Modules/FAT - HUGE Rewrite to driver, with experimental write support

[tpg/acess2.git] / KernelLand / Modules / Filesystems / FAT / common.h

diff --git a/KernelLand/Modules/Filesystems/FAT/common.h b/KernelLand/Modules/Filesystems/FAT/common.h
new file mode 100644 (file)
index 0000000..340fff0
--- /dev/null
+++ b/KernelLand/Modules/Filesystems/FAT/common.h
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+/*
+ * Acess2 FAT Filesystem Driver
+ * - By John Hodge (thePowersGang)
+ * 
+ * common.h
+ * - FAT internal common header
+ */
+#ifndef _FS__FAT__COMMON_H_
+#define _FS__FAT__COMMON_H_
+
+#include "fs_fat.h"
+#include <vfs.h>
+
+#define CACHE_FAT      0       //!< Caches the FAT in memory
+#define USE_LFN                1       //!< Enables the use of Long File Names
+#define        SUPPORT_WRITE   1       //!< Enables write support
+
+#define FAT_FLAG_DIRTY 0x10000
+#define FAT_FLAG_DELETE        0x20000
+
+typedef struct sFAT_VolInfo tFAT_VolInfo;
+#if USE_LFN
+typedef struct sFAT_LFNCacheEnt        tFAT_LFNCacheEnt;
+typedef struct sFAT_LFNCache   tFAT_LFNCache;
+#endif
+typedef struct sFAT_CachedNode tFAT_CachedNode;
+
+/**
+ * \brief Internal IDs for FAT types
+ */
+enum eFatType
+{
+       FAT12,  //!< FAT12 Volume
+       FAT16,  //!< FAT16 Volume
+       FAT32,  //!< FAT32 Volume
+};
+
+// === TYPES ===
+struct sFAT_VolInfo
+{
+        int    fileHandle;     //!< File Handle
+       enum eFatType   type;   //!< FAT Variant
+       char    name[12];       //!< Volume Name (With NULL Terminator)
+       Uint32  firstDataSect;  //!< First data sector
+       Uint32  rootOffset;     //!< Root Offset (clusters)
+       Uint32  ClusterCount;   //!< Total Cluster Count
+       fat_bootsect    bootsect;       //!< Boot Sector
+       tVFS_Node       rootNode;       //!< Root Node
+        int    BytesPerCluster;
+       
+       tMutex  lNodeCache;
+       tFAT_CachedNode *NodeCache;
+       
+       tMutex  lFAT;           //!< Lock to prevent double-writing to the FAT
+       #if CACHE_FAT
+       Uint32  *FATCache;      //!< FAT Cache
+       #endif
+};
+
+#if USE_LFN
+/**
+ * \brief Long-Filename cache entry
+ */
+struct sFAT_LFNCacheEnt
+{
+        int    ID;
+       Uint16  Data[256];
+};
+/**
+ * \brief Long-Filename cache
+ */
+struct sFAT_LFNCache
+{
+        int    NumEntries;
+       tFAT_LFNCacheEnt        Entries[];
+};
+#endif
+
+struct sFAT_CachedNode
+{
+       struct sFAT_CachedNode  *Next;
+       tVFS_Node       Node;
+};
+
+// --- General Helpers ---
+extern int     FAT_int_GetAddress(tVFS_Node *Node, Uint64 Offset, Uint64 *Addr, Uint32 *Cluster);
+
+// --- Node Caching ---
+// NOTE: FAT uses its own node cache that references by cluster (not the inode value that the Inode_* cache uses)
+//       because tVFS_Node.Inode contains the parent directory inode
+extern tVFS_Node       *FAT_int_CreateNode(tVFS_Node *Parent, fat_filetable *Entry);
+extern tVFS_Node       *FAT_int_CreateIncompleteDirNode(tFAT_VolInfo *Disk, Uint32 Cluster);
+extern tVFS_Node       *FAT_int_GetNode(tFAT_VolInfo *Disk, Uint32 Cluster);
+extern void    FAT_int_DerefNode(tVFS_Node *Node);
+extern void    FAT_int_ClearNodeCache(tFAT_VolInfo *Disk);
+
+// --- FAT Access ---
+extern Uint32  FAT_int_GetFatValue(tFAT_VolInfo *Disk, Uint32 Cluster);
+#if SUPPORT_WRITE
+extern Uint32  FAT_int_AllocateCluster(tFAT_VolInfo *Disk, Uint32 Previous);
+extern Uint32  FAT_int_FreeCluster(tFAT_VolInfo *Disk, Uint32 Cluster);
+#endif
+extern void    FAT_int_ReadCluster(tFAT_VolInfo *Disk, Uint32 Cluster, int Length, void *Buffer);
+extern void    FAT_int_WriteCluster(tFAT_VolInfo *Disk, Uint32 Cluster, const void *Buffer);
+
+// --- Directory Access ---
+extern char    *FAT_ReadDir(tVFS_Node *Node, int ID);
+extern tVFS_Node       *FAT_FindDir(tVFS_Node *Node, const char *Name);
+extern tVFS_Node       *FAT_GetNodeFromINode(tVFS_Node *Root, Uint64 Inode);
+extern int     FAT_int_GetEntryByCluster(tVFS_Node *DirNode, Uint32 Cluster, fat_filetable *Entry);
+#if SUPPORT_WRITE
+extern int     FAT_int_WriteDirEntry(tVFS_Node *Node, int ID, fat_filetable *Entry);
+extern int     FAT_Mknod(tVFS_Node *Node, const char *Name, Uint Flags);
+extern int     FAT_Link(tVFS_Node *DirNode, const char *NewName, tVFS_Node *Node);
+extern int     FAT_Unlink(tVFS_Node *DirNode, const char *OldName);
+#endif
+extern void    FAT_CloseFile(tVFS_Node *node);
+
+// === GLOBALS ===
+extern tVFS_NodeType   gFAT_DirType;
+extern tVFS_NodeType   gFAT_FileType;
+
+#endif
+