Re: [PATCH v2] block: wrong return value

[Jens Axboe <axboe@kernel.dk>]

On 10/23/2014 10:28 AM, Sudip Mukherjee wrote:
> On Thu, Oct 23, 2014 at 10:09:36AM -0600, Jens Axboe wrote:
>> On 10/23/2014 10:04 AM, Sudip Mukherjee wrote:
>>> while compiling integer err was showing as a set but unused variable.
>>> elevator_init_fn can be either cfq_init_queue or deadline_init_queue
>>> or noop_init_queue.
>>> all three of these functions are returning -ENOMEM if they fail to
>>> allocate the queue.
>>> so we should actually be returning the error code rather than
>>> returning 0 always.
>>>
>>> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
>>> ---
>>>
>>> change in v2: added elevator_put
>>>
>>>  block/elevator.c | 6 ++++--
>>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/block/elevator.c b/block/elevator.c
>>> index 24c28b6..1267c2b 100644
>>> --- a/block/elevator.c
>>> +++ b/block/elevator.c
>>> @@ -184,7 +184,7 @@ static void elevator_release(struct kobject *kobj)
>>>  int elevator_init(struct request_queue *q, char *name)
>>>  {
>>>  	struct elevator_type *e = NULL;
>>> -	int err;
>>> +	int err = 0;
>>
>> Why init it to 0?
> not required actually. my initial thinking was that we are returning 0 on success or else the error code. so gave it a default value of 0.
> but elevator_init_fn is returning 0 on success , so we will get 0 even if we do not initialize it.
> should i resend after modifying it?

Yes resend it please, the assignment is meaningless as it is overwritten
later before being used.

-- 
Jens Axboe