/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2017 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
 *                         University of Stuttgart.  All rights reserved.
 * Copyright (c) 2004-2005 The Regents of the University of California.
 *                         All rights reserved.
 * Copyright (c) 2008-2018 University of Houston. All rights reserved.
 * Copyright (c) 2015-2018 Research Organization for Information Science
 *                         and Technology (RIST). All rights reserved.
 * Copyright (c) 2016-2017 IBM Corporation. All rights reserved.
 * $COPYRIGHT$
 *
 * Additional copyrights may follow
 *
 * $HEADER$
 */


#include "ompi_config.h"
#include "fs_lustre.h"

#include <fcntl.h>
#include <unistd.h>
#include "mpi.h"
#include "ompi/constants.h"
#include "ompi/mca/fs/fs.h"
#include "ompi/communicator/communicator.h"
#include "ompi/info/info.h"

#include <sys/ioctl.h>

static void *alloc_lum(void);

static void *alloc_lum(void)
{
  int v1, v3;

  v1 = sizeof(struct lov_user_md_v1) +
    LOV_MAX_STRIPE_COUNT * sizeof(struct lov_user_ost_data_v1);
  v3 = sizeof(struct lov_user_md_v3) +
    LOV_MAX_STRIPE_COUNT * sizeof(struct lov_user_ost_data_v1);

  return malloc(MAX(v1, v3));
}

/*
 *	file_open_lustre
 *
 *	Function:	- opens a new file
 *	Accepts:	- same arguments as MPI_File_open()
 *	Returns:	- Success if new file handle
 */

int
mca_fs_lustre_file_open (struct ompi_communicator_t *comm,
                     const char* filename,
                     int access_mode,
                     struct opal_info_t *info,
                     ompio_file_t *fh)
{
    int amode, rank;
    int old_mask, perm;
    int rc, ret=OMPI_SUCCESS;
    int flag;
    int fs_lustre_stripe_size = -1;
    int fs_lustre_stripe_width = -1;
    char char_stripe[MPI_MAX_INFO_KEY];

    struct lov_user_md *lump=NULL;

    if (fh->f_perm == OMPIO_PERM_NULL) {
        old_mask = umask(022);
        umask(old_mask);
        perm = old_mask ^ 0666;
    }
    else {
        perm = fh->f_perm;
    }
    
    rank = fh->f_rank;

    amode = 0;
    if (access_mode & MPI_MODE_RDONLY)
        amode = amode | O_RDONLY;
    if (access_mode & MPI_MODE_WRONLY)
        amode = amode | O_WRONLY;
    if (access_mode & MPI_MODE_RDWR)
        amode = amode | O_RDWR;

    opal_info_get (info, "stripe_size", MPI_MAX_INFO_VAL, char_stripe, &flag);
    if ( flag ) {
        sscanf ( char_stripe, "%d", &fs_lustre_stripe_size );
    }

    opal_info_get (info, "stripe_width", MPI_MAX_INFO_VAL, char_stripe, &flag);
    if ( flag ) {
        sscanf ( char_stripe, "%d", &fs_lustre_stripe_width );
    }

    if (fs_lustre_stripe_size < 0) {
        fs_lustre_stripe_size = mca_fs_lustre_stripe_size;
    }   

    if (fs_lustre_stripe_width < 0) {
        fs_lustre_stripe_width = mca_fs_lustre_stripe_width;
    }

    
    /* Reset errno */
    errno = 0;
    if (0 == fh->f_rank) {
       /* MODE_CREATE and MODE_EXCL can only be set by one process */
        if ( access_mode & MPI_MODE_CREATE )
            amode = amode | O_CREAT;
        if (access_mode & MPI_MODE_EXCL)
            amode = amode | O_EXCL;

        if ( (fs_lustre_stripe_size>0 || fs_lustre_stripe_width>0) &&
             ( amode&O_CREAT)                                      && 
             ( (amode&O_RDWR)|| amode&O_WRONLY) ) {
            llapi_file_create(filename,
                              fs_lustre_stripe_size,
                              -1, /* MSC need to change that */
                              fs_lustre_stripe_width,
                              0); /* MSC need to change that */
            
            fh->fd = open(filename, amode | O_LOV_DELAY_CREATE, perm);
        }
        else {
            fh->fd = open (filename, amode, perm);
        }
        if ( 0 > fh->fd ) {
            if ( EACCES == errno ) {
                ret = MPI_ERR_ACCESS;
            }
            else if ( ENAMETOOLONG == errno ) {
                ret = MPI_ERR_BAD_FILE;
            }
            else if ( ENOENT == errno ) {
                ret = MPI_ERR_NO_SUCH_FILE;
            }
            else if ( EISDIR == errno ) {
                ret = MPI_ERR_BAD_FILE;
            }
            else if ( EROFS == errno ) {
                ret = MPI_ERR_READ_ONLY;
            }
            else if ( EEXIST == errno ) {
                ret = MPI_ERR_FILE_EXISTS;
            }
            else {
                ret = MPI_ERR_OTHER;
            }
        }
    }

   comm->c_coll->coll_bcast ( &ret, 1, MPI_INT, 0, comm, comm->c_coll->coll_bcast_module);
    if ( OMPI_SUCCESS != ret ) {
        fh->fd = -1;
        return ret;
    }

    if ( 0 != rank ) {
        fh->fd = open (filename, amode, perm);
        if ( 0 > fh->fd) {
            if ( EACCES == errno ) {
                ret = MPI_ERR_ACCESS;
            }
            else if ( ENAMETOOLONG == errno ) {
                ret = MPI_ERR_BAD_FILE;
            }
            else if ( ENOENT == errno ) {
                ret = MPI_ERR_NO_SUCH_FILE;
            }
            else if ( EISDIR == errno ) {
                ret = MPI_ERR_BAD_FILE;
            }
            else if ( EROFS == errno ) {
                ret = MPI_ERR_READ_ONLY;
            }
            else if ( EEXIST == errno ) {
                ret = MPI_ERR_FILE_EXISTS;
            }
            else {
                ret = MPI_ERR_OTHER;
            }
        }
    }



    lump = alloc_lum();
    if (NULL == lump ){
	fprintf(stderr,"Cannot allocate memory for extracting stripe size\n");
	return OMPI_ERROR;
    }
    rc = llapi_file_get_stripe(filename, lump);
    if (rc != 0) {
        opal_output(1, "get_stripe failed: %d (%s)\n", errno, strerror(errno));
        return OMPI_ERROR;
    }
    fh->f_stripe_size   = lump->lmm_stripe_size;
    fh->f_stripe_count  = lump->lmm_stripe_count;
    fh->f_fs_block_size = lump->lmm_stripe_size;
    
    return OMPI_SUCCESS;
}