apiutil.c

ertfs文件系统里面既有完整ucos程序

/*
* EBS - RTFS (Real Time File Manager)
*
* Copyright EBS Inc. 1996
* All rights reserved.
* This code may not be redistributed in source or linkable object form
* without the consent of its author.
*/

/* APIUTIL.C - Contains support code for user api level source code.

    The following routines are included:

    pc_fd2file      -   Map a file descriptor to a file structure.
    pc_allocfile    -   Allocate a file structure.
    pc_freefile     -   Release a file structure.
    pc_free_all_fil -   Release all file structures for a drive.
    pc_log_base_2   -   Calculate log2(N).
    pc_get_cwd      -   Determine cwd string from current directory inode.
    pc_upstat       -   Copy directory entry info to a user's stat buffer  
    _synch_file_ptrs -  make sure file pointers are synchronyzed
    get_disk_volume -   Get the voulme label from a boot block

*/


#ifndef __PCDISK__  /* This allows us to build the lib with subroutines split */
#include "pcdisk.h"
#endif

RTFS_FILE(chkdrive.c, check_drive)


#ifndef __PCDISK__  /* This allows us to build the lib with subroutines split */
#include <pcdisk.h>
#endif

/* Check if a drive id is valid and mount the drive. This is an internal
   routine that is called by other api calls */

int check_drive(char *name)  /*__fn__*/
{
int driveno;
    set_errno(0);

    /* Get the drive and make sure it is mounted   */
    if (pc_parsedrive( &driveno, name))
    {
        //OS_CLAIM_LOGDRIVE(driveno)  /* Register drive in use */
        //if (!check_media_entry(driveno) || !pc_drno2dr(driveno))
        //{
        //    OS_RELEASE_LOGDRIVE(driveno)
        //    set_errno(PEDEVICE);
        //    return(-1);
        //}
        //OS_RELEASE_LOGDRIVE(driveno)
    }
    else
    {
        set_errno(PEDEVICE);
        return(-1);
    }
    return(driveno);
}

/* written by Meter.chen */
int mount_drive(char *name)
{
int driveno;
    set_errno(0);

    /* Get the drive and make sure it is mounted   */
    if (pc_parsedrive( &driveno, name))
    {
        OS_CLAIM_LOGDRIVE(driveno)  /* Register drive in use */
        if (!check_media_entry(driveno) || !pc_drno2dr(driveno))
        {
            OS_RELEASE_LOGDRIVE(driveno)
            set_errno(PEDEVICE);
            return(-1);
        }
        OS_RELEASE_LOGDRIVE(driveno)
    }
    else
    {
        set_errno(PEDEVICE);
        return(-1);
    }
    return(driveno);
}

/* pc_i_dskopen() and get_disk_volume() are used to mount a disk.
   they are called by the check media code */

BOOLEAN pc_i_dskopen(int driveno)                                       /*__fn__*/
{
    BOOLEAN  ret_val;
    DDRIVE *pdr;

    ret_val = pc_dskinit((int)driveno);
    if (ret_val)
    {
        pdr = pc_drno2dr((int)driveno);
        if (pdr)
        {
            get_disk_volume((int)driveno, pdr->volume_label, &pdr->volume_serialno);
        }
    }
    return(ret_val);
}


BOOLEAN get_disk_volume(int driveno, byte *pvollabel, dword *pserialno) /*__fn__*/
{
    BLKBUFF *rbuf;
    BOOLEAN ret_val;
    rbuf = pc_scratch_blk();
    if (!rbuf)
        return(FALSE);
    *pvollabel = 0;
    
    if (devio_read(driveno, 0, rbuf->data , 1, FALSE))
    {
        ret_val = TRUE;
        *pserialno = to_DWORD(&rbuf->data[0x27]); /* Volume serial # */
#if (FAT32)
/*   if(pbl0->numroot==0) - see gblk0   */
     if (to_WORD(&rbuf->data[0x11])==0)
          copybuff( pvollabel,&rbuf->data[0x47],11); /* Volume label (4.0) */
     else
#endif
          copybuff( &pvollabel[0],&rbuf->data[0x2b],11); /* Volume label (4.0) */
        pvollabel[11] = 0;
    }
    else
        ret_val = FALSE;

    pc_free_buf(rbuf, TRUE);
    return(ret_val);
}




RTFS_FILE(fd2file.c, pc_fd2file)

#ifndef __PCDISK__  /* This allows us to build the lib with subroutines split */
#include <pcdisk.h>
#endif

/****************************************************************************
    Miscelaneous File and file descriptor management functions

    These functions are private functions used by the po_ file io routines.

    pc_fd2file -
        Map a file descriptor to a file structure. Return null if the file is
        not open. If an error has occured on the file return NULL unless 
        allow_err is true.
    
    pc_allocfile -
        Allocate a file structure an return its handle. Return -1 if no more 
        handles are available.

    pc_freefile -
        Free all core associated with a file descriptor and make the descriptor
        available for future calls to allocfile.

    pc_free_all_fil -
*****************************************************************************/

/*  Map a file descriptor to a file structure. Return null if the file is
    not open or the flags don't match (test for write access if needed). 
*/

PC_FILE *pc_fd2file(PCFD fd,int flags)                      /*__fn__*/
{
    PC_FILE *pfile;
    PC_FILE *pret_val;

    OS_CLAIM_FSCRITICAL()
    pret_val = 0; 
    if (0 <= fd && fd <= pc_nuserfiles())
    {
        pfile = mem_file_pool+fd;
        if (pfile && !pfile->is_free)
        {
            /* If flags == 0. Any access allowed. Otherwise at least one
            bit in the file open flags must match the flags sent in */
            if (!flags || (pfile->flag&flags))
            {
                pret_val = pfile;
            }
        }
    }
    OS_RELEASE_FSCRITICAL()
    return(pret_val);
}

RTFS_FILE(allocfil.c, pc_allocfile)

#ifndef __PCDISK__  /* This allows us to build the lib with subroutines split */
#include <pcdisk.h>
#endif

/* Assign zeroed out file structure to an FD and return the handle. Return 
    -1 on error. */
PCFD pc_allocfile(void)                                         /*__fn__*/
{
    PC_FILE *pfile;
    PCFD i;

    OS_CLAIM_FSCRITICAL()
    pfile = mem_file_pool;
    for (i=0;i<pc_nuserfiles();i++, pfile++)
    {
        if (pfile->is_free)
        {
            pc_memfill(pfile, sizeof(PC_FILE), (byte) 0);
            OS_RELEASE_FSCRITICAL()
            return(i);
        }
    }
    OS_RELEASE_FSCRITICAL()
    return (-1);
}

RTFS_FILE(freefile.c, pc_freefile)

#ifndef __PCDISK__  /* This allows us to build the lib with subroutines split */
#include <pcdisk.h>
#endif

/* Free core associated with a file descriptor. Release the FD for later use   */
void pc_freefile(PCFD fd)                                       /*__fn__*/
{
    PC_FILE *pfile;

    if ( (pfile = pc_fd2file(fd, 0)) == 0)
        return;
    if (pfile->pobj)
        pc_freeobj(pfile->pobj);
    pfile->is_free = TRUE;
}

RTFS_FILE(freallfi.c, pc_free_all_fil)

#ifndef __PCDISK__  /* This allows us to build the lib with subroutines split */
#include <pcdisk.h>
#endif


RTFS_FILE(freallfi.c, pc_free_all_fil)

#ifndef __PCDISK__  /* This allows us to build the lib with subroutines split */
#include <pcdisk.h>
#endif

#define ENUM_FLUSH 1
#define ENUM_TEST  2 
#define ENUM_FREE  3

/* Release all file descriptors associated with a drive and free up all core
    associated with the files
    called by dsk_close 
*/
int pc_enum_file(DDRIVE *pdrive, int chore)             /*__fn__*/
{
    PC_FILE *pfile;
    PCFD i;
    int dirty_count;

    dirty_count = 0;
    for (i=0; i < pc_nuserfiles(); i++)
    {
        pfile = pc_fd2file(i, 0);
        if (pfile)
        {
            if ((pfile->pobj) && (pfile->pobj->pdrive == pdrive))
            {
                /* print a debug message since in normal operation 
                all files should be close closed before closing the drive */
#if (RTFS_WRITE)
                if (chore == ENUM_FLUSH)
                {
                    if (!_po_flush(pfile))
                        return(-1);
                }
#endif
                if (chore == ENUM_TEST)
                {
                    if (pfile->needs_flush)
                        dirty_count += 1;
                }
                if (chore == ENUM_FREE)
                {
                    pc_freefile(i);
                }
            }
        }
    }
    return(dirty_count);
}


/* Release all file descriptors associated with a drive and free up all core
    associated with the files
    called by dsk_close 
*/
void pc_free_all_fil(DDRIVE *pdrive)                                /*__fn__*/
{
    pc_enum_file(pdrive, ENUM_FREE);
}
#if (RTFS_WRITE)
/* Flush all files on a drive   */
BOOLEAN pc_flush_all_fil(DDRIVE *pdrive)                                /*__fn__*/
{
    if (pc_enum_file(pdrive, ENUM_FLUSH) == 0)
        return(TRUE);
    else
        return(FALSE);
}
#endif
/* Test the dirty flag for all files   */
int pc_test_all_fil(DDRIVE *pdrive)                             /*__fn__*/
{
    return(pc_enum_file(pdrive, ENUM_TEST));
}



RTFS_FILE(cwd.c, pc_cwd)

#ifndef __PCDISK__  /* This allows us to build the lib with subroutines split */
#include <pcdisk.h>
#endif

/***************************************************************************
    PC_CWD -  Get the current working directory for a drive,

 Description
    Return the current directory inode for the drive represented by ddrive. 

***************************************************************************/