Re: linux /dev and normal files

[Jens Axboe <axboe@kernel.dk>]

On 05/12/2015 12:34 PM, Elliott, Robert (Server Storage) wrote:
>
>> -----Original Message-----
>> From: Jens Axboe [mailto:axboe@kernel.dk]
>> Sent: Tuesday, May 12, 2015 10:33 AM
>> To: Elliott, Robert (Server Storage); fio@vger.kernel.org
>> Cc: Sitsofe Wheeler; Jon Tango
>> Subject: Re: linux /dev and normal files
>>
>> On 04/03/2015 02:24 PM, Jens Axboe wrote:
>>> On 04/03/2015 12:13 PM, Elliott, Robert (Server Storage) wrote:
>>>>
>>>>
>>>>> -----Original Message-----
>>>>> From: fio-owner@vger.kernel.org [mailto:fio-owner@vger.kernel.org] On
>>>>> Behalf Of Jens Axboe
>>>>> Sent: Thursday, October 2, 2014 1:32 PM
>>>>> To: Elliott, Robert (Server Storage); fio@vger.kernel.org
>>>>> Cc: Sitsofe Wheeler; Jon Tango
>>>>> Subject: Re: linux /dev and normal files
>>>>>
>>>>> On 10/02/2014 12:21 PM, Elliott, Robert (Server Storage) wrote:
>>>>>>>>> It might be better to continue to attempt to run the
>>>>>>>>> other jobs.
>>>>>>>>
>>>>>>>> We should just go for the simpler create/nocreate solution, I
>> prefer
>>>>>>>> that. This is too involved, and it's hard to get all the cases
>> right
>>>>>>>> since there are a bunch of different ways that files are added.
>> Which
>>>>>>>> was why this patch only focused on filename=, since that is the one
>>>>> that
>>>>>>>> is the most interesting. But it still isn't pretty. If we add the
>>>>>>>> allow_file_create option, it's basically a two-liner change in a
>> few
>>>>>>>> places to not use O_CREAT.
>>>>>>>
>>>>>>> That took roughly 4 minutes... Does this work? Set
>> allow_file_create=0
>>>>>>> to disallow creating new files.
>>>> ...
>>>>>
>>>>> OK, let me test that, will spin a new one.
>>>>
>>>> I don't think this ever got added.
>>>
>>> It didn't... Did you re-test? No reason we can't get it added, I'll look
>>> into it start next week.
>>
>> Robert, I added this. Can you check current -git and see if it behaves
>> as expected for you?
>>
>
> Looks good.  Adding
> allow_file_create=0
>
> prevents it from creating files in /dev when the specified path
> does not exist and size= is specified.
>
> Starting 80 threads
> drive_0: Laying out IO file(s) (1 file(s) / 10MB)
> fio: file creation disallowed by allow_file_create=0
> drive_0: Laying out IO file(s) (1 file(s) / 10MB)
> fio: file creation disallowed by allow_file_create=0
> drive_0: Laying out IO file(s) (1 file(s) / 10MB)
> fio: file creation disallowed by allow_file_create=0

Perfect, thanks for (re) testing.

-- 
Jens Axboe