[mvapich-discuss] open non-existing files on Lustre expecting MPI_ERR_NO_SUCH_FILE but got MPI_SUCCESS

[Hari Subramoni]

Hello Wei-keng,

Can you please try the attached patch and see if things work for you?

This patch will be available by default with future releases of the
MVAPICH2 library.

Best Regards,
Hari.

On Tue, Feb 7, 2017 at 4:50 AM, Hari Subramoni <subramoni.1 at osu.edu> wrote:

> Hello Wei-keng,
>
> Many thanks for the report. We will take a look at it and get back to you
> soon.
>
> Best Regards,
> Hari.
>
> On Feb 7, 2017 1:12 AM, "Wei-keng Liao" <wkliao at eecs.northwestern.edu>
> wrote:
>
>> Hi,
>>
>> I am a developer of PnetCDF library and would like to file a bug report.
>> Mark Dixon, a PnetCDF user cc-ed in this email, reported an error when
>> building PnetCDF with mvapich2-2.2. The root cause of the error is due to
>> mvapich2-2.2 fails to return the expected MPI error class
>> MPI_ERR_NO_SUCH_FILE
>> when a test program tries to open a non-existing file on Lustre.
>>
>> After some diggings, I found out that the Lustre driver in mvapich2
>> appends
>> O_CREAT flag to the mode argument of the open call, (line 50, in file
>> src/mpi/romio/adio/ad_lustre/ad_lustre_open.c). Because of that, the
>> file is
>> mistakenly created and MPI_SUCCESS is returned, which is an unexpected
>> outcome
>> by MPI standard.
>>
>> Attached is a small MPI program to reproduce such error. Mark has used it
>> to
>> verify the issue described above. He also ran it against an ext4 (UFS)
>> and the
>> correct error class was returned. So the problem is specific for Lustre
>> driver.
>> Please see the discussion email threads:
>> http://lists.mcs.anl.gov/pipermail/parallel-netcdf/2017-
>> February/001897.html
>>
>>
>> Wei-keng
>>
>>
>> _______________________________________________
>> mvapich-discuss mailing list
>> mvapich-discuss at cse.ohio-state.edu
>> http://mailman.cse.ohio-state.edu/mailman/listinfo/mvapich-discuss
>>
>>
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