rom/dos/addbuffers.c

   1 /*
   2     Copyright © 1995-2014, 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_intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/dos.h>
  16
  17         AROS_LH2(LONG, AddBuffers,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(CONST_STRPTR, devicename, D1),
  21         AROS_LHA(LONG,         numbuffers, D2),
  22
  23 /*  LOCATION */
  24         struct DosLibrary *, DOSBase, 122, Dos)
  25
  26 /*  FUNCTION
  27         Add or remove cache memory to/from a filesystem. The amount of memory
  28         per cache buffer and the limit depends on the filesystem.
  29
  30     INPUTS
  31         devicename - DOS device name (with trailing ':' and NUL terminated).
  32         numbuffers - Number of buffers to add. May be negative for decreasing.
  33
  34     RESULT
  35         DOSTRUE on success (IoErr() gives the actual number of buffers).
  36         DOSFALSE on error (IoErr() gives the error code).
  37
  38     NOTES
  39         Although some old filesystems return the new buffer count instead of
  40         a success indication, a work-around for that case is built into the
  41         AROS implementation of this function.
  42
  43     EXAMPLE
  44         LONG res1, res2;
  45         res1 = AddBuffers("DF0:", 10);
  46         res2 = IoErr();
  47
  48     BUGS
  49
  50     SEE ALSO
  51         IoErr()
  52
  53     INTERNALS
  54
  55 *****************************************************************************/
  56
  57 {
  58     AROS_LIBFUNC_INIT
  59
  60     struct DevProc *dvp;
  61     LONG ret, error;
  62
  63     /* get the device */
  64     if ((dvp = GetDeviceProc(devicename, NULL)) == NULL)
  65         return DOSFALSE;
  66
  67     /* we're only interested in real devices */
  68     if (dvp->dvp_DevNode == NULL ||
  69         dvp->dvp_DevNode->dol_Type != DLT_DEVICE) {
  70         FreeDeviceProc(dvp);
  71         SetIoErr(ERROR_DEVICE_NOT_MOUNTED);
  72         return DOSFALSE;
  73     }
  74
  75     ret = dopacket1(DOSBase, NULL, dvp->dvp_Port, ACTION_MORE_CACHE, numbuffers);
  76
  77     if (ret > 0)
  78     {
  79         error = ret;
  80         ret = DOSTRUE;
  81     }
  82     else
  83         error = IoErr();
  84
  85     FreeDeviceProc(dvp);
  86
  87     SetIoErr(error);
  88
  89     return ret;
  90
  91     AROS_LIBFUNC_EXIT
  92 } /* AddBuffers */