rom/partition/fsloader.c

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