[mpich-discuss] ROMIO: Patch to run on Lustre

[Rob Latham]

On Fri, Sep 17, 2010 at 01:17:22PM +0200, Pascal Deveze wrote:

> After initializing lum->lmm_stripe_count to a "correct value", this
> problem disappears.
> I think this is a Lustre bug, but I propose to integer this patch:

thanks, pascal!

> --- src/mpi/romio/adio/ad_lustre/ad_lustre_open.c       2010-09-17
> 12:50:58.000000000 +0200
> +++ src/mpi/romio/adio/ad_lustre/ad_lustre_open.c.OLD   2010-05-25
> 20:59:13.000000000 +0200
> @@ -59,9 +59,6 @@
>                  MAX_LOV_UUID_COUNT * sizeof(struct lov_user_ost_data);
>         lum = (struct lov_user_md *)ADIOI_Malloc(lumlen);
>         lum->lmm_magic = LOV_USER_MAGIC;
> -       /* Initialize lum->lmm_stripe_count with a value else
> ioctl() returns an error */
> -       /* This value must be greater or egal than the existing
> lmm_stripe_count (bug in Lustre ?) */
> -        lum->lmm_stripe_count = -1;
>         err = ioctl(fd->fd_sys, LL_IOC_LOV_GETSTRIPE, (void *)lum);
>         if (!err) {
>             value = (char *)
> ADIOI_Malloc((MPI_MAX_INFO_VAL+1)*sizeof(char));

What if instead of explicitly initializing elements of the struct
lov_user_md, we called ADIOI_Calloc(1, lumlen) to set
everything in the struct to zero?  then if that struct changes in
lustre-2.0 or lustre-5.0 or whatever we'll still be covered..  Or,
would zero also give that error about value too large?

==rob

-- 
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA