rom/partition/fsloader.c

   1 /*
   2     Copyright © 1995-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 /*
   7  * This hook is called after dos.library wakes up.
   8  * Its job is to load all queued filesystems and add to the system.
   9  */
  10
  11 #include <aros/asmcall.h>
  12 #include <aros/debug.h>
  13 #include <exec/resident.h>
  14 #include <resources/filesysres.h>
  15 #include <proto/alib.h>
  16 #include <proto/dos.h>
  17 #include <proto/exec.h>
  18 #include <proto/partition.h>
  19
  20 #include "partition_support.h"
  21 #include "fsloader.h"
  22
  23 static struct FileSysEntry *FindResidentFS(struct FileSysResource *fsr, ULONG dostype, ULONG version)
  24 {
  25     struct FileSysEntry *fsrnode;
  26
  27     ForeachNode(&fsr->fsr_FileSysEntries, fsrnode)
  28     {
  29         if (fsrnode->fse_DosType == dostype && fsrnode->fse_Version >= version)
  30             return fsrnode;
  31     }
  32
  33     return NULL;
  34 }
  35
  36 ULONG AddFS(struct Library *PartitionBase, struct FileSysHandle *fs)
  37 {
  38     struct DosLibrary *DOSBase = (struct DosLibrary *)((struct PartitionBase_intern *)PartitionBase)->pb_DOSBase;
  39     struct FileSysResource *fsr;
  40     struct FileSysEntry *fsrnode;
  41     ULONG dostype;
  42     ULONG version;
  43
  44     fsr = OpenResource("FileSystem.resource");
  45     if (!fsr)
  46         return ERROR_INVALID_RESIDENT_LIBRARY;
  47
  48     GetFileSystemAttrs(&fs->ln, FST_ID, &dostype, FST_VERSION, &version, TAG_DONE);
  49
  50     /*
  51      * First we want to check if we already have this filesystem in the resource.
  52      * Unfortunately the resource doesn't have any locking, so we have to use
  53      * Forbid()/Permit() pair. In order not to hold it for a while, we repeat
  54      * the check below after loading the handler (to eliminate race condition
  55      * when someone loads newer version of the filesystem that we are loading
  56      * at the moment.
  57      */
  58     Forbid();
  59     fsrnode = FindResidentFS(fsr, dostype, version);
  60     Permit();
  61
  62     if (fsrnode)
  63         return ERROR_OBJECT_EXISTS;
  64
  65     fsrnode = AllocVec(sizeof(struct FileSysEntry), MEMF_PUBLIC | MEMF_CLEAR);
  66     if (!fsrnode)
  67         return ERROR_NO_FREE_STORE;
  68
  69     GetFileSystemAttrs(&fs->ln, FST_FSENTRY, fsrnode, TAG_DONE);
  70     fsrnode->fse_SegList = LoadFileSystem(&fs->ln);
  71
  72     /*
  73      * FIXME: Name of the filesystem is currently not filled in.
  74      * I left it this way just because this was originally done in m68k-specific hack.
  75      * May be it should be added?
  76      */
  77
  78     if (fsrnode->fse_SegList)
  79     {
  80         struct FileSysEntry *dup;
  81
  82         /*
  83          * Repeat checking, and insert the filesystem only if still not found.
  84          * If found, unload our seglist and return error.
  85          * This really sucks but nothing can be done with it. Even if we implement
  86          * a global semaphore on the resource original m68k software won't know
  87          * about it.
  88          */
  89         Forbid();
  90
  91         dup = FindResidentFS(fsr, dostype, version);
  92         if (!dup)
  93             /*
  94              * Entries in the list are not sorted by priority.
  95              * Adding to head makes them sorted by version.
  96              */
  97             AddHead(&fsr->fsr_FileSysEntries, &fsrnode->fse_Node);
  98
  99         Permit();
 100
 101         if (dup)
 102         {
 103             UnLoadSeg(fsrnode->fse_SegList);
 104             FreeVec(fsrnode);
 105
 106             return ERROR_OBJECT_EXISTS;
 107         }
 108
 109         return 0;
 110     }
 111
 112     /* InternalLoadSeg() will leave its error code in IoErr() */
 113     return IoErr();
 114 }