rom/dos/addbuffers.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Add or remove cache memory from a filesystem.
   6     Lang: English
   7 */
   8 #include <proto/exec.h>
   9 #include <dos/dosextens.h>
  10 #include <dos/filesystem.h>
  11 #include "dos_intern.h"
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16 #include <proto/dos.h>
  17
  18         AROS_LH2(LONG, AddBuffers,
  19
  20 /*  SYNOPSIS */
  21         AROS_LHA(CONST_STRPTR, devicename, D1),
  22         AROS_LHA(LONG,         numbuffers, D2),
  23
  24 /*  LOCATION */
  25         struct DosLibrary *, DOSBase, 122, Dos)
  26
  27 /*  FUNCTION
  28         Add or remove cache memory from a filesystem.
  29
  30     INPUTS
  31         devicename  --  NUL terminated dos device name.
  32         numbuffers  --  Number of buffers to add. May be negative.
  33
  34     RESULT
  35         != 0 on success (IoErr() gives the actual number of buffers),
  36         0 else (IoErr() gives the error code).
  37
  38     NOTES
  39
  40     EXAMPLE
  41
  42     BUGS
  43
  44     SEE ALSO
  45
  46     INTERNALS
  47
  48     The error value in case of a filesystem error will be reported in
  49     the io_MORE_CACHE.io_NumBuffers field.
  50
  51 *****************************************************************************/
  52
  53 {
  54     AROS_LIBFUNC_INIT
  55
  56     struct DevProc *dvp;
  57     LONG err;
  58
  59     /* Use stackspace for IO request. */
  60     struct IOFileSys iofs;
  61
  62     /* setup */
  63     InitIOFS(&iofs, FSA_MORE_CACHE, DOSBase);
  64     iofs.io_Union.io_MORE_CACHE.io_NumBuffers = numbuffers;
  65
  66     /* get the device */
  67     if ((dvp = GetDeviceProc(devicename, NULL)) == NULL)
  68         return DOSFALSE;
  69
  70     /* we're only interested in real devices */
  71     if (dvp->dvp_DevNode->dol_Type != DLT_DEVICE) {
  72         FreeDeviceProc(dvp);
  73         SetIoErr(ERROR_DEVICE_NOT_MOUNTED);
  74         return DOSFALSE;
  75     }
  76
  77     err = DoIOFS(&iofs, dvp, NULL, DOSBase);
  78
  79     FreeDeviceProc(dvp);
  80
  81     if (err != 0)
  82         return DOSFALSE;
  83
  84     /* caller expects the new number of buffers in IoErr() */
  85     SetIoErr(iofs.io_Union.io_MORE_CACHE.io_NumBuffers);
  86     return DOSTRUE;
  87
  88     AROS_LIBFUNC_EXIT
  89 } /* AddBuffers */