Modules/FAT - Slight improvement to detection code

[tpg/acess2.git] / KernelLand / Modules / Filesystems / FAT / fatio.c

diff --git a/KernelLand/Modules/Filesystems/FAT/fatio.c b/KernelLand/Modules/Filesystems/FAT/fatio.c
index ab49b30..7bf62ef 100644 (file)
--- a/KernelLand/Modules/Filesystems/FAT/fatio.c
+++ b/KernelLand/Modules/Filesystems/FAT/fatio.c
@@ -5,7 +5,7 @@
  * fatio.c
  * - FAT Manipulation and Cluster IO
  */
-#define DEBUG  1
+#define DEBUG  0
 #include <acess.h>
 #include <vfs.h>
 #include "common.h"
@@ -20,14 +20,15 @@ Uint32 FAT_int_GetFatValue(tFAT_VolInfo *Disk, Uint32 cluster)
        Uint32  val = 0;
        Uint32  ofs;
        ENTER("pDisk xCluster", Disk, cluster);
+       
        Mutex_Acquire( &Disk->lFAT );
        #if CACHE_FAT
        if( Disk->ClusterCount <= giFAT_MaxCachedClusters )
        {
                val = Disk->FATCache[cluster];
-               if(Disk->type == FAT12 && val == EOC_FAT12)     val = -1;
-               if(Disk->type == FAT16 && val == EOC_FAT16)     val = -1;
-               if(Disk->type == FAT32 && val == EOC_FAT32)     val = -1;
+               if(Disk->type == FAT12 && val == EOC_FAT12)     val = GETFATVALUE_EOC;
+               if(Disk->type == FAT16 && val == EOC_FAT16)     val = GETFATVALUE_EOC;
+               if(Disk->type == FAT32 && val == EOC_FAT32)     val = GETFATVALUE_EOC;
        }
        else
        {
@@ -35,14 +36,15 @@ Uint32 FAT_int_GetFatValue(tFAT_VolInfo *Disk, Uint32 cluster)
                ofs = Disk->bootsect.resvSectCount*512;
                if(Disk->type == FAT12) {
                        VFS_ReadAt(Disk->fileHandle, ofs+(cluster/2)*3, 3, &val);
-                       val = (cluster & 1 ? val>>12 : val & 0xFFF);
-                       if(val == EOC_FAT12)    val = -1;
+                       LOG("3 bytes at 0x%x are (Uint32)0x%x", ofs+(cluster/2)*3, val);
+                       val = (cluster & 1) ? (val>>12) : (val & 0xFFF);
+                       if(val == EOC_FAT12)    val = GETFATVALUE_EOC;
                } else if(Disk->type == FAT16) {
                        VFS_ReadAt(Disk->fileHandle, ofs+cluster*2, 2, &val);
-                       if(val == EOC_FAT16)    val = -1;
+                       if(val == EOC_FAT16)    val = GETFATVALUE_EOC;
                } else {
                        VFS_ReadAt(Disk->fileHandle, ofs+cluster*4, 4, &val);
-                       if(val == EOC_FAT32)    val = -1;
+                       if(val == EOC_FAT32)    val = GETFATVALUE_EOC;
                }
        #if CACHE_FAT
        }
@@ -108,6 +110,7 @@ Uint32 FAT_int_AllocateCluster(tFAT_VolInfo *Disk, Uint32 Previous)
                }
                        
                Mutex_Release(&Disk->lFAT);
+               LOG("Allocated cluster %x", ret);
                return ret;
        }
        else
@@ -137,7 +140,7 @@ Uint32 FAT_int_AllocateCluster(tFAT_VolInfo *Disk, Uint32 Previous)
                        
                        // Search within the same block as the previous cluster first
                        do {
-                               VFS_ReadAt(Disk->fileHandle, base + block, block_size, sector_data);
+                               VFS_ReadAt(Disk->fileHandle, base + block*block_size, block_size, sector_data);
                                for( block_ofs = 0; block_ofs < ents_per_block_12; block_ofs ++ )
                                {
                                        Uint32  *valptr = (void*)( sector_data + block_ofs / 2 * 3 );
@@ -166,16 +169,21 @@ Uint32 FAT_int_AllocateCluster(tFAT_VolInfo *Disk, Uint32 Previous)
                                VFS_WriteAt(Disk->fileHandle, base + block, block_size, sector_data);
        
                                // Note the new cluster in the chain
-                               VFS_ReadAt(Disk->fileHandle, base + (Previous>>1)*3, 3, &val); 
-                               if( ret & 1 ) {
-                                       val &= 0x000FFF;
-                                       val |= ret << 12;
-                               }
-                               else {
-                                       val &= 0xFFF000;
-                                       val |= ret << 0;
+                               if( Previous != -1 )
+                               {
+                                       LOG("Updating cluster %x to point to %x (offset %x)", Previous, ret,
+                                               base + (Previous>>1)*3);
+                                       VFS_ReadAt(Disk->fileHandle, base + (Previous>>1)*3, 3, &val); 
+                                       if( Previous & 1 ) {
+                                               val &= 0x000FFF;
+                                               val |= ret << 12;
+                                       }
+                                       else {
+                                               val &= 0xFFF000;
+                                               val |= ret << 0;
+                                       }
+                                       VFS_WriteAt(Disk->fileHandle, base + (Previous>>1)*3, 3, &val);
                                }
-                               VFS_WriteAt(Disk->fileHandle, base + (Previous>>1)*3, 3, &val);
                        }
                        break;
                case FAT16:
@@ -190,6 +198,7 @@ Uint32 FAT_int_AllocateCluster(tFAT_VolInfo *Disk, Uint32 Previous)
                        break;
                }
                Mutex_Release(&Disk->lFAT);
+               LOG("Allocated cluster %x", ret);
                return ret;
        #if CACHE_FAT
        }