/* lftruncate.c - lftruncate */

#include 

/*------------------------------------------------------------------------
 * lftruncate  -  Truncate a file by freeing its index and data blocks
 *                      (assumes directory mutex held)
 *------------------------------------------------------------------------
 */
status  lftruncate (
          struct lflcblk *lfptr         /* Ptr to file's cntl blk entry */
        )
{
        struct  ldentry *ldptr;         /* Pointer to file's dir. entry */
        struct  lfiblk  iblock;         /* Buffer for one index block   */
        ibid32  ifree;                  /* Start of index blk free list */
        ibid32  firstib;                /* First index blk of the file  */
        ibid32  nextib;                 /* Walks down list of the       */
                                        /*   file's index blocks        */
        dbid32  nextdb;                 /* Next data block to free      */
        int32   i;                      /* Moves through data blocks in */
                                        /*   a given index block        */

        ldptr = lfptr->lfdirptr;        /* Get pointer to dir. entry    */
        if (ldptr->ld_size == 0) {      /* File is already empty */
                return OK;
        }

        /* Clean up the open local file first */

        if ( (lfptr->lfibdirty) || (lfptr->lfdbdirty) ) {
                lfflush(lfptr);
        }
        lfptr->lfpos = 0;
        lfptr->lfinum = LF_INULL;
        lfptr->lfdnum = LF_DNULL;
        lfptr->lfbyte = &lfptr->lfdblock[LF_BLKSIZ];

        /* Obtain ID of first index block on free list */

        ifree = Lf_data.lf_dir.lfd_ifree;

        /* Record file's first i-block and clear directory entry */

        firstib = ldptr->ld_ilist;
        ldptr->ld_ilist = LF_INULL;
        ldptr->ld_size = 0;
        Lf_data.lf_dirdirty = TRUE;

        /* Walk along index block list, disposing of each data block    */
        /*   and clearing the corresponding pointer.  A note on loop    */
        /*   termination: last pointer is set to ifree below.           */

        for (nextib=firstib; nextib!=ifree; nextib=iblock.ib_next) {

                /* Obtain a copy of current index block from disk       */

                lfibget(Lf_data.lf_dskdev, nextib, &iblock);

                /* Free each data block in the index block              */

                for (i=0; i