[LTP] [PATCH v1] aiocp: Filter out O_DIRECT before read

[Andrea Cervesato]

Hi,

On 2/9/23 12:06, Cyril Hrubis wrote:
> Hi!
>> When aiocp executed with -f DIRECT will fail.
>>
>> <<<test_start>>>
>> tag=AD049 stime=1675520824
>> cmdline="aiocp -b 8k -n 8 -f DIRECT"
>> contacts=""
>> analysis=exit
>> <<<test_output>>>
>> tst_test.c:1560: TINFO: Timeout per run is 0h 30m 30s
>> aiocp.c:211: TINFO: Maximum AIO blocks: 65536
>> tst_device.c:585: TINFO: Use uevent strategy
>> aiocp.c:250: TINFO: Fill srcfile.bin with random data
>> aiocp.c:279: TINFO: Copy srcfile.bin -> dstfile.bin
>> aiocp.c:291: TINFO: Comparing srcfile.bin with dstfile.bin
>> aiocp.c:306: TBROK: read(3,0x7ffcd743abe0,4096) failed, returned -1: EINVAL (22)
>> ...
>>
>> syscall read manual ERROR section said that:
>> EINVAL fd  is  attached to an object which is unsuitable for reading;
>> or the file was opened with the O_DIRECT flag, and either the address
>> specified in buf, the value specified in  count, or the file offset is
>> not suitably aligned.
>>
>> We need filter out O_DIRECT flag before read.
> This is not very good changelog, I had to look closely at the source to
> figure out why we may need this.
>
> Better description should say that the code which checks that the data
> has been written correctly does not use aligned buffers, which may cause
> a failure like the one above.
>
>> Signed-off-by: Ping Fang <pifang@redhat.com>
>> ---
>>   testcases/kernel/io/ltp-aiodio/aiocp.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/testcases/kernel/io/ltp-aiodio/aiocp.c b/testcases/kernel/io/ltp-aiodio/aiocp.c
>> index bc0e209b2..e4252d641 100644
>> --- a/testcases/kernel/io/ltp-aiodio/aiocp.c
>> +++ b/testcases/kernel/io/ltp-aiodio/aiocp.c
>> @@ -297,8 +297,8 @@ static void run(void)
>>   		return;
>>   	}
>>   
>> -	srcfd = SAFE_OPEN(srcname, srcflags | O_RDONLY, 0666);
>> -	dstfd = SAFE_OPEN(dstname, srcflags | O_RDONLY, 0666);
>> +	srcfd = SAFE_OPEN(srcname, (srcflags & ~O_DIRECT) | O_RDONLY, 0666);
>> +	dstfd = SAFE_OPEN(dstname, (srcflags & ~O_DIRECT) | O_RDONLY, 0666);
> I guess that we can as well just remove the srcflags and keep just the
> O_RDONLY since the srcflags are by definition either O_RDONLY or
> O_DIRECT | O_RDONLY.
>
> I suppose that using scrflags and dstflags for anything else than the
> filedescriptors passed to the async_run() is actually a mistake.
>
I agree with this. Probably we only need:

     srcfd = SAFE_OPEN(srcname, O_RDONLY, 0666);
     dstfd = SAFE_OPEN(dstname, O_RDONLY, 0666);

>>   	reads = howmany(filesize, buffsize);
>>   
>> -- 
>> 2.31.1
>>
>>
>> -- 
>> Mailing list info: https://lists.linux.it/listinfo/ltp

Regards,
Andrea Cervesato