lflclose.c

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/* lflclose.c - lflclose.c */

#include <xinu.h>

/*------------------------------------------------------------------------
 * lflclose  -  Close a file by flushing output and freeing device entry
 *------------------------------------------------------------------------
 */
devcall lflclose (
      struct dentry *devptr     /* Entry in device switch table */
    )
{
    struct  lflcblk *lfptr;     /* Ptr to open file table entry */

    /* Obtain exclusive use of the file */

    lfptr = &lfltab[devptr->dvminor];
    wait(lfptr->lfmutex);

    /* If file is not open, return an error */

    if (lfptr->lfstate != LF_USED) {
        signal(lfptr->lfmutex);
        return SYSERR;
    }

    /* Write index or data blocks to disk if they have changed */

    if (Lf_data.lf_dirdirty || lfptr->lfdbdirty || lfptr->lfibdirty) {
        lfflush(lfptr);
    }

    /* Set device state to FREE and return to caller */

    lfptr->lfstate = LF_FREE;
    signal(lfptr->lfmutex);
    return OK;
}