>    		}
>>>>>>    	}
>>>>>>
>>>>>>    	return 0;
>>>>>> +out_err:
>>>>>> +	/* Only cleanup the chain elements that where actually translated. */
>>
>> s/where/were/
> Ok.
> 
>>
>>>>>> +	chain->ch_len = idx;
>>>>>> +	list_for_each_entry_continue(chain, &cp->ccwchain_list, next) {
>>>>>> +		chain->ch_len = 0;
>>>>>> +	}
>>>>>> +	return ret;
>>>>>>    }
>>>>>>
>>>>>>    /**
>>>>>>   
>>>
>>
>