From: John Hodge <tpg@mutabah.net>
Date: Sat, 14 Jul 2012 12:24:10 +0000 (+0800)
Subject: Kernel - Added .Detect method to VFS drivers
X-Git-Tag: rel0.15~611^2~34
X-Git-Url: https://git.ucc.asn.au/?a=commitdiff_plain;h=891868f0b4d64eb274b5810ac0c4f0a53d104114;p=tpg%2Facess2.git

Kernel - Added .Detect method to VFS drivers
---

diff --git a/KernelLand/Kernel/include/vfs.h b/KernelLand/Kernel/include/vfs.h
index 91dcd693..9cb9e5de 100644
--- a/KernelLand/Kernel/include/vfs.h
+++ b/KernelLand/Kernel/include/vfs.h
@@ -339,6 +339,15 @@ typedef struct sVFS_Driver
 	 */
 	Uint	Flags;
 	
+	/**
+	 * \brief Detect if a volume is accessible using this driver
+	 * \return Boolean success (with higher numbers being higher priority)
+	 *
+	 * E.g. FAT would return 1 as it's the lowest common denominator while ext2 might return 2,
+	 * because it can be embedded in a FAT volume (and is a more fully featured filesystem).
+	 */
+	 int	(*Detect)(int FD);
+
 	/**
 	 * \brief Callback to mount a device
 	 */
diff --git a/KernelLand/Kernel/vfs/fs/devfs.c b/KernelLand/Kernel/vfs/fs/devfs.c
index 354f4020..9ab2b7b4 100644
--- a/KernelLand/Kernel/vfs/fs/devfs.c
+++ b/KernelLand/Kernel/vfs/fs/devfs.c
@@ -20,7 +20,9 @@ tVFS_Node	*DevFS_FindDir(tVFS_Node *Node, const char *Name);
 
 // === GLOBALS ===
 tVFS_Driver	gDevFS_Info = {
-	"devfs", 0, DevFS_InitDevice, DevFS_Unmount, NULL
+	.Name = "devfs",
+	.InitDevice = DevFS_InitDevice,
+	.Unmount = DevFS_Unmount
 	};
 tVFS_NodeType	gDevFS_DirType = {
 	.TypeName = "DevFS-Dir",
diff --git a/KernelLand/Kernel/vfs/fs/root.c b/KernelLand/Kernel/vfs/fs/root.c
index 6c45f40e..e97231bb 100644
--- a/KernelLand/Kernel/vfs/fs/root.c
+++ b/KernelLand/Kernel/vfs/fs/root.c
@@ -22,7 +22,8 @@ tRamFS_File	*Root_int_AllocFile(void);
 
 // === GLOBALS ===
 tVFS_Driver	gRootFS_Info = {
-	"rootfs", 0, Root_InitDevice, NULL, NULL
+	.Name = "rootfs", 
+	.InitDevice = Root_InitDevice
 	};
 tRamFS_File	RootFS_Files[MAX_FILES];
 tVFS_ACL	RootFS_DirACLs[3] = {
diff --git a/KernelLand/Modules/Filesystems/Ext2/ext2.c b/KernelLand/Modules/Filesystems/Ext2/ext2.c
index f40689e0..971ef28e 100644
--- a/KernelLand/Modules/Filesystems/Ext2/ext2.c
+++ b/KernelLand/Modules/Filesystems/Ext2/ext2.c
@@ -17,6 +17,7 @@ extern tVFS_NodeType	gExt2_DirType;
  int	Ext2_Install(char **Arguments);
  int	Ext2_Cleanup(void);
 // - Interface Functions
+ int    	Ext2_Detect(int FD);
 tVFS_Node	*Ext2_InitDevice(const char *Device, const char **Options);
 void		Ext2_Unmount(tVFS_Node *Node);
 void		Ext2_CloseFile(tVFS_Node *Node);
@@ -31,7 +32,11 @@ MODULE_DEFINE(0, VERSION, FS_Ext2, Ext2_Install, Ext2_Cleanup);
 tExt2_Disk	gExt2_disks[6];
  int	giExt2_count = 0;
 tVFS_Driver	gExt2_FSInfo = {
-	"ext2", 0, Ext2_InitDevice, Ext2_Unmount, NULL
+	.Name = "ext2",
+	.Detect = Ext2_Detect,
+	.InitDevice = Ext2_InitDevice,
+	.Unmount = Ext2_Unmount,
+	.GetNodeFromINode = NULL
 	};
 
 // === CODE ===
@@ -53,6 +58,31 @@ int Ext2_Cleanup(void)
 	return 0;
 }
 
+/**
+ * Detect if a volume is Ext2 formatted
+ */
+int Ext2_Detect(int FD)
+{
+	tExt2_SuperBlock	sb;
+	size_t	len;
+	
+	len = VFS_ReadAt(FD, 1024, 1024, &sb);
+
+	if( len != 1024 ) {
+		Log_Debug("Ext2", "_Detect: Read failed? (0x%x != 1024)", len);
+		return 0;
+	}
+	
+	switch(sb.s_magic)
+	{
+	case 0xEF53:
+		return 2;
+	default:
+		Log_Debug("Ext2", "_Detect: s_magic = 0x%x", sb.s_magic);
+		return 0;
+	}
+}
+
 /**
  \brief Initializes a device to be read by by the driver
  \param Device	String - Device to read from
diff --git a/KernelLand/Modules/Filesystems/FAT/fat.c b/KernelLand/Modules/Filesystems/FAT/fat.c
index ab91fcb3..f7ebafe5 100644
--- a/KernelLand/Modules/Filesystems/FAT/fat.c
+++ b/KernelLand/Modules/Filesystems/FAT/fat.c
@@ -27,6 +27,7 @@
 // === PROTOTYPES ===
 // --- Driver Core
  int	FAT_Install(char **Arguments);
+ int	FAT_Detect(int FD);
 tVFS_Node	*FAT_InitDevice(const char *device, const char **options);
 void	FAT_Unmount(tVFS_Node *Node);
 // --- Helpers
@@ -46,7 +47,13 @@ void	FAT_CloseFile(tVFS_Node *node);
 MODULE_DEFINE(0, VER2(0,80) /*v0.80*/, VFAT, FAT_Install, NULL, NULL);
 tFAT_VolInfo	gFAT_Disks[8];
  int	giFAT_PartCount = 0;
-tVFS_Driver	gFAT_FSInfo = {"fat", 0, FAT_InitDevice, FAT_Unmount, FAT_GetNodeFromINode, NULL};
+tVFS_Driver	gFAT_FSInfo = {
+	.Name = "fat",
+	.Detect = FAT_Detect,
+	.InitDevice = FAT_InitDevice,
+	.Unmount = FAT_Unmount,
+	.GetNodeFromINode = FAT_GetNodeFromINode
+};
 tVFS_NodeType	gFAT_DirType = {
 	.TypeName = "FAT-Dir",
 	.ReadDir = FAT_ReadDir,
@@ -78,6 +85,22 @@ int FAT_Install(char **Arguments)
 	return MODULE_ERR_OK;
 }
 
+/**
+ * \brief Detect if a file is a FAT device
+ */
+int FAT_Detect(int FD)
+{
+	fat_bootsect bs;
+	
+	if( VFS_ReadAt(FD, 0, 512, &bs) != 512) {
+		return 0;
+	}
+
+	if(bs.bps == 0 || bs.spc == 0)
+		return 0;
+	
+	return 1;
+}
 /**
  * \brief Reads the boot sector of a disk and prepares the structures for it
  */
diff --git a/KernelLand/Modules/Filesystems/NTFS/main.c b/KernelLand/Modules/Filesystems/NTFS/main.c
index dbda06e1..87f2a09a 100644
--- a/KernelLand/Modules/Filesystems/NTFS/main.c
+++ b/KernelLand/Modules/Filesystems/NTFS/main.c
@@ -23,7 +23,12 @@ void	NTFS_DumpEntry(tNTFS_Disk *Disk, Uint32 Entry);
 
 // === GLOBALS ===
 MODULE_DEFINE(0, 0x0A /*v0.1*/, FS_NTFS, NTFS_Install, NULL);
-tVFS_Driver	gNTFS_FSInfo = {"ntfs", 0, NTFS_InitDevice, NTFS_Unmount, NULL};
+tVFS_Driver	gNTFS_FSInfo = {
+	.Name = "ntfs",
+	.InitDevice = NTFS_InitDevice,
+	.Unmount = NTFS_Unmount,
+	.GetNodeFromINode = NULL
+};
 tVFS_NodeType	gNTFS_DirType = {
 	.TypeName = "NTFS-File",
 	.ReadDir = NTFS_ReadDir,