Re: AIO, DIO fsx tests failures on 2.6.19-rc1-mm1

[Badari Pulavarty <pbadari@us.ibm.com>]

Andrew Morton wrote:
> On Tue, 17 Oct 2006 15:31:49 -0700
> Badari Pulavarty <pbadari@us.ibm.com> wrote:
>
>   
>> Andrew Morton wrote:
>>     
>>> On Mon, 16 Oct 2006 13:38:19 -0700
>>> Badari Pulavarty <pbadari@us.ibm.com> wrote:
>>>
>>>   
>>>       
>>>>> So the answer is that -rc1-mm1 doesn't quite have the most recent
>>>>> version of this patch.  Grab the final patch at the end of this post
>>>>> from Andrew:
>>>>>
>>>>> 	http://lkml.org/lkml/2006/10/11/234
>>>>>
>>>>> It fixes up a misunderstanding that came from
>>>>> generic_file_buffered_write()'s habit of adding its 'written' input into
>>>>> the amount of bytes it announces having written in its return value.
>>>>>
>>>>> From mm-commits it looks like -mm2 will have the full patch.
>>>>>
>>>>>       
>>>>>           
>>>> Hmm.. with that patch applied, I still have fsx failures.
>>>> This time read() returning -EINVAL. Are there any other fixes
>>>> missing in -mm ?
>>>>     
>>>>         
>>> Probably.  I need to get off butt and prepare rc2-mm1.
>>>
>>> The below is the full patch against 2.6.19-rc2.  Please test this version.
>>>
>>>
>>> From: Jeff Moyer <jmoyer@redhat.com>
>>>
>>> When direct-io falls back to buffered write, it will just leave the dirty data
>>> floating about in pagecache, pending regular writeback.
>>>
>>> But normal direct-io semantics are that IO is synchronous, and that it leaves
>>> no pagecache behind.
>>>
>>> So change the fallback-to-buffered-write code to sync the file region and to
>>> then strip away the pagecache, just as a regular direct-io write would do.
>>>
>>>   
>>>       
>> Okay. Finally tracked down the problem I am running into.
>> This happens only on reiserfs
>>
>> # /root/fsx-linux -N 10000 -o 128000 -r 2048 -w 4096 -Z -R -W
>> jnk
>> mapped writes DISABLED
>> truncating to largest ever: 0x32740
>> truncating to largest ever: 0x39212
>> truncating to largest ever: 0x3bae9
>> truncating to largest ever: 0x3c1e3
>> truncating to largest ever: 0x3d1cd
>> truncating to largest ever: 0x3e8b8
>> truncating to largest ever: 0x3ed14
>> truncating to largest ever: 0x3f9c2
>> truncating to largest ever: 0x3ff9f
>> doread: read: Invalid argument
>> Segmentation fault
>>
>> Here is the strace for it
>> ..
>> ftruncate(3, 2721)                      = 0
>> fstat(3, {st_mode=S_IFREG|0644, st_size=2721, ...}) = 0
>> lseek(3, 0, SEEK_END)                   = 2721
>> fstat(3, {st_mode=S_IFREG|0644, st_size=2721, ...}) = 0
>> lseek(3, 0, SEEK_END)                   = 2721
>> fstat(3, {st_mode=S_IFREG|0644, st_size=2721, ...}) = 0
>> lseek(3, 0, SEEK_END)                   = 2721
>> lseek(3, 0, SEEK_SET)                   = 0
>> read(3, 0x50a800, 2048)                 = -1 EINVAL (Invalid argument)
>>
>> reiserfs getblock() is returing -EINVAL. There is comment in the code
>> about tail handling and returning EINVAL. BTW, this is not a -mm
>> issue, it happens on mainline too...
>>
>>     
>
> Does it fail in mainline, or only in
> mainline+direct-io-sync-and-invalidate-file-region-when-falling-back-to-buffered-write.patch?
>
>   
It fails on mailine (2.6.19-rc1). I will double check my tree just in case..

Thanks,
Badari